检索结果-南通市图书馆

Reversible hydrogels with tunable mechanical properties for optically controlling cell migration

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第10期11卷 5556-5565页

作者： Xin Wu Wenmao Huang Wen-Hao Wu Bin Xue Dongfang Xiang Ying Li Meng Qin Fei Sun wei Wang Wen-Bin Zhang Yi cao Collaborative Innovation Center of Advanced Microstructures National Laboratory of Solid State Microstructure and Department of Physics Nanjing University Nanjing 210093 China Key Laboratory of Polymer chemistry & Physics of Ministry of Education Center for Soft Matter Science and Engineering College ot Chemistry and Molecular Engineering Peking University Beijing 100871 China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University olin formation Science & Technology Nanjing 210044 China Department of Chemical and Biomolecular engineering Division of BioMedical Engineering and Center for Systems Biology & Human Health The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong China

Synthetic hydrogels are widely used as biomimetic in vitro model systems to understand how cells respond to complex microenvironments. The mechanical properties of hydrogels are deterministic for many cellular behaviors, including cell migration, spreading, and differentiation. However, it remains a major challenge to engineer hydrogels that recapture the dynamic mechanical properties of native extracellular matrices. Here, we provide a new hydrogel platform with spatiotemporally tunable mechanical properties to assay and define cellular behaviors under light. The change in the mechanical properties of the hydrogel is effected by a photo-induced switch of the cross-linker fluorescent protein, Dronpa145N, between the tetrameric and monomeric states, which causes minimal changes to the chemical properties of the hydrogel. The mechanical properties can be rapidly and reversibly tuned for multiple cycles using visible light, as confirmed by rheological measurements and atomic force microscopy- based nano-indentation. We further demonstrated real-time and reversible modulation of cell migration behaviors on the hydrogels through photo-induced stiffness switching, with minimal invasion to the cultured cells. Hydrogels with a programmable mechanical history and a spatially defined mechanical hierarchy might serve as an ideal model system to better understand complex cellular functions.

关键词： Dronpa photo-responsive hydrogel mechanical properties cell migration artificial extracellular matrix

Tire pyrolysis wastewater treatment by a combined process of coagulation detoxification and biodegradation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Environmental Science and Ecotechnology 2021年第4期8卷 94-101页

作者： xiao-ran Shen Chun-Xiang Geng Bing-Qian Lv wei Xu Yi Xu Hua-Zhang Zhao Key Laboratory of Water and Sediment Sciences(Ministry of Education) College of Environmental Sciences and EngineeringPeking UniversityBeijing100871People's Republic of China college of chemistry and Chemical engineering China University of PetroleumQingdao266555People's Republic of China

Recycling waste tires through pyrolysis technology generates refractory wastewater,which is harmful to the environment if not disposed *** this study,a combined process of coagulation detoxification and biodegradation was used to treat tire pyrolysis *** removal characteristics at the molecular level were investigated using electrospray ionization(ESI)coupled with Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS).The results showed that nearly 90%of the organic matter from the wastewater was removed through the *** of the two coagulants for different classes of organics in tire pyrolysis wastewater was *** covalently bound inorganicorganic hybrid coagulant(CBHyC)used in this work had a complementary relationship with biodegradation for the organics removal:this coagulant reduced toxicity and enhanced the biodegradation by preferentially removing refractory substances such as lignin with a high degree of oxidation(O/C>0.3..This study provides molecular insight into the organics of tire pyrolysis wastewater removed by a combined treatment process,supporting the advancement and application of waste rubber recycling *** also contributes to the possible development of an effective treatment process for refractory wastewater.

关键词： Refractory wastewater molecular composition Recalcitrant substances Biodegradability ESI FT-ICR MS

Impeded degradation of perovskite solar cells via the dual interfacial modification of siloxane

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china chemistry 2022年第11期65卷 2299-2306页

作者： xiao Zhang Changsu cao Yang Bai Cheng Zhu Huachao Zai Sai Ma Yihua Chen Zhenhua Cui Congbo Shi Chenyue Wang Chenxiao Zhou Guizhou Yuan Ziyan Gao Jiawang Hong Jie Dou Hao Wang Huanping Zhou Hai xiao Jun Li Qi Chen Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing100081China Experimental Center of Advanced Materials School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Department of chemistry and Key Laboratory of Organic Optoelectronics and molecular engineering of Ministry of Education Tsinghua UniversityBeijing 100084China Department of chemistry Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and engineering College of EngineeringPeking UniversityBeijing 100871China Shanghai Synchrotron Radiation Facility(SSRF) Zhangjiang LabShanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China School of Aerospace engineering Beijing Institute of TechnologyBeijing 100081China

It is challenging to improve the long-term stability of perovskite solar cells(PSCs) without sacrificing efficiency. The perovskite absorbers degrade from the film surface/interfaces, which follows entangled mechanisms that have not been fully revealed ***, we decouple and elaborate two distinctive pathways regarding film degradation based on ***, a dual interfacial modification strategy has been developed for improving the material’s intrinsic stability, thus leading to the film degrading in a more retardant pathway. The corresponding PSCs achieve a stable power output efficiency of 23.75%.More importantly, the unencapsulated PSCs devices retain over 93. of their initial PCE after the maximum power point(MPP)tracking under the continuous 1-sun illumination and show significantly improved stability after aged under the thermal treatment or stored in ambient atmosphere for over 1500 hours without obvious PCE decay. This work shows the importance of modulating the degradation pathway on stability improvement, and at the same time, proposes a strategy for designing perovskite-based optoelectronics with excellent performance and stability.

