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   46603篇
  免费   3107篇
  国内免费   913篇
耳鼻咽喉   358篇
儿科学   1193篇
妇产科学   1207篇
基础医学   5251篇
口腔科学   826篇
临床医学   4019篇
内科学   10994篇
皮肤病学   715篇
神经病学   4286篇
特种医学   1726篇
外国民族医学   2篇
外科学   6420篇
综合类   2079篇
现状与发展   1篇
一般理论   1篇
预防医学   2323篇
眼科学   587篇
药学   3952篇
  8篇
中国医学   952篇
肿瘤学   3723篇
  2023年   394篇
  2022年   894篇
  2021年   1715篇
  2020年   1065篇
  2019年   1154篇
  2018年   1294篇
  2017年   1071篇
  2016年   1121篇
  2015年   1409篇
  2014年   1820篇
  2013年   2260篇
  2012年   2938篇
  2011年   2948篇
  2010年   1771篇
  2009年   1626篇
  2008年   2472篇
  2007年   2511篇
  2006年   2316篇
  2005年   2203篇
  2004年   1999篇
  2003年   1723篇
  2002年   1562篇
  2001年   1428篇
  2000年   1351篇
  1999年   1257篇
  1998年   460篇
  1997年   341篇
  1996年   360篇
  1995年   284篇
  1994年   259篇
  1993年   220篇
  1992年   679篇
  1991年   579篇
  1990年   543篇
  1989年   550篇
  1988年   463篇
  1987年   425篇
  1986年   408篇
  1985年   319篇
  1984年   263篇
  1983年   215篇
  1982年   118篇
  1979年   211篇
  1978年   130篇
  1977年   111篇
  1974年   122篇
  1973年   126篇
  1972年   123篇
  1971年   110篇
  1969年   102篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Abstract

This study is a single-center, retrospective analysis of postmenopausal women presenting with dyspareunia and vulvar pain, aiming to evaluate relative effectiveness of vestibular CO2 laser therapy as a treatment. Three monthly sessions of laser were performed to each patient and thereafter a three-months follow-up was stablished. A total number of 72 patients undergoing vestibular laser treatment were recruited from patient files in the period between 2016 and 2018. Among these, 39 women also received a concomitant treatment with ospemifene (60?mg/day) during the study period. There was a statistically significant reduction of all the symptoms in both groups up to the three month follow-up. Regarding dryness and dyspareunia, the relief tent to be more prominent in the ospemifene?+?laser group at all follow-ups and remained statistically significant at three-month follow-up. Specifically, vestibular dryness was significantly lower in the ospemifene?+?laser group compared with the laser treatment group (?87% vs???34%, respectively), and the vestibular health score started declining faster in the ospemifene?+?laser group. Although, additional research is needed to understand the mechanism of action, our data shows that a combination regimen of laser and ospemifene may improve clinical effectiveness for long-term treatment of symptoms associated with the under-recognized genitourinary syndrome of menopause.  相似文献   
22.
目的 初步探讨应用艾尔巴韦/格拉瑞韦治疗慢性丙型肝炎(CHC)患者的疗效。方法 2017年3月~2018年3月仙桃市第一人民医院感染病科收治的CHC患者82例,被随机分为对照组41例和观察组41例,分别给予聚乙二醇干扰素-α联合利巴韦林治疗和艾尔巴韦/格拉瑞韦治疗,两组均连续治疗24周。采用RT- PCR法检测血清 HCV RNA,采用全基因序列测定法行病毒基因分型。比较两组早期病毒学应答(EVR)、治疗结束时病毒学应答(ETVR)和持续病毒学应答(SVR)。结果 在治疗结束时,观察组血清丙氨酸氨基转移酶(ALT)水平为(47.9±19.7)U/L,显著低于对照组【(63.5±21.2)U/L,P<0.05】,天冬氨酸氨基转移酶(AST)水平为(55.5±22.3)U/L,显著低于对照组【(81.3±25.8)U/L,P<0.05】;观察组EVR、ETVR和SVR分别为48.8%、63.4%和70.7%,与对照组的41.5%、53.7%和65.8%比,无统计学差异(P>0.05);18例观察组非HCV Ⅰ型感染者EVR、ETVR和SVR分别为88.9%、94.4%和88.9%,显著高于同组23例HCV Ⅰ型感染者(分别为52.2%、60.9%和52.2%, P<0.05),而与对照组15例非HCV Ⅰ型感染者比,无统计学差异(分别为86.7%、93.3%和73.3%, P>0.05);观察组SVR12为87.8%(36/41),显著高于对照组的73.2%(30/41,P<0.05)。结论 应用直接抗病毒(DAA)药物艾尔巴韦/格拉瑞韦治疗CHC患者近期疗效达到,但远期疗效似优于标准治疗方案, 值得临床进一步验证。  相似文献   
23.
24.
The purpose of the work was to set‐up a simple method to evaluate the contribution of Mn2+ ions in the intra‐ and extracellular tumor compartments in a MEMRI experiment. This task has been tackled by “silencing” the relaxation enhancement arising from Mn2+ ions in the extracellular space. In vitro relaxometric measurements allowed assessment of the sequestering activity of DO2A (1,4,7,10‐tetraazacyclododecane‐1,7‐diacetic acid) towards Mn2+ ions, as the addition of Ca‐DO2A to a solution of MnCl2 causes a drop of relaxivity upon the formation of the highly stable and low‐relaxivity Mn‐DO2A. It has been proved that the sequestering ability of DO2A towards Mn2+ ions is also fully effective in the presence of serum albumin. Moreover, it has been shown that Mn‐DO2A does not enter cell membranes, nor does the presence of Ca‐DO2A in the extracellular space prompt migration of Mn ions from the intracellular compartment. On this basis the in vivo, instantaneous, drop in SE% (percent signal enhancement) in T1‐weighted images is taken as evidence of the sequestration of extracellular Mn2+ ions upon addition of Ca‐DO2A. By applying the method to B16F10 tumor bearing mice, T1 decrease is readily detected in the tumor region, whereas a negligible change in SE% is observed in kidneys, liver and muscle. The relaxometric MRI results have been validated by ICP‐MS measurements. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
25.
Introduction: Recently, a new minimally invasive single bundle technique for anatomic ACL reconstruction has been described, called the ‘All-Inside graft-link technique’. One of the advantages of this procedure is the reduced morbidity at the donor site as the graft choice is the quadrupled semitendinosus, thus sparing the gracilis tendon. The aim of this study was to evaluate isokinetic flexion strength recovery in patients who underwent a gracilis sparing technique compared to those with a full-tibial tunnel technique using a doubled gracilis and semitendinosus tendons (DGST) graft.

