检索结果-南通市图书馆

Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation

National Science Review 2024年第2期11卷 155-167页

作者： Peng He Meng-Yang Hu Jin-Hong Li Tian-Zhang Qiao Yi-Lin Lu Shou-Fei Zhu Frontiers Science Center for New Organic matter State Key Laboratory and Institute of Elemento-Organic Chemistry Nankai University

Iron catalysts are ideal transition metal catalysts because of the Earths abundant, cheap, biocompatible features of iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively,and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.

关键词： spin effect spin-delocalization spin crossover iron-catalysis alkyne hydrosilylation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Programmable synthetic receptors:the next-generation of cell and gene therapies

引用

Signal Transduction and Targeted Therapy 2024年第2期9卷 376-400页

作者： Fei Teng Tongtong Cui Li Zhou Qingqin Gao Qi Zhou Wei Li University of Chinese Academy of Sciences Beijing 101408China State Key Laboratory of Stem cell and Regenerative Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China institute for Stem cell and Regeneration Chinese Academy of SciencesBeijing 100101China Beijing institute for Stem cell and Regenerative Medicine Beijing 100101China

cell and gene therapies hold tremendous promise for treating a range of difficult-to-treat diseases.However,concerns over the safety and efficacy require to be further addressed in order to realize their full potential.Synthetic receptors,a synthetic biology tool that can precisely control the function of therapeutic cells and genetic modules,have been rapidly developed and applied as a powerful solution.Delicately designed and engineered,they can be applied to finetune the therapeutic activities,i.e.,to regulate production of dosed,bioactive payloads by sensing and processing user-defined signals or biomarkers.This review provides an overview of diverse synthetic receptor systems being used to reprogram therapeutic cells and their wide applications in biomedical research.With a special focus on four synthetic receptor systems at the forefront,including chimeric antigen receptors(CARs)and synthetic Notch(synNotch)receptors,we address the generalized strategies to design,construct and improve synthetic receptors.Meanwhile,we also highlight the expanding landscape of therapeutic applications of the synthetic receptor systems as well as current challenges in their clinical translation.

关键词： synthetic landscape payload

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Drug repurposing: A novel strategy to target cancer stem cells and therapeutic resistance

引用

Genes & Diseases 2024年第1期11卷 148-175页

作者： Divya Ajmeera Rajanna Ajumeera cell Biology Department ICMR-National Institute of Nutrition(NIN)HyderabadTelangana 500007India

Chemotherapy is an effortless and frequently used approach in cancer therapy.However,in most cases,it can only prolong life expectancy and does not guarantee a complete cure.Furthermore,chemotherapy is associated with severe adverse effects,one of the major complications of effective cancer therapy.In addition,newly published research outputs show that cancer stem cells are involved in cancer disease progression,drug resistance,metastasis,and recurrence and that they are functional in the trans-differentiation capacity of cancer stem cells to cancer cells in response to treatments.Novel strategies are therefore required for better management of cancer therapy.The prime approach would be to synthesize and develop novel drugs that need extensive resources,time,and endurance to be brought into therapeutic use.The subsequent approach would be to screen the anti-cancer activity of avail-able non-cancerous drugs.This concept of repurposing non-cancer drugs as an alternative to current cancer therapy has become popular in recent years because using existing anticancer drugs has several adverse effects.Micronutrients have also been investigated for cancer ther-apy due to their significant anti-cancer effects with negligible or no side effects and availabil-ity in food sources.In this paper,we discuss an ideal hypothesis for screening available non-cancerous drugs with anticancer activity,with a focus on cancer stem cells and their clinical application for cancer treatment.Further,drug repurposing and the combination of micronu-trients that can target both cancers and cancer stem cells may result in a better therapeutic approach leading to maximum tumor growth control.

关键词： Cancerstem cells Chemotherapy Combination therapy micronutrients Non-cancer drugs Novel strategies

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Physical exercise and traumatic brain injury: is it question of time?

