Search results for: inorganic molecular crystals

Authors: Purva Mishra, Rajesh Potlia, Kuljeet Singh Sandhu

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The role of glycyl residues in the protein structure has lingered within the research community for the last several decades. Glycyl residue is the only amino acid that is achiral due to the lack of a side chain and can, therefore, exhibit Ramachandran conformations that are disallowed for L-amino acids. The structural and functional significance of glycyl residues with L-disallowed conformation, however, remains obscure. Through statistical analysis of various datasets, we found that the glycyls with L-disallowed conformations are over-represented at disease-associated sites and tend to be evolutionarily conserved. The mutations of L-disallowed glycyls tend to destabilize the native conformation, reduce protein solubility, and promote inter-molecular aggregations. We uncovered a structural motif referred to as “β-crescent” formed around the L-disallowed glycyl, which prevents β-sheet aggregation by disrupting the alternating pattern of β-pleats. The L-disallowed conformation of glycyls also holds predictive power to infer the pathogenic missense variants. Altogether, our observations highlight that the L-disallowed conformation of glycyls is selected to facilitate native folding and prevent inter-molecular aggregations. The findings may also have implications for designing more stable proteins and prioritizing the genetic lesions implicated in diseases.

Keywords: Ramachandran plot, β-sheet, protein stability, protein aggregation

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Authors: Dalia Bednarska, Marcin Koniorczyk

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This paper presents results of experiments aimed at studying hygro-thermal properties of red clay brick. The main objective of research was to investigate the relation between thermal conductivity coefficient of brick and its water or Na2SO4 solution content. The research was conducted using stationary technique for the totally dried specimens, as well as the ones 25%, 50%, 75% and 100% imbued with water or sodium sulfate solution. Additionally, a sorption isotherm test was conducted for seven relative humidity levels. Furthermore the change of red clay brick pore structure before and after imbuing with water and salt solution was investigated by multi-cycle mercury intrusion test. The experimental results confirm negative influence of water or sodium sulphate on thermal properties of material. The value of thermal conductivity coefficient increases along with growth of water or Na₂SO₄ solution content. The study shows that the presence of Na₂SO₄ solution has less negative influence on brick’s thermal conductivity coefficient than water.

Keywords: building materials, red clay brick, sodium sulfate, thermal conductivity coefficient

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Authors: Lexuan Zhong, Chang-Seo Lee, Fariborz Haghighat, Stuart Batterman, John C. Little

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Ultraviolet photocatalytic oxidation (UV-PCO) technology has been recommended as a green approach to health indoor environment when it is integrated into mechanical ventilation systems for inorganic and organic compounds removal as well as energy saving due to less outdoor air intakes. Although much research has been devoted to UV-PCO, limited information is available on the UV-PCO behavior tested by the mixtures in literature. This project investigated UV-PCO performance and by-product generation using a single and a mixture of acetone and MEK at 100 ppb each in a single-pass duct system in an effort to obtain knowledge associated with competitive photochemical reactions involved in. The experiments were performed at 20 % RH, 22 °C, and a gas flow rate of 128 m3/h (75 cfm). Results show that acetone and MEK mutually reduced each other’s PCO removal efficiency, particularly negative removal efficiency for acetone. These findings were different from previous observation of facilitatory effects on the adsorption of acetone and MEK on photocatalyst surfaces.

Keywords: by-products, inhibitory effect, mixture, photocatalytic oxidation

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Authors: Yasser Gaber, Mohamed Ismail, Serena Bisagni, Mohamad Takwa, Rajni Hatti-Kaul

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Enzymes are safe and selective catalysts. They skillfully catalyze chemical reactions; however, the native form is not usually suitable for industrial applications. Enzymes are therefore engineered by several techniques to meet the required catalytic task. Clopidogrel is recorded among the five best selling pharmaceutical in 2010 under the brand name Plavix. The commonly used route for production of the drug on an industrial scale is the synthesis of the racemic mixture followed by diastereomeric resolution to obtain the pure S isomer. The process consumes a lot of solvents and chemicals. We have evaluated a biocatalytic cleaner approach for asymmetric hydrolysis of racemic clopidogrel. Initial screening of a selected number of hydrolases showed only one enzyme EST to exhibit activity and selectivity towards the desired stereoisomer. As the crude EST is a mixture of several isoenzymes, a homology model of EST-1 was used in molecular dynamic simulations to study the interaction of the enzyme with R and S isomers of clopidogrel. Analysis of the geometric hindrances of the tetrahedral intermediates revealed a potential site for mutagenesis in order to improve the activity and the selectivity. Single point mutation showed dramatic increase in activity and inversion of the enantioselectivity (400 fold change in E value).

Keywords: biocatalysis, biotechnology, enzyme, protein engineering, molecular modeling

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Authors: Larbi Hammadi, Abdellatif El Bari Tidjani

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In order to reduce the flow of pollutants in the wastewater of the urban agglomerations of the city of Oran, a preliminary study was carried out at the El-Karma wastewater treatment plant. The primary objective of this study was to estimate the overall physicochemical pollution in the effluents of the El-Karma sewage treatment plant wastewater. It was found that the effluent of El-Karma wastewater treatment plant contains a significant amount of insoluble. Total suspended soli TSS concentrations ranged from 112 to 475 mg/l, with an average of 220.5 mg/l. The chemical oxygen demand (COD) and biochemical oxygen demand (BOD₅) values remain within the reference range for domestic wastewater with an average value of COD < 125 and BOD₅ < 25. The COD/BOD₅ ratio of raw water entering the treatment plant is less than 2. This ratio would predict that the raw sewage from the El-Karma treatment plant is polluted by inorganic pollution strong enough.

