626 research outputs found
Study on properties of tapioca resin polymer
Environmental, global warming, renewability, recyclability, and biodegradability issues
have encouraged scientists and engineers to partially substitute petrochemical-based
polymers with green polymers such as natural fibre polymer composites. A major
drawback in the development of natural fiber polymer composites is the incompatibility
between the matrix and fibre processing temperature, given the high temperature of the
matrix based on petroleum and the low degradation temperature for natural fibre. The
creation of poly lactic acid as a “green matrix” provides an alternative and a solution for
the development of natural fiber polymer composites. In this work, the physical, thermal
and mechanical properties of PLA tapioca resin biopolymer derived from industrial
grade tapioca were reported in order to determine the optimum processing temperature.
A drying process, injection moulding and hot press process are involved in sample
preparation. A density test, hardness test, thermogravimetric analysis, and differential
scanning calorimetry have been conducted. Afterwards, a tensile test was performed
with samples at five different injection temperatures of 160°C, 165°C, 170°C, 175°C
and 180°C in order to determine the optimum processing temperature. The sample at
165°C shows the highest result of ultimate tensile strength with 14.904 MPa, and
320.564 MPa for the elastic modulus result. As a conclusion, 165°C was finalized as the
optimum processing temperature of PLA tapioca resin biopolymer for future application
in the research and development of natural fibre reinforced tapioca resin biopolymer
composite
Antimicrobial activity of bBanana (Musa paradisiaca L.) peels against food borne pathogenic microbes
Banana (Musa paradisiaca L.) peels are usually considered as wastes and are
discarded during the processing, which eventually contribute to polluting the
environment. Hence, this study was aimed to evaluate the antimicrobial activity of two
different varieties of M. paradisiaca peels, i.e., Nangka (M. paradisiaca variety Nangka)
and Tanduk (M. paradisiaca variety Tanduk) with regard to generate safe and cheap
antimicrobials as well as address pollution related issues due to such wastes.
Antimicrobial study was carried out on the extracts using disc diffusion and broth
micro-dilution methods. The best activity through disc diffusion method for bacteria
and fungi was demonstrated by Tanduk peel’s ethanol and dichloromethane extracts
against S. aureus (30 mm) and C. krusei (10 mm), respectively. However, the least active
bacteria and fungi were found to be V. parahaemolyticus and C. albicans, respectively.
The minimum inhibitory concentration (MIC) values ranged from 6.25 to 100 mg/mL.
Tanduk peel’s ethanol extract exhibited the lowest MIC and minimum bactericidal
concentration (MBC) values against B. cepacia (6.25 mg/mL) whereas for fungi, Tanduk
peel’s dichloromethane extract exhibited lowest MIC and minimum fungicidal
concentration (MFC) values against C. albicans (25 mg/mL). The results of MBC or MFC
showed that some extracts were bactericidal or fungicidal while others were bacteriostatic
or fungistatic against certain microbes. Banana peel waste’s extracts could be potential
antimicrobial alternatives and may be effective to utilize as a natural source of
antimicrobial agent in pharmaceutical industries.
Key words: Musa paradisiaca L., Nangka, Tanduk, Antimicrobial activity, MIC, MBC, MFC
Efficiency of universal barcode gene (Cox1) on morphologically cryptic Mugilidae fishes delineation.
