Search results for: carrier agents

Authors: Milica Carević, Katarina Banjanac, Marija ĆOrović, Ana Milivojević, Nevena Prlainović, Aleksandar Marinković, Dejan Bezbradica

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Nowadays, considering the growing awareness of functional food beneficial effects on human health, due attention is dedicated to the research in the field of obtaining new prominent products exhibiting improved physiological and physicochemical characteristics. Therefore, different approaches to valuable bioactive compounds synthesis have been proposed. β-Galactosidase, for example, although mainly utilized as hydrolytic enzyme, proved to be a promising tool for these purposes. Namely, under the particular conditions, such as high lactose concentration, elevated temperatures and low water activities, reaction of galactose moiety transfer to free hydroxyl group of the alternative acceptor (e.g. different sugars, alcohols or aromatic compounds) can generate a wide range of potentially interesting products. Up to now, galacto-oligosaccharides and lactulose have attracted the most attention due to their inherent prebiotic properties. The goal of this study was to obtain a novel product sorbitol galactoside, using the similar reaction mechanism, namely transgalactosylation reaction catalyzed by β-galactosidase from Aspergillus oryzae. By using sugar alcohol (sorbitol) as alternative acceptor, a diverse mixture of potential prebiotics is produced, enabling its more favorable functional features. Nevertheless, an introduction of alternative acceptor into the reaction mixture contributed to the complexity of reaction scheme, since several potential reaction pathways were introduced. Therefore, the thorough optimization using response surface method (RSM), in order to get an insight into different parameter (lactose concentration, sorbitol to lactose molar ratio, enzyme concentration, NaCl concentration and reaction time) influences, as well as their mutual interactions on product yield and productivity, was performed. In view of product yield maximization, the obtained model predicted optimal lactose concentration 500 mM, the molar ratio of sobitol to lactose 9, enzyme concentration 0.76 mg/ml, concentration of NaCl 0.8M, and the reaction time 7h. From the aspect of productivity, the optimum substrate molar ratio was found to be 1, while the values for other factors coincide. In order to additionally, improve enzyme efficiency and enable its reuse and potential continual application, immobilization of β-galactosidase onto tailored silica nanoparticles was performed. These non-porous fumed silica nanoparticles (FNS)were chosen on the basis of their biocompatibility and non-toxicity, as well as their advantageous mechanical and hydrodinamical properties. However, in order to achieve better compatibility between enzymes and the carrier, modifications of the silica surface using amino functional organosilane (3-aminopropyltrimethoxysilane, APTMS) were made. Obtained support with amino functional groups (AFNS) enabled high enzyme loadings and, more importantly, extremely high expressed activities, approximately 230 mg proteins/g and 2100 IU/g, respectively. Moreover, this immobilized preparation showed high affinity towards sorbitol galactoside synthesis. Therefore, the findings of this study could provided a valuable contribution to the efficient production of physiologically active galactosides in immobilized enzyme reactors.

Keywords: β-galactosidase, immobilization, silica nanoparticles, transgalactosylation

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Authors: Utpal Das, Sona Das

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InAs/GaSb type-II superlattice (T2SL) Mid-wave infrared (MWIR) focal plane arrays (FPAs) have recently seen rapid development. However, in small pixel size large format FPAs, the occurrence of high mesa sidewall surface leakage current is a major constraint necessitating proper surface passivation. A simple pixel isolation technique in InAs/GaSb T2SL detector arrays without the conventional mesa etching has been proposed to isolate the pixels by forming a more resistive higher band gap material from the SL, in the inter-pixel region. Here, a single step femtosecond (fs) laser anneal of the T2SL structure of the inter-pixel T2SL regions, have been used to increase the band gap between the pixels by QW-intermixing and hence increase isolation between the pixels. The p-i-n photodiode structure used here consists of a 506nm, (10 monolayer {ML}) InAs:Si (1x10¹⁸cm⁻³)/(10ML) GaSb SL as the bottom n-contact layer grown on an n-type GaSb substrate. The undoped absorber layer consists of 1.3µm, (10ML)InAs/(10ML)GaSb SL. The top p-contact layer is a 63nm, (10ML)InAs:Be(1x10¹⁸cm⁻³)/(10ML)GaSb T2SL. In order to improve the carrier transport, a 126nm of graded doped (10ML)InAs/(10ML)GaSb SL layer was added between the absorber and each contact layers. A 775nm 150fs-laser at a fluence of ~6mJ/cm² is used to expose the array where the pixel regions are masked by a Ti(200nm)-Au(300nm) cap. Here, in the inter-pixel regions, the p+ layer have been reactive ion etched (RIE) using CH₄+H₂ chemistry and removed before fs-laser exposure. The fs-laser anneal isolation improvement in 200-400μm pixels due to spatially selective quantum well intermixing for a blue shift of ~70meV in the inter-pixel regions is confirmed by FTIR measurements. Dark currents are measured between two adjacent pixels with the Ti(200nm)-Au(300nm) caps used as contacts. The T2SL quality in the active photodiode regions masked by the Ti-Au cap is hardly affected and retains the original quality of the detector. Although, fs-laser anneal of p+ only etched p-i-n T2SL diodes show a reduction in the reverse dark current, no significant improvement in the full RIE-etched mesa structures is noticeable. Hence for a 128x128 array fabrication of 8μm square pixels and 10µm pitch, SU8 polymer isolation after RIE pixel delineation has been used. X-n+ row contacts and Y-p+ column contacts have been used to measure the optical response of the individual pixels. The photo-response of these 8μm and other 200μm pixels under a 2ns optical pulse excitation from an Optical-Parametric-Oscillator (OPO), shows a peak responsivity of ~0.03A/W and 0.2mA/W, respectively, at λ~3.7μm. Temporal response of this detector array is seen to have a fast response ~10ns followed typical slow decay with ringing, attributed to impedance mismatch of the connecting co-axial cables. In conclusion, response times of a few ns have been measured in 8µm pixels of a 128x128 array. Although fs-laser anneal has been found to be useful in increasing the inter-pixel isolation in InAs/GaSb T2SL arrays by QW inter-mixing, it has not been found to be suitable for passivation of full RIE etched mesa structures with vertical walls on InAs/GaSb T2SL.

Keywords: band-gap blue-shift, fs-laser-anneal, InAs/GaSb T2SL, Inter-pixel isolation, ns-Response, photodiode array

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Authors: Sushma Tejwani, Shoruba Dinakaran, Rupa Rokhade, K. Bhujang Shetty

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Introduction and aim: One of the major causes for failure of trabeculectomy is fibrosis and scarring of subconjunctival tissue around the bleb, and hence intra operative usage of anti-fibrotic agents like Mitomycin C (MMC) has become very popular. However, the long term effects of MMC like thin, avascular bleb, hypotony, bleb leaks and late onset endophthalmitis cannot be ignored, and may preclude its usage in routine trabeculectomy. In this particular study we aim to study the outcomes of trabeculectomy with and without MMC in uncomplicated glaucoma patients. Methods: Retrospective study of series of patients that underwent trabeculectomy with or without cataract surgery in glaucoma department of a tertiary eye care centre by a single surgeon for primary open angle glaucoma (POAG), angle closure glaucoma (PACG), Pseudoexfoliation glaucoma (PXF glaucoma). Patients with secondary glaucoma, juvenile and congenital glaucoma were excluded; also patients undergoing second trabeculectomy were excluded. The outcomes were studied in terms of IOP control at 1 month, 6 months, and 1 year and were analyzed separately for surgical outcomes with and without MMC. Success was considered if IOP was < 16 mmHg on applanation tonometry. Further, the necessity of medication, 5 fluorouracil (5FU) postoperative injections, needling post operatively was noted. Results: Eighty nine patient’s medical records were reviewed, of which 58 patients had undergone trabeculectomy without MMC and 31 with MMC. Mean age was 62.4 (95%CI 61- 64), 34 were females and 55 males. MMC group (n=31): Preoperative mean IOP was 21.1mmHg (95% CI: 17.6 -24.6), and 22 patients had IOP > 16. Three out of 33 patients were on single medication and rests were on multiple drugs. At 1 month (n=27) mean IOP was 12.4 mmHg (CI: 10.7-14), and 31/33 had success. At 6 months (n=18) mean IOP was 13mmHg (CI: 10.3-14.6) and 16/18 had good outcome, however at 1 year only 11 patients were available for follow up and 91% (10/11) had success. Overall, 3 patients required medication and one patient required postoperative injection of 5 FU. No MMC group (n=58): Preoperative mean IOP was 21.9 mmHg (CI: 19.8-24.2), and 42 had IOP > 16 mmHg. 12 out of 58 patients were on single medication and rests were on multiple drugs. At 1 month (n=52) mean IOP was14.6mmHg (CI: 13.2-15.9), and 45/ 58 had IOP < 16mmHg. At 6 months (n=31) mean IOP was 13.5 mmHg (CI: 11.9-15.2) and 26/31 had success, however at 1 year only 23 patients came for follow up and of these 87% (20/23) patients had success. Overall, 1 patient required needling, 5 required 5 FU injections and 5 patients required medication. The success rates at each follow up visit were not significantly different in both the groups. Conclusion: Intra-operative MMC usage may not be required in all patients undergoing trabeculectomy, and the ones without MMC also have fairly good outcomes in primary glaucoma.

