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   46651篇
  免费   3829篇
  国内免费   137篇
耳鼻咽喉   610篇
儿科学   1170篇
妇产科学   619篇
基础医学   5886篇
口腔科学   504篇
临床医学   4899篇
内科学   9331篇
皮肤病学   517篇
神经病学   4595篇
特种医学   1814篇
外科学   8868篇
综合类   498篇
现状与发展   1篇
一般理论   60篇
预防医学   3907篇
眼科学   970篇
药学   3010篇
中国医学   37篇
肿瘤学   3321篇
  2024年   52篇
  2023年   447篇
  2022年   711篇
  2021年   2089篇
  2020年   1081篇
  2019年   1737篇
  2018年   2084篇
  2017年   1464篇
  2016年   1485篇
  2015年   1638篇
  2014年   2369篇
  2013年   2798篇
  2012年   4407篇
  2011年   4312篇
  2010年   2266篇
  2009年   1903篇
  2008年   3029篇
  2007年   3140篇
  2006年   2628篇
  2005年   2354篇
  2004年   2075篇
  2003年   1761篇
  2002年   1526篇
  2001年   201篇
  2000年   201篇
  1999年   224篇
  1998年   282篇
  1997年   224篇
  1996年   162篇
  1995年   140篇
  1994年   128篇
  1993年   89篇
  1992年   100篇
  1991年   93篇
  1990年   81篇
  1989年   87篇
  1988年   89篇
  1987年   86篇
  1986年   84篇
  1985年   82篇
  1984年   67篇
  1983年   64篇
  1982年   66篇
  1981年   45篇
  1980年   54篇
  1979年   62篇
  1978年   48篇
  1976年   59篇
  1975年   40篇
  1974年   47篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
991.
992.
993.
Murine gammaherpesvirus 68 (MHV68) is a natural rodent pathogen that has been used as a model to study the pathogenesis of human gammaherpesviruses. Like other herpesviruses, MHV68 causes acute infection and establishes life-long latency in the host. Recently, it has been shown that mice latently infected with MHV68 have resistance to unrelated pathogens in secondary infection models. We therefore hypothesized that latent MHV68 infection could modulate the host response to influenza A virus. To test this hypothesis, mice were infected intranasally with influenza virus following the establishment of MHV68 latency. Mice latently infected with MHV68 showed significantly higher survival to influenza A virus infection than did PBS mock-infected mice. Latent MHV68 infection led to lower influenza viral loads and decreased inflammatory pathology in the lungs. Alveolar macrophages of mice latently infected with MHV68 showed activated status, and adoptive transfer of those activated macrophages into mice followed the infection with influenza A virus had significantly greater survival rates than control mice, suggesting that activated alveolar macrophages are a key mechanistic component in protection from secondary infections.  相似文献   
994.
995.
BackgroundPatients with depression are more susceptible to cardiovascular illness including vascular surgeries. However, health outcomes after vascular surgery among patients with depression is unknown. This study aimed to investigate associations of depression with post-operative health outcomes for vascular surgical patients.MethodsA retrospective observational study was conducted using data from a large mental healthcare provider and linked national hospitalization data for the same south London geographic catchment. OPCS-4 codes were used to identify vascular procedures. Health outcomes were compared between those with/without depression including length of hospital stay (LOS), inpatient mortality, and 30 day emergency hospital readmissions. Predictors of these health outcomes were also assessed.ResultsVascular surgery was received by 9,267 patients, including 446 diagnosed with depression. Patients with depression had a higher risk of emergency admission for vascular surgery (odds ratio [OR] 1.28; 1.03, 1.59), longer index LOS (IRR 1.38; 1.33–1.42), and a higher risk of 30-day emergency readmission (OR 1.82; 1.35–2.47). Patients with depression had higher inpatient mortality after adjustment for sociodemographic status (1.51; 1.03, 2.23) but not on full adjustment, and had longer emergency readmission LOS (1.13; 1.04, 1.22) after adjustment for sociodemographic factors and cardiovascular disease. Correlates of vascular surgery hospitalization among patients with depression included admission through emergency route for longer LOS, inpatient mortality, and 30-day hospital readmission.ConclusionPatients with depression undergoing vascular surgery have substantially poorer health outcomes. Screening for depression prior to surgery might be indicated to target preventative measures.  相似文献   
996.
