Search results for: carrier agents
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2061

Search results for: carrier agents

981 A Comparative Analysis of Various Companding Techniques Used to Reduce PAPR in VLC Systems

Authors: Arushi Singh, Anjana Jain, Prakash Vyavahare

Abstract:

Recently, Li-Fi(light-fiedelity) has been launched based on VLC(visible light communication) technique, 100 times faster than WiFi. Now 5G mobile communication system is proposed to use VLC-OFDM as the transmission technique. The VLC system focused on visible rays, is considered for efficient spectrum use and easy intensity modulation through LEDs. The reason of high speed in VLC is LED, as they flicker incredibly fast(order of MHz). Another advantage of employing LED is-it acts as low pass filter results no out-of-band emission. The VLC system falls under the category of ‘green technology’ for utilizing LEDs. In present scenario, OFDM is used for high data-rates, interference immunity and high spectral efficiency. Inspite of the advantages OFDM suffers from large PAPR, ICI among carriers and frequency offset errors. Since, the data transmission technique used in VLC system is OFDM, the system suffers the drawbacks of OFDM as well as VLC, the non-linearity dues to non-linear characteristics of LED and PAPR of OFDM due to which the high power amplifier enters in non-linear region. The proposed paper focuses on reduction of PAPR in VLC-OFDM systems. Many techniques are applied to reduce PAPR such as-clipping-introduces distortion in the carrier; selective mapping technique-suffers wastage of bandwidth; partial transmit sequence-very complex due to exponentially increased number of sub-blocks. The paper discusses three companding techniques namely- µ-law, A-law and advance A-law companding technique. The analysis shows that the advance A-law companding techniques reduces the PAPR of the signal by adjusting the companding parameter within the range. VLC-OFDM systems are the future of the wireless communication but non-linearity in VLC-OFDM is a severe issue. The proposed paper discusses the techniques to reduce PAPR, one of the non-linearities of the system. The companding techniques mentioned in this paper provides better results without increasing the complexity of the system.

Keywords: non-linear companding techniques, peak to average power ratio (PAPR), visible light communication (VLC), VLC-OFDM

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980 Synthesis, Electrochemical and Fluorimetric Analysis of Caffeic Cinnamic and Acid-Conjugated Hemorphine Derivatives Designed as Potential Anticonvulsant Agents

Authors: Jana Tchekalarova, Stela Georgieva, Petia Peneva, Petar Todorov

Abstract:

In the present study, a series of bioconjugates of N-modified hemorphine analogs containing second pharmacophore cinnamic acids (CA) or caffeic acid (KA) were synthesized by a traditional solid-phase Fmoc chemistry method for peptide synthesis. Electrochemical and fluorometric analysis and in vivo anticonvulsant activity in mice were conducted on the compounds. The three CA (H4-CA, H5-CA, and H7-CA) and three KA (H4-KA, H5-KA, and H7-KA)-conjugated hemorphine derivatives showed dose-dependent anticonvulsant activity in the maximal electroshock test (MES) in mice. The KA-conjugated H5-KA derivate was the only compound that suppressed clonic seizures at the lowest dose of 0.5 µg/mouse in the scPTZ test. The activity against the psychomotor seizures in the 6-Hz test was detected only for the H4-CA (0.5 µg) and H4-KA (0.5 µg and 1 µg), respectively. The peptide derivates did not exhibit neurotoxicity in the rotarod test. Our findings suggest that conjugated CA and KA hemorphine peptides can be used as a background for developing hemorphin-related analogs with anticonvulsant activity. Acknowledgments: This study is funded by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project № BG-RRP-2.004-0002, "BiOrgaMCT".

Keywords: hemorphins, SPSS, caffeic/cinnamic acid, anticonvulsant activity, electrochemistry, fluorimetry

Procedia PDF Downloads 152
979 Policies for Circular Bioeconomy in Portugal: Barriers and Constraints

Authors: Ana Fonseca, Ana Gouveia, Edgar Ramalho, Rita Henriques, Filipa Figueiredo, João Nunes

Abstract:

Due to persistent climate pressures, there is a need to find a resilient economic system that is regenerative in nature. Bioeconomy offers the possibility of replacing non-renewable and non-biodegradable materials derived from fossil fuels with ones that are renewable and biodegradable, while a Circular Economy aims at sustainable and resource-efficient operations. The term "Circular Bioeconomy", which can be summarized as all activities that transform biomass for its use in various product streams, expresses the interaction between these two ideas. Portugal has a very favourable context to promote a Circular Bioeconomy due to its variety of climates and ecosystems, availability of biologically based resources, location, and geomorphology. Recently, there have been political and legislative efforts to develop the Portuguese Circular Bioeconomy. The Action Plan for a Sustainable Bioeconomy, approved in 2021, is composed of five axes of intervention, ranging from sustainable production and the use of regionally based biological resources to the development of a circular and sustainable bioindustry through research and innovation. However, as some statistics show, Portugal is still far from achieving circularity. According to Eurostat, Portugal has circularity rates of 2.8%, which is the second lowest among the member states of the European Union. Some challenges contribute to this scenario, including sectorial heterogeneity and fragmentation, prevalence of small producers, lack of attractiveness for younger generations, and absence of implementation of collaborative solutions amongst producers and along value chains.Regarding the Portuguese industrial sector, there is a tendency towards complex bureaucratic processes, which leads to economic and financial obstacles and an unclear national strategy. Together with the limited number of incentives the country has to offer to those that pretend to abandon the linear economic model, many entrepreneurs are hesitant to invest the capital needed to make their companies more circular. Absence of disaggregated, georeferenced, and reliable information regarding the actual availability of biological resources is also a major issue. Low literacy on bioeconomy among many of the sectoral agents and in society in general directly impacts the decisions of production and final consumption. The WinBio project seeks to outline a strategic approach for the management of weaknesses/opportunities in the technology transfer process, given the reality of the territory, through road mapping and national and international benchmarking. The developed work included the identification and analysis of agents in the interior region of Portugal, natural endogenous resources, products, and processes associated with potential development. Specific flow of biological wastes, possible value chains, and the potential for replacing critical raw materials with bio-based products was accessed, taking into consideration other countries with a matured bioeconomy. The study found food industry, agriculture, forestry, and fisheries generate huge amounts of waste streams, which in turn provide an opportunity for the establishment of local bio-industries powered by this biomass. The project identified biological resources with potential for replication and applicability in the Portuguese context. The richness of natural resources and potentials known in the interior region of Portugal is a major key to developing the Circular Economy and sustainability of the country.