Keywords: glaucoma filtration surgery, mitomycin C, outcomes of trabeculectomy, wound modulation

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Authors: AliAkbar Hafezi, Jamshid Abedi, Jalal Taherian, Behnam Kadkhodaei, Mahsa Elahi

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Background. Peripheral neuropathy is a common side effect of the administration of neurotoxic chemotherapy agents. This adverse effect is a major dose-limiting factor of many commonly used chemotherapy drugs. Currently, there are no Food and Drug Administration (FDA) approved medications for the prevention or treatment of chemotherapy-induced peripheral neuropathy. Therefore, this study was performed to investigate the efficacy and safety of metformin on paclitaxel-induced peripheral neuropathy (PIPN). Methods. In this randomized clinical trial, cancer patients who were candidates for chemotherapy with paclitaxel referred to the radiation oncology departments in Iran from 2022 to 2023 were studied. Patients were randomly divided into two groups; 1- Case group (n = 30) received metformin 500 mg orally twice a day after meals during chemotherapy with paclitaxel, and 2- Control group (30 people) received chemotherapy without metformin or any additional medication. Patients were visited in terms of numbness or other neurological symptoms two weeks before chemotherapy, 1-2 days before and weekly during chemotherapy, and at the end of the study. They were assessed by nerve conduction study (NCS) before intervention and one week after the end of chemotherapy. The primary outcome was the efficacy in reducing PIPN and the secondary outcome was adverse effects. Eventually, the outcomes were compared between the two groups of patients. Results. A total of 60 female cancer patients receiving chemotherapy with paclitaxel were evaluated in two groups. The groups were matched in terms of age, body mass index, fasting blood sugar, smoking, pathologic stage, and creatinine levels. The results showed that 18 patients (60.0 %) in the case group and 23 patients (76.6 %) in the control group had PIPN clinically (P = 0.267), and NCS showed 11 patients (36.6 %) in the case group and 15 patients (50.0 %) in the control group suffered from PIPN which no significant difference was observed between the two groups (P = 0.435). Diarrhea (n = 3; 10.0 %) and nausea (n = 3; 10.0 %) were the most common side effects of metformin in the case group and no serious side effects (lactic acidosis and anemia) were found in these patients. Conclusion. This study indicated that metformin did not significantly prevent PIPN in cancer patients receiving chemotherapy, although the frequency of peripheral neuropathy in the case group was lower than in the control group. The use of metformin in the patients had acceptable safety and no serious side effects were reported.

Keywords: peripheral neuropathy, chemotherapy, paclitaxel, metformin

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Authors: Petre Voicu, Mircea Oaida, Radu Vasiu, Catalin Gheorghiu, Aurel Dumitru

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The present work deals with the way in which food and tobacco waste can be used in agriculture. As a result of the lack of efficient technologies for their recycling, we are currently faced with the appearance of appreciable quantities of residual organic residues that find their use only very rarely and only after long storage in landfills. The main disadvantages of long storage of organic waste are the unpleasant smell, the high content of pathogenic agents, and the high content in the water. The release of these enormous amounts imperatively demands the finding of solutions to ensure the avoidance of environmental pollution. The measure practiced by us consists of the processing of this waste in special installations, testing in pilot experimental perimeters, and later administration on agricultural lands without harming the quality of the soil, agricultural crops, and the environment. The current crisis of raw materials and energy also raises special problems in the field of organic waste valorization, an activity that takes place with low energy consumption. At the same time, their composition recommends them as useful secondary sources in agriculture. The transformation of food scraps and other residues concentrated organics thus acquires a new orientation, in which these materials are seen as important secondary resources. The utilization of food and tobacco waste in agriculture is also stimulated by the increasing lack of chemical fertilizers and the continuous increase in their price, under the conditions that the soil requires increased amounts of fertilizers in order to obtain high, stable, and profitable production. The need to maintain and increase the humus content of the soil is also taken into account, as an essential factor of its fertility, as a source and reserve of nutrients and microelements, as an important factor in increasing the buffering capacity of the soil, and the more reserved use of chemical fertilizers, improving the structure and permeability for water with positive effects on the quality of agricultural works and preventing the excess and/or deficit of moisture in the soil.

Keywords: ecology, soil, organic waste, fertility

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Authors: Omar Nasani, Chaza Kouchaji, Muznah Alkhani, Maisaa Abd-alkareem

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Objective: To evaluate the influence of sweetening agents used in pediatric medications on the growth of Streptococcus mutans colonies and its effect on the cariogenic activity in the oral cavity. No previous studies are registered yet in Syrian children. Methods: Specimens were isolated from the oral cavity of pediatric patients, then in-vitro study is applied on locally manufactured liquid pediatric antibiotic drugs, containing natural or synthetic sweeteners. The selected antibiotics are Ampicillin (sucrose), Amoxicillin (sucrose), Amoxicillin + Flucloxacillin (sorbitol), Amoxicillin+Clavulanic acid (Sorbitol or sucrose). These antibiotics have a known inhibitory effect on gram positive aerobic/anaerobic bacteria especially Streptococcus mutans strains in children’s oral biofilm. Five colonies are studied with each antibiotic. Saturated antibiotics were spread on a 6mm diameter filter disc. Incubated culture media were compared with each other and with the control antibiotic discs. Results were evaluated by measuring the diameter of the inhibition zones. The control group of antibiotic discs was resourced from Abtek Biologicals Ltd. Results: The diameter of inhibition zones around discs of antibiotics sweetened with sorbitol was larger than those sweetened with sucrose. The effect was most important when comparing Amoxicillin + Clavulanic Acid (sucrose 25mm; versus sorbitol 27mm). The highest inhibitory effect was observed with the usage of Amoxicillin + Flucloxacillin sweetened with sorbitol (38mm). Whereas the lowest inhibitory effect was observed with Amoxicillin and Ampicillin sweetened with sucrose (22mm and 21mm). Conclusion: The results of this study indicate that although all selected antibiotic produced an inhibitory effect on S. mutans, sucrose weakened the inhibitory action of the antibiotic to varying degrees, meanwhile antibiotic formulations containing sorbitol simulated the effects of the control antibiotic. This study calls attention to effects of sweeteners included in pediatric drugs on the oral hygiene and tooth decay.

Keywords: pediatric, dentistry, antibiotics, streptococcus mutans, biofilm, sucrose, sugar free

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Authors: A. P. Attanayake, K. A. P. W. Jayatilaka, L. K. B. Mudduwa, C. Pathirana

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Triggering of β-cell regeneration is a recognized therapeutic strategy for the treatment of type 1 diabetes mellitus. One such approach to foster restoration and regeneration of β-cells is from exogenous natural extracts. The aim of the present study was to investigate and compare the β-cell regenerative potentials of the extracts of Spondias pinnata (Linn. f.) Kurz, Coccinia grandis (L.) Voigt and Gmelina arborea Roxb. in alloxan induced diabetic rats. Wistar rats were divided in to six groups (n=6); healthy untreated rats, alloxan induced diabetic untreated rats (150 mg/kg, ip), diabetic rats receiving the extracts of S. pinnata (1.0 g/kg), C. grandis (0.75 g/kg), G. arobrea (1.00 g/kg) and diabetic rats receiving glibenclamide (0.5 mg/kg) for 30 days. The assessment of selected biochemical parameters, histopathology and immunohistochemistry in the pancreatic tissue were done on the 30th day. The reduction in the percentage of HbA1C was in the decreasing order of C. grandis (35%), G. arborea (31%) and S. pinnata (29%) in alloxan induced diabetic rats (p< 0.05). The concentration of serum fructosamine, insulin and C-peptide were decreased significantly in a decreasing order of C. grandis (30%, 72%, 51%), G. arborea (25%, 44%, 44%) and S. pinnata (27%, 34%, 24%) in alloxan induced diabetic rats (p < 0.05). The extent of β-cell regeneration was in the decreasing order of C. grandis, G. arborea, S. pinnata reflected through the increased percentage of insulin secreting β-cells in alloxan induced diabetic rats. The extract of C. grandis produced the highest degree of β-cell regeneration demonstrated through an increase in the number of islets and percentage of the insulin secreting β-cells (75%) in the pancreas of diabetic rats (p < 0.05). Further the C. grandis extract produced a significant increase in mean profile diameter in small (118%), average (10%), and large (13%) islets as compared with diabetic control rats respectively. However, statistically significant increase in the islet profile diameter was shown only in average (2%) and large (5%) islets in the G. arborea extract treated rats and large islets (5%) in S. pinnata extract treated diabetic rats (p < 0.05). The β-cell regeneration potency was in the decreasing order of C. grandis (0.75 g/kg), G. arborea (1.00 g/kg) and S. pinnata (1.00 g/kg) in alloxan induced diabetic rats. The three plant extracts may be useful as natural agents of triggering the β-cell regeneration in the management of type 1 diabetes mellitus.

