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   732913篇
  免费   53021篇
  国内免费   3201篇
耳鼻咽喉   9433篇
儿科学   23615篇
妇产科学   17802篇
基础医学   113113篇
口腔科学   20668篇
临床医学   67230篇
内科学   137825篇
皮肤病学   16423篇
神经病学   50633篇
特种医学   26802篇
外国民族医学   86篇
外科学   107110篇
综合类   21049篇
现状与发展   9篇
一般理论   161篇
预防医学   54235篇
眼科学   16921篇
药学   56984篇
  46篇
中国医学   4321篇
肿瘤学   44669篇
  2021年   6877篇
  2019年   6210篇
  2018年   8725篇
  2017年   7047篇
  2016年   7589篇
  2015年   8821篇
  2014年   11908篇
  2013年   17024篇
  2012年   23182篇
  2011年   24276篇
  2010年   14891篇
  2009年   13623篇
  2008年   21959篇
  2007年   23237篇
  2006年   23450篇
  2005年   21855篇
  2004年   21010篇
  2003年   19821篇
  2002年   19152篇
  2001年   36864篇
  2000年   37304篇
  1999年   30691篇
  1998年   8056篇
  1997年   6813篇
  1996年   7110篇
  1995年   6760篇
  1994年   6221篇
  1992年   23043篇
  1991年   22989篇
  1990年   22360篇
  1989年   22109篇
  1988年   20060篇
  1987年   19440篇
  1986年   18479篇
  1985年   17317篇
  1984年   12699篇
  1983年   10745篇
  1982年   5924篇
  1979年   11520篇
  1978年   8128篇
  1977年   6833篇
  1976年   6594篇
  1975年   7270篇
  1974年   8498篇
  1973年   8144篇
  1972年   7658篇
  1971年   7127篇
  1970年   6878篇
  1969年   6307篇
  1968年   5780篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security.  相似文献   
82.
Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism.  相似文献   
83.

Aims

To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.

Materials and methods

The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.

Results

In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).

Conclusions

We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis.  相似文献   
84.
85.
目的 前瞻性评估T1~T2期乳腺癌保乳术后化疗后程大分割放疗的不良反应和耐受性,以及在缩短治疗时间、减轻患者经济负担等方面的价值。方法 共入组20例T1~T2期乳腺癌保乳术后患者,所有患者于末次多西他赛化疗前开始大分割放疗。观察急性放射反应、治疗完成率及无病生存率、住院时间及住院费用等。结果 治疗完成率100%。主要不良反应为血液学毒性(白细胞减少)及皮肤反应,患者均可耐受。中位随访时间为30.1个月,随访率100%。美容效果良好率100%。平均总治疗时间为4周,总住院治疗费用节省约1万元。21个月无病生存率为100%。结论 T1~T2期乳腺癌保乳术后可耐受同步大分割放化疗,局部控制好,美容效果佳,且具有较高的卫生经济学价值。  相似文献   
86.
87.
Neutrophils can form neutrophil extracellular traps (NETs) to capture microbes and facilitate their clearance. NETs consist of decondensed chromatin decorated with anti-microbial proteins. Here, we describe the effect of neutrophil proteases on the protein content of NETs. We show that the neutrophil serine proteases degrade several neutrophil proteins associated with NETs. Interestingly, the anti-bacterial proteins associated with NETs, such as myeloperoxidase, calgranulin B and neutrophil elastase (NE), seem to be less susceptible to proteolytic degradation than other NET proteins, such as actin and MNDA. NETs have been proposed to play a role in autoimmune reactions. Our data demonstrate that a large number of the autoepitopes of NET proteins that are recognized by autoantibodies produced by systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) patients are also removed by the proteases. In conclusion, neutrophil serine proteases have a major impact on the NET proteome and the proteolytic changes of NET-associated proteins may counteract autoimmune reactions to NET components.  相似文献   
88.
89.
90.
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