检索结果-南通市图书馆

A STUDY ON TRANSIENT FLUID FLOW OF HORIZONTAL WELLS IN DUAL-PERMEABILITY MEDIA

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2010年第1期22卷 44-50页

作者： WANG xiao-dong ZHOU ying-fang LUO Wan-jing School of Energy Resources China University of Geosciences Beijing 100083 China

To adopt horizontal wells in dual media reservoirs, a good understanding of the related fluid flows is necessary. Most of the recent studies focus on dual porosity media instead of dual permeability media. In this article, through both integral transformation and sink-source superposition, a new Laplace-domain solution is obtained for the slightly-compressible fluid flow in the 3-D dual-permeability media in which the horizontal well is operating in a constant rate of production. Major asymptotic characteristics of diagnosis curves of dimensionless downhole pressure are analyzed by the limited analysis. Effects of parameters of dual-permeability media including mobility ratio k, storativity ratio ω and inter-porosity flow parameter k on the downhote pressure are studied by using the Laplace numerical inversion. The new solution obtained in this article includes and improves the previous results and then can be used as a basis for either pressure transient analysis or formation behavior evaluation for the typical reservoir with horizontal wells.

关键词： horizontal well dual-permeability media fluid flow in 3-D porous media transient pressure analysis Laplacetransformation

System utility based resource allocation for multi-cell OFDM system

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2010年第2期17卷 14-18,45页

作者： HAO Zhi-jie XU xiao-dong ZHAO ying-hong TAO xiao-feng LI Lin-jun ZHANG Zhong-qi Wireless Technology Innovation Institute Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Utility based resource allocation strategy in multi-cell orthogonal frequency-division multiplexing （OFDM） system plays a critical role in next generation mobile communication systems. Based on the analysis of risk aversion utility functions, this article proposed the system utility based utility, which is named the customer satisfaction （CS） utility. Compared with the proportional fairness （PF） utility, the CS utility reflects the user demands better, and enables the system to adjust its resource allocation according to both the traffic requirements and the resource situation.

关键词： OFDM resource allocation utility multi-cell

Response of Soil Phosphorus Required for Maximum Growth of Asparagus officinalis L. to Inoculation of Arbuscular Mycorrhizal Fungi

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2014年第6期24卷 776-782页

作者： XU Ping LIANG Lin-Zhou dong xiao-ying XU Jing JIANG Pei-Kun SHEN Ren-Fang State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of Sciences University of Chinese Academy of Sciences Zhejiang Provincial Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration Zhejiang A & F University

Fertilizer application efficiently increases crop yield, but may result in phosphorus(P) accumulation in soil, which increases the risk of aquatic eutrophication. Arbuscular mycorrhizal fungi(AMF) inoculation is a potential method to enhance P uptake by plant and to reduce fertilizer input requirements. However, there has been limited research on how much P application could be reduced by AMF inoculation. In this study, a pot experiment growing asparagus(Asparagus officinalis L.) was designed to investigate the effects of AMF inoculation and six levels of soil Olsen-P(10.4, 17.1, 30.9, 40.0, 62.1, and 95.5 mg kg-1for P0, P1, P2, P3, P4 and P5treatments, respectively) on root colonization, soil spore density, and the growth and P uptake of asparagus. The highest root colonization and soil spore density were both obtained in the P1treatment(76% and 26.3 spores g-1soil, respectively). Mycorrhizal dependency significantly(P < 0.05) decreased with increasing soil Olsen-P. A significant correlation(P < 0.01) was observed between mycorrhizal P uptake and root colonization, indicating that AMF contributed to increased P uptake and subsequent plant *** quadratic equations of shoot dry weight and soil Olsen-P showed that AMF decreased the P concentration of soil required for maximum plant growth by 14.5% from 67.9 to 59.3 mg Olsen-P kg-1. Our results suggested that AMF improved P efficiency via increased P uptake and optimal growth by adding AMF to the suitable P fertilization.

关键词： asparagus mycorrhizal dependence phosphorus-utilization efficiency root colonization spore density

Recent progress of pediatric cardiac surgery in China

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2006年第23期119卷 2005-2012页

作者： WU Kai-hong LU xiao-dong LIU ying-long Pediatric Cardiac Center Department of Surgery CardiovascularInstitute and Fuwai Hospital Chinese Academy of MedicalSciences and Peking Union Medical College Beijing 100037China

Pediatric cardiac surgery in China has madegreat progress since the first successful open heart operation for correction of ventricular septal defect （VSD） with an artificial heart-lung machine in 1958.1 In recent years, the state has paid much attention to both the basic research and the primary, secondary and tertiary prevention of congenital heart disease. The surgical treatment for congenital heart diseases in infancy was listed as one of the Family Planning Technology Specific Projects among the Key Tasks in the Tenth Five-Year Plan. Due to economic and social conditions in China primary or secondary prevention and treatment of congenital heart disease are still in the early phase of development. Therefore, tertiary prevention -- surgical treatment--is still of crucial importance. Here we review the current status of pediatric cardiac surgery in China and highlight the latest advances in this exciting field.