An effort was made to assess the utility of 650 bp partial Cytochrome C oxidase subunit I (DNA barcode) gene in delineating the members of taxonomically ambiguous marine fin fishes (Family: Mugilidae). To address the issue we used all the 95 barcode sequences of Mugilidae family available at NCBI (National Centre for Biotechnological Information) along with the barcode data generated from Mugilidae fishes of Parangipettai coastal waters. The average GC content of Mugilidae was found to be 46.46%. Crenimugil crenilabis showed less GC content (44.55%) whereas Liza macrolepis showed high GC content (48.53%) among the mullet species studied. The phylogenetic and genetic distance data showed that Mugil platanus and M. liza represent the continuum of same species. Among the members of family Mugilidae, the genus Mugil might possibly contains more haplotype diversity as revealed by intra-species genetic distance data. Species within genera of Mugilidae family invariably clustered in single clade with high bootstrap value. We conclude that partial COI sequencing (barcoding) in identifying the members of the family and that way has resolved the taxonomic ambiguity among the members of the family Mugilidae
BETWEEN THE BIOACTIVE EXTRACTS OF EDIBLE MUSHROOMS AND PHARMACOLOGICALLY IMPORTANT NANOPARTICLES: NEED FOR THE INVESTIGATION OF A SYNERGISTIC COMBINATION - A MINI REVIEW
ABSTRACTThe pharmacological potential of bioactive compounds extracted from mushrooms has been studied to a reasonable level. In the same vein, thebioactivity of nanoparticles has also been investigated and reported to be of potential pharmacological benefit. No doubt, there is a reasonableamount of claims regarding the vast activity of the mushroom extracts and nanoparticles on the tested cell lines and microorganisms. In this paper,a review of the recent application of bioactive compounds extracted from two edible mushrooms (Coprinus comatus and Lactarius deliciosus), aswell as some of the recently reported studies on some nanoparticles of pharmacological potentials, was carried out. In order to check for synergy inthe bioactivity of the mushroom extracts when co-administered with nanoparticles, an investigation on the synergistic application of the materialsthrough the encapsulation of the bioactive extracts from the mushroom onto the nanoparticle was proposed. The supposed synergy in the activity ofthe extract-nanoparticle complex could hold the key to improved activity of nutraceuticals against resistant microorganisms and tumor cells.Keywords: Coprinus comatus, Lactarius deliciosus, Nanoparticles, Synergy, Bioactive extracts
α-glucosidase inhibitors isolated from Mimosa pudica L.
The aim of the study was to isolate digestive enzymes inhibitors from Mimosa pudica through a bioassay-guided fractionation approach. Repeated silica gel and sephadex LH 20 column chromatographies of bioactive fractions afforded stigmasterol, quercetin and avicularin as digestive enzymes inhibitors whose IC50 values as compared to acarbose (351.02 ± 1.46 μg mL−1) were found to be as 91.08 ± 1.54, 75.16 ± 0.92 and 481.7 ± 0.703 μg mL−1, respectively. In conclusion, M. pudica could be a good and safe source of digestive enzymes inhibitors for the management of diabetes in future
Temperature Upshift Mostly but not Always Enhances the Growth of Vibrio Species: A Systematic Review
The spread of Vibrio spp. and the prevalence of vibriosis around the world are often correlated with global warming, especially an increase in sea surface temperature. However, many ecological and virulence factors also trigger the spread of Vibrio species, while vibriosis occurs at both low and high temperatures. Recent studies that focused on a single factor (e.g. temperature) and one species (e.g. V. vulnificus) also showed that single factors such as temperature were insufficient to explain the pathogenicity and virulence of Vibrio spp. In this review, we have compiled and discussed the existing literature on the effect of temperature on different growth and pathogenicity of Vibrio spp. A systematic literature search was conducted using Web of Science (WoS) and SCOPUS databases up to 1st January 2022. After applying the selection criteria, a final list of 111 articles was included in this review. We have found that only certain Vibrio spp. are positively impacted by the increase in temperature. The results showed that 47% of the articles reported an increase in growth with the increase in temperature, while 38% showed that the relationship is complex. Reduced growth (6%) and no effect (9%) were also reported. These results showed that most but not all Vibrio spp. were positively impacted by an increase in temperature. The results indicated that V. alginolyticus, V. cholerae, V. parahaemolyticus, and V. vulnificus are the biggest threats to human and animal wellbeing
Expression of human ficolin-2 in hepatocytes confers resistance to infection by diverse hepatotropic viruses
