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   93941篇
  免费   7064篇
  国内免费   2400篇
耳鼻咽喉   662篇
儿科学   2197篇
妇产科学   1352篇
基础医学   9112篇
口腔科学   1980篇
临床医学   9459篇
内科学   12645篇
皮肤病学   766篇
神经病学   9856篇
特种医学   2814篇
外国民族医学   3篇
外科学   7303篇
综合类   14377篇
现状与发展   7篇
预防医学   13695篇
眼科学   1001篇
药学   9407篇
  128篇
中国医学   3369篇
肿瘤学   3272篇
  2024年   120篇
  2023年   1729篇
  2022年   2573篇
  2021年   4299篇
  2020年   4178篇
  2019年   3479篇
  2018年   3442篇
  2017年   3012篇
  2016年   3170篇
  2015年   3088篇
  2014年   6390篇
  2013年   6670篇
  2012年   5800篇
  2011年   6316篇
  2010年   4984篇
  2009年   4792篇
  2008年   4781篇
  2007年   4632篇
  2006年   3918篇
  2005年   3406篇
  2004年   2781篇
  2003年   2424篇
  2002年   1845篇
  2001年   1643篇
  2000年   1316篇
  1999年   1121篇
  1998年   975篇
  1997年   937篇
  1996年   782篇
  1995年   845篇
  1994年   821篇
  1993年   693篇
  1992年   671篇
  1991年   640篇
  1990年   523篇
  1989年   465篇
  1988年   454篇
  1987年   438篇
  1986年   393篇
  1985年   526篇
  1984年   453篇
  1983年   285篇
  1982年   304篇
  1981年   276篇
  1980年   255篇
  1979年   162篇
  1978年   157篇
  1977年   134篇
  1976年   102篇
  1974年   50篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.  相似文献   
2.
3.
4.
5.
A delayed haemolytic transfusion reaction (DHTR) encompasses a positive direct antiglobulin test (DAT) developed anytime between 24 hours to 28 days after cessation of transfusion, a positive eluate or a newly identified alloantibody in the plasma or serum along with features of haemolysis in the patient. Routinely, it is expected that with the transfusion of one unit of packed red cells in a patient of average height and weight, the haemoglobin level and hematocrit increase by 1 g/dL and 3% respectively. However, in a patient with DHTR, an inadequate rise of post-transfusion haemoglobin (< 1 g/dL) or rapid fall in haemoglobin back to pre-transfusion levels is observed. Kidd antibodies are particularly known to cause DHTR, maybe alone or in unison with other antibodies. Detection of these alloantibodies is consequential in providing good transfusion support to these patients. These events may be difficult to detect as they may present as varied clinical features or immunological nuisances. In this case series, we have presented three cases of DHTR with special emphasis on their clinical presentations, immunohaematological evaluations, laboratory parameters and the role of proper transfusion support in these patients to avoid further complications.  相似文献   
6.
7.
BackgroundOverordering of blood has been a challenge faced by the blood bank staff. The present study addresses the role of maximum surgical blood ordering schedule (MSBOS) in optimizing the blood inventory management.MethodsThe blood requests for elective surgical procedures from various surgical departments were reviewed to constitute MSBOS. Transfusion profile was assessed using crossmatch to transfused units (C/T) ratio, transfusion probability (TP), and transfusion index (TI). A cutoff of 0.3 and 5% value of TI and TP, respectively, was considered to decide on the type of crossmatch. The efficacy of MSBOS implementation has been determined prospectively by unpaired t test using SPSS software, version 20 (IBM, USA).ResultsA total of 2674 patients were studied. Overall red cell usage rate was 15%. The comprehensive C/T ratio was 4.57. The C/T ratios for the various departments ranged from 1 to 8.5 (adjusted C/T ratio). Highest C/T ratio was observed for surgical procedures performed in the specialties of otorhinolaryngology and urology. A C/T ratio greater than 5 was noted in 30.4% of different types of surgical procedures. Of the 176 different types of elective surgical procedures studied, type and screen protocol was applicable for 75.5% (133) of the procedures. After implementation of MSBOS, the number of crossmatches reduced by 2152 and total working time saved in our laboratory is close to 75,320 man hours.ConclusionMSBOS helps in identifying the common surgical procedures with low TP and is one of the efficient tools in preventing the overordering of the blood.  相似文献   
8.
