Search results for: background reduction
Commenced in January 2007
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Paper Count: 8971

Search results for: background reduction

301 Ordered Mesoporous Carbons of Different Morphology for Loading and Controlled Release of Active Pharmaceutical Ingredients

Authors: Aleksander Ejsmont, Aleksandra Galarda, Joanna Goscianska

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Smart porous carriers with defined structure and physicochemical properties are required for releasing the therapeutic drug with precise control of delivery time and location in the body. Due to their non-toxicity, ordered structure, chemical, and thermal stability, mesoporous carbons can be considered as modern carriers for active pharmaceutical ingredients (APIs) whose effectiveness needs frequent dosing algorithms. Such an API-carrier system, if programmed precisely, may stabilize the pharmaceutical and increase its dissolution leading to enhanced bioavailability. The substance conjugated with the material, through its prior adsorption, can later be successfully applied internally to the organism, as well as externally if the API release is feasible under these conditions. In the present study, ordered mesoporous carbons of different morphologies and structures, prepared by hard template method, were applied as carriers in the adsorption and controlled release of active pharmaceutical ingredients. In the first stage, the carbon materials were synthesized and functionalized with carboxylic groups by chemical oxidation using ammonium persulfate solution and then with amine groups. Materials obtained were thoroughly characterized with respect to morphology (scanning electron microscopy), structure (X-ray diffraction, transmission electron microscopy), characteristic functional groups (FT-IR spectroscopy), acid-base nature of surface groups (Boehm titration), parameters of the porous structure (low-temperature nitrogen adsorption) and thermal stability (TG analysis). This was followed by a series of tests of adsorption and release of paracetamol, benzocaine, and losartan potassium. Drug release experiments were performed in the simulated gastric fluid of pH 1.2 and phosphate buffer of pH 7.2 or 6.8 at 37.0 °C. The XRD patterns in the small-angle range and TEM images revealed that functionalization of mesoporous carbons with carboxylic or amine groups leads to the decreased ordering of their structure. Moreover, the modification caused a considerable reduction of the carbon-specific surface area and pore volume, but it simultaneously resulted in changing their acid-base properties. Mesoporous carbon materials exhibit different morphologies, which affect the host-guest interactions during the adsorption process of active pharmaceutical ingredients. All mesoporous carbons show high adsorption capacity towards drugs. The sorption capacity of materials is mainly affected by BET surface area and the structure/size matching between adsorbent and adsorbate. Selected APIs are linked to the surface of carbon materials mainly by hydrogen bonds, van der Waals forces, and electrostatic interactions. The release behavior of API is highly dependent on the physicochemical properties of mesoporous carbons. The release rate of APIs could be regulated by the introduction of functional groups and by changing the pH of the receptor medium. Acknowledgments—This research was supported by the National Science Centre, Poland (project SONATA-12 no: 2016/23/D/NZ7/01347).

Keywords: ordered mesoporous carbons, sorption capacity, drug delivery, carbon nanocarriers

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300 Eco-Politics of Infrastructure Development in and Around Protected Areas in Kenya: The Case of Nairobi National Park

Authors: Teresa Wanjiru Mbatia

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On 7th June 2011, the government Minister of Roads in Kenya announced the proposed construction of a major highway known as a southern bypass to run on the northern border of the Nairobi National Park. The following day on 8th June 2011, the chairperson of the Friends of Nairobi National Park (FONNAP) posted a protest statement on their website, with the heading, ‘Nairobi Park is Not a cake’ alerting its members and conservation groups, with the aim of getting support to the campaign against the government’s intention to hive off a section of the park for road construction. This was the first and earliest statement that led to a series of other events that culminated in conservationists and some other members of the public campaign against the government’s plan to hive off sections of the park to build road and railway infrastructure in or around the park. Together with other non-state actors, mostly non-governmental organisations in conservation/environment and tourism businesses, FoNNAP issued a series of other statements on social, print and electronic media to battle against road and railway construction. This paper examined the strategies, outcomes and interests of actors involved in opposing/proposing the development of transport infrastructure in and around the Nairobi National Park. Specifically, the objectives were to analyse the: (1) Arguments put forward by the eco-warriors to protest infrastructure development; (2) Background and interests of the eco-warriors; (3) Needs/interests and opinions of ordinary common citizens on transport infrastructural development, particularly in and around the urban nature reserve and (4) Final outcomes of the eco-politics surrounding infrastructure development in and around Nairobi National Park. The methodological approach used was environmental history and the social construction of nature. The study collected combined qualitative data using four main approaches, the grounded theory approach, narratives, case studies and a phenomenological approach. The information collected was analysed using critical discourse analysis. The major findings of the study were that under the guise of “public participation,” influential non-state actors have the capacity to perpetuate social-spatial inequalities in the form of curtailing the majority from accessing common public goods. A case in point in this study is how the efforts of powerful conservationists, environmentalists, and tourism businesspersons managed to stall the construction of much-needed road and railway infrastructure severally through litigations in lengthy environmental court processes involving injunctions and stop orders to the government bodies in charge. Moreover, powerful non-state actors were found to have formed informal and sometimes formal coalitions with politicians with selfish interests, which serves to deepen the exclusionary practices and the common good. The study concludes that mostly composed of certain types of elites (NGOs, business communities, politicians and privileged social-cultural groups), non-state actors have used participatory policies to advance their own interests at the expense of the majority whom they claim to represent. These practices are traced to the historically unjust social, political, and economic forces involved in the production of space in Nairobi.

Keywords: eco-politics, exclusion, infrastructure, Nairobi national park, non-state actors, protests

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299 Experimental and Modelling Performances of a Sustainable Integrated System of Conditioning for Bee-Pollen

Authors: Andrés Durán, Brian Castellanos, Marta Quicazán, Carlos Zuluaga-Domínguez

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Bee-pollen is an apicultural-derived food product, with a growing appreciation among consumers given the remarkable nutritional and functional composition, in particular, protein (24%), dietary fiber (15%), phenols (15 – 20 GAE/g) and carotenoids (600 – 900 µg/g). These properties are given by the geographical and climatic characteristics of the region where it is collected. There are several countries recognized by their pollen production, e.g. China, United States, Japan, Spain, among others. Beekeepers use traps in the entrance of the hive where bee-pollen is collected. After the removal of foreign particles and drying, this product is ready to be marketed. However, in countries located along the equator, the absence of seasons and a constant tropical climate throughout the year favors a more rapid spoilage condition for foods with elevated water activity. The climatic conditions also trigger the proliferation of microorganisms and insects. This, added to the factor that beekeepers usually do not have adequate processing systems for bee-pollen, leads to deficiencies in the quality and safety of the product. In contrast, the Andean region of South America, lying on equator, typically has a high production of bee-pollen of up to 36 kg/year/hive, being four times higher than in countries with marked seasons. This region is also located in altitudes superior to 2500 meters above sea level, having extremes sun ultraviolet radiation all year long. As a mechanism of defense of radiation, plants produce more secondary metabolites acting as antioxidant agents, hence, plant products such as bee-pollen contain remarkable more phenolics and carotenoids than collected in other places. Considering this, the improvement of bee-pollen processing facilities by technical modifications and the implementation of an integrated cleaning and drying system for the product in an apiary in the area was proposed. The beehives were modified through the installation of alternative bee-pollen traps to avoid sources of contamination. The processing facility was modified according to considerations of Good Manufacturing Practices, implementing the combined use of a cabin dryer with temperature control and forced airflow and a greenhouse-type solar drying system. Additionally, for the separation of impurities, a cyclone type system was implemented, complementary to a screening equipment. With these modifications, a decrease in the content of impurities and the microbiological load of bee-pollen was seen from the first stages, principally with a reduction of the presence of molds and yeasts and in the number of foreign animal origin impurities. The use of the greenhouse solar dryer integrated to the cabin dryer allowed the processing of larger quantities of product with shorter waiting times in storage, reaching a moisture content of about 6% and a water activity lower than 0.6, being appropriate for the conservation of bee-pollen. Additionally, the contents of functional or nutritional compounds were not affected, even observing an increase of up to 25% in phenols content and a non-significant decrease in carotenoids content and antioxidant activity.

Keywords: beekeeping, drying, food processing, food safety

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298 Review of Health Disparities in Migrants Attending the Emergency Department with Acute Mental Health Presentations

Authors: Jacqueline Eleonora Ek, Michael Spiteri, Chris Giordimaina, Pierre Agius

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Background: Malta is known for being a key player as a frontline country with regard to irregular immigration from Africa to Europe. Every year the island experiences an influx of migrants as boat movement across the Mediterranean continues to be a humanitarian challenge. Irregular immigration and applying for asylum is both a lengthy and mentally demanding process. Those doing so are often faced with multiple challenges, which can adversely affect their mental health. Between January and August 2020, Malta disembarked 2 162 people rescued at sea, 463 of them between July & August. Given the small size of the Maltese islands, this regulation places a disproportionately large burden on the country, creating a backlog in the processing of asylum applications resulting in increased time periods of detention. These delays reverberate throughout multiple management pathways resulting in prolonged periods of detention and challenging access to health services. Objectives: To better understand the spatial dimensions of this humanitarian crisis, this study aims to assess disparities in the acute medical management of migrants presenting to the emergency department (ED) with acute mental health presentations as compared to that of local and non-local residents. Method: In this retrospective study, 17795 consecutive ED attendances were reviewed to look for acute mental health presentations. These were further evaluated to assess discrepancies in transportation routes to hospital, nature of presenting complaint, effects of language barriers, use of CT brain, treatment given at ED, availability of psychiatric reviews, and final admission/discharge plans. Results: Of the ED attendances, 92.3% were local residents, and 7.7% were non-locals. Of the non-locals, 13.8% were migrants, and 86.2% were other-non-locals. Acute mental health presentations were seen in 1% of local residents; this increased to 20.6% in migrants. 56.4% of migrants attended with deliberate self-harm; this was lower in local residents, 28.9%. Contrastingly, in local residents, the most common presenting complaint was suicidal thought/ low mood 37.3%, the incidence was similar in migrants at 33.3%. The main differences included 12.8% of migrants presenting with refused oral intake while only 0.6% of local residents presented with the same complaints. 7.7% of migrants presented with a reduced level of consciousness, no local residents presented with this same issue. Physicians documented a language barrier in 74.4% of migrants. 25.6% were noted to be completely uncommunicative. Further investigations included the use of a CT scan in 12% of local residents and in 35.9% of migrants. The most common treatment administered to migrants was supportive fluids 15.4%, the most common in local residents was benzodiazepines 15.1%. Voluntary psychiatric admissions were seen in 33.3% of migrants and 24.7% of locals. Involuntary admissions were seen in 23% of migrants and 13.3% of locals. Conclusion: Results showed multiple disparities in health management. A meeting was held between entities responsible for migrant health in Malta, including the emergency department, primary health care, migrant detention services, and Malta Red Cross. Currently, national quality-improvement initiatives are underway to form new pathways to improve patient-centered care. These include an interpreter unit, centralized handover sheets, and a dedicated migrant health service.

