首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   199篇
  免费   15篇
儿科学   2篇
妇产科学   6篇
基础医学   19篇
临床医学   20篇
内科学   48篇
皮肤病学   2篇
神经病学   9篇
特种医学   8篇
外科学   13篇
综合类   9篇
预防医学   34篇
药学   35篇
中国医学   7篇
肿瘤学   2篇
  2022年   5篇
  2021年   7篇
  2020年   3篇
  2019年   2篇
  2018年   3篇
  2017年   5篇
  2016年   3篇
  2015年   6篇
  2014年   4篇
  2013年   5篇
  2012年   15篇
  2011年   12篇
  2010年   8篇
  2009年   3篇
  2008年   11篇
  2007年   10篇
  2006年   9篇
  2005年   10篇
  2004年   5篇
  2003年   3篇
  2002年   6篇
  2001年   2篇
  2000年   5篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1994年   2篇
  1993年   1篇
  1991年   2篇
  1990年   3篇
  1989年   7篇
  1988年   4篇
  1987年   7篇
  1986年   5篇
  1985年   6篇
  1984年   1篇
  1983年   5篇
  1982年   1篇
  1981年   2篇
  1979年   2篇
  1978年   3篇
  1977年   2篇
  1976年   2篇
  1975年   4篇
  1974年   1篇
  1973年   3篇
  1972年   2篇
  1971年   1篇
  1969年   1篇
  1967年   1篇
排序方式: 共有214条查询结果,搜索用时 15 毫秒
51.
A 3-year (1997-1999) prospective study was carried out to evaluate the possible role of traditional healers (THs) in the spread of HIV/AIDS in south eastern Nigeria. Their patients' knowledge of HIV infection was also ascertained during the review period. Four contiguous states in south eastern Nigeria with high prevalent rates of HIV infection were chosen for the survey. Sixty-nine patients ofTHs were randomly selected and contacted from the patients' list of five selected THs in each state. Thus, a total of 20 THs and 69 patients formed subjects of the study. The study involved a face-to-face interview of the subjects by trained health personnel in each state using a prepared structured questionnaire. The questionnaire elicited information on their biodata, past/present medical history, social/family history, nature and mode of treatment received or administered, and their knowledge of HIV infection, where applicable. The results showed that there was a serious HIV/AIDS related risk inherent in the practices of Nigerian THs patronized by over 60% of the population. This was suggested by the continuous usage of unsterilized instruments and cross contamination with patients' blood and body fluid in their practices. It was further revealed that, the patients' HIV/AIDS related knowledge was poor (30%). Basic education on HIV/AIDS must be given to all groups in Nigeria including THs, their patients and general public. The World Health Organization and other agencies involved in the fight against HIV infection should focus on the safety of THs' practices as a possible mode of transmission of HIV infection in Africa. Unless this aspect is taken seriously along with other preventive strategies already adopted, the epidemic of the disease condition may continue to spread in Africa.  相似文献   
52.
53.
Platelet adhesion to collagen type IV under flow conditions   总被引:3,自引:2,他引:3  
Collagen type IV is a sheet-forming collagen and a major constituent of the vessel wall. To find out which conditions are important for platelet adhesion to collagen type IV, we performed perfusion studies with anticoagulated blood in parallel plate perfusion chambers. The role of divalent cations was investigated by using plasmas with variable concentrations of Mg2+ and Ca2+ ions. When Mg2+ concentration was decreased from 2.00 mmol/L to 0.25 mmol/L at a fixed Ca2+ concentration of 1.25 mmol/L, platelet coverage on the collagen type IV surface decreased from 22.8% +/- 1.8% (n = 4) to 4.6% +/- 0.6% (n = 4) at a shear rate of 1,600 s-1. Also, platelet aggregate formation on collagen type IV was strongly impaired. A monoclonal antibody against the glycoprotein (Gp) Ib receptor and von Willebrand factor (vWF)- depleted plasma reduced the platelet coverage to collagen type IV to, respectively, 10% and 45% of the control value. Electron microscopy showed that vWF was only present between platelets and between the platelet and the collagen type IV surface, but did not bind elsewhere to collagen type IV. These data indicate that collagen type IV is a reactive collagen for platelets. Differences in physiologic plasma magnesium concentrations may in part explain the differences in platelet reactivity to collagen type IV between individuals, and perhaps contribute to differences in the risk for thrombosis.  相似文献   
54.
Platelet membrane glycoprotein IV (GPIV) is a cell-surface glycoprotein that has been proposed as a receptor for collagen. Recently, it has been shown that platelets with the Naka-negative phenotype lack GPIV on their surface, whereas donors with this phenotype are healthy and do not suffer from hematologic disorders. In this study, we compared Naka- negative platelets with normal platelets in adhesion to collagen types I, III, IV, and V and the extracellular matrix of endothelial cells (ECM) under static and flow conditions. No differences in platelet adhesion and subsequent aggregate formation on the collagens types I, III, and IV were observed under static and flow conditions. Adhesion of both homozygous and heterozygous Naka-negative platelets to collagen type V was strongly reduced under static conditions. Collagen type V was not adhesive under flow conditions. No difference in platelet adhesion to ECM was observed, which suggests that GPIV is not important in adhesion to subendothelium, for which ECM may serve as a model. These results indicate that GPIV is not a functional receptor for collagen under flow conditions.  相似文献   
55.
