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   56524篇
  免费   4956篇
  国内免费   722篇
耳鼻咽喉   203篇
儿科学   435篇
妇产科学   533篇
基础医学   4879篇
口腔科学   1295篇
临床医学   8550篇
内科学   12913篇
皮肤病学   683篇
神经病学   2513篇
特种医学   720篇
外国民族医学   11篇
外科学   4062篇
综合类   6704篇
现状与发展   5篇
一般理论   17篇
预防医学   10416篇
眼科学   276篇
药学   4700篇
  93篇
中国医学   1055篇
肿瘤学   2139篇
  2024年   142篇
  2023年   981篇
  2022年   1704篇
  2021年   2198篇
  2020年   2388篇
  2019年   2118篇
  2018年   2296篇
  2017年   2419篇
  2016年   2627篇
  2015年   2363篇
  2014年   4200篇
  2013年   6015篇
  2012年   3608篇
  2011年   3747篇
  2010年   3036篇
  2009年   2801篇
  2008年   2661篇
  2007年   2531篇
  2006年   2194篇
  2005年   1725篇
  2004年   1493篇
  2003年   1367篇
  2002年   1107篇
  2001年   956篇
  2000年   758篇
  1999年   597篇
  1998年   556篇
  1997年   517篇
  1996年   389篇
  1995年   384篇
  1994年   367篇
  1993年   319篇
  1992年   275篇
  1991年   230篇
  1990年   209篇
  1989年   179篇
  1988年   146篇
  1987年   113篇
  1986年   68篇
  1985年   90篇
  1984年   73篇
  1983年   35篇
  1982年   58篇
  1981年   31篇
  1980年   30篇
  1979年   15篇
  1978年   18篇
  1977年   19篇
  1976年   15篇
  1974年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
方芳 《中华医护杂志》2007,4(11):1010-1011
目的探讨老年骨髓炎患者围术期护理的体会及经验。方法对32例老年骨髓炎患者围术期护理经验进行分析和总结。结果全组32例患者通过手术治疗及合理护理措施均得到治愈,无褥疮、肺部及泌尿系感染等并发症发生。结论老年骨髓炎患者体质差,合并症多,护理需认真、细致,并且根据术前、术中、术后按不同病情制订个案护理计划,预防并发症,能有效地提高手术成功率。  相似文献   
82.
目的探讨肥胖患者下腹部手术采用Joel—Cohen切口对预防非感染性切口裂开的临床效果。方法选择切口部位皮下脂肪层厚达4—5cm的妇产科手术患者90例,随机分为观察组44例,采用Joel—Cohen切口;对照组46例,采用下腹正中直切口。观察切口愈合和脂肪液化情况。结果观察组切口甲级愈合率显著高于对照组(P〈0.01);脂肪液化切口裂开率显著低于对照组(P〈0.05)。结论脂肪组织厚达4—5cm以上下腹部手术切口,采用Joel—Cohen切口可以减少脂肪液化,切口愈合显著优于下腹直切口,值得临床推广应用。  相似文献   
83.

Objectives

For individuals not on antiretroviral therapy, the risk of heterosexual transmission of HIV appears negligible when blood plasma (BP) viral loads are <1500 HIV‐1 RNA copies/mL. It is not clear whether this observation can be extrapolated to individuals on highly active antiretroviral therapy (HAART). Because of differential tissue penetration, antiretroviral drug concentrations may be sufficient to maintain an undetectable viral load in the BP yet not achieve adequate levels to suppress HIV in the genital tract. Therefore, we wanted to correlate HIV viral loads and drug concentrations in semen plasma (SP) and BP.

Methods

Thirty‐three men were included. All were on combination antiretroviral therapy with an undetectable BP viral load for at least 1 year. Blood and semen samples were collected within 2 h of each other and tested for HIV RNA by the NucliSens QT (bioMerieux, St Laurent, QC, Canada) method; drug concentrations were determined by liquid chromatography tandem mass spectrometry.

