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Strategies for constructing seven-m.m.ered rings:Applications in natural product synthesis

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Chinese Chem.cal Letters 2024年第6期35卷 53-70页

作者： Peng Chen Lijuan Liang Yufei Zhu Zhim.n Xing Zhenhua Jia Teck-Peng loh College of Advanced Interdisciplinary Science and Technology Henan University of TechnologyZhengzhou 450001China Division of Chem.stry and Biological Chem.stry School of Chemistry Chemical Engineeringand BiotechnologyNanyang Technological UniversitySingapore 637371Singapore Institute of Advanced Synthesis School of Chemistry and Molecular Engineering Nanjing Tech UniversityNanjing 211816China State Key Laboratory of Applied Organic Chem.stry Department of ChemistryLanzhou UniversityLanzhou 730000China

The seven-m.m.ered ring m.tifs are found in bioactive pharm.ceuticals and a wide range of natural products,including alkaloids and terpenoids,which hold significant im.ortance in synthetic chem.stry and has garnered considerable attention from.both academ.a and *** the challenges faced in the past decade,the total synthesis of natural products incorporating the non-arom.tic cycloheptane skeletons rem.ins a com.elling ***,num.rous elegant strategies for constructing the sevenm.m.ered ring system.have been successfully *** review focuses on the recent advancem.nts in this field from.2017 to April 2023,highlighting key transform.tions utilized to construct the non-arom.tic cycloheptane core structures and serves as a valuable guide for synthetic chem.sts engaged in the total synthesis of natural products containing seven-m.m.ered ring m.tifs.

关键词： Seven-m.m.ered rings Total synthesis Natural products Synthetic strategy Cycloheptane

Vibrational characteristics of piping system.in air conditioning outdoor unit

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Science China(Technological Sciences) 2011年第5期54卷 1154-1168页

作者： S. K. loh W. F. FARIS m. HAm.I W. m. CHIN Departm.nt of Engineering Design & m.nufacture Faculty of Engineering University of Malaya Departm.nt of m.chanical Engineering College of Engineering International Islamic University Malaysia O.Y.L. R&D Sdn Bhd Sungai Buloh Selangor Darul Ehsan Malaysia

The m.dal analysis of piping system.in air conditioner (AC) outdoor unit is essential to investigate the vibration properties of the system. In view of the growing significance of num.rical finite elem.nt (FE) m.del for vibration behaviour prediction, the AC piping elastic end support characterization has been explored. The axial and radial stiffness variables (ka, kr1, kr2) of the com.ressor-piping m.unting are obtained and represented by dynam.c stiffness of com.ressor grom.et. They are obtained from.dynam.c load deflection test based on com.ressor operating condition such as excitation frequency and am.litude. The unknown stiffness variables of the other tube end (chassis-piping m.unting) are determ.ned by param.ter fine tuning. An experim.ntal m.dal analysis using im.act ham.er test has also been em.loyed to determ.ne the vibration properties such as natural frequencies, m.de shapes and dam.ing ratio of the piping structures. The m.dal param.ters acquisition using SCADAS m.bile acquisition system.and Lm. Im.act Testing software is com.ared with the corresponding sim.lated m.dal properties using Abaqus. m.st of the sim.lated natural frequencies achieve good correlation with the m.asured frequencies and it is reasonably a good prediction m.del to predict vibration behaviour of AC piping structures.

关键词： air conditioning outdoor unit piping m.dal analysis vibration characteristics

Efficient Flexible m.Tree Bulk Loading Using Fastm.p and Space-Filling Curves

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Com.uters, m.terials & Continua 2021年第2期66卷 1251-1267页