Keywords: circular bioeconomy, interior region of portugal, regional development., public policy

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978 Formulation and Evaluation of Solid Dispersion of an Anti-Epileptic Drug Carbamazepine

Authors: Sharmin Akhter, M. Salahuddin, Sukalyan Kumar Kundu, Mohammad Fahim Kadir

Abstract:

Relatively insoluble candidate drug like carbamazepine (CBZ) often exhibit incomplete or erratic absorption; and hence wide consideration is given to improve aqueous solubility of such compound. Solid dispersions were formulated with an aim of improving aqueous solubility, oral bioavailability and the rate of dissolution of Carbamazepine using different hydrophyllic polymer like Polyethylene Glycol (PEG) 6000, Polyethylene Glycol (PEG) 4000, kollidon 30, HPMC 6 cps, poloxamer 407 and povidone k 30. Solid dispersions were prepared with different drug to polymer weight ratio by the solvent evaporation method where methanol was used as solvent. Drug-polymer physical mixtures were also prepared to compare the rate of dissolution. Effects of different polymer were studied for solid dispersion formulation as well as physical mixtures. These formulations were characterized in the solid state by Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). Solid state characterization indicated CBZ was present as fine particles and entrapped in carrier matrix of PEG 6000 and PVP K30 solid dispersions. Fourier Transform Infrared (FTIR) spectroscopic studies showed the stability of CBZ and absence of well-defined drug-polymer interactions. In contrast to the very slow dissolution rate of pure CBZ, dispersions of drug in polymers considerably improved the dissolution rate. This can be attributed to increased wettability and dispersibility, as well as decreased crystallinity and increase in amorphous fraction of drug. Solid dispersion formulations containing PEG 6000 and Povidone K 30 showed maximum drug release within one hour at the ratio of 1:1:1. Even physical mixtures of CBZ prepared with both carriers also showed better dissolution profiles than those of pure CBZ. In conclusions, solid dispersions could be a promising delivery of CBZ with improved oral bioavailability and immediate release profiles.

Keywords: carbamazepine, FTIR, kollidon 30, HPMC 6 CPS, PEG 6000, PEG 4000, poloxamer 407, water solubility, povidone k 30, SEM, solid dispersion

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977 Assessment of Causes of Building Collapse in Nigeria

Authors: Olufemi Oyedele

Abstract:

Building collapse (BC) in Nigeria is becoming a regular occurrence, each recording great casualties in the number of lives and materials lost. Building collapse is a situation where building which has been completed and occupied, completed but not occupied or under construction, collapses on its own due to action or inaction of man or due to natural event like earthquake, storm, flooding, tsunami or wildfire. It is different from building demolition. There are various causes of building collapse and each case requires expert judgment to decide the cause of its collapse. Rate of building collapse is a reflection of the level of organization and control of building activities and degree of sophistication of the construction professionals in a country. This study explored the use of case study by examining the causes of six (6) collapsed buildings (CB) across Nigeria. Samples of materials from the sites of the collapsed buildings were taken for testing and analysis, while critical observations were made at the sites to note the conditions of the ground (building base). The study found out that majority of the building collapses in Nigeria were due to poor workmanship, sub-standard building materials, followed by bad building base and poor design. The National Building Code 2006 is not effective due to lack of enforcement and the Physical Development Departments of states and Federal Capital Territory are just mere agents of corruption allowing all types of construction without building approvals.

Keywords: building collapse, concrete tests, differential settlement, integrity test, quality control

Procedia PDF Downloads 535
976 Nutraceutical Potential of Mushroom Bioactive Metabolites and Their Food Functionality

Authors: Jackson Ishara, Ariel Buzera, Gustave N. Mushagalusa, Ahmed R. A. Hammam, Judith Munga, Paul Karanja, John Kinyuru

Abstract:

Numerous mushroom bioactive metabolites, including polysaccharides, eritadenine, lignin, chitosan, mevinolin, and astrakurkurone have been studied in life-threatening conditions and diseases such as diabetes, cardiovascular, hypertension, cancer, DNA damage, hypercholesterolemia, and obesity attempting to identify natural therapies. These bioactive metabolites have shown potential as antiviral and immune system strengthener natural agents through diverse cellular and physiological pathways modulation with no toxicity evidence, widely available, and affordable. In light of the emerging literature, this paper compiles the most recent information describing the molecular mechanisms that underlie the nutraceutical potentials of these mushroom metabolites suggesting their effectiveness if combined with existing drug therapies. The findings raise hope that these mushroom bioactive metabolites may be utilized as natural therapies considering their therapeutic potential while anticipating further research designing clinical trials and developing new drug therapies while encouraging their consumption as a natural adjuvant in preventing and controlling life-threatening conditions and diseases.