关键词： cardiac surgery cardiopulmonary bypass congenital heart defect pediatrics

Incidence of congenital heart disease in Beijing, China

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2009年第10期122卷 1128-1132页

作者： YANG Xue-yong LI xiao-feng LV xiao-dong LIU ying-long Pediatric Cardiac Center Department of Surgery Cardiovascular Institute and Fu Wai Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100037 China

Background The incidence of congenital heart disease has been studied in developed countries for many years, but rarely in the mainland of China. Fetal echocardiographic screening for congenital heart disease was first performed in Beijing in the early 2000s, but the impact was not clear. The current study was undertaken to determine the incidence of congenital heart disease in Beijing, China and to estimate the impact of fetal echocardiography on the incidence of liveborn congenital heart disease.Methods The study involved all infants with congenital heart disease among the 84 062 total births in Beijing during the period of January 1 and December 31, 2007. An echocardiographic examination was performed on every baby suspected to have congenital heart disease, prenatally or/and postnatally.Results A total of 686 infants were shown to have congenital heart disease among 84 062 total births. The overall incidence was 8.2/1000 total births. Mothers of 128 of 151 babies diagnosed prenatally were chosen to terminate the pregnancy. Two of the 151 infants died in utero. A specific lesion was identified for each infant and the frequencies of lesions were determined for each class of infants （total births, stillbirths and live births）. The incidence of congenital heart disease in stillbirths and live births was 168.8/1000 and 6.7/1000, respectively. The difference between the incidence of total birth and the incidence of live birth was statistically significant （P 〈0.001）. Conclusions The incidence of liveborn congenital heart disease in Beijing is within the range reported in developed countries. Fetal echocardiography reduce significantly the incidence of liveborn congenital heart disease.

关键词： incidence congenital heart disease prenatal diagnosis fetal echocardiography pregnancy termination

Fasudil inhibits platelet-derived growth factor-induced human pulmonary artery smooth muscle cell proliferation by up-regulation of p27^kipl via the ERK signal pathway

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 Medical Journal 2011年第19期124卷 3098-3104页

作者： LIU Ai-jun LING Feng WANG dong WANG Qiang LU xiao-dong LIU ying-long Department of Pediatric Cardiac Surgery Center Fuwai Hospital Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100037 China

Background RhoA/ Rho kinase （ROCK） pathway is involved in pulmonary arterial hypertension （PAH） and pulmonary artery smooth muscle cell （PASMC） proliferation. Inhibition of ROCK has been proposed as a treatment for PAH. But the mechanism of RhoA/ROCK pathway and its downstream signaling in proliferation of human PASMCs is unclear. We investigated the effect of fasudil, a selective ROCK inhibitor, on platelet-derived growth factor （PDGF） induced human PASMC proliferation, and the possible association between RhoA/ROCK and extracellular signal-regulated kinase （ERK）,*** Human PASMCs were cultured with the stimulation of 10 ng/ml PDGF, and different concentrations of fasudil were added before the addition of mitogen. Cell viability and cell cycle were determined with MTT and flow cytometry respectively. ROCK activity, ERK activity and protein expression of proliferating cell nuclear angigen （PCNA） and p27Kip1 were measured by *** By MTT assay, PDGF significantly increased the OD value that represented human PASMC proliferation, and pretreatment with fasudil significantly reversed this effect in a dose-dependent manner. After PDGF stimulation, the percentage of cells in S phase increased dramatically from 15.6% to 24.3%, while the percentage in G0/G1 phase was reduced from 80.6% to 59%. And pretreatment with fasudil reversed the cell cycle effect of PDGF significantly in a dose-dependent manner. PDGF markedly induced ROCK activity and ERK activity with a peak at 15 minutes, which were significantly inhibited by fasudil. In addition, fasudil significantly inhibited PDGF-induced PCNA expression and fasudil also upregulated p27Kip1 expression in human PASMCs, which decreased after PDGF *** RhoA/ROCK is vital for PDFG-induced human PASMC proliferation, and fasudil effectively inhibited PDGF-induced human PASMC proliferation by up-regulation of p27Kip1, which may be associated with inhibition of ERK activity.

