检索结果-南通市图书馆

Parents making surgical decisions for their children:a pilot study

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

World Journal of Pediatric Surgery 2023年第2期6卷 115-117页

作者： Adrian Chi Heng Fung Kenneth Kak Yuen Wong Department of Surgery The University of Hong KongHong KongChina

Parents play a key role in medical decision-making for their children,who are limited by their intellectual development in under-standing their own health status and treat-ment plans.1 These decisions are challenging as they may have a lifelong impact on patients'physical and mental well-being,and a signif-icant portion of parents are not satisfied with the informed consent process.Various factors affecting parental satisfaction with the informed consent process have been identi-fied,including parents'knowledge base,the specific types of decisions and the presence of decisional conflicts.

关键词： children their parents

Enhanced cortical bone expansion in Lgals3-deficient mice during aging

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

Bone Research 2018年第1期6卷 95-106页

作者： Kevin A.Maupin Kevin Weaver Alexis Bergsma Cheryl Christie Zhendong A.Zhong Tao Yang Bart O.Williams Center for Cancer and Cell Biology Program for Skeletal Disease and Tumor Microenvironment Van Andel Research Institute

Imbalances between bone formation and bone resorption, which can occur due to aging or sex hormone deprivation, result in decreased bone mass and an increased risk of fracture. Previous studies have suggested that the β-galactoside binding lectin,galectin-3, is involved in bone remodeling. We compared bone parameters of mice having null alleles of the galectin-3 gene(Lgals3-KO) with those of their wild-type littermates. Lgals3 deficiency increased cortical bone expansion at 36 weeks(wk) and preserved or enhanced bone mass in both male and female mutant mice. In addition, female Lgals3-KO mice were protected from age-related loss of trabecular bone. Histomorphometry and ex vivo primary cell differentiation assays showed increased osteoblastogenesis with little-to-no effect on osteoclastogenesis, suggesting the increased bone mass phenotype is primarily due to increased anabolism. Our study identifies galectin-3 as a negative regulator of bone formation and suggests that disruption of galectin-3 may be useful in preventing bone loss during aging.

关键词： Lgals3-KO their wild-type Histomorphometry

The structure of the human 4F2hc-LAT1 heteromeric amino acid transporter

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2019年第6期62卷 848-850页

作者： Dimitrios Fotiadis Jean-Marc Jeckelmann Institute of Biochemistry and Molecular Medicine and Swiss National Centre of Competence in Research (NCCR) TransCureUniversity of Bern

Amino acids are biologically important molecules that serve as energy source, building blocks of proteins, precursors for metabolites and signaling compounds in all living cells.Transport of proteinogenic amino acids and related substances across biological membranes is mediated by membrane embedded proteins:the amino acid transporters. These membrane proteins belong to different solute carrier (SLC)families (http://***) and transfer amino acids in and out between compartments inside cells, between different cells and between organs. Amino acid transporters have diverse important physiological functions and their absence, overexpression and malfunction can lead to human diseases.

关键词： Amino acids important molecules functions and their absence

Mechanical Models,Structures,and Applications of Shape-Memory Polymers and their Composites

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2019年第5期32卷 535-565页

作者： Xiaozhou Xin Liwu Liu Yanju Liu Jinsong Leng Department of Astronautical Science and Mechanics Harbin Institute of Technology(HIT)P.O.Box 301No.92 West Dazhi StreetHarbin 150001China Centre for Composite Materials Harbin Institute of Technology(HIT)P.O.Box 3011No.2 Yikuang StreetHarbin 150080China

Shape-memory polymers(SMPs)and their composite materials are stimuliresponsive materials that have the unique characteristics of lightweight,large deformation,variable stiffness,and biocompatibility.This paper reviews the research status of the mechanical models for SMPs,shape-memory nanocomposites and shape-memory polymer composites(SMPCs);it also introduces some spatially deployable structures,such as hinges,beams,and antennae based on SMPCs.In addition,the deformation types of 4D printing structures and the potential applications of this technology in robots and medical devices are also summarized.

