Search results for: fatty acid composition

Authors: Iñaki Iturria, Pasquale Russo, Montserrat Nacher-Vázquez, Giuseppe Spano, Paloma López, Miguel Angel Pardo

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Introduction: It is known that some Lactic Acid Bacteria (LAB) present an interesting probiotic effect. Probiotic bacteria stimulate host resistance to microbial pathogens and thereby aid in immune response, and modulate the host's immune responses to antigens with a potential to down-regulate hypersensitivity reactions. Therefore, probiotic therapy is valuable against intestinal infections and may be beneficial in the treatment of Inflammatory Bowel Disease (IBD). Several in vitro tests are available to evaluate the probiotic potential of a LAB strain. However, an in vivo model is required to understand the interaction between the host immune system and the bacteria. During the last few years, zebrafish (Danio rerio) has gained interest as a promising vertebrate model in this field. This organism has been extensively used to study the interaction between the host and the microbiota, as well as the host immune response under several microbial infections. In this work, we report on the use of the zebrafish model to investigate in vivo the colonizing ability and the immunomodulatory effect of probiotic LAB. Methods: Lactobacillus strains belonging to different LAB species were fluorescently tagged and used to colonize germ-free zebrafish larvae gastrointestinal tract (GIT). Some of the strains had a well-documented probiotic effect (L. acidophilus LA5); while others presented an exopolysaccharide (EPS) producing phenotype, thus allowing evaluating the influence of EPS in the colonization and immunomodulatory effect. Bacteria colonization was monitored for 72 h by direct observation in real time using fluorescent microscopy. CFU count per larva was also evaluated at different times. The immunomodulatory effect was assessed analysing the differential expression of several innate immune system genes (MyD88, NF-κB, Tlr4, Il1β and Il10) by qRT- PCR. The anti-inflammatory effect was evaluated using a chemical enterocolitis zebrafish model. The protective effect against a pathogen was also studied. To that end, a challenge test was developed using a fluorescently tagged pathogen (Vibrio anguillarum-GFP+). The progression of the infection was monitored up to 3 days using a fluorescent stereomicroscope. Mortality rates and CFU counts were also registered. Results and conclusions: Larvae exposed to EPS-producing bacteria showed a higher fluorescence and CFU count than those colonized with no-EPS phenotype LAB. In the same way, qRT-PCR results revealed an immunomodulatory effect on the host after the administration of the strains with probiotic activity. A downregulation of proinflammatory cytoquines as well as other cellular mediators of inflammation was observed. The anti-inflammatory effect was found to be particularly marked following exposure to LA% strain, as well as EPS producing strains. Furthermore, the challenge test revealed a protective effect of probiotic administration. As a matter of fact, larvae fed with probiotics showed a decrease in the mortality rate ranging from 20 to 35%. Discussion: In this work, we developed a promising model, based on the use of gnotobiotic zebrafish coupled with a bacterial fluorescent tagging in order to evaluate the probiotic potential of different LAB strains. We have successfully used this system to monitor in real time the colonization and persistence of exogenous LAB within the gut of zebrafish larvae, to evaluate their immunomodulatory effect and for in vivo competition assays. This approach could bring further insights into the complex microbial-host interactions at intestinal level.

Keywords: gnotobiotic, immune system, lactic acid bacteria, probiotics, zebrafish

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Authors: Mulatu Kassie Birhanu

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Electrochemical reduction of CO₂ is an emerging and current issue for its conversion in to valuable product upon minimization of its atmospheric level for contribution of maintaining within the range of permissible limit. Among plenty of electro-catalysts gold and copper are efficient and effective catalysts, which are synthesized and applicable for this research work. The two metal catalysts were prepared in inert environment with different compositions through co-reduction process from their corresponding precursors and then by adding multi-walled carbon nano-tube as a supporter and enhanced the conductivity. The catalytic performance of CO₂ reduction for each composition was performed and resulted an outstanding catalytic activity with generation of high current density (70 mA/cm² at 0.91V vs. RHE) and relatively small onset potential. The catalytic performance, compositions, morphologies, structure and geometric arrangements were evaluated by electrochemical analysis (LSV, impedance, chronoamperometry & tafel plot), EDS, SEM and XAS respectively. The composite metals showed better selectivity of products and faradaic efficiencies due to the synergetic effects of the combined nano-particles in addition to the impact of grain size in reduction of CO₂. Carbon monoxide, hydrogen, formate and ethanol are the reduction products, which are detected and quantifiable by chromatographic techniques considering their physical state of each product.

Keywords: carbondioxide, faradaic efficiency, electrocatalyst, current density

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Authors: M. Michael Gromiha, A. Mary Thangakani, Sandeep Kumar, D. Velmurugan

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The main cause of several neurodegenerative diseases such as Alzhemier, Parkinson, and spongiform encephalopathies is formation of amyloid fibrils and plaques in proteins. We have analyzed different sets of proteins and peptides to understand the influence of sequence-based features on protein aggregation process. The comparison of 373 pairs of homologous mesophilic and thermophilic proteins showed that aggregation-prone regions (APRs) are present in both. But, the thermophilic protein monomers show greater ability to ‘stow away’ the APRs in their hydrophobic cores and protect them from solvent exposure. The comparison of amyloid forming and amorphous b-aggregating hexapeptides suggested distinct preferences for specific residues at the six positions as well as all possible combinations of nine residue pairs. The compositions of residues at different positions and residue pairs have been converted into energy potentials and utilized for distinguishing between amyloid forming and amorphous b-aggregating peptides. Our method could correctly identify the amyloid forming peptides at an accuracy of 95-100% in different datasets of peptides.

