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Purification and Characterization of a Novel Thermostable Chitinase from Thermomyces lanuginosus SY2 and Cloning of Its Encoding Gene

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Agricultural Sciences in China 2008年第12期7卷 1458-1465页

作者： GUO Run-fang SHI Bao-sheng LI Duo-chua MA Wen WEI Qing Department of Bioengineering Agricultural University of Hebei Baoding 071000 P.R.China Department of Environmental Biology Shandong Agricultural University Tai＇an 271018 P.R.China

A novel thermostable extracellular chitinase was purified from the culture filtrate of Thermomyces lanuginosus SY2 by using diethylaminoethyl Sepharose chromatography and Phenyl-Sepharose chromatography. The molecular size of the purified chitinase was estimated to be 48 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The chitinase exhibited optimum catalytic activity at pH 4.5 and 55℃. The enzyme was stable at 50℃, and its half-life time at 65℃ was 25 rain. The thermostable chitinase was obtained with 60% of the full activity, when it was incubated in the buffer （pH 2.5）. The enzyme showed the unique properties for thermostability and pH stability since it was one of the most thermostable chitinases so far isolated in fungi. Ca^2＋, Ba^2＋, Na^＋, and K^＋ enhanced the enzyme activity, whereas Fe^2＋, Ag^＋, Hg^2＋, and ethylene diamine tetraacetic acid caused obvious inhibition. The N-terminal amino acids were AQGYLSVQYFVNWAI. Degenerate primers based on the N-terminal sequences of purified chitinase and a cDNA fragment encoding the chitinase gene were obtained through reverse transcriptase-polymerase chain reaction amplication. The RACE was used to generate full-length cDNA clones. The cDNA of chit contained an open reading frame of 1 326 bp encoding 442 amino acids. The gene chit has been registered in GenBank with accession number DQ092332. The alignment results of putative amino acid sequence showed the lower similarity to other chitinases in family-18 except for the catalytic domain containing two conserved motifs related with catalytic activity of chitinase.

关键词： Thermomyces lanuginosus SY2 thermostable chitinase purification cDNA cloning

Genetic diversity of the S-type small subunit ribosomal RNA gene of Plasmodium knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia

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Asian Pacific Journal of Tropical Medicine 2024年第2期17卷 84-90页

作者： Eric Tzyy Jiann Chong Joveen Wan Fen Neoh Tiek Ying Lau Kek Heng chua Yvonne Ai-Lian Lim Ping-Chin Lee Biotechnology Research Institute Universiti Malaysia SabahJalan UMS88400 Kota KinabaluSabahMalaysia Department of Biomedical Science Faculty of Medicine BuildingUniversity of Malaya50603 Kuala LumpurMalaysia Centre of Excellence for Research in AIDS(CERiA) University of Malaya50603 Kuala LumpurMalaysia Faculty of Science and Natural Resources Universiti Malaysia SabahJalan UMS88400 Kota KinabaluSabahMalaysia

Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and ***:Thirty-nine blood samples infected with *** were collected in Sabah,Malaysian Borneo and Peninsular *** S-type SSU rRNA gene was amplified using polymerase chain reaction,cloned into a vector,and *** natural selection and haplotype of the S-type SSU rRNA gene sequences were determined using DnaSP v6 and illustrated using NETWORK *** study's 39 S-type SSU rRNA sequences and eight sequences from the Genbank database were subjected to phylogenetic analysis using MEGA ***:Overall,the phylogenetic analysis showed no evidence of a geographical cluster of *** isolates from different areas in Malaysia based on the S-type SSU rRNA gene *** S-type SSU rRNA gene sequences were relatively conserved and with a purifying *** sharing of the S-type SSU rRNA gene was observed between the *** isolates in Sabah,Malaysian Borneo,but not between Sabah,Malaysian Borneo and Peninsular ***:This study suggests that the S-type SSU rRNA gene of *** isolates in Sabah,Malaysian Borneo,and Peninsular Malaysia has fewer polymorphic sites,representing the conservation of the *** features make the S-type SSU rRNA gene suitable for comparative studies,such as determining the evolutionary relationships and common ancestry among *** species.

