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Cloning of a novel phytase from an anaerobic rumen bacterium, Mitsuokella jalaludinii, and its expression in Escherichia coli

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Journal of Integrative Agriculture 2015年第9期14卷 1816-1826页

作者： TAN Wan-qin Phang Chiun Yee Sieo chin chin Yiap Beow chin Clemente Michael Wong Vui Ling Norhani Abdullah Son Radu Ho Yin Wan Laboratory of Vaccines and Immunotherapeutics Institute of BioscienceUniversiti Putra Malaysia Department of Microbiology Faculty of Biotechnology and Biomolecular SciencesUniversiti Putra Malaysia Department of Life Sciences School of Pharmacy and HealthFaculty of Medicine and HealthInternational Medical University Biotechnology Research Institute Universiti Malaysia Sabah Institute of Tropical Agriculture Universiti Putra Malaysia Department of Biochemistry Faculty of Biotechnology and Biomolecular SciencesUniversiti Putra Malaysia Department of Food Science Faculty of Food Science and TechnologyUniversiti Putra Malaysia

The ful length phytase gene of Mitsuokel a jalaludini was successful y cloned and was found to be 1 047 bp in length, with 348 amino acids, and was designated as PHY7 phytase gene. A comparison of the sequence of PHY7 phytase gene of M. jalaludini with various microbial phytase gene sequences showed that it was not similar to those from other bacteria except Selenomonas ruminatium, thus suggesting that they may both express a new class of phytase. The PHY7 phytase gene was subsequently subcloned into bacterial expression vector, pET32a, for expression in Escherichia coli strain Ro-setta-gami. Expression of the recombinant phytase gene was optimised and characterised. The recombinant phytase was estimated to be approximately 55 kDa by SDS-PAGE analysis. The recombinant phytase exhibited optimum activity at 55°C, pH 4.5 and showed good pH stability from pH 3.5 to 5.5 (>78%relative activity). Metal ions such as Ca2+, Mg2+, and K+were found to exert signiifcant stimulatory effect on the recombinant phytase activity while Cu2+, Fe3+, and Zn2+greatly inhibited the enzyme activity. The recombinant phytase showed moderate resistance to trypsin proteolysis, but susceptible to pepsin proteolysis. The results of the study showed that several characteristics of recombinant phytase were slightly different from the native enzyme. Unfavourable characteristics such as reduced pH stability and metal ion effects should be taken into consideration during feed enzyme formulation.

关键词： phytase cloning recombinant Escherichia coli Mitsuokella jalaludinii

Ubiquitin phosphorylation in Parkinson’s disease:Implications for pathogenesis and treatment

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Translational Neurodegeneration 2016年第1期5卷 1-8页

作者： Lih-Shen chin Lian Li Department of Pharmacology and Center for Neurodegenerative Disease Emory University School of MedicineAtlantaGA 30322USA

Parkinson’s disease(PD)is the most common neurodegenerative movement disorder,characterized primarily by the loss of dopaminergic neurons in substantia *** pathogenic mechanisms of PD remain unclear,and no effective therapy currently exists to stop neurodegeneration in this debilitating *** identification of mutations in mitochondrial serine/threonine kinase PINK1 or E3 ubiquitin-protein ligase parkin as the cause of autosomal recessive PD opens up new avenues for uncovering neuroprotective pathways and PD pathogenic *** studies reveal that PINK1 translocates to the outer mitochondrial membrane in response to mitochondrial depolarization and phosphorylates ubiquitin at the residue *** phosphorylated ubiquitin serves as a signal for activating parkin and recruiting autophagy receptors to promote clearance of damaged mitochondria via *** evidence has begun to indicate a link between impaired ubiquitin phosphorylation-dependent mitophagy and PD pathogenesis and supports the potential of Ser65-phosphorylated ubiquitin as a biomarker for *** new mechanistic insights and phenotypic screens have identified multiple potential therapeutic targets for PD drug *** review highlights recent advances in understanding ubiquitin phosphorylation in mitochondrial quality control and PD pathogenesis and discusses how these findings can be translated into novel approaches for PD diagnostic and therapeutic development.