Keywords: aggregation, amyloids, thermophilic proteins, amino acid residues, machine learning techniques

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Authors: Priti Rani, Rajni Johar, P. S. Jassal

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The magnetic chitosan beads (MCB) were synthesized using co-precipitation method and made to react with epichlorohydrin (ECH) to get the cross-linked derivative (ECH-MCB). The beads were characterized by FTIR, SEM, EDX, and TGA. It is found that zinc metal ion sorption efficiency of ECH-MCB is significantly higher than MCB. Various factors affecting the uptake behavior of metal ions, such as pH, adsorbent dosage, contact time, and temperature effects, were investigated. The adsorption parameters fitted well with Langmuir and Freundlich isotherms. The equilibrium parameter RL values support that the adsorption (0 < RL < 1) is favorable and spontaneous process. The thermodynamic parameters confirm that it is an endothermic reaction, which results in an increase in the randomness of adsorption process. The beads were regenerated using ethylene diamine tetraacetic acid (EDTA) for further use. These beads prove as promising materials for the removal of pollutants from industrial wastewater. Water samples from Yamuna and Hindon rivers were analysed for the detection of Zn (II) ions.

Keywords: chitosan magnetic beads, EDTA, epichlorohydrin, removal efficiency

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Authors: Apoorva Vinod, Archana Mathur, Snehanshu Saha

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Though there exists a plethora of Activation Functions (AFs) used in single and multiple hidden layer Neural Networks (NN), their behavior always raised curiosity, whether used in combination or singly. The popular AFs –Sigmoid, ReLU, and Tanh–have performed prominently well for shallow and deep architectures. Most of the time, AFs are used singly in multi-layered NN, and, to the best of our knowledge, their performance is never studied and analyzed deeply when used in combination. In this manuscript, we experiment with multi-layered NN architecture (both on shallow and deep architectures; Convolutional NN and VGG16) and investigate how well the network responds to using two different AFs (Sigmoid-Tanh, Tanh-ReLU, ReLU-Sigmoid) used alternately against a traditional, single (Sigmoid-Sigmoid, Tanh-Tanh, ReLUReLU) combination. Our results show that using two different AFs, the network achieves better accuracy, substantially lower loss, and faster convergence on 4 computer vision (CV) and 15 Non-CV (NCV) datasets. When using different AFs, not only was the accuracy greater by 6-7%, but we also accomplished convergence twice as fast. We present a case study to investigate the probability of networks suffering vanishing and exploding gradients when using two different AFs. Additionally, we theoretically showed that a composition of two or more AFs satisfies Universal Approximation Theorem (UAT).

Keywords: activation function, universal approximation function, neural networks, convergence

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Authors: Akwu A. Nneka, Naidoo, Yougasphree

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A significantly high number of microbes exist in higher plants; these microbes include bacteria, fungi, and actinomycetes. There are reports on the benefits of endophytic fungi and their products of metabolism to the host plant and man, consequently, it is expedient to explore the changes that could arise as a result of manipulating their growth media. Grewia lasiocarpa E. Mey. ex Harv. (Malvaceae) is an indigenous Southern African plant, that belongs to a genus with known medicinal properties. Three media were used to culture the endophytic fungi viz., Potato Dextrose Agar (PDA), Malt Extract Agar (MEA), and Bacteriological Agar (BA) were used singly, and supplemented with three dilutions of the leaves and stem bark extracts. The manipulated growth media composition had a significant effect on the diversity of the isolated fungal populations. Several endophytic fungi were isolated; their distribution and diversity revealed a significant relatedness with the manipulated media. The media supplemented with the plant extracts was observed to give a significant increase in the growth rate and yield of the endophytes. To the best of our knowledge, this is the first study describing the endophytic fungi present in the leaves and stem bark of G. lasiocarpa E. Mey. ex Harv.

Keywords: Grewia lasiocarpa, plant-based extracts, endophytic fungi, Malvaceae

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Authors: Yingjeng James Li, Chih Chi Hsu, Chiao-Chih Hu

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Membrane electrode assemblies MEAs for proton exchange membrane PEM water electrolyzers were prepared by employing 175um perfluorosulfonic acid PFSA membranes as the PEM, onto which iridium oxide catalyst was coated on one side as the anode and platinum catalyst was coated on the other side as the cathode. The cathode catalyst ink was prepared so that the weight ratio of the catalyst powder to ionomer was 75:25, 70:30, 65:35, 60:40, and 55:45, respectively. Whereas, the ratio of catalyst powder to ionomer of the anode catalyst ink keeps constant at 50:50. All the MEAs have a catalyst coated area of 5cm*5cm. The test cell employs a platinum plated titanium grid as anode gas diffusion media; whereas, carbon paper was employed as the cathode gas diffusion media. The measurements of the MEA gases production rate were carried out by holding the cell voltage ranging from 1.6 to 2.8 volts at room temperature. It was found that the MEA with cathode catalyst to ionomer ratio of 65:35 gives the largest hydrogen production rate which is 2.8mL/cm2*min.