Keywords: emergency department, communication, health, migration

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297 Evaluation of Forensic Pathology Practice Outside Germany – Experiences From 20 Years of Second Look Autopsies in Cooperation with the Institute of Legal Medicine Munich

Authors: Michael Josef Schwerer, Oliver Peschel

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Background: The sense and purpose of forensic postmortem examinations are undoubtedly the same in Institutes of Legal Medicine all over the world. Cause and manner of death must be determined, persons responsible for unnatural death must be brought to justice, and accidents demand changes in the respective scenarios to avoid future mishaps. The latter particularly concerns aircraft accidents, not only regarding consequences from criminal or civil law but also in pursuance of the International Civil Aviation Authority’s regulations, which demand lessons from mishap investigations to improve flight safety. Irrespective of the distinct circumstances of a given casualty or the respective questions in subsequent death investigations, a forensic autopsy is the basis for all further casework, the clue to otherwise hidden solutions, and the crucial limitation for final success when not all possible findings have been properly collected. This also implies that the targeted work of police forces and expert witnesses strongly depends on the quality of forensic pathology practice. Deadly events in foreign countries, which lead to investigations not only abroad but also in Germany, can be challenging in this context. Frequently, second-look autopsies after the repatriation of the deceased to Germany are requested by the legal authorities to ensure proper and profound documentation of all relevant findings. Aims and Methods: To validate forensic postmortem practice abroad, a retrospective study using the findings in the corresponding second-look autopsies in the Institute of Legal Medicine Munich over the last 20 years was carried out. New findings unreported in the previous autopsy were recorded and judged for their relevance to solving the respective case. Further, the condition of the corpse at the time of the second autopsy was rated to discuss artifacts mimicking evidence or the possibility of lost findings resulting from, e.g., decomposition. Recommendations for future handling of death cases abroad and efficient autopsy practice were pursued. Results and Discussion: Our re-evaluation confirmed a high quality of autopsy practice abroad in the vast majority of cases. However, in some casework, incomplete documentation of pathology findings was revealed along with either insufficient or misconducted dissection of organs. Further, some of the bodies showed missing parts of some organs, most probably resulting from sampling for histology studies during the first postmortem. For the aeromedical evaluation of a decedent’s health status prior to an aviation mishap, particularly lost or obscured findings in the heart, lungs, and brain impeded expert testimony. Moreover, incomplete fixation of the body or body parts for repatriation was seen in several cases. This particularly involved previously dissected organs deposited back into the body cavities at the end of the first autopsy. Conclusions and Recommendations: Detailed preparation in the first forensic autopsy avoids the necessity of a second-look postmortem in the majority of cases. To limit decomposition changes during repatriation from abroad, special care must be taken to include pre-dissected organs in the chemical fixation process, particularly when they are separated from the blood vessels and just deposited back into the body cavities.

Keywords: autopsy practice, second-look autopsy, retrospective study, quality standards, decomposition changes, repatriation

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296 Use of Zikani’s Ribosome Modulating Agents for Treating Recessive Dystrophic & Junctional Epidermolysis Bullosa with Nonsense Mutations

Authors: Mei Chen, Yingping Hou, Michelle Hao, Soheil Aghamohammadzadeh, Esteban Terzo, Roger Clark, Vijay Modur

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Background: Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a genetic skin condition characterized by skin tearing and unremitting blistering upon minimal trauma. Repeated blistering, fibrosis, and scarring lead to aggressive squamous cell carcinoma later in life. RDEB is caused by mutations in the COL7A1 gene encoding collagen type VII (C7), the major component of anchoring fibrils mediating epidermis-dermis adherence. Nonsense mutations in the COL7A1 gene of a subset of RDEB patients leads to premature termination codons (PTC). Similarly, most Junctional Epidermolysis Bullosa (JEB) cases are caused by nonsense mutations in the LAMB3 gene encoding the β3 subunit of laminin 332. Currently, there is an unmet need for the treatment of RDEB and JEB. Zikani Therapeutics has discovered an array of macrocyclic compounds with ring structures similar to macrolide antibiotics that can facilitate readthrough activity of nonsense mutations in the COL7A1 and LAMB3 genes by acting as Ribosome Modulating Agents (RMAs). The medicinal chemistry synthetic advancements of these macrocyclic compounds have allowed targeting the human ribosome while preserving the structural elements responsible for the safety and pharmacokinetic profile of clinically used macrolide antibiotics. Methods: C7 expression was used as a measure of readthrough activity by immunoblot assays in two primary human fibroblasts from RDEB patients (R578X/R578X and R163X/R1683X-COL7A1). Similarly, immunoblot assays in C325X/c.629-12T > A-LAMB3 keratinocytes were used to measure readthrough activity for JEB. The relative readthrough activity of each compound was measured relative to Gentamicin. An imaging-based fibroblast migration assay was used as an assessment of C7 functionality in RDEB-fibroblasts over 16-20 hrs. The incubation period for the above experiments was 48 hrs for RDEB fibroblasts and 72 hours for JEB keratinocytes. Results: 9 RMAs demonstrated increased protein expression in both patient RDEB fibroblasts. The highest readthrough activity at tested concentrations without cytotoxicities increased protein expression up to 179% of Gentamicin (400 µg/ml), with favored readthrough activity in R163X/R1683X-COL7A1 fibroblasts. Concurrent with protein expression, fibroblast hypermotility phenotype observed in RDEB was rescued by reducing motility by ~35% to WT levels (the same level as 690 µM Gentamicin treated cells). Laminin β3 expression was also shown to be increased by 6 RMAs in keratinocytes to 33-83% of (400 µg/ml) Gentamicin. Conclusions: To date, 9 RMAs have been identified that enhance the expression of functional C7 in a mutation-dependent manner in two different RDEB patient fibroblast backgrounds (R578X/R578X and R163X/R1683X-COL7A1). A further 6 RMAs have been identified that enhance the readthrough of C325X-LAMB3 in JEB patient keratinocytes. Based on the clinical trial conducted by us with topical gentamycin in 2017, Zikani’s RMAs achieve clinically significant levels of read-through for the treatment of recessive dystrophic and Junctional Epidermolysis Bullosa.

Keywords: epidermolysis bullosa, nonsense mutation, readthrough, ribosome modulation

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295 Effectiveness of Participatory Ergonomic Education on Pain Due to Work Related Musculoskeletal Disorders in Food Processing Industrial Workers

Authors: Salima Bijapuri, Shweta Bhatbolan, Sejalben Patel

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Ergonomics concerns the fitting of the environment and the equipment to the worker. Ergonomic principles can be employed in different dimensions of the industrial sector. Participation of all the stakeholders is the key to the formulation of a multifaceted and comprehensive approach to lessen the burden of occupational hazards. Taking responsibility for one’s own work activities by acquiring sufficient knowledge and potential to influence the practices and outcomes is the basis of participatory ergonomics and even hastens the process to identify workplace hazards. The study was aimed to check how participatory ergonomics can be effective in the management of work-related musculoskeletal disorders. Method: A mega kitchen was identified in a twin city of Karnataka, India. Consent was taken, and the screening of workers was done using observation methods. Kitchen work was structured to include different tasks, which included preparation, cooking, distributing, and serving food, packing food to be delivered to schools, dishwashing, cleaning and maintenance of kitchen and equipment, and receiving and storing raw material. Total 100 workers attended the education session on participatory ergonomics and its role in implementing the correct ergonomic practices, thus preventing WRMSDs. Demographic details and baseline data on related musculoskeletal pain and discomfort were collected using the Nordic pain questionnaire and VAS score pre- and post-study. Monthly visits were made, and the education sessions were reiterated on each visit, thus reminding, correcting, and problem-solving of each worker. After 9 months with a total of 4 such education session, the post education data was collected. The software SPSS 20 was used to analyse the collected data. Results: The majority of them (78%), depending on the availability and feasibility, participated in the intervention workshops were arranged four times. The average age of the participants was 39 years. The percentage of female participants was 79.49%, and 20.51% of participants comprised of males. The Nordic Musculoskeletal Questionnaire (NMQ) showed that knee pain was the most commonly reported complaint (62%) from the last 12 months with a mean VAS of 6.27, followed by low back pain. Post intervention, the mean VAS Score was reduced significantly to 2.38. The comparison of pre-post scores was made using Wilcoxon matched pairs test. Upon enquiring, it was found that, the participants learned the importance of applying ergonomics at their workplace which inturn was beneficial for them to handle any problems arising at their workplace on their own with self confidence. Conclusion: The participatory ergonomics proved effective with workers of mega kitchen, and it is a feasible and practical approach. The advantage of the given study area was that it had a sophisticated and ergonomically designed workstation; thus it was the lack of education and practical knowledge to use these stations was of utmost need. There was a significant reduction in VAS scores with the implementation of changes in the working style, and the knowledge of ergonomics helped to decrease physical load and improve musculoskeletal health.

Keywords: ergonomic awareness session, mega kitchen, participatory ergonomics, work related musculoskeletal disorders

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294 Participatory Monitoring Strategy to Address Stakeholder Engagement Impact in Co-creation of NBS Related Project: The OPERANDUM Case

Authors: Teresa Carlone, Matteo Mannocchi

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In the last decade, a growing number of International Organizations are pushing toward green solutions for adaptation to climate change. This is particularly true in the field of Disaster Risk Reduction (DRR) and land planning, where Nature-Based Solutions (NBS) had been sponsored through funding programs and planning tools. Stakeholder engagement and co-creation of NBS is growing as a practice and research field in environmental projects, fostering the consolidation of a multidisciplinary socio-ecological approach in addressing hydro-meteorological risk. Even thou research and financial interests are constantly spread, the NBS mainstreaming process is still at an early stage as innovative concepts and practices make it difficult to be fully accepted and adopted by a multitude of different actors to produce wide scale societal change. The monitoring and impact evaluation of stakeholders’ participation in these processes represent a crucial aspect and should be seen as a continuous and integral element of the co-creation approach. However, setting up a fit for purpose-monitoring strategy for different contexts is not an easy task, and multiple challenges emerge. In this scenario, the Horizon 2020 OPERANDUM project, designed to address the major hydro-meteorological risks that negatively affect European rural and natural territories through the co-design, co-deployment, and assessment of Nature-based Solution, represents a valid case study to test a monitoring strategy from which set a broader, general and scalable monitoring framework. Applying a participative monitoring methodology, based on selected indicators list that combines quantitative and qualitative data developed within the activity of the project, the paper proposes an experimental in-depth analysis of the stakeholder engagement impact in the co-creation process of NBS. The main focus will be to spot and analyze which factors increase knowledge, social acceptance, and mainstreaming of NBS, promoting also a base-experience guideline to could be integrated with the stakeholder engagement strategy in current and future similar strongly collaborative approach-based environmental projects, such as OPERANDUM. Measurement will be carried out through survey submitted at a different timescale to the same sample (stakeholder: policy makers, business, researchers, interest groups). Changes will be recorded and analyzed through focus groups in order to highlight causal explanation and to assess the proposed list of indicators to steer the conduction of similar activities in other projects and/or contexts. The idea of the paper is to contribute to the construction of a more structured and shared corpus of indicators that can support the evaluation of the activities of involvement and participation of various levels of stakeholders in the co-production, planning, and implementation of NBS to address climate change challenges.