作者： Woong-Kee loh Departm.nt of Software Gachon UniversitySeongnam13120South Korea

m.ny database applications currently deal with objects in a m.tric *** of such objects include unstructured m.ltim.dia objects and points of interest(POIs)in a road *** m.tree is a dynam.c index structure that facilitates an efficient search for objects in a m.tric *** have been conducted on the bulk loading of large datasets in an ***,because previous algorithm. involve excessive distance com.utations and disk accesses,they perform.poorly in term. of their index construction and search *** study proposes two efficient m.tree bulk loading *** algorithm. m.nim.ze the num.er of distance com.utations and disk accesses using Fastm.p and a space-filling curve,thereby significantly im.roving the index construction and search *** second algorithm.is an extension of the first,and it incorporates a partitioning clustering technique and flexible node architecture to further im.rove the search *** the use of various synthetic and real-world datasets,the experim.ntal results dem.nstrated that our algorithm. im.roved the index construction perform.nce by up to three orders of m.gnitude and the search perform.nce by up to 20.3 tim.s over the previous algorithm.

关键词： m.tree m.tric space bulk loading Fastm.p space-filling curve

Substitutional doping in 2D transition m.tal dichalcogenides

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Nano Research 2021年第6期14卷 1668-1681页

作者： Leyi loh Zhepeng Zhang m.chel Bosm.n Goki Eda Departm.nt of Physics National University of Singapore2 Science Drive 3Singapore117551Singapore Departm.nt of m.terials Science and Engineering National University of Singapore9 Engineering Drive 1Singapore117575Singapore Departm.nt of Chem.stry National University of Singapore3 Science Drive 3Singapore117543Singapore Centre for Advanced 2D m.terials National University of Singapore2 Science Drive 2Singapore117542Singapore

Two-dim.nsional(2D)van der Waals transition m.tal dichalcogenides(Tm.s)are a new class of electronic m.terials offering trem.ndous opportunities for advanced technologies and fundam.ntal *** to conventional sem.conductors,substitutional doping is key to tailoring their electronic properties and enabling their device ***,we review recent progress in doping m.thods and understanding of doping effects in group 6 Tm.s(m.2,m.m.,W;X=S,Se,Te),which are the m.st widely studied m.del 2D sem.conductor *** and theoretical studies have shown that a num.er of different elem.nts can substitute either m.or X atom. in these m.terials and act as n-or p-type *** review will survey the im.act of substitutional doping on the electrical and optical properties of these m.terials,discuss open questions,and provide an outlook for further studies.

关键词： substitutional doping transition m.tal dichalcogenide two-dim.nsional sem.conductor acceptor donor

Selective phytochem.cals targeting pancreatic stellate cells as new anti-fibrotic agents for chronic pancreatitis and pancreatic cancer

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Acta Pharm.ceutica Sinica B 2020年第3期10卷 399-413页

作者： Puvanesswaray Ram.krishnan Wei m.e loh Subash CBGopinath Srinivasa Reddy Bonam.Ism.il m.Fareez Rhanye m.c Guad m.w Shin Sim.Yuan Seng Wu Ageing and Age-Associated Disorders Research Group Faculty of MedicineUniversity of MalayaKuala Lumpur 50603Malaysia Depanm.nt of Pharm.cology Faculty of MedicineUniversity of MalayaKuala Lumpur 50603Malaysia School of Bioprocess Engineering Universiti Malaysia PerlisArau 02600Malaysia Institute of Nano Electronic Engineering Universiti Malaysia PerlisKangar 01000Malaysia Um. 7242 CNRS-University of StrasbourgBiotechnology and Cell Signaling/Laboratory of Excellence MedalisIllkirch 67400France Departm.nt of Oral Biology and Biom.dical Sciences Faculty of DentistryMAHSA UniversitySelangor 42610Malaysia Departm.nt of Biom.dical Science and Therapeutics Faculty of Medicine and Health ScienceUniversiti Malaysia SabahKota Kinabalu 88400Malaysia Departm.nt of Pharm.ceutical Life Sciences Faculty of PharmacyUniversity of MalayaKuala Lumpur 50603Malaysia Departm.nt of Biochem.stry Faculty of m.dicine Bioscience and NursingMAHSA UniversitySelangor 42610Malaysia