引用

Neural Regeneration Research 2024年第3期19卷 475-476页

作者： Valentina Mastrorilli Stefano Farioli Vecchioli institute of Biochemistry and cell Biology Institute of Biochemistry and Cell BiologyNational Research Council(IBBC/CNR)MonterotondoRomeItaly Plaisant S.R.L. RomeItaly

Is it better to be safe than sorry?This Hamletic dilemma has always stimulated medical-scientific debates in numerous fields of biomedicine.And among these,the preventive-therapeutic approach to the treatment of brain trauma is one of the most striking examples.Traumatic brain injury(TBI)is a leading cause of brain damage among young and elderly populations with a very high hospitalization and death rate.TBI is characterized by two pathologically distinct but strictly consequential phases:a first characterized by an immediate and highly variable mechanical dysfunction of the brain tissue,which involves widespread cell death and tissue degeneration,followed by a second phase which can last from days to even years depending on the severity of the TBI and the patient’s pre-existing health status.Secondary processes,including inflammatory phenomena,oxidative stress associated with metabolic,vascular,and neuro-modulatory deficits,are very often responsible for neuro-motor and psychological deficits leading to long-term disabilities(Kaur and Sharma,2018).

关键词： injury striking modulator

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules

引用

Nano-Micro Letters 2024年第7期16卷 74-97页

作者： Wei Guo Linhui Yu Ling Tang Yan Wan Yangming Lin CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China institute of Urban Environment Chinese Academy of SciencesXiamen 361021People’s Republic of China

Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and sustainability.Over the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction mechanisms.However,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental methods.In this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon catalysis.Using both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically studied.Combined with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular level.Furthermore,the outlook of model carbon catalysis has also been proposed in this work.

关键词： Metal-free carbon catalysts Model catalyst Electrocatalysis Active site Reaction mechanisms

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Angiogenesis in diseases:A half-century excursion from the initial therapeutic concept to current clinical benefits

引用

Chinese Medical Journal 2024年第6期137卷 636-637页

作者： Yihai Cao Department of Microbiology Tumor and Cell BiologyKarolinska InstituteStockholm 17177Sweden

Except a few tissues such as the cornea and cartilage that are avascular,blood vessels constitute a significant proportion of tissue masses in virtually all organs.Under physiological conditions,the adult vasculature remains quiescent to retain tissue and organ homeostatic functions.Too few or too many blood vessels are associated with the onset and progression of many diseases.In response to injuries,most tissues undergo repair by switching on angiogenesis,a key process of new blood vessel formation.^([1])Similarly,angiogenesis is often active in pathological tissues,including tumors and ischemic tissues to aggravate disease progression.

关键词： injuries organs diseases

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

One-step cell biomanufacturing platform:porous gelatin microcarrier beads promote human embryonic stem cell-derived midbrain dopaminergic progenitor cell differentiation in vitro and survival after transplantation in vivo

引用

Neural Regeneration Research 2024年第2期19卷 458-464页

作者： Lin Feng Da Li Yao Tian Chengshun Zhao Yun Sun Xiaolong Kou Jun Wu Liu Wang Qi Gu Wei Li Jie Hao Baoyang Hu Yukai Wang State Key Laboratory of Stem cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijingChina institute for Stem cell and Regenerative Medicine Chinese Academy of SciencesBeijingChina National Stem cell Resource Center Chinese Academy of SciencesBeijingChina Savaid Medical School University of Chinese Academy of SciencesBeijingChina Beijing institute for Stem cell and Regenerative Medicine BeijingChina State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijingChina

Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a promising treatment for Parkinson’s disease.However,transplanted cells can be injured by mechanical damage during handling and by changes in the transplantation niche.Here,we developed a one-step biomanufacturing platform that uses small-aperture gelatin microcarriers to produce beads carrying midbrain dopaminergic progenitor cells.These beads allow midbrain dopaminergic progenitor cell differentiation and cryopreservation without digestion,effectively maintaining axonal integrity in vitro.Importantly,midbrain dopaminergic progenitor cell bead grafts showed increased survival and only mild immunoreactivity in vivo compared with suspended midbrain dopaminergic progenitor cell grafts.Overall,our findings show that these midbrain dopaminergic progenitor cell beads enhance the effectiveness of neuronal cell transplantation.

