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91.
92.
Reduced nitric oxide synthase and cyclo-oxygenase activity in the uterus of non-obese diabetic mice 总被引:1,自引:0,他引:1
Roca V Larocca L Calafat M Aisemberg J Meiss R Franchi AM Leirós CP 《Reproduction (Cambridge, England)》2006,132(6):931-938
A functional interaction between progesterone, Th2 cytokines and a suitable balance between nitric oxide and prostaglandins in the uterus is considered to have a major role in the success of embryo implantation and pregnancy. Non-obese diabetic (NOD) mice offer a suitable model to study the modulatory role of Th1 cytokines on uterus signalling and function, since at the prediabetic stage they develop a spontaneous Th1 autoimmune response against exocrine glands similar to Sj?gren's syndrome. Vasoactive intestinal peptide (VIP) is a vasoactive neuro- and immunopeptide that promotes Th2 profiles and contributes to the smooth muscle relaxation and vasodilation. The aim of the present study was to investigate the activities of nitric oxide synthase and cyclo-oxygenase and the effect of VIP in the uterus of NOD mice with an emerging Th1 cytokine response. We present evidence of a reduced basal and VIP-stimulated activity of both enzymes in the uterus of NOD mice compared with normal BALB/c mice in proestrus. An altered functional interaction between both enzymes is also present in NOD mice at the time when increased levels of serum interleukin (IL)-12 and tumour necrosis factor-alpha but not interferon (IFN)-gamma or IL-10 were detected. We conclude that signalling alterations in uteri of NOD mice are simultaneous to the onset of a systemic Th1 cytokine response. 相似文献
93.
Although zeolites are introduced to decrease methanol crossover of Nafion membranes for direct methanol fuel cells (DMFCs), little is known about the effect of their intrinsic properties and the interaction with the ionomer. In this work, Nafion-Faujasite composite membranes prepared by solution casting were characterized by extensive physicochemical and electrochemical techniques. Faujasite was found to undergo severe dealumination during the membrane activation, but its structure remained intact. The zeolite interacts with Nafion probably through hydrogen bonding between Si-OH and SO3H groups, which combined with the increase of the water uptake and the water mobility, and the addition of a less conductive phase (the zeolite) leads to an optimum proton conductivity between 0.98 and 2 wt% of zeolite. Hot pressing the membranes before their assembling with the electrodes enhanced the DMFC performance by reducing the methanol crossover and the serial resistance. 相似文献
94.
Toschi F Orlanducci S Tamburri E Guglielmotti V Terranova ML Di Carlo A Reale A Falessi C 《Journal of nanoscience and nanotechnology》2010,10(12):8336-8340
The thermal performances of nanocomposite layers formed by Single-walled Carbon Nanotubes (SWCNT) dispersed in 2 different kind of polydimethyl-siloxane (PDMSO) matrices has been investigated by measuring the thermal resistance under conditions similar to the ones used for thermal management in microelectronics. A series of nanocomposite samples with thickness in the range 25 microm(-1) cm have been tested. The nanocomposites were prepared varying the amounts of nanotubes embedded in the matrix (from 0.1 to 5%w). In some cases also microsized graphites were mixed to the nanotube's fillers. For 25 micron thick layers, the thermal resistance of the neat silicone specimen can be reduced of 54% with the addition of 2%w carbon nanotubes. The variation of thermal conductivity as a function of the SWCNT's loading is reported and discussed. Furthermore the dispersion's effects of the nanotubes in the layers and the effects on the realization of a net-like system have been investigated. 相似文献
95.
Effect of seasonal climate fluctuations on the evolution of glycoconjugates during the ripening period of grapevine cv. Muscat à petits grains blancs berries 下载免费PDF全文
96.
Ruffolo Silvestro A. La Russa Mauro F. Ricca Michela Belfiore Cristina M. Macchia Andrea Comite Valeria Pezzino Antonino Crisci Gino M. 《Bulletin of Engineering Geology and the Environment》2017,76(1):11-20
Bulletin of Engineering Geology and the Environment - The deterioration of a stone material is related to its pore structure, which affects the interaction between surface and environmental agents.... 相似文献
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Sensory Analysis and Consumers Studies of Açai Beverage After Thermal,Chlorine and Ozone Treatments of the Fruits 下载免费PDF全文
100.
Alessandra Gentili Valeria De Pratti Fulvia Caretti Virginia Pérez-Fernández Pierpaolo Tomai Roberta Curini 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2016,33(12):1793-1802
This paper describes a rapid method for confirming residues of thyreostats in meat-based baby foods by using liquid chromatography – dual polarity electrospray – tandem mass spectrometry (LC-ES(±)-MS/MS). Six thioureylenes, belonging to the group of thiouracil and imidazole, were selected for this work: thiouracil (TU), methylthiouracil (MTU), propylthiouracil (PTU), phenylthiouracil (PhTU), mercaptobenzimidazole (MBI) and tapazole (TAP).The amphoteric nature of these compounds allows their electrospray detection in both positive and negative ionisation. Nevertheless, MS detection is not favoured by their low molecular weights, while their chromatographic retention is also thwarted by their high polarity. A pentafluorophenyl (PFP) core-shell phase column was selected to avoid peak asymmetry or peak splitting, and a dual-polarity ionisation method was optimised to obtain a sensitivity as high as possible. The method was validated according to the Commission Decision 657/2002/EC. A simple and fast procedure based on matrix solid phase dispersion (MSPD) was optimised to extract analytes from baby foods with recoveries exceeding 82%. Limit of decision (CCα) and detection capability (CCβ) were lower than the permissible maximum concentration (10 ng g?1). The validated method was then applied to assess the potential occurrence of the six selected thyreostats in nine commercial products. All the samples were found free of contamination. 相似文献