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Enhanced refolding of lysozyme with imidazolium-based room temperature ionic liquids: Effect of hydrophobicity and sulfur residue

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Science China Chemistry 2012年第8期55卷 1657-1662页

作者： BAE Sang-Woo ChaNG Woo-Jin KOO Yoon-mo ha Sung Ho Department of Biological Engineering Inha University Incheon 402-751 Republic of Korea Department of mechanical Engineering School of Freshwater Sciences University of Wisconsin-Milwaukee Milwaukee WI 53201-0413 USA Department of Chemical Engineering and Nano-Bio Technology Hannam University Daejeon 305-811 Republic of Korea

The expression of recombinant proteins in microorganism frequently leads to the formation of insoluble aggregates, inclusion bodies （IBs）. Thus, the additional in vitro protein refolding process is required to convert inactive IBs into water-soluble active proteins. This study investigated the effect of sulfur residue and hydrophobicity of imidazolium-based room temperature ionic liquids （RTILs） on the refolding of lysozyme as a model protein in the batch dilution method which is the most commonly used refolding method. When lysozyme was refolded in the refolding buffer containing [BF4]-based RTILs with a systematic variety of alkyl chain on cations varying from two to eight, less hydrophobic imidazolium cations having shorter alkyl chains were effective to facilitate lysozyme refolding. Compared to the conventional refolding buffer, 2 times higher lysozyme re- folding yield was obtained in l-ethyl-3-methylimidazolium tetrafluoroborate （[EmIm][BF4]） containing refolding buffer. The refolding yield of lysozyme was even more increased by 2.5 times when 1-butyl-3-methylimidazolium methylsulfate （[BmIm][mS]） containing sulfur residue on anion was used. The sulfur residue in [BmIm][mS] is supposed to improve the refolding yield of lysozyme which has 4 intrarnolecular disulfide bonds. For dilution-based refolding of lysozyme, the opti- mum concentrations of RTILs in refolding buffer were found to be 1.0 m [EmIm][BF4] and 0.5 m [PmIm][mS], respectively. The optimum temperate for dilution-based refolding of lysozyme with RTILs was 4 ℃.

关键词： protein refolding room temperature ionic liquid dilution refolding lysozyme hydrophobicity sulfur

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Synthesis and mesomorphic behavior of benzothiazole-based liquid crystals having terminal methoxyl group

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Chinese Chemical Letters 2009年第12期20卷 1449-1452页

作者： Sie Tiong ha Teck ming Koh Siew Teng Ong Yasodha Sivasothy Department of Chemical Science Faculty of ScienceEngineering & TechnologyUniversiti Tunku Abdul RahmanJln UniversitiBandar Barat 31900 KamparPerakMalaysia Department of Science Faculty of Engineering & ScienceUniversiti Tunku Abdul RahmanJln Genting KlangSetapak 53300 Kuala LumpurMalaysia Chemistry Department Faculty of ScienceUniversiti Malaya 50603 Kuala LumpurMalaysia

A homologous series of benzothiazole derivatives, 6-methoxy-2-（4-alkanoyloxybenzylidenamino）benzothiazoles, were synthesized and characterized using FT-IR, ^1H and ^13C NmR, mass spectrometry and elemental analysis. Enantiotropic nematic phase was observed throughout the entire series. Smectic C phase only emerged from the decanoyloxy derivative onwards. The terminal methoxyl group and the ester linkage influenced the mesomorphic behavior of the present series.

关键词： Benzothiazole Schiff bases Nematic Smectic C Liquid crystal

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Transparent conducting materials discovery using high-throughput computing

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npj Computational materials 2019年第1期5卷 606-618页

作者： Guillaume Brunin Francesco Ricci Viet-Anh ha Gian-marco Rignanese Geoffroy hautier UCLouvain Institut de la Matière Condensée et des Nanosciences(IMCN)Chemin desÉtoiles 8Louvain-la-Neuve 1348Belgium

Transparent conducting materials(TCms)are required in many applications from solar cells to transparent *** high performance materials combining the antagonistic properties of transparency and conductivity has been challenging especially for p-type ***,high-throughput ab initio computational screening has emerged as a formidable tool for accelerating materials *** this review,we discuss how this approach has been applied for identifying *** provide a brief overview of the different materials properties of importance for TCms(e.g.,dopability,effective mass,and transparency)and present the ab initio techniques available to assess *** focus on the accuracy of the methodologies as well as their suitability for high-throughput ***,we review the different high-throughput computational studies searching for new TCms and discuss their differences in terms of methodologies and main findings.