Keywords: El-Karma wastewater, TSS concentrations, COD and BOD5, COD/BOD5 ratio, treatment

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Authors: S. M. Dankaka, N. Abdullahi

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Context: This research was conducted to isolate and identify phenol-tolerant bacteria from petroleum-contaminated sites in the northwestern part of Nigeria. Research Aim: The aim of this study was to identify bacteria with the ability to tolerate different phenol concentrations. Methodology: Samples were obtained from different petroleum-contaminated sites, and bacteria were cultured, followed by morphological, microscopic, and molecular identification. Isolates were grown on phenol-tolerant nutrient agar. The tolerant ability of the isolates was observed at 500 mg/L, 1000 mg/L, and 1500 mg/L concentrations of phenol. Findings: Two bacteria species (NWPK and NWPKD) were obtained. The total viable counts of phenol-utilizing bacteria from NWPK and NWPKD were 2.71x10⁷ and 4.0x10⁶ cfu/g, respectively. The NWPK showed its capacity to tolerate phenol at 2.3x10⁷, 2.5x10⁷, and 1.0x10⁷ cfu/g of 500, 1000, and 1500 mg/L of phenol concentration, respectively, while NWPKD tolerance ability was 1.5x10⁷, 3.8x10⁷ and 1.0x10⁷ cfu/g of 500, 1000 and 1500 mg/L of phenol respectively. The isolates were identified as Citrobacter and Acinetobacter species, respectively, based on 16S rRNA gene sequence analysis. Conclusion: The study found that these isolates showed the ability to withstand and survive high phenol concentrations in the environment.

Keywords: phenol tolerance, bacteria, petroleum contaminated sites, 16S rRNA

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Authors: B. Wang, W. H. Or, S.C. Lee, Y.C. Leung, B. Organ

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This study presents an investigation of diesel vehicle particulate-phase emissions with neat ultralow sulphur diesel (B0, ULSD) and 5% waste cooking oil-based biodiesel blend (B5) in Hong Kong. A Euro VI light duty diesel vehicle was tested under transient (New European Driving Cycle (NEDC)), steady-state and idling on a chassis dynamometer. Chemical analyses including organic carbon (OC), elemental carbon (EC), as well as 30 polycyclic aromatic hydrocarbons (PAHs) and 10 oxygenated PAHs (oxy-PAHs) were conducted. The OC fuel-based emission factors (EFs) for B0 ranged from 2.86 ± 0.33 to 7.19 ± 1.51 mg/kg, and those for B5 ranged from 4.31 ± 0.64 to 15.36 ± 3.77 mg/kg, respectively. The EFs of EC were low for both fuel blends (0.25 mg/kg or below). With B5, the EFs of total PAHs were decreased as compared to B0. Specifically, B5 reduced total PAH emissions by 50.2%, 30.7%, and 15.2% over NEDC, steady-state and idling, respectively. It was found that when B5 was used, PAHs and oxy-PAHs with lower molecular weight (2 to 3 rings) were reduced whereas PAHs/oxy-PAHs with medium or high molecular weight (4 to 7 rings) were increased. Our study suggests the necessity of taking atmospheric and health factors into account for biodiesel application as an alternative motor fuel.

Keywords: biodiesel, OC/EC, PAHs, vehicular emission

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Authors: Recep Kesli, Huseyin Bilgin, Yasar Unlu, Gokhan Gungor

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Aim: The aim of this study was to compare diagnostic values of two different molecular-based tests (GenoType® HelicoDR ve Seeplex® H. pylori-ClaR- ACE Detection) in detection presence of the H. pylori from gastric biopsy specimens. In addition to this also was aimed to determine resistance ratios of H. pylori strains against to clarytromycine and quinolone isolated from gastric biopsy material cultures by using both the genotypic (GenoType® HelicoDR, Seeplex ® H. pylori -ClaR- ACE Detection) and phenotypic (gradient strip, E-test) methods. Material and methods: A total of 266 patients who admitted to Konya Education and Research Hospital Department of Gastroenterology with dyspeptic complaints, between January 2011-June 2013, were included in the study. Microbiological and histopathological examinations of biopsy specimens taken from antrum and corpus regions were performed. The presence of H. pylori in all the biopsy samples was investigated by five differnt dignostic methods together: culture (C) (Portagerm pylori-PORT PYL, Pylori agar-PYL, GENbox microaer, bioMerieux, France), histology (H) (Giemsa, Hematoxylin and Eosin staining), rapid urease test (RUT) (CLOtest, Cimberly-Clark, USA), and two different molecular tests; GenoType® HelicoDR, Hain, Germany, based on DNA strip assay, and Seeplex ® H. pylori -ClaR- ACE Detection, Seegene, South Korea, based on multiplex PCR. Antimicrobial resistance of H. pylori isolates against clarithromycin and levofloxacin was determined by GenoType® HelicoDR, Seeplex ® H. pylori -ClaR- ACE Detection, and gradient strip (E-test, bioMerieux, France) methods. Culture positivity alone or positivities of both histology and RUT together was accepted as the gold standard for H. pylori positivity. Sensitivity and specificity rates of two molecular methods used in the study were calculated by taking the two gold standards previously mentioned. Results: A total of 266 patients between 16-83 years old who 144 (54.1 %) were female, 122 (45.9 %) were male were included in the study. 144 patients were found as culture positive, and 157 were H and RUT were positive together. 179 patients were found as positive with GenoType® HelicoDR and Seeplex ® H. pylori -ClaR- ACE Detection together. Sensitivity and specificity rates of studied five different methods were found as follows: C were 80.9 % and 84.4 %, H + RUT were 88.2 % and 75.4 %, GenoType® HelicoDR were 100 % and 71.3 %, and Seeplex ® H. pylori -ClaR- ACE Detection were, 100 % and 71.3 %. A strong correlation was found between C and H+RUT, C and GenoType® HelicoDR, and C and Seeplex ® H. pylori -ClaR- ACE Detection (r:0.644 and p:0.000, r:0.757 and p:0.000, r:0.757 and p:0.000, respectively). Of all the isolated 144 H. pylori strains 24 (16.6 %) were detected as resistant to claritromycine, and 18 (12.5 %) were levofloxacin. Genotypic claritromycine resistance was detected only in 15 cases with GenoType® HelicoDR, and 6 cases with Seeplex ® H. pylori -ClaR- ACE Detection. Conclusion: In our study, it was concluded that; GenoType® HelicoDR and Seeplex ® H. pylori -ClaR- ACE Detection was found as the most sensitive diagnostic methods when comparing all the investigated other ones (C, H, and RUT).

