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991.
Effect of Biosurfactants on Laccase Production and Phenol Biodegradation in Solid-State Fermentation
Zhou MF Yuan XZ Zhong H Liu ZF Li H Jiang LL Zeng GM 《Applied biochemistry and biotechnology》2011,164(1):103-114
The effects of two biosurfactants, tea saponin (TS) and rhamnolipid (RL), on the production of laccase and the degradation
of phenol by P. simplicissimum were investigated in solid-state fermentation consisting of rice straw, rice bran, and sawdust. Firstly, the effects of phenol
on the fermentation process were studied in the absence of surfactants. Then, a phenol concentration of 3 mg/g in the fermentation
was selected for detailed research with the addition of biosurfactants. The results showed that TS and RL at different concentrations
had stimulative effects on the enzyme activity of laccase. The highest laccase activities during the fermentation were enhanced
by 163.7%, 68.2%, and 23.3% by TS at concentrations of 0.02%, 0.06%, and 0.10%, respectively. As a result of the enhanced
laccase activity, the efficiency of phenol degradation was also improved by both biosurfactants. RL caused a significant increase
of fungal biomass in the early stage of the fermentation, while TS had an inhibitory effect in the whole process. These results
indicated that RL could mitigate the negative effects of phenol on fungal growth and consequently improve laccase production
and phenol degradation. TS was potentially applicable to phenol-polluted solid-state fermentation. 相似文献
992.
在水热条件下,以对苯二甲基二膦酸为有机配体,以4,4'-联吡啶为辅助配体,合成了具有二维层状结构的有机膦酸镍化合物.晶体属于单斜晶系,C2/c空间群.该化合物每个金属中心与4个氧原子和2个氮原子配位,金属中心Nil通过4,4'-联吡啶配体相连,形成一维链状结构,再由有机膦酸连接形成了二维层状结构.通过灼烧可以除去化合物... 相似文献
993.
994.
A Small‐Molecule FRET Reporter for the Real‐Time Visualization of Cell‐Surface Proteolytic Enzyme Functions 下载免费PDF全文
Jing Mu Dr. Fang Liu Muhammad Shafiq Rajab Meng Shi Shuang Li Chiching Goh Prof. Lei Lu Prof. Qing‐Hua Xu Prof. Bin Liu Dr. Lai Guan Ng Prof. Bengang Xing 《Angewandte Chemie (International ed. in English)》2014,53(52):14357-14362
Real‐time imaging of cell‐surface‐associated proteolytic enzymes is critical to better understand their performances in both physiological and pathological processes. However, most current approaches are limited by their complexity and poor membrane‐anchoring properties. Herein, we have designed and synthesized a unique small‐molecule fluorescent probe, which combines the principles of passive exogenous membrane insertion and Förster resonance energy transfer (FRET) to image cell‐surface‐localized furin‐like convertase activities. The membrane‐associated furin‐like enzymatic cleavage of the peptide probe leads to an increased fluorescence intensity which was mainly localized on the plasma membrane of the furin‐expressed cells. This small‐molecule fluorescent probe may serve as a unique and reliable reporter for real‐time visualization of endogenous cell‐surfaceassociated proteolytic furin‐like enzyme functions in live cells and tissues using one‐photon and two‐photon microscopy. 相似文献
995.
Bridge‐Localized HOMO‐Binding Character of Divinylanthracene‐Bridged Dinuclear Ruthenium Carbonyl Complexes: Spectroscopic,Spectroelectrochemical, and Computational Studies 下载免费PDF全文
Ya‐Ping Ou Jing Zhang Meng Xu Jianlong Xia Prof. František Hartl Prof. Dr. Jun Yin Prof. Dr. Guang‐Ao Yu Prof. Dr. Sheng Hua Liu 《化学:亚洲杂志》2014,9(4):1152-1160
The electronic properties of four divinylanthracene‐bridged diruthenium carbonyl complexes [{RuCl(CO)(PMe3)3}2(μ? CH?CHArCH?CH)] (Ar=9,10‐anthracene ( 1 ), 1,5‐anthracene ( 2 ), 2,6‐anthracene ( 3 ), 1,8‐anthracene ( 4 )) obtained by molecular spectroscopic methods (IR, UV/Vis/near‐IR, and EPR spectroscopy) and DFT calculations are reported. IR spectroelectrochemical studies have revealed that these complexes are first oxidized at the noninnocent bridging ligand, which is in line with the very small ν(C?O) wavenumber shift that accompanies this process and also supported by DFT calculations. Because of poor conjugation in complex 1 , except oxidized 1+ , the electronic absorption spectra of complexes 2+ , 3+ , and 4+ all display the characteristic near‐IR band envelopes that have been deconvoluted into three Gaussian sub‐bands. Two of the sub‐bands belong mainly to metal‐to‐ligand charge‐transfer (MLCT) transitions according to results from time‐dependent DFT calculations. EPR spectroscopy of chemically generated 1+ – 4+ proves largely ligand‐centered spin density, again in accordance with IR spectra and DFT calculations results. 相似文献
996.