关键词： perovskite solar cells stability degradation kinetics

Synthesis of Novel Derivatives of (R)-Cysteine and Their Application in Asymmetric Reduction of Prochiral Ketones

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2005年第5期21卷 536-539页

作者： WANG Hui PEI wei-wei YE wei-ping The Key Laboratory of Bioorganic chemistry and molecular engineering of Ministry of Education College of Chemistry and Molecular Engineering Peking University Beijing 100871 P. R. China

ovel chiral β-amino alcohols containing sulfide or sulfonyl groups were synthesized from （R）-cysteine. Their chiral induction in the asymmetric borane reduction of prochiral ketones was investigated. Optically active secondary alcohols with moderate or high e. e. values were obtained, and the causes of different enantioselectivities between these two sulfur-containing chiral β-amino alcohols were researched.

关键词： (R)-Cysteine Sulfide Sulfone Synthesis Asymmetric reduction

Silica nanoparticle with a single His-tag for addressable functionalization, reversible assembly, and recycling

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第5期11卷 2512-2522页

作者： Yuye cao Yangdong Cui Yu Yang Jie Hua Zheng-Mei song Haifang Wang Yuanfang Liu Aoneng cao Institute of Nanochemistry and Nanobiology Shanghai University Shanghai 200444 China Beijing National Laboratory for molecular Sciences College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

For many biomedical and catalytic applications, such as encapsulation of proteins/enzymes in nanopartides （NPs）, it is preferable to have well-dispersed small NPs that are stable in solution and behave quasi-homogeneously. However, conventional liquid phase methods for small-NP synthesis and functionalization usually face great difficulties in separation/purification and recycling. In addition, controlling the orientation of proteins inside NPs is also a crucial issue to maximize the activity of the encapsulated proteins. Herein, we report a solid phase method to solve these problems. Using His-tagged proteins as cores, well-dispersed core-sheU silica NPs are facilely synthesized and functionalized in a column. The core His-tagged proteins are kept bound on the surface of the resIn beads in the column during the entire process, making the separation/purification of NPs and their precursors during the multiple-step process as simple as a few-minutes procedure of draining and washing the column. Each obtained silica NP has an adjustable eccentric core-shell structure with only one His-tag sticking out of the particle. This single His-tag on the surface of each NP not only makes it easy for addressable and stoichiometric functionalization of the NP but also provides an easy way to reversibly assemble NPs into dimers or be oriented on the surface of large particles. Notably, this solid phase approach also provides a versatile means to control the orientation of proteins inside NPs, and the His-tag makes it easy to recycle those well-dispersed small NPs.

关键词： His-tagged nanoparticle solid phase reversible assembly addressable functionalization protein orientation

Pathological features of COVID-19-associated liver injury-a preliminary proteomics report based on clinical samples

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2021年第2期6卷 229-231页

作者： Ling Leng Ruiyuan cao Jie Ma Luye LV wei Li Yunping Zhu Zhihong Wu Manli Wang Yiwu Zhou Wu Zhong Stem Cell and Regenerative Medicine Lab Translational Medicine CenterDepartment of Medical Science Research CenterPeking Union Medical College HospitalPeking Union Medical College and Chinese Academy of Medical SciencesBejing 100730China National engineering Research Center for the Emergency Drug Beijig Institute of Pharmacology and ToxicologyBeijing 100850China State Key Laboratory of Proteomics Bejing Proteome Research CenterNational Center for Protein Sciences(Beijing)Bejing Institute of Life OmicsBeijing 102206China Institute of NBC Defense Beijing 102205China State Key Laboratory of Virology Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan 430071China Department of Forensic Medicine Tongji Medical College of Huazhong University of Science and TechnologyWuhan 430030China

Dear Editor,Almost one-half of COVID-19 patients have symptoms of liver ***,the molecular characteristics in the COVID-19 liver remain ***,the need for long-term medication for recovery make it imperative to study the infectivity and pathogenicity of SARS-CoV-2 in the ***,we have identifed signifcant proteomic changes for the first time in the liver of COVID-19 *** detected differential expression levels of several proteins that mediate characteristic cellular host responses elicited by SARS-CoV-2 infection in the liver.