Keywords: bioactive metabolites, food functionality, health-threatening conditions, mushrooms, nutraceutical

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975 Enzymatic Activities of Two Iranian Wheat Cultivars Infected with Fusarium Culmorum

Authors: Parastoo Motallebi, Vahid Niknam, Hassan Ebrahimzadeh, Majid Hashemi

Abstract:

Wheat, the most strategically important worldwide crop, is widely grown in various countries. Based on international wheat production statistics (FAOSTAT database), the total production of wheat in 2012 was 13.8 in Iran. Fusarium culmorum is one of the principal causative agents of Fusarium crown rot (FCR), an overwhelming disease of wheat and barley which is in the early stages causing yield losses, stand reductions and rotting of root and lower stem tissues. In this study inoculation of two wheat seedlings of the susceptible cultivar Falat and the partially field-resistant cultivar Pishtaz were carried out in greenhouse conditions and root samples were taken for 6 days. The activity of peroxidase (POX) and polyphenoloxidase (PPO) enzymes were analyzed to identify possible relations between resistance and enzymatic activities. Although the POX and PPO activities in both geno types increased, this significant increase was more dominant in Pishtaz. The results showed an earlier elevation in the activity of these defense related enzymes in semi-resistant cv. Pishtaz after inoculation, suggested that the activities of POX and PPO in wheat geno types play an important role in the induction of resistance to this disease.

Keywords: Defense responses, Fusarium culmorum, Wheat

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974 Reducing Phytic Acid in Rice Grain by Targeted Mutagenesis of a Phospholipase D Gene

Authors: Muhammad Saad Shoaib Khan, Rasbin Basnet, Qingyao Shu

Abstract:

Phospholipids are one of the major classes of lipid comprising 10% of total grain lipid in rice. Phospholipids are the main phosphorus containing lipid in the rice endosperm, contributing to rice palatability and seed storage property. However, in the rice grain, the majority of phosphorus occur in the form of phytic acid and are highly abundant in the bran. Phytic acid, also known as hexaphosphorylated inositol (IP6), are strong chelating agents which reduces the bioavailability of essential dietary nutrients and are therefore less desirable by rice breeders. We used the CRISPR/Cas9 system to generate mutants of a phospholipase D gene (PLDα1), which is responsible for the degradation of phospholipids into phosphatidic acid (PA). In the mutants, we found a significant reduction in the concentration of phytic acid in the grain as compared to the wild-type. The biochemical analysis of the PLDα1 mutants showed that the decrease in production of phosphatidic acid is due to reduced accumulation of CDP-diacylglycerolderived phosphatidylinositol (PI), ultimately leading to lower accumulation of phytic acid in mutants. These results showed that loss of function of PLD in rice leads to lower production of phytic acid, suggesting the potential application of Ospldα1 in breeding rice with less phytic acid.

Keywords: CRISPR/Cas9, phospholipase D, phytic acid, rice

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973 The Determinants of Country Corruption: Unobserved Heterogeneity and Individual Choice- An empirical Application with Finite Mixture Models

Authors: Alessandra Marcelletti, Giovanni Trovato

Abstract:

Corruption in public offices is found to be the reflection of country-specific features, however, the exact magnitude and the statistical significance of its determinants effect has not yet been identified. The paper aims to propose an estimation method to measure the impact of country fundamentals on corruption, showing that covariates could differently affect the extent of corruption across countries. Thus, we exploit a model able to take into account different factors affecting the incentive to ask or to be asked for a bribe, coherently with the use of the Corruption Perception Index. We assume that discordant results achieved in literature may be explained by omitted hidden factors affecting the agents' decision process. Moreover, assuming homogeneous covariates effect may lead to unreliable conclusions since the country-specific environment is not accounted for. We apply a Finite Mixture Model with concomitant variables to 129 countries from 1995 to 2006, accounting for the impact of the initial conditions in the socio-economic structure on the corruption patterns. Our findings confirm the hypothesis of the decision process of accepting or asking for a bribe varies with specific country fundamental features.

Keywords: Corruption, Finite Mixture Models, Concomitant Variables, Countries Classification

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972 Teaching Religious Education: The Ethics and Religious Culture Program as Case Study for Social Change

Authors: Sabrina N. Jafralie, Arzina Zaver

Abstract:

Responding to religious diversity and the need for social change, the Ethics and Religious Culture (ERC) Program was introduced as a mandatory subject for all students in Quebec, Canada. Now that the Quebec provincial government has announced the end of the ERC program, it time to discuss and assess both challenges and successes in it's implementation especially its impact on social change. Though many studies have been written around the wider concepts of religious education and religious literacy in the public system, few studies have included voices from educators. Jafralie and Zaver's qualitative research study examines the potentials and struggles of the ERC Program, and by doing so, raise important considerations around the effective teaching of.  The findings point to several consistent themes that teachers grapple with in regards to curriculum and pedagogy and highlights that in-service teachers are not thoroughly prepared to teach about ethics and religion, nor are teacher education programs effectively preparing pre-service teachers entering the field to deal with the complexities of teaching about religion or social change in their classrooms. The authors suggest avenues in which teacher education for teachers can look like in order for students and teachers to engage meaningfully with religious diversity and be agents of social change. 

Keywords: Pedagogy, Professional Development, Quebec, Teaching

Procedia PDF Downloads 144
971 Off-Farm Work and Cost Efficiency in Staple Food Production among Small-Scale Farmers in North Central Nigeria

Authors: C. E. Ogbanje, S. A. N. D. Chidebelu, N. J. Nweze

Abstract:

The study evaluated off-farm work and cost efficiency in staple food production among small-scale farmers in North Central Nigeria. Multistage sampling technique was used to select 360 respondents (participants and non-participants in off-farm work). Primary data obtained were analysed using stochastic cost frontier and test of means’ difference. Capital input was lower for participants (N2,596.58) than non-participants (N11,099.14). Gamma (γ) was statistically significant. Farm size significantly (p<0.01) increased cost outlay for participants and non-participants. Average input prices of enterprises one and two significantly (p<0.01) increased cost. Sex, household size, credit obtained, formal education, farming experience, and farm income significantly (p<0.05) reduced cost inefficiency for non-participants. Average cost efficiency was 11%. Farm capital was wasted. Participants’ substitution of capital for labour did not put them at a disadvantage. Extension agents should encourage farmers to obtain financial relief from off-farm work but not to the extent of endangering farm cost efficiency.

