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   248508篇
  免费   21233篇
  国内免费   14757篇
耳鼻咽喉   2215篇
儿科学   3107篇
妇产科学   4972篇
基础医学   28941篇
口腔科学   4298篇
临床医学   31639篇
内科学   40632篇
皮肤病学   2873篇
神经病学   13760篇
特种医学   8790篇
外国民族医学   97篇
外科学   27184篇
综合类   35511篇
现状与发展   48篇
一般理论   49篇
预防医学   15748篇
眼科学   6839篇
药学   24894篇
  171篇
中国医学   11577篇
肿瘤学   21153篇
  2024年   756篇
  2023年   3631篇
  2022年   9075篇
  2021年   11875篇
  2020年   8739篇
  2019年   7829篇
  2018年   8262篇
  2017年   7235篇
  2016年   6890篇
  2015年   10416篇
  2014年   13079篇
  2013年   12267篇
  2012年   18099篇
  2011年   19771篇
  2010年   12056篇
  2009年   9678篇
  2008年   13116篇
  2007年   13168篇
  2006年   12604篇
  2005年   12698篇
  2004年   8773篇
  2003年   7812篇
  2002年   6749篇
  2001年   6107篇
  2000年   6193篇
  1999年   6498篇
  1998年   3702篇
  1997年   3719篇
  1996年   2836篇
  1995年   2617篇
  1994年   2257篇
  1993年   1512篇
  1992年   2325篇
  1991年   2019篇
  1990年   1675篇
  1989年   1469篇
  1988年   1286篇
  1987年   1185篇
  1986年   956篇
  1985年   751篇
  1984年   492篇
  1983年   381篇
  1982年   229篇
  1981年   201篇
  1980年   191篇
  1979年   245篇
  1978年   142篇
  1977年   113篇
  1976年   98篇
  1974年   116篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
We report a case of calcified chronic encapsulated intracerebral haematoma (ICH) in a 29-year-old female who presented with progressive left sided weakness and intermittent seizures since childhood. The preoperative magnetic resonance (MR) imaging of the head initially suggested that a partially thrombosed aneurysm or vascular malformation was present. However, no vascular stain was found on the digital subtraction angiography (DSA) of both the carotid and vertebral arteries. The excised mass was histologically diagnosed as a chronic ICH. We traced the patient's medical history and found that at the age of one she sustained a head injury after a fall. So far, to our knowledge, no case of epilepsy secondary to a calcified chronic encapsulated ICH occurring 28 years after head injury has been reported. Calcified chronic encapsulated ICH concomitant with new bone formation within is even rarer. The possible pathogenesis of this case is discussed.  相似文献   
52.
谈耳鼻喉科教学中多媒体技术的应用   总被引:3,自引:0,他引:3  
多媒体教学技术应用于耳鼻喉科教学,具有直观性好、动态感强、信息量大等优点,能使教学信息直接、形象、具体、生动地展现给学生,让学生体会到学习的乐趣,是耳鼻喉科现代化教学的理想模式.  相似文献   
53.
In 1998, an epithermal neutron test beam was designed and constructed at the Tsing Hua Open-Pool Reactor (THOR) for the purpose of preliminary dosimetric experiments in boron neutron capture therapy (BNCT). A new epithermal neutron beam was designed at this facility, and is currently under construction, with clinical trials targeted in late 2004. Depth dose-rate distributions for the THOR BNCT test beam have been measured by means of activation foil and dual ion chamber techniques. Neutron and structure-induced gamma spectra measured at the test beam exit were configured into a source function for the Monte Carlo-based treatment planning code NCTPlan. Dose-rate scaling factors (DRSFs) were determined to normalize computationally derived dose-rate distributions with experimental measurements in corresponding mathematical and physical phantoms, and to thus enable accurate treatment planning using the NCTPlan code. A similar approach will be implemented in characterizing the new THOR epithermal beam in preparation for clinical studies. This paper reports the in-phantom calculated and experimental dosimetry comparisons and derived DRSFs obtained with the THOR test beam.  相似文献   
54.
关木通引起慢性间质性肾炎7例报告   总被引:3,自引:0,他引:3  
目的 观察关木通所致慢性肾损伤的临床和病理改变特点。方法 本组 7例中 ,男 5例 ,女 2例。 3例服关木通汤药 ,4例服含关木通成药。分析服用时间、累积总量与肾损害首发症状及症状出现时间、肾功能和肾病理改变的关系。结果 汤药组 :服药时间平均 3 3 3个月 ,累积总量平均 82 9 3 g ,首发症状为乏力 3例 ,夜尿增多 2例 ,平均时间为 8 3个月 ,Cr平均 40 2 μmol/L。肾病理 :3例均为重度寡细胞性肾间质纤维化 ,肾小管广泛萎缩。成药组 :服药时间平均 7 5个月 ,累积总量平均 13 6g ,乏力 3例 ,夜尿增多 1例 ,恶心呕吐、头痛头晕 1例 ,平均18 8个月 ,Cr 3 62 8μmol/L。肾病理为重度寡细胞性间质纤维化和灶状纤维化各 2例 ,肾小管灶状萎缩 3例 ,广泛萎缩 1例。结论 汤药组关木通积累大 ,发病时间早 ,肾病理改变重。提示关木通所致肾损其临床表现、病理改变与服用关木通时间、剂量相关。  相似文献   
55.
Bismuth subnitrate (BSN), a bismuth compound medically used for antidiarrheics, was orally administered to see whether it can reduce CDDP nephrotoxicity or not. Thirteen patients aged 19 approximately 60 with ovarian cancer entered this BSN-CDDP trial. A total of thirty three courses of BSN-CDDP treatment was undergone. BSN was administered orally at a dose of 50 mg/kg for five days before CDDP therapy. CDDP was infused for two hours. No vigorous hydration or diuresis was performed. Only 2,000 ml of saline with 20 mEq per liter of KCl was given for post-hydration. The median dose of CDDP was 100 mg/m2. The renal toxicity of BSN-CDDP treatment was minimum. 82% of the courses at the sixth day after the treatment had creatinine clearance levels which were more than 80% of those before the treatment. But twenty-four hour NAG and beta 2-microglobulin excretion were significantly increased. Bone marrow suppression and gastrointestinal disturbance were commonly observed. The results of our study indicate that BSN pretreatment reduces the renal toxicity of CDDP to some extent.  相似文献   
56.
57.
58.
Serum thyroxine concentrations were measured sequentially in eight healthy male volunteers after the oral administration of one of two brand name, commercially available thyroxine tablets. In all cases, levels peaked at 2 hours and did not return to baseline values until 24 hours after dosing. From 2 through 10 hours, statistically significant elevations in serum thyroxine concentrations were observed. Such fluctuations may be important in evaluating laboratory results in patients receiving replacement doses of thyroxine.  相似文献   
59.
The promoting effect of the Chinese medicinal herb, Wikstroemia chamaedaphne and Tung oil extracts (WC and HHPA) on carcinoma of uterine cervix induced by HSV-2 or MCA in mice was studied. The results showed that WC and HHPA extracts were not carcinogenic themselves. After carcinogen HSV-2 and MCA treatment, WC and HHPA were added separately. The inducing rates by HSV-2 increased from 7.4% to 21.1% and 26.3%, those by MCA increased from 56.5% to 82.8% and 84.4%. There was a significant difference between the combined groups and groups with HSV-2 or MCA only. The experimental results suggest that these two kinds of extracts play a promoting effect on carcinogenesis. The relation between the carcinogenesis of uterine cervix or nasopharynx and WC or HHPA extracts is discussed.  相似文献   
60.
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