Keywords: alloxan-induced diabetic rats, β-cell regeneration, histopathology, immunohistochemistry

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Authors: Noura El-Ahmady El-Naggar

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L-asparaginase is an important enzyme as therapeutic agents used in combination therapy with other drugs in the treatment of acute lymphoblastic leukemia in children. L-asparaginase producing actinomycete strain, NEAE-K, was isolated from soil sample and identified on the basis of morphological, cultural, physiological and biochemical properties, together with 16S rDNA sequence as new subsp. Streptomyces rochei subsp. chromatogenes NEAE-K and sequencing product (1532 bp) was deposited in the GenBank database under accession number KJ200343. The study was conducted to screen parameters affecting the production of L-asparaginase by Streptomyces rochei subsp. chromatogenes NEAE-K on solid state fermentation using Plackett–Burman experimental design. Sixteen different independent variables including incubation time, moisture content, inoculum size, temperature, pH, soybean meal+ wheat bran, dextrose, fructose, L-asparagine, yeast extract, KNO3, K2HPO4, MgSO4.7H2O, NaCl, FeSO4. 7H2O, CaCl2, and three dummy variables were screened in Plackett–Burman experimental design of 20 trials. The most significant independent variables affecting enzyme production (dextrose, L-asparagine and K2HPO4) were further optimized by the central composite design. As a result, a medium of the following formula is the optimum for producing an extracellular L-asparaginase by Streptomyces rochei subsp. chromatogenes NEAE-K from solid state fermentation: g/L (soybean meal+ wheat bran 15, dextrose 3, fructose 4, L-asparagine 8, yeast extract 2, KNO3 1, K2HPO4 2, MgSO4.7H2O 0.5, NaCl 0.1, FeSO4. 7H2O 0.02, CaCl2 0.01), incubation time 7 days, moisture content 50%, inoculum size 3 mL, temperature 30°C, pH 8.5.

Keywords: streptomyces rochei subsp. chromatogenes neae-k, 16s rrna, identification, solid state fermentation, l-asparaginase production, plackett-burman design, central composite design

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Authors: Joan Edwards, J. Lawlor

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Technological innovation is frequently defined in terms of bringing a new invention to market through a relatively straightforward process of diffusion. In reality, this process is complex and non-linear in nature, and includes social and cognitive factors that influence the development of an emerging technology and its related market or environment. As recent studies contend technological trajectory is part of technological paradigms, which arise from the expectations and desires of industry agents and results in co-evolution, it may be realised that social factors play a major role in the development of a technology. It is conjectured that collective social behaviour is fuelled by individual motivations and expectations, which inform the possibilities and uses for a new technology. The individual outlook highlights the issues present at the micro-level of developing a technology. Accordingly, this may be zoomed out to realise how these embedded social structures, influence activities and expectations at a macro level and can ultimately strategically shape the development and use of a technology. These social factors rely on communication to foster the innovation process. As innovation may be defined as the implementation of inventions, technological change results from the complex interactions and feedback occurring within an extended environment. The framework presented in this paper, recognises that social mechanisms provide the basis for an iterative dialogue between an innovator, a new technology, and an environment - within which social and cognitive ‘identity-shaping’ elements of the innovation process occur. Identity-shaping characteristics indicate that an emerging technology has a performative nature that transforms, alters, and ultimately configures the environment to which it joins. This identity–shaping quality is termed as ‘performative’. This paper examines how technologies evolve within a socio-technological sphere and how 'performativity' facilitates the process. A framework is proposed that incorporates the performative elements which are identified as feedback, iteration, routine, expectations, and motivations. Additionally, the concept of affordances is employed to determine how the role of the innovator and technology change over time - constituting a more conducive environment for successful innovation.

Keywords: affordances, framework, performativity, strategic innovation

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Authors: Sophia Melanson Ricciardone

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Common vexations concerning the impact of contemporary media technology on our daily lives tend to conjure mental representations of digital specters that surreptitiously invade the privacy of our most intimate spaces. While legitimacy assuredly sustains these concerns, examining them in isolation from other attributable phenomena to the problems created by our hyper-mediated conditions does not supply a complete account of the deleterious cost of integrating digital affordances into the banal cadence of our shared socio-cultural realities. As we continue to subconsciously delegate facets of our social and cognitive lives to digital technology, the very faculties that have enabled our species to thrive and invent technology in the first place are at risk of attrition – namely our capacity to sustain attention while synthesizing information in working memory to produce creative and inventive constructions for our shared social existence. Though the offloading of knowledge-keeping to fellow social agents belonging to our family and community circles is an enduring intuitive phenomenon across human societies – what social psychologists refer to as transactive memory – in offloading our various socio-cognitive faculties to digital technology, we may plausibly be supplanting the visceral social connections forged by transactive memory. This paper will present related research and literature produced across the disciplines of sociobiology, socio-cultural anthropology, social psychology, cognitive semiotics and communication and media studies that directly and indirectly address the social precarity cultivated by digital technologies. This body of scholarly work will then be situated within common areas of interest belonging to digital anthropology, including the groundbreaking work of Pavel Curtis, Christopher Kelty, Lynn Cherny, Vincent Duclos, Nick Seaver, and Sherry Turkle. It is anticipated that in harmonizing these overlapping areas of intradisciplinary interest, this paper can weave together the disparate connections across spheres of knowledge that help delineate the conditions of our contemporary digital existence.

Keywords: cognition, digital media, knowledge keeping, transactive memory

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Authors: Ana Luiza Aranha

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This paper contributes to the discussions that consider corruption as a challenge to the establishment of more democratically inclusive societies in Latin America. The paper advocates an intrinsic connection between democratic principles and corruption control – it is only possible to achieve just forms of democratic life if accountability institutions are able to control corruption, and therefore control the political exclusions that it brings. Departing from a non-trivial approach to corruption, and recognizing a gap in democratic theory when thinking about this phenomenon, corruption is understood as the breakdown of the democratic inclusive rule, whereby political decisions are made (and actions were taken) in spite of those potentially affected by them. Based on this idea, this paper proposes a new way of measuring corruption, moving away from usual aggregate measures – such as the Corruption Perception Index – and case studies of corruption scandals. The main argument sustains that corruption is intrinsically connected with the ability to be accountable and to provide public justification for the political conduct. The point advocated is that corruption involves a dimension of political exclusion. It generates a private benefit which is, from a democratic point of view, illegitimate, since it benefits some at the expense of the decisions made by the political community. Corruption is then a form of exclusion based on deception and opacity - for corruption, there is no plausible justification. Empirically, the paper uses the audit reports produced by the Brazilian anti-corruption agency (the CGU - Office of the Comptroller General) in its Inspections From Public Lotteries Program to exemplify how we can use this definition to separate corruption cases from mismanagement irregularities. On one side, there is poor management and inefficiencies, and, on the other, corruption, defined by the implausibility of public justifications – because the public officials would have to publicize illegitimate privileges and undue advantages. CGU reports provide the justifications given by the public officials for the irregularities found and also the acceptance or not by the control agency of these justifications. The analysis of this dialogue – between public officials and control agents – makes it possible to divide the irregularities on those that can be publicly justified versus those that cannot. In order to hold public officials accountable for their actions, making them responsible for the exclusions that they may cause (such as corruption), the accountability institutions fulfil an important role in reinforcing and empowering democracy and its basic inclusive condition.