Keywords: cost efficiency, mean difference, North Central Nigeria, off-farm work, participants and non-participants, small-scale farmers

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970 The Role of Intermediaries in E-Government Adoption in India: Bridging the Digital Divide

Authors: Rajiv Kumar, Amit Sachan, Arindam Mukherjee

Abstract:

Despite the transparency and benefits of e-government, and its potential to serve citizens better, there is low diffusion and adoption of e-government services in India. Limited access to computer and internet, lack of computer and internet skills, low trust in technology, and risk associated in using e-government services are major hindrances in e-government adoption in India. Despite a large number of citizens belonging to the non-adopter category, the government has made some services mandatory to be accessed online where citizens have no other choice. Also despite the digital divide, a large number of citizens prefer online access to government services. In such cases intermediaries like common service centers, internet café and services agents’ roles are significant for accessing e-government services. Hence research is needed to explore this. The study aims to investigate the role of intermediaries in online access to public services by citizens. Qualitative research methodology using semi-structured interview was used. The results show that intermediaries play an important role in bridging the digital divide. The study also highlights on what circumstances citizens are taking help of these intermediaries. The study then highlights its limitations and discusses scope for future study.

Keywords: adoption, digital divide, e-government, India, intermediaries

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969 Perceptions of Greenhouse Vegetable Growers Regarding Use of Biological Control Practices: A Case Study in Jiroft County, Iran

Authors: Hossein Shabanali Fami, Omid Sharifi, Javad Ghasemi, Mahtab Pouratashi, Mona Sadat Moghadasian

Abstract:

The main purpose of this study was to investigate perception of greenhouse vegetable growers regarding use of biological control practices during the growing season. The statistical population of the study included greenhouse vegetable growers in Jiroft county (N=1862). A sample of 137 vegetable growers was selected, using random sampling method. Data were collected via a questionnaire. The validity of the instrument was obtained by the faculty members of the Department of Agricultural Development and Management in the University of Tehran. Cronbach’s alpha was applied to estimate the reliability which showed a high reliability for the instrument. Data was analyzed using SPSS/Windows 13.5. The results revealed that greenhouse vegetable growers had moderate level of perception regarding biological control practices. Levels of vegetable growers’ perceptions regarding biological control practices were different on the basis of their academic qualifications as well as educational level and job. In addition, the results indicated that about 54.1% of variations in vegetable growers’ perceptions could be explained by variables such as awareness of biological control practices, knowledge on pests, annual production and age.

Keywords: greenhouse, biological control, biological agents, perception, vegetable grower

Procedia PDF Downloads 346
968 Synthesis, Electrochemical and Fluorimetric Analysis of Caffeic Cinnamic and Acid-Conjugated Hemorphin Derivatives Designed as Potential Anticonvulsant Agents

Authors: Jana Tchekalarova, Stela Georgieva, Petia Peneva, Petar Todorov

Abstract:

In the present study, a series of bioconjugates of N-modified hemorphine analogs containing second pharmacophore cinnamic acids (CA) or caffeic (KA) were synthesized by a traditional solid-phase Fmoc chemistry method for peptide synthesis. Electrochemical and fluorimetrical analysis and in vivo anticonvulsant activity in mice were conducted on the compounds. The three CA acids (H4-CA, H5-CA, and H7-CA) and three KA acids (H4-KA, H5-KA, and H7-KA)-conjugated hemorphine derivatives showed dose-dependent anticonvulsant activity in the maximal electroshock test (MES) in mice. The KA-conjugated H5-KA derivate was the only compound that suppressed clonic seizures at the lowest dose of 0.5 µg/mouse in the scPTZ test. The activity against the psychomotor seizures in the 6-Hz test was detected only for the H4-CA (0.5 µg) and H4-KA (0.5 µg and 1 µg), respectively. The peptide derivates did not exhibit neurotoxicity in the rotarod test. Our findings suggest that conjugated CA and KA hemorphine peptides can be used as a background for developing hemorphin-related analogs with anticonvulsant activity. Acknowledgements: This study is funded by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project № BG-RRP-2.004-0002, "BiOrgaMCT".

Keywords: hemorphins, caffeic/cinnamic acid, anticonvulsant activity, electrochemistry, fluorimetry

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967 Revolutionizing RNA Extraction: A Unified, Sustainable, and Rapid Protocol for High-Quality Isolation from Diverse Tissues

Authors: Ying Qi Chan, Chunyu Li, Xu Rou Yoyo Ma, Yaya Li, Saber Khederzadeh

Abstract:

In the ever-evolving landscape of genome extraction protocols, the existing methodologies grapple with issues ranging from sub-optimal yields and compromised quality to time-intensive procedures and reliance on hazardous reagents, often necessitating substantial tissue quantities. This predicament is particularly challenging for scientists in developing countries, where resources are limited. Our investigation presents a protocol for the efficient extraction of high-yield RNA from various tissues such as muscle, insect, and plant samples. Noteworthy for its advantages, our protocol stands out as the safest, swiftest (completed in just 38 minutes), most cost-effective (coming in at a mere US$0.017), and highly efficient method in comparison to existing protocols. Notably, our method avoids the use of hazardous or toxic chemicals such as chloroform and phenol and enzymatic agents like RNase and Proteinase K. Our RNA extraction protocol has demonstrated clear advantages over other methods, including commercial kits, in terms of yield. This nucleic acid extraction protocol is more environmentally and research-friendly, suitable for a range of tissues, even in tiny volumes, hence facilitating various genetic diagnosis and researches across the globe.

