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   11823篇
  免费   686篇
  国内免费   234篇
耳鼻咽喉   141篇
儿科学   290篇
妇产科学   101篇
基础医学   911篇
口腔科学   105篇
临床医学   905篇
内科学   938篇
皮肤病学   56篇
神经病学   196篇
特种医学   325篇
外科学   3269篇
综合类   1805篇
预防医学   970篇
眼科学   19篇
药学   1424篇
  10篇
中国医学   814篇
肿瘤学   464篇
  2024年   26篇
  2023年   241篇
  2022年   542篇
  2021年   588篇
  2020年   463篇
  2019年   442篇
  2018年   420篇
  2017年   402篇
  2016年   410篇
  2015年   412篇
  2014年   866篇
  2013年   720篇
  2012年   793篇
  2011年   837篇
  2010年   619篇
  2009年   617篇
  2008年   585篇
  2007年   644篇
  2006年   476篇
  2005年   430篇
  2004年   325篇
  2003年   244篇
  2002年   202篇
  2001年   190篇
  2000年   171篇
  1999年   130篇
  1998年   105篇
  1997年   85篇
  1996年   72篇
  1995年   74篇
  1994年   51篇
  1993年   50篇
  1992年   46篇
  1991年   47篇
  1990年   38篇
  1989年   33篇
  1988年   39篇
  1987年   33篇
  1986年   24篇
  1985年   31篇
  1984年   32篇
  1983年   45篇
  1982年   29篇
  1981年   26篇
  1980年   22篇
  1979年   20篇
  1978年   7篇
  1977年   8篇
  1975年   8篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
目的:探讨一期全膝关节表面置换术治疗双膝骨关节病的可行性及疗效。方法:采用全膝关节表面置换术治疗双侧膝骨关节病患者16例,其中一期手术8例(Ⅰ组),分期手术8例(Ⅱ组)。结果:16例均得到随访1~3a,平均16个月。Ⅰ组术中出血量、输血量、手术时间、住院日,明显低于Ⅱ组(P〈0.05);术后膝关节HSS评分,两组间比较其差异无统计学意义(P〉0.05)。结论:应用一期全膝关节表面置换术治疗双膝骨关节病安全,且近期疗效满意。  相似文献   
102.
Previous studies demonstrated distinct cardiovascular patterns associated with threat and challenge appraisals for groups of participants. We extend these results by assessing whether appraisals continue to be associated with these cardiovascular response patterns within an individual as appraisals change. Participants completed four verbal mental arithmetic tasks for which they made appraisals before and after each task. Cardiac reactivity and total peripheral resistance (TPR) were calculated for the first and last minutes of each task, and the number of responses and percent correct were measured for each task. In line with our prediction, pretask appraisals were related to some task-related cardiac responses across the four tasks. In addition, task-related cardiovascular reactivity and behaviors both influenced appraisals following the task. Our findings suggest that an idiographic analysis of appraisals, cardiovascular physiology, and task-related behaviors provides a richer understanding of the appraisal process and reveals sex differences deserving further assessment.  相似文献   
103.
本组应用研究结果表明:恶性血液病患者血清LSA与TSA含量(175±61mg/L与1025±388mg/L,n=72)均显著高于良性血液病组(110±46mg/L与733±295mg/L,n=80)和对照组(93±19mg/L与639±178mg/L,n=205)(P<0.001)。测定血清LSA与TSA诊断恶性血液病的敏感度分别为87.5%与72.2%(P<0.05),特异度分别为72.5%与67.5%(P>0.1),准确度为81.6%与71.7%(P<0.05),诊断效率为63.4%与48.7%(P<0.01),证明LSA对恶性血液病诊断的价值优于TSA。该二法诊断恶性病的假阳性主要来自感染性疾病。血清LSA含量监测对患者疗效与病情监视、预后分析等具有显著意义。  相似文献   
104.