Results

Two of the 33 patients (6.1%) with BP viral loads below detection had time‐matched HIV viral loads in SP ≥700 copies/mL. Both patients were on efavirenz, the SP concentrations of which were ≤10% of the levels in BP and well below the minimal therapeutic drug monitoring target concentration required to suppress HIV.

Conclusions

Because, at least in part, of poor drug penetration into the genital tract, an undetectable HIV viral load in the BP does not guarantee an undetectable viral load in semen. In view of this, caution should be taken in concluding that patients on HAART with suppressed viraemia are sexually non‐infectious.  相似文献   
84.
Serum levels of Epinephrine (E), norepinephrine (NE), heart rate (HR), skin conductance reaction (SCR) and skin conductance level (SCL) were measured in schizophrenic, endogenous depressed and anxiety patients as well as in normal controls. Conditions were rest, noise and a mental arithmetic (MA) task. Schizophrenic and depressed patients had an attenuated HR response to MA. Moreover, Schizophrenic patients also had higher NE base level and the highest NE secretion during noise. Anxiety and depressed patients showed significantly lower phasic electrodermal activity (SCR) throughout the whole trial, exclusively anxiety patients had significantly higher tonic electrodermal activity (SCL). These findings indicate that autonomous reactions discriminate between patient groups and controls as well as between each other.  相似文献   
85.
Forty elderly patients with basicervical and pertrochanteric fractures were managed with uniplanar AO external fixator under regional anaesthetic block of the femoral nerve and lateral cutaneous nerve of the thigh from April 2003 to March 2006. The mean age of the patients was 67.9 ± 5.5 years. External fixator application was performed under radiological control after closed reduction had been obtained. Comorbid factors, duration of surgery, duration of hospitalisation, complications, walking ability, time to union and mortality rate were recorded. Patients were followed up for a mean period of 12 ± 4.5 months. Superficial pin tract infection occurred in 13 patients, healing in varus >10° and with shortening >2 cm occurred in six patients, and one patient suffered a spontaneous ipsilateral femoral neck fracture after removal of the fixator. The mean time for union was 10.4 ± 1.2 weeks. Rapid union rate and minor complications obtained in the present study are comparable to those obtained with standard internal fixation techniques. Minimal intraoperative blood loss, short operative time and early patient mobilisation are advantages signifying uniplanar external fixator application under regional anaesthetic block to be a viable option in treatment of basicervical and pertrochanteric fractures in high-risk elderly patients.  相似文献   
86.
目的探讨急性冠脉综合征(ACS)患者血浆瘦素(LP)及C-反应蛋白(CRP)水平的变化及其临床意义。方法测定急性心肌梗死组(AMI组)、不稳定型心绞痛组(UA组)、对照组(健康体检者)血浆LP及CRP浓度,分析LP、CRP与病情严重程度的关系以及LP与CRP的相关性。结果AMI组、UA组患者血浆LP、CRP浓度较对照组显著升高(P<0.01),2组患者血浆LP与CRP浓度之间均呈显著正相关;AMI组血浆LP、CRP浓度比UA组明显升高(P<0.05)。结论血浆LP及CRP浓度与ACS病情严重性呈正相关,且LP与CRP浓度呈正相关。说明LP与CRP共同参与组织炎症反应,是ACS重要的危险因素及预测因子。  相似文献   
87.
瑞芬太尼对老年患者麻醉诱导时血流动力学的影响   总被引:1,自引:0,他引:1  
周红梅  周清河  肖旺频 《医药导报》2007,26(9):1002-1003
[摘要]目的观察瑞芬太尼全麻诱导对老年患者血流动力学的影响。方法60例ASAⅠ~Ⅱ级老年患者随机分成3组,F组、R1组和R2组,每组20例。F组静脉诱导用药:咪达唑仑0.05 mg·kg-1,芬太尼3 μg·kg-1,丙泊酚1 mg·kg-1,待入睡后注入维库溴铵0.1 mg·kg-1气管插管;R1组用瑞芬太尼1 μg·kg-1代替芬太尼;R2组用瑞芬太尼1.5 μg·kg-1代替芬太尼。观察诱导时血压、心率的变化,同时记录使用阿托品和麻黄碱情况。结果R2组最低血压(MAP1 )、最高血压(MAP2)明显低于其他两组(P<0.05=; R2组 最低心率(HR1)、最高心率(HR2)明显低于F组(P<0.05=。结论瑞芬太尼可以用于老年患者的全麻诱导,但在诱导时要密切注意血流动力学变化。  相似文献   
88.
