Novel composite multilayer face masks for protection against airborne microorganisms

13-19This research focuses on the development of polyurethane (PU)/silica (SiO2) nanofibrous membranes for the filtration of PM2.5 and bacteria, which has been further incorporated in three-layered face mask comprising cotton fabric, nanofibre membrane and polyester fabric. The surface morphology, PM2.5 filtration efficiency and bacterial filtration efficiency of PU/SiO2 nanofibrous membranes have been investigated to find out applicability of nanofibrous membranes in the filtration application. PU/SiO2 nanofibrous membranes (0.5%) are found to have a pressure drop of 126 Pa with filtration efficiency of 95.37% and bacterial filtration efficiency of 99.3% against E. coli bacteria strain. Two- and three-layered fabric structures are developed comprising PU/SiO2 nanofibrous membranes and their contact angle, water vapor transmission rate and air permeability are studied to observe the breathability and waterproof behaviour of the fabric structure. Three- layered PU/SiO2 nanofibrous membranes have contact angle, water vapor transmission rate and air permeability of 145±1°, 109 g/m2/day and 8.56 cm3/s/cm2 respectively

Novel composite multilayer face masks for protection against airborne microorganisms

This research focuses on the development of polyurethane (PU)/silica (SiO2) nanofibrous membranes for the filtration of PM2.5 and bacteria, which has been further incorporated in three-layered face mask comprising cotton fabric, nanofibre membrane and polyester fabric. The surface morphology, PM2.5 filtration efficiency and bacterial filtration efficiency of PU/SiO2 nanofibrous membranes have been investigated to find out applicability of nanofibrous membranes in the filtration application. PU/SiO2 nanofibrous membranes (0.5%) are found to have a pressure drop of 126 Pa with filtration efficiency of 95.37% and bacterial filtration efficiency of 99.3% against E. coli bacteria strain. Two- and three-layered fabric structures are developed comprising PU/SiO2 nanofibrous membranes and their contact angle, water vapor transmission rate and air permeability are studied to observe the breathability and waterproof behaviour of the fabric structure. Three- layered PU/SiO2 nanofibrous membranes have contact angle, water vapor transmission rate and air permeability of 145±1°, 109 g/m2/day and 8.56 cm3/s/cm2 respectively

Significant Impact of the MTHFR Polymorphisms and Haplotypes on Male Infertility Risk

<div><p>Background</p><p>Methylenetetrahydrofolate reductase (MTHFR) converts 5,10-methylene tetrahydrofolate to 5-methyl tetrahydrofolate and affects the activity of cellular cycles participating in nucleotide synthesis, DNA repair, genome stability, maintenance of methyl pool, and gene regulation. Genetically compromised MTHFR activity has been suggested to affect male fertility. The objective of the present study was to find the impact on infertility risk of c.203G>A, c.1298A>C, and c.1793G>A polymorphisms in the MTHFR gene.</p><p>Methods</p><p>PCR-RFLP and DNA sequencing were used to genotype the common SNPs in the MTHFR gene in 630 infertile and 250 fertile males. Chi-square test was applied for statistical comparison of genotype data. Linkage disequilibrium between the SNPs and the frequency of common haplotypes were assessed using Haploview software. Biochemical levels of total homocysteine (tHcy) and folic acid were measured. Meta-analysis on c.1298A>C polymorphism was performed using data from ten studies, comprising 2734 cases and 2737 controls.</p><p>Results</p><p>c.203G>A and c.1298A>C were found to be unrelated to infertility risk. c.1793G>A was protective against infertility (P = 0.0008). c.677C>T and c.1793G>A were in significant LD (D’ = 0.9). Folic acid and tHcy level did not correlate with male infertility. Pooled estimate on c.1298A>C data from all published studies including our data showed no association of this polymorphism with male infertility (Odds ratio = 1.035, P = 0.56), azoospermia (Odds ratio = 0.97, P = 0.74), or oligoasthenoteratozoospermia (Odds ratio = 0.92, p = 0.29). Eight haplotypes with more than 1% frequency were detected, of which CCGA was protective against infertility (p = 0.02), but the significance of the latter was not seen after applying Bonferroni correction.</p><p>Conclusion</p><p>Among MTHFR polymorphisms, c.203G>A and c.1298A>C do not affect infertility risk and c.1793G>A is protective against infertility. Haplotype analysis suggested that risk factors on the MTHFR locus do not extend too long on the DNA string.</p></div

Funnel plot.

<p>Plot of precision by log odds ratio using fixed effect model for observed and imputed sets of studies.</p

Genotype and allele distribution of MTHFR SNPs in relation to sperm count.

<p>Genotype and allele distribution of MTHFR SNPs in relation to sperm count.</p

Common MTHFR haplotypes in relation to male infertility.

<p>Common MTHFR haplotypes in relation to male infertility.</p

Genotype and allele distribution of MTHFR SNPs in relation to sperm motility.

<p>Genotype and allele distribution of MTHFR SNPs in relation to sperm motility.</p

Forest plots.

<p>Meta-analysis on c.1298A>C SNP in infertility (A), oligoasthenoteratozoospermia (B), and azoospermia (C).</p

List of the SNPs analyzed along with PCR primers and techniques used for genotyping.

<p>List of the SNPs analyzed along with PCR primers and techniques used for genotyping.</p

Flow diagram showing inclusion and exclusion of the studies for meta-analysis.

<p>Studies retrieved upon literature search were subjected to inclusion/exclusion criteria as detailed in the methods section.</p