Keywords: electrolyzer, membrane electrode assembly, proton exchange membrane, ionomer, hydrogen

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Authors: Nabia Siddiqui, Tahira Mohsin Ali, Tanveer Abbas, Abid Hasnain

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The present study proposed the use of different onion peel extracts in a South Asian snacks called ‘sew’. The polyphenols extracted from peels were initially analyzed for their antimicrobial potential and bioactive components following three different extraction systems. A relatively higher level of total phenolic content (TP), total flavonoid (TF) and antioxidant activity was observed for EWE (ethanol and water based) extracts followed by EAAE (ethanol and acetic acid) and WE (water extract) sample. Onion extracts showed ability to inhibit gram-positive as well as gram-negative bacteria. The incorporation of onion peel extracts in sew showed a marked increase in bioactive components. Besides bioactivity, sensory attributes, textural characteristics and storage stability of these snacks containing onion peel extract also significantly improved during the shelf study at ambient temperature for up to two months. Thus, these results justify the utilization of these plant polyphenols in fried snacks.

Keywords: onion peels extract, South Asian snacks, antioxidant capacity, bioactivity

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Authors: Rakesh Choudhary, Ajay Kumar, Deepak Sharma

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The main goal of this paper is to investigate the challenges and benefits of IoT integration in biogas production. This overview explains how the inclusion of IoT can enhance biogas production efficiency. Therefore, such collected data can be explored by advanced analytics, including Artificial intelligence (AI) and Machine Learning (ML) algorithms, consequently improving bio-energy processes. To boost biogas generation efficiency, this report examines the use of IoT devices for real-time data collection on key parameters, e.g., pH, temperature, gas composition, and microbial growth. Real-time monitoring through big data has made it possible to detect diverse, complex trends in the process of producing biogas. The Informed by advanced analytics can also help in improving bio-energy production as well as optimizing operational conditions. Moreover, IoT allows remote observation, control and management, which decreases manual intervention needed whilst increasing process effectiveness. Such a paradigm shift in the incorporation of IoT technologies into biogas production systems helps to achieve higher productivity levels as well as more practical biomass quality biomethane through real-time monitoring-based proactive decision-making, thus driving continuous performance improvement.

Keywords: internet of things, biogas, renewable energy, sustainability, anaerobic digestion, real-time monitoring, optimization

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Authors: Yaser Maher Abdelaziz Hawa

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The Basic-ultrabasic rocks of Bou Azzer ophiolite complex in the Anti-atlas , Morrocco enclose some oxide and sulfide minerals as dissiminated traces. The oxide minerals show a wide variation in composition ranging from Cr-free. Titanomagnetite and ilmenite in the chilled margin gabbro of the upper part of the ophiolite sequence to Al-rich chromian spinel and pure magnetite enclosed in the serpentinized peridotite in the lower part of the sequence. Five mineral assemblages have been distinguished depending on the rock type of the ophiolite sequence. 1-Gersodorfite + Chalcopyrite + Al-Mg rich chromian spinel + pure magnetite, hosted by serpentinized peridotite. 2- Pyrite + Chalcopyrite, enclosed in metagabbro and overlying the ultrabasic cumulates. 3- Al-Fe rich Chromian spinel with rims of Al –rich chromian magnetite enclosed in wherlite. 4- Titanomagnetite replaced by sphene enclosed in marginal Gabbro. 5- Pyrrhotite exsolving Pentlandite + ilmenite + Ilmenite + Al- rich Chromian spinel + magnetite enclosed in fresh olivine olivine in the upper part of the ophiolite sequence.

Keywords: opaques, ophiolites, anti-atlas, morrocco

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Authors: Nazanin Nikanmajd

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Microorganisms are essential for influencing environmental processes, such as nutrient cycling, pollutant breakdown, and ecosystem well-being. Recent developments in high-throughput sequencing technologies and metagenomic methods have given us fresh understandings about the range and capabilities of microorganisms in different settings. This research examines how environmental stressors like climate change, pollution, and habitat degradation affect the composition and roles of microbial communities in soil and water ecosystems. We show that human-caused disruptions change the makeup of microbial communities, causing changes in important metabolic pathways for biogeochemical processes. More precisely, we pinpoint important microbial groups that show resistance or susceptibility to certain stress factors, emphasizing their possible uses in bioremediation and ecosystem rehabilitation. The results highlight the importance of adopting a holistic approach to comprehend microbial changes in evolving environments, impacting sustainable environmental conservation and management strategies. This research helps develop new solutions to reduce the impacts of environmental degradation on microbial ecosystem services by understanding the intricate relationships between microorganisms and their surroundings.