关键词： Mitophagy Parkinson’s disease PINK1 Parkin Ubiquitin-protein ligase Ubiquitin phosphorylation Mitochondrial quality control Mitophagy

Reaction Mechanism and Product Branching Ratios of OH+C2H3F Reaction:A Theoretical Study

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chinese Journal of Chemical Physics 2020年第2期33卷 203-209,I0003页

作者： Chih-Hao chin Tong Zhu John Zeng-Hui Zhang School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200062China NYU-ECNU Center for Computational Chemistry at NYU Shanghai Shanghai 200062China Department of Chemistry New York UniversityNew York 10003United States of America

Ab initio CCSD(T)/CBS//B3LYP/6-311G(d,p)calculations of the potential energy surface for possible dissociation channels of HOC2H3F,as well as Rice-Ramsperger-Kassel-Marcus(RRKM)calculations of rate constants,were carried out,in order to predict statistical product branching ratios in dissociation of HOC2H3F at various internal *** most favorable reaction pathway leading to the major CH2CHO+HF products is as the following:OH+C2H3F→i2→TS14→i6→TS9→i3→TS3→CH2CHO+HF,where the rate-determining step is HF elimination from the CO bridging position via TS11,lying above the reactants by 3.8 kcal/*** CH2O+CH2F products can be formed by F atom migration from Cαto Cβposition via TS14,then H migration from O to Cαposition via TS16,and C-C breaking to form the products via TS5,which is 1.8 kcal/mol lower in energy than the reactants,and 4.0 kcal/mol lower than TS11.

关键词： Ab initio Potential energy surface Reaction mechanism Rice-Ramsperger-Kassel-Marcus Branching ratio

T4-like coliphage ΦKAZ14 virulent to pathogenic and extended spectrum β-lactamase-producing Escherichia coli of poultry origin

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Virologica Sinica 2015年第1期30卷 73-75页

作者： Kaikabo Adamu Ahmad Abdulkarim Sabo Mohanmmed Faridah Abas Sieo chin chin Department of Food Science Faculty of Food Science and Technology Universitiy Putra Malaysia Bacterial Research Department National Veterinary Research Institute Department of Microbiology Faculty of Biotechnology and Biomolecular Sciences Universitiy Putra Malaysia

Dear Editor,Bacteriophages(otherwise called phages)are a type of virus that infect *** viral type has found useful applications in the control of bacterial pathogens in foods and food processing *** addition,phages ma... 详细信息

关键词： producing pathogenic lactamase ESBL otherwise environments phage chicken poultry avian

The rapid determination of volatile fatty acid number in para rubber latex using fourier transform-near infrared spectroscopy based on quantification and discrimination model

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Journal of Innovative Optical Health Sciences 2015年第5期8卷 107-115页

作者： Sureeporn Narongwongwattana Ronnarit Rittiron chin Hock Lim Department of Food Engineering Faculty of Engineering at Kamphaengsaen Kasetsart University NakhonpathomThailand Thai Rubber Latex Corporation(Thailand)Public Company Limited ChonburiThailand

Volatile Fatty Acid number(VFA no.)is one of the parameters indicating the state of quality of Para rubber latex at that particular *** factories analyze this parameter using standard analytical method as in ISO 506:1992(E).Nevertheless,this procedure is complicated,chemical and time consuming,as well as skilled analyst ***,near infrared(NIR)spectroscopy which is rapid,accurate and nonchemicals method was applied to determine the VFA *** latex and concentrated latex based on quantification and discriminant *** best calibration equation was obtained from standard normal variate(SNV)spectra in the region of 6109.7–5770.3,4613.1–4242.9 cm^(-1) with R?0:832,SECV?0:036 and no *** the performance check,statistically it was found that SECV and bias were low enough for practical acceptance and the predicted VFA *** not di®erent significantly from actual VFA *** 95% confidence *** addition,discriminant model was developed to separate good quality latex from the deteriorated latex using VFA *** 0.06 as standard as in ISO 2004:2010(E).The discriminant model can be used to screen the latex with overall accuracy of 91.86%in validation set.

关键词： Hevea brasiliensis latex quality polyisoprene ISO 12099:2010(E)

Functionalized activated carbon for the adsorptive removal of perchlorate from water solutions

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Frontiers of Chemical Science and Engineering 2015年第2期9卷 194-208页

作者： Rovshan MAHMUDOV chinglung CHEN chin-Pao HUANG Department of Civil and Environmental Engineering University of Delaware Newark DE 19716 USA

Two types of activated carbon, namely, Filtrasorb 400 and Nuchar SA, were functionalized by quaternary ammonium salts （quats）, as to enhance perchlorate adsorption. Results showed that the adsorption of quats on Nuchar SA increased with increase in chain length （hydrophobicity） of quats. Filtrasorb 400, however, had limited uptake of long-chain quats such as dodecyl- trimethylammonium and hexadecyltrimethylammoium （HDTMA）. Results indicated that perchlorate removal by the functionalized activated carbon was directly related to the chain length of the modifying quats. Perchlorate removal by functionalized activated carbon increased with increase in chain length of the modifying quats and became less pH-dependent. Modified Nuchar SA had higher overall perchlorate removal capacity than the modified Filtrasorb F400, but was more strongly affected by pH than Filtrasorb 400. Activated carbon treated with HDTMA exhibited the best perchlorate removal capacity among all quats studied. Results indicated that tailoring the activated carbon surface with HDTMA rendered the activated carbon surface positively charged, which resulted in substantial increase in perchlorate removal compared to unfunctionalized activated carbons.

