The Comparison of Information Systems Develop Trends between the Chinese Mainland and International

The aims of this research are two fold. First, it compares the research focus of Information Systems in Mainland China with that of the international IS research community. Second, the paper describes the main features and trend of IS research in Mainland China, and makes some suggestions as to some possible interesting research arena. The data are from twenty five academic journals in China and proceedings of international Information Systems conferences

Influence of WeChat Use on the College Students Campus Life Satisfaction-A Perspective on Bridging Social Capital

The theories of social capital and Rosenberg's self-esteem scale were used to measure the campus life satisfaction of college students, this paper made an empirical analysis on the WeChat media use of 1000 college students from Hong Kong, Macao, Taiwan and mainland China (M=18.81 years old, SD=0.96) of a University in Guangdong province, and discussed the relationship among college students' social media use intensity, campus life satisfaction and social capital. The study found that there was a significant positive correlation between WeChat use intensity of college students and social capital, that the intensity of WeChat use had a direct effect on college students' satisfaction with campus life, and that self-esteem had a moderating effect between WeChat use intensity and social capital

Transcriptional Regulation of PP2A-Aα Is Mediated by Multiple Factors Including AP-2α, CREB, ETS-1, and SP-1

Protein phosphatases-2A (PP-2A) is a major serine/threonine phosphatase and accounts for more than 50% serine/threonine phosphatase activity in eukaryotes. The holoenzyme of PP-2A consists of the scaffold A subunit, the catalytic C subunit and the regulatory B subunit. The scaffold subunits, PP2A-Aα/β, provide a platform for both C and B subunits to bind, thus playing a crucial role in providing specific PP-2A activity. Mutation of the two genes encoding PP2A-Aα/β leads to carcinogenesis and likely other human diseases. Regulation of these genes by various factors, both extracellular and intracellular, remains largely unknown. In the present study, we have conducted functional dissection of the promoter of the mouse PP2A-Aα gene. Our results demonstrate that the proximal promoter of the mouse PP2A-Aα gene contains numerous cis-elements for the binding of CREB, ETS-1, AP-2α, SP-1 besides the putative TFIIB binding site (BRE) and the downstream promoter element (DPE). Gel mobility shifting assays revealed that CREB, ETS-1, AP-2α, and SP-1 all bind to PP2A-Aα gene promoter. In vitro mutagenesis and reporter gene activity assays reveal that while SP-1 displays negative regulation, CREB, ETS-1 and AP-2Aα all positively regulate the promoter of the PP2A-Aα gene. ChIP assays further confirm that all the above transcription factors participate the regulation of PP2A-Aα gene promoter. Together, our results reveal that multiple transcription factors regulate the PP2A-Aα gene

Biocatal. Biotransform.

Glycerol dehydrogenase (GlyDH) which oxidizes glycerol to the value-added chemical, 1,3-dihydroxyacetone, is of interest due to the oversupply of glycerol as a by-product of the biodiesel industry. To exploit the enzymatic oxidation of glycerol industrially, silica coated magnetic Fe(3)O(4) nanoparticles were prepared and then activated with an amino-silane reagent for covalent immobilization of GlyDH via a glutaraldehyde linkage. At the optimal glutaraldehyde concentration of 0.05% (v/v), an enzyme loading of up to 57.5 mg/g-nanoparticles was achieved with 81.1% of the original activity retained. Reaction kinetic analysis indicated that the immobilized GlyDH had almost the same Michaelis-Menten constants for both NAD(+) and glycerol as the free GlyDH did. However, after immobilization the turnover number k(cat) of the GlyDH decreased from 164 s(-1) to 113 s(-1), and the reaction was 1.3-fold less sensitive to inhibition by DHA, which could compensate the decrease in k(cat). The immobilized GlyDH was also less sensitive to changes in pH and temperature, and showed a 5.3-fold improvement in thermal stability at 50 degrees C. Furthermore, excellent reusability was observed such that 10 cycles of re-use only led to 9% loss of enzyme activity.Glycerol dehydrogenase (GlyDH) which oxidizes glycerol to the value-added chemical, 1,3-dihydroxyacetone, is of interest due to the oversupply of glycerol as a by-product of the biodiesel industry. To exploit the enzymatic oxidation of glycerol industrially, silica coated magnetic Fe(3)O(4) nanoparticles were prepared and then activated with an amino-silane reagent for covalent immobilization of GlyDH via a glutaraldehyde linkage. At the optimal glutaraldehyde concentration of 0.05% (v/v), an enzyme loading of up to 57.5 mg/g-nanoparticles was achieved with 81.1% of the original activity retained. Reaction kinetic analysis indicated that the immobilized GlyDH had almost the same Michaelis-Menten constants for both NAD(+) and glycerol as the free GlyDH did. However, after immobilization the turnover number k(cat) of the GlyDH decreased from 164 s(-1) to 113 s(-1), and the reaction was 1.3-fold less sensitive to inhibition by DHA, which could compensate the decrease in k(cat). The immobilized GlyDH was also less sensitive to changes in pH and temperature, and showed a 5.3-fold improvement in thermal stability at 50 degrees C. Furthermore, excellent reusability was observed such that 10 cycles of re-use only led to 9% loss of enzyme activity

