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排序方式: 共有624条查询结果,搜索用时 312 毫秒
31.
Manuela Zanetti Devid Maniglio Cristian Fasoli Marco Pola Elisa Borga Claudio Corradi Mauro Dalla Serra Salvatore Iannotta Antonella Motta Tullio Toccoli 《Electroanalysis》2014,26(8):1653-1659
We report the fabrication of a microfluidic apparatus and the realization of a sensors based on PEDOT : PSS, a biocompatible semiconductor polymer used in substitution of standard electrodes for electrophysiological studies and for detection of nanopores in membrane. This gives the possibility to study the mechanisms of ions balance and molecular transport though cell membranes. In particular the apparatus is based on two chambers connected through an aperture in a PTFE sheet where lipid bilayer are formed using Montal‐Mueller method, and the pore‐forming proteins activity is detected by polymeric electrodes. This methodology could be applied to examine different membrane proteins for the purpose of biosensing, drug screening and nanopore technologies. 相似文献
32.
A new thiosemicarbazone compound derived from 1-phenyl-3-methyl-4-(2-thenoyl) pyrazolone-5(HPMTP) and thiosemicarbazide has been synthesized and characterized by IR, HNMR, MS, elemental analysis, UV and single-crystal X-ray diffraction. The compound crystallizes in monoclinic system, Cc space group with a = 7.5925(8), b = 20.263(2), c = 11.4669(13) , = 107.825(8)°, V = 1679.5(3) 3, Z = 4, R = 0.0316 and wR = 0.0687. The results of antibacterial activity test against Escherichia coli and Bacillus subtilis indicate that the compound possesses the same antibacterial activity as the contrast(Norfloxacin). Theoretical study of the forming mechanism to the title compound at the RHF/6-31G(d) level shows that there are two steps. The distal amino group of thiosemicarbazide is added to the 4-carbonyl group of HPMTP which forms TM. Then a dehydration reaction occurs in TM and generates a stable product PC. 相似文献
33.
Construction of 3D tissues by various types of cells with specific characteristics is an important and fundamental technology in tissue reconstruction medicine and animal‐free diagnosis system. To do so, an excellent extracellular matrix (ECM) is needed for encapsulation of cells and maintaining cell activity. Spontaneously forming hydrogel matrix is used by complexation between two water‐soluble polymers, 2‐methacryloyloxyethyl phosphorylcholine polymer bearing phenylboronic acid groups and poly(vinyl alcohol). Two cytokines for cell proliferation are immobilized in the hydrogel matrix to control the activities of the encapsulated cells. The cytokine‐immobilized hydrogel matrix can encapsulate both L929 fibroblasts and normal human dermal fibroblasts under mild condition. The physical properties of the hydrogel matrix can follow the proliferation process of the encapsulated cells. The encapsulated cells secrete ECM in the polymer hydrogel networks upon 3D culturing for 7 days. Consequently, the tissue‐mimicking ECM hybrid hydrogels are fabricated successfully. 相似文献
34.
Pd80+x
Si20−x
(x = 0, 1, and 2) binary metallic glasses with the diameter ranging from 7 to 8 mm were prepared by a combination of fluxing
and water quenching or air cooling. Thermal analysis results show that with increasing Si content, the glass transition temperature
T
g, the initial crystallization temperature T
x and the onset crystallization temperature T
p of Pd-Si binary glassy alloys increase. Moreover, the supercooled liquid region reaches 61 K. It indicates that Pd-Si binary
alloys possess large glass forming ability, which can be greatly improved by fluxing treatment.
Supported by the National Basic Research Program of China (Grant No. 2007CB613905) and the National Natural Science Foundation
of China (Grant Nos. 50671050 and 50431030) 相似文献
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37.
针对螺旋线型脉冲形成线放电过程的匝间击穿问题,采用数值模拟的方法研究了影响螺旋线上轴向电场的因素,模拟结果表明:螺旋线的螺旋角越大、开关的上升沿越小、负载的阻值越小则越容易造成匝间击穿;针对输出波形的前沿上冲和下凹问题,通过数值模拟和实验方法研究了加速器内阻抗不匹配段对输出波形的影响,结果表明: 改变螺旋线与开关之间连接段的阻抗以及开关和二极管之间过渡段的阻抗,使之接近于螺旋线阻抗,并使电长度减小,可以消除波形的前沿上冲和下凹,得到近似方波的高电压脉冲输出。 相似文献
38.
Free energies of transfer (ΔGt) of RibonucleaseA (RNaseA) from water to aqueous solutions of urea (4 M, 6 M and 8 M), a protein denaturing solvent as well as ΔGt of RibonucleaseA, β‐Lactoglobulin, α‐Chymotripsin and ChymotrypsinogenA from water to aqueous glycerol (10%, 20%, 30% and 40%), a protein stabilizing solvent has been dissected into cavity term [ΔGt(cav)] and interaction term [ΔGt(int)]. The interaction free energy includes all types of interactions like hard‐soft, hydrogen bonding, electrostatic, etc. The cavity forming free energies have been calculated using the standard version of scaled particle theory (SPT) with well‐reported SPT parameters. It has been found that transfer free energies of cavity terms ΔGt(cav) for native protein from water to urea‐water and water to aqueous glycerol follow almost opposite trends. This primarily indicates there may be some correlation between cavity creation energies and protein denaturing and stabilizing ability of a solvent. The results are in agreement with those obtained from preferential binding coefficient studies in these media. 相似文献
39.
Film forming kinetics and reaction mechanism of γ-glycidoxypropyltrimethoxysilane on low carbon steel surfaces 总被引:1,自引:0,他引:1
The film forming kinetics and reaction mechanism of γ-GPS on low carbon steel surfaces was investigated by FTIR-ATR, AFM, NSS and theoretical calculation method. The results from experimental section indicated that the reaction of γ-GPS on low carbon steel surfaces followed the conventional reaction mechanism, which can be described as reaction (I) (Me (Metal)-OH + HO-Si → Me-O-Si + H2O) and reaction (II) (Si-OH + Si-OH → Si-O-Si + H2O). During film forming process, the formation of Si-O-Fe bond (reaction (I)) exhibited oscillatory phenomenon, the condensation degree of silanol monomers (reaction (II)) increased continuously. The metal hydroxyl density had significant influence on the growth mechanisms and corrosion resisting property of γ-GPS films. The results from theoretical calculation section indicated that the patterns of reaction (I) and reaction (II) were similar, involving a nucleophilic attack on the silicon center. The formation of Si-O-Fe bond (reaction (I)) was kinetically and thermodynamically preferred, which had catalytic effect on its condensation with neighboring silanol monomers (reaction (II)). Our DFT calculations were good consistent with the experimental measurements. 相似文献
40.