检索结果-南通市图书馆

Investigations of nuclear Chirality at iThemba LABS

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第2期19卷 7-38页

作者： R.A.Bark E.A.Lawrie C.Liu S.Y.Wang iThemba Laboratory for Accelerator Based Sciences National Research FoundationP.O.Box 722Somerset-West 7129South Africa Department of Physics University of the Western CapePrivate Bag X177535BellvilleSouth Africa Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209China

Progress in the studies of Chirality in atomic nuclei at iThemba LABS is reviewed.New regions of Chirality,around mass 80 and 190 have been discovered using the AFRODITE array,specifically in the nuclei^(74)As,^(78,80,82)Br,^(81)Kr,and^(193,194,198)Tl.Many phenomena have been observed,including multiple chiral bands in the same nucleus,the coexistence of octupole correlations and nuclear Chirality,and the coexistence of pseudo spin and nuclear Chirality.The best example of chiral degeneracy to date was found in ^(194)Tl.The level scheme of ^(106)Ag has been revisited and interpreted in terms of two-and four-quasiparticle bands.Investigations using the particle-rotor model have shown that the fingerprints of Chirality in the two-quasiparticle system only can occur in an idealised model description.For systems with a higher number of quasiparticles,the calculations showed that nuclear Chirality can persist.

关键词： Chirality high-spin states particle-rotor model

Remarkable difference of phospholipid molecular Chirality in regulating PrP aggregation and cell responses

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

中国化学快报：英文版 2023年第2期34卷 236-243页

作者： Cunli Wang Xue Wang Dongdong Wang Shengxu Qian Fusheng Zhang Mingyang Li Minmin Li Wenqi Lu Bo Liu Guangyan Qing School of Biomedical Engineering Dalian University of TechnologyDalian 116024China CAS Key Laboratory of Separation Science for Analytical Chemistry Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China College of Chemistry and Chemical Engineering Wuhan Textile UniversityWuhan 430200China

Prion diseases are fatal neurodegenerative diseases that can cause severe dementia.The misfolding and accumulation of the prion peptide (PrP)_(106–126) is crucial,and this process is closely relevant to biological membranes.However,how PrP_(106–126)aggregation is affected by the molecular Chirality of phospholipid membrane is unknown.Thus,in this study,a pair of L-and D-aspartic acid (Asp)-modified 1,2-dipalmitoyl-sn–glycero-3-phosphoethanolamine (DPPE) were synthesized to construct chiral liposomes.We discover that L-Asp-DPPE liposomes strongly inhibit the oligomerization and amyloidogenesis of PrP_(106–126),whether acting on monomers or oligomers,which rescues cytotoxicity induced by PrP_(106–126).By comparison,D-Asp-DPPE liposomes inhibit peptide oligomerization only at a high concentration and cannot prevent amyloidogenesis when acting on oligomers,which lead to pronounced cytotoxicity.Apoptosis experiment,dynamic change of intracellular Ca^(2+)(_(i)Ca^(2+)) and Ca^(2+)release from endoplasmic reticulum(ER),reactive oxygen species (ROS) production,adsorption dynamics and affinity tests,and fluorescent imaging clearly disclose that molecular Chirality of the liposomes dominates conformational transition of PrP_(106–126)from random coil to β-sheet,binding and adsorption of the monomers and oligomers,and subsequent fibrillation process,resulting in distinct inhibition effect in Ca^(2+)overload and release,ROS production and cell apoptosis.This work is the first to report that interfacial molecular Chirality is a potentially crucial influence on the fibrillation process of PrP_(106–126) and its cell responses,whereas the convergence of chiral amino acids and liposomes can be considered potential inhibitors in prion diseases.

关键词： Prion disease Liposome Chirality Interface Cytosolic Ca^(2+)

Electrically driven motion, destruction, and Chirality change of polar vortices in oxide superlattices

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2022年第3期65卷 77-84页

作者： Pan Chen Congbing Tan Zhexin Jiang Peng Gao Yuanwei Sun Lifen Wang Xiaomei Li Ruixue Zhu Lei Liao Xu Hou Ke Qu Ning Li Xiaomin Li Zhi Xu Kaihui Liu Wenlong Wang Jinbin Wang Xiaoping Ouyang Xiangli Zhong Jie Wang Xuedong Bai Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China International Center for Quantum Materials Electron Microscopy LaboratorySchool of PhysicsPeking UniversityBeijing 100871China Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials School of Physics and ElectronicsHunan University of Science and TechnologyXiangtan 411201China Department of Engineering Mechanics Zhejiang UniversityHangzhou 310027China Collaborative Innovation Center of Quantum Matter Beijing 100871China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China State Key Laboratory for Artificial Microstructure&Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang UniversityHangzhou 310027China

