检索结果-南通市图书馆

Fabrication of Molecularly Imprinted Electrospun Nanofibers with Mono-amidoxime Functional Ligand for Efficient Decontamination of Toxic Organophosphates

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第4期42卷 446-456页

作者： Lan wang peng Jiang Ya-Lin Niu Jun-peng Cao tian-Ying Guo Key Laboratory of Functional Polymer Materials Ministry of EducationInstitute of Polymer ChemistryCollege of Chemistry and Frontier Science Center for the Creation of New Organic SubstancesNankai UniversityTianjin300071China

There is an urgent imperative to discover practical and efficacious artificial catalysts for the expeditious decontamination of toxic organophosphates. Herein, we propose a novel molecularly imprinted approach utilizing electrospun fiber scaffolds. Specifically, an amidoxime-based functional polymer (PMAOX) has been synthesized, which contains amidoxime groups that can act as nucleophiles and ligands for the formation of catalytic active sites. This polymer was blended with polyacrylonitrile (PAN), a well-processable material, to prepare a nanofiber mat using electrospinning techniques. Then, the amidoxime side groups on fiber surface were further cross-linked after the molecular coordination of templates to complete the molecularly imprinting process. This approach can not only enhance the content of functional molecularly imprinted polymers without affecting structural stability, but also combines surface MI technology to fully expose and leverage the advantages of active sites. The as prepared molecularly imprinted electrospun nanofibers MIF-Zn-PMAOX/PAN-6/4 catalyzes the degradation of paraoxon with a half-life of 32 min, and MIF-Ag-PMAOX/PAN catalyzes the degradation of parathion with a half-life of 18 min. The maximum catalytic rate evidence rate enhancements nearly 3700-fold of the self-hydrolysis. Thus, the mono-amidoxime based molecularly imprinted fibers demonstrate the versatility and superiority as self-detoxifying for organophosphates.

关键词： Organophosphateshydrolysis Electrospinning Molecular imprinting

Co-influence of the start of thermal growing season and precipitation on vegetation spring green-up on the Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第2期15卷 327-337页

作者： Chen-peng wang Meng-tian HUANG Pan-Mao ZHAI State Key Laboratory of Severe Weather and Institute of Global Change and Polar Meteorology Chinese Academy of Meteorological SciencesBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China

The climate in the Tibetan Plateau(TP)has undergone significant change in recent decades,mainly in thermal and water conditions,which plays a crucial role in phenological changes in vegetation spring ***,how the start of the thermal growing season(SOS-T)and the start of the rainy season(SORS)as key climatic factors affect vegetation green-up remains *** that these factors characterize thermal and water conditions required for vegetation green-up,this study investigated changes in the SOS-T and SORS from 1961 to 2022,using observation-based datasets with long time *** found that the SOS-T and SORS have advanced across the TP in 1961-2022 and have shown a spatial pattern of advancement in the east and delay in the west in ***,the co-effect of temperature and precipitation change on the start of vegetation growing season(SOS-V)in 2000-2022 was *** across TP,the SOS-V had an early onset of 1.3 d per decade during 2000-2022,corresponding to advanced SOS-T and ***,the SOS-V generally occurred nearly at the same time as the SOS-T in the high-altitude meadow region.A substantial delay in the SOS-V relative to the SOS-T was observed in the desert,shrub,grassland and forest regions and generally kept pace with the ***,for 50%of the vegetated regions on the TP,inter-annual variation in the delay in the SOS-V relative to the SOS-T was dominated by precipitation change,which was profound in warm-climate *** study highlights the co-regulation of precipitation and temperature change in the SOS-V in different vegetation cover regions in the TP,offering a scientific foundation for comprehending the impact of climate change and prospects for vegetation phenology on the TP.