关键词： perchlorate activated carbon removal func-tionalization quatemary ammonium salts

Neutral Dissociation of Superexcited Nitric Oxide Induced by Intense Laser Fields

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chinese Journal of Chemical Physics 2010年第3期23卷 252-254,I0001页

作者：刘凯宋迪 Ali Azarm See-Leang chin 孔繁敖北京分子科学国家实验室中国科学院化学研究所分子动态与稳态结构国家重点实验室北京100190 拉瓦尔大学魁北克GIK7P4

Superexcited states of NO molecule and their neutral dissociation processes have been studied both experimentally and theoretically. Neutral excited N^＊ and O^＊ atoms are detected by fluorescence spectroscopy for the NO molecule upon interaction with 800 nm intense laser radiation of duration 60 fs and intensity 0.2 PW/cm^2. Intense laser pulse causes neutral dissociation of superexcited NO molecule by way of multiphoton excitation, which is equivalent to single photon excitation in the extreme-ultraviolet region by synchrotron radiation. Potential energy curves （PECs） are also built using the calculated superexcited state of NO^＋. In light of the PECs, direct dissociation and pre-dissociation mechanisms are proposed respectively for the neutral dissociation leading to excited fragments N^＊ and O^＊.

关键词： Superexcited state Neutral dissociation Intense laser

Pollutant emission characteristics of rice husk combustion in a vortexing fluidized bed incinerator

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Journal of Environmental Sciences 2013年第2期25卷 335-339页

作者： Feng Duan Chiensong Chyang Yucheng chin Jim Tso School of Metallurgy and Resource Anhui University of Technology Department of Chemical Engineering Chung Yuan Christian University R&D Center for Environmental Technology Chung Yuan Christian University

Rice husk with high volatile content was burned in a pilot scale vortexing fluidized bed incinerator. The fluidized bed incinerator was constructed of 6 mm stainless steel with 0.45 m in diameter and 5 m in height. The emission characteristics of CO, NO, and SO2 were studied. The effects of operating parameters, such as primary air flow rate, secondary air flow rate, and excess air ratio on the pollutant emissions were also investigated. The results show that a large proportion of combustion occurs at the bed surface and the freeboard zone. The SO2 concentration in the flue gas decreases with increasing excess air ratio, while the NOx concentration shows reverse trend. The flow rate of secondary air has a significant impact on the CO emission. For a fixed primary air flowrate, CO emission decreases with the secondary air flowrate. For a fixed excess air ratio, CO emission decreases with the ratio of secondary to primary air flow. The minimum CO emission of 72 ppm is attained at the operating condition of 40% excess air ratio and 0.6 partition air ratio. The NOx and SO2 concentrations in the flue gas at this condition are 159 and 36 ppm, which conform to the EPA regulation of Taiwan.

关键词： incineration rice husk vortexing fluidized bed pollutant emission

Robust topology optimization of multi-material lattice structures under material and load uncertainties

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Frontiers of Mechanical Engineering 2019年第2期14卷 141-152页

作者： Yu-chin CHAN Kohei SHINTANI Wei CHEN Department of Mechanical Engineering Northwestern UniversityEvanstonIL 60208USA

Enabled by advancements in multi-material additive manufacturing,lightweight lattice structures consisting of networks of periodic unit cells have gained popularity due to their extraordinary performance and wide array of *** work proposes a density-based robust topology optimization method for meso-or macroscale multi-material lattice structures under any combination of material and load *** method utilizes a new generalized material interpolation scheme for an arbitrary number of materials,and employs univariate dimension reduction and Gauss-type quadrature to quantify and propagate *** formulating the objective function as a weighted sum of the mean and standard deviation of compliance,the tradeoff between optimality and robustness can be studied and *** of a cantilever beam lattice structure under various material and load uncertainty cases exhibit the efficiency and flexibility of the *** accuracy of univariate dimension reduction is validated by comparing the results to the Monte Carlo approach.

关键词： robust topology optimization lattice structures multi-material material uncertainty load uncertainty univariate dimension reduction