关键词： Shape-memory polymers and their composites Constitutive model Deployable st rue tu re 4D printing

Multiply Charged Anions,Maximum Charge Acceptance,and Higher Electron Affinities of Molecules,Superatoms,and Clusters

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

物理化学学报 2018年第6期34卷 675-682页

作者： VON SZENTPáLY László Institut fur Theoretische Chemie Universitat Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany.

The addition of electrons to form gas-phase multiply charged anions(MCAs)normally requires sophisticated experiments or calculations.In this work,the factors stabilizing the MCAs,the maximum electron uptake of gas-phase molecules,X,and the electronic stability of MCAs X^(Q-),are discussed.The drawbacks encountered when applying computational and/or conceptual density functional theory(DFT)to MCAs are highlighted.We develop and test a different model based on the valence-state concept.As in DFT,the electronic energy,E(N,v_(ex)),is a continuous function of the average electron number,N,and the external potential,v_(ex),of the nuclei.The valence-state-parabola is a second-order polynomial that allows extending E(N,v_(ex))to dianions and higher MCAs.The model expresses the maximum electron acceptance,Q_(max),and the higher electron affinities,A_Q,as simple functions of the firstelectron affinity,A_1,and the ionization energy,I,of the"ancestor"system.Thus,the maximum electron acceptance is Q_(max,calc)=1+12A_1/7(I-A_1).The ground-state parabola model of the conceptual DFT yields approximately half of this value,and it is termed Q_(max,GS)=?+A_1/(I-A_1).A large variety of molecules are evaluated including fullerenes,metal clusters,super-pnictogens,super-halogens(OF_3),super-alkali species(OLi_3),and neutral or charged transition-metal complexes,AB_(m )L_n^(0/+/-).The calculated second electron affinity A_(2,calc)=A_1-(7/12)(I-A_1)is linearly correlated to the literature references A_(2,lit) with a correlation coefficient R=0.998.A_2 or A_3 values are predicted for further 24 species.The appearance sizes,n_(ap)^(3-),of triply charged anionic clusters and fullerenes are calculated in agreement with the literature.

关键词： Multiply charged negative ions their appearance sizes Second electron affinity Third electronaffinity Conceptual density-functional theory Valence-state parabola model of electronegativity

Valence electronic structure of tantalum carbide and nitride

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 737-741页

作者： FAN ChangZeng1,2,SUN LiLing2,WEI ZunJie1,MA MingZhen3,LIU RiPing3,ZENG SongYan1 & WANG WenKui3 1 Department of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China 2 National Laboratory for Superconductivity,Institute of Physics,Chinese Academy of Sciences,Beijing 100080,China 3 National Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qin-huangdao 066004,China Department of Materials Science and Engineering Harbin Institute of Technology Harbin China National Laboratory for Superconductivity Institute of Physics Chinese Academy of Sciences Beijing China National Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao China

The valence electronic structures of tantalum carbide (TaC) and tantalum nitride (TaN) are studied by using the empirical electronic theory (EET). The results reveal that the bonds of these compounds have covalent,metallic and ionic characters. For a quantitative analysis of the relative strength of these components,their ionicities have been calculated by implanting the results of EET to the PVL model. It has been found that the ionicity of tantalum carbide is smaller than that of tantalum nitride. The EET results also reveal that the covalent electronic number of the strongest bond in the former is larger than that of the latter. All these suggest that the covalent bond of TaC is stronger than that of TaN,which coincides to that de-duced from the first-principles method.

