检索结果-南通市图书馆

Antitumoral activity of low density lipoprotein-aclacinomycin complex in mice bearing H_(22) tumor

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2000年第1期6卷 140-142页

作者： Bi WX xu SD Zhang PH Kong f Department of Biochemistry Shandong Medical UniversityJinan250012Shandong ProvinceChina Department of Gynaecology and Obstetrics First Affiliated Hospital of Shandong Medical UniversityJinan 250012Shandong ProvinceChina Department of Biochemistry Shandong Medical UniversityJinan 250012Shandong ProvinceChina

INTRODUCTIONCancer cells,which proliferate rapidly need largeamounts of cholesterol for new membrane synthesis,and high LDL receptor (LDLR) *** hasbeen proposed as a useful discriminatory vehicle forthe delivery of cy... 详细信息

关键词： Subject headings hepatoma cells lipoprotein low density aclacinomycin LDL receptor mice

A SMALLEST SINGULAR VALUE METHOD fOR SOLVING INVERSE EIGENVALUE PROBLEMS

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

Journal of Computational Mathematics 1996年第1期14卷 23-31页

作者： S.f. xu(Department of Mathematics, Peking University, Beijing) BEIJING UNIV DEPT MATHBEIJING 100871PEOPLES R CHINA

Utilizing the properties of the smallest singular value of a matrix, we propose a new, efficient and reliable algorithm for solving nonsymmetric matrix inverse eigenvalue problems, and compare it with a known method. ... 详细信息

关键词： Math A SMALLEST SINGULAR VALUE METHOD fOR SOLVING INVERSE EIGENVALUE PROBLEMS

The Impacts of a Teaching Personal and Social Responsibility Intervention on Social and Emotional Competence in Physical Education: A Quasi-Experimental Study

在线全文

学校读者我要写书评

暂无评论

International Journal of Mental Health Promotion 2025年第2期27卷 161-177页

作者： Weidong Li Zh Yeng Chong Yaqing Mao Wanying Zhang Wei xu Mingwei Li Yiyun Wang Huaxia Xiong College of Education for the future Beijing Normal University at Zhuhai Zhuhai 519087 China School of General Education Beijing Normal University-Hong Kong Baptist University United International College Zhuhai 519087 China faculty of Psychology Beijing Normal University Beijing 100875 China faculty of Education Beijing Normal University Beijing 100875 China faculty of Preschool Education Beijing Institute of Education Beijing 100120 China Mental Health Center Hebei University of Economics and Business Shijiazhuang 050061 China

Background: The Teaching Personal and Social Responsibility (TPSR) model in physical education (PE) has been shown to promote Social and emotional competence (SEC). However, the underlying mechanisms through which TPSR enhances SEC, particularly in university students within the Chinese context, remain unclear. This study aims to explore the effects of TPSR and the mediating roles of self-efficacy and grit in improving SEC. Methods: 71 Chinese university students were in the TPSR group, and 39 in the Traditional Teaching Model (TTM) control group, assessed before and after a 14-week intervention. The Adapted Social and Emotional Competence Scale (ASECS), General Self-Efficacy Scale (GSES), and Short Grit Scale (SGS) were used for measurement. A mixed-design ANOVA assessed TPSR’s effects, with post-hoc t -tests for pre-post differences and mediation analysis for underlying mechanisms. Results: The mixed-design ANOVA revealed a significant interaction between time and intervention on SEC. The TPSR group showed significant improvement from pre-test to post-test ( t (70) = −2.63, p = 0.011, Cohen’s d = −0.31), whereas the TTM control group did not ( t (38) = 1.40, p = 0.170, Cohen’s d = 0.22). The TPSR group also showed a significant increase in self-efficacy ( t (70) = −3.67, p ficant effects were found for grit ( f = 0.342, p = 0.560). Mediation analysis confirmed that self-efficacy significantly mediated the effects of the TPSR intervention on SEC (95% CI: 0.0277 to 0.2897). Conclusion: The TPSR intervention led to significant improvements in university students’ SEC and self-efficacy, with no significant changes observed in grit. Self-efficacy served as a mediator in the relationship between the intervention and SEC.