关键词： axonal integrity cell cryopreservation cellular environment cellular niche cell replacement therapy dopaminergic progenitors human pluripotent stem cell mechanical damage neuronal cell delivery Parkinson’s disease small-aperture gelatin microcarriers

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intracellular redox potential-driven live-cell synthesis of CdSe quantum dots in Staphylococcus aureus

引用

Science China Chemistry 2024年第3期67卷 990-999页

作者： Cai-Qin Wu An-An Liu Xu Li Jia-Wei Tu Juan Kong Ling-Ling Yang Jian-Hong Jia Chuan Wang Bin Hu Zhi-Xiong Xie Dai-Wen Pang The institute for Advanced Studies College of Chemistry and Molecular SciencesCollege of Life SciencesHubei Key Laboratory of Cell HomeostasisWuhan UniversityWuhan 430072China Research Center for Analytical Sciences College of ChemistryState Key Laboratory of Medicinal Chemical BiologyTianjin Key Laboratory of Biosensing and Molecular RecognitionFrontiers Science Center for New Organic MatterFrontiers Science Center for Cell Responsesand Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China

Biosynthesized semiconductor quantum dots(QDs) have bright fluorescence,adjustable particle sizes,and environmental friendliness,endowing them with convenience and potential for biological applications.Due to the unclear mechanism of the cellular environment on the live-cell synthesis of QDs,it is still difficult to regulate their optical properties.Here,the critical role of the intracellular redox environment in regulating the fluorescence properties of biosynthesized CdSe QDs in Staphylococcus aureus(S.aureus) has been elucidated.The glutathione peroxidase(GPx) activity directly affects the intracellular H_(2)O_(2) produced in the SeO_(3)^(2-) reduction,which further manipulates the glutathione redox cycle to determine the content of low-valence Seintermediates.As a result,the fluorescence intensity of the synthesized CdSe QDs increases by 60% in the GPx overexpressed cells.The cellular redox potential that is controlled by the GSH redox cycle provides the driving force for the reduction of SeO_(3)^(2-),facilitating the synthesis of CdSe QDs in S.aureus cells.The proposed mechanism of the cellular redox state provides a new perspective for regulating the synthesis of semiconductor nanomaterials in live cells.

关键词： redox H_(2)O_(2) peroxidase quantum dot Staphylococcus aureus

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of trace oxygen on plasma nitriding of titanium foil

引用

Chinese Physics B 2024年第6期33卷 548-551页

作者：周海涛熊希雅马可欣罗炳威罗飞申承民 Beijing institute of Aeronautical Materials Aero Engine Corporation of ChinaBeijing 100095China Beijing National Laboratory of Condensed matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Titanium nitride films are prepared by plasma enhanced chemical vapor deposition method on titanium foil using N_(2) as precursor. In order to evaluate the effect of oxygen on the growth of titanium nitride films, a small amount of O_(2) is introduced into the preparation process. The study indicates that trace O_(2) addition into the reaction chamber gives rise to significant changes on the color and micro-morphology of the foil, featuring dense and long nano-wires. The as-synthesized nanostructures are characterized by various methods and identified as TiN, Ti_(2) N, and TiO_(2) respectively. Moreover, the experiment results show that oxide nanowire has a high degree of crystallinity and the nitrides present specific orientation relationships with the titanium matrix.

关键词： nitride oxide nanostructure crystalline plasma-enhanced chemical vapor deposition system(PECVD)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Saturable absorption and visible pulse modulation of few-layer topological nodal-line semimetal HfGeTe

引用

Chinese Optics Letters 2024年第3期22卷 89-94页

作者：赵启明张首焱王树贤王刚于浩海张怀金 State Key Laboratory of Crystal Materials and institute of Crystal Materials Shandong UniversityJinan 250100China Beijing National Laboratory for Condensed matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Topological nodal-line semimetals attract growing research attention in the photonic and optoelectronic fields due to their unique topological energy-level bands and fascinating nonlinear optical responses.Here,to the best of our knowledge,we first report the saturable absorption property of topological nodal-line semimetal HfGeTe and the related pulse modulation in passively Q-switched visible lasers.Few-layer HfGeTe demonstrates outstanding saturable absorption properties in the visible-light band,yielding the saturation intensities of 7.88,12.66,and 6.64μJ/cm^(2)at 515,640,and 720 nm,respectively.Based on an as-prepared few-layer HfGeTe optical switch and a Pr:LiYF_(4)gain medium,Q-switched visible lasers are also successfully achieved at 522,640,and 720 nm.The minimum pulse widths of the green,red,and deep-red pulsed lasers are150,125.5,and 420 ns,respectively.Especially for the green and red pulsed laser,the obtained pulse width is smaller than those of the low-dimensional layered materials.Our work sheds light on the application potential of topological nodal-line semimetals in the generation of visible pulsed lasers.

关键词： visible pulsed laser topological nodal-line semimetals saturable absorption Q-switching Pr doping

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：