目的 探讨医院信息系统中增加住院陪护管理功能的应用效果。方法 基于互联网医院、智慧医院等信息系统,开发信息化住院陪护管理功能,包括流行病学史调查、免费核酸申请、电子陪护证办理、体温监测登记及上报和统计查询。该功能与医院智慧护理链接后全院应用。比较功能应用前和应用后的遵医嘱一患一陪达标率、有效陪护证达标率、体温监测并登记日上报达标率和陪护证使用追溯率,评价护士和管理者疫情防控管理的人均耗时以及对该管理功能的满意度。结果 应用信息化陪护管理功能后,一患一陪达标率、有效陪护证达标率、体温监测并登记日上报达标率和陪护证使用追溯率显著高于应用前(均P<0.05);护士陪护管理人均耗时从(554.13±30.77)s降至(311.67±21.54)s(P<0.05);护士和管理者对该信息化陪护管理功能的满意度显著提高(均P<0.05)。结论 信息化住院陪护管理功能的应用有效提升了疫情期间陪护的管理质量和管理效率,提高了一线护士和管理者的满意度。  相似文献   
9.
《Vaccine》2022,40(30):4038-4045
PurposeAs protection from COVID-19 following two doses of the BNT162b2 vaccine showed a time dependent waning, a third (booster) dose was administrated. This study aims to compare the antibody response following the third dose versus the second and to evaluate post-booster seroconversion.MethodsA prospective observational study conducted in Maccabi Healthcare Services. Serial SARS-CoV-2 Spike IgG tests, 1,2,3 and 6 months following the second vaccine dose and one month following the third were obtained. Neutralizing antibody levels were measured in a subset of participants. Per individual SARS-CoV-2 Spike IgG titer ratios were calculated one month after the booster administration compared to titers one month following the second dose and prior to booster.ResultsAmong 110 participants, 56 (51%) were women. Mean age was 61.7 ± 1.9 years and 66 (60%) were immunocompromised. One month after third dose, IgG titers were induced 7.83 (95 %CI 5.25–11.67) folds and 2.40 (95 %CI 1.90–3.03) folds compared to one month after the second, in the immunocompromised and immunocompetent groups, respectively. Of the 17 immunocompromised participants who were seronegative after the second dose, 4 (24%) became seropositive following the third. Comparing the titers prior to the third dose, an increase of 50.7 (95 %CI 32.5–79.1) fold in the immunocompromised group and 25.7 (95 %CI 19.1–34.7) fold in and immunocompetent group, was observed.ConclusionA third BNT162b2 vaccine elicited robust humoral response, superior to the response observed following the second, among immunocompetent and immunocompromised individuals.  相似文献   
10.
In this paper, effective Eulerian algorithms are introduced for the computation of the forward finite time Lyapunov exponent (FTLE) of smooth flow fields. The advantages of the proposed algorithms mainly manifest in two aspects. First, previous Eulerian approaches for computing the FTLE field are improved so that the Jacobian of the flow map can be obtained by directly solving a corresponding system of partial differential equations, rather than by implementing certain finite difference upon the flow map, which can significantly improve the accuracy of the numerical solution especially near the FTLE ridges. Second, in the proposed algorithms, all computations are done on the fly, that is, all required partial differential equations are solved forward in time, which is practically more natural. The new algorithms still maintain the optimal computational complexity as well as the second order accuracy. Numerical examples demonstrate the effectiveness of the proposed algorithms.  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