目的观察仿生双动全髋关节置换术治疗强直性脊柱炎累及髋关节病变的临床疗效,并探讨双动臼杯在脊柱僵硬患者中应用的优势。方法回顾性分析河南省洛阳正骨医院2017年2月至2019年3月行双动全髋关节置换术的21例(41髋)强直性脊柱炎患者的临床资料,其中男18例,女3例。临床随访根据X线检查、Harris评分系统及手术前后髋关节总活动度进行评价。结果21例(41髋)患者均得到随访,随访时间13~38个月,中位数为25个月,平均(25.47±6.59)个月。Harris评分由术前(40.80±10.35)分增加到术后末次随访的(87.41±10.18)分,髋关节总活动度由术前(51.87±15.71)°增加到术后的(198.53±18.83)°,差异均具有统计学意义(P<0.05)。X线检查显示所有髋关节假体位置良好,2例(3髋)出现异位骨化,所有患者均未出现关节脱位、假体松动、感染。结论双动全髋关节置换术治疗强直性脊柱炎累及髋关节病变可明显改善髋关节功能,减轻疼痛,双动臼杯高稳定性的特点,降低了 AS患者髋臼假体安放的手术技术要求,容错率较高,从而最小化脱位的风险。  相似文献   
105.
计算机辅助全膝置换中股骨力线定位精度的实验研究   总被引:3,自引:0,他引:3  
摘要利用光学定位追踪仪确定全膝置换中患者的股骨头中心从而确定其股骨力线,在力线的定位精度分析中,首次采用股骨的三维重建模型进行精度校验。实验结果表明通过追踪固定于股骨末端的刚性定位器即能确定精确的股骨力线,与传统的髓内定位相比,不仅可重复性好,而且大大地提高了术中股骨力线的位置精度,将其位置偏差减小到10以内。  相似文献   
106.
BackgroundRestricted kinematically-aligned total knee arthroplasty (KA-TKA) is a reasonable modification to avoid the alignment outlier that may cause implant failure. However, despite a noted high incidence of constitutional varus in Japanese individuals, there has been no investigation into how many knees require the restriction in restricted KA-TKA (RKA-TKA) among Japanese patients. Therefore, we conducted a study using preoperative long-leg radiograms.MethodsWe studied long-leg radiographs of 228 knees in 114 consecutive patients. The numbers of knees within the safety range and their corrective osteotomy angle in the restriction algorithms advocated by Almaawi et al. (2017) and MacDessi et al. (2020) were evaluated.ResultsAccording to the algorithms used by Almaawi et al. and MacDessi et al., out of 228 knees, 46 (20%) and 39 (17%) fell within the safety range, respectively. The mean correction angles of the hip-knee-ankle angle, lateral distal femoral angle and medial proximal tibial angle were 2.8 ± 3.4°, 0.4 ± 1.4° and 2.4 ± 2.8° in the algorithm used by Almaawi et al., while they were −4.9 ± 4.7°, 1.1 ± 2.5° and −6.0 ± 3.4° in the algorithm used by MacDessi et al. Most of the knees needed to be restricted in order to perform RKA-TKA, regardless of the algorithm used.ConclusionsBased on a preoperative analysis of long-leg radiograms in a Japanese population, most knees fall out of the safety range in RKA-TKA. Surgeons must consider whether to allow component outlier or to perform corrective osteotomy that likely requires soft tissue release.  相似文献   
107.