关键词： Tibetan Plateau Start of growing season Temperature Precipitation Climate change

Improving corrosion resistance of additively manufactured WE43 magnesium alloy by high temperature oxidation for biodegradable applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第3期12卷 940-953页

作者： Jinge Liu Bangzhao Yin Fei Song Bingchuan Liu Bo peng peng Wen Yun tian Yufeng Zheng Xiaolin Ma Caimei wang State Key Laboratory of Tribology in Advanced Equipment Beijing100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Department of Orthopaedics Beijing Tsinghua Changgung HospitalInstitute for Precision MedicineTsinghua UniversityBeijing102218China Department of Orthopaedics Peking University Third HospitalBeijing 100191China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing 100191China School of Materials Science and Engineering Peking UniversityBeijing 100871China Beijing AKEC Medical Co. Ltd.Beijing 102200China

Laser powder bed fusion(L-PBF)has been employed to additively manufacture WE43 magnesium(Mg)alloy biodegradable implants,but WE43 L-PBF samples exhibit excessively rapid *** this work,dense WE43 L-PBF samples were built with the relativity density reaching 99.9%.High temperature oxidation was performed on the L-PBF samples in circulating air via various heating temperatures and holding *** oxidation and diffusion at the elevated temperature generated a gradient structure composed of an oxide layer at the surface,a transition layer in the middle and the *** oxide layer consisted of rare earth(RE)oxides,and became dense and thick with increasing the holding *** matrix was composed ofα-Mg,RE oxides and Mg_(24)RE_(5) *** precipitates almost disappeared in the transition *** passivation effect was observed in the samples treated by a suitable high temperature *** original L-PBF samples lost 40%weight after 3-day immersion in Hank’s solution,and broke into fragments after 7-day *** casted and solution treated samples lost roughly half of the weight after 28-day *** high temperature oxidation samples,which were heated at 525℃ for 8 h,kept the structural integrity,and lost only 6.88%weight after 28-day *** substantially improved corrosion resistance was contributed to the gradient structure at the *** one hand,the outmost dense layer of RE oxides isolated the corrosive medium;on the other hand,the transition layer considerably inhibited the corrosion owing to the lack of ***,high temperature oxidation provides an efficient,economic and safe approach to inhibit the corrosion of WE43 L-PBF samples,and has promising prospects for future clinical applications.

关键词： Laser powder bed fusion Biodegradable magnesium alloy High temperature oxidation Corrosion resistance WE43.

Influence of layer thickness on formation quality,microstructure,mechanical properties,and corrosion resistance of WE43 magnesium alloy fabricated by laser powder bed fusion

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第4期12卷 1367-1385页

作者： Bangzhao Yin Jinge Liu Bo peng Mengran Zhou Bingchuan Liu Xiaolin Ma Caimei wang peng Wen Yun tian Yufeng Zheng State Key Laboratory of Tribology in Advanced Equipment Beijing100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Institute for Precision Medicine Tsinghua UniversityBeijing102218China Department of Orthopaedics Peking University Third HospitalBeijing 100191China Beijing AKEC Medical Co. Ltd.Beijing 102200China School of Materials Science and Engineering Peking UniversityBeijing 100871China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing 100191China

Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical *** thickness(LT)is of great significance to the L-PBF process but has not been studied for Mg *** this study,WE43 Mg alloy bulk cubes,porous scaffolds,and thin walls with layer thicknesses of 10,20,30,and 40μm were *** required laser energy input increased with increasing layer thickness and was different for the bulk cubes and porous *** tended to occur at the connection joints in porous scaffolds for LT40 and could be eliminated by reducing the laser energy *** thin wall parts,a large overhang angle or a small wall thickness resulted in porosity when a large layer thicknesses was used,and the porosity disappeared by reducing the layer thickness or laser energy input.A deeper keyhole penetration was found in all occasions with porosity,explaining the influence of layer thickness,geometrical structure,and laser energy input on the *** the samples achieved a high fusion quality with a relative density of over 99.5%using the optimized laser energy *** increased layer thickness resulted to more precipitation phases,finer grain sizes and decreased grain *** the similar high fusion quality,the tensile strength and elongation of bulk samples were significantly improved from 257 MPa and 1.41%with the 10μm layer to 287 MPa and 15.12%with the 40μm layer,in accordance with the microstructural *** effect of layer thickness on the compressive properties of porous scaffolds was ***,the corrosion rate of bulk samples accelerated with increasing the layer thickness,mainly attributed to the increased number of precipitation phases.