Keywords: environmental microbiology, microbial communities, climate change, pollution, bioremediation, metagenomics, ecosystem services, ecosystem restoration

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Authors: Sadek Salah

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The determination of the strength characteristics of waste materials is essential when evaluating the stability of waste fills during initial placement and at the time of closure and rehabilitation of the landfill. Significant efforts, mostly experimental, have been deployed to date in attempts to quantify the mechanical properties of municipal wastes various stages of decomposition. Even though the studies and work done so far have helped in setting baseline parameters and characteristics for waste materials, inherent concerns remain as to the scalability of the findings between the laboratory and the field along with questions as to the suitability of the actual test conditions. These concerns are compounded by the complexity of the problem itself with significant variability in composition, placement conditions, and levels of decay of the various constituents of the waste fills. A complimentary, if not necessarily an alternative approach is to rely on field observations of behavior and instability of such materials. This paper describes an effort at obtaining relevant shear strength parameters from back-analyses of failures which have been observed at a major un-engineered waste fill along the Mediterranean shoreline. Results from the limit-equilibrium failure back-analyses are presented and compared to results from laboratory-scale testing on comparable waste materials.

Keywords: solid waste, shear strength, landfills, slope stability

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Authors: Babatunde Stephen Oladeji, Gloria Asuquo Edet

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The proximate, functional, pasting, and sensory properties of semolina from blends of cassava, maize, and rice were investigated. Cassava, maize, and rice were milled and sieved to pass through a 1000 µm sieve, then blended in the following ratios to produce five samples; FS₁ (40:30:30), FS₂ (20:50:30), FS₃ (25:25:50), FS₄ (34:33:33) and FS₅ (60:20:20) for cassava, maize, and rice, respectively. A market sample of wheat semolina labeled as FSc served as the control. The proximate composition, functional properties, pasting profile, and sensory characteristics of the blends were determined using standard analytical methods. The protein content of the samples ranged from 5.66% to 6.15%, with sample FS₂ having the highest value and being significantly different (p ≤ 0.05). The bulk density of the formulated samples ranged from 0.60 and 0.62 g/ml. The control (FSc) had a higher bulk density of 0.71 g/ml. The water absorption capacity of both the formulated and control samples ranged from 0.67% to 2.02%, with FS₃ having the highest value and FSc having the lowest value (0.67%). The peak viscosity of the samples ranged from 60.83-169.42 RVU, and the final viscosity of semolina samples ranged from 131.17 to 235.42 RVU. FS₅ had the highest overall acceptability score (7.46), but there was no significant difference (p ≤ 0.05) from other samples except for FS₂ (6.54) and FS₃ (6.29). This study establishes that high-quality and consumer-acceptable semolina that is comparable to the market sample could be produced from blends of cassava, maize, and rice.

Keywords: semolina, gluten, celiac disease, wheat allergies

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Authors: Jyh-Ping Chen, Yu-Tin Lai

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Wound healing is a complicated process involving overlapping hemostasis, inflammation, proliferation, and maturation phases. Ideal wound dressings can replace native skin functions in full thickness skin wounds through faster healing rate and also by reducing scar formation. Poly(lactic-co-glycolic acid) (PLGA) is an U.S. FDA approved biodegradable polymer to be used as ideal wound dressing material. Several in vitro and in vivo studies have demonstrated the effectiveness of curcumin in decreasing the release of inflammatory cytokines, inhibiting enzymes associated with inflammations, and scavenging free radicals that are the major cause of inflammation during wound healing. Heparin has binding affinities to various growth factors. With the unique and beneficial features offered by those molecules toward the complex process of wound healing, we postulate a composite wound dressing constructed from PLGA, curcumin and heparin would be a good candidate to accelerate scarless wound healing. In this work, we use electrospinning to prepare curcumin-loaded aligned PLGA nanofibrous membranes (PC NFMs). PC NFMs were further subject to oxygen plasma modification and surfaced-grafted with heparin through carbodiimide-mediated covalent bond formation to prepare curcumin-loaded PLGA-g-heparin (PCH) NFMs. The nanofibrous membranes could act as three-dimensional scaffolds to attract fibroblast migration, reduce inflammation, and increase wound-healing related growth factors concentrations at wound sites. From scanning electron microscopy analysis, the nanofibers in each NFM are with diameters ranging from 456 to 479 nm and with alignment angles within  0.5°. The NFMs show high tensile strength and good water absorptivity and provide suitable pore size for nutrients/wastes transport. Exposure of human dermal fibroblasts to the extraction medium of PC or PCH NFM showed significant protective effects against hydrogen peroxide than PLGA NFM. In vitro wound healing assays also showed that the extraction medium of PCH NFM showed significantly better migration ability toward fibroblasts than PC NFM, which is further better than PLGA NFM. The in vivo healing efficiency of the NFMs was further evaluated by a full thickness excisional wound healing diabetic rat model. After 14 days, PCH NFMs exhibits 86% wound closure rate, which is significantly different from other groups (79% for PC and 73% for PLGA NFM). Real-time PCR analysis indicated PC and PCH NFMs down regulated anti-oxidative enzymes like glutathione peroxidase (GPx) and superoxide dismutase (SOD), which are well-known transcription factors involved in cellular inflammatory responses to stimuli. From histology, the wound area treated with PCH NFMs showed more vascular lumen formation from immunohistochemistry of α-smooth muscle actin. The wound site also had more collagen type III (65.8%) expression and less collagen type I (3.5%) expression, indicating scar-less wound healing. From Western blot analysis, the PCH NFM showed good affinity toward growth factors from increased concentration of transforming growth factor-β (TGF-β) and fibroblast growth factor-2 (FGF-2) at the wound site to accelerate wound healing. From the results, we suggest PCH NFM as a promising candidate for wound dressing applications.