Keywords: RNA extraction, rapid protocol, universal method, diverse tissues

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966 Protective Effect of hsa-miR-124 against to Bacillus anthracis Toxins on Human Macrophage Cells

Authors: Ali Oztuna, Meral Sarper, Deniz Torun, Fatma Bayrakdar, Selcuk Kilic, Mehmet Baysallar

Abstract:

Bacillus anthracis is one of the biological agents most likely to be used in case of bioterrorist attack as well as being the cause of anthrax. The bacterium's major virulence factors are the anthrax toxins and an antiphagocytic polyglutamic capsule. TEM8 (ANTXR1) and CMG2 (ANTXR2) are ubiquitously expressed type I transmembrane proteins, and ANTXR2 is the major receptor for anthrax toxins. MicroRNAs are 21-24 bp small noncoding RNAs that regulate gene expression by base pairing with the 3' UTR (untranslated regions) of their target mRNAs resulting in mRNA degradation and/or translational repression. MicroRNAs contribute to regulation of most biological processes and influence numerous pathological states like infectious disease. In this study, post-exposure (toxins) protective effect of the hsa-miR-124-3p against Bacillus anthracis was examined. In this context, i) THP-1 and U937 cells were differentiated to MΦ macrophage, ii) miRNA transfection efficiencies were evaluated by flow cytometry and qPCR, iii) protection against Bacillus anthracis toxins were investigated by XTT, cAMP ELISA and MEK2 cleavage assays. Acknowledgements: This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant SBAG-218S467.

Keywords: ANTXR2, hsa-miR-124-3p, MΦ macrophage, THP-1, U937

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965 Antioxidant Potential and Inhibition of Key Enzymes Linked to Alzheimer's Diseases and Diabetes Mellitus by Monoterpene-Rich Essential Oil from Sideritis Galatica Bornm. Endemic to Turkey

Authors: Gokhan Zengin, Cengiz Sarikurkcu, Abdurrahman Aktumsek, Ramazan Ceylan

Abstract:

The present study was designated to characterize the essential oil from S. galatica (SGEOs) and evaluate its antioxidant and enzyme inhibitory activities. Antioxidant capacity were tested different methods including free radical scavenging (DPPH, ABTS and NO), reducing power (FRAP and CUPRAC), metal chelating and phosphomolybdenum. Inhibitory activities were analyzed on acetylcholiesterase, butrylcholinesterase, α-amylase and α-glucosidase. SGEOs were chemically analyzed and identified by gas chromatography (GC) and gas chromatography/mass spectrophotometry (GC/MS). 23 components, representing 98.1% of SGEOs were identified. Monoterpene hydrocarbons (74.1%), especially α- (23.0%) and β-pinene (32.2%), were the main constituents in SGEOs. The main sesquiterpene hydrocarbons were β-caryophyllene (16.9%), Germacrene-D (1.2%) and Caryophyllene oxide (1.2%), respectively. Generally, SGEOs has shown moderate free radical, reducing power, metal chelating and enzyme inhibitory activities. These activities related to chemical profile in SGEOs. Our findings supported that the possible utility of SGEOs is a source of natural agents for food, cosmetics or pharmaceutical industries.

Keywords: sideritis galatica, antioxidant, monoterpenes, cholinesterase, anti-diabetic

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964 Learners as Consultants: Knowledge Acquisition and Client Organisations-A Student as Producer Case Study

Authors: Barry Ardley, Abi Hunt, Nick Taylor

Abstract:

As a theoretical and practical framework, this study uses the student-as-producer approach to learning in higher education, as adopted by the Lincoln International Business School, University of Lincoln, UK. Students as producer positions learners as skilled and capable agents, able to participate as partners with tutors in live research projects. To illuminate the nature of this approach to learning and to highlight its critical issues, the authors report on two guided student consultancy projects. These were set up with the assistance of two local organisations in the city of Lincoln, UK. Using the student as a producer model to deliver the projects enabled learners to acquire and develop a range of key skills and knowledge not easily accessible in more traditional educational settings. This paper presents a systematic case study analysis of the eight organising principles of the student-as-producer model, as adopted by university tutors. The experience of tutors implementing students as producers suggests that the model can be widely applied to benefit not only the learning and teaching experiences of higher education students and staff but additionally a university’s research programme and its community partners.

Keywords: consultancy, learning, student as producer, research

Procedia PDF Downloads 78
963 Broadband Platinum Disulfide Based Saturable Absorber Used for Optical Fiber Mode Locking Lasers

Authors: Hui Long, Chun Yin Tang, Ping Kwong Cheng, Xin Yu Wang, Wayesh Qarony, Yuen Hong Tsang

Abstract:

Two dimensional (2D) materials have recently attained substantial research interest since the discovery of graphene. However, the zero-bandgap feature of the graphene limits its nonlinear optical applications, e.g., saturable absorption for these applications require strong light-matter interaction. Nevertheless, the excellent optoelectronic properties, such as broad tunable bandgap energy and high carrier mobility of Group 10 transition metal dichalcogenides 2D materials, e.g., PtS2 introduce new degree of freedoms in the optoelectronic applications. This work reports our recent research findings regarding the saturable absorption property of PtS2 layered 2D material and its possibility to be used as saturable absorber (SA) for ultrafast mode locking fiber laser. The demonstration of mode locking operation by using the fabricated PtS2 as SA will be discussed. The PtS2/PVA SA used in this experiment is made up of some few layered PtS2 nanosheets fabricated via a simple ultrasonic liquid exfoliation. The operational wavelength located at ~1 micron is demonstrated from Yb-doped mode locking fiber laser ring cavity by using the PtS2 SA. The fabricated PtS2 saturable absorber offers strong nonlinear properties, and it is capable of producing regular mode locking laser pulses with pulse to pulse duration matched with the round-trip cavity time. The results confirm successful mode locking operation achieved by the fabricated PtS2 material. This work opens some new opportunities for these PtS2 materials for the ultrafast laser generation. Acknowledgments: This work is financially supported by Shenzhen Science and Technology Innovation Commission (JCYJ20170303160136888) and the Research Grants Council of Hong Kong, China (GRF 152109/16E, PolyU code: B-Q52T).