Keywords: Helicobacter pylori, GenoType® HelicoDR, Seeplex ® H. pylori -ClaR- ACE Detection, antimicrobial resistance

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Authors: Nutnicha Wongpadungkiat, Suwit Siriwatanayotin, Aluck Thipayarat, Punchira Vongsawasdi, Chotika Viriyarattanasak

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Chicken products are major export product of Thailand. With a dramatically increasing consumption of chicken product in the world, there are abundant wastes from chicken meat processing industry. Recently, much research in the development of value-added products from chicken meat industry has focused on the production of protein hydrolysate, utilized as food ingredients for human diet and animal feed. The present study aimed to determine the effect of thermal pre-treatment on functional properties of chicken protein hydrolysate. Chicken breasts were heated at 40, 60, 80 and 100ºC prior to hydrolysis by Alcalase at 60ºC, pH 8 for 4 hr. The hydrolysate was freeze-dried, and subsequently used for assessment of its functional properties molecular weight by gel electrophoresis (SDS-PAGE). The obtained results show that increasing the pre-treatment temperature increased oil holding capacity and emulsion stability while decreasing antioxidant activity and water holding capacity. The SDS-PAGE analysis showed the evidence of protein aggregation in the hydrolysate treated at the higher pre-treatment temperature. These results suggest the connection between molecular weight of the hydrolysate and its functional properties.

Keywords: chicken protein hydrolysate, enzymatic hydrolysis, thermal pretreatment, functional properties

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Authors: Nadia Naseem, Farwa Batool, Nasir Mehmood, AbdulHannan Nagi

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Background: The incidence and mortality of breast cancer vary significantly in geographically distinct populations. In Pakistan, breast cancer has shown an increase in incidence in young females and is characterized by more aggressive behavior. The tumor suppressor TP53 gene is a crucial genetic factor that plays a significant role in breast carcinogenesis. This study investigated the TP53 mutations in molecular subtypes of both nodes negative and positive breast cancer in young Pakistani patients. Material and Methods: p53, Estrogen Receptor (ER), Progesterone Receptor (PR), Her-2 neu and Ki 67 expressions were analyzed immunohistochemically in a series of 75 node negative (A) and 75 node positive (B) young (aged: 19-40 years) breast cancer patients diagnosed between 2014 to 2017 at two leading hospitals of Punjab, Pakistan. Tumor tissue specimens and peripheral blood samples were examined for TP53 mutations by direct sequencing of the gene (exons 4-9). The relation of TP53 mutations to these markers and clinicopathological data was investigated. Results: Mean age of the patients was 32.4 + 9.1 SD. Invasive breast carcinoma was the most frequent histological variant (A=92%, B=94.6%). Grade 3 carcinoma was the commonest grade (A=72%, B=81.3%). Triple negative cases (ER-, PR-, Her-2) formed most of the molecular subtypes (A=44%, B=50.6%). A total of 17.2% (A: 6.6%, B: 10.6%) patients showed TP53 mutations. Mutations were significantly more frequent in triple negative cases (A: 74.8%, B: 62.2%) compared to HER2-positive patients (P < 0.0001). In the multivariate analysis of the whole patient group, the independent prognosticator were triple negative cases (P=0.021), TP53 overexpression by IHC (P=0.001) and advanced-stage disease (P=0.007). No statistically significant correlation between TP53 mutations and clinicopathological parameters was found (P < 0.05). Conclusions: It is concluded that TP53 mutations are infrequently present in breast carcinoma of young Pakistani population and there was no significant correlation between p53 mutation and early onset disease. Immunohistochemically detected TP53 expression in our resource-constrained to set up can be beneficial in predicting mutations at the younger age in our population.

