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   397篇
  免费   23篇
  国内免费   8篇
儿科学   34篇
妇产科学   3篇
基础医学   39篇
口腔科学   13篇
临床医学   34篇
内科学   115篇
皮肤病学   9篇
神经病学   12篇
特种医学   65篇
外科学   20篇
综合类   9篇
预防医学   12篇
眼科学   17篇
药学   24篇
肿瘤学   22篇
  2022年   2篇
  2021年   5篇
  2020年   3篇
  2019年   8篇
  2018年   7篇
  2017年   7篇
  2016年   2篇
  2015年   9篇
  2014年   8篇
  2013年   14篇
  2012年   11篇
  2011年   15篇
  2010年   17篇
  2009年   17篇
  2008年   12篇
  2007年   12篇
  2006年   11篇
  2005年   14篇
  2004年   6篇
  2003年   17篇
  2002年   9篇
  2001年   10篇
  2000年   2篇
  1999年   5篇
  1998年   21篇
  1997年   18篇
  1996年   20篇
  1995年   15篇
  1994年   9篇
  1993年   6篇
  1990年   3篇
  1989年   7篇
  1988年   11篇
  1987年   6篇
  1986年   6篇
  1985年   6篇
  1984年   4篇
  1982年   4篇
  1981年   11篇
  1980年   6篇
  1979年   11篇
  1978年   5篇
  1977年   10篇
  1976年   8篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1948年   2篇
  1925年   1篇
  1924年   1篇
排序方式: 共有428条查询结果,搜索用时 9 毫秒
1.
Complications from improperly placed biliary stents are not uncommon. Free loose wires from the ends of an uncovered stent can irritate and damage adjacent mucosal surfaces. Effective management can be achieved via percutaneous placement of a second stent to alter the orientation of the original stent.  相似文献   
2.
3.
The efficiency of antigen (Ag) processing by dendritic cells (DCs) is vital for the strength of the ensuing T‐cell responses. Previously, we and others have shown that in comparison to protein vaccines, vaccination with synthetic long peptides (SLPs) has shown more promising (pre‐)clinical results. Here, we studied the unknown mechanisms underlying the observed vaccine efficacy of SLPs. We report an in vitro processing analysis of SLPs for MHC class I and class II presentation by murine DCs and human monocyte‐derived DCs. Compared to protein, SLPs were rapidly and much more efficiently processed by DCs, resulting in an increased presentation to CD4+ and CD8+ T cells. The mechanism of access to MHC class I loading appeared to differ between the two forms of Ag. Whereas whole soluble protein Ag ended up largely in endolysosomes, SLPs were detected very rapidly outside the endolysosomes after internalization by DCs, followed by proteasome‐ and transporter associated with Ag processing‐dependent MHC class I presentation. Compared to the slower processing route taken by whole protein Ags, our results indicate that the efficient internalization of SLPs, accomplished by DCs but not by B or T cells and characterized by a different and faster intracellular routing, leads to enhanced CD8+ T‐cell activation.  相似文献   
4.
5.
6.

Background  

Childhood obesity is a substantial public health problem. The extent to which health state preferences (utilities) are related to a child's weight status has not been reported. The aims of this study were (1) to use a generic health state classification system to measure health related quality of life and calculate health utilities in a convenience sample of children and adolescents and (2) to determine the extent to which these measures are associated with weight status and body mass index (BMI).  相似文献   
7.

Objectives

To analyze the concept of “case series” in the medical literature compared with case reports.

Methods

A PubMed search for articles published during 2009 which had “case series” in their title was performed. A total number of 621 articles were retrieved. 586 papers were included in the analysis and 35 were excluded (18 were commentary letters, 5 were not in English, and twelve could not be retrieved by our Library). The number of patients and category of these articles were analyzed.