Keywords: accountability, brazil, corruption, democracy

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Authors: Renata Gerhardt, Detlev Belder

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Raman spectroscopy has attracted much attention as a structurally descriptive and label-free detection method. It is particularly suited for chemical analysis given as it is non-destructive and molecules can be identified via the fingerprint region of the spectra. In this work possibilities are investigated how to integrate Raman spectroscopy as a detection method for chip-based chromatography, making use of a droplet interface. A demanding task in lab-on-a-chip applications is the specific and sensitive detection of low concentrated analytes in small volumes. Fluorescence detection is frequently utilized but restricted to fluorescent molecules. Furthermore, no structural information is provided. Another often applied technique is mass spectrometry which enables the identification of molecules based on their mass to charge ratio. Additionally, the obtained fragmentation pattern gives insight into the chemical structure. However, it is only applicable as an end-of-the-line detection because analytes are destroyed during measurements. In contrast to mass spectrometry, Raman spectroscopy can be applied on-chip and substances can be processed further downstream after detection. A major drawback of Raman spectroscopy is the inherent weakness of the Raman signal, which is due to the small cross-sections associated with the scattering process. Enhancement techniques, such as surface enhanced Raman spectroscopy (SERS), are employed to overcome the poor sensitivity even allowing detection on a single molecule level. In SERS measurements, Raman signal intensity is improved by several orders of magnitude if the analyte is in close proximity to nanostructured metal surfaces or nanoparticles. The main gain of lab-on-a-chip technology is the building block-like ability to seamlessly integrate different functionalities, such as synthesis, separation, derivatization and detection on a single device. We intend to utilize this powerful toolbox to realize Raman detection in chip-based chromatography. By interfacing on-chip separations with a droplet generator, the separated analytes are encapsulated into numerous discrete containers. These droplets can then be injected with a silver nanoparticle solution and investigated via Raman spectroscopy. Droplet microfluidics is a sub-discipline of microfluidics which instead of a continuous flow operates with the segmented flow. Segmented flow is created by merging two immiscible phases (usually an aqueous phase and oil) thus forming small discrete volumes of one phase in the carrier phase. The study surveys different chip designs to realize coupling of chip-based chromatography with droplet microfluidics. With regards to maintaining a sufficient flow rate for chromatographic separation and ensuring stable eluent flow over the column different flow rates of eluent and oil phase are tested. Furthermore, the detection of analytes in droplets with surface enhanced Raman spectroscopy is examined. The compartmentalization of separated compounds preserves the analytical resolution since the continuous phase restricts dispersion between the droplets. The droplets are ideal vessels for the insertion of silver colloids thus making use of the surface enhancement effect and improving the sensitivity of the detection. The long-term goal of this work is the first realization of coupling chip based chromatography with droplets microfluidics to employ surface enhanced Raman spectroscopy as means of detection.

Keywords: chip-based separation, chip LC, droplets, Raman spectroscopy, SERS

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Authors: Neslihan Demirci, Serdar Durdağı

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Mycobacterium tuberculosis is still a worldwide disease-causing agent that, according to WHO, led to the death of 1.5 million people from tuberculosis (TB) in 2020. The bacteria reside in macrophages located specifically in the lung. There is a known quadruple drug therapy regimen for TB consisting of isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), and ethambutol (EMB). Over the past 60 years, there have been great contributions to treatment options, such as recently approved delamanid (OPC67683) and bedaquiline (TMC207/R207910), targeting mycolic acid and ATP synthesis, respectively. Also, there are natural compounds that can block the tryptophanyl-tRNA synthetase (TrpRS) enzyme, chuangxinmycin, and indolmycin. Yet, already the drug resistance is reported for those agents. In this study, the newly released TrpRS enzyme structure is investigated for potential inhibitor drugs from already synthesized molecules to help the treatment of resistant cases and to propose an alternative drug for the quadruple drug therapy of tuberculosis. Maestro, Schrodinger is used for docking and molecular dynamic simulations. In-house library containing ~8000 compounds among FDA-approved indole-containing compounds, a total of 57 obtained from the ChemBL were used for both ATP and tryptophan binding pocket docking. Best of indole-containing 57 compounds were subjected to hit expansion and compared later with virtual screening workflow (VSW) results. After docking, VSW was done. Glide-XP docking algorithm was chosen. When compared, VSW alone performed better than the hit expansion module. Best scored compounds were kept for ten ns molecular dynamic simulations by Desmond. Further, 100 ns molecular dynamic simulation was performed for elected molecules according to Z-score. The top three MMGBSA-scored compounds were subjected to steered molecular dynamic (SMD) simulations by Gromacs. While SMD simulations are still being conducted, ponesimod (for multiple sclerosis), vilanterol (β₂ adrenoreceptor agonist), and silodosin (for benign prostatic hyperplasia) were found to have a significant affinity for tuberculosis TrpRS, which is the propulsive force for the urge to expand the research with in vitro studies. Interestingly, top-scored ponesimod has been reported to have a side effect that makes the patient prone to upper respiratory tract infections.

Keywords: drug repurposing, molecular dynamics, tryptophanyl-tRNA synthetase, tuberculosis

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Authors: Ayca Bilginoglu, Belma Turan

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Metabolic syndrome, is associated impaired blood glucose level, insulin resistance, dyslipidemia caused by abdominal obesity. Also, it is related with cardiovascular risk accumulation and cardiomyopathy. The hypothesis of this study was to examine the effect of thiazolidinediones such as pioglitazone which is widely used insulin-sensitizing agents that improve glycemic control, on intracellular Na+ homeostasis in metabolic syndrome-induced cardiomyopathy in male rats. Male Wistar-Albino rats were randomly divided into three groups, namely control (Con, n=7), metabolic syndrome (MetS, n=7) and pioglitazone treated metabolic syndrome group (MetS+PGZ, n=7). Metabolic syndrome was induced by providing drinking water that was 32% sucrose, for 18 weeks. All of the animals were exposed to a 12 h light – 12 h dark cycle. Abdominal obesity and glucose intolerance had measured as a marker of metabolic syndrome. Intracellular Na+ ([Na+]i) is an important modulator of excitation–contraction coupling in heart. [Na+]i at rest and [Na+]i during pacing with electrical field stimulation in 0.2 Hz, 0.8 Hz, 2.0 Hz stimulation frequency were recorded in cardiomyocytes. Also, Na+ channel current (INa) density and I-V curve were measured to understand [Na+]i homeostasis. In results, high sucrose intake, as well as the normal daily diet, significantly increased body mass and blood glucose level of the rats in the metabolic syndrome group as compared with the non-treated control group. In MetS+PZG group, the blood glucose level and body inclined to decrease to the Con group. There was a decrease in INa density and there was a shift both activation and inactivation curve of INa. Pioglitazone reversed the shift to the control side. Basal [Na+]i either MetS and Con group were not significantly different, but there was a significantly increase in [Na+]i in stimulated cardiomyocytes in MetS group. Furthermore, pioglitazone had not effect on basal [Na+]i but it reversed the increase in [Na+]i in stimulated cardiomyocytes to the that of Con group. Results of the present study suggest that pioglitazone has a significant effect on the Na+ homeostasis in the metabolic syndrome induced cardiomyopathy in rats. All animal procedures and experiments were approved by the Animal Ethics Committee of Ankara University Faculty of Medicine (2015-2-37).

Keywords: insulin resistance, intracellular sodium, metabolic syndrome, sodium current

Procedia PDF Downloads 285

Authors: Ridwaan N. Milase, Leonardo J. Van Zyl, Marla Trindade

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American foulbrood (AFB) is the world’s most devastating honeybee disease that has drastically reduced the population of Apis mellifera capensis since 2009. The outbreak has jeopardized the South African bee keeping industry as well as the agricultural sector dependent on honeybees for honey production and pollination, leading to significant economic losses. AFB is caused by Paenibacillus larvae, a spore-forming, Gram positive facultative anaerobic and flagellated bacterium. The use of antibiotics within beehives has selected for resistant strains of P. larvae, while the current practice of burning spore contaminated beehives and equipment contributes to the economic losses in the honeybee-keeping industry. Therefore, phage therapy is proposed as a promising alternative to combat P. larvae strains affecting A. mellifera capensis. The genomes of two P. larvae strains isolated from infected combs in the Western Cape have been sequenced and annotated using bioinformatics tools. Genome analyses has revealed that these P. larvae strains are lysogens to more than 6 different prophages and possess different type of clustered regularly interspaced short palindromic repeat (CRISPRs) regions per strain. Active prophages from one of the two P. larvae strains were detected and identified using PCR. Electron microscopy was used to determine the family of the identified active prophages. Lytic bacteriophages that specifically target the two P. larvae strains were purified from sewage wastewater, beehive materials, and soil samples to investigate their potential development as anti-P. larvae agents. Another alternative treatment being investigated is the development of a prophage endolysin cocktail. Endolysin genes of the prophages have been targeted, cloned and expressed in Escherichia coli. The heterologously expressed endolysins have been purified and are currently being assessed for their lytic activity against P. larvae strains and other commensal microorganisms that compose the honeybee larvae microbiota. The study has shown that phage therapy and endolysins have a great potential as alternative control methods for AFB disease affecting A. mellifera capensis.