Keywords: immunohistochemistry (IHC), invasive breast carcinoma (IBC), Pakistan, TP53

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Authors: Mina Kalantarzadeh, Claire Lockie-Williams, Caroline Howard

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DNA barcoding is increasingly used for identification of medicinal plants worldwide. In the last decade, a large number of DNA barcodes have been generated, and their application in species identification explored. The success of DNA barcoding process relies on the accuracy of the results from polymerase chain reaction (PCR) amplification step which could be negatively affected due to a presence of inhibitors or degraded DNA in herbal samples. An established DNA reference material can be used to support molecular characterisation protocols and prove system suitability, for fast and accurate identification of plant species. The present study describes the use of a novel reference material, the trnH-psbA British Pharmacopoeia Nucleic Acid Reference Material (trnH-psbA BPNARM), which was produced to aid in the identification of Ocimum tenuiflorum L., a widely used herb. During DNA barcoding of O. tenuiflorum, PCR amplifications of isolated DNA produced inconsistent results, suggesting an issue with either the method or DNA quality of the tested samples. The trnH-psbA BPNARM was produced and tested to check for the issues caused during PCR amplification. It was added to the plant material as control DNA before extraction and was co-extracted and amplified by PCR. PCR analyses revealed that the amplification was not as successful as expected which suggested that the amplification is affected by presence of inhibitors co-extracted from plant materials. Various potential issues were assessed during DNA extraction and optimisations were made accordingly. A DNA barcoding protocol for O. tenuiflorum was published in the British Pharmacopoeia 2016, which included the reference sequence. The trnH-psbA BPNARM accelerated degradation test which investigates the stability of the reference material over time demonstrated that it has been stable when stored at 56 °C for a year. Using this protocol and trnH-psbA reference material provides a fast and accurate method for identification of O. tenuiflorum. The optimisations of the DNA extraction using the trnH-psbA BPNARM provided a signposting method which can assist in overcoming common problems encountered when using molecular methods with medicinal plants.

Keywords: degradation, DNA extraction, nucleic acid reference material, trnH-psbA

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Authors: Marianna Maiaru, Gregory M. Odegard, Josh Kemppainen, Ivan Gallegos, Michael Olaya

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Ceramic matrix composites (CMCs) are typically used in applications that require long-term mechanical integrity at elevated temperatures. CMCs are usually fabricated using a polymer precursor that is initially polymerized in situ with fiber reinforcement, followed by a series of cycles of pyrolysis to transform the polymer matrix into a rigid glass or ceramic. The pyrolysis step typically generates volatile gasses, which creates porosity within the polymer matrix phase of the composite. Subsequent cycles of monomer infusion, polymerization, and pyrolysis are often used to reduce the porosity and thus increase the durability of the composite. Because of the significant expense of such iterative processing cycles, new generations of CMCs with improved durability and manufacturability are difficult and expensive to develop using standard Edisonian approaches. The goal of this research is to develop a computational process-modeling-based approach that can be used to design the next generation of CMC materials with optimized material and processing parameters for maximum strength and efficient manufacturing. The process modeling incorporates computational modeling tools, including molecular dynamics (MD), to simulate the material at multiple length scales. Results from MD simulation are used to inform the continuum-level models to link molecular-level characteristics (material structure, temperature) to bulk-level performance (strength, residual stresses). Processing parameters are optimized such that process-induced residual stresses are minimized and laminate strength is maximized. The multiscale process modeling method developed with this research can play a key role in the development of future CMCs for high-temperature and high-strength applications. By combining multiscale computational tools and process modeling, new manufacturing parameters can be established for optimal fabrication and performance of CMCs for a wide range of applications.

Keywords: digital engineering, finite elements, manufacturing, molecular dynamics

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Authors: F. Garousi, Sz. Veres, É. Bódi, Sz. Várallyay, B. Kovács

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Specific leaf area (SLA; cm2leaf g-1leaf) is a key ecophysiological parameter influencing leaf physiology, photosynthesis, and whole plant carbon gain and also can be used as a rapid and diagnostic tool. In this study, two species of soluble inorganic selenium forms, selenite (SeIV) and selenate (SeVI) at different concentrations were investigated on maize plants that were growing in nutrient solutions during 2 weeks and at the end of the experiment, amounts of SLA for first and second leaves of maize were measured. In accordance with the results we observed that our regarded Se concentrations in both forms of SeIV and SeVI were not effective on maize plants’ SLA significantly although high level of 3 mg.kg-1 SeIV had negative affect on growth of the samples that had been treated by it but about SeVI samples we did not observe this state and our different considered SeVI concentrations were not toxic for maize plants.

Keywords: maize, sodium selenate, sodium selenite, specific leaf area

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Authors: Vrushali Guhe, Shailza Singh

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Cutaneous leishmaniasis is neglected tropical disease present worldwide caused by the protozoan parasite Leishmania major, the therapeutic armamentarium for leishmaniasis are showing several limitations as drugs are showing toxic effects with increasing resistance by a parasite. Thus identification of novel therapeutic targets is of paramount importance. Previous studies have shown that autophagy, a cellular process, can either facilitate infection or aid in the elimination of the parasite, depending on the specific parasite species and host background in leishmaniasis. In the present study, our objective was to target the essential autophagy protein ATG8, which plays a crucial role in the survival, infection dynamics, and differentiation of the Leishmania parasite. ATG8 in Leishmania major and its homologue, LC3, in Homo sapiens, act as autophagic markers. Present study manifested the crucial role of ATG8 protein as a potential target for combating Leishmania major infection. Through bioinformatics analysis, we identified non-conserved motifs within the ATG8 protein of Leishmania major, which are not present in LC3 of Homo sapiens. Against these two non-conserved motifs, we generated a peptide library of 60 peptides on the basis of physicochemical properties. These peptides underwent a filtering process based on various parameters, including feasibility of synthesis and purification, compatibility with Selective Reaction Monitoring (SRM)/Multiple reaction monitoring (MRM), hydrophobicity, hydropathy index, average molecular weight (Mw average), monoisotopic molecular weight (Mw monoisotopic), theoretical isoelectric point (pI), and half-life. Further filtering criterion shortlisted three peptides by using molecular docking and molecular dynamics simulations. The direct interaction between ATG8 and the shortlisted peptides was confirmed through Surface Plasmon Resonance (SPR) experiments. Notably, these peptides exhibited the remarkable ability to penetrate the parasite membrane and exert profound effects on Leishmania major. The treatment with these peptides significantly impacted parasite survival, leading to alterations in the cell cycle and morphology. Furthermore, the peptides were found to modulate autophagosome formation, particularly under starved conditions, suggesting their involvement in disrupting the regulation of autophagy within Leishmania major. In vitro, studies demonstrated that the selected peptides effectively reduced the parasite load within infected host cells. Encouragingly, these findings were corroborated by in vivo experiments, which showed a reduction in parasite burden upon peptide administration. Additionally, the peptides were observed to affect the levels of LC3II within host cells. In conclusion, our findings highlight the efficacy of these novel peptides in targeting Leishmania major’s ATG8 and disrupting parasite survival. These results provide valuable insights into the development of innovative therapeutic strategies against leishmaniasis via targeting autophagy protein ATG8 of Leishmania major.