Screening of potential MRSA-positive patients at hospital admission is recommended in German and international guidelines. This policy has been shown to be effective in reducing the frequency of nosocomial MRSA transmissions in the event of an outbreak, but the influence of screening on reducing hospital-acquired MRSA infections in a hospital setting where MRSA is endemic is not yet well-documented. This study describes the effect of hospital-wide screening of defined risk groups in a 700-bed acute care hospital during a period of 19 months. In a cohort study with a 19-month control period, the frequencies of hospital-acquired MRSA infections were compared with and without screening. In the control period, there were 119 MRSA-positive patients, of whom 48 had a hospital-acquired MRSA infection. On the basis of this frequency, a predicted total of 73.2 hospital-acquired MRSA infections was calculated for the screening period, but only 52% of the expected number (38 hospital-acquired MRSA infections) were observed, i.e., 48% of the predicted number of hospital-acquired MRSA infections were prevented by the screening programme. The screening programme was performed with minimal effort and can therefore be recommended as an effective measure to help prevent hospital-acquired MRSA infections.  相似文献   
89.
Pregnant and parenting adolescents living in inner cities are at risk for acquiring HIV through unprotected sexual activity. In addition to individual risk behaviors, a lack of socioeconomic and other environmental resources create risk environments that make certain communities vulnerable to both adolescent pregnancy and HIV/AIDS. Research indicates that adolescent parents, many who have histories of childhood trauma, may use their experience of young parenthood and the concomitant feelings of parental protectiveness as a source of renewed hope for their future. The purpose of this report is to explore the relationship between history of childhood abuse and high risk behaviors in adolescent Latino mothers and fathers enrolled in a randomized clinical trial of a culturally rooted, couple-focused HIV prevention program. In addition, this report describes the HIV prevention program that was designed specifically for young Latino parents wherein maternal and paternal protectiveness are viewed as intrinsic and developing critical factors that promote resiliency and motivate behavioral change.  相似文献   
90.
Objective: To examine the effectiveness of needle and syringe programmes (NSPs) in preventing HIV transmission among injecting drug users (IDUs).Methods: An ecological study design was used to determine change in HIV prevalence among injecting drug users between cities with and without NSPs. Several data sources, such as electronic journal databases, surveillance reports, websites, and index review of relevant journals, were used to identify studies of HIV seroprevalence among IDUs, and presence of NSPs. The rate of change in HIV prevalence was estimated by regression analysis.Results: There were 778 years of data from 99 cities globally included in the analysis. HIV prevalence decreased by 18.6% per annum in cities that introduce NSPs, and increased by 8.1% in cities that had never introduced NSPs (mean difference −24.7% [95% CI: −43.8, 0.5%], P=0.06). The mean difference was –33% when comparison was weighted to one over the variance of the regression estimator (29% decrease in cities with NSPs and 5% increase in cities without NSPs, P<0.001). When analysis was restricted to cities with first HIV seroprevalence less than 10%, the average annual change in seroprevalence was 18% lower in cities with NSPs (P=0.03).Conclusions: Despite the inherent limitations within an ecological study design, the study provides additional evidence that NSPs reduce transmission of HIV infection. The rapid spread of HIV among IDU populations and increasing rates of injecting in many countries calls for scaling up of NSPs as well as other harm reduction strategies.  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