关键词： liver patients medication

Carbon nanotube-polypyrrole core-shell sponge and its application as highly compressible supercapacitor electrode

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2014年第2期7卷 209-218页

作者： Peixu Li Enzheng Shi Yanbing Yang Yuanyuan Shang Qingyu Peng Shiting Wu Jinquan wei Kunlin Wang Hongwei Zhu Quan Yuan Anyuan cao Dehai Wu Department of Mechanical engineering Tsinghua University Beijing 100084 China Department of Materials Science and engineering College of Engineering Peking University Beijing 100871 China Key Laboratory of Analytical chemistry for Biology and Medicine (Ministry of Education) College of Chemistry and Molecular Sciences Wuhan University Wuhan 430072 China Key Laboratory for Advanced Materials Processing Technology and School of Materials Science and engineering Tsinghua University Beijing 100084 China

A carbon nanotube （CNT） sponge contains a three-dimensional conductive nano- tube network, and can be used as a porous electrode for various energy devices. We present here a rational strategy to fabricate a unique CNT@polypyrrole （PPy） core-shell sponge, and demonstrate its application as a highly compressible supercapacitor electrode with high performance. A PPy layer with optimal thickness was coated uniformly on individual CNTs and inter-CNT contact points by electrochemical deposition and crosslinking of pyrrole monomers, resulting in a core-shell configuration. The PPy coating significantly improves specific capacitance of the CNT sponge to above 3.0 F/g, and simultaneously reinforces the porous structure to achieve better strength and fully elastic structural recovery after compression. The CNT@PPy sponge can sustain 1,000 compression cycles at a strain of 50% while maintaining a stable capacitance （〉 90% of initial value）. Our CNT@PPy core-shell sponges with a highly porous network structure may serve as compressible, robust electrodes for supercapacitors and many other energy devices.

关键词： carbon nanotube sponge polypyrrole core-shell configuration compressible electrode supercapacitor

还原条件下非对称钳形PNN钴配合物的反应性研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

化学学报 2024年第5期82卷 471-476页

作者：陈元金黄大江石向辉席振峰魏俊年北京大学化学与分子工程学院、北京分子科学国家研究中心、生物有机与分子工程教育部重点实验室北京100871

本工作报道了还原条件下,非对称钳形钴配合物PNNCoCl(1)(PNN:[6-(^(t)Bu_(2)PN)C_(5)H_(3.N-2-(3.Mes)C_(3.H_(2)N_(2)])和有机分子的反应性.利用PNNCoCl、还原剂与异腈或一氧化碳反应,实现了异腈和一氧化碳配位一价钴配合物2和3.合成.通过更换还原剂,实现了偶氮苯C—H、N=N键的选择性断裂反应.当使用石墨钾作为还原剂时,PNNCoCl(1)与偶氮苯在四氢呋喃中反应,得到偶氮苯C—H键断裂产物5;而当使用KHBEt_(3.作为还原剂时,PNNCoCl与偶氮苯反应,则能得到偶氮苯N=N键断裂产物PNNCoNHPh(6).此外,PNNCoCl(1)还可以与卡宾或邻苯醌反应,得到了相应配合物4和7.这些配合物均通过了X射线衍射、元素分析、红外光谱和溶液相磁化率测试等表征.

关键词：钳形配体钴配合物小分子活化低价金属配合物

High activity of Mj HSP16.5 under acidic condition

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2009年第3期52卷 325-331页

作者： WANG Zheng cao AoNeng LAI LuHua Beijing National Laboratory for molecular Sciences and State Key Laboratory of Structural Chemistry for Stable and Unstable SpeciesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Institute of Nanochemistry and Nanobiology Shanghai UniversityShanghai 200444China

Small heat shock proteins (sHSPs) exist ubiquitously among all organisms, with a variety of functions. All small heat shock proteins assemble into a native large oligomeric state containing 9–40 monomers. The sHSPs show chaperone-like activity to prevent the aggregation of nonnative proteins under stressful cellular conditions such as non-optimal temperatures, pH changes, osmotic pressure, and exposure to toxic chemicals. It was found that a common dimeric subunit of sHSPs might be the major active species, but whether the native large oligomeric state is only a storage state or a state crucial to its molecular chaperone activity is still under debate. The native large oligomeric state of the small heat shock protein from a hyperthermophilic methanarchaeon, Methanococcus jannaschii (Mj HSP 16.5), is a stable icositetramer, which is a symmetric hollow sphere that is very stable even at 85°C, and no small active subunit has been detected till now. Our results show that Mj sHSP 16.5 changes into small and active oligomeric state at pH 3. likely as octamers (average result) at 25°C, and dimers at 65°C. The dimer of Mj HSP 16.5 at pH 3.0 and 65°C is very active and efficient, even 7-fold more efficient than the high-temperature-activated icositetramer at neutral pH. Monomer exchange can be observed between dimers of Mj HSP 16.5 at pH 3.0 and 65°C. These results not only demonstrate that the icositetramer structure of Mj sHSP16.5 is not necessary for its molecular chaperone activity, but also suggest that Mj sHSP16.5 is a very efficient chaperone acting at high temperature and under the acidic condition. Even though it is not clear whether the native environment of Methanococcus jannaschii is acidic or not, given its ability to excrete acidic compounds, it is likely that Methanococcus jannaschii will encounter acidic internal or external environments at high temperature. Our results demonstrate that Mj HSP 16.5 may help Methanococcus jannaschii to survive better under tho

关键词： small heat shock protein chaperone Mj HSP16.5 dimer acidic folding aggregation