Keywords: ATG8, leishmaniasis, surface plasmon resonance, MD simulation, molecular docking, peptide designing, therapeutics

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Authors: Bilal Ahmad

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Alzheimer’s disease (AD) is one of the most common neurodegenerative illnesses. However, how Gut-microbiota plays a role in the pathogenesis of AD is not well elucidated. The purpose of this literature review is to summarize and understand the current findings that may elucidate the gut microbiota's role in the development of AD. Methods: A literature review of all the relevant papers known to the author was conducted. Relevant articles, abstracts and research papers were collected from well-accepted web sources like PubMed, PMC, and Google Scholar. Results: Recent studies have shown that Gut-microbiota has an important role in the progression of AD via Gut-Microbiota-Brain Axis. The onset of AD supports the ‘Hygiene Hypothesis’, which shows that AD might begin in the Gut, causing dysbiosis, which interferes with the intestinal barrier by releasing pro-inflammatory cytokines and making its way up to the brain via the blood-brain barrier (BBB). Molecular mechanisms lipopolysaccharides and serotonin kynurenine (tryptophan) pathways have a direct association with inflammation, the immune system, neurodegeneration, and AD. Conclusion: The studies helped to analyze the molecular basis of AD, other neurological conditions like depression, autism, and Parkinson's disease and how they are linked to Gut-microbiota. Further, studies to explore the therapeutic effects of probiotics in AD and cognitive enhancement should be warranted to provide significant clinical and practical value.

Keywords: gut-microbiota, Alzheimer’s disease, second brain aging, lipopolysaccharides, short-chain fatty acids

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Authors: Senda Trabelsi, Sébastien Poncet, Michel Poirier

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Ice slurries are considered as a promising phase-changing secondary fluids for air-conditioning, packaging or cooling industrial processes. An experimental study has been here carried out to measure the rheological characteristics of ice slurries. Ice slurries consist in a solid phase (flake ice crystals) and a liquid phase. The later is composed of a mixture of liquid water and an additive being here either (1) Propylene-Glycol (PG) or (2) Ethylene-Glycol (EG) used to lower the freezing point of water. Concentrations of 5%, 14% and 24% of both additives are investigated with ice mass fractions ranging from 5% to 85%. The rheological measurements are carried out using a Discovery HR-2 vane-concentric cylinder with four full-length blades. The experimental results show that the behavior of ice slurries is generally non-Newtonian with shear-thinning or shear-thickening behaviors depending on the experimental conditions. In order to determine the consistency and the flow index, the Herschel-Bulkley model is used to describe the behavior of ice slurries. The present results are finally validated against an experimental database found in the literature and the predictions of an Artificial Neural Network model.

Keywords: ice slurry, propylene-glycol, ethylene-glycol, rheology

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Authors: Sérgio Afonso Mulema, Andrés Carrión García, Vicente Ernesto

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This paper analyses the effect of fertilizer (organic and inorganic) in the growth of tilapia. An experiment was implemented in the Aquapesca Company of Mozambique; there were considered four different treatments. Each type of fertilizer was applied in two of these treatments; a feed was supplied to the third treatment, and the fourth was taken as control. The weight and length of the tilapia were used as the growth parameters, and to measure the water quality, the physical-chemical parameters were registered. The results show that the weight and length were different for tilapias cultivated in different treatments. These differences were evidenced mainly by organic and feed treatments, where there was the largest and smallest value of these parameters, respectively. In order to prove that these differences were caused only by applied treatment without interference for the aquatic environment, a Fisher discriminant analysis was applied, which confirmed that the treatments were exposed to the same environment condition.

Keywords: fertilizer, tilapia, growth, statistical methods

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Authors: Tatiana A. Dolenko, Sergey A. Burikov, Alexander O. Efitorov, Sergey A. Dolenko

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In this study, a comparative analysis of the approaches associated with the use of neural network algorithms for effective solution of a complex inverse problem – the problem of identifying and determining the individual concentrations of inorganic salts in multicomponent aqueous solutions by the spectra of Raman scattering of light – is performed. It is shown that application of artificial neural networks provides the average accuracy of determination of concentration of each salt no worse than 0.025 M. The results of comparative analysis of input data compression methods are presented. It is demonstrated that use of uniform aggregation of input features allows decreasing the error of determination of individual concentrations of components by 16-18% on the average.

