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排序方式: 共有3454条查询结果,搜索用时 15 毫秒
91.
Sam J. Dahman 《Polymer Engineering and Science》1999,39(11):2181-2188
Using a combination of functionalized dopants was found to be a simple method to improve the processability of intrinsically conducting polymers while retaining relatively high levels of conductivity. Two intrinsically conducting polymers, poly(3-octylthiophene) and polyaniline were co-doped with various combinations of dopants. In both systems, solubility was improved and coherent films were formed directly from common organic solvents without the need for a post-processing doping step. Co-doped intrinsically conducting polymer films exhibited conductivities up to 10?2 S/cm. Additionally, certain polyaniline complexes were capable of being melt processed without loss of conductivity. 相似文献
92.
The inhibition of mild steel corrosion in aerated 0.5 N H2SO4 solution was investigated using potentiodynamic polarization studies (Tafel), linear polarization studies, electrochemical impedance spectroscopy studies, adsorption studies, and surface morphological studies. The effect of inhibitor concentration on corrosion rate, the effect of temperature, degree of surface coverage, adsorption kinetics, and surface morphology are investigated. The inhibition efficiency increased markedly with increase in the additive concentration and decreased slightly with increasing temperature. The presence of DMSTT decrease the double-layer capacitance and increase the charge transfer resistance. The value of activation energy (E a) of metal corrosion, adsorption equilibrium constant (K ads), and free energy of adsorption (ΔG ads) were calculated from the temperature dependence of corrosion current. The adsorption of inhibitor molecule on mild steel surface follow Langmuir isotherm. DMSTT offers excellent inhibition properties and acts as a mixed-type inhibitor. 相似文献
93.
Jin-Xian Liao Yu-Wei Chen Ming-Kuei Shih You-Lin Tain Yao-Tsung Yeh Min-Hsi Chiu Sam K. C. Chang Chih-Yao Hou 《International journal of molecular sciences》2021,22(10)
Resveratrol can affect the physiology or biochemistry of offspring in the maternal–fetal animal model. However, it exhibits low bioavailability in humans and animals. Fifteen-week SD pregnant female rats were orally administered bisphenol A (BPA) and/or resveratrol butyrate ester (RBE), and the male offspring rats (n = 4–8 per group) were evaluated. The results show that RBE treatment (BPA + R30) compared with the BPA group can reduce the damage caused by BPA (p < 0.05). RBE enhanced the expression of selected genes and induced extramedullary hematopoiesis and mononuclear cell infiltration. RBE increased the abundance of S24-7 and Adlercreutzia in the intestines of the male offspring rats, as well as the concentrations of short-chain fatty acids (SCFAs) in the feces. RBE also increased the antioxidant capacity of the liver by inducing Nrf2, promoting the expression of HO-1, SOD, and CAT. It also increased the concentration of intestinal SCFAs, enhancing the barrier formed by intestinal cells, thereby preventing BPA-induced metabolic disruption in the male offspring rats, and reduced liver inflammation. This study identified a potential mechanism underlying the protective effects of RBE against the liver damage caused by BPA exposure during the peri-pregnancy period, and the influence of the gut microbiota on the gut–liver axis in the offspring. 相似文献
94.
Peter Cuthbertson Nicholas J. Geraghty Sam R. Adhikary Katrina M. Bird Stephen J. Fuller Debbie Watson Ronald Sluyter 《International journal of molecular sciences》2021,22(15)
Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a curative therapy for blood cancers and other haematological disorders. However, allo-HSCT leads to graft-versus-host disease (GVHD), a severe and often lethal immunological response, in the majority of transplant recipients. Current therapies for GVHD are limited and often reduce the effectiveness of allo-HSCT. Therefore, pro- and anti-inflammatory factors contributing to disease need to be explored in order to identify new treatment targets. Purinergic signalling plays important roles in haematopoiesis, inflammation and immunity, and recent evidence suggests that it can also affect haematopoietic stem cell transplantation and GVHD development. This review provides a detailed assessment of the emerging roles of purinergic receptors, most notably P2X7, P2Y2 and A2A receptors, and ectoenzymes, CD39 and CD73, in GVHD. 相似文献
95.