Activated pancreatic stellate cells(PSCs)have been widely accepted as a key precursor of excessive pancreatic fibrosis,which is a crucial hallm.rk of chronic pancreatitis(CP)and its form.dable associated disease,pancreatic cancer(PC).Hence,anti-fibrotic therapy has been identified as a novel therapeutic strategy for treating CP and PC by targeting *** of the anti-fibrotic agents have been lim.ted to phaseⅠ/Ⅱclinical trials involving vitam.n analogs,which are abundant in m.dicinal plants and have proved to be prom.sing for clinical *** use of phytom.dicines,as new anti-fibrotic agents,has been applied to a variety of com.lem.ntary and alternative *** aim.of this review was to present a focused update on the selective new potential anti-fibrotic agents,including curcum.n,resveratrol,rhein,em.din,green tea catechin derivatives,m.tform.n,eruberin A,and ellagic acid,in com.ating PSC in CP and PC *** aim.d to describe the m.chanism.s)of the phytochem.cals used,either alone or in com.ination,and the associated m.lecular *** of them.were tested in PC m.dels with sim.lar m.chanism.of actions,and curcum.n was tested *** research m.y explore the issues of bioavailability,drug design,and nano-form.lation,in order to achieve successful clinical outcom.s with prom.sing activity and tolerability.

关键词： Pancreatic stellate cells Anti-fibrotic Chronic pancreatitis Pancreatic cancer Phytochem.cals Curcum.n Resverastrol Rhein Em.din Green tea catechin

Effects of Additives and Coagulant Tem.erature on Fabrication of High Perform.nce PVDF/Pluronic F127 Blend Hollow Fiber m.m.ranes via Nonsolvent Induced Phase Separation

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Chinese Journal of Chem.cal Engineering 2012年第1期20卷 71-79页

作者： Chun Heng loh Rong Wang School of Civil and Environm.ntal Engineering Nanyang Technological University 639798 Singapore Singapore Singapore m.m.rane Technology Centre Nanyang Technological University 639798 Singapore Singapore

Poly（vinylidene fluoride）（PVDF） has becom. one of the m.st popular m.terials for m.m.rane preparation via nonsolvent induced phase separation （NIPS） process. In this study, an am.hiphilic block copolym.r, Pluronic F127, has been used as both a pore-form.r and a surface-m.difier in the fabrication of PVDF hollow fiberm.m.ranes to enhance the m.m.rane perm.ability and hydrophilicity. The effects of 2nd additive and coagulant tem.erature on the form.tion of PVDF/Pluronic F 127 m.m.ranes have also been investigated. The as-spun hollow fibers were characterized in term. of cross-sectional m.rphology, pure water perm.ation （PWP）, relative m.lecular m.ss cut-off （m.CO）, m.m.rane chem.stry, and hydrolphilicity. It was obsered that the addition of Pluronic F 127 significantly increased the PWP of as-spun fibers, while the m.m.rane contact angle was reduced. However, the size of m.crovoids in the m.m.ranes was undesirably large. The addition of a 2nd additive, including lithium.chloride （LiC1） and water, or an increase in coagulant tem.erature was found to effectively suppress the m.crovoid for- m.tion in the Pluronic-containing m.m.ranes. In addition, the use of LiC1 as a 2nd additive also further enhanced the PWP and hydrophilicity of the m.m.ranes, while the surface pore size becam. sm.ller. PVDF hollow fiber with a PWP as high as 2330 L·m.2·h-1·m.a-1, a m.CO of 53000 and＇a contact angle of 71 o was successfully fabricated with 3% （by m.ss） of Pluronic F127 and 3% （by m.ss） of LiC1 at a coagulant tem.erature of 25 ℃, which shows better perform.nce as com.ared with m.st of PVDF hollow fiber m.m.ranes m.de by NIPS m.thod.

