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   2375篇
  免费   147篇
  国内免费   9篇
耳鼻咽喉   28篇
儿科学   125篇
妇产科学   71篇
基础医学   291篇
口腔科学   97篇
临床医学   217篇
内科学   515篇
皮肤病学   78篇
神经病学   178篇
特种医学   60篇
外国民族医学   2篇
外科学   315篇
综合类   15篇
预防医学   142篇
眼科学   31篇
药学   167篇
中国医学   2篇
肿瘤学   197篇
  2023年   22篇
  2022年   30篇
  2021年   61篇
  2020年   49篇
  2019年   73篇
  2018年   79篇
  2017年   56篇
  2016年   73篇
  2015年   67篇
  2014年   91篇
  2013年   138篇
  2012年   192篇
  2011年   176篇
  2010年   86篇
  2009年   89篇
  2008年   163篇
  2007年   157篇
  2006年   154篇
  2005年   138篇
  2004年   116篇
  2003年   110篇
  2002年   113篇
  2001年   27篇
  2000年   10篇
  1999年   19篇
  1998年   30篇
  1997年   20篇
  1996年   24篇
  1995年   8篇
  1994年   18篇
  1993年   18篇
  1992年   11篇
  1991年   13篇
  1990年   10篇
  1989年   9篇
  1988年   8篇
  1987年   7篇
  1986年   4篇
  1985年   11篇
  1984年   6篇
  1983年   9篇
  1982年   7篇
  1981年   4篇
  1979年   2篇
  1978年   4篇
  1977年   4篇
  1974年   4篇
  1967年   2篇
  1964年   1篇
  1963年   2篇
排序方式: 共有2531条查询结果,搜索用时 15 毫秒
91.

Background

New HIV infections in Tanzania have been decreasing, however some populations remain at higher risk. Despite of that, evidence on the magnitude of HIV infection and the associated factors and HIV/AIDS services uptake among fisherfolk in Tanzania are inadequately explored. This study therefore aimed at determining prevalence of HIV infection and utilization of HIV/AIDS services among fishfolk in selected Islands of Lake Victoria for evidence-based interventions.

Methods

Cross-sectional study determining status of HIV infection among fisherfolk (n?=?456) and retrospective review of voluntary counselling and testing (VCT) registry (n?=?1744) were done in Buchosa and Muleba districts. Structured questionnaire and HIV rapid test kits with the standard testing protocol were used as research tools.

Results

A total of 269 (58.9%) male and 187 (41.1%) female fisherfolk were recruited during the community survey. Prevalence of HIV infection was 14% in all surveyed landing sites with a site variation from as low as 7.2% to as high as 23.8%. Participants employed in fishing related employment had higher odds of being HIV infected (5.4 times) than those who practiced fishing and partly farming [OR?=?5.40; 95%CI 1.88–15.61; p?<?0.001]. Participants employed in fishing related employment had higher odds of being HIV infected (5.4 times) than those practiced fishing and farming [OR?=?5.40; 95%CI 1.88–15.61; P?<?0.001]. Lack of formal education [aOR?=?3.37; 95%CI 1.64–6.92; p?<?0.001], being older [aOR?=?1.06; 95%CI 1.03–1.09] and using alcohol [aOR?=?2.26; 95%CI 1.23–4.15] predicted the likelihood of contracting HIV infection. Approximately three quarters (76%) of respondents had ever tested for HIV infection within past 1 year. Moreover, about half of the study participants had used condom inconsistently and 5 out of 14 (37.5%) of participants who knew their status had never started treatment. Despite the low uptake of most HIV preventive services, majority (88%) of male fisherfolk were circumcised.