关键词： Magnesium alloy WE43 Laser powder bed fusion Layer thickness Process optimization

High-entropy oxide-supported platinum nanoparticles for efficient hydrogen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1537-1546页

作者： Ming-Yu Fan Jia-Jun wang Jun Zhao Hong Zhang tian-Yi Ma Xiao-peng Han Wen-Bin Hu School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional Materials Key Laboratory of Advanced Ceramics and Machining TechnologyTianjin UniversityTianjin300350China Joint School of National University of Singapore and tianjin University International Campus of Tianjin UniversityFuzhou350207China School of Science RMIT UniversityMelbourneVIC3000Australia

High-entropy oxides(HEOs)are a new class of single-phase structures with unique electronic and catalytic properties;therefore,it is worthwhile to explore their applications in *** this study,a Pt/(FeCoNiCrAl)_(3)O_(4)nanohybrid using HEO as a support was developed as an efficient catalyst for the hydrogen evolution reaction(HER).Pt/(FeCoNiCrAl)_(3)O_(4)exhibited high HER activity with a low overpotential of 22 mV at10 mA·cm^(-2),outperforming other binary,ternary,and quaternary *** HER activity of Pt/(FeCoNiCrAl)_(3)O_(4)was higher than that of a commercial Pt/C with a significantly lower Pt *** catalyst exhibited good activity and long-term stability(60 h)in an electrolytic water-splitting *** good activity can be attributed to the fact that the introduction of Pt effectively facilitates electronic interactions between Pt and the *** addition,the HEO substrate was more favorable for dispersing Pt particles,optimizing the electrochemical specific surface area,and significantly reducing the charge resistance of the *** study extends the application of HEOs in electrocatalysis and demonstrates the promising prospects of HEOs as supports for electrocatalysts.

关键词： High-entropy oxides Hydrogen evolution reaction Nanohybrid Water electrolysis

Regio-and Stereoselective Polymerization of Bio-based Ocimene by Rare-Earth Metal Catalysts

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 223-229,I0008页

作者： Qi-Yuan wang Li-peng Sang Zhen Zhang Yang Jiang Hui tian Xia Zhao Xiang Guo Shi-Hui Li State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechonologyXiangyang441003China Shanxi Coal Chemical Industry Technology Research Institute Xi’an710000China Hubei Institute of Aerospace Chemotechonology Xiangyang441003China

Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-sandwich benzyl fluorenyl scandium complex 4 and pyridyl-methylene-fluorenyl rare-metal complexes 5a–5c. Complexes 1, 4 and 5a–5c show trans-1,2-regioselectivities and high activities, of which 5c exhibits excellent isoselectivity(mmmm>99%). Conversely, complexes 2 and 3 promote β-ocimene polymerization to produce isotactic cis-1,4-polyocimenes(cis-1,4>99%, mm>95%). Diblock copolymers cis-1,4-PIP-block-cis-1,4-POc and cis-1,4-PBD-block-cis-1,4-POc are obtained in one-pot reactions of β-ocimene with isoprene and butadiene using complex 3. Epoxidation and hydroxylation of polyocimene afford functionalized polyolefins with enhanced T_(g)(from-20 ℃ to 79 ℃ and 74 ℃) and hydrophilicity.

关键词： Biobased monomer Terpenes Ocimene Rare-earths Polymerization Regio/stereoselectivity Elastomer

Development of SV2A Ligands for Epilepsy Treatment:A Review of Levetiracetam,Brivaracetam,and Padsevonil

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2024年第5期40卷 594-608页

作者： peng-peng Wu Bi-Rong Cao Fu-Yun tian Zhao-Bing Gao Center for Neurological and Psychiatric Research and Drug Discovery Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China University of Chinese Academy of Sciences Beijing100049China Zhongshan Institute for Drug Discovery Shanghai Institute of Materia MedicaChinese Academy of SciencesZhongshan528400China