Keywords: platinum disulfide, PtS2, saturable absorption, saturable absorber, mode locking laser

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962 Exploring the 1,3-Dipolar Cycloaddition Reaction between Nitrilimine and 6-Methyl-4,5-dihydropyridazin-3(2h)-one through MEDT and Molecular Docking Analysis

Authors: Zineb Ouahdi

Abstract:

Spirocyclic compound derivatives, with their unique heterocyclic motifs, serve as a continual source of inspiration in the pursuit of developing potential therapeutic agents. These compounds are diverse in their chemical structures; some have fully saturated skeletons, while others are partially unsaturated. Nevertheless, these compounds share a characteristic feature with natural products - the presence of at least one heteroatom in one of their rings. The inclusion of a C = O dipolarophile in pyridazinones imparts an exciting aspect for 1,3-dipolar cycloaddition reactions, the focal point of our study. Our research has involved a detailed theoretical investigation of the reaction between ethyl (Z)-2-bromo-2-(2-(p-tolyl)hydrazono)acetate and 6-methyl-4,5-dihydropyridazine-3(2H)-one. This has been accomplished using the DFT/B3LYP/6-31g(d,p) method, intending to illuminate the chemical pathway of this reaction. The chemical reactivity theories we used for this purpose included FMO, TS, and local and global indices derived from conceptual DFT. The theoretical framework outlined in this study allowed us to propose a reaction mechanism for cycloaddition reactions. It also enabled the identification of the potential activities of the analyzed compounds (P1, P2, P3, P4, P5, and P6) against the major protease of the coronavirus disease (COVID-19). This was achieved using various computational tools, including AutoDock Tools, Autodock Vina, Autodock 4, and PYRX.

Keywords: MEDT, pyridazin, cycloaddition, FMO, DFT, docking

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961 Construction of QSAR Models to Predict Potency on a Series of substituted Imidazole Derivatives as Anti-fungal Agents

Authors: Sara El Mansouria Beghdadi

Abstract:

Quantitative structure–activity relationship (QSAR) modelling is one of the main computer tools used in medicinal chemistry. Over the past two decades, the incidence of fungal infections has increased due to the development of resistance. In this study, the QSAR was performed on a series of esters of 2-carboxamido-3-(1H-imidazole-1-yl) propanoic acid derivatives. These compounds have showed moderate and very good antifungal activity. The multiple linear regression (MLR) was used to generate the linear 2d-QSAR models. The dataset consists of 115 compounds with their antifungal activity (log MIC) against «Candida albicans» (ATCC SC5314). Descriptors were calculated, and different models were generated using Chemoffice, Avogadro, GaussView software. The selected model was validated. The study suggests that the increase in lipophilicity and the reduction in the electronic character of the substituent in R1, as well as the reduction in the steric hindrance of the substituent in R2 and its aromatic character, supporting the potentiation of the antifungal effect. The results of QSAR could help scientists to propose new compounds with higher antifungal activities intended for immunocompromised patients susceptible to multi-resistant nosocomial infections.

Keywords: quantitative structure–activity relationship, imidazole, antifungal, candida albicans (ATCC SC5314)

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960 Potential of Entomopathogenic Nematodes to Control Woolly Apple Aphid (Eriosoma lanigerum)

Authors: Nomakholwa F. Stokwe, Antoinette P. Malan

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Woolly apple aphid (WAA), Eriosoma lanigerum, is an important pest of apples worldwide. The aphid feeds above ground on buds and leaf axils and the roots of apple trees. Entomopathogenic nematodes (EPNs) of the two families, Steinernematidae and Heterorhabditidae, and their symbiotic bacteria have generated extensive interest as inundative applied biological control agents of insects. With the development of the resistance of WAA to chemicals, export restrictions, and the inability of parasitoids to control the aphid successfully early in the season, considering EPNs as an alternative biocontrol agent is important. Seven EPN species were tested for their pathogenicity against WAA. Laboratory bioassays identified S. yirgalemense and H. zealandica as being the most virulent against the subterranean stage of the WAA, with a mortality rate of 48% and 38%, respectively. Studies on the effect of WAA size showed that the last instar is most susceptible to infection, whereas smaller instars appear to be too small for nematode penetration and infection. Neither increasing the exposure period of the aphids nor increasing the nematode concentration affected the infection rate positively. The haemolymph of WAA showed an inhibitory effect on the development of the symbiotic bacteria, preventing the completion of the nematode’s life cycle.

Keywords: apples, biocontrol, entomopathogenic nematodes, woolly apple aphid

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959 Factors Affecting Corruption in Ethiopia from Higher Education Instructors' Perceptions: Evidence from Business and Economics College, Bahir Dar University

Authors: Asmamaw Yigzaw Chirkos

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Corruption increasingly has become one of the greatest challenges of the contemporary world. It undermines good government and rule of law and in turn leads to the misallocation of public resources, harms both the private and public sector and particularly hurts the poor. Corruption is found everywhere, but it is deep-rooted in the poor countries of Sub-Saharan Africa countries. Corruption in developing countries continues to be one of the greatest factors of poverty and underdevelopment. As it is the case in other developing countries, in Ethiopia, the culture of corruption has grown roots in the society at large and become endemic. Institutions, which were designed for the regulation of the relationships between citizens and the State, are being used instead for the personal enrichment of public officials and other corrupt private agents. This paper, therefore, assesses the major factors affecting Corruption in Ethiopia from higher education instructors’ Perceptions with special reference to Business and Economics College of Bahir Dar University. The findings of the study support several previously conducted studies in that each factor examined had a moderate to high positive correlation with corruption, where r ranged between .35 and .54. In addition, the 13 variables together explain about 37 percent change in perceived corruption in Ethiopia (R²= .37).