Research on the Effectiveness of China’s Macro Control Policy on Output and Technological Progress under Economic Policy Uncertainty

The uncertainty of economic policy, a specific form of uncertainty, can affect both economic growth, and the effectiveness of the macroeconomic regulation and control policy. Existing studies have analyzed the impacts of economic policy uncertainty on investment, consumption, trade, and total factor survival, but there is no analysis of the effectiveness of macroeconomic regulation and control policies on output and technological progress in a deterministic environment. Output growth and technological progress show the performance of economic growth in gross and efficiency, respectively, which is the external performance and internal driving force of economic growth. To achieve long-term sustainable economic development, it is necessary to consider both the aggregate problem and technological progress. In this context, this paper attempts to explore the effectiveness of China’s macroeconomic regulation and control policy on output growth and technological progress under the economic policy uncertainty. Specifically, this paper first analyzes the effectiveness of macroeconomic regulation and control policy on China’s output growth and technological progress in an uncertain environment, and then makes an empirical study by constructing a time-varying parameter vector autoregression model (TVP-VAR). Furthermore, the simulation test of the relevant results is carried out using the counter-fact analysis method. The empirical results show that: (1) under the uncertainty environment, the direction of the effect of price monetary policy on output has not changed, the effect of interest rate increase on output growth is negative, and the impact is stronger in the short term than in the medium and long term; the effect of rising interest rates on technological progress is positive, and the effect intensity is also significant in the short term, but weak in the medium and long term, the effect of price monetary policy on output is stronger under moderate uncertainty. (2) Credit growth can promote output growth, and the regulation effect of credit growth on output growth is mainly reflected in the short term under the TVP-VAR model, the effect of credit growth on technological progress is not significant. Further research using counterfactual analysis shows that the uncertain environment will reduce the effect of credit policy on output growth, but the effect is not significant

Effect of molecular mobility on coupled enzymatic reactions involving cofactor regeneration using nanoparticle-attached enzymes

Cofactor-dependent multi-step enzymatic reactions generally require dynamic interactions among cofactor, enzyme and substrate molecules. Maintaining such molecular interactions can be quite challenging especially when the catalysts are tethered to solid state supports for heterogeneous catalysis for either biosynthesis or biosensing. The current work examines the effects of the pattern of immobilization, which presumably impacts molecular interactions on the surface of solid supports, on the reaction kinetics of a multienzymic system including glutamate dehydrogenase, glucose dehydrogenase and cofactor NAD(H). Interestingly, particle collision due to Brownian motion of nanoparticles successfully enabled the coupled reactions involving a regeneration cycle of NAD(H) even when the enzymes and cofactor were immobilized separately onto superparamagnetic nanoparticles (124 nm). The impact of particle motion and collision was evident in that the overall reaction rate was increased by over 100% by applying a moderate alternating magnetic field (500 Hz, 17 Gs), or using additional spacers, both of which could improve the mobility of the immobilized catalysts. We further observed that integrated immobilization, which allowed the cofactor to be placed in the molecular vicinity of enzymes on the same nanoparticles, could enhance the reaction rate by 1.8 fold. These results demonstrated the feasibility in manipulating molecular interactions among immobilized catalyst components by using nanoscale fabrication for efficient multienzymic biosynthesis. (C) 2011 Elsevier B. V. All rights reserved

Temperature sensitivity of cellulase adsorption on lignin and its impact on enzymatic hydrolysis of lignocellulosic biomass

Unproductive enzyme adsorption is an important factor in addition to steric hindrance of lignin that limits the enzymatic hydrolysis of lignocellulosic biomass. While both are important factors, enzymatic hydrolysis of pretreated biomass is most likely conducted in the presence of certain amount of lignin residues that may not necessarily present accessibility hindrance, but can competitively absorb the enzyme. This paper presents a study with purified lignin samples to elucidate the role of unproductive enzyme adsorption. It appeared that lignin adsorbed cellulase quickly at 4 degrees C with adsorption equilibrium reached within 1 h, similar to that observed for crystalline cellulose. Increasing temperature to 50 degrees C (typical hydrolytic reaction condition) facilitated the rate of cellulase adsorption on cellulose with a peak of adsorption reached at 0.25 h; however, adsorption on lignin was surprisingly slower and took over 12 h to reach equilibrium, which was accompanied with a 10-fold increase in adsorption capacity. Despite the high adsorption capacity of lignin (which is comparable to that of cellulose) at 50 degrees C, the presence of added lignin imposed only minimal impact on the enzyme apparent activity, most likely due to the slow adsorption kinetics of lignin. (c) 2013 The Authors. Published by Elsevier B.V. All rights reserved