关键词： TaC, TaN, valence electronic structure, ionicity The valence electronic structures of tantalum carbide (TaC) and tantalum nitride (TaN) are studied by using the empirical electronic theory (EET). The results reveal that the bonds of these compounds have covalent, metallic and ionic characters. For a quantitative analysis of the relative strength of these components, their ionicities have been calculated by implanting the results of EET to the PVL model. It has been found that the ionicity of tantalum carbide is smaller than that of tantalum nitride. The EET results also reveal that the covalent electronic number of the strongest bond in the former is larger than that of the latter. All these suggest that the covalent bond of TaC is stronger than that of TaN, which coincides to that deduced from the first-principles method.……

Numerical investigation on detonation cell evolution in a channel with area-changing cross section

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 797-808页

作者： DENG Bo,HU ZongMin,TENG HongHui & JIANG ZongLin Key Laboratory of High Temperature Gas Dynamics,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100080,China Key Laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences Beijing China

The two-dimensional cellular detonation propagating in a channel with area-changing cross section was numerically simulated with the dispersion-controlled dissipative scheme and a detailed chemical reaction model. Effects of the flow ex-pansion and compression on the cellular detonation cell were investigated to illus-trate the mechanism of the transverse wave development and the cellular detona-tion cell evolution. By examining gas composition variations behind the leading shock,the chemical reaction rate,the reaction zone length,and thermodynamic parameters,two kinds of the abnormal detonation waves were identified. To explore their development mechanism,chemical reactions,reflected shocks and rarefac-tion waves were discussed,which interact with each other and affect the cellular detonation in different ways.

关键词： detonation cells, transverse waves, detailed chemical reaction model, numerical simulation The two-dimensional cellular detonation propagating in a channel with area- changing cross section was numerically simulated with the dispersion-controlled dissipative scheme and a detailed chemical reaction model. Effects of the flow expansion and compression on the cellular detonation cell were investigated to illustrate the mechanism of the transverse wave development and the cellular detonation cell evolution. By examining gas composition variations behind the leading shock, the chemical reaction rate, the reaction zone length, and thermodynamic parameters, two kinds of the abnormal detonation waves were identified. To explore their development mechanism, chemical reactions, reflected shocks and rarefaction waves were discussed, which interact with each other and affect the cellular detonation in different ways. ……

Study　of　Binary　Rare－Earth　Oxyfluoride　for　ODE　Reaction　and　their　XRD　＆In－Situ　Raman　Characterization

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1996年第10期7卷 954-955页

作者： Ji Zhong LUO Xiao Ping ZHOU Zi Sheng CHAO Hu Lin WAN(Department of Chemistry & State Key Laboratory for Physical Chemistry of the Solid Surface,Xiamen University, Xiamen 361005) Department of Chemistry State Key Lab. Phys. Chem. Solid S. Xiamen University Xiamen 361005

A series of new binary rare earth oxyfluoride (Sm2O3-LaF3) catalysts have been developed for ODE reaction. High C2H4 selectivity(91.5%) with C2H6 conversion 21.7% was achieved on the catalyst Sm2O3/LaF3 with molar ratio 1/1 at 700℃. The addition of 16.7 mol% BaF2 into Sm2O3/LaF3(1/1 in mol) led to the increase of C2H6 conversion from 21.7% to 40.8%,however. the change of ethene seletivity was not apparent (from 91.5% to 88.0%).

关键词： ODE Reaction Oxyfluoride their XRD

The self-aggregation of chiral threonine-linked porphyrins and their zinc( II) complexes

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2000年第5期45卷 418-421页

作者： Xiaobin Peng Jinwang Huang Liangnian Ji Zhongshan Univ Coll Chem & Chem Engn Guangzhou 510275 Peoples R China

The self-aggregation of chiral threonine-linked porphyrins and their zinc(Ⅱ) complexes in water-alcohol system and water-alcohol-NaCI system has been studied by circular dichroism (CD), UV-Vis absorption spectra and fluorescence spectra methods. The experiment results indicate that chiral threonine-linked porphyrins and their zinc(Ⅱ) complexes have two different kinds of aggregates in water-alcohol system and water-alcohol-NaCI system. And the porphyrins may form highly organized and orientated aggregates in water-alcohol-NaCI system. The aggregates in water-alcohol-NaCI system may have helical structures.

关键词： threonine-linked porphyrins and their zinc( Ⅱ) complexes aggregation.