Keywords: Curcumin, heparin, nanofibrous membrane, poly(lactic-co-glycolic acid) (PLGA), wound dressing

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Authors: S. Adiloğlu, K. Bellitürk, Y. Solmaz, A. Adiloğlu

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The aim of this research is to remediation of the cadmium (Cd) pollution in agricultural soils by using barley (Hordeum vulgare L.) plant. For this purpose, a pot experiment was done in greenhouse conditions. Cadmium (100 mg/kg) as CdSO₄.8H₂O forms was applied to each pot and incubated during 30 days. Then Ethylenediamine tetraacetic acid (EDTA) chelate was applied to each pot at five doses (0, 3, 6, 8 and 10 mmol/kg) 20 days before harvesting time of the barley plants. The plants were harvested after two months planting. According to the pot experiment results, Cd and Zn amounts of barley plant increased with increasing EDTA application and Zn and Cd contents of barley 20,13 and 1,35 mg/kg for 0 mmol /kg EDTA; 58,61 and 113,24 mg/kg for 10 mmol/kg EDTA doses, respectively. On the other hand, Cd and Zn concentrations of experiment soil increased with EDTA application to the soil samples. Zinc and Cd concentrations of soil 0,31 and 0,021 mg/kg for 0 mmol /kg EDTA; 2,39 and 67,40 mg/kg for 10 mmol/kg EDTA doses, respectively. These increases were found to be statistically significant at the level of 1 %. According to the results of the pot experiment, some heavy metal especially Cd pollution of barley (Hordeum vulgare L.) plant province can be remediated by the phytoextraction method.

Keywords: Barley, Hordeum vulgare L., cadmium, zinc, phytoextraction, soil pollution

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Authors: Nawel Ganaoui, Chadli Souhila, Gahdab Chakal

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This study presents the results of a comparative research aiming to examine the distribution of beetles in four agroecosystems in the Tiaret region, located in northwestern Algeria, during the year 2023. This study was initiated across 04 stations that were randomly distributed within the Ksar Chellala region and selected based on their plant composition. The sampling method used was based on pitfall traps, which were filled two-thirds with a solution of saltwater supplemented with vinegar. In total, 40 species of beetles belonging to 9 families were identified. Among them, tenebrionids were the most abundant group (43%), followed by scarab beetles (30%) The comparison between the four types of agroecosystems - olive culture, sheep farming, cereal cultivation, and Pomegranate cultivation- in this region revealed that cereal cultivation harbored the greatest species diversity (30 species), followed by the sheep farming site (32 species), and then the other sites based on their ecological importance and trophic interactions, these beetle species were mainly categorized as coprophages, phytophages, and predators. The spatiotemporal evolution of beetle activity highlighted peaks of rich-ness and abundance, mainly during the dry period (from April to May), while the cold period (January) showed the low-est levels. The specific diversity of beetles varied significantly from one habitat to another.

Keywords: agroecosystem, beetle, entomology, steppe regoin

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Authors: Haitham Qaralleh, Syed Z. Idid, Shahbudin Saad, Deny Susanti, Osama Althunibat

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This study was carried out to isolate the active antimicrobial compounds from Neopetrosia exigua using bio-guided assay isolation against Staphylococcus aureus. N. exigua was extracted using methanol and subjected to liquid-liquid extraction using solvents with different polarity (n-hexane, carbon tetrachloride, dichloromethane, n-butanol and water). Purification of the active components of n-butanol and dichloromethane fractions was done using Sephadex LH-20 and reverse phase chromatography. Based on the biological guided fractionation results, dichloromethane and n-butanol fractions showed the highest antimicrobial activity. Purification of the active components of n-butanol and dichloromethane fractions yielded three compounds. The structure of the isolated compounds were elucidated and found to be 5-hydroxy-1H-indole-3-carboxylic acid methyl ester, cyclo-1`-demethylcystalgerone and avarol derivative. Avarol was showed potent bactericidal effect against S. aureus. N. exigua appears to be rich source of natural antimicrobial agents. Further studies are needed to investigate the mode of action of these compounds.

