209 research outputs found

    Anti-microbial and anti-corrosive poly (ester amide urethane) siloxane modified ZnO hybrid coatings from Thevetia peruviana seed oil

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    The utilization of renewable resources for the development of organic coatings is a viable means of creating alternatives to petroleum-based chemicals which are not eco-friendly. This paper reports the synthesis of polyesteramide– urethane–silica–zinc oxide hybrid coatings from Thevetia peruviana seed oil (TPSO). The periphery of ZnO nano-particles is modified with 3-aminopropyltrimethoxysilane to prepare silica grafted ZnO composite particles. The TPSO based polyesteramide was reacted with 4,40- diisocyanatodicyclohexylmethane in presence of siloxane modified ZnO to obtain –NCO terminated polyesteramide– urethane–silica ZnO prepolymer. These hybrid pre-polymers were casted on tin foil and cured under atmospheric moisture to obtain eco-friendly, moisture cured polyesteramide– urethanes–silica–zinc oxide hybrid coating films. The synthesized polyester and polyurethane formation was confirmed by using FT-IR and NMR spectroscopic techniques.The resultant hybrid coating films were characterized by using FT-IR, TGA, DSC, SEM, corrosion resistance and microbial resistance. Results confirm that with increase of siloxane modified ZnO content in the polyurethane matrix thermal stability, glass transition temperature and corrosion resistance improved. The antibacterial activity shows that the hybrid films exhibit excellent resistance towards Escherichia coli and Staphylococcus aureus. The salt spray test on coated panel samples show good corrosion resistance properties

    Angiopoietin-like protein 2 regulates endothelial colony forming cell vasculogenesis

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    Angiopoietin-like 2 (ANGPTL2) has been reported to induce sprouting angiogenesis; however, its role in vasculogenesis, the de novo lumenization of endothelial cells (EC), remains unexplored. We sought to investigate the potential role of ANGPTL2 in regulating human cord blood derived endothelial colony forming cell (ECFC) vasculogenesis through siRNA mediated inhibition of ANGPTL2 gene expression. We found that ECFCs in which ANGPTL2 was diminished displayed a threefold decrease in in vitro lumenal area whereas addition of exogenous ANGPTL2 protein domains to ECFCs lead to increased lumen formation within a 3 dimensional (3D) collagen assay of vasculogenesis. ECFC migration was attenuated by 36 % via ANGPTL2 knockdown (KD) although proliferation and apoptosis were not affected. We subsequently found that c-Jun NH2-terminal kinase (JNK), but not ERK1/2, phosphorylation was decreased upon ANGPTL2 KD, and expression of membrane type 1 matrix metalloproteinase (MT1-MMP), known to be regulated by JNK and a critical regulator of EC migration and 3D lumen formation, was decreased in lumenized structures in vitro derived from ANGPTL2 silenced ECFCs. Treatment of ECFCs in 3D collagen matrices with either a JNK inhibitor or exogenous rhTIMP-3 (an inhibitor of MT1-MMP activity) resulted in a similar phenotype of decreased vascular lumen formation as observed with ANGPTL2 KD, whereas stimulation of JNK activity increased vasculogenesis. Based on gene silencing, pharmacologic, cellular, and biochemical approaches, we conclude that ANGPTL2 positively regulates ECFC vascular lumen formation likely through its effects on migration and in part by activating JNK and increasing MT1-MMP expression

    Production of extracellular amylase from agricultural residues by a newly isolated Aspergillus species in solid state fermentation

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    The production of extracellular amylases by solid state fermentation (SSF) was investigated employing our laboratory isolate Aspergillus sp.MK07. Various agricultural residual substrates like wheat bran, rice bran and green gram husk were studied for enzyme production. Highest enzyme production was obtained with wheat bran as a substrate. Effects of process variables, namely: incubation period, temperature, initial moisture content, pH, supplementary carbon, nitrogen source and inoculum level on production of amylase have been studied and accordingly, optimum conditions have been determined. It was found that amylase production was highest at 120 h of incubation period at 30°C, 70% initial moisture content, 5.0 pH and 5% inoculum level. Supplementation of carbon (starch) and nitrogen source (peptone) showed an increase in amylase production and the highest amount of amylase production obtained under all optimized conditions was 164 U/g.Key words: Solid state fermentation, optimization, Aspergillus, fermentation, amylas

    The H-ARS Dose Response Relationship (DRR): Validation and Variables

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    Manipulations of lethally-irradiated animals, such as for administration of pharmaceuticals, blood sampling, or other laboratory procedures, have the potential to induce stress effects that may negatively affect morbidity and mortality. To investigate this in a murine model of the hematopoietic acute radiation syndrome, 20 individual survival efficacy studies were grouped based on the severity of the administration (Admn) schedules of their medical countermeasure (MCM) into Admn 1 (no injections), Admn 2 (1-3 injections), or Admn 3 (29 injections or 6-9 oral gavages). Radiation doses ranged from LD30/30 to LD95/30. Thirty-day survival of vehicle controls in each group was used to construct radiation dose lethality response relationship (DRR) probit plots, which were compared statistically to the original DRR from which all LDXX/30 for the studies were obtained. The slope of the Admn 3 probit was found to be significantly steeper (5.190) than that of the original DRR (2.842) or Admn 2 (2.009), which were not significantly different. The LD50/30 for Admn 3 (8.43 Gy) was less than that of the original DRR (8.53 Gy, p < 0.050), whereas the LD50/30 of other groups were similar. Kaplan-Meier survival curves showed significantly worse survival of Admn 3 mice compared to the three other groups (p = 0.007). Taken together, these results show that stressful administration schedules of MCM can negatively impact survival and that dosing regimens should be considered when constructing DRR to use in survival studies