Results

The median (range) of the number of cases of articles having “case series” in their title was 7 (1–6432) cases. 186/ 586 articles had less than 5 cases (31.7%, 95% CI (28.3–35.1%)). The median (range) of the number of cases of articles having “case report” as their publication type was 4 (1–178) cases. Out of the 219 articles categorized as case reports 114 (52.1%, 95% CI (45.6–58.6%)) had less than five cases.

Conclusions

The concept of “case series” is not well defined in the literature and does not reflect a specific research design. We suggest that a case series should have more than four patients while four paitents or less should be reported individually as case reports.  相似文献   
8.

Background

Critically-ill trauma patients have a high mortality.

Objective

To study the factors affecting the mortality of ICU trauma patients treated at Al-Ain Hospital, United Arab Emirates (UAE).

Methods

All trauma patients who were admitted to the ICU were prospectively collected over three years (2003–2006). Univariate and multivariate analysis were used to compare patients who died and who did not. Gender, age, nationality, mechanism of injury, systolic blood pressure and GCS on arrival, the need for ventilation, presence of head or chest injuries, AIS for the chest and head injuries and the ISS were studied.

Results

There were 202 patients (181 males). The most common mechanism of injury was road traffic collisions (72.3 %). The overall mortality was 13.9%. A direct logistic regression model has shown that factors that affected mortality were decreased GCS (p < 0.0001), mechanism of injury (p = 0.004) with burns having the highest mortality, increased age (p = 0.004), and increased ISS (p = 0.02). The best GCS that predicted mortality was 5.5 while the best ISS that predicted mortality was 13.5.

Conclusion

Road traffic collision is the most common cause of serious trauma in UAE followed by falls. Decreased GCS was the most significant factor that predicted mortality in the ICU trauma patients.  相似文献   
9.
Genital asymmetry in men   总被引:1,自引:0,他引:1  
This study examined genital asymmetry in a large sample of men. The probands were 6544 non-delinquent men who were interviewed by the Kinsey Institute for Research in Sex, Gender and Reproduction from 1938 to 1963. The measures were four indicators of penile and scrotal asymmetry, along with self-reported handedness, from Kinsey's interview protocol. Most men reported some degree of lateral asymmetry in their flaccid penis and in their testicles; less asymmetry was reported for their erect penis. The asymmetry typically occurred in the left direction, and this pattern occurred in both right- and nonright- handers. However, this 'leftward' pattern was significantly less pronounced in nonright-handers. The results are discussed in relation to previous findings of genital asymmetry in men, the possible relationship of genital asymmetry to functional cerebral asymmetry, and recent data suggesting genital asymmetry may predict patterns of cognitive performance and genital/sexual organ cancers.   相似文献   
10.
Koller  CA; LoBuglio  AF 《Blood》1981,58(2):293-299
Human monocytes respond to opsonized microorganisms with a "metabolic burst" composed of an increase in oxygen consumption, an increase in hexose monophosphate shunt (HMPS) activity, and the generation of reactive oxygen species (ROS). We investigated the role of the metabolic burst in antibody-dependent cell-mediated cytotoxicity (ADCC) by human monocytes toward anti-D coated erythrocyte target cells because recent studies suggested a role for oxygen-dependent bactericidal mechanisms in ADCC. In normal monocytes, we found that ADCC was nearly halved under hypoxic conditions. Several agents known to impair activation of the burst, such as vincristine, cation chelators, and a sulfhydryl reagent, all decreased cytotoxicity if added before initiation of contact between target and effector cells. Cytotoxicity was inhibited by 2-deoxyglucose but not fluoride, suggesting a nonglycolytic role for glucose in ADCC, perhaps in the HMPS pathway. Although these data suggested a role for the metabolic burst in ADCC, scavengers of ROS did not impair cytotoxicity, and monocytes from chronic granulomatous disease (CGD) patients who had a defective metabolic burst had normal levels of ADCC. We conclude that ADCC toward anti-D coated erythrocyte target cells was the result of at least two independent but closely related cytotoxic pathways. Although one of these pathways appeared to involve the metabolic burst, the potentially cytotoxic reactive oxygen species did not appear to play a role in this system.  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