The liver-expressed pattern recognition receptors (PRRs) mannose binding lectin (MBL), ficolin-2 and ficolin-3 contribute to the innate immune response by activating complement. Binding of soluble ficolin-2 to viral pathogens can directly neutralize virus entry. We observed that the human hepatoma cell line HuH7.5, which is routinely used for the study of hepatotropic viruses, is deficient in expression of MBL, ficolin-2 and ficolin-3. We generated a cell line that expressed and secreted ficolin-2. This cell line (HuH7.5 [FCN2]) was more resistant to infection with hepatitis C virus (HCV), ebolavirus (EBOV) and vesicular stomatitis virus (VSV), but surprisingly was more susceptible to infection with rabies virus (RABV). Cell-to-cell spread of HCV was also inhibited in ficolin-2 expressing cells. This illustrates that ficolin-2 expression in hepatocytes contributes to innate resistance to virus infection, but some viruses might utilise ficolin-2 to facilitate entry
Multiple etiologies of axonal sensory motor polyneuropathy in a renal transplant recipient: a case report
<p>Abstract</p> <p>Introduction</p> <p>Neurological complications leading to morbidity and mortality are not frequent in renal transplant recipients. Here, we report a renal transplant recipient who presented with diminished strength in his limbs probably due to multiple etiologies of axonal sensorimotor polyneuropathy, which resolved with intravenous immunoglobulin.</p> <p>Case presentation</p> <p>A 49-year-old Iranian male renal transplant recipient with previous history of autosomal dominant polycystic kidney disease presented with diminished strength in his limbs one month after surgery. Our patient was on cyclosporine A, mycophenolate mofetil and prednisone. Although a detected hypophosphatemia was corrected with supplemental phosphate, the loss of strength was still slowly progressive and diffuse muscular atrophy was remarkable in his trunk, upper limb and pelvic girdle. Meanwhile, his cranial nerves were intact. Post-transplant diabetes mellitus was diagnosed and insulin therapy was initiated. In addition, as a high serum cyclosporine level was detected, the dose of cyclosporine was reduced. Our patient was also put on intravenous ganciclovir due to positive serum cytomegalovirus immunoglobulin M antibody. Despite the reduction of oral cyclosporine dose along with medical therapy for the cytomegalovirus infection and diabetes mellitus, his muscular weakness and atrophy did not improve. One week after administration of intravenous immunoglobulin, a significant improvement was noted in his muscular weakness.</p> <p>Conclusion</p> <p>A remarkable response to intravenous immunoglobulin is compatible with an immunological basis for the present condition (post-transplant polyneuropathy). In cases of post-transplant polyneuropathy with a high clinical suspicion of immunological origin, administration of intravenous immunoglobulin may be recommended.</p
Platelets of patients with chronic kidney disease demonstrate deficient platelet reactivity in vitro
<p>Abstract</p> <p>Background</p> <p>In patients with chronic kidney disease studies focusing on platelet function and properties often are non-conclusive whereas only few studies use functional platelet tests. In this study we evaluated a recently developed functional flow cytometry based assay for the analysis of platelet function in chronic kidney disease.</p> <p>Methods</p> <p>Platelet reactivity was measured using flow cytometric analysis. Platelets in whole blood were triggered with different concentrations of agonists (TRAP, ADP, CRP). Platelet activation was quantified with staining for P-selectin, measuring the mean fluorescence intensity. Area under the curve and the concentration of half-maximal response were determined.</p> <p>Results</p> <p>We studied 23 patients with chronic kidney disease (9 patients with cardiorenal failure and 14 patients with end stage renal disease) and 19 healthy controls. Expression of P-selectin on the platelet surface measured as mean fluorescence intensity was significantly less in chronic kidney disease patients compared to controls after maximal stimulation with TRAP (9.7 (7.9-10.8) vs. 11.4 (9.2-12.2), P = 0.032), ADP (1.6 (1.2-2.1) vs. 2.6 (1.9-3.5), P = 0.002) and CRP (9.2 (8.5-10.8) vs. 11.5 (9.5-12.9), P = 0.004). Also the area under the curve was significantly different. There was no significant difference in half-maximal response between both groups.</p> <p>Conclusion</p> <p>In this study we found that patients with chronic kidney disease show reduced platelet reactivity in response of ADP, TRAP and CRP compared to controls. These results contribute to our understanding of the aberrant platelet function observed in patients with chronic kidney disease and emphasize the significance of using functional whole blood platelet activation assays.</p
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