Keywords: American foulbrood, bacteriophage, honeybee, Paenibacillus larvae

Procedia PDF Downloads 181

Authors: Emre Bayamlıoğlu

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This paper aims to provide an account of the legal and the regulative aspects of the algorithmic reputation systems with a special emphasis on the sharing economy (i.e., Uber, Airbnb, Lyft) business model. The first section starts with an analysis of the legal and commercial nature of the tripartite relationship among the parties, namely, the host platform, individual sharers/service providers and the consumers/users. The section further examines to what extent an algorithmic system of reputational information could serve as an alternative to legal regulation. Shortcomings are explained and analyzed with specific examples from Airbnb Platform which is a pioneering success in the sharing economy. The following section focuses on the issue of governance and control of the reputational information. The section first analyzes the legal consequences of algorithmic filtering systems to detect undesired comments and how a delicate balance could be struck between the competing interests such as freedom of speech, privacy and the integrity of the commercial reputation. The third section deals with the problem of manipulation by users. Indeed many sharing economy businesses employ certain techniques of data mining and natural language processing to verify consistency of the feedback. Software agents referred as "bots" are employed by the users to "produce" fake reputation values. Such automated techniques are deceptive with significant negative effects for undermining the trust upon which the reputational system is built. The third section is devoted to explore the concerns with regard to data mobility, data ownership, and the privacy. Reputational information provided by the consumers in the form of textual comment may be regarded as a writing which is eligible to copyright protection. Algorithmic reputational systems also contain personal data pertaining both the individual entrepreneurs and the consumers. The final section starts with an overview of the notion of reputation as a communitarian and collective form of referential trust and further provides an evaluation of the above legal arguments from the perspective of public interest in the integrity of reputational information. The paper concludes with certain guidelines and design principles for algorithmic reputation systems, to address the above raised legal implications.

Keywords: sharing economy, design principles of algorithmic regulation, reputational systems, personal data protection, privacy

Procedia PDF Downloads 465

Authors: Asma Chbani, Douaa Salim, Josephine Al Alam, Pascale De Caro

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Penicillium digitatum, the causal agent of citrus green mold, is responsible for 90% of post-harvest losses. Chemical fungicides remain the most used products for protection against this pathogen but are also responsible for damage to human health and the environment. The aim of this study is to evaluate the ability of Spinacia oleracea extract to serve as biological control agents, an alternative to harmful synthetic fungicides, against orange decay for storing fruit caused by P. digitatum. In this study, we studied the implication of a crude extract of a green plant, Spinacia oleracea, in the protection of oranges against P. digitatum. Thus, in vivo antifungal tests as well as adhesion test were done. For in vivo antifungal test, oranges were pulverized with the prepared crude extracts at different concentrations ranged from 25 g L⁻¹ to 200 g L⁻¹, contaminated by the fungus and then observed during 8 weeks for their macroscopic changes at 24°C. For adhesion test, the adhesion index is defined as the number of Penicillium digitatum spores fixed per orange cell. An index greater than 25 is the indicator of a strong adhesion, whereas for an index less than 10, the adhesion is low. Ten orange cells were examined in triplicate for each extract, and the averages of adherent cells were calculated. Obtained results showed an inhibitory activity of the Penicillium development with the aqueous extract of dry Spinacia oleracea with a concentration of 50 g L⁻¹ considered as the minimal protective concentration. The prepared extracts showed a greater inhibition of the development of P. digitatum up to 10 weeks, even greater than the fungicide control Nystatin. Adhesion test’s results showed that the adhesion of P. digitatum spores to the epidermal cells of oranges in the presence of the crude spinach leaves extract is weak; the mean of the obtained adhesion index was estimated to 2.7. However, a high adhesion was observed with water used a negative control. In conclusion, all these results confirm that the use of this green plant highly rich in chlorophyll having several phytotherapeutic activities, could be employed as a great treatment for protection of oranges against mold and also as an alternative for chemical fungicides.

Keywords: Penicillium digitatum, Spinacia oleracea, oranges, biological control, postharvest diseases

Procedia PDF Downloads 172

Authors: Oscar Orlando Ortiz Rodriguez, Raquel A. Villamizar-G, Alexander Araque

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There is a total of 1027 municipal development plants in Colombia, 70% of municipalities had Potable Water Treatment Plants (PWTPs) in urban areas and 20% in rural areas. These PWTPs are typically supplied by surface waters (mainly rivers) and resort to gravity, pumping and/or mixed systems to get the water from the catchment point, where the first stage of the potable water process takes place. Subsequently, a series of conventional methods are applied, consisting in a more or less standardized sequence of physicochemical and, sometimes, biological treatment processes which vary depending on the quality of the water that enters the plant. These processes require energy and chemical supplies in order to guarantee an adequate product for human consumption. Therefore, in this paper, we applied the environmental methodology of Life Cycle Assessment (LCA) to evaluate the environmental loads of a potable water treatment plant (PWTP) located in northeastern Colombia following international guidelines of ISO 14040. The different stages of the potable water process, from the catchment point through pumping to the distribution network, were thoroughly assessed. The functional unit was defined as 1 m³ of water treated. The data were analyzed through the database Ecoinvent v.3.01, and modeled and processed in the software LCA-Data Manager. The results allowed determining that in the plant, the largest impact was caused by Clarifloc (82%), followed by Chlorine gas (13%) and power consumption (4%). In this context, the company involved in the sustainability of the potable water service should ideally reduce these environmental loads during the potable water process. A strategy could be the use of Clarifloc can be reduced by applying coadjuvants or other coagulant agents. Also, the preservation of the hydric source that supplies the treatment plant constitutes an important factor, since its deterioration confers unfavorable features to the water that is to be treated. By concluding, treatment processes and techniques, bioclimatic conditions and culturally driven consumption behavior vary from region to region. Furthermore, changes in treatment processes and techniques are likely to affect the environment during all stages of a plant’s operation cycle.

Keywords: climate change, environmental impact, life cycle assessment, treated water

Procedia PDF Downloads 224

Authors: Anubhav Kumar Dwivedi, Arshad Khan, S. N. Tripathi, Manish Joshi, Gaurav Mishra, Dinesh Nath, Naveen Tiwari, B. K. Sapra

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In a nuclear reactor accident scenario, a large number of fission products may release to the piping system of the primary heat transport. The released fission products, mostly in the form of the aerosol, get deposited on the inner surface of the piping system mainly due to gravitational settling and thermophoretic deposition. The removal processes in the complex piping system are controlled to a large extent by the thermal-hydraulic conditions like temperature, pressure, and flow rates. These parameters generally vary with time and therefore must be carefully monitored to predict the aerosol behavior in the piping system. The removal process of aerosol depends on the size of particles that determines how many particles get deposit or travel across the bends and reach to the other end of the piping system. The released aerosol gets deposited onto the inner surface of the piping system by various mechanisms like gravitational settling, Brownian diffusion, thermophoretic deposition, and by other deposition mechanisms. To quantify the correct estimate of deposition, the identification and understanding of the aforementioned deposition mechanisms are of great importance. These mechanisms are significantly affected by different flow and thermodynamic conditions. Thermophoresis also plays a significant role in particle deposition. In the present study, a series of experiments were performed in the piping system of the National Aerosol Test Facility (NATF), BARC using metal aerosols (zinc) in dry environments to study the spatial distribution of particles mass and number concentration, and their depletion due to various removal mechanisms in the piping system. The experiments were performed at two different carrier gas flow rates. The commercial CFD software FLUENT is used to determine the distribution of temperature, velocity, pressure, and turbulence quantities in the piping system. In addition to the in-built models for turbulence, heat transfer and flow in the commercial CFD code (FLUENT), a new sub-model PBM (population balance model) is used to describe the coagulation process and to compute the number concentration along with the size distribution at different sections of the piping. In the sub-model coagulation kernels are incorporated through user-defined function (UDF). The experimental results are compared with the CFD modeled results. It is found that most of the Zn particles (more than 35 %) deposit near the inlet of the plenum chamber and a low deposition is obtained in piping sections. The MMAD decreases along the length of the test assembly, which shows that large particles get deposited or removed in the course of flow, and only fine particles travel to the end of the piping system. The effect of a bend is also observed, and it is found that the relative loss in mass concentration at bends is more in case of a high flow rate. The simulation results show that the thermophoresis and depositional effects are more dominating for the small and larger sizes as compared to the intermediate particles size. Both SEM and XRD analysis of the collected samples show the samples are highly agglomerated non-spherical and composed mainly of ZnO. The coupled model framed in this work could be used as an important tool for predicting size distribution and concentration of some other aerosol released during a reactor accident scenario.