Keywords: antimicrobial, avarol, Neopetrosia exigua, Staphylococcus aureus

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Authors: Chol Min Yu, Sok Chol Ri

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The optimization of formation and growth of metallic nuggets during self-reduction of coal composite briquette (CCB here) is essential to increase the yield of valuable metals. The formation of metallic nuggets was investigated theoretically and experimentally during the reduction of coal composite briquette made from stainless steel dust and coal. The formation of metallic nuggets is influenced by slag viscosity and interfacial tension between the liquid metal and the slag in the reduced product. Surface tensions of liquid metal and slag are rather strong, respectively, due to the high basicity of its slag. Strong surface tensions of them lead to increase of interfacial tension between the liquid metal and the slag to be favorable to the growth of metallic nuggets. The viscosity of slag and interfacial tension between the liquid metal and the slag depends on the temperature and composition of the slag. The formation and the growth of metallic nuggets depend on carbon to oxygen ratio FC/O and temperature.

Keywords: stainless steel dust, coal-composite briquette, temperature, high basicity, interfacial tension

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Authors: E. G. Zaki, M. A. Migahed, A. M. Al-Sabagh, E. A. Khamis

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Inhibition effect of four novel nonionic surfactants based on sulphonamide, of linear alkyl benzene sulphonic acid (LABS), was reacted with 1 mole triethylenetetramine, tetraethylenepentamine then Ethoxylation of amide X 65 type carbon steel in oil wells formation water under H2S environment was investigated by electrochemical measurements. Scanning electron microscopy (SEM) and energy dispersion X-ray (EDX) were used to characterize the steel surface. The results showed that these surfactants act as a corrosion inhibitor in and their inhibition efficiencies depend on the ethylene oxide content in the system. The obtained results showed that the percentage inhibition efficiency (η%) was increased by increasing the inhibitor concentration until the critical micelle concentration (CMC) reached The quantum chemistry calculations were carried out to study the molecular geometry and electronic structure of obtained derivatives. The energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital has been calculated using the theoretical computations to reflect the chemical reactivity and kinetic stability of compounds.

Keywords: corrosion, surfactants, steel surface, quantum

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Authors: Abhijith N. V., Abhijit Pattnayak, Deepak Kumar

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Nowadays, a group of alloys, namely high entropy alloys (HEA), because of their excellent properties. However, the fabrication of HEAs requires multistage techniques, especially mill-ing, sieving, compaction, sintering, inert media, etc. These processes are laborious, costly, time-oriented, and unsuitable for commercial application. This study adopted a single-stage process-based HVOF thermal spray to develop HEA coating on SS304L substrates. The wear behavior of the deposited HEA coating was explored under different milling time durations (5h, 10h, and 15h, respectively). The effect of feedstock preparation, microstructure, surface chemistry, and mechanical and metallurgical properties on wear resistance was also investigated. The microstructure and composition of both coating and feedstock were evaluated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis. Finally, the phase distribution was correlated by X-ray diffraction (XRD ) analysis. The results showed that 15h milled powder coating indicated better tribological than the base substrate and 5h,10h milled powder coating. A chemically stable Body Centered Cubic (BCC) solid solution phase was generated within the 15h milled powder-coated system, which resulted in superior tribological properties.

Keywords: high entropy alloys coating, wear mechanism, HVOF coating, microstructure

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Authors: J. Satya Eswari, Ch. Venkateswarlu

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The formulation of a commercial pharmaceutical product involves several composition factors and response characteristics. When the formulation requires to satisfy multiple response characteristics which are conflicting, an optimal solution requires the need for an efficient multiobjective optimization technique. In this work, a regression is combined with a non-dominated sorting differential evolution (NSDE) involving Naïve & Slow and ε constraint techniques to derive different multiobjective optimization strategies, which are then evaluated by means of a trapidil pharmaceutical formulation. The analysis of the results show the effectiveness of the strategy that combines the regression model and NSDE with the integration of both Naïve & Slow and ε constraint techniques for Pareto optimization of trapidil formulation. With this strategy, the optimal formulation at pH=6.8 is obtained with the decision variables of micro crystalline cellulose, hydroxypropyl methylcellulose and compression pressure. The corresponding response characteristics of rate constant and release order are also noted down. The comparison of these results with the experimental data and with those of other multiple regression model based multiobjective evolutionary optimization strategies signify the better performance for optimal trapidil formulation.

Keywords: pharmaceutical formulation, multiple regression model, response surface method, radial basis function network, differential evolution, multiobjective optimization

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Authors: Akshita Bhardwaj

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Keratinase is an enzyme obtained from extracellular sources that is involved in biodegradation of keratin. It is a member of a group of proteases that can break down keratin into amino acids. Keratinases are produced only in the presence of substrate that contain keratin. It attacked the disulfide bond of substrate and involve in keratin degradation. Human hair, feathers, animal hard tissues, horns, claws, and hooves all contain keratin.. It exists in two form alpha keratin (found in soft tissues) and beta keratin (found in hard tissue). By taking part in the degradation of keratin, keratinases derived from microbial sources, often referred to as microbial keratinases, are important in the process of turning wastes containing keratin into products with added value. Chicken feathers contain high level of keratin protein content than other sources and became a suitable protein source. Keratinase production occurs at near alkaline pH and thermophilic temperatures. The bioprocessing of keratinous waste benefits greatly from the use of keratinases. Additionally, it lessens the issue caused by poultry excrement. The use of feather meal, along with keratinase, improves the digestion of proteins and amino acids.