Keywords: co-creation and collaborative planning, monitoring, nature-based solution, participation & inclusion, stakeholder engagement

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293 Seawater Desalination for Production of Highly Pure Water Using a Hydrophobic PTFE Membrane and Direct Contact Membrane Distillation (DCMD)

Authors: Ahmad Kayvani Fard, Yehia Manawi

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Qatar’s primary source of fresh water is through seawater desalination. Amongst the major processes that are commercially available on the market, the most common large scale techniques are Multi-Stage Flash distillation (MSF), Multi Effect distillation (MED), and Reverse Osmosis (RO). Although commonly used, these three processes are highly expensive down to high energy input requirements and high operating costs allied with maintenance and stress induced on the systems in harsh alkaline media. Beside that cost, environmental footprint of these desalination techniques are significant; from damaging marine eco-system, to huge land use, to discharge of tons of GHG and huge carbon footprint. Other less energy consuming techniques based on membrane separation are being sought to reduce both the carbon footprint and operating costs is membrane distillation (MD). Emerged in 1960s, MD is an alternative technology for water desalination attracting more attention since 1980s. MD process involves the evaporation of a hot feed, typically below boiling point of brine at standard conditions, by creating a water vapor pressure difference across the porous, hydrophobic membrane. Main advantages of MD compared to other commercially available technologies (MSF and MED) and specially RO are reduction of membrane and module stress due to absence of trans-membrane pressure, less impact of contaminant fouling on distillate due to transfer of only water vapor, utilization of low grade or waste heat from oil and gas industries to heat up the feed up to required temperature difference across the membrane, superior water quality, and relatively lower capital and operating cost. To achieve the objective of this study, state of the art flat-sheet cross-flow DCMD bench scale unit was designed, commissioned, and tested. The objective of this study is to analyze the characteristics and morphology of the membrane suitable for DCMD through SEM imaging and contact angle measurement and to study the water quality of distillate produced by DCMD bench scale unit. Comparison with available literature data is undertaken where appropriate and laboratory data is used to compare a DCMD distillate quality with that of other desalination techniques and standards. Membrane SEM analysis showed that the PTFE membrane used for the study has contact angle of 127º with highly porous surface supported with less porous and bigger pore size PP membrane. Study on the effect of feed solution (salinity) and temperature on water quality of distillate produced from ICP and IC analysis showed that with any salinity and different feed temperature (up to 70ºC) the electric conductivity of distillate is less than 5 μS/cm with 99.99% salt rejection and proved to be feasible and effective process capable of consistently producing high quality distillate from very high feed salinity solution (i.e. 100000 mg/L TDS) even with substantial quality difference compared to other desalination methods such as RO and MSF.

Keywords: membrane distillation, waste heat, seawater desalination, membrane, freshwater, direct contact membrane distillation

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292 Multi-Dimensional Experience of Processing Textual and Visual Information: Case Study of Allocations to Places in the Mind’s Eye Based on Individual’s Semantic Knowledge Base

Authors: Joanna Wielochowska, Aneta Wielochowska

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Whilst the relationship between scientific areas such as cognitive psychology, neurobiology and philosophy of mind has been emphasized in recent decades of scientific research, concepts and discoveries made in both fields overlap and complement each other in their quest for answers to similar questions. The object of the following case study is to describe, analyze and illustrate the nature and characteristics of a certain cognitive experience which appears to display features of synaesthesia, or rather high-level synaesthesia (ideasthesia). The following research has been conducted on the subject of two authors, monozygotic twins (both polysynaesthetes) experiencing involuntary associations of identical nature. Authors made attempts to identify which cognitive and conceptual dependencies may guide this experience. Operating on self-introduced nomenclature, the described phenomenon- multi-dimensional processing of textual and visual information- aims to define a relationship that involuntarily and immediately couples the content introduced by means of text or image a sensation of appearing in a certain place in the mind’s eye. More precisely: (I) defining a concept introduced by means of textual content during activity of reading or writing, or (II) defining a concept introduced by means of visual content during activity of looking at image(s) with simultaneous sensation of being allocated to a given place in the mind’s eye. A place can be then defined as a cognitive representation of a certain concept. During the activity of processing information, a person has an immediate and involuntary feel of appearing in a certain place themselves, just like a character of a story, ‘observing’ a venue or a scenery from one or more perspectives and angles. That forms a unique and unified experience, constituting a background mental landscape of text or image being looked at. We came to a conclusion that semantic allocations to a given place could be divided and classified into the categories and subcategories and are naturally linked with an individual’s semantic knowledge-base. A place can be defined as a representation one’s unique idea of a given concept that has been established in their semantic knowledge base. A multi-level structure of selectivity of places in the mind’s eye, as a reaction to a given information (one stimuli), draws comparisons to structures and patterns found in botany. Double-flowered varieties of flowers and a whorl system (arrangement) which is characteristic to components of some flower species were given as an illustrative example. A composition of petals that fan out from one single point and wrap around a stem inspired an idea that, just like in nature, in philosophy of mind there are patterns driven by the logic specific to a given phenomenon. The study intertwines terms perceived through the philosophical lens, such as definition of meaning, subjectivity of meaning, mental atmosphere of places, and others. Analysis of this rare experience aims to contribute to constantly developing theoretical framework of the philosophy of mind and influence the way human semantic knowledge base and processing given content in terms of distinguishing between information and meaning is researched.

Keywords: information and meaning, information processing, mental atmosphere of places, patterns in nature, philosophy of mind, selectivity, semantic knowledge base, senses, synaesthesia

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291 Effect of Non-Thermal Plasma, Chitosan and Polymyxin B on Quorum Sensing Activity and Biofilm of Pseudomonas aeruginosa

Authors: Alena Cejkova, Martina Paldrychova, Jana Michailidu, Olga Matatkova, Jan Masak

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Increasing the resistance of pathogenic microorganisms to many antibiotics is a serious threat to the treatment of infectious diseases and cleaning medical instruments. It should be added that the resistance of microbial populations growing in biofilms is often up to 1000 times higher compared to planktonic cells. Biofilm formation in a number of microorganisms is largely influenced by the quorum sensing regulatory mechanism. Finding external factors such as natural substances or physical processes that can interfere effectively with quorum sensing signal molecules should reduce the ability of the cell population to form biofilm and increase the effectiveness of antibiotics. The present work is devoted to the effect of chitosan as a representative of natural substances with anti-biofilm activity and non- thermal plasma (NTP) alone or in combination with polymyxin B on biofilm formation of Pseudomonas aeruginosa. Particular attention was paid to the influence of these agents on the level of quorum sensing signal molecules (acyl-homoserine lactones) during planktonic and biofilm cultivations. Opportunistic pathogenic strains of Pseudomonas aeruginosa (DBM 3081, DBM 3777, ATCC 10145, ATCC 15442) were used as model microorganisms. Cultivations of planktonic and biofilm populations in 96-well microtiter plates on horizontal shaker were used for determination of antibiotic and anti-biofilm activity of chitosan and polymyxin B. Biofilm-growing cells on titanium alloy, which is used for preparation of joint replacement, were exposed to non-thermal plasma generated by cometary corona with a metallic grid for 15 and 30 minutes. Cultivation followed in fresh LB medium with or without chitosan or polymyxin B for next 24 h. Biofilms were quantified by crystal violet assay. Metabolic activity of the cells in biofilm was measured using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) colorimetric test based on the reduction of MTT into formazan by the dehydrogenase system of living cells. Activity of N-acyl homoserine lactones (AHLs) compounds involved in the regulation of biofilm formation was determined using Agrobacterium tumefaciens strain harboring a traG::lacZ/traR reporter gene responsive to AHLs. The experiments showed that both chitosan and non-thermal plasma reduce the AHLs level and thus the biofilm formation and stability. The effectiveness of both agents was somewhat strain dependent. During the eradication of P. aeruginosa DBM 3081 biofilm on titanium alloy induced by chitosan (45 mg / l) there was an 80% decrease in AHLs. Applying chitosan or NTP on the P. aeruginosa DBM 3777 biofilm did not cause a significant decrease in AHLs, however, in combination with both (chitosan 55 mg / l and NTP 30 min), resulted in a 70% decrease in AHLs. Combined application of NTP and polymyxin B allowed reduce antibiotic concentration to achieve the same level of AHLs inhibition in P. aeruginosa ATCC 15442. The results shown that non-thermal plasma and chitosan have considerable potential for the eradication of highly resistant P. aeruginosa biofilms, for example on medical instruments or joint implants.

