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   419921篇
  免费   26946篇
  国内免费   8928篇
耳鼻咽喉   5037篇
儿科学   11481篇
妇产科学   7564篇
基础医学   35165篇
口腔科学   8892篇
临床医学   43369篇
内科学   55942篇
皮肤病学   5658篇
神经病学   33490篇
特种医学   9425篇
外国民族医学   41篇
外科学   43122篇
综合类   58518篇
现状与发展   14篇
一般理论   34篇
预防医学   43685篇
眼科学   6589篇
药学   36429篇
  437篇
中国医学   35194篇
肿瘤学   15709篇
  2024年   1260篇
  2023年   6700篇
  2022年   12027篇
  2021年   16686篇
  2020年   15594篇
  2019年   21732篇
  2018年   19495篇
  2017年   15779篇
  2016年   12814篇
  2015年   12250篇
  2014年   25948篇
  2013年   28163篇
  2012年   22905篇
  2011年   24925篇
  2010年   20536篇
  2009年   17885篇
  2008年   17298篇
  2007年   17323篇
  2006年   15003篇
  2005年   12840篇
  2004年   10689篇
  2003年   9371篇
  2002年   7289篇
  2001年   6526篇
  2000年   5456篇
  1999年   4735篇
  1998年   3851篇
  1997年   3754篇
  1996年   3105篇
  1995年   2904篇
  1994年   2781篇
  1993年   2240篇
  1992年   2213篇
  1991年   1929篇
  1990年   1704篇
  1989年   1504篇
  1988年   1419篇
  1985年   4513篇
  1984年   5650篇
  1983年   3977篇
  1982年   4485篇
  1981年   4221篇
  1980年   3734篇
  1979年   3557篇
  1978年   3148篇
  1977年   2353篇
  1976年   2717篇
  1975年   2142篇
  1974年   1880篇
  1973年   1755篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
面斜裂整形修复中泪道重建术的探讨   总被引:4,自引:0,他引:4  
为了解决面斜裂整形修复中泪道重建的难题,1989年3月~1995年1月,对4例患者治疗中设计了三种手术方法:泪小管鼻腔吻合术;静脉血管或口腔粘膜移植重建泪道术;改良的泪囊鼻腔吻合术。术后重建的泪道置入导管3~6个月。经术后6个月~1年的观察,面部畸形整复,溢泪消失,红汞试验及泪道检查均通畅,效果满意。认为,应根据泪道畸形程度的不同,选择合适的手术方法,以取得最佳疗效。  相似文献   
132.
胸腰椎稳定性重建方法的改进   总被引:2,自引:2,他引:0  
为了改进胸腰椎脱位的治疗方法,更好地重建脊柱稳定性,设计了一种新的脊柱固定器械,由滚花钉及连接板构成,并通过椎弓根进行的一种脊柱后路短节段固定方法,脊柱固定范围限制在两个椎体间。1989年~1995年,临床应用这种新器械矫正胸腰椎脱位12例,经1~4年随访,畸形矫正满意,固定牢固。结果表明:该器械具有手术方法简单、固定牢固和手术创伤小等优点。认为,该项技术适用于胸腰椎稳定性的重建。  相似文献   
133.
维持性血透患者的心理状态研究   总被引:28,自引:0,他引:28  
研究我国血透患者的心理状况并进行针对性的心理治疗。方法 采用症状自评量表(SCL90-R)、多维度健康状况心理控制源量表(MHLC)、艾森克个性问卷(EPQ)及终末期肾脏病(ESRD)患者专用的生活质量表对北京六个医院透析中心的92名维持性血透患者进行了心理状态的研究,并与美国及加拿大相同的研究进行了比较分析。结果 本组的血透存在着抑郁、焦虑、恐怖等心理障碍,出现心理障碍的比例显著高于美国同类患者(P<0.01),且焦虑的发生率高于美国同类患者(P<0.01)。这些障碍与MHLC中机遇项分(CED)显著相关(P<0.01)。EPQ中神经质项分高者倾向于发生抑郁、焦虑等心理障碍。本组的血透患者客观生活质量较加拿大同类患者低(P<0.01),但在总的生活满意度上没有显著性差异。生活质量与心理及躯体因素均呈显著相关,心理障碍与躯体症状也显著相关(P<0.01)。结论 本组的血透患者心理状态与美国加拿大同类患者相比既有相同之处,又有特殊之处。我们应该兼顾病人的躯体和精神两方面的健康,努力提高他们的生活质量。  相似文献   
134.
