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   66322篇
  免费   4595篇
  国内免费   1807篇
耳鼻咽喉   441篇
儿科学   963篇
妇产科学   622篇
基础医学   7647篇
口腔科学   1095篇
临床医学   6105篇
内科学   6745篇
皮肤病学   374篇
神经病学   8711篇
特种医学   2075篇
外国民族医学   2篇
外科学   4751篇
综合类   10516篇
现状与发展   6篇
预防医学   9598篇
眼科学   690篇
药学   7667篇
  97篇
中国医学   2312篇
肿瘤学   2307篇
  2024年   79篇
  2023年   950篇
  2022年   1366篇
  2021年   2406篇
  2020年   2457篇
  2019年   1884篇
  2018年   1875篇
  2017年   1887篇
  2016年   2101篇
  2015年   2093篇
  2014年   4288篇
  2013年   4653篇
  2012年   4110篇
  2011年   4525篇
  2010年   3535篇
  2009年   3424篇
  2008年   3528篇
  2007年   3351篇
  2006年   3021篇
  2005年   2570篇
  2004年   2160篇
  2003年   1886篇
  2002年   1463篇
  2001年   1269篇
  2000年   1082篇
  1999年   866篇
  1998年   807篇
  1997年   772篇
  1996年   640篇
  1995年   692篇
  1994年   681篇
  1993年   579篇
  1992年   556篇
  1991年   539篇
  1990年   443篇
  1989年   398篇
  1988年   410篇
  1987年   383篇
  1986年   354篇
  1985年   478篇
  1984年   411篇
  1983年   253篇
  1982年   283篇
  1981年   259篇
  1980年   240篇
  1979年   150篇
  1978年   146篇
  1977年   127篇
  1976年   91篇
  1974年   49篇
排序方式: 共有10000条查询结果,搜索用时 46 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.
In patients treated by orbital wall decompression for endocrine orbitopathy (EO) there is limited evidence on the effect of orbital wall resections. Thus, the aim of this study was to evaluate the effect of one, two, and three-wall resections on orbital parameters to determine if any such correlations exist. Preoperative and postoperative data from all patients at a tertiary care centre who underwent decompression surgery from 2010 - 2020 were digitally analysed. The effect of the number and area of resected walls on orbital area, orbital volume, and Hertel value, and the effect of lateral rim advancement (LARA) were determined. A total of 131 orbital areas showed an increase from a mean (SD) preoperative area of 42.0 (4.6) cm2 to 47.3 (6.1) cm2 postoperatively (p<0.001). In total, the mean (SD) area of osseous wall removed in all patients was 6.2 (1.7) cm2 at the lateral orbit (n = 129), 6.7 (2.3) cm2 at the orbital floor (n = 123), and 5.8 (1.8) cm2 at the medial orbital wall (n =30). The mean (SD) orbital volume increased by 6.0 (3.0) cm3 after decompression. There was also a significant reduction in exophthalmos of 7.3 (3.2) mm (from 25.2 (3.9) to 17.9 (3.5), p<0.001). LARA was performed in 50 patients. Changes in volume and area, and reduction in exophthalmos were not significantly different with or without LARA. The postoperative effects of orbital wall resection are predictable and exhibit a relation with six units of change. Two-wall resection is the most common intervention.  相似文献   
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.
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   
8.
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   
9.
《Cancer radiothérapie》2022,26(4):547-556
PurposeSurface-guided radiotherapy is useful for the pre-positioning and monitoring of radiotherapy. The purpose of this study was to investigate the impact of surface guidance on the repeatability of patient localization and to estimate the specific point at which high positional errors occur.Materials and methodsTen patients without the VOXELAN system (non-VXLN group) and 10 patients with the VOXELAN as the pre-positioning procedure (VXLN group) were included in this analysis. Twelve regions of interest (ROI) were defined in all the patients to verify any misalignment during radiotherapy. Thirteen ROIs were defined on the isocenter.ResultsCompared with the non-VXLN group, the translational positional errors of the VXLN group were the same for all the ROIs. The mean translational positional errors of the VXLN group in the longitudinal direction were approximately 0.1 mm, and the standard deviation was the largest among the three directions in all the ROIs. The magnitude of the standard deviation in the non-VXLN group varied independently of the ROI and direction. The standard deviations of the VXLN group in the longitudinal direction were large in all the ROIs, while the standard deviations in the vertical and lateral directions were small.ConclusionPre-positioning with a surface guidance system reduced the body twist and rotation, which could not be corrected by image-guided radiotherapy alone. Since the VOXELAN can detect positioning errors quickly and without additional radiation exposure to the patient, it can be used as a tool for pre-positioning in radiotherapy.  相似文献   
10.
The circadian rhythm in humans is determined by the central clock located in the hypothalamus’s suprachiasmatic nucleus, and it synchronizes the peripheral clocks in other tissues. Circadian clock genes and clock-controlled genes exist in almost all cell types. They have an essential role in many physiological processes, including lipid metabolism in the liver, regulation of the immune system, and the severity of infections. In addition, circadian rhythm genes can stimulate the immune response of host cells to virus infection. Hepatitis B virus (HBV) infection is the leading cause of liver disease and liver cancer globally. HBV infection depends on the host cell, and hepatocyte circadian rhythm genes are associated with HBV replication, survival, and spread. The core circadian rhythm proteins, REV-ERB and brain and muscle ARNTL-like protein 1, have a crucial role in HBV replication in hepatocytes. In addition to influencing the virus’s life cycle, the circadian rhythm also affects the pharmacokinetics and efficacy of antiviral vaccines. Therefore, it is vital to apply antiviral therapy at the appropriate time of day to reduce toxicity and improve the effectiveness of antiviral treatment. For these reasons, understanding the role of the circadian rhythm in the regulation of HBV infection and host responses to the virus provides us with a new perspective of the interplay of the circadian rhythm and anti-HBV therapy. Therefore, this review emphasizes the importance of the circadian rhythm in HBV infection and the optimization of antiviral treatment based on the circadian rhythm-dependent immune response.  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