Keywords: anti-biofilm activity, chitosan, non-thermal plasma, opportunistic pathogens

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290 Antibiotic Prophylaxis Habits in Oral Implant Surgery in the Netherlands: A Cross-Sectional Survey

Authors: Fabio Rodriguez Sanchez, Josef Bruers, Iciar Arteagoitia, Carlos Rodriguez Andres

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Background: Oral implants are a routine treatment to replace lost teeth. Although they have a high rate of success, implant failures do occur. Perioperative antibiotics have been suggested to prevent postoperative infections and dental implant failures, but they remain a controversial treatment among healthy patients. The objective of this study was to determine whether antibiotic prophylaxis is a common treatment in the Netherlands among general dentists, maxillofacial-surgeons, periodontists and implantologists in conjunction with oral implant surgery among healthy patients and to assess the nature of antibiotics prescriptions in order to evaluate whether any consensus has been reached and the current recommendations are being followed. Methodology: Observational cross-sectional study based on a web-survey reported according to the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines. A validated questionnaire, developed by Deeb et al. (2015), was translated and slightly adjusted to circumstances in the Netherlands. It was used with the explicit permission of the authors. This questionnaire contained both close-ended and some open-ended questions in relation to the following topics: demographics, qualification, antibiotic type, prescription-duration and dosage. An email was sent February 2018 to a sample of 600 general dentists and all 302 oral implantologists, periodontists and maxillofacial surgeons who were recognized by the Dutch Association of Oral Implantology (NVOI) as oral health care providers placing oral implants. The email included a brief introduction about the study objectives and a link to the web questionnaire, which could be filled in anonymously. Overall, 902 questionnaires were sent. However, 29 questionnaires were not correctly received due to an incorrect email address. So a total number of 873 professionals were reached. Collected data were analyzed using SPSS (IBM Corp., released 2012, Armonk, NY). Results: The questionnaire was sent back by a total number of 218 participants (response rate=24.2%), 45 female (20.8%) and 171 male (79.2%). Two respondents were excluded from the study group because they were not currently working as oral health providers. Overall 151 (69.9%) placed oral implants on regular basis. Approximately 79 (52.7%) of these participants prescribed antibiotics only in determined situations, 66 (44.0%) prescribed antibiotics always and 5 dentists (3.3%) did not prescribe antibiotics at all when placing oral implants. Overall, 83 participants who prescribed antibiotics, did so both pre- and postoperatively (58.5%), 12 exclusively postoperative (8.5%), and 47 followed an exclusive preoperative regime (33.1%). A single dose of 2,000 mg amoxicillin orally 1-hour prior treatment was the most prescribed preoperative regimen. The most frequent prescribed postoperative regimen was 500 mg amoxicillin three times daily for 7 days after surgery. On average, oral health professionals prescribed 6,923 mg antibiotics in conjunction with oral implant surgery, varying from 500 to 14,600 mg. Conclusions: Antibiotic prophylaxis in conjunction with oral implant surgery is prescribed in the Netherlands on a rather large scale. Dutch professionals might prescribe antibiotics more cautiously than in other countries and there seems to be a lower range on the different antibiotic types and regimens being prescribed. Anyway, recommendations based on last-published evidence are frequently not being followed.

Keywords: clinical decision making, infection control, antibiotic prophylaxis, dental implants

Procedia PDF Downloads 128
289 Ultrafiltration Process Intensification for Municipal Wastewater Reuse: Water Quality, Optimization of Operating Conditions and Fouling Management

Authors: J. Yang, M. Monnot, T. Eljaddi, L. Simonian, L. Ercolei, P. Moulin

Abstract:

The application of membrane technology to wastewater treatment has expanded rapidly under increasing stringent legislation and environmental protection requirements. At the same time, the water resource is becoming precious, and water reuse has gained popularity. Particularly, ultrafiltration (UF) is a very promising technology for water reuse as it can retain organic matters, suspended solids, colloids, and microorganisms. Nevertheless, few studies dealing with operating optimization of UF as a tertiary treatment for water reuse on a semi-industrial scale appear in the literature. Therefore, this study aims to explore the permeate water quality and to optimize operating parameters (maximizing productivity and minimizing irreversible fouling) through the operation of a UF pilot plant under real conditions. The fully automatic semi-industrial UF pilot plant with periodic classic backwashes (CB) and air backwashes (AB) was set up to filtrate the secondary effluent of an urban wastewater treatment plant (WWTP) in France. In this plant, the secondary treatment consists of a conventional activated sludge process followed by a sedimentation tank. The UF process was thus defined as a tertiary treatment and was operated under constant flux. It is important to note that a combination of CB and chlorinated AB was used for better fouling management. The 200 kDa hollow fiber membrane was used in the UF module, with an initial permeability (for WWTP outlet water) of 600 L·m-2·h⁻¹·bar⁻¹ and a total filtration surface of 9 m². Fifteen filtration conditions with different fluxes, filtration times, and air backwash frequencies were operated for more than 40 hours of each to observe their hydraulic filtration performances. Through comparison, the best sustainable condition was flux at 60 L·h⁻¹·m⁻², filtration time at 60 min, and backwash frequency of 1 AB every 3 CBs. The optimized condition stands out from the others with > 92% water recovery rates, better irreversible fouling control, stable permeability variation, efficient backwash reversibility (80% for CB and 150% for AB), and no chemical washing occurrence in 40h’s filtration. For all tested conditions, the permeate water quality met the water reuse guidelines of the World Health Organization (WHO), French standards, and the regulation of the European Parliament adopted in May 2020, setting minimum requirements for water reuse in agriculture. In permeate: the total suspended solids, biochemical oxygen demand, and turbidity were decreased to < 2 mg·L-1, ≤ 10 mg·L⁻¹, < 0.5 NTU respectively; the Escherichia coli and Enterococci were > 5 log removal reduction, the other required microorganisms’ analysis were below the detection limits. Additionally, because of the COVID-19 pandemic, coronavirus SARS-CoV-2 was measured in raw wastewater of WWTP, UF feed, and UF permeate in November 2020. As a result, the raw wastewater was tested positive above the detection limit but below the quantification limit. Interestingly, the UF feed and UF permeate were tested negative to SARS-CoV-2 by these PCR assays. In summary, this work confirms the great interest in UF as intensified tertiary treatment for water reuse and gives operational indications for future industrial-scale production of reclaimed water.

Keywords: semi-industrial UF pilot plant, water reuse, fouling management, coronavirus

Procedia PDF Downloads 99
288 Tip-Enhanced Raman Spectroscopy with Plasmonic Lens Focused Longitudinal Electric Field Excitation

Authors: Mingqian Zhang

Abstract:

Tip-enhanced Raman spectroscopy (TERS) is a scanning probe technique for individual objects and structured surfaces investigation that provides a wealth of enhanced spectral information with nanoscale spatial resolution and high detection sensitivity. It has become a powerful and promising chemical and physical information detection method in the nanometer scale. The TERS technique uses a sharp metallic tip regulated in the near-field of a sample surface, which is illuminated with a certain incident beam meeting the excitation conditions of the wave-vector matching. The local electric field, and, consequently, the Raman scattering, from the sample in the vicinity of the tip apex are both greatly tip-enhanced owning to the excitation of localized surface plasmons and the lightning-rod effect. Typically, a TERS setup is composed of a scanning probe microscope, excitation and collection optical configurations, and a Raman spectroscope. In the illumination configuration, an objective lens or a parabolic mirror is always used as the most important component, in order to focus the incident beam on the tip apex for excitation. In this research, a novel TERS setup was built up by introducing a plasmonic lens to the excitation optics as a focusing device. A plasmonic lens with symmetry breaking semi-annular slits corrugated on gold film was designed for the purpose of generating concentrated sub-wavelength light spots with strong longitudinal electric field. Compared to conventional far-field optical components, the designed plasmonic lens not only focuses an incident beam to a sub-wavelength light spot, but also realizes a strong z-component that dominants the electric field illumination, which is ideal for the excitation of tip-enhancement. Therefore, using a PL in the illumination configuration of TERS contributes to improve the detection sensitivity by both reducing the far-field background and effectively exciting the localized electric field enhancement. The FDTD method was employed to investigate the optical near-field distribution resulting from the light-nanostructure interaction. And the optical field distribution was characterized using an scattering-type scanning near-field optical microscope to demonstrate the focusing performance of the lens. The experimental result is in agreement with the theoretically calculated one. It verifies the focusing performance of the plasmonic lens. The optical field distribution shows a bright elliptic spot in the lens center and several arc-like side-lobes on both sides. After the focusing performance was experimentally verified, the designed plasmonic lens was used as a focusing component in the excitation configuration of TERS setup to concentrate incident energy and generate a longitudinal optical field. A collimated linearly polarized laser beam, with along x-axis polarization, was incident from the bottom glass side on the plasmonic lens. The incident light focused by the plasmonic lens interacted with the silver-coated tip apex and enhanced the Raman signal of the sample locally. The scattered Raman signal was gathered by a parabolic mirror and detected with a Raman spectroscopy. Then, the plasmonic lens based setup was employed to investigate carbon nanotubes and TERS experiment was performed. Experimental results indicate that the Raman signal is considerably enhanced which proves that the novel TERS configuration is feasible and promising.

Keywords: longitudinal electric field, plasmonics, raman spectroscopy, tip-enhancement

Procedia PDF Downloads 357
287 Nanocomposite Effect Based on Silver Nanoparticles and Anemposis Californica Extract as Skin Restorer

Authors: Maria Zulema Morquecho Vega, Fabiola CarolinaMiranda Castro, Rafael Verdugo Miranda, Ignacio Yocupicio Villegas, Ana lidia Barron Raygoza, Martin enrique MArquez Cordova, Jose Alberto Duarte Moller

Abstract:

Background: Anemopsis californica, also called (tame grass) belongs to the Saururaceae family small, green plant. The blade is long and wide. Gives a white flower. The plant population is only found in humid, swampy habitats, it grows where there is water, along the banks of streams and water holes. In the winter, it dries up. The leaves, rhizomes, or roots of this plant have been used to treat a range of diseases. Some of its healing properties are used to treat wounds, cold and flu symptoms, spasmodic cough, infection, pain and inflammation, burns, swollen feet, as well as lung ailments, asthma, circulatory problems (varicose veins), rheumatoid arthritis, purifies blood, helps in urinary and digestive tract diseases, sores and healing, for headache, sore throat, diarrhea, kidney pain. The tea made from the leaves and roots is used to treat uterine cancer, womb cancer, relieves menstrual pain and stops excessive bleeding after childbirth. It is also used as a gynecological treatment for infections, hemorrhoids, candidiasis and vaginitis. Objective: To study the cytotoxicity of gels prepared with silver nanoparticles in AC extract combined with chitosan, collagen and hyaluronic acid as an alternative therapy for skin conditions. Methods: The Ag NPs were synthesized according to the following method. A 0.3 mg/mL solution is prepared in 10 ml of deionized water, adjust to pH 12 with NaOH, stirring is maintained constant magnetic and a temperature of 80 °C. Subsequently, 100 ul of a 0.1 M AgNO3 solution and kept stirring constantly for 15 min. Once the reaction is complete, measurements are performed by UV-Vis. A gel was prepared in a 5% solution of acetic acid with the respective nanoparticles and AC extract of silver in the extract of AC. Chitosan is added until the process begins to occur gel. At that time, collagen will be added in a ratio of 3 to 5 drops, and later, hyaluronic acid in 2% of the total compound formed. Finally, after resting for 24 hours, the cytotoxic effect of the gels was studied. in the presence of highly positive bacteria Staphylococcus aureus and highly negative for Escherichia coli. Cultures will be incubated for 24 hours in the presence of the compound and compared with the reference. Results: Silver nanoparticles obtained had a spherical shape and sizes among 20 and 30 nm. UV-Vis spectra confirm the presence of silver nanoparticles showing a surface plasmon around 420 nm. Finally, the test in presence of bacteria yield a good antibacterial property of this nanocompound and tests in people were successful. Conclusion: Gel prepared by biogenic synthesis shown beneficious effects in severe acne, acne vulgaris and wound healing with diabetic patients.

