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   16366篇
  免费   1366篇
  国内免费   38篇
耳鼻咽喉   191篇
儿科学   480篇
妇产科学   441篇
基础医学   2141篇
口腔科学   279篇
临床医学   1702篇
内科学   3691篇
皮肤病学   193篇
神经病学   1558篇
特种医学   602篇
外科学   2032篇
综合类   298篇
一般理论   14篇
预防医学   1851篇
眼科学   304篇
药学   1105篇
中国医学   17篇
肿瘤学   871篇
  2023年   69篇
  2022年   99篇
  2021年   272篇
  2020年   135篇
  2019年   268篇
  2018年   317篇
  2017年   249篇
  2016年   226篇
  2015年   288篇
  2014年   464篇
  2013年   650篇
  2012年   975篇
  2011年   1048篇
  2010年   581篇
  2009年   547篇
  2008年   890篇
  2007年   1024篇
  2006年   998篇
  2005年   947篇
  2004年   894篇
  2003年   855篇
  2002年   832篇
  2001年   407篇
  2000年   359篇
  1999年   333篇
  1998年   218篇
  1997年   152篇
  1996年   144篇
  1995年   144篇
  1994年   132篇
  1993年   129篇
  1992年   234篇
  1991年   225篇
  1990年   219篇
  1989年   241篇
  1988年   192篇
  1987年   193篇
  1986年   176篇
  1985年   182篇
  1984年   154篇
  1983年   111篇
  1982年   78篇
  1981年   67篇
  1980年   71篇
  1979年   83篇
  1978年   74篇
  1977年   70篇
  1975年   71篇
  1974年   68篇
  1973年   69篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
Interferon-alpha (IFN-alpha) has proved effective in the treatment of hemangiomas, hemangioblastomas, and Kaposi's sarcoma. To investigate the ability of IFNs to inhibit angiosarcoma, we used two transformed murine endothelial cell lines that form angiosarcomas in vivo. SVR and MS1-VEGF cell lines express oncogenic H-ras or vascular endothelial growth factor (VEGF), respectively. IFN-alpha1,8, which is active against murine and human cells, inhibited SVR and MS1-VEGF proliferation in vitro by 40% at 10(3) U/mL (p = 0.028). In vivo, IFN-alpha1,8 inhibited SVR tumor volume by 71% (p = 0.047) and MS1-VEGF volume by 79% (p = 0.003). Tumor-induced angiogenesis was decreased in SVR tumors by 52% (p = 0.005) and in MS1-VEGF tumors by 58% (p = 0.001). Sera from IFN-alpha1,8-treated mice bearing either SVR or MS1-VEGF tumors demonstrated a 5-fold increase in IP-10/CXCL10 (p = 0.001), an IFN-induced antiangiogenic protein. Both recombinant IP-10 and IFN-alpha1,8 inhibited human umbilical vein endothelial cell (HUVEC) vessel formation in the fibrin gel assay, a three-dimensional culture model of angiogenesis, by 56% at 25 ng/mL and 50% at 1.2 ng/mL, respectively (p < 0.001). An IP-10 blocking antibody restored vessel formation to 80% of untreated controls (p = 0.001). Given the magnitude of the in vivo response, these data suggested that the antitumor effects of IFN-alpha1,8 were likely mediated through angiogenesis inhibition rather than solely by direct inhibition of tumor cell proliferation.  相似文献   
4.
5.
PURPOSE: Gas embolism is a rare but well documented entity during operative hysteroscopy, with an incidence of 10-50%. Catastrophic outcomes occur at a rate of three in 17,000 procedures. The purpose of this report is to present a non-fatal case of gas embolism probably caused by the gaseous products of combustion. CLINICAL FEATURES: A 50-yr-old woman with a history of menorrhagia was scheduled for hysteroscopy and endometrial ablation and polypectomy. Fifteen minutes into the procedure, with the patient in lithotomy position, 20 degree head down tilt, and breathing spontaneously, a sudden oxygen desaturation occurred from 97% to 87%. The patient's end-tidal carbon dioxide dropped from 46 mmHg to 27 mmHg. The patient's breathing pattern remained normal, respiratory rate remained 11-12 breaths x min(-1) but amplitude of the reservoir bag movement was increased. Cardiovascular variables remained stable. She responded rapidly to 100% oxygen and made an uneventful recovery. Having ruled out other possible causes, we concluded gas embolism was responsible for the fall in oxygen saturation and end-tidal CO(2). CONCLUSION: With all the precautions in place to minimize the likelihood of fluid overload and ambient air embolism occurring, we surmised that products of combustion were the cause of the gas embolism. During endometrial ablation, gaseous products of combustion, mainly carbon dioxide, accumulate. The gases may then contribute to the rise in uterine pressure that occurs as irrigation fluid enters the uterus and this rise in pressure in turn encourages passage of gas into the open venous sinuses.  相似文献   
6.
A crossover double-blind controlled trial was performed on 36 patients with rheumatoid arthritis to assess the necessity for serum salicylate monitoring in determining optimal dosage. There was no clinically or statistically significant increase in the clinical improvement of patients associated with serum monitoring but potentially toxic serum levels occurred without tinnitus when serum monitoring was not used.  相似文献   
7.
8.
The well-publicised dangers of contracting infection from blood-borne viruses make an awareness of comprehensive protective measures for self and others an imperative for nurses. Sarah Hart reviews the precautions nurses should take when dealing with contaminated blood and other body fluids, and lays emphasis on the need for all nurses, regardless of the particular area in which they work, to adopt and promote safe practices.  相似文献   
9.
Free flaps have been used for over 30 years. During this period, improved anatomical understanding has increased donor options and available pedicle lengths, permitting safer, single-stage reconstructions with simpler anastomoses. Refinements, such as perforator flaps in particular, have greatly improved donor morbidity, recipient site cosmesis, and the ability to replace 'like with like' while retaining options for innervation. This case highlights the evolution from one of Europe's first free tissue transfers, effectively a perforator flap, through the advent of free muscle flaps to the current generation of contourable perforator flaps. Free flap transfer has become increasingly sophisticated, safer, and more predictable, yet the potential quality of reconstructive outcome has changed little.  相似文献   
10.
BACKGROUND: Simple surgical excision is one of the most common treatment methods in the dermatologist's armamentarium. We describe a precise postsurgical dressing technique that can be used for wound care of those patients whose treatment involves removal of lesions via cutaneous surgery. OBJECTIVE: To devise a novel, precise, and effective dressing technique for postsurgical wound care. MATERIALS AND METHODS: We describe the technique using common in-office instruments. RESULTS AND CONCLUSION: Wound dressings for lesions located on curved areas such as the ears, nose, cheeks, and chin often exhibit less than adequate adherence and stability. The kerf-cut dressing technique optimizes pliability of dressing tape, and this maximizes efficient and stable application of postsurgical wound dressings to curved areas of the body.  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