Keywords: Bahir Dar university, corruption, Ethiopia, factors, instructors perceptions

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958 Characterization of the Lytic Bacteriophage VbɸAB-1 against Drug Resistant Acinetobacter baumannii Isolated from Hospitalized Pressure Ulcers Patients

Authors: M. Doudi, M. H. Pazandeh, L. Rahimzadeh Torabi

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Bedsores are pressure ulcers that occur on the skin or tissue due to being immobile and lying in bed for extended periods. Bedsores have the potential to progress into open ulcers, increasing the possibility of variety of bacterial infection. Acinetobacter baumannii, a pathogen of considerable clinical importance, exhibited a significant correlation with Bedsores (pressure ulcers) infections, thereby manifesting a wide spectrum of antibiotic resistance. The emergence of drug resistance has led researchers to focus on alternative methods, particularly phage therapy, for tackling bacterial infections. Phage therapy has emerged as a novel therapeutic approach to regulate the activity of these agents. The management of bacterial infections greatly benefits from the clinical utilization of bacteriophages as a valuable antimicrobial intervention. The primary objective of this investigation consisted of isolating and discerning potent bacteriophage capable of targeting multi drug-resistant (MDR) and extensively drug-resistant (XDR) bacteria obtained from pressure ulcers. In present study, analyzed and isolated A. baumannii strains obtained from a cohort of patients suffering from pressure ulcers at Taleghani Hospital in Ahvaz, Iran. An approach that included biochemical and molecular identification techniques was used to determine the taxonomic classification of bacterial isolates at the genus and species levels. The molecular identification process was facilitated by using the 16S rRNA gene in combination with universal primers 27 F, and 1492 R. Bacteriophage was obtained through the isolation process conducted on treatment plant sewage located in Isfahan, Iran. The main goal of this study was to evaluate different characteristics of phage, such as their appearance, range of hosts they can infect, how quickly they can enter a host, their stability at varying temperatures and pH levels, their effectiveness in killing bacteria, the growth pattern of a single phage stage, mapping of enzymatic digestion, and identification of proteomics patterns. The findings demonstrated that an examination was conducted on a sample of 50 specimens, wherein 15 instances of A. baumannii were identified. These microorganisms are the predominant Gram-negative agents known to cause wound infections in individuals suffering from bedsores. The study's findings indicated a high prevalence of antibiotic resistance in the strains isolated from pressure ulcers, excluding the clinical strains that exhibited responsiveness to colistin.According to the findings obtained from assessments of host range and morphological characteristics of bacteriophage VbɸAB-1, it can be concluded that this phage possesses specificity towards A. Baumannii BAH_Glau1001 was classified as a member of the Plasmaviridae family. The bacteriophage mentioned earlier showed the strongest antibacterial effect at a temperature of 18 °C and a pH of 6.5. Through the utilization of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis on protein fragments, it was established that the bacteriophage VbɸAB-1 exhibited a size range between 50 and 75 kilodaltons (KDa). The numerous research findings on the effectiveness of phages and the safety studies conducted suggest that the phages studied in this research can be considered as a practical solution and recommended approach for controlling and treating stubborn pathogens in burn wounds among hospitalized patients.

Keywords: acinetobacter baumannii, extremely drug- resistant, phage therapy, surgery wound

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957 Health Monitoring of Primates in a Conservation Unit in Brazil

Authors: Elisângela de Albuquerque Sobreira Borovoski, Ricardo Willian Borovoski

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Microbiological infections acquired by animals pose a risk to public health. In public health, monitoring the health of primates is linked to the risk of transmission of zoonoses through scratches, bites and contact with biological samples. The project was approved by the Ethics Committee on the Use of Animals Protocol No. 170/2019. It was authorized by ICMBio Protocol No. 52117-1. The study was carried out in the period 2019-2022 in the municipality of Anápolis. Iron and galvanized wire traps were used and the animals were anesthetized with 4.4mg/kg zolethyl intramuscularly and saliva was collected through swabs. Fifty-three capuchin monkeys were captured from the Onofre Quinan Environmental Park in Anápolis-Goiás for health monitoring purposes. In the laboratory, the samples were deposited on the agar surface and seeded by exhaustion to obtain isolated colonies. These colonies were analyzed according to morphocolonial characteristics. Morphometric characterization and biochemical tests for bacterial identification were performed. A total of 861 bacterial samples were isolated, nine of which were strict anaerobic bacteria of the genus Peptostreptococcus. Previous and constant knowledge of the prevalence of pathogenic agents in biological samples is essential to be prepared to act in pandemic situations.

Keywords: Brazil, microbiology, monkeys, public health

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956 Essential Oil Composition and Antimicrobial Activity of Rosmarinus officinalis L. Grown in Algeria (Djelfa)

Authors: Samah Lakehal, A. Meliani, F. Z. Benrebiha, C. Chaouia

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In the last few years, due to the misuse of antibiotics and an increasing incidence of immunodeficiency-related diseases, the development of microbial drug resistance has become more and more of a pressing problem. Recently, natural products from medicinal plants represent a fertile ground for the development of novel antibacterial agents. Plants essential oils have come more into the focus of phytomedicine. The present study describes antimicrobial activity of Rosmarinus officinalis L. essential oil known medicinally for its powerful antibacterial properties. The essential oil of rosemary obtained by hydrodistillation (using Clevenger type apparatus) growing in Algeria (Djelfa city of south Algeria) was investigated by GC-MS. The essential oil yield of the study was 1.4 %. The major components were found to be camphor, camphene, 1,8-cineole. The essential oil has been tested for antimicrobial activity against eight bacteria (Gram-negative and Gram-positive), and three fungi including Candida albicans. Inhibition of growth was tested by the agar diffusion method based on the determination of the diameter of inhibition. The oil was found to have significant antibacterial activity and therefore can be used as a natural antimicrobial agent for the treatment of several infectious diseases caused by those germs, which have developed resistance to antibiotics.