关键词： Plasmodium knowlesi S-type small subunit ribosomal RNA Genetic diversity Natural selection Haplotype

A bi-level optimization for a make-to-order manufacturing supply chain planning:a case in the steel industry Lanndon

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Journal of Management Analytics 2021年第4期8卷 598-621页

作者： Lanndon A.Ocampo Neelesh N.Vasnani Felixter Leone S.chua Lance Brandon M.Pacio Brian J.Galli Department of Industrial Engineering Cebu Technological UniversityCebu CityPhilippines Graduate School Cebu Technological UniversityCebu CityPhilippines Department of Industrial Engineering University of San CarlosCebu CityPhilippines School of Computer Science Innovation&Management EngineeringHofstra UniversityHempsteadNew YorkUSA

This paper presents an actual case application of a newly developed gametheoretic model in analyzing a single manufacturer-many supplier,multi-period,make-to-order supply chain with fuzzy *** supply chain under consideration comprises an exclusive supplier for every component required by the manufacturer in producing its *** certain instances,some supply chains enable the manufacturer to opt for a third-party subcontractor to produce a portion of its *** assume that the supply chain faces a price and lead-time-sensitive demand,which is relevant in a make-to-order *** vertical interaction within the supply chain is played as a Stackelberg game,where the manufacturer is considered the leader and the suppliers as the *** show some important managerial insights in supply chain planning under a make-to-order condition.

关键词： Make-to-order supply chain production planning Stackelberg game bi-level optimization

Improvement of Information Flow in the Construction Supply chain

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Improvement of Information Flow in the Construction Supply C...

作者： Veronica Charmaine chua 华北电力大学(北京)

学位级别：硕士

In automotive and manufacturing industries, Lean principle has been widely recognized and adopted with the main purpose of improving supply chain management and performance through waste reduction. Nowadays, it is applied in the construction industry as a means to improve its overall project supply chain and performance as well. However, various researches proved that merely physical waste reduction is no longer sufficient as efficient information flow is the key and lifeblood to the success in this information technology digital era. This opens up an idea that for a construction company to be competitive enough, it depends on the adoption and effective application of digitalization in construction supply chain in terms of information flow. The main objective of this paper is to achieve lean construction supply chain through digitalization of construction supply chain’s information flow. In order to achieve this, the process requires real-time information sharing among all the participants from centralized information source of the supply chain, thus, the author aims to present a theoretical digitalization process of the information flow on general contractor’s level in lieu with this idea. The digitalization of information flow is critically essential to the enhancement of the current supply chain network of the construction. When there is an increase in the effectiveness and accuracy of information transfer involved in the construction information supply chain, various costs due to errors, delays and rework are greatly reduced through the digitalization. In order to become knowledgeable of typical work process in the supply chain and to choose the appropriate value stream or process for the completion of the work models for the paper, the author conducts an on-site semi-structured interview in a building construction site in the Philippines, which serves as the case study. In addition to that, value stream mapping （VSM） is used to outline the processes, to simplif

关键词： Lean Digitalization Construction Supply chain Information Flow Value Stream Mapping

A robust,integrated platform for comprehensive analyses of acylcoenzyme As and acyl-carnitines revealed chain length-dependent disparity in fatty acyl metabolic fates across Drosophila development

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Science Bulletin 2020年第21期65卷 1840-1848,M0004页

作者： Sin Man Lam Tianxing Zhou Jie Li Shaohua Zhang Gek Huey chua Bowen Li Guanghou Shui State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China LipidALL Technologies Company Limited Changzhou 213022China University of Chinese Academy of Sciences Beijing 100049China