Keywords: anemopsis californica, nanomedicina, biotechnology, biomedicine

Procedia PDF Downloads 88
286 Simultech - Innovative Country-Wide Ultrasound Training Center

Authors: Yael Rieder, Yael Gilboa, S. O. Adva, Efrat Halevi, Ronnie Tepper

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Background: Operation of ultrasound equipment is a core skill for many clinical specialties. As part of the training program at -Simultech- a simulation center for Ob\Gyn at the Meir Medical Center, Israel, teaching how to operate ultrasound equipment requires dealing with misunderstandings of spatial and 3D orientation, failure of the operator to hold a transducer correctly, and limited ability to evaluate the data on the screen. We have developed a platform intended to endow physicians and sonographers with clinical and operational skills of obstetric ultrasound. Simultech's simulations are focused on medical knowledge, risk management, technology operations and physician-patient communication. The simulations encompass extreme work conditions. Setup: Between eight and ten of the eight hundred and fifty physicians and sonographers of the Clalit health services from seven hospitals and eight community centers across Israel, participate in individual Ob/Gyn training sessions each week. These include Ob/Gyn specialists, experts, interns, and sonographers. Innovative teaching and training methodologies: The six-hour training program includes: (1) An educational computer program that challenges trainees to deal with medical questions based upon ultrasound pictures and films. (2) Sophisticated hands-on simulators that challenge the trainees to practice correct grip of the transducer, elucidate pathology, and practice daily tasks such as biometric measurements and analysis of sonographic data. (3) Participation in a video-taped simulation which focuses on physician-patient communications. In the simulation, the physician is required to diagnose the clinical condition of a hired actress based on the data she provides and by evaluating the assigned ultrasound films accordingly. Giving ‘bad news’ to the patient may put the physician in a stressful situation that must be properly managed. (4) Feedback at the end of each phase is provided by a designated trainer, not a physician, who is specially qualified by Ob\Gyn senior specialists. (5) A group exercise in which the trainer presents a medico-legal case in order to encourage the participants to use their own experience and knowledge to conduct a productive ‘brainstorming’ session. Medical cases are presented and analyzed by the participants together with the trainer's feedback. Findings: (1) The training methods and content that Simultech provides allows trainees to review their medical and communications skills. (2) Simultech training sessions expose physicians to both basic and new, up-to-date cases, refreshing and expanding the trainee's knowledge. (3) Practicing on advanced simulators enables trainees to understand the sonographic space and to implement the basic principles of ultrasound. (4) Communications simulations were found to be beneficial for trainees who were unaware of their interpersonal skills. The trainer feedback, supported by the recorded simulation, allows the trainee to draw conclusions about his performance. Conclusion: Simultech was found to contribute to physicians at all levels of clinical expertise who deal with ultrasound. A break in daily routine together with attendance at a neutral educational center can vastly improve performance and outlook.

Keywords: medical training, simulations, ultrasound, Simultech

Procedia PDF Downloads 256
285 Ultrasound Disintegration as a Potential Method for the Pre-Treatment of Virginia Fanpetals (Sida hermaphrodita) Biomass before Methane Fermentation Process

Authors: Marcin Dębowski, Marcin Zieliński, Mirosław Krzemieniewski

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As methane fermentation is a complex series of successive biochemical transformations, its subsequent stages are determined, to a various extent, by physical and chemical factors. A specific state of equilibrium is being settled in the functioning fermentation system between environmental conditions and the rate of biochemical reactions and products of successive transformations. In the case of physical factors that influence the effectiveness of methane fermentation transformations, the key significance is ascribed to temperature and intensity of biomass agitation. Among the chemical factors, significant are pH value, type, and availability of the culture medium (to put it simply: the C/N ratio) as well as the presence of toxic substances. One of the important elements which influence the effectiveness of methane fermentation is the pre-treatment of organic substrates and the mode in which the organic matter is made available to anaerobes. Out of all known and described methods for organic substrate pre-treatment before methane fermentation process, the ultrasound disintegration is one of the most interesting technologies. Investigations undertaken on the ultrasound field and the use of installations operating on the existing systems result principally from very wide and universal technological possibilities offered by the sonication process. This physical factor may induce deep physicochemical changes in ultrasonicated substrates that are highly beneficial from the viewpoint of methane fermentation processes. In this case, special role is ascribed to disintegration of biomass that is further subjected to methane fermentation. Once cell walls are damaged, cytoplasm and cellular enzymes are released. The released substances – either in dissolved or colloidal form – are immediately available to anaerobic bacteria for biodegradation. To ensure the maximal release of organic matter from dead biomass cells, disintegration processes are aimed to achieve particle size below 50 μm. It has been demonstrated in many research works and in systems operating in the technical scale that immediately after substrate supersonication the content of organic matter (characterized by COD, BOD5 and TOC indices) was increasing in the dissolved phase of sedimentation water. This phenomenon points to the immediate sonolysis of solid substances contained in the biomass and to the release of cell material, and consequently to the intensification of the hydrolytic phase of fermentation. It results in a significant reduction of fermentation time and increased effectiveness of production of gaseous metabolites of anaerobic bacteria. Because disintegration of Virginia fanpetals biomass via ultrasounds applied in order to intensify its conversion is a novel technique, it is often underestimated by exploiters of agri-biogas works. It has, however, many advantages that have a direct impact on its technological and economical superiority over thus far applied methods of biomass conversion. As for now, ultrasound disintegrators for biomass conversion are not produced on the mass-scale, but by specialized groups in scientific or R&D centers. Therefore, their quality and effectiveness are to a large extent determined by their manufacturers’ knowledge and skills in the fields of acoustics and electronic engineering.

Keywords: ultrasound disintegration, biomass, methane fermentation, biogas, Virginia fanpetals

Procedia PDF Downloads 354
284 Sustainable Marine Tourism: Opinion and Segmentation of Italian Generation Z

Authors: M. Bredice, M. B. Forleo, L. Quici

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Coastal tourism is currently facing huge challenges on how to balance environmental problems and tourist activities. Recent literature shows a growing interest in the issue of sustainable tourism from a so-called civilized tourists’ perspective by investigating opinions, perceptions, and behaviors. This study investigates the opinions of youth on what makes them responsible tourists and the ability of coastal marine areas to support tourism in future scenarios. A sample of 778 Italians attending the last year of high school was interviewed. Descriptive statistics, tests, and cluster analyses are applied to highlight the distribution of opinions among youth, detect significant differences based on demographic characteristics, and make segmentation of the different profiles based on students’ opinions and behaviors. Preliminary results show that students are largely convinced (62%) that by 2050 the quality of coastal environments could limit seaside tourism, while 10% of them believe that the problem can be solved simply by changing the tourist destination. Besides the cost of the holiday, the most relevant aspect respondents consider when choosing a marine destination is the presence of tourist attractions followed by the quality of the marine-coastal environment, the specificity of the local gastronomy and cultural traditions, and finally, the activities offered to guests such as sports and events. The reduction of waste and lower air emissions are considered the most important environmental areas in which marine-coastal tourism activities can contribute to preserving the quality of seas and coasts. Areas in which, as a tourist, they believe possible to give a personal contribution were (responses “very much” and “somewhat”); do not throw litter in the sea and on the beach (84%), do not buy single-use plastic products (66%), do not use soap or shampoo when showering in beaches (53%), do not have bonfires (47%), do not damage dunes (46%), and do not remove natural materials (e.g., sand, shells) from the beach (46%). About 6% of the sample stated that they were not interested in contributing to the aforementioned activities, while another 7% replied that they could not contribute at all. Finally, 80% of the sample has never participated in voluntary environmental initiatives or citizen science projects; moreover, about 64% of the students have never participated in events organized by environmental associations in marine or coastal areas. Regarding the test analysis -based on Kruskal-Wallis and Mann and Whitney tests - gender, region, and studying area of students reveals significance in terms of variables expressing knowledge and interest in sustainability topics and sustainable tourism behaviors. The classification of the education field is significant for a great number of variables, among which those related to several sustainable behaviors that respondents declare to be able to contribute as tourists. The ongoing cluster analysis will reveal different profiles in the sample and relevant variables. Based on preliminary results, implications are envisaged in the fields of education, policy, and business strategies for sustainable scenarios. Under these perspectives, the study has the potential to contribute to the conference debate about marine and coastal sustainable development and management.

Keywords: cluster analysis, education, knowledge, young people

Procedia PDF Downloads 62
283 Lifting Body Concepts for Unmanned Fixed-Wing Transport Aircrafts

Authors: Anand R. Nair, Markus Trenker

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Lifting body concepts were conceived as early as 1917 and patented by Roy Scroggs. It was an idea of using the fuselage as a lift producing body with no or small wings. Many of these designs were developed and even flight tested between 1920’s to 1970’s, but it was not pursued further for commercial flight as at lower airspeeds, such a configuration was incapable to produce sufficient lift for the entire aircraft. The concept presented in this contribution is combining the lifting body design along with a fixed wing to maximise the lift produced by the aircraft. Conventional aircraft fuselages are designed to be aerodynamically efficient, which is to minimise the drag; however, these fuselages produce very minimal or negligible lift. For the design of an unmanned fixed wing transport aircraft, many of the restrictions which are present for commercial aircraft in terms of fuselage design can be excluded, such as windows for the passengers/pilots, cabin-environment systems, emergency exits, and pressurization systems. This gives new flexibility to design fuselages which are unconventionally shaped to contribute to the lift of the aircraft. The two lifting body concepts presented in this contribution are targeting different applications: For a fast cargo delivery drone, the fuselage is based on a scaled airfoil shape with a cargo capacity of 500 kg for euro pallets. The aircraft has a span of 14 m and reaches 1500 km at a cruising speed of 90 m/s. The aircraft could also easily be adapted to accommodate pilot and passengers with modifications to the internal structures, but pressurization is not included as the service ceiling envisioned for this type of aircraft is limited to 10,000 ft. The next concept to be investigated is called a multi-purpose drone, which incorporates a different type of lifting body and is a much more versatile aircraft as it will have a VTOL capability. The aircraft will have a wingspan of approximately 6 m and flight speeds of 60 m/s within the same service ceiling as the fast cargo delivery drone. The multi-purpose drone can be easily adapted for various applications such as firefighting, agricultural purposes, surveillance, and even passenger transport. Lifting body designs are not a new concept, but their effectiveness in terms of cargo transportation has not been widely investigated. Due to their enhanced lift producing capability, lifting body designs enable the reduction of the wing area and the overall weight of the aircraft. This will, in turn, reduce the thrust requirement and ultimately the fuel consumption. The various designs proposed in this contribution will be based on the general aviation category of aircrafts and will be focussed on unmanned methods of operation. These unmanned fixed-wing transport drones will feature appropriate cargo loading/unloading concepts which can accommodate large size cargo for efficient time management and ease of operation. The various designs will be compared in performance to their conventional counterpart to understand their benefits/shortcomings in terms of design, performance, complexity, and ease of operation. The majority of the performance analysis will be carried out using industry relevant standards in computational fluid dynamics software packages.