Keywords: mili litre (ml), micro litre (Ul), TCA - trichloroacetic acid, OD - optical density

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Authors: Abhilasha Mishra, Neha Bhatt

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Super-hydrophobicity is an effect in which a surface roughness and chemical composition are combined to produce unusual water and dust repellent surface. The super-hydrophobic surface is widely used in many applications such as windshields of the automobile, aircraft, lens, solar cells, roofing, boat hull, paints, etc. Four coating solutions were prepared by varying compositions of 1,1,1,3,3,3 hexametyldisilazane (HDMS) and tetraethylorthosilicate (TEOS) sol. These solutions were coated on glass slides by a spin coating method and etched at a high temperature ranging 250 -350 oC. All the coatings were studied for its different properties like water repellent, anti-dust, and transparency and contact angle measurements. Stability of coatings was also studied with respect to temperature, external environment, and pH. It was found that all coatings impart a significant super-hydrophobicity on a glass surface with contact angle ranging from 156o to 162o and have good stability in the external environment. The results of the different coatings were observed and compared with each other. On increasing layers of coatings the super-hydrophobicity and anti-dust properties increases but after 3 coatings the transparency of coating starts decreasing.

Keywords: super-hydrophobic, contact angle, coating, anti-dust

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Authors: U. V. Okpala, C. C. Okpala

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The effect of generator exhaust fumes on air, a case study of Onitsha was considered in this work. A sample of 400 respondents was randomly chosen in the study area based on the population. Questionnaire was designed and administered to inhabitants of the study area to enable the researchers ascertain information on the effect of generator exhaust fumes on air and possible remedies. The issue of the types of generators owned by residents, quantity of fuel products purchased per day and the number of years of generator ownership were discussed. The Pearson’s product moment analysis correlation and Chi-square test were applied in the hypothesis testing. The result shows that huge amount of effluents are discharged on the environment thereby polluting the air. This leads to radiative forcing, depletion of ozone layer and precipitation of acid rain. This has untold effect on the climate system. To ensure proper recovery, the study recommends that government makes available alternative energy sources in addition to the conventional power to save the environment; with this, waste becomes wealth towards a sustainable economy in Nigeria.

Keywords: Onitsha, generator, fuel products, exhaust fumes and remedies, energy systems

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Authors: Al-Bogami Abdullah Saad

Abstract:

We reported the environmental benign synthesis of chalcones, 2-pyrazolines and cyclohexanones under microwave irradiation. Chalcones were obtained by the condensation of each of 2-hydroxyacetophenone derivatives with α-naphthaldehyde under microwave irradiation. The condensation reactions of each of synthesized chalcones with phenyl hydrazine under microwave irradiation in the presence of dry acetic acid as a cyclizing agent gave 2-pyrazolines. Also, the new cyclohexenone derivatives, valuable intermediates to synthesize fused heterocycles, have been prepared by the cyclocondensation of each of hydroxychalcones with ethyl acetoacetate. The structures of the synthesized compounds were elucidated by Infrared (IR) spectrometry, Nuclear Magnetic Resonance (NMR), Mass Spectrometry(MS) and elmental analysis. The results indicate that unlike classical heating, microwave irradiation results in higher yields with shorter and cleaner reactions. The synthesized compounds were screened for antimicrobial activity against Staphylococcus aureus, Escherichia coli, Candida Albicans and Aspergillus niger. We clarified the effects of different substituents in the tested compounds on the obtaind antibacterial activities and antifungal activities.

Keywords: microwave irradiation, 2-Hydroxyacetophenone, α-Naphthaldehyde, pyrazoline, cyclohexenone, antimicrobial activity

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Authors: Xiaodong Xu, Dan Zhao, Xiujuan Chang, Chunming Li, Huiyun Zhou, Xin Li, Qiang Shi, Shifang Luan, Jinghua Yin

Abstract:

Polypropylene (PP) is one of the most commonly used plastics because of its low density, outstanding mechanical properties, and low cost. However, its drawbacks such as low surface energy, poor dyeability, lack of chemical functionalities, and poor compatibility with polar polymers and inorganic materials, have restricted the application of PP. To expand its application in biomedical materials, functionalization is considered to be the most effective way. In this study, PP was functionalized with a chiral monomer, (S)-1-acryloylpyrrolidine-2-carboxylic acid ((S)-APCA), by free-radical grafting in the solid phase. The grafting degree of PP-g-APCA was determined by chemical titration method, and the chemical structure of functionalized PP was characterized by FTIR spectroscopy, which confirmed that the chiral monomer (S)-APCA was successfully grafted onto PP. Static water contact angle results suggested that the surface hydrophilicity of PP was significantly improved by solid phase grafting and assistance of surface water treatment. Protein adsorption and platelet adhesion results showed that hemocompatibility of PP was greatly improved by grafting the chiral monomer.

