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   199274篇
  免费   14770篇
  国内免费   691篇
耳鼻咽喉   2384篇
儿科学   5044篇
妇产科学   3935篇
基础医学   26630篇
口腔科学   4216篇
临床医学   19879篇
内科学   42551篇
皮肤病学   2848篇
神经病学   19474篇
特种医学   7480篇
外国民族医学   9篇
外科学   30561篇
综合类   2654篇
现状与发展   1篇
一般理论   150篇
预防医学   15618篇
眼科学   4335篇
药学   13127篇
中国医学   256篇
肿瘤学   13583篇
  2023年   880篇
  2021年   3730篇
  2020年   2188篇
  2019年   3527篇
  2018年   4283篇
  2017年   3172篇
  2016年   3665篇
  2015年   4276篇
  2014年   5962篇
  2013年   8585篇
  2012年   12771篇
  2011年   13112篇
  2010年   7528篇
  2009年   6929篇
  2008年   11998篇
  2007年   13182篇
  2006年   12399篇
  2005年   12504篇
  2004年   11918篇
  2003年   10966篇
  2002年   10934篇
  2001年   2659篇
  2000年   2328篇
  1999年   2428篇
  1998年   2488篇
  1997年   2131篇
  1996年   1762篇
  1995年   1767篇
  1994年   1478篇
  1993年   1336篇
  1992年   1680篇
  1991年   1577篇
  1990年   1438篇
  1989年   1420篇
  1988年   1279篇
  1987年   1241篇
  1986年   1260篇
  1985年   1309篇
  1984年   1341篇
  1983年   1310篇
  1982年   1494篇
  1981年   1337篇
  1980年   1227篇
  1979年   949篇
  1978年   910篇
  1977年   921篇
  1976年   763篇
  1975年   729篇
  1974年   683篇
  1973年   673篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
1.
2.
3.
International Journal of Clinical Oncology - Immune-checkpoint inhibitors (ICIs) are standard treatments for metastatic non-small cell lung cancer (NSCLC). Patients with poor performance status...  相似文献   
4.
5.
The current study explored the influence of three methods of parental emotion discourse (structured story-telling, reminiscing, and picture book) and their relation to preschoolers’ emotion understanding. Thirty-seven families participated in the study. Analyses showed that the structured story-telling method produced more emotion words, was high in unique emotion words, and was high for both emotion labelling and explanations. All three methods showed some potential to predict preschooler’s emotion understanding. Structured story-telling was best at predicting role-taking, while reminiscing and the picture book both were better at predicting situation knowledge. Additional studies are needed to further explore the influence of different methods of assessing emotion discourse to enhance validity and reliability of research in this field.  相似文献   
6.
7.
8.
9.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
10.
Coxiella burnetii is an obligate intracellular Gram-negative bacterium that causes the zoonotic disease Q fever. Although Q fever is mainly transmitted by aerosol infection, study of the immune responses in the lung following pulmonary C. burnetii infection is lacking. Neutrophils are considered the first immune cell to migrate into the lung and play an important role in host defense against aerosol infection with microbial pathogens. However, the role of neutrophils in the host defense against C. burnetii infection remains unclear. To determine the role of neutrophils in protective immunity against C. burnetii infection, the RB6-8C5 antibody was used to deplete neutrophils in mice before intranasal infection with C. burnetii. The results indicated that neutrophil-depleted mice developed more severe disease than their wild-type counterparts, suggesting that neutrophils play an important role in host defense against C. burnetii pulmonary infection. We also found that neither CXC chemokine receptor 2 (CXCR2) nor interleukin-17 (IL-17) receptor (IL-17R) deficiency changed the severity of disease following intranasal C. burnetii challenge, suggesting that keratinocyte-derived chemokine and IL-17 may not play essential roles in the response to C. burnetii infection. However, significantly higher C. burnetii genome copy numbers were detected in the lungs of IL-1R−/− mice at 14 days postinfection. This indicates that IL-1 may be important for the clearance of C. burnetii from the lungs following intranasal infection. Our results also suggest that neutrophils are involved in protecting vaccinated mice from C. burnetii challenge-induced disease. This is the first study to demonstrate an important role for neutrophils in protective immunity against C. burnetii infection.  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