检索结果-南通市图书馆

Development of tourism resources and environment conservation in China: with special reference to Taishan Mountain

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 1991年第3期3卷 99-104页

作者： Liu JihanDepartment of Geography,peking university,Beijing 100871,China

By analyzing the cases in Taishan Mountain, Shandong Province and other tourist sites in China, this paper pointed out the problems in tourism management, such as resources damage, environment pollution, which are the result of tourism development, and are obstacles to the development. The paper also gave suggestion and practical ways to preserve tourism resources and environment.

关键词： tourism resources environment conservation Taishan Mountain tourism development.

CONVERGENCE OF CHORIN-MARSDEN FOR MULA FOR THENAVIER-STOKES EQUATIONS ON CONVEX DOMAINS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1999年第1期17卷 73-88页

作者： Lung-an Ying(Research institute for Mathematical Sciences, Kyoto university, Japan Department of Mathematics, peking university, Beijing 100871, China) 北京大学数学系北京

We prove the convergence of the Chorin-Marsden product formula for solving the initial-boundary value problems of the Navier-Stokes equations on convex domains. As a particular case we consider the case of the half pl... 详细信息

关键词： Navier Stokes equation vortex method fractional step method convergence

Insulin improves cardiomyocyte contractile function through enhancement of SERCA2. activity in simulated ischemia/reperfusion

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2006年第7期27卷 919-926页

作者： Jie YU~2.Hai-feng ZHANG~2.Feng WU~2.Qiu-xia LI~2.Heng MA~2.Wen-yi GUO~3 Hai-chang WANG~3 Feng GAO~(2.3,4,5)2.Department of Physiology3 Department of Cardiology,Xijing Hospital,Fourth Military Medical university,Xi'an 710032.China 4 Institute of Molecular Medicine,peking university,Beijing 100871,China DepartmentofPhysiology XijingHospitalFourthMilitaryMedicalUniversityXi'an710032China DepartmentofCardiology XijingHospitalFourthMilitaryMedicalUniversityXi'an710032China InstituteofMolecularMedicine Peking

Aim:Insulin exerts anti-apoptotic effects in both cardiomyocytes and coronaryendothelial cells following ischemia/reperfusion（I/R）via the Akt-endothelial ni-tric oxide synthase survival signal *** important insulin signalingmight further contribute to the improvement of cardiac function after *** this study,we tested the hypothesis that sarcoplasmic reticulum calcium-AT-Pase（SERCA2.）is involved in the insulin-induced improvement of cardiac con-tractile function following I/***:Ventricular myocytes were enzymaticallyisolated from adult SD *** I/R was induced by perfusing cells withchemical anoxic solution for 15 min followed by reperfusion with Tyrode's solu-tion with or without insulin for 30 *** shortening and intracellularcalcium transients were assessed and underlying mechanisms were ***:Reperfusion with insulin(10-7mol/L)significantly improved the recoveryof contractile function（n=15-2. myocytes from 6-8 hearts,P2.)fluorescenceratio,shortened time to peak Ca2.and time to 50% diastolic Ca2.,compared withthose in cells reperfused with vehicle（P2. activity were both increased in insulin-treated I/R cardiomyocytes,which were markedly inhibited by pretreatment of cells with a specific Akt ***,inhibition of Akt activity abolished insulin-induced positive contrac-tile and calcium transients responses in I/R ***:Thesedata demonstrated for the first time that insulin improves the recovery of contrac-tile function in simulated I/R cardiomyocytes in an Akt-dependent and SERCA2.-mediated fashion.

关键词： insulin ischemia/reperfusion cardiomyocyte contraction calcium transients SERCA2. Akt

X-ray flares of γ-ray bursts: Quakes of solid quark stars?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2009年第2期52卷 315-320页

作者： XU RenXin1 & LIANG EnWei2.1 School of Physics and State Key Laboratory of Nuclear Physics and Technology, peking university, Beijing 100871, China 2.Department of Physics, Guangxi university, Nanning 530004, China School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University Beijing China Department of Physics Guangxi University Nanning China

A star-quake model is proposed to understand X-ray flares of both long and short γ-ray bursts (GRBs) in a solid quark star regime. Two kinds of central engines for GRBs are available if pulsar-like stars are actually (solid) quark stars, i.e., the SNE-type GRBs and the SGR-type GRBs. It is found that a quark star could be solidified about 103 to 106 s later after its birth if the critical temperature of phase transi- tion is a few Metga-electron-volts, and then a new source of free energy (i.e., elastic and gravitational ones, rather than rotational or magnetic energy) could be possible to power GRB X-ray flares.