Dingrong Deng Dr. Yanjun Zhang Gen Li Xueyun Wang Dr. Li‐Hua Gan Dr. Li Jiang Prof. Chun‐Ru Wang 《化学:亚洲杂志》2014,9(5):1265-1269
Nanometer‐sized flakes of MnV2O6 were synthesized by a hydrothermal method. No surfactant, expensive metal salt, or alkali reagent was used. These MnV2O6 nanoflakes present a high discharge capacity of 768 mA h g?1 at 200 mA g?1, good rate capacity, and excellent cycling stability. Further investigation demonstrates that the nanoflake structure and the specific crystal structure make the prepared MnV2O6 a suitable material for lithium‐ion batteries. 相似文献
997.
One‐Step Hydrothermal Synthesis of Nitrogen‐Doped Carbon Nanotubes as an Efficient Electrocatalyst for Oxygen Reduction Reactions 下载免费PDF全文
Dr. Lisong Chen Dr. Xiangzhi Cui Dr. Yongxia Wang Min Wang Dr. Fangming Cui Dr. Chenyang Wei Dr. Weimin Huang Dr. Zile Hua Dr. Lingxia Zhang Prof. Jianlin Shi 《化学:亚洲杂志》2014,9(10):2915-2920
A high amount of heteroatom doping in carbon, although favorable for enhanced density of catalytically active sites, may lead to substantially decreased electroconductivity, which is necessary for the electrochemical oxygen reduction reaction. Herein, a relatively low amount of nitrogen was successfully doped into carbon nanotubes (CNTs) by a hydrothermal approach in one step, and the synthesized nitrogen‐doped CNT (CNT‐N) materials retained most of the original, excellent characteristics, such as the graphitic structure, tubular morphology, and high surface area, of CNTs. The resultant CNT‐N materials, although containing a relatively low amount of nitrogen doping, exhibited high electrocatalytic ORR activity, comparable to that of 20 wt % Pt/C; long durability; and, more importantly, largely inhibited methanol crossover effect. 相似文献
998.
Reactivity of Oxygen Radical Anions Bound to Scandia Nanoparticles in the Gas Phase: CH Bond Activation 下载免费PDF全文
Li‐Hua Tian Jing‐Heng Meng Dr. Xiao‐Nan Wu Dr. Yan‐Xia Zhao Dr. Xun‐Lei Ding Prof. Dr. Sheng‐Gui He Dr. Tong‐Mei Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(4):1167-1175
The activation of C?H bonds in alkanes is currently a hot research topic in chemistry. The atomic oxygen radical anion (O?.) is an important species in C?H activation. The mechanistic details of C?H activation by O?. radicals can be well understood by studying the reactions between O?. containing transition metal oxide clusters and alkanes. Here the reactivity of scandium oxide cluster anions toward n‐butane was studied by using a high‐resolution time‐of‐flight mass spectrometer coupled with a fast flow reactor. Hydrogen atom abstraction (HAA) from n‐butane by (Sc2O3)NO? (N=1–18) clusters was observed. The reactivity of (Sc2O3)NO? (N=1–18) clusters is significantly sizedependent and the highest reactivity was observed for N=4 (Sc8O13?) and 12 (Sc24O37?). Larger (Sc2O3)NO? clusters generally have higher reactivity than the smaller ones. Density functional theory calculations were performed to interpret the reactivity of (Sc2O3)NO? (N=1–5) clusters, which were found to contain the O?. radicals as the active sites. The local charge environment around the O?. radicals was demonstrated to control the experimentally observed size‐dependent reactivity. This work is among the first to report HAA reactivity of cluster anions with dimensions up to nanosize toward alkane molecules. The anionic O?. containing scandium oxide clusters are found to be more reactive than the corresponding cationic ones in the C?H bond activation. 相似文献
999.
Dr. Chunxiu Hua Dr. Xiangpeng Fang Prof. Zhaoxiang Wang Prof. Liquan Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(18):5487-5491
It is well accepted that metallic tin as a discharge (reduction) product of SnOx cannot be electrochemically oxidized below 3.00 V versus Li+/Li0 due to the high stability of Li2O, though a similar oxidation can usually occur for a transition metal formed from the corresponding oxide. In this work, nanosized Ni2SnO4 and NiO/SnO2 nanocomposite were synthesized by coprecipitation reactions and subsequent heat treatment. Owing to the catalytic effect of nanosized metallic nickel, metallic tin can be electrochemically oxidized to SnO2 below 3.00 V. As a result, the reversible lithium‐storage capacities of the nanocomposite reach 970 mAh g?1 or above, much higher than the theoretical capacity (ca. 750 mAh g?1) of SnO2, NiO, or their composites. These findings extend the well‐known electrochemical conversion reaction to non‐transition‐metal compounds and may have important applications, for example, in constructing high‐capacity electrode materials and efficient catalysts. 相似文献
1000.
Metal‐Free Oxidative Radical Addition of Carbonyl Compounds to α,α‐Diaryl Allylic Alcohols: Synthesis of Highly Functionalized Ketones 下载免费PDF全文
Xue‐Qiang Chu Hua Meng You Zi Prof. Dr. Xiao‐Ping Xu Prof. Dr. Shun‐Jun Ji 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(51):17198-17206
A metal‐free direct alkylation of simple carbonyl compounds (ketones, esters, and amides) with α,α‐diaryl allylic alcohols is described. The protocol provides facile access to highly functionalized dicarbonyl ketones by a radical addition/1,2‐aryl migration cascade. The regioselectivity of the reaction was precisely controlled by the nature of the carbonyl compound. 相似文献