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   2486篇
  免费   131篇
  国内免费   13篇
耳鼻咽喉   34篇
儿科学   209篇
妇产科学   47篇
基础医学   366篇
口腔科学   62篇
临床医学   158篇
内科学   460篇
皮肤病学   26篇
神经病学   118篇
特种医学   62篇
外科学   474篇
综合类   39篇
预防医学   92篇
眼科学   118篇
药学   213篇
中国医学   12篇
肿瘤学   140篇
  2025年   4篇
  2024年   20篇
  2023年   25篇
  2022年   45篇
  2021年   114篇
  2020年   58篇
  2019年   78篇
  2018年   77篇
  2017年   54篇
  2016年   82篇
  2015年   94篇
  2014年   120篇
  2013年   129篇
  2012年   231篇
  2011年   243篇
  2010年   126篇
  2009年   98篇
  2008年   180篇
  2007年   141篇
  2006年   129篇
  2005年   121篇
  2004年   118篇
  2003年   97篇
  2002年   64篇
  2001年   15篇
  2000年   9篇
  1999年   7篇
  1998年   23篇
  1997年   17篇
  1996年   10篇
  1995年   8篇
  1994年   5篇
  1993年   11篇
  1992年   11篇
  1991年   7篇
  1989年   5篇
  1988年   7篇
  1987年   6篇
  1986年   3篇
  1985年   2篇
  1984年   3篇
  1982年   3篇
  1981年   7篇
  1980年   5篇
  1976年   3篇
  1975年   2篇
  1973年   3篇
  1972年   2篇
  1962年   1篇
  1940年   1篇
排序方式: 共有2630条查询结果,搜索用时 15 毫秒
21.
22.
Scar ectopic pregnancy is the rarest form of ectopic pregnancy and has been increasingly diagnosed all over the world. This is a life-threatening form of abnormal implantation of embryo within the myometrium and fibrous tissues in a previous scar on the uterus, especially following caesarean section. With the increasing rate of caesarean section, there is a substantial increase in this condition with better understanding of this disease. The early and accurate diagnosis with timely management can prevent pregnancy complications such as haemorrhage, uterine rupture and can preserve fertility.  相似文献   
23.
24.
25.

Purpose of the Study:

It is difficult to achieve a reliable bond between the titanium and veneering porcelain. The aim of this study was to evaluate the bond strength between titanium ceramic crowns.

Materials and Methods:

The surfaces of titanium copings were divided in two groups. Group A sandblasted with 250 um (n = 10) and Group B without sandblasting (n = 10). Low-fusing porcelain was bonded over copings. A universal testing machine was used to determine the fracture load (N) of the crowns. All data were compared using Student''s t-test.

Results:

There was a significant difference in fracture toughness between two groups (P = 0.05). The mean value of fracture strength for Group A was 721.66 N and for Group B was 396.39 N.

Conclusions:

Sandblasting improves the bond strength between titanium, and ceramic, mechanical bonding plays a crucial role in the bonding between titanium and ceramic.Key Words: Bonding, fracture load, sandblasting, titanium  相似文献   
26.
Widespread emergence of multidrug resistant (MDR) bacterial pathogens is a problem of global dimension. MDR infections are difficult to treat and frequently associated with high mortality. More than one antibiotic is commonly used to treat such infections, but scientific evidence does not favor use of combination therapy in most cases. However, there are certain subgroups where combination therapy may be beneficial, e.g. sepsis due to carbapenem-resistant Enterobacteriaceae (CRE), bacteremic pneumococcal pneumonia, and patients with multiple organ failure. Well-designed prospective studies are needed to clearly define the role of combination therapy in these subgroups.  相似文献   
27.

Background

Perinatal asphyxia is known to precipitate myocardial dysfunction, rhythm abnormalities and congestive cardiac failure.

Case characteristics

A 2-day old neonate with perinatal asphyxia.

Observation

He developed shock secondary to ventricular tachycardia, and required synchronized cardioversion for reversion of abnormal rhythm.

Outcome

Reversal of arrhythmia leading to recovery.

Message

Early identification and management of ventricular tachycardia in neonate with perinatal asphyxia can be lifesaving.  相似文献   
28.
The development of accurate, minimally invasive continuous glucose monitoring (CGM) devices has been the subject of much work by several groups, as it is believed that a less invasive and more user-friendly device will result in greater adoption of CGM by persons with insulin-dependent diabetes. This article presents the results of preliminary clinical studies in subjects with diabetes of a novel prototype microneedle-based continuous glucose monitor. In this device, an array of tiny hollow microneedles is applied into the epidermis from where glucose in interstitial fluid (ISF) is transported via passive diffusion to an amperometric glucose sensor external to the body. Comparison of 1396 paired device glucose measurements and fingerstick blood glucose readings for up to 72-hour wear in 10 diabetic subjects shows the device to be accurate and well tolerated by the subjects. Overall mean absolute relative difference (MARD) is 15% with 98.4% of paired points in the A+B region of the Clarke error grid. The prototype device has demonstrated clinically accurate glucose readings over 72 hours, the first time a microneedle-based device has achieved such performance.  相似文献   
29.
Genetic variation in the IL-7 receptor-α (IL-7R) gene is associated with susceptibility to human type 1 diabetes (T1D). Here we investigate the therapeutic efficacy and mechanism of IL-7Rα antibody in a mouse model of T1D. IL-7Rα antibody induces durable, complete remission in newly onset diabetic mice after only two to three injections. IL-7 increases, whereas IL-7Rα antibody therapy reduces, the IFN-γ-producing CD4(+) (T(H)1) and IFN-γ-producing CD8(+) T cells. Conversely, IL-7 decreases and IL-7Rα antibody enhances the inhibitory receptor Programmed Death 1 (PD-1) expression in the effector T cells. Programmed Death 1 blockade reversed the immune tolerance mediated by the IL-7Rα antibody therapy. Furthermore, IL-7Rα antibody therapy increases the frequency of regulatory T cells without affecting their suppressor activity. The durable efficacy and the multipronged tolerogenic mechanisms of IL-7Rα antibody therapy suggest a unique disease-modifying approach to T1D.  相似文献   
30.
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