Keywords: aerosol, CFD, deposition, coagulation

Procedia PDF Downloads 144

Authors: Juan C. Gutierrez-Estrada, Inmaculada Pulido-Calvo, Ignacio De La Rosa, Antonio Peregrin, Fernando Gomez-Bravo, Samuel Lopez-Dominguez, Alejandro Garrocho-Cruz, Jairo Castro-Gutierrez

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The semi-intensive aquaculture in traditional earth ponds is the main rearing system in Southern Spain. These fish rearing systems are approximately two thirds of aquatic production in this area which has made a significant contribution to the regional economy in recent years. In this type of rearing system, a crucial aspect is the correct quantification and control of the fish abundance in the ponds because the fish farmer knows how many fishes he puts in the ponds but doesn’t know how many fishes will harvest at the end of the rear period. This is a consequence of the mortality induced by different causes as pathogen agents as parasites, viruses and bacteria and other factors as predation of fish-eating birds and poaching. Track the fish abundance in these installations is very difficult because usually the ponds take up a large area of land and the management of the water flow is not automatized. Therefore, there is a very high degree of uncertainty on the abundance fishes which strongly hinders the management and planning of the sales. A novel and non-invasive procedure to count fishes in the ponds is by the means of imaging sonars, particularly fixed systems and/or linked to aquatic vehicles as Remotely Operated Vehicles (ROVs). In this work, a method based on census stations procedures is proposed to evaluate the fish abundance estimation accuracy using images obtained of multibeam sonars. The results indicate that it is possible to obtain a realistic approach about the number of fishes, sizes and therefore the biomass contained in the ponds. This research is included in the framework of the KTTSeaDrones Project (‘Conocimiento y transferencia de tecnología sobre vehículos aéreos y acuáticos para el desarrollo transfronterizo de ciencias marinas y pesqueras 0622-KTTSEADRONES-5-E’) financed by the European Regional Development Fund (ERDF) through the Interreg V-A Spain-Portugal Programme (POCTEP) 2014-2020.

Keywords: census station procedure, fish biomass, semi-intensive aquaculture, multibeam sonars

Procedia PDF Downloads 229

Authors: Anwar ul Haq

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Muhammad Iqbal was arguably the most significant South Asian Islamic philosopher of the last two centuries. While he is the most revered philosopher of the region, particularly in Pakistan, he is probably the least studied philosopher outside the region. The paper offers a philosophical reconstruction of Iqbal’s view of human agency; it has three sections. Section 1 focuses on Iqbal’s starting point of reflection in practical philosophy (inspired by Kant): our consciousness of ourselves as free agents. The paper brings out Iqbal’s continuity with Kant but also his divergence, in particular his non-Kantian view that we possess a non-sensory intuition of ourselves as free personal causes. It also offer an argument on Iqbal’s behalf for this claim, which is meant as a defense against a Kantian objection to the possibility of intuition of freedom and a skeptic’s challenge to the possibility of freedom in general. Remaining part of the paper offers a reconstruction of Iqbal’s two preconditions of the possibility of free agency. Section 2 discusses the first precondition, namely, the unity of consciousness involved in thought (this is a precondition of agency whether or not it is free). The unity has two aspects, a quantitative (or numerical) aspect and a qualitative (or rational) one. Section 2 offers a defense of these two aspects of the unity of consciousness presupposed by agency by focusing, with Iqbal, on the case of inference.Section 3 discusses a second precondition of the possibility of free agency, that thought and will must be identical in a free agent. Iqbal offers this condition in relief against Bergson’s view. Bergson (on Iqbal’s reading of him) argues that freedom of the will is possible only if the will’s ends are entirely its own and are wholly undetermined by anything from without, not even by thought. Iqbal observes that Bergson’s position ends in an insurmountable dualism of will and thought. Bergson’s view, Iqbal argues in particular, rests on an untenable conception of what an end consists in. An end, correctly understood, is framed by a thinking faculty, the intellect, and not by an extra-rational faculty. The present section outlines Iqbal’s argument for this claim, which rests on the premise that ends possess a certain unity which is intrinsic to particular ends and holds together different ends, and this unity is none other than the quantitative and qualitative unity of a thinking consciousness but in its practical application. Having secured the rational origin of ends, Iqbal argues that a free will must be identical with thought, or else it will be determined from without and won’t be free on that account. Freedom of the self is not a freedom from thought but a freedom in thought: it involves the ability to live a thoughtful life.

Keywords: iqbal, freedom, will, self

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Authors: Hayden R Schott, John M Felder III

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Introduction: Chronic lower extremity wounds in the diabetic and vasculopathic populations are associated with a high degree of morbidity.When wounds require more extensive treatment than can be offered by wound care centers, more aggressive solutions involve local tissue transfer and microsurgical free tissue transfer for achieving definitive soft tissue coverage. These procedures of autologous tissue transfer (ATT) offer resilient, soft tissue coverage of limb-threatening wounds and confer promising limb salvage rates. However, chronic osteomyelitis and recalcitrant soft tissue infections are common in severe diabetic foot wounds and serve to significantly complicate ATT procedures. Stimulan is a resorbable calcium sulfate antibiotic carrier. The use of stimulan antibiotic beads to treat chronic osteomyelitis is well established in the orthopedic and plastic surgery literature. In these procedures, the beads are placed beneath the skin flap to directly deliver antibiotics to the infection site. The purpose of this study was to quantify the success of Stimulan antibiotic beads in treating recalcitrant infections in patients with diabetic foot wounds receiving ATT. Methods: A retrospective review of clinical and demographic information was performed on patients who underwent ATT with the placement of Stimulan antibiotic beads for attempted limb salvage from 2018-21. Patients were analyzed for preoperative wound characteristics, demographics, infection recurrence, and adverse outcomes as a result of product use. The primary endpoint was 90 day infection recurrence, with secondary endpoints including 90 day complications. Outcomes were compared using basic statistics and Fisher’s exact tests. Results: In this time span, 14 patients were identified. At the time of surgery, all patients exhibited clinical signs of active infection, including positive cultures and erythema. 57% of patients (n=8) exhibited chronic osteomyelitis prior to surgery, and 71% (n=10) had exposed bone at the wound base. In 57% of patients (n=8), Stimulan beads were placed beneath a free tissue flap and beneath a pedicle tissue flap in 42% of patients (n=6). In all patients, Stimulan beads were only applied once. Recurrent infections were observed in 28% of patients (n=4) at 90 days post-op, and flap nonadherence was observed in 7% (n=1). These were the only Stimulan related complications observed. Ultimately, lower limb salvage was successful in 85% of patients (n=12). Notably, there was no significant association between the preoperative presence of osteomyelitis and recurrent infections. Conclusions: The use of Stimulanantiobiotic beads to treat recalcitrant infections in patients receiving definitive skin coverage of diabetic foot wounds does not appear to demonstrate unnecessary risk. Furthermore, the lack of significance between the preoperative presence of osteomyelitis and recurrent infections indicates the successful use of Stimulan to dampen infection in patients with osteomyelitis, as is consistent with the literature. Further research is needed to identify Stimulan as the significant contributor to infection treatment using future cohort and case control studies with more patients. Nonetheless, the use of Stimulan antibiotic beads in patients with diabetic foot wounds demonstrates successful infection suppression and maintenance of definitive soft tissue coverage.

Keywords: wound care, stimulan antibiotic beads, free tissue transfer, plastic surgery, wound, infection

Procedia PDF Downloads 90

Authors: Natalie Pomerantz, Nicholas Dugan, Molly Richards, Walter Zukas

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The primary research question to be answered for Chemical/Biological (CB) protective clothing, is how to protect wearers from a range of chemical and biological threats in liquid, vapor, and aerosol form, while reducing the thermal burden. Currently, CB protective garments are hot, heavy, and wearers are limited by short work times in order to prevent heat injury. This study demonstrates how to incorporate different levels of protection on a material level and modify fabric composites such that the thermal burden is reduced to such an extent it approaches that of a standard duty uniform with no CB protection. CB protective materials are usually comprised of several fabric layers: a cover fabric with a liquid repellent coating, a protective layer which is comprised of a carbon-based sorptive material or semi-permeable membrane, and a comfort next-to-skin liner. In order to reduce thermal burden, all of these layers were laminated together to form one fabric composite which had no insulative air gap in between layers. However, the elimination of the air gap also reduced the CB protection of the fabric composite. In order to increase protection in the laminated composite, different nonwoven aerosol protective liners were added, and a super repellent coating was applied to the cover fabric, prior to lamination. Different adhesive patterns were investigated to determine the durability of the laminate with the super repellent coating, and the effect on air permeation. After evaluating the thermal properties, textile properties and protective properties of the iterations of these fabric composites, it was found that the thermal burden of these materials was greatly reduced by decreasing the thermal resistance with the elimination of the air gap between layers. While the level of protection was reduced in laminate composites, the addition of a super repellent coating increased protection towards low volatility agents without impacting thermal burden. Similarly, the addition of aerosol protective liner increased protection without reducing water vapor transport, depending on the nonwoven used, however, the air permeability was significantly decreased. The balance of all these properties and exploration of the trade space between thermal burden and protection will be discussed.