关键词： transparency conducting suitability

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Ethyl acetate extract of Smilax glabra Roxb roots and its major active compound astilbin promote osteoblastogenesis in vitro by upregulating bone cell differentiation-associated genes

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Asian Pacific Journal of Tropical Biomedicine 2021年第12期11卷 553-560页

作者： Huyen T.T.Nguyen minh T.H.Nguyen Thu X.Nguyen Quan m.Pham ha X.Nguyen Phuong T.m.Nguyen University of Science and Technology of hanoi Vietnam Academy of Science and TechnologyHanoiVietnam Institute of Biotechnology Vietnam Academy of Science and TechnologyHanoiVietnam Institute of Natural Products Chemistry Vietnam Academy of Science and TechnologyHanoiVietnam Graduate University of Science and Technology Vietnam Academy of Science and TechnologyHanoiVietnam

Objective:To investigate the osteoblastogenic activity of the ethyl acetate(EtOAc)extract of Smilax glabra Roxb roots and its major active compound ***:Astilbin was isolated from EtOAc extract using silica gel chromatography combined with fraction *** structure of astilbin was determined by analysis of the spectroscopic data in comparison with the *** method was used to detect the *** phosphatase(ALP)activity was determined by the spectrophotometric method at 405 nm using p-nitrophenyl phosphate as a *** deposition was stained with alizarin red-S,distained with cetylpyridium chloride,and quantified at 562 *** silico model for astilbin-ALP interaction was analyzed using AutoDock *** changes in expression of osteoblast differentiation related genes were determined using quantitative real-time ***:Both the EtOAc extract and astilbin had no toxicity toward osteoblast mC3T3-E1 cells at 5.0,10,25,and 50μg/*** 25μg/mL,they enhanced ALP activity and mineralization of osteoblasts up to 30%and 55%for the EtOAc extract and 22%and 41%for astilbin,*** docking analysis of astilbin-ALP interaction revealed Arg167,Asp320,His324,and His437 were key residues participating in hydrophobic interaction;meanwhile,His434 and Thr436 residues were involved in hydrogen bond formation in the active site of human tissue-nonspecific ***,the expression level of genes opn,col1,osx,and runx2 were up-regulated in astilbin treated samples with the fold changes as 2.2;3.7;4.1;2.3,respectively at 10μg/mL(Pmajor compound astilbin exhibit osteoblastogenic activity by up-regulating important markers for bone cell *** could be a new and promising osteogenic agent with dual actions for therapeutic applications.

关键词： Smilax glabra Roxb Astilbin Cytotoxicity Osteogenesis Osteoblast Ethyl acetate extract

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Design of 512-bit logic process-based single poly EEPROm IP

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Journal of Central South University 2011年第6期18卷 2036-2044页

作者：金丽妍 JANG Ji-Hye 余忆宁 ha Pan-Bong KIm Young-Hee Department of Electronic Engineering Changwon National University

A single poly EEPROm cell circuit sharing the deep N-well of a cell array was designed using the logic process. The proposed cell is written by the FN tunneling scheme and the cell size is 41.26 μm2, about 37% smaller than the conventional cell. Also, a small-area and low-power 512-bit EEPROm IP was designed using the proposed cells which was used for a 900 mHz passive UHF RFID tag chip. To secure the operation of the cell proposed with 3.3 V devices and the reliability of the used devices, an EEPROm core circuit and a DC-DC converter were proposed. Simulation results for the designed EEPROm IP based on the 0.18μm logic process show that the power consumptions in read mode, program mode and erase mode are 11.82, 25.15, and 24.08 ~tW, respectively, and the EEPROm size is 0.12 mm2.