Keywords: inverse problems, multi-component solutions, neural networks, Raman spectroscopy

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Authors: Harminder Kaur, Manpreet Kaur, Akanksha Kapila, Reenu

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Schiff base with general formula H₂L was derived from condensation of o-vanillin and 3-nitro-o-phenylenediamine. This Schiff base was used for the synthesis of organotin(IV) complexes with general formula R₂SnL [R=Phenyl or n-octyl] using equimolar quantities. Elemental analysis UV-Vis, FTIR, and multinuclear spectroscopic techniques (¹H, ¹³C, and ¹¹⁹Sn) NMR were carried out for the characterization of the synthesized complexes. These complexes were coloured and soluble in polar solvents. Computational studies have been performed to obtain the details of the geometry and electronic structures of ligand as well as complexes. Geometry of the ligands and complexes have been optimized at the level of Density Functional Theory with B3LYP/6-311G (d,p) and B3LYP/MPW1PW91 respectively followed by vibrational frequency analysis using Gaussian 09. Observed ¹¹⁹Sn NMR chemical shifts of one of the synthesized complexes showed tetrahedral geometry around Tin atom which is also confirmed by DFT. HOMO-LUMO energy distribution was calculated. FTIR, ¹HNMR and ¹³CNMR spectra were also obtained theoretically using DFT. Further IRC calculations were employed to determine the transition state for the reaction and to get the theoretical information about the reaction pathway. Moreover, molecular docking studies can be explored to ensure the anticancer activity of the newly synthesized organotin(IV) complexes.

Keywords: DFT, molecular docking, organotin(IV) complexes, o-vanillin, 3-nitro-o-phenylenediamine

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Authors: R. F. B. Gonçalves, E. N. Iwama, J. A. F. F. Rocco, K. Iha

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Propellants based on Hydroxyl Terminated Polybutadiene/Ammonium Perchlorate (HTPB/AP) are the most commonly used in most of the rocket engines used by the Brazilian Armed Forces. This work aimed at the possibility of extending its useful life (currently in 10 years) by performing kinetic-chemical analyzes of its energetic material via Differential Scanning Calorimetry (DSC) and also performing computer simulation of aging process using the software Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). Thermal analysis via DSC was performed in triplicates and in three heating ratios (5 ºC, 10 ºC, and 15 ºC) of rocket motor with 11 years shelf-life, using the Arrhenius equation to obtain its activation energy, using Ozawa and Kissinger kinetic methods, allowing comparison with manufacturing period data (standard motor). In addition, the kinetic parameters of internal pressure of the combustion chamber in 08 rocket engines with 11 years of shelf-life were also acquired, for comparison purposes with the engine start-up data.

Keywords: shelf-life, thermal analysis, Ozawa method, Kissinger method, LAMMPS software, thrust

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Authors: Shreya Sara Ittycheria, K. C. Sivakumar, Shijulal Nelson Sathi, Priya Srinivas

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hCG, a heterodimer composed of α and β subunits, is a peptide hormone having numerous biological functions. Although hCG is expressed by placenta during pregnancy, ectopic β-hCG secretion is observed in many non-trophoblastic tumors including that of breast. In-vitro and in-vivo studies done in the lab, have proved that BRCA1 defective cancers express β-hCG and when β-hCG is expressed or supplemented, it promotes tumor progression and exhibits resistance to carboplatin and ABT888, in such cancers but not in BRCA1 wild type cancers. In cancer cells, instead of binding to its regular receptor, LH-CGR, β-hCG binds with Transforming Growth Factor Receptor 2 (TGFβRII) and phosphorylates it resulting in faster tumor progression through the Smad signaling pathway. Targeting β-hCG could be a potential therapeutic strategy for managing BRCA1 defective cancers. Here, molecular docking and dynamic simulation studies were done to identify potential small molecule inhibitors against β-hCG as there are currently no such inhibitors reported. The binding sites of TGFβRII on β-hCG were identified from the top 10 predicted complexes from Z Dock. Virtual screening of selected commercially available small molecules from various libraries such as ZINC, NCI and Life Chemicals amounting to a total of 50,025 molecules were done. Four potential small molecule inhibitors were identified, RgcbPs-1, RgcbPs-2, RgcbPs-3 and RgcbPs-4 with binding affinities -60.778 kcal/mol, -45.447 kcal/mol, -65.2268 kcal/mol and -82.040 kcal/mol respectively. Further, 100ns Molecular Dynamics (MD) simulation showed that these molecules form stable complexes with β-hCG. RgcbPs-1 maintains hydrogen bonds with Q54, L52, Q46, C100, G36, C57, C38 residues, RgcbPs-2 maintains hydrogen bonds with A83 residue, RgcbPs-3 maintains hydrogen bonds with C57, Y58, R94, G101 residues and RgcbPs-4 maintains hydrogen bonds with G36, C38, T40, C57, D99, C100, G101 and L104 residues of β-hCG all of which coincide with the TGFβRII binding site on β-hCG. These results show that these two inhibitors could be used either singly or in combination for inhibiting β-hCG from binding to TGFβRII and thereby directly inhibiting the tumorigenesis pathway.

Keywords: β-hCG, breast cancer, dynamic simulations, molecular docking, small molecule inhibitors, virtual screening.