    Constraints Perceived by Veterinarians of Tamil Nadu State of India in Providing Veterinary Services

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    Objective: To determine the constraints faced by veterinarians in rendering services to the livestock farmers. Study Design: Ex-post facto study design Methodology: Data were collected from the Veterinarians in State Department of Animal Husbandry (SDAH) of Tamil Nadu, India during the year 2019 through pre-tested semi-structured questionnaire and Garret ranking was used for analyzing the data. A total of 36 constraints were identified through focused group discussion and included in the questionnaire under different heads viz., Organizational, Job content Psychological, Institutional and Information delivery and administrative related constraints. Results: The results revealed that inadequacy of front line officers, arbitrary fixation of targets, less avenue for promotions, inadequate supporting staff and inadequate research extension linkages were identified as the major constraints that hinders the service delivery. Conclusion: this study suggested that the effectiveness of service could be further accentuated if the policy makers address the above constraints by strengthening research extension linkage, filling up of vacancies, down top approach in planning pro-poor livestock development policies with due recognition to the veterinarians.

    METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF ENTECAVIR IN BULK AND PHARMACEUTICAL DOSAGE FORMS BY RP-HPLC

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    Objective: The objective and purpose of the analysis have sensibly assessed by selecting of a rapid and sensitive RP-HPLC method for Entecavir in bulk and pharmaceutical dosage form by using the most commonly employed C-18column with UV detection.Methods: In estimation by RP-HPLC method Agilent 1120 compact LC system with variable programmable UV detector and Rheodyne injector with 20 µl fixed loop was used for the chromatographic separation. The mode of operation was isocratic with the components of a solution consisting of methanol: acetonitrile(70:30v/v) and triethanolamine (2-4drops)at the flow rate of 1.2 ml/min and run time was 10 min. Forced degradation studies were conducted to evaluate the stability and specificity of the method along with the validation parameters.Results: Validation parameters of HPLC were found at a detection wavelength of 255 nm. Linearity was observed with the concentration range (Beer's law range) 20-100µg/ml with R2=0.9991. Robustness with detection wavelengths 253 and 257 nm with a flow rate of 1 ml/min and 1.4 ml/min showed good results. The retention time of the drug was 2.64 min and assay showed 98.1%.Conclusion: The proposed RP-HPLC method was validated as per the ICH Q2B Guidelines, and was found to be applicable for routine quantitative analysis of Entecavir by RP-HPLC using UV detector in pharmaceutical dosage forms. The results of linearity, precision, accuracy and specificity, were proved, that does not exceed certain specified limits. The method provides selective quantification with no interference from other formulation excipients. The proposed method was highly sensitive, reproducible, reliable, robust and specific. Therefore, this method is a simple, rapid analysis may actually be more desirable than a more complicated and time-consuming process. The degradation studies at various stress conditions like thermal and hydrolytic, drug gets degraded at a temperature of 80 °c and refluxing with water at 70 °c for 24hours.Â

    Delayed Effects of Acute Radiation Exposure in a Murine Model of the H-ARS: Multiple-Organ Injury Consequent to <10 Gy Total Body Irradiation

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    The threat of radiation exposure from warfare or radiation accidents raises the need for appropriate animal models to study the acute and chronic effects of high dose rate radiation exposure. The goal of this study was to assess the late development of fibrosis in multiple organs (kidney, heart, and lung) in survivors of the C57BL/6 mouse model of the hematopoietic-acute radiation syndrome (H-ARS). Separate groups of mice for histological and functional studies were exposed to a single uniform total body dose between 8.53 and 8.72 Gy of gamma radiation from a Cs radiation source and studied 1-21 mo later. Blood urea nitrogen levels were elevated significantly in the irradiated mice at 9 and 21 mo (from ∼22 to 34 ± 3.8 and 69 ± 6.0 mg dL, p < 0.01 vs. non-irradiated controls) and correlated with glomerosclerosis (29 ± 1.8% vs. 64 ± 9.7% of total glomeruli, p < 0.01 vs. non-irradiated controls). Glomerular tubularization and hypertrophy and tubular atrophy were also observed at 21 mo post-total body irradiation (TBI). An increase in interstitial, perivascular, pericardial and peribronchial fibrosis/collagen deposition was observed from ∼9-21 mo post-TBI in kidney, heart, and lung of irradiated mice relative to age-matched controls. Echocardiography suggested decreased ventricular volumes with a compensatory increase in the left ventricular ejection fraction. The results indicate that significant delayed effects of acute radiation exposure occur in kidney, heart, and lung in survivors of the murine H-ARS TBI model, which mirrors pathology detected in larger species and humans at higher radiation doses focused on specific organs
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