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   37009篇
  免费   1363篇
  国内免费   193篇
耳鼻咽喉   369篇
儿科学   842篇
妇产科学   458篇
基础医学   4593篇
口腔科学   905篇
临床医学   2312篇
内科学   9714篇
皮肤病学   589篇
神经病学   2723篇
特种医学   1207篇
外科学   6752篇
综合类   153篇
一般理论   3篇
预防医学   1015篇
眼科学   568篇
药学   2501篇
  3篇
中国医学   143篇
肿瘤学   3715篇
  2023年   228篇
  2022年   345篇
  2021年   647篇
  2020年   374篇
  2019年   519篇
  2018年   580篇
  2017年   530篇
  2016年   564篇
  2015年   574篇
  2014年   774篇
  2013年   967篇
  2012年   1561篇
  2011年   1667篇
  2010年   1053篇
  2009年   890篇
  2008年   1634篇
  2007年   1774篇
  2006年   1782篇
  2005年   1901篇
  2004年   1777篇
  2003年   1804篇
  2002年   1801篇
  2001年   1244篇
  2000年   1315篇
  1999年   1163篇
  1998年   533篇
  1997年   387篇
  1996年   385篇
  1995年   346篇
  1994年   314篇
  1993年   341篇
  1992年   816篇
  1991年   756篇
  1990年   697篇
  1989年   756篇
  1988年   672篇
  1987年   643篇
  1986年   564篇
  1985年   538篇
  1984年   352篇
  1983年   299篇
  1979年   270篇
  1978年   189篇
  1977年   169篇
  1974年   160篇
  1973年   172篇
  1972年   166篇
  1971年   158篇
  1970年   159篇
  1969年   146篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
A head fixation system using four carbon fiber head pins and modified pin supporting devices is described. The fixation system was developed for intraoperative computed tomographic scanning and provides artifact-free images during open-field neurosurgery.  相似文献   
22.
23.
We have developed an implant heating system (IHS) for interstitial hyperthermia of brain tumors. IHS consists of three compartments: ferromagnetic implant with low Curie point, induction coil and generator to produce high frequency magnetic field. The device works as follows: It is heated up to a Curie temperature (Tc) by Eddy current under the magnetic field. Heat generated in the implant is conducted to the tumor tissue into which it has been implanted. To evaluate the effect of this hyperthermia, a brain tumor model was produced by innoculation of VX2 tumor cells and treated either by hyperthermia with IHS alone, chemotherapy with ACNU alone, or with a combination of both. The longest survival was obtained by the combined treatment, and significant prolongation of survival was found in the single treatment groups. In the Phase I clinical trial, one or several implants (1.8 mm X 15 mm, Tc = 68 degrees C) made of Fe-Pt alloy were placed in the tumor by CT guided stereotactic procedure, or manually during craniotomy. Hyperthermia of above 42 degrees C for 30 to 60 minutes twice a week was brought about in ten cases of malignant brain tumor. CT evaluation was made in nine cases treated for more than ten times in this way. Five out of the nine cases responded to this hyperthermia with irradiation. In conclusion, a safe, repeated and longterm treatment was possible without significant side effects. The hyperthermia with IHS may also be applicable to benign intracranial tumors and neoplasms in other part of body as well.  相似文献   
24.
The ultrastructural localization of adhalin and its relations to dystrophin, β-dystroglycan, and β-spectrin were studied in normal murine skeletal myofibers. The C-terminal peptides of adhalin and β-dystroglycan were synthesized based on their cDNAs, and the affinity-purified antibodies against these peptides were produced. Single-immunolabeling electron microscopy showed that the adhalin was located just inside the muscle plasma membrane or inside the myofiber a short distance from the plasma membrane. The adhalin signal was also noted at the sarcoplasmic side of plasmalemmd invaginations or at vesicular structures in subsarcolemmal areas. Double-immunogold-labeling electron microscopy disclosed a similar localization of dystrophin, β-dystroglycan, and β-spectrin. The close association of adhalin with dystrophin or β-dystroglycan was demonstrated by formation of doublets by signals of antibodies of adhalin with those of dystrophin or β-dystroglycan and was confirmed by statistical analyses. This study demonstrated that the location of adhalin is close to that of dystrophin and β-dystroglycan at the muscle plasma membrane.  相似文献   
25.
26.
A 14-year-old junior high school boy was admitted to our institute. Previously he had been diagnosed as having peripheral pulmonary stenosis (Gay's classification, type IV) at the age of 2 years and 10 months. On this occasion, however, a diagnosis of supravalvular aortic stenosis was made, with a pressure gradient of about 120 mmHg, and all examinations showed spontaneous remission of peripheral pulmonary stenosis. He underwent a successful standard aortoplasty. This is the first reported case of spontaneous remission of peripheral pulmonary stenosis.  相似文献   
27.
The absorption and excretion and clinical effectiveness of cefixime (CFIX) granules, a new oral cephalosporin, were studied with pediatric patients with tonsillitis and urinary tract infection (UTI). Peak serum concentrations in 3 children given orally a single dose of 3 mg/kg on fasting were 0.545 micrograms/ml at 2 hours in 1 patient, and 1.56 and 1.26 micrograms/ml at 4 hours in the other 2. The half-lives in the 3 patients were 3.21-3.42 hours, with an average of 3.29 hours. The urinary concentration during the first 6 hours was 36.5 micrograms/ml in 1 patient showing the low serum level, and the first 6-hour urinary recovery rate was 7.3%. In the other 2 patients, urinary concentrations and recovery rates up to 6 hours were 87 and 62 micrograms/ml, and 17.0 and 15.1%, respectively. The second 6-hour urinary concentrations and recovery rates were 35.5 and 20.8 micrograms/ml, and 12.7 and 8.8%, respectively. The urinary recovery rates up to 12 hours were 29.7 and 23.9%, respectively. CFIX was given orally to 19 children with 20 diseases in daily doses of 6.4-12.9 mg/kg in 2 or 3 divided portions for 3 to 12 days. Clinical evaluations were made on 18 diseases. Clinical effects of CFIX were excellent in 4, good in 7 and poor in 1 of the 12 patients with tonsillitis, and excellent in 5 and good in 1 of the 6 patients with UTI. The overall clinical effectiveness rate was 94.4%. No side effects were observed in any of the 19 patients. Hematological tests, showed slight elevation of blood platelet counts in 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
28.
29.
30.
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