Methods: Patients were divided into two groups: Group A (22 patients) who underwent ACL reconstruction performed with an All-Inside graft-link technique; Group B (22 patients) who underwent ACL reconstruction with an Out-In technique and DGST graft. At a mean follow-up of 13 months, quadriceps and hamstring isokinetic peak torque deficits were recorded.

Results: In group A, the mean side to side peak torque flexion difference between the operated and non-operated limbs was ?3% and the mean torque at 30° was ?7.5% at high angular velocity (180°/sec); the mean peak flexion torque was 7.2% and the mean torque at 30° was 3.1% at low angular velocity (60°/sec).

In group B, the mean side to side peak flexion torque was ?3.5% and the mean torque at 30° was ?7.6% at high angular velocity (180°/sec); the mean peak flexion torque was ?7.2% and the mean torque at 30° was ?11% at low angular velocity (60°/sec).

A statistically significant difference was found between the two groups at lower angular velocity both for the mean peak flexion torque and the mean torque at 30° (= 0.009), with better results in the study group.

Discussion/conclusion: Gracilis sparing technique is a minimally invasive technique for ACL reconstruction and yielded a significantly better flexion strength recovery at lower angular velocity compared to a full tibial tunnel technique with DGST for ACL reconstruction.  相似文献   

26.
27.
28.
Over the years, the number of total hip replacements has been steadily increasing. Despite the improvement in surgical results, the number of claims for malpractice is higher. The primary endpoint of this work is to provide an analysis of litigation after hip replacement, to outline what are the instigating causes and costs. The secondary endpoint is to propose a possible preventive strategy for an improved care and a reduction in legal proceedings. The data of this study were collected from medical and legal files and from professional liability insurance of our institution from January 2005 to December 2016. Out of a total of 4770 THA, 40 claims were received. Peripheral nerve injuries represent the first cause of litigation (37%), followed by infectious complications, leg length discrepancy, metallosis, dislocations of the implant and a case of deep vein thrombosis. From the analysis of the past trial judgment, complications such as nerve lesions and infections are almost always recognized, as a medical error, with a high percentage of claims settled. This study shows the necessity of preventive strategies to reduce the higher number of claims for malpractice in total hip arthroplasty. Some complications such as nerve injuries and infection are frequently considered directly dependent on physician’s errors. Litigations can be reduced providing evidence of a diligent execution of the surgical procedure and of a proper postoperative management: the correct compilation of a specific informed consent and adequate doctor–patient communication.  相似文献   
29.
目的 观察SWIM技术治疗后循环大血管闭塞所致急性缺血性卒中的有效性及安全性。 方法 回顾性分析2017年2月-2018年11月于大连市中心医院采用SWIM技术治疗的后循环大血管闭 塞所致急性缺血性卒中患者的临床资料,评价该技术的疗效和安全性,并分析影响患者预后的因素。 观察指标为术后即刻成功再通(mTICI≥2b)、90 d良好预后(mRS评分≤2分),以及术后24 h任何颅内 出血、90 d全因死亡。 结果 共纳入35例患者,平均年龄66.1±12.1岁,男性26例(74.3%),基线NIHSS评分22(15~34)分。 术后即刻成功再通率为94.3%(33/35),90 d良好预后率为45.7%(16/35),24 h颅内出血率为17.1% (6/35),90 d全因死亡率为37.1%(13/35)。单因素分析显示,基线NIHSS评分较低(P =0.001)、基 线后循环ASPECTS评分较高(P =0.016)、发病至到院时间较短(P =0.039)、发病至再通时间较短 (P =0.047)、血管成功再通率较高(P =0.036)以及饮酒比例较低(P =0.042)与良好预后相关。 结论 使用SWIM技术治疗后循环急性缺血性卒中相对安全、有效。  相似文献   
30.
This study evaluated the effect of new motions of the motor TriAuto ZX2 on the cyclic fatigue of endodontic instruments. Vortex Blue 35.06 instruments were divided into four groups (n = 10) and tested for fatigue in a curved artificial canal (90° and 2 mm radius) using the following motions: continuous rotation (CR), Optimum Torque Reverse (OTR) set at 180° and the Optimum Glide Path (OGP), which was tested at 90° and 240°. The time to fracture (TTF) and the lengths of the fractured fragments were recorded. The mean TTF was significantly different among the groups (anova , P < 0.05): OGP 90° (213.39 ± 27.45), OTR 180° (121.24 ± 17.03), OGP 240° (45.24 ± 5.61) and CR (8.43 ± 1.27). Weibull analysis confirmed the shortest life expectancy for CR and the longest survival for OGP at 90°. The resistance to fatigue was affected by motions and pre‐set angles. The proprietary movements that are currently available for endodontic instruments were classified according to their kinematics.  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