The post-lumbar puncture syndrome (PLPS) can best be explained by prolonged spinal fluid leakage owing to delayed closure of a dural defect. Its incidence after spinal anaesthesia is much lower than after diagnostic lumbar puncture (LP). This difference could be caused by a strand of arachnoid, which might enter the needle with the outflowing cerebrospinal fluid (CSF) during diagnostic LP and upon removal of the needle be threaded back through the dura to produce prolonged CSF leakage. To find a technique that further reduces the incidence of PLPS, this hypothesis was tested by evaluating the effect that reinserting the stylet before removing the needle had on the incidence of PLPS. By reinserting the stylet to the tip of the needle, the hypothesized strand would be pushed out, thereby reducing the frequency of PLPS. Sprotte’s “atraumatic needle” (21 gauge) was used for LP. A total of 600 patients participated in the prospective study. They were randomized into two groups and questioned about their complaints every day for up to 7 days after the LP. All LPs were performed by two experienced neurologists (T.B., M.S.). In 300 patients, the stylet was reinserted to the tip of the needle; in the other 300 it was not reinserted. Whereas 49 of the 300 patients without reinsertion developed PLPS, only 15 of the 300 patients with reinsertion did. This significant difference (16.3 vs 5.0%, P < 0.005, chi square test) supports our hypothesis. On the basis of our results, we recommend reinserting the stylet before removing the needle in order to reduce the incidence of PLPS. Received: 30 September 1997 Received in revised form: 9 March 1998 Accepted: 20 March 1998  相似文献   
135.
Drug related hospital admissions   总被引:13,自引:0,他引:13  
Summary As part of a high-intensity monitoring study of drug events as the cause of admission to departments of internal medicine, the effect of an educational intervention programme was studied. Two departments were included, one specialising in geriatrics and one that received patients by non-selected referral. The series consisted of 607 consecutive admissions studied before and 703 after the intervention. The drug events considered were adverse drug reactions and dose-related therapeutic failures, mainly due to non-compliance.A modest, statistically non-significant decrease in drug related hospital admissions (DRH) was seen, from 14% before to 13% after the intervention period. However, DRHs classified as definitely avoidable showed the significant decrease of 83%.There was no apparent relationship between the topics selected for the intervention programme and changes in the pattern of DRHs. No relationship between alterations in sales data and hospital admissions caused by a given drug could be demonstrated. A blinded external evaluation of case abstracts did not disclose any significant shift in the investigators' assessments.The intervention may have had an non-specific effect on avoidable DRHs.  相似文献   
136.
针药并用治疗男性不育297例疗效分析   总被引:2,自引:0,他引:2  
郑宗昌 《中医杂志》1995,36(6):349-350
本文采用针刺加鹿茸精注射液穴位注射及中药治疗男性不育297例,痊愈142例,占47.8%,显效81例,占27.3%,有效53例,占17.8%,无效21例,占7.1%,三者联合运用效果较满意。  相似文献   
137.
The purpose of this study was to assess the degree of consistency in student ratings of teacher effectiveness during the first year of medical school. Student ratings of teaching effectiveness represent a commonly used source of information that enters into the academic decision-making process. In medical school, student evaluations often represent a major source of information that is used in promotion and tenure decisions. It is essential that the precision of such ratings be ascertained so that decision-makers will know how much confidence to place in this source of information on teaching effectiveness. In this study, each member of a first-year medical school class was randomly assigned a two-digit identification number at the beginning of the spring semester, 1986. As the semester progressed students were asked to evaluate each full-time teacher in three major courses. Multiple instructors were utilized in each course (n = 10). Each teacher was evaluated immediately after lectures during the first (T1) and second (T2) halves of the course. Students evaluated the teacher a third time (T3) as part of the end-of-semester overall course evaluation. The teachers were evaluated on a short eight-item Likert-type scale that identified several key indicators of effective teaching. Students attached their anonymous identification numbers to individual ratings so that their responses could be matched in the analysis. The results indicate that medical students are only moderately consistent in the extent to which they evaluate teachers. This inconsistency varied by course and by instructors within courses.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
138.