关键词： single poly EEPROm cell Fowler-Nordheim tunneling logic process radio frequency identification small area

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Biocompatibility evaluation in vitro. Part I: morphology expression and proliferation of human and rat osteoblasts on the biomaterials

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Journal of Central South University of Technology 2001年第1期8卷 1-8页

作者： RUAN Jian ming 1,GRANT m. Helen 2 (1 Powder metallurgy State Key Laboratory, Central South University, Changsha 410083, China 2 Bioengineering Unit, Strathclyde University, Glasgow, G4 0NW, UK) Powder metallurgy State Key Laboratory Central South University Changsha China Bioengineering Unit Strathclyde University Glasgow UK

The biocompatibility evaluation of calcium phosphate based biomaterials is performed by tissue culture in vitro model. Three kinds of bioceramic materials which are potential to deal with bone trauma and/or conduct tissue growth are recommodated. The biological research results show that human and animal osteoblast cells anchor the materials surface in two hours in culture. Confocal laser scanning microscopy (CLSm) demonstrated the normal cell distribution and proliferation on both of dense and porous biomaterials. Hydroxyapatite and tricalcium phosphate stimulate cell proliferation. However, DNA and protein synthesis were considerably limited and the apoptosis phenomenon would be present on the hydroxyapatite (ha) materials by adding Al, mg elements. Several important methods of biocompatibility evaluation of implant materials are described and the related biological molecular techniques such as tissue culture, cell transfection, cellular DNA stain, and Lowry assay are involved in the present research.

关键词： biomaterials tissue culture cell morphology proliferation

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Inner Co Synergizing Outer Ru Supported on Carbon Nanotubes for Efficient pH-Universal Hydrogen Evolution Catalysis

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Nano-micro Letters 2022年第11期14卷 275-289页

作者： Jian Chen Yuan ha Ruirui Wang Yanxia Liu Hongbin Xu Bin Shang Renbing Wu Hongge Pan Institute of Science and Technology for New Energy Xi’an Technological UniversityXi’an 710021People’s Republic of China School of Advanced materials and Nanotechnology Xidian UniversityXi’an 710126People’s Republic of China Department of materials Science Fudan UniversityShanghai 200433People’s Republic of China State Key Laboratory of New Textile materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430073People’s Republic of China State Key Laboratory of Silicon materials and School of materials Science and Engineering Zhejiang UniversityHangzhou 310027People’s Republic of China

Exploring highly active but inexpensive electrocatalysts for the hydrogen evolution reaction(HER)is of critical importance for hydrogen production from electrochemical water ***,we report a multicomponent catalyst with exceptional activity and durability for HER,in which cobalt nanoparticles were in-situ confined inside bamboo-like carbon nanotubes(CNTs)while ultralow ruthenium loading(~2.6μg per electrode area~cm^(−2))is uniformly deposited on their exterior walls(Co@CNTsǀRu).The atomic-scale structural investigations and theoretical calculations indicate that the confined inner Co and loaded outer Ru would induce charge redistribution and a synergistic electron coupling,not only optimizing the adsorption energy of H intermediates(ΔGH*)but also facilitating the electron/mass *** as-developed Co@CNTsǀRu composite catalyst requires overpotentials of only 10,32,and 63 mV to afford a current density of 10 mA cm^(−2) in alkaline,acidic and neutral media,respectively,representing top-level catalytic activity among all reported HER *** current work may open a new insight into the rational design of carbon-supported metal catalysts for practical applications.

关键词： Cobalt nanoparticles Carbon nanotubes Ru nanoclusters Hydrogen evolution reaction

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Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

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Forest Ecosystems 2024年第1期11卷 14-23页

作者： Sisira Ediriweera Champika Bandara Tithira Lakkana Shanika Jayasinghe David Woodbury Arun Dayanandan B.m.P.Singhakumara Xiangcheng mi I.A.U.N.Gunatilleke C.V.S.Gunatilleke mark SAshton Department of Science and Technology Uva Wellassa UniversityBadullaSri Lanka The Forest School Yale School of the EnvironmentYale UniversityNew HavenCT06511USA Department of Forestry and Environmental Science University of Sri JayewardenepuraNugegodaSri Lanka State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China Botany Department University of PeradeniyaPeradeniyaSri Lanka

