sulfonated poly (ether ether ketone) (speek) with a low degree of sulfonation (ds = 40%) was prepared for proton exchange membrane fuel cells (pemfc). poly (ether ether ketone) (peek) was sulfonated in concentrated h2so4 under n2 atmosphere and characterized by the hydrogen nuclear magnetic resonance (h-nmr) technique. after preparation of the speek polymer, the obtained polymer was dissolved i...

background: prediction of interaction sites within the membrane protein complexes using the sequence data is of a great importance, because it would find applications in modification of molecules transport through membrane, signaling pathways and drug targets of many diseases. nevertheless, it has gained little attention from the protein structural bioinformatics community. methods: in this stu...

objective(s) extracellular matrix (ecm) and basement membrane (bm) play important roles in many developmental processes during development and after birth. among the components of the bm, collagen fibers specially type iv are the most important parts. the aim of this study was to determine the time when collagen type iv appears in the bm of lens structure during mouse embryonic development. mat...

background: with respect to physical relations in force and pressure, we hypothesized that the prevalence of traumatic tympanic membrane perforation in patients with a patulous eustachian tube is greater than normal, because in eustachian tube patency, the internal air pressure of the middle ear will not increase after compression, subsequent to trauma. therefore the force upon the tympanic mem...

bacterial utilize a multitude of methods to secretion of specific substrate across phospholipid membranes. these bacterial strategies can play many roles in promoting bacterial process, from enhancing pathogenesis to bacterial response to environmental condition. the secretion in bacterial species transfer and release performance substance such as proteins, enzymes and metabolites to environmen...

methods mycobacterium tuberculosis standard strain crbip7.11 was cultured at 37°c in loewenstein johnson (lj) media for 3-4 weeks. to confirm the species, standard microbiological and biochemical tests were performed. after preparation of membrane vesicles, the amount of protein in membrane vesicles was measured by sds-page and nanodrop. to analyze the integrity and morphology of extracellular ...

abstract basement membrane of glomerular mesangium (bmg) is a thin membrane which helps to support the capillary loops in a renal glomerulus and type iv collagen is require for complete bm formation during glomerulogenesis. in this investigation specific antibody of type iv collagen has been used in light microscopy to study development of bmg of the embryonic and postnatal mouse glomerular mes...

the kinetics of the potassium thiocyanate transport mediated by dicyclohexyl-18-crown-6 (l) through a bulk liquid membrane is studied experimentally and theoretically. the proposed model is based on the assumption of a pure diffusion of the complex salt [k·l]+scn¯ through the liquid membrane stagnant films at the interfaces. it illustrates the connection between liquid-liquid extraction equilib...

background: coverage of the bronchial stumps (bss) with adjacent tissues can improve healing and reduce bronchial complications in complex thoracic surgery. there is no evidence for the application of human amnion allograft for prevention of air leak from the bs. the comparison of the amniotic membrane (am) and pleural patch for bs healing after lobectomy in dogs was our aim in this study. mate...

conventional processes of food dewatering, such as thermal, have undesirable and destruction effects on vitamins, aromatic compounds and pigments. in addition, they are accompanied with some technological complications and energy consumption. thus, food concentration processes are directed to non-thermal techniques or methods with reduced heat effects. superabsorbents are highly hydrophilic pol...