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   8012篇
  免费   786篇
  国内免费   4篇
耳鼻咽喉   130篇
儿科学   186篇
妇产科学   176篇
基础医学   1114篇
口腔科学   180篇
临床医学   1037篇
内科学   1714篇
皮肤病学   117篇
神经病学   630篇
特种医学   224篇
外科学   1041篇
综合类   195篇
一般理论   1篇
预防医学   862篇
眼科学   187篇
药学   425篇
中国医学   5篇
肿瘤学   578篇
  2022年   54篇
  2021年   138篇
  2020年   76篇
  2019年   117篇
  2018年   136篇
  2017年   121篇
  2016年   129篇
  2015年   150篇
  2014年   184篇
  2013年   257篇
  2012年   471篇
  2011年   394篇
  2010年   229篇
  2009年   211篇
  2008年   366篇
  2007年   411篇
  2006年   358篇
  2005年   359篇
  2004年   361篇
  2003年   326篇
  2002年   303篇
  2001年   239篇
  2000年   221篇
  1999年   218篇
  1998年   80篇
  1997年   79篇
  1996年   67篇
  1994年   55篇
  1993年   63篇
  1992年   156篇
  1991年   166篇
  1990年   167篇
  1989年   160篇
  1988年   154篇
  1987年   131篇
  1986年   146篇
  1985年   137篇
  1984年   117篇
  1983年   128篇
  1982年   62篇
  1980年   59篇
  1979年   85篇
  1978年   71篇
  1977年   53篇
  1976年   61篇
  1975年   55篇
  1974年   71篇
  1973年   54篇
  1971年   56篇
  1970年   51篇
排序方式: 共有8802条查询结果,搜索用时 15 毫秒
81.
82.
Ranitidine bismuth citrate (Pylorid, Tritec) is a novel drug which heals peptic ulcers and when co-prescribed with either clarithromycin or amoxycillin eradicatesHelicobacter pylori. In controlled clinical studies it was well-tolerated when given alone or when co-prescribed with either antibiotic. Data from 20 clinical studies are reported in this analysis of safety with almost 5000 patients having received ranitidine bismuth citrate (200, 400, or 800 mg twice daily). The incidence of adverse events reported with this new drug, either alone or with an antibiotic, was not different from or lower than in patients given placebo and was independent of the dose of ranitidine bismuth citrate tested. Most commonly reported events (>1% of patients) were upper respiratory tract infection, constipation, diarrhoea, nausea and vomiting, dizziness, and headache, the latter being the only event reported by >2% of patients who received ranitidine bismuth citrate alone. Adverse events considered by the clinical investigator to be adverse reactions occurred with a similar frequency amongst patients given ranitidine bismuth citrate (8%), ranitidine hydrochloride (6%), or placebo (6%). The incidence of adverse reactions was greater when co-prescribed with amoxycillin (11%) or clarithromycin (20%) although it was not different from that noted with the antibiotics alone. Serious adverse events were reported in similar proportions of patients given placebo, ranitidine bismuth citrate alone or with an antibiotic, and ranitidine hydrochloride (range: <1-2%). The safety profile of ranitidine bismuth citrate was thus comparable to that of ranitidine hydrochloride (Zantac), a drug with a well-established record of safety in clinical use.  相似文献   
83.
84.
85.
86.
A 27-year-old woman with severe psychosis and mania associated with systemic lupus erythematosus was successfully treated with electroconvulsive therapy. Cyclophosphamide was given as an adjuvant. The use of electroconvulsive therapy in patients with lupus and psychiatric disorders is discussed.  相似文献   
87.
R M Fujitani  J L Mills  L M Wang  S M Taylor 《Journal of vascular surgery》1992,16(3):459-67; discussion 467-8
To determine the influence of unilateral internal carotid arterial occlusion (ICO) on Doppler frequency spectral analysis (DFSA) of the patent contralateral carotid artery, a retrospective review of 154 patients between July 1987 and December 1991 with angiographically confirmed ICO was performed, correlating duplex and arteriographic findings in a blinded fashion. Biplane arteriograms and bilateral carotid artery duplex studies that used a 5.0 MHz Doppler probe with a 1.5 mm3 sample volume at a 60 degree angle of insonation were performed on all patients. Each carotid artery was categorized by the severity of stenosis as quantified by arteriography: 1% to 15% (n = 41); 16% to 49% (n = 48), 50% to 79% (n = 21), 80% to 99% (n = 34), and bilateral occlusion (n = 10). DFSA peak systolic frequencies were commonly exaggerated in the presence of contralateral ICO and use of standard criteria for DFSA interpretation overestimated bifurcation stenoses in 43 of 89 lesions (48.3%) when determining nonhemodynamically significant lesions (less than 50% diameter reduction) with a sensitivity of only 57.3% and specificity of 96.9%. Conversely, prediction of hemodynamically significant lesions (greater than 50% diameter reduction) with standard criteria had 96.9% sensitivity but only 57.3% specificity. Modification of these criteria to account for the velocity increase or "jet effect" in the ipsilateral carotid artery system increased the sensitivity and specificity to 97.8% in predicting nonhemodynamically and hemodynamically significant stenoses respectively. A Doppler frequency spectrum with a peak systolic frequency (PSF) greater than 4.0 kHz and end-diastolic frequency (EDF) less than 5 kHz with an "open window" distinguished lesions with less than 50% diameter reduction.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
88.
89.
Acne-Prone Skin. Acne-prone skin appears to be more susceptible to certain extrinsic factors that can either exacerbate existing disease or generate new lesions. Awareness of the factors that could worsen or interfere with therapy is important. In addition, identification of patients with minimal acne who are prone to outbreaks from extrinsic factors and provision of relevant advice could prove beneficial to significant numbers of patients. Sensitive Skin. From the perspective of our research, the definition of sensitive skin is still evolving. Certain individuals may view sensitive skin as fashionable; however, clinicians and the people who work in the personal-care industry know that when certain materials are applied to the skin, some individuals report symptoms (burning, stinging, itching, a tight feeling) and sometimes show traditional signs of irritation. The reasons for sensitive skin in these individuals may be obvious, but many times the complaints and signs of irritation occur in individuals who appear to be normal. Using our ongoing work we would like to suggest that the label "sensitive skin" apply to the following four categories: 1. Those individuals with obvious skin disease. 2. Those individuals with subclinical (mild) or atypical clinical signs of disease. 3. Those individuals who have experienced past insults to the skin. 4. Those individuals who do not fit into one of the above three categories and appear to be "normal". To define sensitive skin fully we may need to perform full profiles of the skin of these patients. In addition to history and examination, a battery of noninvasive tests may be helpful.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
90.
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