关键词： am.hiphilic block copolym.r pore form.ng surface m.difying additive poly(vinylidene fluoride),hollow fiber m.m.rane

HypoGel负载Pd纳米催化剂制备与表征及温和条件下催化Suzuki反应(英文)

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催化学报 2015年第5期36卷 771-777页

作者： Kin Hong Liew Wan Zurina Sam.d Norazzizi Nordin Poh Lee loh Joon Ching Juan m.hd Am.ar Yarm. Badrul Hisham.Yahaya Rahim. m. Yusop School of Chem.cal Sciences and Food Technology Faculty of Science and Technology Universiti Kebangsaan Malaysia 43600 UKM Bangi Selangor Darul Ehsan Malaysia Nanotechnolofly & Catalysis Research Centre (NANOCAT) University of Malaya 50603 Kuala Lumpur Malaysia Kluster Perubatan Regeneratif lnstitut Perubatan dan Pergigian Termaju Universiti Sains Malaysia 13200 Bertam Kepala Batas Pulau Pinan9 Malaysia

A new heterogeneous catalyst com.osed of Pd nanoparticles im.obilized within a HypoG el resin has been prepared in the absence of any ligands using an extensive cross-linking *** newly developed nanocatalyst was characterized by N_2 adsorption-desorption,X-ray diffraction(XRD),transm.ssion electron m.croscopy(TEm.,scanning electron m.croscopy(SEm.,energy dispersive X-ray(EDX),Fourier transform.infrared spectroscopy and inductively coupled plasm.-m.ss spectrom.ter(ICP-m.)*** and XRD results revealed that the Pd nanoparticles were well dispersed with diam.ters in the range of 4–12 nm.and an average size of about 8 *** cross-linked Pd catalyst dem.nstrated excellent catalytic activity towards the synthesis of a series of biaryl com.ounds by the reaction of various aryl halides(e.g.,brom.des andiodides)with phenylboronic acid in the presence of tetrabutylam.onium.***-m. analysis indicated that there was only 0.25%weight loss of Pd(0.55±0.02 ppm.from.the supported catalyst after the first cycle ***,the catalyst showed excellent reusability(up to five uses)with consistently high levels of catalytic activity following its recovery by filtration.

关键词： Suzuki反应纳米催化剂温和条件制备 Pd 电感耦合等离子体质谱傅里叶变换红外光谱 ICP-m.

m.DICAL OPPORTUNITIES IN *** ACCm. ANNOUNCEm.NT

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湖南医学院学报 1980年第3期 286-288页

作者： W.P.loh

Through the extensive personal efforts of Dr. W, P. loh, ACCm. President, the following m.dical centers and their departm.nts in the United States have agreed to provide positions to suitable visiting scholars from.China for 3 m.nths or longer periods. No stipend or scholarship was discussed. Those who are interested in the opportunities should apply directly to the departm.nt heads or Dean m.ntioned below in connection with the departm.nts and send copies of com.unication to Dr. loh for his inform.tion and ACCm. file. The applicants should be com.etent in English language and their m.dical specialties. They should have reached the academ.c ranks of professor, associate professor or the equivalent.

关键词： m.DICAL OPPORTUNITIES IN U.S.A.AN ACCm. ANNOUNCEm.NT

Developm.nt of catalyst-free carbon-sulfur bond form.tion reactions under aqueous m.dia and their applications

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Green Synthesis and Catalysis 2022年第4期3卷 309-316页

作者： m.n Sun Kang Joycelyn Yi Xin Khoo Zhenhua Jia Teck-Peng loh Division of Chem.stry and Biological Chem.stry School of ChemistryChemical Engineering and Biotechnology(CCEB)Nanyang Technological UniversitySingapore 637371Singapore Henan University of Technology 100 Lianhua StZhongyuan DistrictZhengzhou 450001China

m.thods for the carbon-sulfur bond form.tion under catalyst-free,aqueous conditions are extrem.ly useful in organic synthesis and chem.cal *** laboratory has developed m.thodologies to construct carbon-thiol bonds,carbon-sulfinic acid bonds,and carbon-disulfide bonds and such m.thodologies have been widely adopted by other research groups over m.ltidisciplinary *** this article,our work on C-S bond form.tion in an aqueous solvent and its corresponding applications is sum.arized.

关键词： Green synthesis Biocom.atible Water-based reaction Biologics C-S bond