小儿先天性髋关节脱位近年来应用术式的演变及其评估   总被引:5,自引:2,他引:3  
本文介绍本院近4年来小儿先天性髋脱位治疗应用术式的演变。由20多年来一直喜欢用骨盆截骨术演变为近1年来用得最多的是造盖术。近4年共手术463例,565髋。实践证明:比起骨盆截骨术,造盖术显得更简便,侵袭小,不需二次手术拔除内固定针。因在我国大龄髋脱位偏多,造盖术更适合我国国情。经过一些改进,可以克服造盖折断和吸收问题。  相似文献   
139.
The pharmacokinetics and haemodynamic effects of isosorbide dinitrate (ISDN) have been investigated following administration of single doses as a sublingual (SL) spray (2.5 mg), sublingual tablet (5 mg) and peroral tablet (10 mg) in a randomised, placebo-controlled double-blind cross-over trial in 16 healthy volunteers.After the sublingual spray Cmax was higher (39.0 ng·ml-1) and tmax was shorter (3.9 min) than after the sublingual (22.8 ng·ml-1 and 13.8 min) and peroral (16.9 ng·ml-1 and 25.6 min) tablets. The AUC of ISDN did not differ following any of the three formulations (1031; 879; 997 ng·ml-1·min, for the spray, SL tablet and PO-tablet, respectively). Mononitrate metabolites of ISDN (IS-2-MN and IS-5-MN) and total nitrates in plasma increased in proportion to the administered dose. This indicates that the fraction of the dose absorbed was the same for all the formulations but that the extent of first-pass metabolism increased in the order sublingual spray < sublingual tablet < peroral tablet. Thus, compared to the spray, the relative bioavailability of ISDN was 48% and 28% from the sublingual and peroral tablets, respectively.The haemodynamic effects were quantified using the a/b ratio of the finger pulse wave and the systolic blood pressure and heart rate under orthostatic conditions. For the a/b ratio of the finger pulse, the maximal effect was higher (emax=130%) and the time to emax (temax) shorter (16.6 min) after the spray than the sublingual tablet (84.4% and 25.5 min) or peroral tablet (90.2 and 31.3 min). The onset of effect was within 3, 5 and 7.5 min after the spray, sublingual and peroral tablets, respectively. A larger change in the orthostatically-induced decrease in systolic blood pressure and increase in heart rate was obtained following peroral than sublingual administration despite the similar plasma concentrations of ISDN. This probably reflects the larger amount of pharmacodynamically active mononitrate metabolites formed after oral dosing. The integrated effect following administration of 2.5 mg ISDN as spray was similar to that of a sublingual tablet of 5 mg.  相似文献   
140.
Twenty-four patients treated with 150 mg amitriptyline per day for an episode of major depression underwent a standardized heart rate analysis (HRA) before therapy and after 14 days. The battery of cardiovascular reflex tests included the determination of the coefficient of variation (CV) while resting and during deep respiration, a spectral analysis of heart rate, the heart rate response to standing, and the Valsalva manoeuvre. The results of the initial HRA did not differ from a group of 24 normal control subjects matched for age and sex. On day 14 of treatment the patients showed significantly reduced values of heart rate variability in all tests (P<0.0001), probably due to the anticholinergic side effects of amitriptyline. Heart rate increased form 78.1 to 93.6 bpm on average (P<0.0001). Abnormal CV at rest was registered in 96% of the patients; during deep respiration 29% showed abnormal CV results. An abnormal spectral analysis was found in 100% of the cases (low frequency peak: 42%, mid-frequency peak: 100%, high frequency peak: 79%). The heart rate response to standing was abnormal in 75% and the Valsalva test in 33% of the cases. Eighty-eight percent of the patients fulfilled the criteria of a cardiovascular autonomic neuropathy under the conditions of amitriptyline therapy. As yet, the consequences of these changes for the patients have not been sufficiently elucidated.  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