关键词： γ-rays bursts: X-rays neutron stars elementary particles

Adeno-associated virus-mediated bone morphogenetic protein-7 gene transfer induces C2.12.cell differentiation into osteoblast lineage cells

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2005年第8期26卷 963-968页

作者： Min YANG~2. Qing-jun MA~(2.4), Geng-ting DANG~2. Kang-tao MA~3, Ping CHEN~3, Chun-yan ZHOU~(3,4) ~2.epartment of Orthopedics, peking university Third Hospital, Beijing 100083, China ~3Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, peking university Health Science Center, Beijing 100083, China DepartmentofOrthopedics PekingUniversityThirdHospitalBeijing100083China

Aim: To investigate the effects of bone morphogenetic protein-7 (BMP7)-expressing recombinant adeno-associated virus (AAV) vector on the differentiation of C2.12.cells. Methods: AAV-BMP7 was packaged by infecting the stable cell clone BHK-2. (integrated with recombinant AAV vector plasmid pSNAV-BMP7) with recombinant herpes simplex virus type 1, which expresses AAV-2.Rep and Cap and possesses AAV packaging functions. Following infection with AAV-BMP7 at multiplicities of infection of lx 10～5 vector genomes per cell and subse-quent culture, C2.12.cells were assessed qualitatively for BMP7 production, alka-line phosphatase activity, osteocalcin production and Cbfal and MyoD expression. Results: C2.12.cells transduced with AAV-BMP7 could produce BMP7 protein until d 2.. Alkaline phosphatase in the cultured C2.12.cell lysate was elevated. Secreted osteocalcin in the culture medium was detectable at d 12.and Cbfal mRNA expression level was upregulated, coinciding with downregulation of MyoD in a temporal manner. Conclusion: The present in vitro study demonstrated that AAV-BMP7 could infect and efficiently convert C2.12.cells from myoblasts into osteoblast lineage cells.

关键词： C2.12 adeno-associated virus bone morphogenetic protein-7 gene therapy

L~∞ CONVERGENCE OF QUASI-CONFORMING FINITE ELEMENTS FOR THE BIHARMONIC EQUATION

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1995年第2期13卷 108-122页

作者： Wang Ming (Department of Mathematics, peking university, Beijing, China) 北京大学数学系北京

In this paper we consider the L∞ convergence for quasi-conforming finite ele-ments solving the boundary value probzlems of the biharmonic equation and give the nearly optimal order L∞ estimates.

关键词：双调和方程拟共形有限元 L↑∞收敛性 L↑∞估计

p38 MAPK mediates cardiovascular and behavioral responses induced by central IL-1β and footshock in conscious rats

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第3期25卷 12-16页

作者： Rui-mao ZHENG,Chang-jiang ZOU,Shi-gong ZHU2.Department of Physiology and Pathophysiology,Health Science Center,peking university,Beijing 100083,China Department of Physiology and Pathophysiology Health Science Center Peking University 北京 100083

AIM: To investigate the roles of p38 mitogen-activated protein kinase (p38 MAPK) in the cardiovascular and behavioral responses induced by intracerebral ventricular injection (icv) of interleukin-1β (IL-1β) or footshock. METHODS: We examined the effects of p38 MAPK on mean artery blood pressure (mABP), heart rate (HR), and motor activity (MA) during central administration of IL-1β, or footshock after icv SB2.3580 (a specific inhibitor of the p38 MAPK) with Cardiovascular and Behavior Telemetry System in conscious SD rats. RESULTS: (1) IL-1β (icv) or footshock remarkably rise the mABP, and the maximal changes are (7.8±1.8) and (12.3±3.5) mmHg, respectively, which was abrogated by the pretreatment with p38 inhibitor SB2.3580 intracerebroventricularly. (2. Compared with icv saline group, the motor activity was significantly decreased in SB2.3580 group with maximal changes (-7.6±1.1) counts/min after footshock. CONCLUSION: p38 MAPK plays an important role in the pres- sor response induced by central administration of IL-1β or footshock and change of motor activity after footshock in conscious rats.