BackgroundThere is evidence that anterior laxity may be affected by knee extensor open kinetic chain (OKC) exercise with responses being load-dependent. The aim of this study is to evaluate the immediate and short-term changes in passive knee anterior laxity following a single session of OKC knee extensor exercise.MethodsThirty two participants were randomly allocated to perform either high load (20 sets of 2 repetitions) or low load (2 sets of 20 repetitions) knee extensor OKC exercise with knee anterior laxity assessed before exercise, immediately after exercise and 45 and 90 min after exercise with a KT-2000 arthrometer using a 133 N force.ResultsA significant effect of time was observed on knee laxity (p < 0.001). However, a significant interaction of time and group was not found (p = 0.54) and so the results presented here are for the combined (low and high load) group mean ± standard deviation knee anterior laxity (mm) in the exercised leg: 7.2 ± 2.2 (baseline), 8.2 ± 2.3 (immediate post exercise, 14% change from baseline), 8.1 ± 2.3 (45 min post exercise, 12% change from baseline), and 7.7 ± 2.2/0.29 (6.9) (90 min post exercise, 7% change from baseline).ConclusionOKC knee extensor exercise at high loads and low loads causes an immediate increase in knee laxity that begins to decrease within 90 min.  相似文献   
997.
Neurological Sciences - Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major dose-limiting side effect of many anti-cancer agents, including taxanes, platinums, vinca alkaloids,...  相似文献   
998.

On May 3, 2016, mandatory evacuation order was declared for Fort McMurray region as wildfire threatened. Over 90,000 residents were evacuated and firefighters from Canada and abroad worked constantly to protect the municipality. Overall, fire consumed about 2400 homes and over 200,000 ha of forest, reaching into Saskatchewan. The evacuation order was lifted with residents returning to the Municipality in phases from June 1, 2016. The aim of this study is to assess likely prevalence of PTSD in residents of Fort McMurray 6 months after a wildfire and to determine the predictors of likely PTSD in the respondents. A quantitative cross-sectional survey was used to collect data through self-administered paper-based questionnaires to determine likely PTSD. The PTSD Checklist for DSM 5 Part 3 was used to assess the presence or absence of likely PTSD in respondents randomly selected from a variety of natural settings in Fort McMurray. Data were analyzed with SPSS version 20 using univariate analysis with the chi-squared test and binary logistic regression analysis. One-month prevalence rate among adult residents for likely PTSD 6 months after the disaster was 12.8% (14.9% for females and 8.7% for males). While controlling for other factors in the logistic regression model, corresponding odds ratios included 9.51 and 4.88 for those who received no or only limited support respectively from friends/family, 8.00 for those who had history of an anxiety disorder before the wildfire, and 4.01 for those who received counseling after the wildfire. Respondents who presented with likely PTSD were significantly more likely to self-report increased drug abuse, but not increased alcohol use, after the fire. Our study has established that while support from family/friends following wildfires may be protective against likely PTSD, a prior diagnosis of an anxiety disorder significantly increased risk for developing PTSD. Further studies are needed to explore whether receiving counseling after a wild fire alters the likelihood of individuals presenting with PTSD.

  相似文献   
999.
This multicenter study evaluated the accuracy of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry identifications from the VITEK MS system (bioMérieux, Marcy l’Etoile, France) for Enterobacteriaceae typically encountered in the clinical laboratory. Enterobacteriaceae isolates (n?=?965) representing 17 genera and 40 species were analyzed on the VITEK MS system (database v2.0), in accordance with the manufacturer’s instructions. Colony growth (≤72 h) was applied directly to the target slide. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry before mass spectrometry analysis. On the basis of the confidence level, the VITEK MS system provided a species, genus only, or no identification for each isolate. The accuracy of the mass spectrometric identification was compared to 16S rRNA gene sequencing performed at MIDI Labs (Newark, DE). Supplemental phenotypic testing was performed at bioMérieux when necessary. The VITEK MS result agreed with the reference method identification for 96.7 % of the 965 isolates tested, with 83.8 % correct to the species level and 12.8 % limited to a genus-level identification. There was no identification for 1.7 % of the isolates. The VITEK MS system misidentified 7 isolates (0.7 %) as different genera. Three Pantoea agglomerans isolates were misidentified as Enterobacter spp. and single isolates of Enterobacter cancerogenus, Escherichia hermannii, Hafnia alvei, and Raoultella ornithinolytica were misidentified as Klebsiella oxytoca, Citrobacter koseri, Obesumbacterium proteus, and Enterobacter aerogenes, respectively. Eight isolates (0.8 %) were misidentified as a different species in the correct genus. The VITEK MS system provides reliable mass spectrometric identifications for Enterobacteriaceae.  相似文献   
1000.
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