关键词： Grit mediation social and emotional competence self-efficacy TPSR physical education

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

宣木瓜抗炎活性与成分

食品与发酵工业 2025年第3期51卷 250-256页

作者：周勤纯徐德平江南大学食品学院江苏无锡214000

探究宣木瓜抗炎活性成分及其化学结构。以宣木瓜为原料,进行醇提、水提醇沉得到不同提取物,利用二甲苯诱导的小鼠耳肿胀模型测定其抗炎活性。醇提物经MCI层析柱、SephadexLX-20层析柱、ODS-AQ柱分离得到一个活性组分N,水提醇沉物经DEAE... 详细信息

探究宣木瓜抗炎活性成分及其化学结构。以宣木瓜为原料,进行醇提、水提醇沉得到不同提取物,利用二甲苯诱导的小鼠耳肿胀模型测定其抗炎活性。醇提物经MCI层析柱、SephadexLX-20层析柱、ODS-AQ柱分离得到一个活性组分N,水提醇沉物经DEAE-纤维素柱、HW-55f凝胶柱和SephacryI S-400分离得到活性多糖PCC-1,采用小鼠耳肿胀模型结合小鼠血清炎症因子水平对抗炎活性进一步评价。结果表明,组分N和多糖PCC-1均有抗炎活性,并确定多糖PCC-1是主要功效成分,组分N只是辅助。通过核磁共振鉴定,组分N为二聚体原花青素,首次从木瓜中分离得到;多糖PCC-1由葡萄糖和葡萄糖醛酸组成,主链以β1→4键相连,主链上的C 3,C 2位有侧链相连,一部分C 6位形成糖醛酸,一部分C 6位被甲酯化。该多糖的糖醛酸结构在抗炎机制中发挥着关键作用。

关键词：宣木瓜原花青素多糖抗炎分离鉴定

多光谱法研究二氢杨梅素对胰脂肪酶的抑制作用

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2025年第1期45卷 107-116页

作者：孟晓慧黄旭波夏张晨徐娟王衍彬程俊文杨柳贺亮浙江省森林资源生物与化学利用重点实验室浙江省林业科学研究院浙江杭州310023 浙江省特色中药资源保护与创新利用重点实验室浙江农林大学食品与健康学院浙江杭州311300

藤茶中主要黄酮类物质——二氢杨梅素(DMY)具有多种生物活性,而其降血脂机理鲜有报道。采用紫外光谱研究了DMY对胰脂肪酶(PL)的抑制作用,结合荧光光谱、同步荧光光谱、三维荧光光谱及分子对接模拟法研究了二者之间的相互作用及机理。紫... 详细信息