关键词： mitogen-activated protein kinase p38 interleukin-1 blood pressure motor activity

Rat CC chemokine receptor 4 is the functional homologue of human CC chemokine receptor 4 and can interact with human CCL17 and CCL2.

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 Science Bulletin 2010年第14期55卷 1388-1395页

作者： TIAN LinJie1,2. QI Hui1,2. XIE Yuan1,2. ZHANG YingMei1,2. ZHANG WenJuan1,2. SUN XiangYu1,2. WANG Ying1,2.& MA DaLong1,2.1 Laboratory of Medical Immunology, School of Basic Medical Science, peking university Health Science Center, Beijing 100191, China 2.Human Disease Genomics Center, peking university, Beijing 100191, China Laboratory of Medical Immunology School of Basic Medical Science Peking University Health Science Center Beijing China Human Disease Genomics Center Peking University Beijing China

Human CCL17/TARC (hCCL17) and CCL2./MDC (hCCL2.) interact with their receptor CCR4, playing pivotal roles in various Th2.cell-dominant diseases. Rat Ccl17, Ccl2. and Ccr4 share 63.4%, 65.2. and 87.5% homology at the amino acid level, respectively, compared with their human homologues. Rat Ccl2. has been demonstrated to interact with rat Ccr4. However, it is not known whether rat Ccl17 is a functional ligand for rat Ccr4 and whether rat Ccr4 can interact with hCCL17 and hCCL2.. In this study, we cloned rat Ccl17 and Ccr4 cDNA from rat thymus and expressed the recombinant rat Ccl17. The binding assay indicated rat Ccl17 could saturably bind rat Ccr4, and this binding could be competitively inhibited by unlabeled rat Cc17, hCCL17 or hCCL2.. Both rat and human CCL17 or CCL2. could induce the chemotactic migration and calcium mobilization in rat Ccr4-transfected cells. They could also desensitize each other’s effect on chemotaxis and calcium mobilization. Furthermore, both rat Ccl17 and hCCL17 could induce significant receptor internalization in rat Ccr4-EGFP transfected cells. These results demonstrated the conserved CCL17/CCR4 interaction in rats and the further cross-species interaction of rat Ccr4 with hCCL17 and hCCL2.. Likewise, they provided the molecular basis for the investigation of physiological and pharmacological roles of CCR4, its ligands, and their antagonists in rat disease models.

关键词：趋化因子受体同源性大鼠人类基因转染细胞绿色荧光蛋白相互作用疾病模型

Biotic communities of the marine ecosystem in Meizhou Bay

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 1996年第1期8卷 48-56页

作者： Ren Jiuchang Cai Xiaoming (Center of Environmental Sciences,peking university, Beijing 100871,China)Chen Bin(College of Life Sciences, peking university, Beijing 100871, China )Li Peng(College of Chemistry and Molecular Engineering, peking university, Bei Ctr of Envmtl Sci Peking Univ Beijing China China

The current situation of biotic communities in Meizhou Bay is presented in this *** species composition,seasonal variation,and distribution of phytoplankton,zooplankton, red tide organisms,fishes,and benthos in Meizhou Bay were investigated,and the content of chlorophyll a and primary production and their seasonal variation were also *** water quality of Meizhou Bay was monitored by measuring the density of Escherichia coli. Results reveal that there is a great variety of species in Meizhou Bay and the water in Meizhou Bay is *** the individual numbers of various organisms are very low, especially those of ***,there are more than 40 species of red tide organisms and there exist opportunities of red tides between May and *** these demand cautious be taken in the future development of this area although it has great environment capacity.

关键词： biotic community marine ecosystem Meizhou Bay.