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   188917篇
  免费   13385篇
  国内免费   2970篇
耳鼻咽喉   2882篇
儿科学   3138篇
妇产科学   3395篇
基础医学   28331篇
口腔科学   4130篇
临床医学   18877篇
内科学   34009篇
皮肤病学   5471篇
神经病学   14979篇
特种医学   9549篇
外国民族医学   17篇
外科学   23673篇
综合类   5249篇
现状与发展   8篇
一般理论   45篇
预防医学   11417篇
眼科学   4761篇
药学   17153篇
  23篇
中国医学   3160篇
肿瘤学   15005篇
  2023年   1197篇
  2022年   3225篇
  2021年   6377篇
  2020年   3509篇
  2019年   4557篇
  2018年   5485篇
  2017年   4476篇
  2016年   5429篇
  2015年   7513篇
  2014年   9043篇
  2013年   10419篇
  2012年   15438篇
  2011年   14995篇
  2010年   8810篇
  2009年   7401篇
  2008年   10647篇
  2007年   10353篇
  2006年   9576篇
  2005年   9059篇
  2004年   7729篇
  2003年   6889篇
  2002年   6037篇
  2001年   4826篇
  2000年   4470篇
  1999年   3619篇
  1998年   1661篇
  1997年   1365篇
  1996年   1099篇
  1995年   1017篇
  1994年   872篇
  1993年   768篇
  1992年   1651篇
  1991年   1580篇
  1990年   1374篇
  1989年   1292篇
  1988年   1223篇
  1987年   1182篇
  1986年   938篇
  1985年   974篇
  1984年   729篇
  1983年   557篇
  1982年   395篇
  1981年   415篇
  1980年   343篇
  1979年   549篇
  1978年   439篇
  1977年   317篇
  1976年   306篇
  1974年   348篇
  1973年   360篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
21.
22.
23.
This study investigated the hypocholesterolaemic effects of bitter melon aqueous extracts (BMAE) in vitro, the inhibitory effects of BMAE on pancreatic cholesterol esterase (CEase) and incorporation of cholesterol into micelles were investigated. BMAE decreased the in vitro micellar solubility of cholesterol in a dose-dependent manner. The conformation of CEase was investigated by means of circular dichroism (CD) and fluorescence. The result revealed the decrease of α-helix contents, increase of β-sheet and exposure of aromatic amino acid residuals. The incorporation of cholesterol into micelles was inhibited by BMAE. A complex was observed by transmission electron microscopy (TEM), which indicated interaction between cholesterol and BMAE. The result revealed that BMAE can play a role in decreased intestinal cholesterol absorption via inhibition of CEase, and of micelle formation.  相似文献   
24.
25.
The identification of EGFR mutations in non‐small‐cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre‐operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro‐dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one of the corresponding pre‐operative, cytological specimens. Several (18.4%) analyses of the pre‐operative biopsies were inconclusive, especially in case of biopsies undergoing LMD and regarding exon 21 analysis. Discrepancy of mutation status in one patient may reflect intra‐tumoural heterogeneity or technical issues. Moreover, several inconclusive results in the diagnostic biopsies reveal that attention must be paid on the suitability of pre‐operative biopsies for EGFR mutation analysis.  相似文献   
26.
A 48-year-old smoker with a history of hyperthyroidism treated 10 years prior to presentation with radioactive iodine ablation of the thyroid gland presented to his ophthalmologist with a 2-week history of transient loss of vision in the right eye occurring for 1 to 2 hours each morning. He denied ocular pain, diplopia or change in the prominence of one or both eyes. Examination revealed 2 mm of relative proptosis on the right, bilateral temporal flare and lower lid retraction. There was minimal upper lid retraction and no evidence of lid lag. Ocular motility was full. Dilated fundoscopic examination revealed bilateral optic nerve edema, right more than left. CT of the orbit demonstrated enlargement of the extraocular muscles bilaterally with marked enlargement of the right medial rectus and left inferior rectus muscles resulting in crowding at the orbital apex bilaterally. Laboratory testing revealed the patient to be hyperthyroid. The patient was treated with high dose oral steroids followed by orbital radiation. Hyperthyroidism was managed by the patient’s primary care physician. Visual symptoms rapidly improved with oral steroids and orbital radiation. Optic nerve edema completely resolved. Repeat CT imaging demonstrated a reduction in the enlargement of the extraocular muscles with relief of bilateral optic nerve compression.  相似文献   
27.
European Journal of Orthopaedic Surgery & Traumatology - The goals of this study were to compare patient satisfaction and wound-related complications in patients receiving 2-octyl cyanoacrylate...  相似文献   
28.
Three‐dimensional (3D) printing technology, virtual reality, and augmented reality technology have been used to help surgeons to complete complex total hip arthroplasty, while their respective shortcomings limit their further application. With the development of technology, mixed reality (MR) technology has been applied to improve the success rate of complicated hip arthroplasty because of its unique advantages. We presented a case of a 59‐year‐old man with an intertrochanteric fracture in the left femur, who had received a prior left hip fusion. After admission to our hospital, a left total hip arthroplasty was performed on the patient using a combination of MR technology and 3D printing technology. Before surgery, 3D reconstruction of a certain bony landmark exposed in the surgical area was first performed. Then a veneer part was designed according to the bony landmark and connected to a reference registration landmark outside the body through a connecting rod. After that, the series of parts were made into a holistic reference registration instrument using 3D printing technology, and the patient's data for bone and surrounding tissue, along with digital 3D information of the reference registration instrument, were imported into the head‐mounted display (HMD). During the operation, the disinfected reference registration instrument was installed on the selected bony landmark, and then the automatic real‐time registration was realized by HMD through recognizing the registration landmark on the reference registration instrument, whereby the patient's virtual bone and other anatomical structures were quickly and accurately superimposed on the real body of the patient. To the best of our knowledge, this is the first report to use MR combined with 3D printing technology in total hip arthroplasty.  相似文献   
29.
30.
Synovial chondromatosis is a rare lesion in the wrist, but some cases in the distal radioulnar joint have been reported and previous case reports emphasize joint calcifications, shown on preoperative plain radiographs. We report an extremely uncommon case of synovial chondromatosis in the pisotriquetral joint, in which radiographs and magnetic resonance imaging did not demonstrate apparent calcified bodies. In our case, for the accurate diagnosis and treatment, surgical exploration of the joint and synovectomy with removal of loose bodies was performed.  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