藤茶中主要黄酮类物质——二氢杨梅素(DMY)具有多种生物活性,而其降血脂机理鲜有报道。采用紫外光谱研究了DMY对胰脂肪酶(PL)的抑制作用,结合荧光光谱、同步荧光光谱、三维荧光光谱及分子对接模拟法研究了二者之间的相互作用及机理。紫外光谱测得DMY对PL的半抑制浓度为2.6×10^(-4)mol·L^(-1),表明其对PL具有较好的抑制作用,采用Lineweaver-Burk方程得出该抑制剂为竞争性作用,其抑制常数为6×10^(-4)mol·L^(-1);通过Stern-Volmer方程和静态猝灭双对数公式对293和310 K两者互作的荧光光谱计算,结果表明DMY能猝灭PL的自发荧光,荧光猝灭方式为静态猝灭,猝灭常数K_(SV)与温度负相关;结合常数K a与温度正相关,结合位点数n约为1,说明DMY与PL结合并形成稳定的配位复合物;采用Van't Hoff方程求出结合过程中的热力学参数ΔS=0.2014 J·mol^(-1)·K^(-1),ΔH=32.311 kJ·mol^(-1),ΔG小于0,表明两者通过疏水作用力自发结合且放热;由f rster非辐射能量转移理论计算出结合距离r=1.475 nm,说明DMY与PL结合生成复合物时发生了非辐射能量转移;同步荧光光谱结果表明,DMY与PL的相互作用对PL的二级构象发生了明显改变,主要作用于色氨酸(Tyr)附近。紫外光谱进一步揭示DMY可使PL发生π→π跃迁,导致其氨基酸残基的微环境变化;三维荧光光谱显示DMY可使PL两个特征峰(peak1,peak2)分别红移10和5 nm,荧光强度分别下降51.38%和41.93%,证实两者发生疏水作用后PL的微环境极性增大,构象改变;分子对接模拟结果表明,DMY结合位点位于PL中由PHE77、PHE215、TYR114、ILE209、PRO180氨基酸形成的疏水口袋内,其A环C5、B环C4′、C环C3、C环C O的-OH分别与氨基酸HIS263、TYR114、SER152、PHE215形成氢键,与氨基酸LRU213、GLU179、ALA178、THR78产生范德华力。实验数据有助于深入解DMY的降血脂分子作用机制,其独特的结构为天然抑制剂的药物合成和筛选提供了理论依据。

关键词：二氢杨梅素胰脂肪酶多光谱法分子对接模拟

HIGHLY DISPERSED MULTI-WALLED CARBON NANOTUBES IN WATER/ETHANOL AND ITS APPLICATION fOR PVA COMPOSITE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 389-396页

作者： X.Y.Tao J.M.xu f.Liu G.L.xu InstituteofMaterialsPhysicsandMicrostructures DepartmentofMaterialsScienceandEngmeeringZhejiangUniversityHangzhou310027China CollegeofElectronicInformation HangzhouDianziUniversityHangzhou310018China

Two carboxylation processes were carried out to modify multi-walled carbon nanot ube bundles (m-MWNTs). The results showed that both of the m-MWNTs could be high ly dispersed in water with the concentration up to 25 and 15mg/mL in ethanol wit hout obvious deposition or conglomeration over 6 months. fTIR, Raman, TGA and TE M characterizations of the m- MWNTs showed that hydroxyl and carboxyl groups hav e been attached with MWNTs, and that the nanotube structure was only damaged a l ittle after modification treatments in mixed acids over 24h. Above prepared nano tube suspensions in water were successfully used as a filler of thermoplastic PV A composite to enhance its electrical conductivity. The results showed that the addition of m-MWNTs greatly improved the conductivity and the threshold of mass fraction was about 5wt%. The results also proved that purification process was n ot needed because of high purity of the raw MWNTs prepared in our group.

关键词： carbon nanotube polyvinylalcohol composite conductivity

在线全文

学校读者我要写书评

暂无评论

基于单目RGB图像的三维手部姿态估计方法

浙江大学学报(工学版) 2025年第1期59卷 18-26页

作者：杨冰徐楚阳姚金良向学勤杭州电子科技大学计算机学院浙江杭州310018 杭州电子科技大学浙江省脑机协同智能重点实验室浙江杭州310018 杭州灵伴科技有限公司浙江杭州311121

现有的三维手部姿态估计方法大多基于Transformer技术,未充分利用高分辨率下的局部空间信息,为此提出基于改进fastMETRO的三维手部姿态估计方法.引入可变形注意力机制,使得编码器的设计不再受限于图像特征序列长度;引入交错更新多尺度... 详细信息

现有的三维手部姿态估计方法大多基于Transformer技术,未充分利用高分辨率下的局部空间信息,为此提出基于改进fastMETRO的三维手部姿态估计方法.引入可变形注意力机制,使得编码器的设计不再受限于图像特征序列长度;引入交错更新多尺度特征编码器来融合多尺度特征,强化生成手部姿态;引入图卷积残差模块来挖掘网格顶点间的显式语义联系.为了验证所提方法的有效性,在数据集freiHAND、HO3D V2和HO3D V3上开展训练及评估实验.结果表明,所提方法的回归精度优于现有先进方法,在freiHAND、HO3D V2、HO3D V3上的普鲁克对齐-平均关节点误差分别为5.8、10.0、10.5 mm.

