149 research outputs found

    Configurational entropy calculation of poly(α-alkyl β,L-aspartate)s amorphous and crystalline films using gas permeation

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    The permeability and diffusion coefficient of gases such as N-2, O-2 and CO2 through two polymeric membranes of poly(alpha-alkyl beta,L-aspartate)s (PAALA-n) were determined by the "time-lag" method. One of these membranes was crystalline (PAALA-1) and the other one was amorphous (PAALA-6). The comparison of the obtained result for both membranes is addressed by the calculation of the so called configurational entropy. The study has been done in the range of temperatures 20 degrees C to 70 degrees C.This work was supported by the Direccion General de Investigacion Cientifica y Tecnica (DGICYT), Grant ENE-2011-Ref.24761 and also DGAPA-UNAM Proyecto IN 102512, and SEP-CONACYT 154626.Del Castillo, LF.; Andrio Balado, A.; Nava, JA.; Mollá Romano, S.; Muñoz-Guerra, S.; Compañ Moreno, V. (2014). Configurational entropy calculation of poly(α-alkyl β,L-aspartate)s amorphous and crystalline films using gas permeation. European Polymer Journal. 59:254-261. https://doi.org/10.1016/j.eurpolymj.2014.07.024S2542615

    Excitatory effect of ATP on rat area postrema neurons

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    ATP-induced inward currents and increases in the cytosolic Ca2+ concentration ([Ca]in) were investigated in neurons acutely dissociated from rat area postrema using whole-cell patch-clamp recordings and fura-2 microfluorometry, respectively. The ATP-induced current (IATP) and [Ca]in increases were mimicked by 2-methylthio-ATP and ATP-γS, and were inhibited by P2X receptor (P2XR) antagonists. The current–voltage relationship of the IATP exhibited a strong inward rectification, and the amplitude of the IATP was concentration-dependent. The IATP was markedly reduced in the absence of external Na+, and the addition of Ca2+ to Na+-free saline increased the IATP. ATP did not increase [Ca]in in the absence of external Ca2+, and Ca2+ channel antagonists partially inhibited the ATP-induced [Ca]in increase, indicating that ATP increases [Ca]in by Ca2+ influx through both P2XR channels and voltage-dependent Ca2+ channels. There was a negative interaction between P2XR- and nicotinic ACh receptor (nAChR)-channels, which depended on the amplitude and direction of current flow through either channel. Current occlusion was observed at Vhs between −70 and −10 mV when the IATP and ACh-induced current (IACh) were inward, but no occlusion was observed when these currents were outward at a Vh of +40 mV. The IATP was not inhibited by co-application of ACh when the IACh was markedly decreased either by removal of permeant cations, by setting Vh close to the equilibrium potential of IACh, or by the addition of d-tubocurarine or serotonin. These results suggest that the inhibitory interaction is attributable to inward current flow of cations through the activated P2XR- and nAChR-channels

    Understandings of cervical screening in sexual minority women: A Q-methodological study

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    Discursive perspectives argue that cervical screening carries social and moral meaning. Overlooked by research into the health needs of sexual minority women, previous literature that has examined uptake of cervical screening has instead targeted increasing attendance via information and service provision. In order to explore the diversity of meanings that British sexual minority women have about cervical screening, the Q-sorts of 34 sexual minority women were factor analysed by-person and rotated to simple structure using Varimax. The five factors are interpreted and discussed relative to competing discourses on information provision within cervical screening. The five accounts are labelled 'cervical screening is': an essential health check that women have the right to refuse; a woman's health entitlement; a vital test but degrading experience; a sensible thing to do; and an unnecessary imposition for some women. Critical approaches to informed choice are explored with attention to recent developments in cervical cancer prevention. Findings highlighting the need for affirmation of diversity within healthcare are considered in relation to existing criteria for UK national screening programmes

    Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus

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    A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10-20), ER-negative BC (P=1.1 × 10-13), BRCA1-associated BC (P=7.7 × 10-16) and triple negative BC (P-diff=2 × 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10-3) and ABHD8 (P<2 × 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3′-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk
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