Keywords: lifting body concept, computational fluid dynamics, unmanned fixed-wing aircraft, cargo drone

Procedia PDF Downloads 220
282 Unravelling Glyphosates Disruptive Effects on the Photochemical Efficiency of Amaranthus cruentus

Authors: Jacques M. Berner, Lehlogonolo Maloma

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Context: Glyphosate, a widely used herbicide, has raised concerns about its impact on various crops. Amaranthus cruentus, an important grain crop species, is particularly susceptible to glyphosate. Understanding the specific disruptions caused by glyphosate on the photosynthetic process in Amaranthus cruentus is crucial for assessing its effects on crop productivity and ecological sustainability. Research Aim: This study aimed to investigate the dose-dependent impact of glyphosate on the photochemical efficiency of Amaranthus cruentus using the OJIP transient analysis. The goal was to assess the specific disruptions caused by glyphosate on key parameters of photosystem II. Methodology: The experiment was conducted in a controlled greenhouse environment. Amaranthus cruentus plants were exposed to different concentrations of glyphosate, including half, recommended, and double the recommended application rates. The photochemical efficiency of the plants was evaluated using non-invasive chlorophyll a fluorescence measurements and subsequent analysis of OJIP transients. Measurements were taken on 1-hour dark-adapted leaves using a Hansatech Handy PEA+ chlorophyll fluorimeter. Findings: The study's results demonstrated a significant reduction in the photochemical efficiency of Amaranthus cruentus following glyphosate treatment. The OJIP transients showed distinct alterations in the glyphosate-treated plants compared to the control group. These changes included a decrease in maximal fluorescence (FP) and a delay in the rise of the fluorescence signal, indicating impairment in the energy conversion process within the photosystem II. Glyphosate exposure also led to a substantial decrease in the maximum quantum yield efficiency of photosystem II (FV/FM) and the total performance index (PItotal), which reflects the overall photochemical efficiency of photosystem II. These reductions in photochemical efficiency were observed even at half the recommended dose of glyphosate. Theoretical Importance: The study provides valuable insights into the specific disruptions caused by glyphosate on the photochemical efficiency of Amaranthus cruentus. Data Collection and Analysis Procedures: Data collection involved non-invasive chlorophyll a fluorescence measurements using a chlorophyll fluorimeter on dark-adapted leaves. The OJIP transients were then analyzed to assess specific disruptions in key parameters of photosystem II. Statistical analysis was conducted to determine the significance of the differences observed between glyphosate-treated plants and the control group. Question Addressed: The study aimed to address the question of how glyphosate exposure affects the photochemical efficiency of Amaranthus cruentus, specifically examining disruptions in the photosynthetic electron transport chain and overall photochemical efficiency. Conclusion: The study demonstrates that glyphosate severely impairs the photochemical efficiency of Amaranthus cruentus, as indicated by the alterations in OJIP transients. Even at half the recommended dose, glyphosate caused significant reductions in photochemical efficiency. These findings highlight the detrimental effects of glyphosate on crop productivity and emphasize the need for further research to evaluate its long-term consequences and ecological implications in agriculture. The authors gratefully acknowledge the support from North-West University for making this research possible.

Keywords: glyphosate, amaranthus cruentus, ojip transient analysis, pitotal, photochemical efficiency, chlorophyll fluorescence, weeds

Procedia PDF Downloads 73
281 Pluripotent Stem Cells as Therapeutic Tools for Limbal Stem Cell Deficiencies and Drug Testing

Authors: Aberdam Edith, Sangari Linda, Petit Isabelle, Aberdam Daniel

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Background and Rationale: Transparent avascularised cornea is essential for normal vision and depends on limbal stem cells (LSC) that reside between the cornea and the conjunctiva. Ocular burns or injuries may destroy the limbus, causing limbal stem cell deficiency (LSCD). The cornea becomes vascularised by invaded conjunctival cells, the stroma is scarring, resulting in corneal opacity and loss of vision. Grafted autologous limbus or cultivated autologous LCS can restore the vision, unless the two eyes are affected. Alternative cellular sources have been tested in the last decades, including oral mucosa or hair follicle epithelial cells. However, only partial success has been achieved by the use of these cells since they were not able to uniformly commit into corneal epithelial cells. Human pluripotent stem cells (iPSC) display both unlimited growth capacity and ability to differentiate into any cell type. Our goal was to design a standardized and reproducible protocol to produce transplantable autologous LSC from patients through cell reprogramming technology. Methodology: First, keratinocyte primary culture was established from a small number of plucked hair follicles of healthy donors. The resulting epithelial cells were reprogrammed into induced pluripotent stem cells (iPSCs) and further differentiate into corneal epithelial cells (CEC), according to a robust protocol that recapitulates the main step of corneal embryonic development. qRT-PCR analysis and immunofluorescent staining during the course of differentiation confirm the expression of stage specific markers of corneal embryonic lineage. First appear ectodermal progenitor-specific cytokeratins K8/K18, followed at day 7 by limbal-specific PAX6, TP63 and cytokeratins K5/K14. At day 15, K3/K12+-corneal cells are present. To amplify the iPSC-derived LSC (named COiPSC), intact small epithelial colonies were detached and cultivated in limbal cell-specific medium. In that culture conditions, the COiPSC can be frozen and thaw at any passage, while retaining their corneal characteristics for at least eight passages. To evaluate the potential of COiPSC as an alternative ocular toxicity model, COiPSC were treated at passage P0 to P4 with increasing amounts of SDS and Benzalkonium. Cell proliferation and apoptosis of treated cells was compared to LSC and the SV40-immortalized human corneal epithelial cell line (HCE) routinely used by cosmetological industrials. Of note, HCE are more resistant to toxicity than LSC. At P0, COiPSC were systematically more resistant to chemical toxicity than LSC and even to HCE. Remarkably, this behavior changed with passage since COiPSC at P2 became identical to LSC and thus closer to physiology than HCE. Comparative transcriptome analysis confirmed that COiPSC from P2 are similar to a mixture of LSC and CEC. Finally, by organotypic reconstitution assay, we demonstrated the ability of COiPSC to produce a 3D corneal epithelium on a stromal equivalent made of keratocytes. Conclusion: COiPSC could become valuable for two main applications: (1) an alternative robust tool to perform, in a reproducible and physiological manner, toxicity assays for cosmetic products and pharmacological tests of drugs. (2). COiPSC could become an alternative autologous source for cornea transplantation for LSCD.

Keywords: Limbal stem cell deficiency, iPSC, cornea, limbal stem cells

Procedia PDF Downloads 394
280 Optical-Based Lane-Assist System for Rowing Boats

Authors: Stephen Tullis, M. David DiDonato, Hong Sung Park

Abstract:

Rowing boats (shells) are often steered by a small rudder operated by one of the backward-facing rowers; the attention required of that athlete then slightly decreases the power that that athlete can provide. Reducing the steering distraction would then increase the overall boat speed. Races are straight 2000 m courses with each boat in a 13.5 m wide lane marked by small (~15 cm) widely-spaced (~10 m) buoys, and the boat trajectory is affected by both cross-currents and winds. An optical buoy recognition and tracking system has been developed that provides the boat’s location and orientation with respect to the lane edges. This information is provided to the steering athlete as either: a simple overlay on a video display, or fed to a simplified autopilot system giving steering directions to the athlete or directly controlling the rudder. The system is then effectively a “lane-assist” device but with small, widely-spaced lane markers viewed from a very shallow angle due to constraints on camera height. The image is captured with a lightweight 1080p webcam, and most of the image analysis is done in OpenCV. The colour RGB-image is converted to a grayscale using the difference of the red and blue channels, which provides good contrast between the red/yellow buoys and the water, sky, land background and white reflections and noise. Buoy detection is done with thresholding within a tight mask applied to the image. Robust linear regression using Tukey’s biweight estimator of the previously detected buoy locations is used to develop the mask; this avoids the false detection of noise such as waves (reflections) and, in particular, buoys in other lanes. The robust regression also provides the current lane edges in the camera frame that are used to calculate the displacement of the boat from the lane centre (lane location), and its yaw angle. The interception of the detected lane edges provides a lane vanishing point, and yaw angle can be calculated simply based on the displacement of this vanishing point from the camera axis and the image plane distance. Lane location is simply based on the lateral displacement of the vanishing point from any horizontal cut through the lane edges. The boat lane position and yaw are currently fed what is essentially a stripped down marine auto-pilot system. Currently, only the lane location is used in a PID controller of a rudder actuator with integrator anti-windup to deal with saturation of the rudder angle. Low Kp and Kd values decrease unnecessarily fast return to lane centrelines and response to noise, and limiters can be used to avoid lane departure and disqualification. Yaw is not used as a control input, as cross-winds and currents can cause a straight course with considerable yaw or crab angle. Mapping of the controller with rudder angle “overall effectiveness” has not been finalized - very large rudder angles stall and have decreased turning moments, but at less extreme angles the increased rudder drag slows the boat and upsets boat balance. The full system has many features similar to automotive lane-assist systems, but with the added constraints of the lane markers, camera positioning, control response and noise increasing the challenge.

Keywords: auto-pilot, lane-assist, marine, optical, rowing

Procedia PDF Downloads 116
279 The Istrian Istrovenetian-Croatian Bilingual Corpus

Authors: Nada Poropat Jeletic, Gordana Hrzica

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Bilingual conversational corpora represent a meaningful and the most comprehensive data source for investigating the genuine contact phenomena in non-monitored bi-lingual speech productions. They can be particularly useful for bilingual research since some features of bilingual interaction can hardly be accessed with more traditional methodologies (e.g., elicitation tasks). The method of language sampling provides the resources for describing language interaction in a bilingual community and/or in bilingual situations (e.g. code-switching, amount of languages used, number of languages used, etc.). To capture these phenomena in genuine communication situations, such sampling should be as close as possible to spontaneous communication. Bilingual spoken corpus design is methodologically demanding. Therefore this paper aims at describing the methodological challenges that apply to the corpus design of the conversational corpus design of the Istrian Istrovenetian-Croatian Bilingual Corpus. Croatian is the first official language of the Croatian-Italian officially bilingual Istria County, while Istrovenetian is a diatopic subvariety of Venetian, a longlasting lingua franca in the Istrian peninsula, the mother tongue of the members of the Italian National Community in Istria and the primary code of informal everyday communication among the Istrian Italophone population. Within the CLARIN infrastructure, TalkBank is being used, as it provides relevant procedures for designing and analyzing bilingual corpora. Furthermore, it allows public availability allows for easy replication of studies and cumulative progress as a research community builds up around the corpus, while the tools developed within the field of corpus linguistics enable easy retrieval and analysis of information. The method of language sampling employed is kept at the level of spontaneous communication, in order to maximise the naturalness of the collected conversational data. All speakers have provided written informed consent in which they agree to be recorded at a random point within the period of one month after signing the consent. Participants are administered a background questionnaire providing information about the socioeconomic status and the exposure and language usage in the participants social networks. Recording data are being transcribed, phonologically adapted within a standard-sized orthographic form, coded and segmented (speech streams are being segmented into communication units based on syntactic criteria) and are being marked following the CHAT transcription system and its associated CLAN suite of programmes within the TalkBank toolkit. The corpus consists of transcribed sound recordings of 36 bilingual speakers, while the target is to publish the whole corpus by the end of 2020, by sampling spontaneous conversations among approximately 100 speakers from all the bilingual areas of Istria for ensuring representativeness (the participants are being recruited across three generations of native bilingual speakers in all the bilingual areas of the peninsula). Conversational corpora are still rare in TalkBank, so the Corpus will contribute to BilingBank as a highly relevant and scientifically reliable resource for an internationally established and active research community. The impact of the research of communities with societal bilingualism will contribute to the growing body of research on bilingualism and multilingualism, especially regarding topics of language dominance, language attrition and loss, interference and code-switching etc.

