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121.
Dr. Yongqi Huang Prof. Zhirong Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(14):4462-4467
Specific protein–protein interactions are critical to cellular function. Structural flexibility and disorder‐to‐order transitions upon binding enable intrinsically disordered proteins (IDPs) to overcome steric restrictions and form complementary binding interfaces, and thus, IDPs are widely considered to have high specificity and low affinity for molecular recognition. However, flexibility may also enable IDPs to form complementary binding interfaces with misbinding partners, resulting in a great number of nonspecific interactions. Consequently, it is questionable whether IDPs really possess high specificity. In this work, we investigated this question from a thermodynamic viewpoint. We collected mutant thermodynamic data for 35 ordered protein complexes and 43 disordered protein complexes. We found that the enthalpy–entropy compensation for disordered protein complexes was more complete than that for ordered protein complexes. We further simulated the binding processes of ordered and disordered protein complexes under mutations. Simulation data confirmed the observation of experimental data analyses and further revealed that disordered protein complexes possessed smaller changes in binding free energy than ordered protein complexes under the same mutation perturbations. Therefore, interactions of IDPs are more malleable than those of ordered proteins due to their structural flexibility in the complex. Our results provide new clues for exploring the relationship between protein flexibility, adaptability, and specificity. 相似文献
122.
Dr. Kuaibing Wang Xiaoyan Ma Zhiyang Zhang Dr. Mingbo Zheng Zhirong Geng Prof. Dr. Zhilin Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7084-7089
Carbon‐coated Mn3O4 nanowires (Mn3O4@C NWs) have been synthesized by the reduction of well‐shaped carbon‐coated bixbyite networks and characterized by TEM, X‐ray diffraction, X‐ray photoelectron spectroscopy, and electrochemical experiments. To assess the properties of 1D carbon‐coated nanowires for their use in supercapacitors, cyclic voltammetry and galvanostatic charging–discharging measurements were performed. Mn3O4@C NWs could be charged and discharged faster and had higher capacitance than bare Mn3O4 nanostructures and other commercial materials. The capacitance of the Mn3O4@C NWs was 92 % retained after 3000 cycles at a charging rate of 5 A g?1. This improvement can be attributed to the carbon shells, which promote fast Faradaic charging and discharging of the interior Mn3O4 core and also act as barriers to protect the inner core. These Mn3O4@C NWs could be a promising candidate material for high‐capacity, low‐cost, and environmentally friendly electrodes for supercapacitors. In addition, the magnetic properties of the as‐synthesized samples are also reported to investigate the influence of the carbon coating. 相似文献
123.
Limin Zhou Yuyan Jia Juan Peng Zhirong Liu Essam Al-Zaini 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):331-340
The triphosphate-crosslinked magnetic chitosan resins (TPP-MCR) with a diameter range of 200–350 nm were synthesized for the adsorption of U(VI) and Th(IV) ions from aqueous solutions. The adsorption experiments were conducted in both mono-component systems with pure actinide solution and bi-component systems with different U/Th mass ratios. The maximum adsorption capacities in mono-component systems determined by Langmuir model were 169.5 and 146.8 mg g?1 for U(VI) and Th(IV), respectively. In bi-component systems, U(VI) and Th(IV) adsorption capacities were reduced significantly, and the combined sorption capacities were substantially lower (almost halved) compared to those obtained by the addition of sorption capacities using mono-component solutions, indicating that U(VI) and Th(IV) compete for the same sorption sites. Adsorption–desorption experiments for five cycles illustrated the feasibility of the repeated use of TPP-MCR for the adsorption of U(VI) and Th(IV) ions. 相似文献
124.