Acyl-coenzyme A thioesters(acyl-CoAs)denote a key class of intermediary metabolites that lies at the hub of major metabolic *** great diversity in polarity between short-and long-chain acylCoAs makes it technically challenging to cover an inclusive range of acyl-CoAs within a single *** of acyl-carnitines,which function to convey fatty acyls into mitochondria matrix forβ-oxidation,indicate the efficiency of mitochondrial import and utilization of corresponding ***,we report a robust,integrated platform to allow simultaneous quantitation of endogenous acyl-CoAs and *** this method,we monitored changes in intermediary lipid profiles across Drosophila development under control(ND)and high-fat diet(HFD).We observed specific accumulations of medium-chain(C8-C12)and long-chain(≥C16)acyl-carnitines distinct to L3 larval and pupal stages,*** observations suggested development-specific,chain length-dependent disparity in metabolic fates of acyl-CoAs across Drosophila development,which was validated by deploying the same platform to monitor isotope incorporation introduced from labelled 12:0 and 16:0 fatty acids into extra-and intra-mitochondrial acyl-CoA *** found that pupal mitochondria preferentially import and oxidise C12:0-CoAs(accumulated as C12:0-carnitines in L3 stage)over C16:*** oxidation of medium-chain acyl-CoAs limits mitochondrial utilization of long-chain acyl-CoAs(C16-C18),leading to pupal-specific accumulation of long-chain acyl-carnitines mediated by enhanced CPT1-6 A *** skewed C16:0-CoAs towards catabolism over anabolism in pupa,thereby adversely affecting overall *** developed platform emphasizes the importance of integrating biological knowledge in the design of pathway-oriented platforms to derive maximal physiological insights from analysis of complex biological systems.

关键词： Acyl-coenzyme As Acyl-carnitines Fatty acids Drosophila High-fat diet β-Oxidation

Modelling and Analysis of TCP Performance in Wireless Multihop Networks

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Wireless Sensor Network 2010年第7期2卷 493-503页

作者： Hannan Xiao Ying Zhang James Malcolm Bruce Christianson Kee chaing chua 不详

Researchers have used extensive simulation and experimental studies to understand TCP performance in wireless multihop networks. In contrast, the objective of this paper is to theoretically analyze TCP performance in this environment. By examining the case of running one TCP session over a string topology, a system model for analyzing TCP performance in multihop wireless networks is proposed, which considers packet buffering, contention of nodes for access to the wireless channel, and spatial reuse of the wireless channel. Markov chain modelling is applied to analyze this system model. Analytical results show that when the number of hops that the TCP session crosses is ?xed, the TCP throughput is independent of the TCP congestion window size. When the number of hops increases from one, the TCP throughput decreases ?rst, and then stabilizes when the number of hops becomes large. The analysis is validated by comparing the numerical and simulation results.

关键词： Wireless Multihop Networks TCP Modelling TCP Ad Hoc Networks

A comparison of the clinical, demographic and psychiatric profiles among patients with erosive and non-erosive reflux disease in a multi-ethnic Asian country

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World Journal of Gastroenterology 2005年第23期11卷 3558-3561页

作者： Tiing-Leong Ang Kwong-Ming Fock Tay-Meng Ng Eng-Kiong Teo Tju-Siang chua Jessica Tan Division of Gastroenterology

AIM:To examine the clinical spectrum of gastroesophageal reflux disease (GERD) and compare erosive (ERD) with non-erosive (NERD) in terms of clinical, demographic and psychiatric profiles. METHODS: Patients with reflux symptoms were enrolled and stratified to NERD and ERD after endoscopy (LA classification). Patients with ERD presenting with dyspepsia were included. Patients on proton pump inhibitors (PPI) or H2 receptor antagonists before endoscopy were excluded. Demographic data, Helicobacter pylori(H pylori) status and presence of minor psychiatric morbidity (based on General Health Questionnaire-28) were analyzed. RESULTS: Among 690 patients screened, 533 were eligible for analysis (male to female ratio: 3:2; Chinese: 75.4%; Malay: 9.8%; Indian: 14.8%). Clinical spectrum of GERD: N: 40.5%; A: 46%; B: 9.2%; C: 2.1%; D: 0.6%; Barrett's esophagus: 1.7%. Compared to patients with NERD, patients with ERD were significantly older (45 vs 39.4 years), more likely to be male (64.4% vs 53.7%), tended to smoke (19.6% vs 9.7%), less likely to have minor psychiatric morbidity (26.4 vs 46.7%) and were more likely to respond to PPI (79.7 vs 66.8%). There was also a trend towards a higher BMI (24.5 vs 23.5). Race, alcohol consumption and H pylori status were not significant. On multivariate analysis, age and presence of minor psychiatric morbidity remained with significant differences. CONCLUSION: The majority of patients who have typical symptoms of GERD have NERD or mild erosive reflux disease. Compared to patients with erosive reflux disease, patients with NERD were younger and had a higher prevalence of minor psychiatric morbidity.