关键词：三维手部姿态估计 Transformer 可变形注意力机制交错更新多尺度特征编码器神经网络

同方期刊数据库

Precise spectroscopy of metastable Li plus using the optical Ramsey technique in support of time dilation tests

在线全文

学校读者我要写书评

暂无评论

PHOTONICS RESEARCH 2025年第1期13卷 201-209页

作者： Zhou, Peng-peng Chen, Shao-long Qin, Cheng-gang Chang, xu-rui Zhou, Zhi-qiang Sun, Wei Huang, Yao Gao, Ke-lin Guan, Hua Chinese Acad Sci Innovat Acad Precis Measurement Sci & Technol State Key Lab Magnet Resonance & Atom & Mol Phys Wuhan 430071 Peoples R China Informat Engn Univ Zhengzhou 450001 Peoples R China Chinese Acad Sci Key Lab Time Reference & Applicat Wuhan 430206 Peoples R China Huazhong Univ Sci & Technol MOE Key Lab Fundamental Phys Quant Measurement Wuhan 430074 Peoples R China Huazhong Univ Sci & Technol Hubei Key Lab Gravitat & Quantum Phys PGMF Wuhan 430074 Peoples R China Huazhong Univ Sci & Technol Sch Phys Wuhan 430074 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Chinese Acad Sci Qinghai Inst Salt Lakes Key Lab Green & High end Utilizat Salt Lake Resour Xining 810008 Peoples R China Wuhan Inst Quantum Technol Wuhan 430206 Peoples R China

Time dilation constitutes a crucial aspect of Lorentz invariance within special relativity and undergoes constant scrutiny through numerous Ives-Stilwell-type experiments employing the Doppler effect. In our study, we employed optical Ramsey spectroscopy on a Li+ ion beam to enhance the precision of measuring the intrinsic transition frequency 23S1 - 23P2 to the level of four parts in 1010 with speed of 0.00035c. Our findings reconciled an existing 2 MHz disparity between collinear and perpendicular laser spectroscopy. furthermore, in conjunction with previous studies on Li+ ion beams traveling at speeds of 0.064c and 0.338c [Nat. Phys. 3, 861 (2007);Phys. Rev. Lett. 113, 120405 (2014)], we updated the Robertson-Mansouri-Sexl parameter alpha to be (-10.0 f 9.9) x 10-8 and (-2.9 f 2.0) x 10-8, respectively. (c) 2024 Chinese Laser Press

关键词： Doppler effect frequency combs Laser beams Nodal aberration theory Optical clocks Optical fields

Gap solitons of spin–orbit-coupled Bose–Einstein condensates in PT periodic potential

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第1期31卷 140-145页

作者： S Wang Y H Liu T f.xu Hebei Key Laboratory of Microstructural Material Physics School of ScienceYanshan UniversityQinhuangdao 066004China School of Science Yanshan UniversityQinhuangdao 066004China

We numerically investigate the gap solitons in Bose–Einstein condensates(BECs)with spin–orbit coupling(SOC)in the parity–time(PT)-symmetric periodic *** find that the depths and periods of the imaginary lattice have an important influence on the shape and stability of these single-peak gap solitons and double-peak gap solitons in the first band *** dynamics of these gap solitons are checked by the split-time-step Crank–Nicolson *** is proved that the depths of the imaginary part of the PT-symmetric periodic potential gradually increase,and the gap solitons become *** the different periods of imaginary part hardly affect the stability of the gap solitons in the corresponding parameter interval.

关键词： gap solitons spin–orbit coupling PT-symmetric periodic potential

同方期刊数据库