关键词： human pulmonary smooth muscle cell proliferation Rho-kinase fasudil extracellular signal-regulated kinase p27^kip1

Chem oprevention of 2-amino-1-methyl-6-phenyli-midazo[4,5-b]pyridine-induced carcinogen-DNA adducts by Chinese cabbage in rats

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 1999年第2期5卷 50-54页

作者： TAN Wen 1, LIN dong Xin 1, xiao ying 2,FF Kadlubar 3 and CHEN Jun Shi 4

AIM The food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces colon and mammary gland tumors in rats and has been implicated in the etiology of human colorectal cancer. This study was conducted to examine the potentially preventive effect of Chinese cabbage (Brassica chinensis), a brassica vegetable most commonly consumed in China, against this carcinogen-induced DNA adduct formation in rats and its possible *** Sprague-Dawley rats were maintained for 10 days on basal diet or diet containing 20% (w/ w) freeze-dried cabbage powder prior to administration of a single dose of PhIP (10 mg/ kg) by oral gavage. Rats were sacrificed at 20 h after PhIP treatment and PhIP-DNA adducts in the colon, heart, lung and liver were analyzed using 32P-postlabeling technique. Levels of hepatic cytochrome P450 (CYP) 1A1 and 1A2, as indicated by 7-ethoxyresorufin O-deethylase and 7-methlxyresorufin O-demethylase activity, and cytosolic glutathione S-transferases (GSTs) towards 1-chloro-2, 4-dinitrobenzene (CDNB) in the liver, lung and colon were *** Rats pre-treated with Chinese cabbage and given a single dose of PhIP had reduced levels of PhIP-DNA adducts in the colon, heart, lung and liver, with inhibition rates of 82.3%, 60.6%, 48.4% and 48.9%, respectively (P＜0.01). The enzyme assays revealed that Chinese cabbage induced both CYP1A1 and 1A2 activity, but the induction was preferential for CYP1A1 over 1A2 (81% vs 51%). GST activity towards CDNB in the liver and lung, but not colon, was also significantly increased by cabbage *** The results indicate that Chinese cabbage has a preventive effect on PhIP-initiated carcinogenesis in rats and the mechanism is likely to involve the induction of detoxification enzymes.

关键词： heterocyclic amine DNA adduct Brassica vegetable colonic neoplasms cytochrome P450

Protective effect of chrysoeriol against doxorubicin-induced cardiotoxicity in vitro

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 Medical Journal 2009年第21期122卷 2652-2656页

作者： LIU Zhe SONG xiao-dong XIN ying WANG xiao-jian YU Hui BAI Yong-yi LIU Jun-hao HANG Chan-na HUI Ru-tai Sino-German Laboratory for Molecular Medicine Key Laboratory for Clinical Cardiovascular Genetics of Ministry of Education Cardiovascular Institute & Fu Wai Hospital Chinese Academy of Medical Sciences Peking Union Medical College Beijing 100037 China

Background The use of doxorubicin （DOX） is limited by its dose-dependent cardiotoxicity. Reactive oxygen species （ROSs） play an important role in the pathological process of DOX-induced cardiotoxicity. The aim of this study was to evaluate the protective effect of chrysoeriol, a flavone compound, against DOX-induced apoptosis and death in H9c2 cells and to find out its preliminary mechanism. Methods We used 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl-2H-tetrazolium bromide （MTT） assay, Hoechst33258 staining and measurement of lactate dehydrogenase （LDH） release to evaluate the protective effect of chrysoeriol against DOX-induced apoptosis and death in H9c2 cells. To find out the mechanism of this protective effect, we observed the immunofluorescence of intracellular ROS and measured the activities of malondialdehyde （MDA）, superoxide dismutase （SOD） and glutathione peroxidase （GPx）. Furthermore, we evaluated the effect of chrysoeriol on the antitumor activity of DOX in HeLa cells with MTT assay. Results The results of MTT assay, Hoechst 33258 staining and measurement of LDH release showed that chrysoeriol significantly reduced doxorubicin-induced apoptosis and cell death. Chrysoeriol at a dose of 20 μg/ml notably reduced intracellular ROS, decreased the concentration of MDA in the supernatant of DOX-treated H9c2 cells and increased SOD and GPx activities to their normal levels. Further study showed that the addition of chrysoeriol did not affect the antitumor activity of DOX. Conclusion Chrysoeriol could potentially serve as a novel cardioprotective agent against DOX-induced cardiotoxicity without affecting the antitumor activity of DOX.

关键词： chrysoeriol doxorubicin cardiotoxicity reactive oxygen species

在线全文

学校读者我要写书评

暂无评论

基于高层支持与信息化咨询的知识转移研究

商业研究 2011年第9期 13-18页

作者：巩见刚董小英北京大学光华管理学院北京100871

知识转移是企业信息系统实施的重要一环,本文在已有研究的基础上从领导角度出发,以华为IPD项目为案例,探讨了高层领导支持与知识转移之间的关系,认为高层认知以及高层对信息化工作的支持直接影响知识转移环境的塑造,进而促进知识转移的... 详细信息

知识转移是企业信息系统实施的重要一环,本文在已有研究的基础上从领导角度出发,以华为IPD项目为案例,探讨了高层领导支持与知识转移之间的关系,认为高层认知以及高层对信息化工作的支持直接影响知识转移环境的塑造,进而促进知识转移的成功。

关键词：高层支持知识转移信息系统