Epilepsy is a common neurological disorder that is primarily treated with antiseizure medications(ASMs).Although dozens of ASMs are available in the clinic,approximately 30%of epileptic patients have medically refractory seizures;other limitations in most traditional ASMs include poor tolerability and drug-drug ***,there is an urgent need to develop alternative ***(LEV)is a first-line ASM that is well tolerated,has promising efficacy,and has little drug-drug *** it is widely accepted that LEV acts through a unique therapeutic target synaptic vesicle protein(SV)2A,the molecular basis of its action remains *** so,the next-generation SV2A ligands against epilepsy based on the structure of LEV have achieved clinical *** review highlights the research and development(R&D)process of LEV and its analogs,brivaracetam and padsevonil,to provide ideas and experience for the R&D of novel ASMs.

关键词： Levetiracetam Epilepsy Antiseizure medications Synaptic vesicle protein 2A Brivaracetam Padsevonil

Rational Engineering of Secondary Metabolic Pathways in a Heterologous Host to Enable the Biosynthesis of Hibarimicin Derivatives with Enhanced Anti-Melanomic Activity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2024年第7期38卷 113-123页

作者： Xiangyang Liua Fei-peng Zhao tian tian Wei-Chen wang Zaizhou Liu Qiang Zhou Xian-Feng Hou Jing wang Wenli Guo Shuangjun Lin Yasuhiro Igarashi Gong-Li Tang State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China State Key Laboratory of Microbial Metabolism&Joint International Research Laboratory on Metabolic and Developmental Sciences School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China Biotechnology Research Center Toyama Prefectural UniversityImizu 939-0398Japan

A 61-kb biosynthetic gene cluster(BGC),which is accountable for the biosynthesis of hibarimicin(HBM)B from Microbispora rosea *** TP-A0121,was heterologously expressed in Streptomyces coelicolor M1154,which generated a trace of the target products but accumulated a large amount of shunt *** on rational analysis of the relevant secondary metabolism,directed engineering of the biosynthetic pathways resulted in the high production of HBM B,as well as new HBM derivates with improved antitumor *** results not only establish a biosynthetic system to effectively synthesize HBMs-a class of the largest and most complex Type-Ⅱpolyketides,with a unique pseudo-dimeric structure-but also set the stage for further engineering and deep investigation of this complex biosynthetic pathway toward potent anticancer drugs.

关键词： Hibarimicin Biosynthesis Heterologous expression Biosynthetic gene cluster Rational engineering Type-II polyketide

A fungal CYP from Beauveria bassiana with promiscuous steroid hydroxylation capabilities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第5期35卷 218-222页

作者： Yu peng Yue wang tian-Jiao Chen Jing-Jing Chen Jin-Ling Yang Ting Gong Ping Zhu State Key Laboratory of Bioactive Substance and Function of Natural Medicines NHC Key Laboratory of Biosynthesis of Natural ProductsCAMS Key Laboratory of Enzyme and Biocatalysis of Natural DrugsInstitute of Materia MedicaChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China

Hydroxylation of steroid core is critical to the synthesis of steroid *** sp^(3) C-H hydroxylation is challenging through chemical catalysis,alternatively,fungal biotransformation offers a possible solution to this ***,mining and metabolic engineering of cytochrome P450 monooxygenases(CYPs)is usually regarded as a more eco-friendly and efficient ***,we report the mining and identification of a new steroid CYP(CYP68BE1)from Beauveria bassiana by transcriptomics,heterologous expression,in vivo and in vitro functional *** catalytic promiscuity of CYP68BE1 was explored,and CYP68BE1 showed promiscuously and catalytically versatile,which is qualified for monohydroxylation on C11α,C1α,C6βand dihydroxylation on C1β,11αand C6β,11αof six steroids,leading to the production of key steroid intermediates required in the industrial synthesis of some indispensable steroid *** dynamics simulations were performed,revealing the molecular basis of different binding orientations of CYP68BE1 with different *** discovery of CYP68BE1 offers a promising biocatalyst for enriching the steroid structural and functional diversity,which also can be applied to biosynthesize valuable steroid drug intermediates.

关键词： Fungal CYPs Steroid hydroxylase Beauveria bassiana Promiscuous biocatalyst Molecular dynamics