Keywords: functionalization, polypropylene, chiral monomer, hemocompatibility

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Authors: Chanasit Chaocharoenphat

Abstract:

Hibiscus sabdariffa is a herbal plant that is commonly used for home remedies in Thailand. This study aims to determine the antioxidant activity of polyphenols, as oxidative stress plays a vital role in the development of cancer, and H. sabdariffa was used in this study. The total flavonoids content was determined using the aluminium chloride colourimetric method and expressed as quercetin equivalents (QE)/g and the antioxidant capacity of the flavonoids using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity assays. The IC50 values of H. sabdariffa extract were 167.14 μg/mL ± 0.843 and 77.59 μg/mL ± 0.798, respectively. In the DPPH assay, vitamin C was used as a positive control, whereas Trolox was used as a positive control in the ABTS assay. To summarise, H. sabdariffa extract contains a high concentration of total flavonoids and exhibits potent antioxidant activity. However, additional antioxidant activity assays such as superoxide dismutase (SOD), reactive oxygen species (ROS), and reactive nitrogen species (RNS) scavenging assays and in vitro antioxidant experiments should be carried out to investigate the molecular mechanism of the compound.

Keywords: ABTS assay, antioxidant activity, Gracilaria fisheri, DPPH assays, total flavonoid content

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Authors: Mehdi Ghatus

Abstract:

Two simple apparatus based on the hammer and anvil principle have been constructed and used to study the microstructure and micro-hardness characteristics of some AL-base alloys. Foils with thicknesses arranging from 20 µm up to 600 µm have been obtained. The cooling rate was estimated to be in the range 10^4 - 10^5 K/sec. Microstructure study of rapidly quenched Al-30% Si foils indicated that with decreasing the foil thickness the size of primary Si crystallites decreases in the whole investigated range (0.64-0.15 mm). However, the volume fraction of the primary Si crystals in the structure remained constant down to thickness the primary Si volume fraction started to decrease. Rapid quenching of Al- 14-16% Cu showed single phase cell structure. In foils up to 0.55 mm with decreasing the foil thickness the cell size decreases and micro-hardness increases particularly in foils below 0.3 mm in thickness. Isochronal annealing of theses foils show that the highly supersaturated Al-14-16% Cu solid solution decomposes readily at relatively low temperature and short time intervals. The maximum hardness is obtained after annealing at 100 °C for 30 minutes. However with decreasing the Cu content of the foils the precipitation process is largely delayed. Eight hours of annealing at 100 °C was not enough to achieve the maximum hardness in Al-4% Cu thin foils. The achieved hardness value was more than twice of the maximum hardness obtained in articles of similar composition but conventionally aged.

Keywords: aluminum, hardness, alloys, quenched aluminum

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Authors: Mkhokheli Sithole, Brenda N. Muchapondwa

Abstract:

Food security is becoming a critical issue for people residing mainly in the rural areas where frequent droughts interrupt food production, reduce income, compromise the ability to save and erode livelihoods. This tends to increase the vulnerability of poor households to food and income insecurity, hence, malnutrition. There is an emerging need for DRR strategies to complement the existing rain fed crop production based livelihoods. One of such strategies employed by the community of Nerumedzo in Bikita district is the harvesting of Encosternum delegorguei insect. This article analyses the livelihood impacts of Encosternum delegorguei insect as a DRR strategy. The research used a combination of qualitative and quantitative approaches. The insect samples were tested in the laboratory for their nutritional composition while surveys were done on a sample of 40 community members. Participatory observations and 5 focus group discussions were also done. The results revealed that harvesting the Encosternum delegorguei insects provides a livelihood for the locals by complementing crop production thereby mitigating potential negative effects of frequent droughts. The insects are now a significant source of income to poor households in the community.

Keywords: disaster risk reduction, livelihoods, human, social sciences

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Authors: Amina Bayazid, Habiba Fetati, Houari Toumi

Abstract:

Introduction: The clinical value of vitamin K antagonists (VKA) has been widely demonstrated in numerous indications. Unfortunately, VKA are not devoid of drawbacks and risk of serious bleeding. The iatrogenic induced by these drugs is a major public health problem. Patients & Methods: We conducted a retrospective study period extending from February 2012 to August 2013 in the pharmacovigilance service of EHUO (clinical pharmacology unit). The prescription of painkillers was analyzed in patients on VKA followed at our level. The influence of these analgesics on the evolution of the INR is an important component in our work. Results: We counted a total of 195 patients, of whom 32 (or 16.41% of the total population) had received analgesic treatment. The frequencies of different categories of analgesics administered were: • Analgesics opioids: 0% • Analgesics weak opioids: Tramadol: 21.87% • The non-opioid analgesics: -AINS: 71.87% (indomethacin: 68.75% ibuprofen: 3.12%) - Paracetamol: 6.25% -Salicyles (Acetylsalicylic acid): 0%. Conclusion: The management of pain in patients under vitamin K antagonists has special features, given their many drug interactions with analgesics and their influence on the evolution of the INR which can have dramatic consequences. As such, special attention must be paid to the use of analgesics in this type of patient.

Keywords: vitamin K antagonists, pain killers, interactions, INR

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