Keywords: aerosol protection, CBRNe protection, lamination, nonwovens, repellent coatings, thermal burden

Procedia PDF Downloads 364

Authors: Shaimaa Eltanani, Thangal Yumnamcha, Ahmed S. Ibrahim

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Purpose: Mitochondria dysfunction is central to breaking the barrier integrity of retinal endothelial cells (RECs) in various blinding eye diseases such as diabetic retinopathy and retinopathy of prematurity. Therefore, we aimed to dissect the role of different mitochondrial components, specifically, those of oxidative phosphorylation (OxPhos), in maintaining the barrier function of RECs. Methods: Electric cell-substrate impedance sensing (ECIS) technology was used to assess in real-time the role of different mitochondrial components in the total impedance (Z) of human RECs (HRECs) and its components; the capacitance (C) and the total resistance (R). HRECs were treated with specific mitochondrial inhibitors that target different steps in OxPhos: Rotenone for complex I; Oligomycin for ATP synthase; and FCCP for uncoupling OxPhos. Furthermore, data were modeled to investigate the effects of these inhibitors on the three parameters that govern the total resistance of cells: cell-cell interactions (Rb), cell-matrix interactions (α), and cell membrane permeability (Cm). Results: Rotenone (1 µM) produced the greatest reduction in the Z, followed by FCCP (1 µM), whereas no reduction in the Z was observed after the treatment with Oligomycin (1 µM). Following this further, we deconvoluted the effect of these inhibitors on Rb, α, and Cm. Firstly, rotenone (1 µM) completely abolished the resistance contribution of Rb, as the Rb became zero immediately after the treatment. Secondly, FCCP (1 µM) eliminated the resistance contribution of Rb only after 2.5 hours and increased Cm without considerable effect on α. Lastly, Oligomycin had the lowest impact among these inhibitors on Rb, which became similar to the control group at the end of the experiment without noticeable effects on Cm or α. Conclusion: These results demonstrate differential roles for complex I, complex V, and coupling of OxPhos in maintaining the barrier functionality of HRECs, in which complex I being the most important component in regulating the barrier functionality and the spreading behavior of HRECs. Such differences can be used in investigating gene expression as well as for screening selective agents that improve the functionality of complex I to be used in the therapeutic approach for treating REC-related retinal diseases.

Keywords: human retinal endothelial cells (hrecs), rotenone, oligomycin, fccp, oxidative phosphorylation, oxphos, capacitance, impedance, ecis modeling, rb resistance, α resistance, and barrier integrity

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Authors: Ivna Mororó, Lise P. Labéjof, Stephanie Ribeiro, Kely Almeida

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Lipid droplets (LDs) are normally presented in greater or lesser number in the cytoplasm of almost all eukaryotic and some prokaryotic cells. They are independent organelles composed of a lipid ester core and a surface phospholipid monolayer. As a lipid storage form, they provide an available source of energy for the cell. Recently it was demonstrated that they play an important role in other many cellular processes. Among the many unresolved questions about them, it is not even known how LDs is formed, how lipids are recruited to LDs and how they interact with the other organelles. Excess fat in the organism is pathological and often associated with the development of some genetic, hormonal or behavioral diseases. The formation and accumulation of lipid droplets in the cytoplasm can be increased by exogenous physical or chemical agents. It is well known that ionizing radiation affects lipid metabolism resulting in increased lipogenesis in cells, but the details of this process are unknown. To better understand the mode of formation of LDs in liver cells, we investigate their ultrastructural morphology after irradiation. For that, Wistar rats were exposed to whole body gamma radiation from 60-cobalt at various single doses. Samples of the livers were processed for analysis under a conventional transmission electron microscope. We found that when compared to controls, morphological changes in liver cells were evident at the higher doses of radiation used. It was detected a great number of lipid droplets of different sizes and homogeneous content and some of them merged each other. In some cells, it was observed diffused LDs, not limited by a monolayer of phospholipids. This finding suggests that the phospholipid monolayer of the LDs was disrupted by ionizing radiation exposure that promotes lipid peroxydation of endo membranes. Thus the absence of the phospholipid monolayer may prevent the realization of some cellular activities as follow: - lipid exocytosis which requires the merging of LDs membrane with the plasma membrane; - the interaction of LDs with other membrane-bound organelles such as the endoplasmic reticulum (ER), the golgi and mitochondria and; - lipolysis of lipid esters contained in the LDs which requires the presence of enzymes located in membrane-bound organelles as ER. All these impediments can contribute to lipid accumulation in the cytoplasm and the development of diseases such as liver steatosis, cirrhosis and cancer.

Keywords: radiobiology, hepatocytes, lipid metabolism, transmission electron microscopy

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Authors: Keshav Prasad Kandel, Balaram Khadka, Karan Bhatta, Basu Dev Ghimire

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Earthquakes still exist as a threating disaster. Being able to predict earthquakes will certainly help prevent substantial loss of life and property. Perhaps, Very Low Frequency/Low Frequency (VLF/LF) signal band (3-30 kHz), which is effectively reflected from D-layer of ionosphere, can be established as a tool to predict earthquake. On May 20 and May 29, 2012, earthquakes of magnitude 6.1 and 5.8 respectively struck Emilia-Romagna of Italy. A year back, on August 24, 2016, an earthquake of magnitude 6.2 struck Central Italy (42.7060 N and 13.2230 E) at 1:36 UT. We present the results obtained from the US Navy VLF Transmitter’s NSY signal of 45.9 kHz transmitted from Niscemi, in the province of Sicily, Italy and received at the Kiel Longwave Monitor, Germany for 2012 and 2016. We analyzed the terminator times, their individual differences and nighttime fluctuation counts. We also analyzed trends, dispersion and nighttime fluctuation which gave us a possible precursors to these earthquakes. Since perturbations in VLF amplitude could also be due to various other factors like lightning, geomagnetic activities (storms, auroras etc.) and solar activities (flares, UV flux, etc.), we filtered the possible perturbations due to these agents to guarantee that the perturbations seen in VLF/LF amplitudes were as a precursor to Earthquakes. As our TRGCP path is North-south, the sunrise and sunset time in transmitter and receiver places matches making pathway for VLF/LF smoother and therefore hoping to obtain more natural data. To our surprise, we found many clear anomalies (as precursors) in terminator times 5 days to 16 days before the earthquakes. Moreover, using night time fluctuation method, we found clear anomalies 5 days to 13 days prior to main earthquakes. This exactly correlates with the findings of previous authors that ionospheric perturbations are seen few days to one month before the seismic activity. In addition to this, we were amazed to observe unexpected decrease of dispersion on certain anomalies where it was supposed to increase, thereby not supporting our finding to some extent. To resolve this problem, we devised a new parameter called dispersion nighttime (dispersion). On analyzing, this parameter decreases significantly on days of nighttime anomalies thereby supporting our precursors to much extent.

Keywords: D-layer, TRGCP (Transmitter Receiver Great Circle Path), terminator times, VLF/LF

Procedia PDF Downloads 191

Authors: Japhet N. Mwambusi

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High tropical forests deforestation for solid wood furniture industry is among of climate change contributing agents. This pressure indirectly is caused by furniture joints failure due to poor gluing technology based on improper use of different glues to different wood species which lead to low quality and weak wood-glue joints. This study was carried in order to run performance tests of wood glues on different wood species used in wood workshops: Morogoro Tanzania whereby three popular wood species of C. lusitanica, T. glandis and E. maidenii were tested against five glues of Woodfix, Bullbond, Ponal, Fevicol and Coral found in the market. The findings were necessary on developing a guideline for proper glue selection for a particular wood species joining. Random sampling was employed to interview carpenters while conducting a survey on the background of carpenters like their education level and to determine factors that influence their glues choice. Monsanto Tensiometer was used to determine bonding strength of identified wood glues to different wood species in use under British Standard of testing wood shear strength (BS EN 205) procedures. Data obtained from interviewing carpenters were analyzed through Statistical Package of Social Science software (SPSS) to allow the comparison of different data while laboratory data were compiled, related and compared by the use of MS Excel worksheet software as well as Analysis of Variance (ANOVA). Results revealed that among all five wood glues tested in the laboratory to three different wood species, Coral performed much better with the average shear strength 4.18 N/mm², 3.23 N/mm² and 5.42 N/mm² for Cypress, Teak and Eucalyptus respectively. This displays that for a strong joint to be formed to all tree wood species for soft wood and hard wood, Coral has a first priority in use. The developed table of guideline from this research can be useful to carpenters on proper glue selection to a particular wood species so as to meet glue-bond strength. This will secure furniture market as well as reduce pressure to the forests for furniture production because of the strong existing furniture due to their strong joints. Indeed, this can be a good strategy on reducing climate change speed in tropics which result from high deforestation of trees for furniture production.

