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   1417746篇
  免费   106853篇
  国内免费   2693篇
耳鼻咽喉   19728篇
儿科学   47875篇
妇产科学   37501篇
基础医学   200990篇
口腔科学   36854篇
临床医学   124809篇
内科学   287458篇
皮肤病学   30682篇
神经病学   113930篇
特种医学   56770篇
外国民族医学   666篇
外科学   217146篇
综合类   28743篇
现状与发展   3篇
一般理论   513篇
预防医学   105878篇
眼科学   30888篇
药学   104375篇
  4篇
中国医学   2651篇
肿瘤学   79828篇
  2021年   10432篇
  2019年   11603篇
  2018年   16187篇
  2017年   12370篇
  2016年   13680篇
  2015年   15515篇
  2014年   21735篇
  2013年   32405篇
  2012年   45430篇
  2011年   48099篇
  2010年   28528篇
  2009年   27320篇
  2008年   45845篇
  2007年   49154篇
  2006年   48844篇
  2005年   48116篇
  2004年   46725篇
  2003年   45112篇
  2002年   43945篇
  2001年   65355篇
  2000年   67499篇
  1999年   57842篇
  1998年   17065篇
  1997年   15276篇
  1996年   15498篇
  1995年   14641篇
  1994年   13814篇
  1993年   12813篇
  1992年   45257篇
  1991年   44177篇
  1990年   42773篇
  1989年   40658篇
  1988年   37400篇
  1987年   36750篇
  1986年   34063篇
  1985年   32755篇
  1984年   24709篇
  1983年   20777篇
  1982年   12424篇
  1981年   11344篇
  1979年   21687篇
  1978年   15175篇
  1977年   12901篇
  1976年   12013篇
  1975年   12891篇
  1974年   14900篇
  1973年   14327篇
  1972年   13115篇
  1971年   11853篇
  1970年   11185篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Rheological behaviour of pharmaceutical semisolid preparations significantly affects manufacturing process, administration, stability, homogeneity of incorporated drug, accuracy of dosing, adhesion in the place of application, drug release, and resulting therapeutic effect of the product. We performed test of consistency by penetrometry, rotational, oscillation and creep tests, and squeeze and tack tests of model samples to introduce methods suitable for characterization and comparison of semisolids in practice. Penetrometry is a simple method allowing sorting the semisolids to low and high stress-resistant materials but deficient for rheological characterization of semisolids. Value of yield stress, generally considered to be appropriate feature of semisolids, is significantly influenced by the method of testing and the way of evaluation. The hysteresis loops of model semisolids revealed incomplete thixotropy, therefore, three-step thixotropy test was employed. Semisolids showed nonlinear response in the creep phase of tests and partial recovery of structure by storing energy in the recovery phase. Squeeze and tack tests seem to be convenient ways for comparison of semisolids. Our study can contribute to a better understanding of different flow behaviour of semisolids given by different physicochemical properties of excipients and can bring useful approaches to evaluation and comparison of semisolids in practice.  相似文献   
53.
This paper revisits a 2003 publication in Nursing Philosophy: The need for accurate perception and informed judgement in determining the appropriate use of the nursing resource: hearing the patient's voice. The author suggests that the basic ideas and focus of this 16‐year‐old paper are still topical and relevant in considerations of nursing care. However, it is also suggested that greater attention to the importance of the nurse–patient relationship in considerations of resource allocation, and potential rationing of nursing care, would have strengthened the original paper.  相似文献   
54.
55.
Phang  P. Terry 《Abdominal imaging》2019,44(11):3740-3742
Abdominal Radiology -  相似文献   
56.
57.
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   
58.
59.

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   
60.
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