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   268830篇
  免费   53815篇
  国内免费   611篇
耳鼻咽喉   3992篇
儿科学   10158篇
妇产科学   4840篇
基础医学   41249篇
口腔科学   13811篇
临床医学   26448篇
内科学   67563篇
皮肤病学   11890篇
神经病学   29534篇
特种医学   8413篇
外国民族医学   26篇
外科学   38315篇
综合类   1515篇
现状与发展   1篇
一般理论   88篇
预防医学   23410篇
眼科学   4765篇
药学   17211篇
中国医学   1769篇
肿瘤学   18258篇
  2023年   1084篇
  2022年   2376篇
  2021年   5581篇
  2020年   7600篇
  2019年   14261篇
  2018年   15176篇
  2017年   14979篇
  2016年   15545篇
  2015年   16088篇
  2014年   17729篇
  2013年   19995篇
  2012年   16772篇
  2011年   17367篇
  2010年   15605篇
  2009年   11318篇
  2008年   12578篇
  2007年   12098篇
  2006年   11301篇
  2005年   11382篇
  2004年   10682篇
  2003年   9736篇
  2002年   7799篇
  2001年   5998篇
  2000年   5820篇
  1999年   4838篇
  1998年   1817篇
  1997年   1495篇
  1996年   1475篇
  1995年   1250篇
  1994年   1223篇
  1993年   1083篇
  1992年   2790篇
  1991年   2684篇
  1990年   2458篇
  1989年   2439篇
  1988年   2193篇
  1987年   2023篇
  1986年   1894篇
  1985年   1810篇
  1984年   1350篇
  1983年   1072篇
  1982年   642篇
  1981年   563篇
  1980年   520篇
  1979年   954篇
  1978年   644篇
  1977年   513篇
  1975年   568篇
  1974年   568篇
  1973年   573篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
A classic pilomatricoma, which usually presents with an asymptomatic, solitary, firm, subcutaneous nodule in the head, neck, or extremities of the paediatric population, is easily diagnosed based on its characteristic clinical and histopathological features. However, its variants often pose particular diagnostic challenges to clinicians due to their rarity and diverse clinicopathological features. We present a new pseudocystic variant, manifesting as solid lesions floating in a fluid‐filled sac.  相似文献   
53.
54.
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   
55.
56.
57.
58.
59.
Porocarcinoma is an unusual, locally aggressive and potentially fatal neoplasm. Several cutaneous malignancies have been described in association with porocarcinoma, including squamous cell carcinoma, basal cell carcinoma and tricholemmal carcinoma. Previous reports have indicated that the occurrence of malignant tumours in combination with porocarcinoma is extremely rare, in particular with regard to Bowen disease (BD). We report an uncommon case of porocarcinoma occurring synchronously in a single BD lesion in a 63‐year‐old woman with multiple BD lesions. The clinical and histological findings confirmed this diagnosis.  相似文献   
60.
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.  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