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   26634篇
  免费   1536篇
  国内免费   126篇
耳鼻咽喉   361篇
儿科学   715篇
妇产科学   498篇
基础医学   3816篇
口腔科学   2276篇
临床医学   2003篇
内科学   5559篇
皮肤病学   619篇
神经病学   2074篇
特种医学   473篇
外国民族医学   2篇
外科学   2773篇
综合类   172篇
一般理论   7篇
预防医学   3526篇
眼科学   356篇
药学   1777篇
中国医学   245篇
肿瘤学   1044篇
  2023年   224篇
  2022年   520篇
  2021年   1039篇
  2020年   703篇
  2019年   828篇
  2018年   1012篇
  2017年   699篇
  2016年   772篇
  2015年   870篇
  2014年   1240篇
  2013年   1463篇
  2012年   2218篇
  2011年   2422篇
  2010年   1172篇
  2009年   868篇
  2008年   1655篇
  2007年   1652篇
  2006年   1338篇
  2005年   1193篇
  2004年   1103篇
  2003年   1030篇
  2002年   869篇
  2001年   389篇
  2000年   357篇
  1999年   309篇
  1998年   151篇
  1997年   92篇
  1996年   73篇
  1995年   78篇
  1994年   87篇
  1993年   61篇
  1992年   150篇
  1991年   119篇
  1990年   141篇
  1989年   130篇
  1988年   117篇
  1987年   74篇
  1986年   87篇
  1985年   76篇
  1984年   52篇
  1983年   43篇
  1979年   65篇
  1974年   39篇
  1973年   45篇
  1970年   59篇
  1969年   77篇
  1968年   49篇
  1967年   53篇
  1966年   49篇
  1965年   36篇
排序方式: 共有10000条查询结果,搜索用时 36 毫秒
1.
2.
3.
Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy.  相似文献   
4.
5.
6.
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   
7.
8.
9.
10.
Classical Kaposi sarcoma (KS) usually appears on lower extremities accompanied or preceded by local lymphedema. However, the development in areas of chronic lymphedema of the arms following mastectomy, mimicking a Stewart–Treves syndrome, has rarely been described. We report an 81‐year‐old woman who developed multiple, erythematous to purple tumors, located on areas of post mastectomy lymphedema. Histopathological examination evidenced several dermal nodules formed by spindle‐shaped cells that delimitated slit‐like vascular spaces with some red cell extravasation. Immunohistochemically, the human herpesvirus type 8 (HHV‐8) latent nuclear antigen‐1 was detected in the nuclei of most tumoral cells confirming the diagnosis of KS. Lymphedema could promote the development of certain tumors by altering immunocompetence. Although angiosarcoma (AS) is the most frequent neoplasia arising in the setting of chronic lymphedema, other tumors such as benign lymphangiomatous papules (BLAP) or KS can also develop in lymphedematous limbs. It is important to establish the difference between AS and KS because their prognosis and treatment are very different. Identification by immunohistochemistry of HHV‐8 is useful for the distinction between KS and AS or BLAP.  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