Conclusion

The magnitude of HIV infection among fisherfolk was up to 3 times higher than that of the general populations in Muleba and Buchosa districts. Higher age, using alcohol and lack of formal education predicted increased likelihood of HIV infection. The uptake of key HIV/AIDS curative and preventive services was generally low.
  相似文献   
92.
93.
94.
95.
Abnormal lung function in healthy preterm infants.   总被引:4,自引:0,他引:4  
The aim of this study was to assess the consequences of preterm birth for the functional development of the lungs. We studied 32 healthy preterm infants (gestational age 25 to 33 wk at birth) and 53 healthy full-term infants (37 to 42 wk) at the same mean postmenstrual age of 40 wk with a multibreath nitrogen washout technique to assess functional residual capacity (FRC), gas mixing efficiency, and dead space and with the single-breath occlusion technique to calculate compliance and resistance of the respiratory system. Twenty of the preterm infants were also assessed with the same methods at 34.2 (32 to 37) wk. At the same postmenstrual age the preterm infants had lower FRC/kg body weight, lower specific compliance, impaired gas mixing efficiency, and higher total and dead space ventilation/kg than the full-term infants. Specific compliance and specific conductance decreased but gas mixing efficiency increased from 34 to 40 wk. We conclude that premature exposure to extrauterine conditions changes lung function. Preterm infants showed signs of dysfunction of the terminal respiratory units and higher elastic recoil than infants who spent the corresponding time for development in utero. It is suggested that preterm birth per se affects alveolarization and formation of elastic tissue in the lungs.  相似文献   
96.
97.
Seven patients were operated on for thoracic (n=2) or thoracoabdominal (n=5) aortic aneurysms during cross-clamping of the aorta. Interstitial tissue fluid pressure was measured at the neck during cross-clamping of the descending thoracic aorta by the wick-in-needle technique, whereas control measurements were obtained prior to cross-clamping. The subcutaneous interstitial fluid pressure was significantly higher on the neck during cross-clamping of the thoracic aorta compared with control measurements (median 3.7 mmHg vs –0.6 mmHg, p<0.05). Increased subcutaneous interstitial tissue pressure of the upper part of the body is probably caused by increased capillary filtration rate induced by inhibited autoregulatory functions during aortic cross-clamping. The pressure measurements objectively confirm the problem of edema formation of the head and neck during these operations. The edema may occasionally affect the upper airways and represent a problem for intubation of the patient in the postoperative phase.  相似文献   
98.
99.
Mantle cell lymphoma (MCL) is believed to originate from a naive B cell. However, we recently demonstrated that a subset of MCL displayed mutated V(H) genes. We also reported restricted use of certain V(H) genes. To assess the prognostic impact of these new findings, we performed V(H) gene analysis of 110 patients, revealing that 18 (16%) patients had mutated and 92 (84%) patients had unmutated V(H) genes. Because the mutation rate was low in the mutated group (2.2%-6.7%), further investigation of the germline V(H) gene in T cells from 5 patients with mutated V(H) genes was carried out; results showed that the unrearranged V(H) gene was identical to the published sequence. These data confirm that the base pair substitutions within the rearranged V(H) genes represent hypermutations, and indicate germinal center exposure. However, V(H) gene mutation status did not correlate with prognosis because there was no difference in clinical outcome between the unmutated and mutated groups. The most frequently used V(H) genes were V(H)3-21 (21 patients) and V(H)4-34 (19 patients). A novel finding was that V(H)3-21(+) MCL almost exclusively expressed lambda light chains and displayed highly restricted use of the V(lambda)3-19 gene. V(H)3-21(+) patients had longer median survival than the remaining patients (53 vs 34 months; P =.03), but they tended to be younger at diagnosis. The combined use of V(H)3-21/V(lambda)3-19 suggests a possible role for antigen(s) in the pathogenesis of these tumors and indicates that V(H)3-21(+) patients constitute a new MCL entity.  相似文献   
100.
Using an integrative approach in which genetic variation, gene expression, and clinical phenotypes are assessed in relevant tissues may help functionally characterize the contribution of genetics to disease susceptibility. We sought to identify genetic variation influencing skeletal muscle gene expression (expression quantitative trait loci [eQTLs]) as well as expression associated with measures of insulin sensitivity. We investigated associations of 3,799,401 genetic variants in expression of >7,000 genes from three cohorts (n = 104). We identified 287 genes with cis-acting eQTLs (false discovery rate [FDR] <5%; P < 1.96 × 10−5) and 49 expression–insulin sensitivity phenotype associations (i.e., fasting insulin, homeostasis model assessment–insulin resistance, and BMI) (FDR <5%; P = 1.34 × 10−4). One of these associations, fasting insulin/phosphofructokinase (PFKM), overlaps with an eQTL. Furthermore, the expression of PFKM, a rate-limiting enzyme in glycolysis, was nominally associated with glucose uptake in skeletal muscle (P = 0.026; n = 42) and overexpressed (Bonferroni-corrected P = 0.03) in skeletal muscle of patients with T2D (n = 102) compared with normoglycemic controls (n = 87). The PFKM eQTL (rs4547172; P = 7.69 × 10−6) was nominally associated with glucose uptake, glucose oxidation rate, intramuscular triglyceride content, and metabolic flexibility (P = 0.016–0.048; n = 178). We explored eQTL results using published data from genome-wide association studies (DIAGRAM and MAGIC), and a proxy for the PFKM eQTL (rs11168327; r2 = 0.75) was nominally associated with T2D (DIAGRAM P = 2.7 × 10−3). Taken together, our analysis highlights PFKM as a potential regulator of skeletal muscle insulin sensitivity.  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