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Authors: Barsha Saha, Shouvik Chakravarty, Sukanta Ray, Kshaunish Das, Nidhan K. Biswas, Srikanta Goswami

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Pancreatic Ductal Adenocarcinoma is a well-recognised cause of cancer death with a five-year survival rate of about 9%, and its incidence in India has been found to be increased manifold in recent years. Due to delayed detection, this highly metastatic disease has a poor prognosis. Several molecular alterations happen during the progression of the disease from pre-cancerous conditions, and many such alterations could be investigated for their biomarker potential. MicroRNAs have been shown to be prognostic for PDAC patients in a variety of studies. We hereby used NGS technologies to evaluate the role of small RNA changes during pancreatic cancer development from chronic pancreatitis. Plasma samples were collected from pancreatic cancer patients (n=16), chronic pancreatitis patients (n=8), and also from normal individuals (n=16). Pancreatic tumour tissue (n=5) and adjacent normal tissue samples (n=5) were also collected. Sequencing of small RNAs was carried out after small RNAs were isolated from plasma samples and tissue samples. We find that certain microRNAs are highly deregulated in pancreatic cancer patients in comparison to normal samples. A combinatorial analysis of plasma and tissue microRNAs and subsequent exploration of their targets and altered molecular pathways could not only identify potential biomarkers for disease diagnosis but also help to understand the underlying mechanism.

Keywords: small RNA sequencing, pancreatic cancer, biomarkers, tissue sample

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Authors: J. Suwanprateeb, F. Thammarakcharoen

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Calcium phosphate coating (CaP) has been employed for protein delivery, but the typical direct protein adsorption on the coating led to low incorporation content and fast release of the protein from the coating. By using bovine serum albumin (BSA) as a model protein, rapid biomimetic co-precipitation between calcium phosphate and BSA was employed to control the distribution of BSA within calcium phosphate coating during biomimetic formation on titanium surface for only 6 h at 50 oC in an accelerated calcium phosphate solution. As a result, the amount of BSA incorporation and release duration could be increased by using a rapid biomimetic co-precipitation technique. Up to 43 fold increases in the BSA incorporation content and the increase from 6 h to more than 360 h in release duration compared to typical direct adsorption technique were observed depending on the initial BSA concentration used during co-precipitation (1, 10, and 100 microgram/ml). From X-ray diffraction and Fourier transform infrared spectroscopy studies, the coating composition was not altered with the incorporation of BSA by this rapid biomimetic co-precipitation and mainly comprised octacalcium phosphate and hydroxyapatite. However, the microstructure of calcium phosphate crystals changed from straight, plate-like units to curved, plate-like units with increasing BSA content.

Keywords: biomimetic, Calcium Phosphate Coating, protein, titanium

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Authors: Young-Cheol Choi, Joo-Hyung Kim, Gyu-Don Moon

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This paper discusses the effect of Na2O (alkali) content, SiO2/Na2O mole ratio, and elevated temperature on the mechanical performance of fly-ash-based inorganic green geopolymer composites. Fly-ash-based geopolymers, which were manufactured with varying alkali contents (4–8 % of fly ash weight) and SiO2/Na2O mole ratios (0.6–1.4), were subjected to elevated temperatures up to 900 ºC ; the geopolymer composites and their performance were evaluated on the basis of weight loss and strength loss after temperature exposure. In addition, mineralogical changes due to the elevated temperature exposure were studied using x-ray diffraction. Investigations of microstructures and microprobe analysis were performed using mercury intrusion porosimetry. The results showed that the fly-ash-based geopolymer responded significantly to high-temperature conditions.

Keywords: fly ash, geopolymer, micro-structure, high-temperature, mechanical structural

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Authors: Jessica C. Bannon, Cleso M. Jordao Jr., Mohammad Melebari, Carlos Leon-Velarde, Roger Johnson, Keith Warriner

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There has been an increased incidence of non-O157 Shiga Toxin Escherichia coli (STEC) with six serotypes (Top 6) being implicated in causing haemolytic uremic syndrome (HUS). Beef has been suggested to be a significant vehicle for non-O157 STEC although conclusive evidence has yet to be obtained. The following aimed to determine the prevalence of the Top 6 non-O157 STEC in beef processing using three different diagnostic platforms then characterize the recovered isolates. Hide, carcass and environmental swab samples (n = 60) were collected from a beef processing facility over a 12 month period. Enriched samples were screened using Biocontrol GDS, BAX or PALLgene molecular diagnostic tests. Presumptive non-O157 STEC positive samples were confirmed using conventional PCR and serology. STEC was detected by GDS (55% positive), BAX (85% positive), and PALLgene (93%). However, during confirmation testing only 8 of the 60 samples (13%) were found to harbour STEC. Interestingly, the presence of virulence factors in the recovered isolates was unstable and readily lost during subsequent sub-culturing. There is a low prevalence of Top 6 non-O157 STEC associated with beef although other serotypes are encountered. Yet, the instability of the virulence factors in recovered strains would question their clinical relevance.

Keywords: beef, food microbiology, shiga toxin, STEC

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Authors: Maria Bercea, Bernhard A. Wolf

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The thermodynamic behavior for solutions of poly (methyl methacrylate-ran-t-butyl methacrylate) of variable composition as compared with the corresponding homopolymers was investigated by light scattering measurements carried out for dilute solutions and vapor pressure measurements of concentrated solutions. The complex dependencies of the Flory Huggins interaction parameter on concentration and copolymer composition in solvents of different polarity (toluene and chloroform) can be understood by taking into account the ability of the polymers to rearrange in a response to changes in their molecular surrounding. A recent unified thermodynamic approach was used for modeling the experimental data, being able to describe the behavior of the different solutions by means of two adjustable parameters, one representing the effective number of solvent segments and another one accounting for the interactions between the components. Thus, it was investigated how the solvent quality changes with the composition of the copolymers through the Gibbs energy of mixing as a function of polymer concentration. The largest reduction of the Gibbs energy at a given composition of the system was observed for the best solvent. The present investigation proves that the new unified thermodynamic approach is a general concept applicable to homo- and copolymers, independent of the chain conformation or shape, molecular and chemical architecture of the components and of other dissimilarities, such as electrical charges.