关键词： Reflux disease Clinical spectrum Psychiatric morbidity

HSV-tk/GCV自杀基因治疗系统对人喉鳞状细胞癌细胞系的体外作用

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中华耳鼻咽喉头颈外科杂志 2006年第5期41卷 374-376页

作者：丁秀勇秦永李付英丛铁川北京大学第一临床医院耳鼻咽喉头颈外科北京大学医学部生物化学中心实验室

目的探讨HSV-tk/GCV(人类单纯疱疹病毒胸苷激酶联合更昔洛韦)自杀基因治疗系统对喉鳞状细胞癌细胞系Hep-2的体外作用。方法脂质体介导HSV-tk基因转染Hep-2细胞,逆转录聚合酶链反应(reverse transcription polymerase chain reaction,RT-... 详细信息

目的探讨HSV-tk/GCV(人类单纯疱疹病毒胸苷激酶联合更昔洛韦)自杀基因治疗系统对喉鳞状细胞癌细胞系Hep-2的体外作用。方法脂质体介导HSV-tk基因转染Hep-2细胞,逆转录聚合酶链反应(reverse transcription polymerase chain reaction,RT-PCR)检测HSV-tk基因的表达;四甲基偶氮唑蓝法检测该系统对Hep-2细胞的体外抑制作用,流式细胞仪检测细胞周期阻滞和凋亡现象。结果脂质体能介导HSV-tk基因转染Hep-2细胞;HSV-tk/GCV系统对Hep-2细胞具有生长抑制效应;更昔洛韦(ganciclovir,GCV)浓度为20μg/ml时其抑制率达到40%;HSV-tk/GCV自杀基因治疗系统主要通过S期细胞周期阻滞对Hep-2细胞发挥体外抑制作用,没有明显的细胞凋亡和坏死。结论HSV-tk/GCV系统主要通过细胞周期阻滞作用对Hep-2细胞发挥体外抑制作用。HSV-tk/GCV系统对Hep-2细胞是否具直接杀伤作用有待于进一步探讨。HSV-tk/GCV系统具有潜在临床应用价值。

关键词：喉肿瘤胸苷激酶基因疗法

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脂肪乳剂治疗急性胰腺炎的系统评价

中国循证医学杂志 2009年第4期9卷 452-457页

作者：肖青川吴泰相兑丹华兰天罡李杰惠遵义医学院附属医院肝胆胰外科遵义563003 四川大学华西医院中国循证医学中心成都610041

目的系统评价脂肪乳剂治疗急性胰腺炎(AP)的疗效和安全性。方法计算机检索Cochrane图书馆临床对照试验资料库(2007年第2期)、MEDLINE(1966～2007.4)、EMbas(e1984～2007.4)、CBM(1978～2007.4),手工检索及向药厂索取资料,全面收集世界... 详细信息

目的系统评价脂肪乳剂治疗急性胰腺炎(AP)的疗效和安全性。方法计算机检索Cochrane图书馆临床对照试验资料库(2007年第2期)、MEDLINE(1966～2007.4)、EMbas(e1984～2007.4)、CBM(1978～2007.4),手工检索及向药厂索取资料,全面收集世界范围内脂肪乳剂治疗急性胰腺炎的随机和半随机对照试验,并按Cochrane协作网推荐的方法进行系统评价。结果共纳入10个临床对照试验研究包括314例患者。结果显示,①长链脂肪乳剂不能改善AP病人病死率[RR=0.73,95%CI(0.34,1.58)],但可降低并发症发生率和缩短住院时间(均P>0.05);对血脂的影响尚无一致结论;②1个研究提示,中/长链脂肪乳剂不能明显增加治疗4天后及8天后AP患者血清甘油三脂和血清胆固醇水平(均P>0.05);③未发现脂肪乳剂有严重的不良反应。结论现有的临床研究表明,与对照组比较,长链脂肪乳剂不能改善AP患者病死率,应用脂肪乳剂可能安全。由于研究质量及研究样本的局限性,本系统评价证据强度有限,尚不足以全面评价脂肪乳剂的疗效和安全性。尚需高质量、大样本的随机对照试验予以进一步明确。

关键词：脂肪乳剂急性胰腺炎营养支持系统评价 Meta分析