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   5608篇
  免费   532篇
  国内免费   214篇
耳鼻咽喉   42篇
儿科学   128篇
妇产科学   247篇
基础医学   707篇
口腔科学   72篇
临床医学   659篇
内科学   1091篇
皮肤病学   101篇
神经病学   432篇
特种医学   378篇
外科学   736篇
综合类   141篇
预防医学   327篇
眼科学   103篇
药学   502篇
中国医学   27篇
肿瘤学   661篇
  2023年   32篇
  2022年   53篇
  2021年   129篇
  2020年   100篇
  2019年   179篇
  2018年   184篇
  2017年   124篇
  2016年   144篇
  2015年   189篇
  2014年   216篇
  2013年   332篇
  2012年   372篇
  2011年   381篇
  2010年   260篇
  2009年   207篇
  2008年   290篇
  2007年   386篇
  2006年   265篇
  2005年   283篇
  2004年   250篇
  2003年   215篇
  2002年   209篇
  2001年   188篇
  2000年   154篇
  1999年   154篇
  1998年   62篇
  1997年   65篇
  1996年   53篇
  1995年   35篇
  1994年   35篇
  1993年   44篇
  1992年   91篇
  1991年   98篇
  1990年   62篇
  1989年   64篇
  1988年   56篇
  1987年   52篇
  1986年   46篇
  1985年   50篇
  1984年   41篇
  1983年   24篇
  1982年   21篇
  1981年   15篇
  1980年   15篇
  1979年   13篇
  1978年   18篇
  1977年   14篇
  1975年   12篇
  1974年   11篇
  1969年   9篇
排序方式: 共有6354条查询结果,搜索用时 15 毫秒
41.
42.
43.
The term of "cloacogenic anal carcinoma", "cloacogenic zone" and "cloacal membrane" have been widely used, but the term of "inflammatory cloacogenic polyp" (ICP) was first applied and published by Lobert PF and Henry DA in 1981. Here we present three cases of ICP to stress its inflammatory property, predilection to invade cloacogenic zone of anus and polypoid shape, and to differentiate it from its related lesions as concise as possible.  相似文献   
44.
Among 105 tibial shaft aseptic nonunions followed for a mean of 32 months, 30 were treated with dynamic compression plating and 75 were treated with either Küntscher or Grosse-Kempf interlocking intramedullary nailing. With the plating technique, the union rate was 90.0% (27/30), the period of time to union was 5.2 +/- 1.7 months, the complication rate was 16.7% (5/30), the infection rate was 13.3% (4/30), and the surgical time was 110 +/- 30 minutes. With the intramedullary nailing technique, the union rate was 93.3% (70/75), the period of time to union was 5.0 +/- 1.6 months, the complication rate was 17.3% (13/75), the infection rate was 13.3% (10/75), and the surgical time was 70 +/- 30 minutes. Thus, while the union rate was high with both techniques, the complication rate also was high, especially deep infection. However, the technique for nailing was simpler and required less surgical time than plating (p less than 0.001). With open reamed intramedullary nailing, a higher infection rate was noted in the cases initially treated with an external fixator than for cases in which other forms of treatment initially were used (p less than 0.05).  相似文献   
45.
Headspace solid-phase microextraction coupled with gas chromatography/flame ionization detection was developed to measure urinary methyl ethyl ketone (MEK). A fused silica fiber coated with 75 microns carboxen/polydimethylsiloxane was used to extract urinary MEK. The optimal extraction conditions were obtained when temperature was 50 degrees C, extraction time was 15 minutes, and ammonium sulfate concentration was 0.5 g/mL. The optimal desorption temperature and time were 200 degrees C and 5 minutes, respectively. The concentration range of calibration curves was 27 to 8000 ng/mL of MEK. The within-day and between-day pooled coefficients of variation (9 concentrations, triplicate samples) were 5.4% and 8.8%, respectively. The limit of detection and limit of quantitation were 4.2 ng/mL and 21.6 ng/mL, respectively. The recovery (+/- standard deviation) of MEK was 100.2% +/- 8.6% (n = 3). MEK in urine was stable for at least 1 month when stored at -20 degrees C. This method proved to be applicable for the analysis of urinary MEK of exposed workers in a plastic material printing plant. We concluded that this new method is sensitive, inexpensive, simple, and reliable for measuring the occupational exposure of MEK.  相似文献   
46.
47.
An 83-year-old man with testicular lymphoma demonstrated progressive scrotal enlargement with non-homogeneity sonographically and abnormally increased uptake in the scrotum of Tc-99m HMDP and Tc-99m MIBI scintigraphically. Extensive bone/bone marrow metastases were exhibited by Tc-99m MIBI and Tc-99m HMDP scintigraphies and MRI of the spine. In addition, focal/tubular activity of the femoral bone marrow on Tc-99m MIBI imaging was consistent with skeletal scintigraphic findings. It is emphasized that Tc-99m MIBI total body imaging enabled the demonstration of testicular lymphoma as increased uptake and the illustration of skeletal/bone marrow metastases as diffuse and/or focal increased uptake, especially focal/tubular MIBI activity of the femoral marrow.  相似文献   
48.
This 29-year-old man with cerebral palsy complicated by generalized dystonia was treated by simultaneous bilateral posteroventral pallidotomy. Postoperatively, there was slow, but steady, improvement in the patient's dystonia and disability. However, the improvement in abnormal movements was only prominent for cervical dystonia and oromandibular dyskinesia. The patient's Burke-Fahn-Marsden dystonia scores were 51 preoperatively and 37, 33.5 and 33.5, at 3, 6, and 12 months postoperatively, respectively, demonstrating a maximum improvement of 34%. These results suggest that pallidotomy can be an alternative therapy for those patients suffering from intractable generalized dystonia.  相似文献   
49.
The authors report a 61-year-old man with chronic viral encephalitis and Koshevnikov syndrome occurring 42 months after initial symptom of right hemiparesis. Serial computed tomography of the brain showed changes in the attenuation of the left temporal lobe lesion over time. Magnetic resonance images of the brain showed enlargement of left temporoparietooccipital lobes with cortical gyral enhancement on T1-weighted images following intravenous administration of gadolinium-DTPA. 99mTc-HMPAO single-photon emission computerized tomography showed increased radioactivity and hyperperfusion in the left temporoparietal region with paradoxically decreased local tissue perfusion at the contralateral right hemisphere. Follow-up magnetic resonance images of the brain 4 years later showed atrophy of bilateral cerebral hemispheres. We postulate that a "transcallosal diaschisis" with subsequent degeneration is a possible mechanism. A brain biopsy from the left temporal lobe lesion showed pictures compatible with viral encephalitis probably herpes simplex encephalitis.  相似文献   
50.
Chen CH  Niu CC  Yang WE  Chen WJ  Shih CH 《Orthopedics》1999,22(12):1177-1179
  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