Zhenyou Li Bhaghavathi P. Vinayan Piotr Jankowski Christian Njel Ananyo Roy Tejs Vegge Julia Maibach Juan Maria García Lastra Maximilian Fichtner Zhirong Zhao‐Karger 《Angewandte Chemie (International ed. in English)》2020,59(28):11483-11490
The development of multivalent metal (such as Mg and Ca) based battery systems is hindered by lack of suitable cathode chemistry that shows reversible multi‐electron redox reactions. Cationic redox centres in the classical cathodes can only afford stepwise single‐electron transfer, which are not ideal for multivalent‐ion storage. The charge imbalance during multivalent ion insertion might lead to an additional kinetic barrier for ion mobility. Therefore, multivalent battery cathodes only exhibit slope‐like voltage profiles with insertion/extraction redox of less than one electron. Taking VS4 as a model material, reversible two‐electron redox with cationic–anionic contributions is verified in both rechargeable Mg batteries (RMBs) and rechargeable Ca batteries (RCBs). The corresponding cells exhibit high capacities of >300 mAh g?1 at a current density of 100 mA g?1 in both RMBs and RCBs, resulting in a high energy density of >300 Wh kg?1 for RMBs and >500 Wh kg?1 for RCBs. Mechanistic studies reveal a unique redox activity mainly at anionic sulfides moieties and fast Mg2+ ion diffusion kinetics enabled by the soft structure and flexible electron configuration of VS4. 相似文献
125.
Junhui Li Yanan Wang Wenzhi Jia Zhiwen Xi Huanhui Chen Zhirong Zhu Zhonghua Hu 《天然气化学杂志》2014,(6):771-780
The external surface of HZSM-5 zeolite was passivated by liquid siliceous deposition and by acidic sites poisoning with lepidine, respectively. Then methanol-to-hydrocarbons (MTH) reaction was investigated over the above as-prepared catalysts and the dissoluble coke on these used catalysts was analyzed by GC-MS, to study the role of the external surface of HZSM-5 in the catalytic reaction. Comparison with the experi- mental results based on parent ZSM-5 showed that the product distribution of MTH reaction was obviously influenced by the external surface. Evidences were listed as follows: (1) the final product on parent HZSM-5 showed higher aromatic selectivity, lower olefin selectivity, lower ra- tio of C2/C3+ aliphatics and higher ratio of C3/C4+ aliphatics than the reaction mixture produced by the sole catalysis of acidic sites in HZSM-5 channel; (2) a little of pentamethylbenzene and hexamethylbenzene in the product on parent HZSM-5, was produced via multi-methylation of methylbenzene on the external surface. The above conclusion may also be suitable for MTH reaction over other zeolites with 10-ring channel. 相似文献
126.
催化动力学光度法测定痕量铂的研究 总被引:6,自引:0,他引:6
利用痕量铂在稀硫酸介质中对溴酸钾氧化酸性铬蓝K的催化作用,建立了催化动力学光度法测定痕量铂的新方法。方法的线性范围为0-0.8μg/25mL,检出限为7.93×10^-11g/mL。用于合成样品及含铂催化剂中铂的测定,结果满意。 相似文献
127.
经人外周血淋巴细胞姊妹染色单体互换、小鼠骨髓细胞的染色体畸变分析,以及致哺乳动物的嗜多染红细胞的微核发生试验,研究了不同性质的生化灭鼠剂对人和小鼠体细胞的致突变性.结果表明,无论生化灭鼠剂是否具生理毒性,对人和小白鼠体细胞均不具致突变性 相似文献
128.
通过热模拟试验研究了COREX竖炉气体利用率与还原条件的关系及工业竖炉可达到的气体利用率极限.研究了熔炼煤耗与还原参数的内在联系及达到最低能耗的优化条件.结果表明,竖炉气体利用率受热力学和动力学混合控制,最高值约为50%左右.全流程最低能耗与熔炼煤性质有关.使用发热值为29kJg-1的2号熔炼煤时,最低煤耗为624kg,净能耗为2.054×107J. 相似文献
129.
采用变激发功率密度下的光致发光,变温下的光致发光等手段,研究了混晶GaAs1-xPx:N(x=0.4)样品中各发光带的发光特性,比较了不同激发条件下Nr与Nx发光带的不同行为,求得在不同的温度区间内,Nг及Nx不同的激活能,结果表明Nг与Nx分属不同的杂质发光中心,有着不同的束缚激子的机制. 相似文献
130.
本文介绍了灰土桩消除黄土地基湿陷性的施工监理组织、方法、程序等,着重探讨了灰土桩监理的4MIE,通过“事前控制、事中控制、事后控制”,结合测试数据,充分证明:通过有效的监理,使灰土桩消除黄土湿陷性达到了预期的处理效果。 相似文献