56.
Although ICEP is an exceptionally rare disease, it is potentially overlooked and misdiagnosed. This case highlights the importance of peripheral eosinophilia in raising suspicion for ICEP. Without treatment, majority of patients fail to improve.  相似文献   
57.
This study examined the socio-demographic and selected behavioral characteristics associated with self-perceived and epidemiologic notions of risk for acquiring STIs/HIV infection using data from a cross-sectional survey involving 346 consenting female military personnel from two cantonments in Southwestern Nigeria. Findings revealed significant discordance in participants’ risk status based on the two assessment methods, with Kappa coefficients ranging from ?0.021 to 0.115. Using epidemiologic assessment as the “gold standard”, 45.4% of the study population were able to accurately assess their risk levels through self-perception with significant (P < 0.01) socio-demographic variations. Multivariate logistic regression analyses indicate that STIs/HIV risk models using both self-perceived and epidemiologic notions of risk were significantly determined by different set of covariates. It is recommended that STIs/HIV prevention intervention should integrate the identified covariates and be targeted at changing individual risk behaviors and perceptions, as well as the social contexts in which risky behaviors occur in the military population.  相似文献   
58.
Genetic linkage studies worldwide have proposed various chromosomal localizations for prostate cancer susceptibility genes. A recent study found evidence for linkage to chromosome 1q42.2-43. The aim of our study was to attempt to confirm these findings by performing linkage analysis in 131 families with multiple prostate cancer cases selected from the ACTANE (Anglo, Canada, Texas, Australia, Norway, EU Biomed) Consortium. Parametric and non-parametric linkage (NPL) analyses were performed. Two-point LOD scores failed to show evidence of linkage at any marker (maximum two-point LOD score = 0. 40 at recombination fraction theta = 0.2 with marker D1S2850). Using a multipoint heterogeneity analysis, the estimated proportion of families linked to this putative locus (alpha) was 0% (95% CI = 0. 00-0.33). Non-parametric linkage analysis also found no evidence of linkage (maximum NPL score = -0.12, P = 0.55). This analysis of 131 ACTANE families does not support the presence of a locus for a prostate cancer susceptibility gene at 1q42.2-43. Although we cannot rule out the existence of such a locus, analysis indicates that less than 16% of families could be linked to this region. These findings may be a reflection of the locus heterogeneity involved in this disease indicating that there are still other major susceptibility loci to be identified.  相似文献   
59.
BACKGROUND: Previous research has highlighted the advantages of individual patient data (IPD) meta-analyses. However, they are resource intensive and take considerable time to complete. The aim of this study was to determine whether the extra investment is justified by greater accuracy or usefulness by means of a case study in surgery. METHODS: An updated review using IPD, where possible, was compared with an earlier version based on aggregate published data to determine whether there were statistically significant changes in estimates of effectiveness for hernia recurrence and persisting pain. Differences related to the type of laparoscopic repair, the type of open repair and methodological quality were also explored. RESULTS: The results for hernia recurrence changed little. However, the IPD update led to divergent conclusions for persisting pain. The published data implied a statistically significant benefit in favour of open repair, whereas the IPD result implied a statistically significant benefit in favour of laparoscopic repair (P < 0.001). Methodological quality did not account for this difference. CONCLUSION: Updating of systematic reviews using IPD can be conducted successfully in surgery. This example led to little change in estimates of effectiveness for hernia recurrence but yielded qualitatively different estimates for persisting pain, an outcome rarely included in the published reports.  相似文献   
60.
OBJECTIVES: To assess the relative cost-effectiveness of laparoscopic methods of inguinal hernia repair compared with open flat mesh and open non-mesh repair. METHODS: Data on the effectiveness of these alternatives came from three systematic reviews comparing: (i) laparoscopic methods with open flat mesh or non-mesh methods; (ii) open flat mesh with open non-mesh repair; and (iii) methods that used synthetic mesh to repair the hernia defect with those that did not. Data on costs were obtained from the authors of economic evaluations previously conducted alongside trials included in the reviews. A Markov model was used to model cost-effectiveness for a five-year period after the initial operation. The outcomes of the model were presented using a balance sheet approach and as cost per hernia recurrence avoided and cost per extra day at usual activities. RESULTS: Open flat mesh was the most cost-effective method of preventing recurrences. Laparoscopic repair provided a shorter period of convalescence and less long-term pain compared with open flat mesh but was more costly. The mean incremental cost per additional day back at usual activities compared with open flat mesh was Euro 38 and Euro 80 for totally extraperitoneal and transabdominal preperitoneal repair, respectively. CONCLUSIONS: Laparoscopic repair is not cost-effective compared with open flat mesh repair in terms of cost per recurrence avoided. Decisions about the use of laparoscopic repair depend on whether the benefits (reduced pain and earlier return to usual activities) outweigh the extra costs and intraoperative risks. On the evidence presented here, these extra costs are unlikely to be offset by the short-term benefits of laparoscopic repair.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号