Keywords: climate change, deforestation, gluing technology, joint failure, wood-glue, wood species

Procedia PDF Downloads 240

Authors: Vivek Garg, Brajendra S. Sengar, Gaurav Siddharth, Nisheka Anadkat, Amitesh Kumar, Shailendra Kumar, Shaibal Mukherjee

Abstract:

CuInGaSe (CIGSe) is the dominant thin film solar cell technology. The band alignment of Buffer/CIGSe interface is one of the most crucial parameters for solar cell performance. In this article, the valence band offset (VBOff) and conduction band offset (CBOff) values of Cu(In0.70Ga0.30)Se/ 1 at.% Ga: Mg0.25Zn0.75O (GMZO) heterojunction, grown by dual ion beam sputtering system (DIBS), are calculated to understand the carrier transport mechanism at the heterojunction for the realization of all sputtered buffer-less solar cells. To determine the valence band offset (VBOff), ∆E_V at GMZO/CIGSe heterojunction interface, the standard method based on core-level photoemission is utilized. The value of ∆E_V can be evaluated by considering common core-level peaks. In our study, the values of (Valence band onset)VBOn, obtained by linear extrapolation method for GMZO and CIGSe films are calculated to be 2.86 and 0.76 eV. In the UPS spectra peak positions of Se 3d is observed in UPS spectra at 54.82 and 54.7 eV for CIGSe film and GMZO/CIGSe interface respectively, while the peak position of Mg 2p is observed at 50.09 and 50.12 eV for GMZO and GMZO/CIGSe interface respectively. The optical band gap of CIGSe and GMZO are obtained from absorption spectra procured from spectroscopic ellipsometry are 1.26 and 3.84 eV respectively. The calculated average values of ∆E_v and ∆E_C are estimated to be 2.37 and 0.21 eV, respectively, at room temperature. The calculated positive conduction band offset termed as a spike at the absorber junction is the required criterion for the high-efficiency solar cells for the efficient charge extraction from the junction. So we can conclude that the above study confirms GMZO thin films grown by the dual ion beam sputtering system are the suitable candidate for the CIGSe thin films based ultra-thin buffer-less solar cells. We investigated the band-offset properties at the GMZO/CIGSe heterojunction to verify the suitability of the GMZO for the realization of the buffer-less solar cells. The calculated average values of ∆E_V and ∆E_C are estimated to be 2.37 and 0.21 eV, respectively, at room temperature. The calculated positive conduction band offset termed as a spike at the absorber junction is the required criterion for the high-efficiency solar cells for the efficient charge extraction from the junction. So we can conclude that the above study confirms GMZO thin films grown by the dual ion beam sputtering system are the suitable candidate for the CIGSe thin films based ultra-thin buffer-less solar cells. Acknowledgment: We are thankful to DIBS, EDX, and XRD facility equipped at Sophisticated Instrument Centre (SIC) at IIT Indore. The authors B.S.S and A.K acknowledge CSIR and V.G acknowledge UGC, India for their fellowships. B.S.S is thankful to DST and IUSSTF for BASE Internship Award. Prof. Shaibal Mukherjee is thankful to DST and IUSSTF for BASE Fellowship and MEITY YFRF award. This work is partially supported by DAE BRNS, DST CERI, and DST-RFBR Project under India-Russia Programme of Cooperation in Science and Technology. We are thankful to Mukul Gupta for SIMS facility equipped at UGC-DAE Indore.

Keywords: CIGSe, DIBS, GMZO, solar cells, UPS

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Authors: Samson Viulu, Hugo Hebala, Duddley Kopu

Abstract:

Constituency Development Fund (CDF) is a controversial fund that has existed in the Solomon Islands since the early 90s to date. It is largely controversial because it is directly handled by members of parliament (MPs) of the Solomon Islands legislation chamber. It is commonly described as a political slash fund because only voters of MPs benefit from it to retain loyalty. The CDF was established by a legislative act in 2013; however, it does not have any subsidiary regulations to it, therefore, very weak governance. CDF is purposely to establish development projects in the rural areas of the Solomon Islands to spur economic growth. Although almost USD500M was spent in CDF in the last decade, there has been no growth in the economy of the Solomon Islands; rather, a regress. Solomon Islands has now formulated a first home-grown policy aimed at guiding the overall development of the fifty constituencies, improving delivery mechanisms of the CDF, and strengthening its governance through the regulation of the CDF Act 2013. The Solomon Islands Constituency Development Policy is the first for the country since gaining independence in 1978 and gives strong emphasis on a cross-sectoral approach through effective partnerships and collaborations and decentralizing government services to the isolated rural areas of the country. The new policy is driving the efforts of the political government to decentralize government services to isolated rural communities to encourage the participation of rural dwellers in economic activities. The decentralization will see the establishment of constituency offices within all constituencies and the piloting of townships in constituencies that have met the statutory requirements of the state. It also encourages constituencies to become development agents of the national government than being mere political boundaries. The decentralization will go in line with the establishment of the Solomon Islands Special Economic Zones (SEZ), where investors will be given special privileges and exemptions from government taxes and permits to attract tangible development to occur in rural constituencies. The design and formulation of the new development policy are supported by the UNDP office in the Solomon Islands. The new policy is promoting a reorientation on the allocation of resources more toward the productive and resource sectors, making access to finance easier for entrepreneurs and encouraging growth in rural entrepreneurship in the fields of agriculture, fisheries, down streaming, and tourism across the Solomon Islands. This new policy approach will greatly assist the country to graduate from the least developed countries status in a few years’ time.

Keywords: decentralization, constituency development fund, Solomon Islands constituency development policy, partnership, entrepreneurship

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Authors: Tramuta Clara, Masotti Chiara, Pitti Monica, Adriano Daniela, Battistini Roberta, Serraca Laura, Decastelli Lucia

Abstract:

Oysters are considered filter organisms, and their raw consumption may increase health risks for consumers: it is often associated with outbreaks of gastroenteritis or enteric illnesses. Most of these foodborne diseases are caused by Vibrio strains, enteric pathogens also involved in the diffusion of genetic determinants of antibiotic resistance and their entrance along the food chain. The European Food Safety Authority (EFSA), during the European Union report on antimicrobial resistance in 2017, focused the attention about the role of food as a possible carrier of antibiotic-resistant bacteria or antibiotic-resistance genes that determine health risks for humans. This study wants to determine antibiotic resistance and antibiotic-resistance genes in Vibrio spp. isolated from Crassostrea gigas oysters collected in the Golfo della Spezia (Liguria, Italy). A total of 47 Vibrio spp. strains were isolated (ISO21872-2:2017) during the summer of 2021 from oysters of Crassostrea gigas. The strains were identified by MALDI-TOF (Bruker, Germany) mass spectrometry and tested for antibiotic susceptibility using a broth microdiluition method (ISO20776-1:2019) using Sensititre EUVSEC plates (Thermo-Fisher Scientific) to obtain the Minimum Inhibitory Concentration (MIC). The strains were tested with PCR-based biomolecular methods, according to previous works, to define the presence of 23 resistance genes of the main classes of antibiotics used in human and veterinary medicine: tet (B), tet (C), tet (D), tet (A), tet (E), tet (G ), tet (K), tet (L), tet (M), tet (O), tet (S) (tetracycline resistance); blaCTX-M, blaTEM, blaOXA, blaSHV (β-lactam resistance); mcr-1 and mcr-2 (colistin resistance); qnrA, qnrB, and qnrS (quinolone resistance); sul1, sul2 and sul3 (sulfonamide resistance). Six different species have been identified: V. alginolyticus 34% (n=16), V. harveyi 28% (n=13), V. fortis 15% (n=7), V. pelagius 8% (n=4), V. parahaemolyticus 11% (n=5) e V. chagasii 4% (n=2). The PCR assays showed the presence of the blaTEM gene on 40% of the strains (n=19). All the other genes were not detected, except for a V. alginolyticus positive for anrS gene. The broth microdiluition method results showed an high level of resistance for ciprofloxacin (62%; n=29), ampicillin (47%; n=22), and colistin (49%; n=23). Furthermore, 32% (n=15) of strains can be considered multiresistant bacteria for the simultaneous presence of resistance for three different antibiotic classes. Susceptibility towards meropenem, azithromycin, gentamicin, ceftazidime, cefotaxime, chloramphenicol, tetracycline and sulphamethoxazole reached 100%. The Vibrio species identified in this study are widespread in marine environments and can cause gastrointerstinal infections after the ingestion of raw fish products and bivalve molluscs. The level of resistance to antibiotics such as ampicillin, ciprofloxacin and colistin can be connected to anthropic factors (industrial, agricultural and domestic wastes) that promote the spread of resistance to these antibiotics. It can be also observed a strong correlation between phenotypic (resistant MIC) and genotypic (positive blaTEM gene) resistance for ampicillin on the same strains, probably due to the transfer of genetic material between bacterial strains. Consumption of raw bivalve molluscs can represent a risk for consumers heath due to the potentially presence of foodborne pathogens, highly resistant to different antibiotics and source of transferable antibiotic-resistant genes.

Keywords: vibrio species, blaTEM genes, antimicrobial resistance, PCR

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