Keywords: antimicrobial activity, Rosmarinus officinalis L., essential oils, GC/MS, camphor

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955 Mechanical Investigation Approach to Optimize the High-Velocity Oxygen Fuel Fe-Based Amorphous Coatings Reinforced by B4C Nanoparticles

Authors: Behrooz Movahedi

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Fe-based amorphous feedstock powders are used as the matrix into which various ratios of hard B4C nanoparticles (0, 5, 10, 15, 20 vol.%) as reinforcing agents were prepared using a planetary high-energy mechanical milling. The ball-milled nanocomposite feedstock powders were also sprayed by means of high-velocity oxygen fuel (HVOF) technique. The characteristics of the powder particles and the prepared coating depending on their microstructures and nanohardness were examined in detail using nanoindentation tester. The results showed that the formation of the Fe-based amorphous phase was noticed over the course of high-energy ball milling. It is interesting to note that the nanocomposite coating is divided into two regions, namely, a full amorphous phase region and homogeneous dispersion of B4C nanoparticles with a scale of 10–50 nm in a residual amorphous matrix. As the B4C content increases, the nanohardness of the composite coatings increases, but the fracture toughness begins to decrease at the B4C content higher than 20 vol.%. The optimal mechanical properties are obtained with 15 vol.% B4C due to the suitable content and uniform distribution of nanoparticles. Consequently, the changes in mechanical properties of the coatings were attributed to the changes in the brittle to ductile transition by adding B4C nanoparticles.

Keywords: Fe-based amorphous, B₄C nanoparticles, nanocomposite coating, HVOF

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954 Preparation and Application of Biocompatible Nanobioactive Glass as Therapeutic Agents for Bone Tissue Engineering

Authors: P. Shrivastava, S. Vijayalakshmi, A. K. Singh, S. Dalai, R. Teotia, P. Sharma, J. Bellare

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This paper focuses on the synthesis and application of nanobioactive glass for bone regeneration studies. Nanobioactive glass has been synthesized by sol gel method having a combination of silicon, calcium and phosphorous in the molar ratio of 75:21:4. The prepared particles were analyzed for surface morphology by FEG SEM and FEG TEM. Physiochemical properties were investigated using ICP AES, FTIR spectroscopy and X-ray diffraction (XRD) techniques. To ascertain their use for therapeutic use, biocompatibility evaluation of the particles was done by performing soaking studies in SBF and in vitro cell culture studies on MG63 cell lines. Cell morphology was observed by FE SEM and phase contrast microscopy. Nanobioactive glasses (NBG) thus prepared were of 30-200 nm in size, which makes them suitable for nano-biomedical applications. The spherical shape of the particles imparts high surface to volume ratio, promoting fast growth of hydroxyapatite (HA), which is the mineral component of bone. As evaluated by in vitro cell culture studies the NBG was found to enhance the surface activation which enhances osteoblast adhesion. This is an essential parameter to improve bone tissue integration, thereby making nanobioactive glass therapeutically suitable for correcting bone defects.

Keywords: biocompatibility, bone tissue engineering, hydroxyapatite, nanobioactive glass

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953 Preparation and in vivo Assessment of Nystatin-Loaded Solid Lipid Nanoparticles for Topical Delivery against Cutaneous Candidiasis

Authors: Rawia M. Khalil, Ahmed A. Abd El Rahman, Mahfouz A. Kassem, Mohamed S. El Ridi, Mona M. Abou Samra, Ghada E. A. Awad, Soheir S. Mansy

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Solid lipid nanoparticles (SLNs) have gained great attention for the topical treatment of skin associated fungal infection as they facilitate the skin penetration of loaded drugs. Our work deals with the preparation of nystatin loaded solid lipid nanoparticles (NystSLNs) using the hot homogenization and ultrasonication method. The prepared NystSLNs were characterized in terms of entrapment efficiency, particle size, zeta potential, transmission electron microscopy, differential scanning calorimetry, rheological behavior and in vitro drug release. A stability study for 6 months was performed. A microbiological study was conducted in male rats infected with Candida albicans, by counting the colonies and examining the histopathological changes induced on the skin of infected rats. The results showed that SLNs dispersions are spherical in shape with particle size ranging from 83.26±11.33 to 955.04±1.09 nm. The entrapment efficiencies are ranging from 19.73±1.21 to 72.46±0.66% with zeta potential ranging from -18.9 to -38.8 mV and shear-thinning rheological Behavior. The stability studies done for 6 months showed that nystatin (Nyst) is a good candidate for topical SLN formulations. A least number of colony forming unit/ ml (cfu/ml) was recorded for the selected NystSLN compared to the drug solution and the commercial Nystatin® cream present in the market. It can be fulfilled from this work that SLNs provide a good skin targeting effect and may represent promising carrier for topical delivery of Nyst offering the sustained release and maintaining the localized effect, resulting in an effective treatment of cutaneous fungal infection.

Keywords: candida infections, hot homogenization, nystatin, solid lipid nanoparticles, stability, topical delivery

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952 Contribution of Electrochemical Treatment in Treating Textile Dye Wastewater

Authors: Usha N. Murthy, H. B. Rekha, Mahaveer Devoor

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The introduction of more stringent pollution regulations, in relation to financial and social pressures for sustainable development, has pressed toward limiting the volumes of industrial and domestic effluents discharged into the environment-as well as to increase the efforts within research and development of new or more efficient wastewater treatment technologies. Considering both discharge volume and effluent composition, wastewater generated by the textile industry is rated as the most polluting among all industrial sectors. The pollution load is mainly due to spent dye baths, which are composed of unreacted dyes, dispersing agents, surfactants, salts and organics. In the present investigation, the textile dye wastewater was characterized by high colour, chemical oxygen demand (COD), total dissolved solids (TDS) and pH. Electrochemical oxidation process for four plate electrodes was carried out at five different current intensities, out of which 0.14A has achieved maximum percentage removal of COD with 75% and 83% of colour. The COD removal rate in kg COD/h/m2 decreases with increase in the current intensity. The energy consumption increases with increase in the current intensity. Hence, textile dye wastewater can be effectively pre-treated by electrochemical oxidation method where the process limits objectionable colour while leaving the COD associated with organics left for natural degradation thus causing a sustainable reduction in pollution load.

Keywords: electrochemical treatment, COD, colour, environmental engineering

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