Keywords: conversational corpora, bilingual corpora, code-switching, language sampling, corpus design methodology

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278 Distribution System Modelling: A Holistic Approach for Harmonic Studies

Authors: Stanislav Babaev, Vladimir Cuk, Sjef Cobben, Jan Desmet

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The procedures for performing harmonic studies for medium-voltage distribution feeders have become relatively mature topics since the early 1980s. The efforts of various electric power engineers and researchers were mainly focused on handling large harmonic non-linear loads connected scarcely at several buses of medium-voltage feeders. In order to assess the impact of these loads on the voltage quality of the distribution system, specific modeling and simulation strategies were proposed. These methodologies could deliver a reasonable estimation accuracy given the requirements of least computational efforts and reduced complexity. To uphold these requirements, certain analysis assumptions have been made, which became de facto standards for establishing guidelines for harmonic analysis. Among others, typical assumptions include balanced conditions of the study and the negligible impact of impedance frequency characteristics of various power system components. In latter, skin and proximity effects are usually omitted, and resistance and reactance values are modeled based on the theoretical equations. Further, the simplifications of the modelling routine have led to the commonly accepted practice of neglecting phase angle diversity effects. This is mainly associated with developed load models, which only in a handful of cases are representing the complete harmonic behavior of a certain device as well as accounting on the harmonic interaction between grid harmonic voltages and harmonic currents. While these modelling practices were proven to be reasonably effective for medium-voltage levels, similar approaches have been adopted for low-voltage distribution systems. Given modern conditions and massive increase in usage of residential electronic devices, recent and ongoing boom of electric vehicles, and large-scale installing of distributed solar power, the harmonics in current low-voltage grids are characterized by high degree of variability and demonstrate sufficient diversity leading to a certain level of cancellation effects. It is obvious, that new modelling algorithms overcoming previously made assumptions have to be accepted. In this work, a simulation approach aimed to deal with some of the typical assumptions is proposed. A practical low-voltage feeder is modeled in PowerFactory. In order to demonstrate the importance of diversity effect and harmonic interaction, previously developed measurement-based models of photovoltaic inverter and battery charger are used as loads. The Python-based script aiming to supply varying voltage background distortion profile and the associated current harmonic response of loads is used as the core of unbalanced simulation. Furthermore, the impact of uncertainty of feeder frequency-impedance characteristics on total harmonic distortion levels is shown along with scenarios involving linear resistive loads, which further alter the impedance of the system. The comparative analysis demonstrates sufficient differences with cases when all the assumptions are in place, and results indicate that new modelling and simulation procedures need to be adopted for low-voltage distribution systems with high penetration of non-linear loads and renewable generation.

Keywords: electric power system, harmonic distortion, power quality, public low-voltage network, harmonic modelling

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277 Strategies for Urban-Architectural Design for the Sustainable Recovery of the Huayla Stuary in Puerto Bolivar, Machala-Ecuador

Authors: Soledad Coronel Poma, Lorena Alvarado Rodriguez

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The purpose of this project is to design public space through urban-architectural strategies that help to the sustainable recovery of the Huayla estuary and the revival of tourism in this area. This design considers other sustainable and architectural ideas used in similar cases, along with national and international regulations for saving shorelines in danger. To understand the situation of this location, Puerto Bolivar is the main port of the Province of El Oro and of the south of the country, where 90,000 national and foreign tourists pass through all year round. For that reason, a physical-urban, social, and environmental analysis of the area was carried out through surveys and conversations with the community. This analysis showed that around 70% of people feel unsatisfied and concerned about the estuary and its surroundings. Crime, absence of green areas, bad conservation of shorelines, lack of tourists, poor commercial infrastructure, and the spread of informal commerce are the main issues to be solved. As an intervention project whose main goal is that residents and tourists have contact with native nature and enjoy doing local activities, three main strategies: mobility, ecology, and urban –architectural are proposed to recover the estuary and its surroundings. First of all, the design of this public space is based on turning the estuary location into a linear promenade that could be seen as a tourist corridor, which would help to reduce pollution, increase green spaces and improve tourism. Another strategy aims to improve the economy of the community through some local activities like fishing and sailing and the commerce of fresh seafood, both raw products and in restaurants. Furthermore, in support of the environmental approach, some houses are rebuilt as sustainable houses using local materials and rearranged into blocks closer to the commercial area. Finally, the planning incorporates the use of many plants such as palms, sameness trees, and mangroves around the area to encourage people to get in touch with nature. The results of designing this space showed an increase in the green area per inhabitant index. It went from 1.69 m²/room to 10.48 m²/room, with 12 096 m² of green corridors and the incorporation of 5000 m² of mangroves at the shoreline. Additionally, living zones also increased with the creation of green areas taking advantage of the existing nature and implementing restaurants and recreational spaces. Moreover, the relocation of houses and buildings helped to free estuary's shoreline, so people are now in more comfortable places closer to their workplaces. Finally, dock spaces are increased, reaching the capacity of the boats and canoes, helping to organize the area in the estuary. To sum up, this project searches the improvement of the estuary environment with its shoreline and surroundings that include the vegetation, infrastructure and people with their local activities, achieving a better quality of life, attraction of tourism, reduction of pollution and finally getting a full recovered estuary as a natural ecosystem.

Keywords: recover, public space, stuary, sustainable

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276 Endometrial Ablation and Resection Versus Hysterectomy for Heavy Menstrual Bleeding: A Systematic Review and Meta-Analysis of Effectiveness and Complications

Authors: Iliana Georganta, Clare Deehan, Marysia Thomson, Miriam McDonald, Kerrie McNulty, Anna Strachan, Elizabeth Anderson, Alyaa Mostafa

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Context: A meta-analysis of randomized controlled trials (RCTs) comparing hysterectomy versus endometrial ablation and resection in the management of heavy menstrual bleeding. Objective: To evaluate the clinical efficacy, satisfaction rates and adverse events of hysterectomy compared to more minimally invasive techniques in the treatment of HMB. Evidence Acquisition: A literature search was performed for all RCTs and quasi-RCTs comparing hysterectomy with either endometrial ablation endometrial resection of both. The search had no language restrictions and was last updated in June 2020 using MEDLINE, EMBASE, Cochrane Central Register of Clinical Trials, PubMed, Google Scholar, PsycINFO, Clinicaltrials.gov and Clinical trials. EU. In addition, a manual search of the abstract databases of the European Haemophilia Conference on women's health was performed and further studies were identified from references of acquired papers. The primary outcomes were patient-reported and objective reduction in heavy menstrual bleeding up to 2 years and after 2 years. Secondary outcomes included satisfaction rates, pain, adverse events short and long term, quality of life and sexual function, further surgery, duration of surgery and hospital stay and time to return to work and normal activities. Data were analysed using RevMan software. Evidence synthesis: 12 studies and a total of 2028 women were included (hysterectomy: n = 977 women vs endometrial ablation or resection: n = 1051 women). Hysterectomy was compared with endometrial ablation only in five studies (Lin, Dickersin, Sesti, Jain, Cooper) and endometrial resection only in five studies (Gannon, Schulpher, O’Connor, Crosignani, Zupi) and a mixture of the Ablation and Resection in two studies (Elmantwe, Pinion). Of the 1² studies, 10 reported women’s perception of bleeding symptoms as improved. Meta-analysis showed that women in the hysterectomy group were more likely to show improvement in bleeding symptoms when compared with endometrial ablation or resection up to 2-year follow-up (RR 0.75, 95% CI 0.71 to 0.79, I² = 95%). Objective outcomes of improvement in bleeding also favored hysterectomy. Patient satisfaction was higher after hysterectomy within the 2 years follow-up (RR: 0.90, 95%CI: 0.86 to 0.94, I²:58%), however, there was no significant difference between the two groups at more than 2 years follow up. Sepsis (RR: 0.03, 95% CI 0.002 to 0.56; 1 study), wound infection (RR: 0.05, 95% CI: 0.01 to 0.28, I²: 0%, 3 studies) and Urinary tract infection (UTI) (RR: 0.20, 95% CI: 0.10 to 0.42, I²: 0%, 4 studies) all favoured hysteroscopic techniques. Fluid overload (RR: 7.80, 95% CI: 2.16 to 28.16, I² :0%, 4 studies) and perforation (RR: 5.42, 95% CI: 1.25 to 23.45, I²: 0%, 4 studies) however favoured hysterectomy in the short term. Conclusions: This meta-analysis has demonstrated that endometrial ablation and endometrial resection are both viable options when compared with hysterectomy for the treatment of heavy menstrual bleeding. Hysteroscopic procedures had better outcomes in the short term with fewer adverse events including wound infection, UTI and sepsis. The hysterectomy performed better when measuring more long-term impacts such as recurrence of symptoms, overall satisfaction at two years and the need for further treatment or surgery.