Keywords: random copolymers, Flory Huggins interaction parameter, Gibbs energy of mixing, chemical architecture

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Authors: Mansi Srivastava, Uzma Saqib, Adnan Naim, Anjali Roy, Dongfang Liu, Deepak Bhatnagar, Ravinder Ravinder, Mirza S. Baig

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Macrophages polarize to proinflammatory M1 or anti-inflammatory M2 states with distinct physiological functions. This transition within the M1 to M2 phenotypes decides the nature, duration, and severity of an inflammatory response. However, inspite of a substantial understanding of the fate of these phenotypes, the underlying molecular mechanisms are not well understood. We have investigated the role of Neuronal nitric oxide synthase (NOS1) mediated regulation of Activator protein 1 (AP-1) transcription factor in macrophages as a critical effector of macrophage phenotypic change. Activator protein 1 (AP-1) is a group of dimeric transcription factors composed of jun, Fos, and ATF family proteins. We determined that NOS1-derived nitric oxide (NO) facilitate Fos and jun interaction which induces IL12 & IL23 expression. Pharmacological inhibition of NOS1 inhibits Fos and jun interaction but increases ATF2 and Fos dimerization. Switching of Fos and jun dimer to ATF2 and jun dimerization switches phenotype from IL–12high IL-23high IL-10low to IL–12low IL-23lowIL-10high phenotype, respectively. Together, these findings highlight a key role of the TLR4-NOS1-AP1 signaling axis in regulating macrophage polarization.

Keywords: inflammation, macrophage, lipopolysaccharide (LPS), proinflammatory cytokines, activator protein 1 (AP-1), neuronal nitric oxide synthase (NOS1)

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Authors: Andrea Szabo Nagy, Zsofia Csanadi

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The purpose of this study was to evaluate the concentration levels of common inorganic gases, benzene and particulate matter (PM₁₀ and PM₂.₅) in ambient air of Győr (Hungary) based on the latest published monitoring data. The concentrations of PM10-bound heavy metals (Pb, Cd, As and Ni) and some polycyclic aromatic hydrocarbons (PAHs) were also assessed. The levels of pollutants were compared with the Hungarian and EU limit or target values defined for health protection and the WHO air quality guidelines (AQGs) or estimated reference levels. Based on the Hungarian or the EU air quality standards and using the Hungarian Air Quality Index it was found that mainly an excellent (SO₂, CO, C₆H₆, heavy metals) or good (NO₂, O₃, PM₁₀, PM₂.₅, benzo(a)pyrene (BaP)) air quality was observed in the urban area of Győr for the year 2016. The annual mean pollutant concentrations (excluding BaP) were not exceeded or just reached the WHO AQGs or reference levels.

Keywords: aerosols, air pollutant, air quality, health protection

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Authors: Mokhtar Nikgoo

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Definition of Concrete and Concreting: Concrete (in French: Béton) in a broad sense is any substance or combination that consists of a sticky substance with the property of cementation. In general, concrete refers to concrete made by Portland cement, which is produced by mixing fine and coarse aggregates, Portland cement and water. After enough time, this mixture turns into a stone-like substance. During the hardening or processing of the concrete, cement is chemically combined with water to form strong crystals that bind the aggregates together, a process called hydration. During this process, significant heat is released called hydration heat. Additionally, concrete shrinks slightly, especially as excess water evaporates, a phenomenon known as drying shrinkage. The process of hardening and the gradual increase in concrete strength that occurs with it does not end suddenly unless it is artificially interrupted. Instead, it decreases more over long periods of time, although, in practical applications, concrete is usually set after 28 days and is considered at full design strength. Concrete may be made from different types of cement as well as pozzolans, furnace slag, additives, additives, polymers, fibers, etc. It may also be used in the way it is made, heating, water vapor, autoclave, vacuum, hydraulic pressures and various condensers.

Keywords: concrete, RCC, batching, cement, Pozzolan, mixing plan

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Authors: Jonmichael Weaver, David Miller

Abstract:

Dyneema is an ultra-high molecular weight polyethylene (UHMWPE) fiber created by DSM. This fiber has many applications due to the high tensile strength, low weight, and inability to absorb water. DSM manufactures a non-woven unidirectional cross-ply [0,90]2 lamina, using the Dyneema fiber. Using this lamina system, various thickness panels are created for a 40% lighter weight alternative to Kevlar for the same ballistics protection. Environmental effects on the ply/laminate system alter the material properties, resulting in diminished ultimate performance. Understanding the specific environmental parameters and characterizing the resulting material property degradation is essential for determining the safety and reliability of Dyneema in service. Two laminas were contrasted for their response to accelerated aging by UV, humidity, and temperature cycling. Both lamina contain the same fiber, SK-99, but differ in matrix composition, Dyneema HB-210 employs a polyurethane (PUR) based matrix, and HB-212 contains a rubber-based matrix. Each system was inspected using a scanning electron microscope (SEM) and evaluated by dynamic mechanical analysis (DMA) to characterize the material property changes alongside the corresponding composite damage and matrix failure mode over the aging parameters. Overall, resulting in the HB-212 degrading faster compared with the HB-210.

Keywords: dyneema, accelerated aging, polymers, ballistics protection, armor, DSM, kevlar, composites

Procedia PDF Downloads 149