Topological polar vortices, which are electric analogs of magnetic objects, present great potential in applications of future nanoelectronics because of their nanometer size, anomalous dielectric response, and Chirality. To enable the functionalities, it is prerequisite to manipulate the polar states and Chirality by using external stimuli. Here, we probe the evolutions of polar state and Chirality evolutions of topological polar vortices in Pb TiO;/Sr TiO;superlattices under an electric field by using atomically resolved in situ scanning transmission electron microscopy and phase-field simulations. We find that, under electric field, the chiral vortex cores can be moved laterally to form close-pair structures, transform into a/c domain stripes, and finally become a nonchiral c-domain. Such transition is reversible and spontaneous after bias removal. Interestingly, during switching and backswitching events, the vortex rotation can be changed, offering a potential strategy to manipulate vortex Chirality. The revealed dynamic behavior of individual polar vortices at the atomic scale provides fundamentals for future device applications.

关键词： Chirality polar vortex ferroelectrics in situ transmission electron microscopy phase-field simulations

Chiral Macrocyclic AIEgens from BINOL and Tetraphenylethene via Tailoring Chirality of Luminescent Molecular Propellers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2022年第20期40卷 2393-2399页

作者： Yitong Wang Xiaoqing Liu Hongkun Li Xindong Liu Lei Wang Yi Liu Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhenGuangdong518060 China Institute of Critical Materials for Integrated Circuits Shenzhen PolytechnicShenzhenGuangdong518055 China State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials College of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu215123 China Centre for AIE Research Shenzhen UniversityShenzhenGuangdong518060 China

Herein,a pair of chiral macrocyclic luminogens derived from chiral 1,1-bi(2-naphthol)(BINOL)and tetraphenylethenes(TPEs)have been prepared with high yield via intramolecular McMurry coupling,in which the preferential helicity of propeller-shaped TPE units can be tuned via choosing proper chiral BINOL tethers.The preferential chiral geometry of the macrocyclic luminogen was unambiguously confirmed by X-ray crystal crystallography and theoretical calculation,whereas the variable-temperature NMR spectra and chiral HPLC analysis further verified the intramolecular motions.These two chiral macrocyclic luminogens both exhibit obvious aggregation-induced emission behavior and mechanochromic luminescence properties.Furthermore,aggregation attenuated CD signals and circularly polarized luminescence were observed for these two chiral macrocylic luminogens in THF-water mixture and PMMA matrix.These results had paved a new approach toward constructing chiral aggregation-induced emission luminogens(AIEgens)and their structural engineering.

关键词： Aggregation-induced emission Chirality Macrocycles Circularly polarized luminescence Luminescence

Simultaneous enhancement of phosphorescence and Chirality by host–guest recognition of molecular tweezers

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

Chinese Chemical Letters 2022年第11期33卷 4900-4903页

作者： Diankun Jia Hua Zhong Sixun Jiang Risheng Yao Feng Wang School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China School of Food and Biological Engineering Hefei University of TechnologyHefei 230009China CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

A novel type of host-guest recognition systems have been developed on the basis of a Au(Ⅲ) molecular tweezer receptor and chiral Pt(Ⅱ) guests. The complementary host-guest motifs display high non-covalent binding affinity (Ka: ∼10^(4) L/mol) due to the participation of two-fold intermolecular π-π stacking interactions. Both phosphorescence and Chirality signals of the Pt(Ⅱ) guests strengthen in the resulting host-guest complexes, because of the cooperative rigidifying and shielding effects rendered by the tweezer receptor. Their intensities can be reversibly switched toward pH changes, by taking advantage of the electronic repulsion effect between the protonated form of tweezer receptor and the positive-charged guests in acidic environments. Overall, the current study demonstrates the feasibility to enhance and modulate phosphorescence and Chirality signals simultaneously via molecular tweezer-based host-guest recognition.

关键词： Host-guest chemistry Molecular tweezer Room-temperature phosphorescence Chirality Stimuli-responsiveness

Chirality and chiral functional composites of bicontinuous cubic nanostructured cubosomes

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第3期33卷 1488-1492页

作者： Deyin Wang Hongkai Liu Wei Wang Center for Synthetic Soft Materials Key Laboratory of Functional Polymer Materials of Ministry of Education and Institute of Polymer ChemistryCollege of ChemistryNankai UniversityTianjin 300071China

Molecular self-assembly is the most important strategy for the development of chiral aggregates and chiral functional materials. In this study, we rationally designed and synthesized chiral fluorescent heteroclusters that were self-assembled into microscale cubosomes with a three-dimensional(3D) bicontinuous cubic phase nanostructure. The cubosomes exhibited Chirality, indicating that Chirality is transferred from the molecules to the 3D nanostructure. Therefore, we confirmed the formation of a chiral bicontinuous cubic phase nanostructure for the first time. We also showed that this Chirality originates from the continuous change in the saddle-splay distortion of the molecules within the curved bilayer. At the same time, transparent films of chiral composites were prepared by mixing the chiral cubosomes with an epoxy resin and then curing the mixture. Therefore, we demonstrated an effective method for preparing chiral composites.