To determine the daily energy requirement of elite synchronized swimmers during moderate-intensity training, the average daily energy expenditure measured by the doubly labeled water method, was calculated for nine female Japanese national team synchronized swimmers [four senior; mean (SD) 22.5 (1.0) years old, 52.2 (3.6) kg, and five junior; 17.6 (1.1) years old, 52.8 (2.3) kg]. Their total energy expenditure (TEE) was 11.5 (2.8) MJ · day−1 [2738 (672) kcal · day−1]. When compared with estimated energy requirements derived from “Recommended Dietary Allowances for the Japanese”, 12.1 (0.6) MJ · day−1 [2897 (139) kcal · day−1], there was no difference between mean actual and estimated energy requirements. However, there were considerable differences observed on an individual basis. Their energy intake, estimated from 7- day self-reported dietary records, was 8.9 (1.7) MJ · day−1 [2128 (395) kcal · day−1], which was significantly lower than their TEE (P < 0.05). Resting energy expenditure (REE), as determined by indirect calorimetry, was 5.2 (0.3) MJ · day−1 [1247 (75) kcal · day−1]. Their physical activity level (TEE/REE) was 2.18 (0.43). These results demonstrate that the TEE values of elite female synchronized swimmers are not dissimilar to those reported for athletes participating in other sports, especially competitive swimmers during moderate-intensity training. Accepted: 26 May 2000  相似文献   
108.
Previous studies have not defined the contribution of the splanchnic circulation to the total intravascular volume change associated with selective alpha adrenergic receptor stimulation. Since the splanchnic circulation is responsible for the total volume changes associated with other types of selective autonomic receptor stimulation, the present study was undertaken to examine the influence of alpha adrenergic receptor stimulation on splanchnic intravascular volume, the hemodynamic mechanism responsible for the splanchnic volume change, and the contribution of the splanchnic volume change to the change in total volume. In 35 anesthetized dogs, blood from the vena cavae was drained into an extracorporeal reservoir and returned to the right atrium at a constant rate so that changes in total intravascular volume could be measured as reciprocal changes in reservoir volume. Phenylephrine infusion (100 g/min) for 20 min in 28 dogs was associated with a decrease in total volume of 64±17 (SEM) ml (P<0.0001). The response was abolished by either alpha adrenergic blockade or evisceration but was not attenuated by beta adrenergic blockade, sinoaortic baroreceptor denervation, ganglionic blockade, or splenectomy. In 5 animals with separate splanchnic perfusion and drainage, total and splanchnic volumes decreased 59±8 ml (P<0.0001) and 317±20 ml (P<0.0001), respectively, while transhepatic vascular resistance increased 17±4 cm H2O·min/l (P<0.0001). These responses were abolished after alpha adrenergic blockade. Thus, splanchnic volume decreases with alpha adrenergic receptor stimulation, despite an increase in hepatic resistance to splanchnic, venous outflow. The splanchnic volume decrement is entirely responsible for the total volume decrement.The study was supported by NHLBI Grant 1 R23-HL27185, Grant 11-203-812 from the American Heart Association of Greater Hartford, Inc., and the Duberg Cardiovascular Research Fund. Dr. Rutlen was the Duberg Scholar in Cardiovascular Disease when the study was performed.This work was presented in part at the 1982 Scientific Sessions of the American Heart Association (Circ. 66:II-311)  相似文献   
109.
Douglas  Carroll  Michael G.  Harris  Gwen  Cross 《Psychophysiology》1991,28(4):438-446
Cardiac output, heart rate, stroke volume, pre-ejection period, total peripheral resistance, systolic and diastolic blood pressure, and oxygen consumption were monitored or derived in young men with mildly elevated casual blood pressures and unambiguously normotensive control subjects before, during, and after exposure to a mental arithmetic stress. Measurements were also taken while subjects underwent graded dynamic exercise. This permitted cardiac output-oxygen consumption regression equations to be calculated and, as a consequence, cardiac output during mental stress to be represented as additional cardiac output. Systolic and diastolic blood pressure were higher during all phases of the study in the mildly elevated blood pressure group. An overall groups effect during the mental stress phase of the experiment was observed for cardiac output and pre-ejection period, and the effect for stroke volume was close to significance. Significant Groups X Periods interactions were found for cardiac output and additional cardiac output, and the heart rate effect was nearly significant. Post-hoc comparisons here indicated that, in the main, group differences in these cardiac variables were more evident during the mental arithmetic stress than during the pre- and post-task baseline periods. Total peripheral resistance did not differ reliably between groups and the cardiac effects were specific to the mental stress phase of the study.  相似文献   
110.
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