Background:No studies have documented long-term trends in aboveground biomass(AGB)for mixed-dipterocarp forests(mDF),the dominant rain forest type in tropical wet equatorial *** our study,we sought to document such trends over forty years across three sites representing lowland to lower montane ***:To do this,we established fifty 100 m×25 m plots in 1978 across three sites sampled along an elevation gradient,identified as mature old-growth *** measured trees for diameter at breast height that we identified to species and *** took wood samples to calculate species wood-specific *** re-measured plots in 1998 and again in ***:We show standing AGB for all sites combined to be 517.52 mg·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 mg·ha^(-1).No differences exist among sites in AGB primarily because of considerable within site variation;but interactions of time with site show declines across sites were not uniform,one remained about the *** few species represented a high proportion of the AGB with the top five species comprising between 34%and 65%,depending upon site and year *** species,mesua nagassarium,represented a disproportionately large amount of AGB and decline over time,particularly at the low elevation ***:Our results are directly relevant to estimating AGB and standing carbon sequestered in *** study is the first to demonstrate varying but overall,declining trends in amounts of AGB among forests making predictions of biomass and standing carbon in mDF difficult over wide regions.

关键词： Western ghats Shorea spp. Southeast Asia Sri Lanka Tropical rain forest Wood specific gravity

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可再生高强度纤维素基包装材料制备及其智能化应用

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中国造纸 2024年第7期43卷 149-159页

作者：王笑刘哈王月莹赵玉李新才王宝斌杨桂花陈嘉川齐鲁工业大学(山东省科学院)生物基材料与绿色造纸国家重点实验室山东济南250353

本研究提出了一种高强度可降解纤维素基复合打包带替代传统聚乙烯打包带的可靠策略,采用离子液体溶解制备再生纤维素材料,探讨了石墨烯对其导电性和机械性能的影响,从而制备高强度新型可再生复合打包带,并初步探索了其在智能包装领域的... 详细信息

本研究提出了一种高强度可降解纤维素基复合打包带替代传统聚乙烯打包带的可靠策略,采用离子液体溶解制备再生纤维素材料,探讨了石墨烯对其导电性和机械性能的影响,从而制备高强度新型可再生复合打包带,并初步探索了其在智能包装领域的应用前景。结果表明,纤维素含量5%时,制得的再生纤维素丝和再生纤维素膜的拉伸强度分别可达194和74 kPa;双层打包带的最大应力可达26.3 mPa;再生纤维素打包带对于环境湿度和压力变化响应灵敏且具有良好的抗水性和生物降解性;纤维素和石墨烯质量比为1∶1时,纤维素/石墨烯复合材料电导率达0.8 S/m。

关键词：离子液体再生纤维素智能包装石墨烯

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Influence of anodization conditions on deposition of Hydroxyapatite on α/β Ti alloys for Osseointegration: Atomic Force microscopy Analysis

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Transactions of Nonferrous metals Society of China 2024年

作者： Rania E.hammam Engie m.Safwat Soha A.Abdel-Gawad madiha Shoeib Shimaa El-hadad Faculty of Engineering， modern University for Technology and Information (mTI) Restorative and Dental materials Department， National Research Centre Giza Chemistry Department， Faculty of Science， Cairo University Central metallurgical Research and Development Institute P.O.87

Integrating titanium-based implants with the surrounding bone tissue remains challenging. This study aims to explore the impact of different anodization voltages （20-80V） on the surface topography of two-phase （α/β） Ti alloys and to produce TiO2films with enhanced bone formation abilities. Scanning electron microscopy coupled with energy dispersive spectroscopy （SEm-EDS） and atomic force microscopy （AFm） were applied to investigate the morphological， chemical， and surface topography of the prepared alloys and to confirm the growth of hydroxyapatite （ha） on their surfaces. Results disclosed that the surface roughness of TiO2films formed on Ti-6Al-7Nb alloys was superior to that of Ti–6Al–4V alloys. Ti-6Al-7Nb alloy anodized at 80 V had the highest yields of ha after immersion in SBF with enhanced ha surface coverage. The developed ha layer had a mean thickness of 128.38 ± 18.13 μm， suggesting its potential use as an orthopedic implantable material due to its promising bone integration and， hence， remarkable stability inside the human body.

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