关键词： Chirality Self-assembly Nanostructure Composite

Influence of residual Chirality on the conformation and enzymatic degradation of glycopolypeptide based biomaterials

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第3期64卷 641-650页

作者： SHI Shun WANG JiaYu WANG TianRan REN Hui ZHOU YuHao LI Gao HE ChaoLiang CHEN XueSi CAS Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China College of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Jilin Biomedical Polymers Engineering Laboratory Changchun 130022China

Glycopolypeptides as analogs of glycoproteins or glycosaminoglycans represent attractive building blocks for the construction of biomimetic biomaterials.However,the effects of amino acid Chirality on the conformation and enzymatic degradation of glycopolypeptides are often overlooked.Here,we synthesized and characterized a range of glycopolypeptides composed of galactosylated poly(γ-propargylglutamate)s containing L-and/or D-glutamate residues.Glycopolypeptides containing pure Lglutamate residues were predominantlyα-helical,and the helicity increased over the degree of polymerization of the polypeptide backbones(24 to 44).The glycopolypeptide with pure D-glutamate residues adopted a mirroredα-helical conformation,whilst apparent random coil conformation was observed for the glycopolypeptide with equally mixed enantiomeric residues.The enzymatic degradation rates of the glycopolypeptides were markedly reduced following the introduction of D-glutamate residues into backbones.Galactoside pendants on these glycopolypeptides maintained their binding to peanut agglutinin.These structureproperty relationships provide new insight for the design of biomimetic biomaterials containing glycopolypeptides.

关键词： glycopolypeptides secondary structures enzymatic degradation Chirality lectin binding

Helical secondary structures and supramolecular tilted Chirality in N-terminal aryl amino acids with diversified optical activities

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第4期32卷 1390-1396页

作者： Zhuoer Wang Aiyou Hao Pengyao Xing School of Chemistry and Chemical Engineering Shandong UniversityJi'nan 250100China

Helix structures at atomic/molecular level have not been found in self-assembled peptide seque nce with less than three residues.Asβ-sheet supramolecular secondary structures have been discovered in solidstate amino acids,we here report the conjugation of simple N-terminal aryl protecting group could give rise to helical supramolecular secondary structures in solid-state,which determines the optical activities of the adjacent aryl groups.The carboxylic acid-involved asymmetric H-bonds in N-te rminal aryl amino acids induce the emergence of super-helical structures of amino acid residues and aryl groups.In most cases,supramolecular tilted Chirality of aryl groups is opposite to that of amino acid sequences,of which handedness and helical pitch are determined by the H-bond modalities.Determining correlation between supramolecular tilted Chirality of aryl segments and their chiroptical activities is firstly unveiled,which was verified by the computational results based on density functional theory.Most aryl amino acids self-assembled by nanoprecipitation method via crystallization induced self-assembly into rigid one-dimensional microstructures with ultra-high Young's modulus.This study reveals the generic existence of chiral supramolecular structure s in aggregated amino acid derivatives and gives an in-depth investigation into the structural-property relationships,which could guide the rational design and screening of chiroptical supramolecular materials.

关键词： Amino acids Self-assembly Chirality Chiroptical properties H-bonds

Thiophene and naphthalene-based double helix:Synthesis,structures and Chirality

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第1期32卷 457-460页

作者： Chunmei Zhao Zhiying Ma Chunli Li Li Xu Hua Wang Engineering Research Center for Nanomaterials Henan UniversityKaifeng 475004China School of Chemical Engineering and Food Science Zhengzhou Institute of TechnologyZhengzhou 450044.China College of Chemistry and Chemical Engineering Henan UniversityKaifeng 475004China

Both racemate and enantiomer of a novel double helix,binaphthylcyclooctaterthiophene(BN-COTh),which is a DNA-like molecule constructed by two single helices intertwined with each other via covalent bonds,have been synthesized with two building blocks,cycloocta-tetrathiophene(COTh) and cyclooctadinaphthyldithiophene(CONT) fused together via Negishi coupling reaction.Another homologue,dinaphthylcyclooctaterthiophene(DN-COTh) has been employed together as a model compound.Besides the synthetic work,BN-COTh and DN-COTh have been investigated by studying their crystal structures,spectroscopic behaviors,chiral resolution and chiral characteristics,including circular dichroism(CD) spectra and optical rotations.In addition,the novel crystal of enantiomer of(R,R,R)-BN-COTh has been explored.The enantiomer molecules packing along b-axis to form a larger and extended assembly packing due to intermolecular interactions between the enantiomer molecules and chloroform molecules in crystal.

关键词： Binaphthylcyclooctaterthiophene Dinaphthylcyclooctaterthiophene Double helix Crystal structure Chirality