Keywords: menorrhagia, hysterectomy, ablation, resection

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275 Virulence Factors and Drug Resistance of Enterococci Species Isolated from the Intensive Care Units of Assiut University Hospitals, Egypt

Authors: Nahla Elsherbiny, Ahmed Ahmed, Hamada Mohammed, Mohamed Ali

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Background: The enterococci may be considered as opportunistic agents particularly in immunocompromised patients. It is one of the top three pathogens causing many healthcare associated infections (HAIs). Resistance to several commonly used antimicrobial agents is a remarkable characteristic of most species which may carry various genes contributing to virulence. Objectives: to determine the prevalence of enterococci species in different intensive care units (ICUs) causing health care-associated infections (HAIs), intestinal carriage and environmental contamination. Also, to study the antimicrobial susceptibility pattern of the isolates with special reference to vancomycin resistance. In addition to phenotypic and genotypic detection of gelatinase, cytolysin and biofilm formation among isolates. Patients and Methods: This study was carried out in the infection control laboratory at Assiut University Hospitals over a period of one year. Clinical samples were collected from 285 patients with various (HAIs) acquired after admission to different ICUs. Rectal swabs were taken from 14 cases for detection of enterococci carriage. In addition, 1377 environmental samples were collected from the surroundings of the patients. Identification was done by conventional bacteriological methods and confirmed by analytical profile index (API). Antimicrobial sensitivity testing was performed by Kirby Bauer disc diffusion method and detection of vancomycin resistance was done by agar screen method. For the isolates, phenotypic detection of cytolysin, gelatinase production and detection of biofilm by tube method, Congo red method and microtiter plate. We performed polymerase chain reaction (PCR) for detection of some virulence genes (gelE, cylA, vanA, vanB and esp). Results: Enterococci caused 10.5% of the HAIs. Respiratory tract infection was the predominant type (86.7%). The commonest species were E.gallinarum (36.7%), E.casseliflavus (30%), E.faecalis (30%), and E.durans (3.4 %). Vancomycin resistance was detected in a total of 40% (12/30) of those isolates. The risk factors associated with acquiring vancomycin resistant enterococci (VRE) were immune suppression (P= 0.031) and artificial feeding (P= 0.008). For the rectal swabs, enterococci species were detected in 71.4% of samples with the predominance of E. casseliflavus (50%). Most of the isolates were vancomycin resistant (70%). Out of a total 1377 environmental samples, 577 (42%) samples were contaminated with different microorganisms. Enterococci were detected in 1.7% (10/577) of total contaminated samples, 50% of which were vancomycin resistant. All isolates were resistant to penicillin, ampicillin, oxacillin, ciprofloxacin, amikacin, erythromycin, clindamycin and trimethoprim-sulfamethaxazole. For the remaining antibiotics, variable percentages of resistance were reported. Cytolysin and gelatinase were detected phenotypically in 16% and 48 % of the isolates respectively. The microtiter plate method showed the highest percentages of detection of biofilm among all isolated species (100%). The studied virulence genes gelE, esp, vanA and vanB were detected in 62%, 12%, 2% and 12% respectively, while cylA gene was not detected in any isolates. Conclusions: A significant percentage of enterococci was isolated from patients and environments in the ICUs. Many virulence factors were detected phenotypically and genotypically among isolates. The high percentage of resistance, coupled with the risk of cross transmission to other patients make enterococci infections a significant infection control issue in hospitals.

Keywords: antimicrobial resistance, enterococci, ICUs, virulence factors

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274 Health Equity in Hard-to-Reach Rural Communities in Abia State, Nigeria: An Asset-Based Community Development Intervention to Influence Community Norms and Address the Social Determinants of Health in Hard-to-Reach Rural Communities

Authors: Chinasa U. Imo, Queen Chikwendu, Jonathan Ajuma, Mario Banuelos

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Background: Sociocultural norms primarily influence the health-seeking behavior of populations in rural communities. In the Nkporo community, Abia State, Nigeria, their sociocultural perception of diseases runs counter to biomedical definitions, wherein they rely heavily on traditional medicine and practices. In a state where birth asphyxia and sepsis account for the significant causes of death for neonates, malaria leads to the causes of other mortalities, followed by common preventable diseases such as diarrhea, pneumonia, acute respiratory tract infection, malnutrition, and HIV/AIDS. Most local mothers attribute their health conditions and that of their children to witchcraft attacks, the hand of God, and ancestral underlining. This influences how they see antenatal and postnatal care, choice of place of accessing care and birth delivery, response to children's illnesses, immunization, and nutrition. Method: To implement a community health improvement program, we adopted an asset-based community development model to address health's normative and social determinants. The first step was to use a qualitative approach to conduct a community health needs baseline assessment, involving focus group discussions with twenty-five (25) youths aged 18-25, semi-structured interviews with ten (10) officers-in-charge of primary health centers, eight (8) ward health committee members, and nine (9) community leaders. Secondly, we designed an intervention program. Going forward, we will proceed with implementing and evaluating this program. Result: The priority needs identified by the communities were malaria, lack of clean drinking water, and the need for behavioral change information. The study also highlighted the significant influence of youths on their peers, family, and community as caregivers and information interpreters. Based on the findings, the NGO SieDi-Hub collaborated with the Abia State Ministry of Health, the State Primary Healthcare Agency, and Empower Next Generations to design a one-year "Community Health Youth Champions Pilot Program." Twenty (20) youths in the community were trained and equipped to champion a participatory approach to bridging the gap between access and delivery of primary healthcare, to adjust sociocultural norms to improve health equity for people in Nkporo community – with limited education, lack of access to health information, and quality healthcare facilities using an innovative community-led improvement approach. Conclusion: Youths play a vital role in achieving health equity, being a vulnerable population with significant influence. To ensure effective primary healthcare, strategies must include cultural humility. The asset-based community development model offers valuable tools, and this article will share ongoing lessons from the intervention's behavioral change strategies with young people.

Keywords: asset-based community development, community health, primary health systems strengthening, youth empowerment

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273 Synthesis of Smart Materials Based on Polyaniline Coated Fibers

Authors: Mihaela Beregoi, Horia Iovu, Cristina Busuioc, Alexandru Evanghelidis, Elena Matei, Monica Enculescu, Ionut Enculescu

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Nanomaterials field is very attractive for all researchers who are attempting to develop new devices with the same or improved properties than the micro-sized ones, while reducing the reagents and power consumptions. In this way, a wide range of nanomaterials were fabricated and integrated in applications for electronics, optoelectronics, solar cells, tissue reconstruction and drug delivery. Obviously, the most appealing ones are those dedicated to the medical domain. Different types of nano-sized materials, such as particles, fibers, films etc., can be synthesized by using physical, chemical or electrochemical methods. One of these techniques is electrospinning, which enable the production of fibers with nanometric dimensions by pumping a polymeric solution in a high electric field; due to the electrostatic charging and solvent evaporation, the precursor mixture is converted into nonwoven meshes with different fiber densities and mechanical properties. Moreover, polyaniline is a conducting polymer with interesting optical properties, suitable for displays and electrochromic windows. Otherwise, polyaniline is an electroactive polymer that can contract/expand by applying electric stimuli, due to the oxidation/reduction reactions which take place in the polymer chains. These two main properties can be exploited in order to synthesize smart materials that change their dimensions, exhibiting in the same time good electrochromic properties. In the context aforesaid, a poly(methyl metacrylate) solution was spun to get webs composed of fibers with diameter values between 500 nm and 1 µm. Further, the polymer meshes were covered with a gold layer in order to make them conductive and also appropriate as working electrode in an electrochemical cell. The gold shell was deposited by DC sputtering. Such metalized fibers can be transformed into smart materials by covering them with a thin layer of conductive polymer. Thus, the webs were coated with a polyaniline film by the electrochemical route, starting from and aqueous solution of aniline and sulfuric acid, where sulfuric acid acts as oxidant agent. For the polymerization of aniline, a saturated calomel electrode was employed as reference, a platinum plate as counter electrode and the gold covered webs as working electrode. Chronoamperometry was selected as deposition method for polyaniline, by modifying the deposition time. Metalized meshes with different fiber densities were used, the transmission ranging between 70 and 80 %. The morphological investigation showed that polyaniline layer has a granular structure for all deposition experiments. As well, some preliminary optical tests were done by using sulfuric acid as electrolyte, which revealed the modification of polyaniline colour from green to dark blue when applying a voltage. In conclusion, new multilayered materials were obtained by a simple approach: the merge of the electrospinning method benefits with polyaniline chemistry. This synthesis method allows the fabrication of structures with reproducible characteristics, suitable for display or tissue substituents.

Keywords: electrospinning, fibers, smart materials, polyaniline

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272 Pricing Techniques to Mitigate Recurring Congestion on Interstate Facilities Using Dynamic Feedback Assignment

Authors: Hatem Abou-Senna

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Interstate 4 (I-4) is a primary east-west transportation corridor between Tampa and Daytona cities, serving commuters, commercial and recreational traffic. I-4 is known to have severe recurring congestion during peak hours. The congestion spans about 11 miles in the evening peak period in the central corridor area as it is considered the only non-tolled limited access facility connecting the Orlando Central Business District (CBD) and the tourist attractions area (Walt Disney World). Florida officials had been skeptical of tolling I-4 prior to the recent legislation, and the public through the media had been complaining about the excessive toll facilities in Central Florida. So, in search for plausible mitigation to the congestion on the I-4 corridor, this research is implemented to evaluate the effectiveness of different toll pricing alternatives that might divert traffic from I-4 to the toll facilities during the peak period. The network is composed of two main diverging limited access highways, freeway (I-4) and toll road (SR 417) in addition to two east-west parallel toll roads SR 408 and SR 528, intersecting the above-mentioned highways from both ends. I-4 and toll road SR 408 are the most frequently used route by commuters. SR-417 is a relatively uncongested toll road with 15 miles longer than I-4 and $5 tolls compared to no monetary cost on 1-4 for the same trip. The results of the calibrated Orlando PARAMICS network showed that percentages of route diversion vary from one route to another and depends primarily on the travel cost between specific origin-destination (O-D) pairs. Most drivers going from Disney (O1) or Lake Buena Vista (O2) to Lake Mary (D1) were found to have a high propensity towards using I-4, even when eliminating tolls and/or providing real-time information. However, a diversion from I-4 to SR 417 for these OD pairs occurred only in the cases of the incident and lane closure on I-4, due to the increase in delay and travel costs, and when information is provided to travelers. Furthermore, drivers that diverted from I-4 to SR 417 and SR 528 did not gain significant travel-time savings. This was attributed to the limited extra capacity of the alternative routes in the peak period and the longer traveling distance. When the remaining origin-destination pairs were analyzed, average travel time savings on I-4 ranged between 10 and 16% amounting to 10 minutes at the most with a 10% increase in the network average speed. High propensity of diversion on the network increased significantly when eliminating tolls on SR 417 and SR 528 while doubling the tolls on SR 408 along with the incident and lane closure scenarios on I-4 and with real-time information provided. The toll roads were found to be a viable alternative to I-4 for these specific OD pairs depending on the user perception of the toll cost which was reflected in their specific travel times. However, on the macroscopic level, it was concluded that route diversion through toll reduction or elimination on surrounding toll roads would only have a minimum impact on reducing I-4 congestion during the peak period.

Keywords: congestion pricing, dynamic feedback assignment, microsimulation, paramics, route diversion

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