Qi Hui Sam Hua Ling Wen Shan Yew Zhaohong Tan Sharada Ravikumar Matthew Wook Chang Louis Yi Ann Chai 《International journal of molecular sciences》2021,22(12)
Fatty acids are derived from diet and fermentative processes by the intestinal flora. Two to five carbon chain fatty acids, termed short chain fatty acids (SCFA) are increasingly recognized to play a role in intestinal homeostasis. However, the characteristics of slightly longer 6 to 10 carbon, medium chain fatty acids (MCFA), derived primarily from diet, are less understood. Here, we demonstrated that SCFA and MCFA have divergent immunomodulatory propensities. SCFA down-attenuated host pro-inflammatory IL-1β, IL-6, and TNFα response predominantly through the TLR4 pathway, whereas MCFA augmented inflammation through TLR2. Butyric (C4) and decanoic (C10) acid displayed most potent modulatory effects within the SCFA and MCFA, respectively. Reduction in TRAF3, IRF3 and TRAF6 expression were observed with butyric acid. Decanoic acid induced up-regulation of GPR84 and PPARγ and altered HIF-1α/HIF-2α ratio. These variant immune characteristics of the fatty acids which differ by just several carbon atoms may be attributable to their origins, with SCFA being primarily endogenous and playing a physiological role, and MCFA exogenously from the diet. 相似文献
96.
Soon-?Sam?Hong ShinHyoung?KangEmail author 《Journal of Mechanical Science and Technology》2002,16(9):1147-1155
Discharge flows from a centrifugal pump impeller with a specific speed of 150 [rpm, m3/min, m] were experimentally investigated. A large axisymmetric collector instead of a volute casing was installed to obtain
circumferentially uniform flow, i.e. without interaction of the impeller and the volute. The unsteady flow was measured at
the impeller exit and vaneless diffuser using a hot film probe and a pressure transducer. The flow at impeller exit showed
pronounced jet-wake flow patterns. The wake, which was on the suction/hub side at high flow rate, became enlarged pitchwisely
on both the hub and the shroud side as the flow rate decreases. The pitchwise non-uniformity of the flow rapidly decreased
along the downstream and the nonuniformity almost disappeared at radius ratio of 1.18 for medium flow rate. The mean vaneless
diffuser flow was reasonably predicted using a one dimensional analysis when an empirical constant was used to specify the
skin friction coefficient. The data can be used for a centrifugal pump impeller design and validation of CFD codes and flow
modeling. 相似文献
97.
Zhang Yuanyin Sam Zandong Sun Yang Haijun Wang Haiyang Han Jianf Gao Hongliang Luo Chunshu Jing Bing 《石油科学(英文版)》2011,8(4):415-421
The major storage space types in the carbonate reservoir in the Ordovician in the TZ45 area are secondary dissolution caves.For the prediction of caved carbonate reservoir,post-stack methods are commonly used in the oilfield at present since pre-stack inversion is always limited by poor seismic data quality and insufficient logging data.In this paper,based on amplitude preserved seismic data processing and rock-physics analysis,pre-stack inversion is employed to predict the caved carbonate reservoir in TZ45 area by seriously controlling the quality of inversion procedures.These procedures mainly include angle-gather conversion,partial stack,wavelet estimation,low-frequency model building and inversion residual analysis.The amplitude-preserved data processing method can achieve high quality data based on the principle that they are very consistent with the synthetics.Besides,the foundation of pre-stack inversion and reservoir prediction criterion can be established by the connection between reservoir property and seismic reflection through rock-physics analysis.Finally,the inversion result is consistent with drilling wells in most cases.It is concluded that integrated with amplitude-preserved processing and rock-physics,pre-stack inversion can be effectively applied in the caved carbonate reservoir prediction. 相似文献
98.
Several existing formulas for the initial porosity and settling velocity of sediment have been tested by using extensive data collected from different countries and regions, and modified to achieve better reliability or convenience in use. 相似文献
99.
100.