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   2153篇
  免费   84篇
  国内免费   30篇
耳鼻咽喉   10篇
儿科学   49篇
妇产科学   31篇
基础医学   270篇
口腔科学   38篇
临床医学   217篇
内科学   425篇
皮肤病学   30篇
神经病学   164篇
特种医学   193篇
外科学   366篇
综合类   30篇
一般理论   1篇
预防医学   75篇
眼科学   60篇
药学   163篇
中国医学   2篇
肿瘤学   143篇
  2022年   10篇
  2021年   21篇
  2020年   12篇
  2019年   19篇
  2018年   28篇
  2017年   13篇
  2016年   38篇
  2015年   38篇
  2014年   41篇
  2013年   58篇
  2012年   78篇
  2011年   98篇
  2010年   47篇
  2009年   52篇
  2008年   86篇
  2007年   84篇
  2006年   104篇
  2005年   77篇
  2004年   61篇
  2003年   63篇
  2002年   61篇
  2001年   85篇
  2000年   65篇
  1999年   62篇
  1998年   32篇
  1997年   23篇
  1996年   38篇
  1995年   25篇
  1994年   47篇
  1993年   18篇
  1992年   45篇
  1991年   41篇
  1990年   56篇
  1989年   54篇
  1988年   64篇
  1987年   64篇
  1986年   66篇
  1985年   49篇
  1984年   21篇
  1983年   26篇
  1982年   24篇
  1981年   16篇
  1980年   13篇
  1979年   20篇
  1978年   17篇
  1977年   18篇
  1976年   18篇
  1975年   17篇
  1973年   13篇
  1972年   12篇
排序方式: 共有2267条查询结果,搜索用时 78 毫秒
1.
2.
It has been demonstrated that total parenteral nutrition (TPN) modulates the function of the hepatic reticuloendothelial system (RES). The objective of this study was to evaluate the impact of two different TPN lipid emulsions on the recovery of allograft RES function after orthotopic liver transplantation (OLTx). In a prospective, double-blind study, OLTx patients were randomly assigned to two treatment groups. Group I ( n=13) received a TPN regimen that included long-chain triglycerides (LCT). Group II ( n=9) received a TPN regimen that included a fat emulsion consisting of both medium-chain triglycerides (MCT) and LCT. At baseline, i.e., on days 2 or 3 after OLTx ( t1), before lipids for TPN were started, hepatic RES function was determined using the human serum albumin millimicrosphere technique (K-value, 1/min). A second measurement ( t2) was obtained after 7 days of TPN, including one of the study's two fat emulsions. The mean (+/- SD) K-value (1/min) was 0.48+/-0.16 in the LCT group and 0.55+/-0.28 in the MCT/LCT group at t1, and it improved to 0.62+/-0.21 in the LCT group and to 0.86+/-0.32 in the MCT/LCT group at t2. RES function recovery was significantly better in the MCT/LCT group ( P< or = 0.05). MCT/LCT emulsion appears to be the TPN fat emulsion of choice after OLTx as it seems to have less impact on hepatic RES recovery.  相似文献   
3.
4.
The isolated azygos continuation of the inferior vena cave is a very rare variation of this organ. It is accompanied by the absence of the retrohepatic segment of the vena cava with two new observations, the literature is revised and the origin discussed.  相似文献   
5.
Theodor Leber grew up in Heidelberg as the son of a professor of Romance languages. Initially he planned to study natural sciences. Bunsen's advice led him to medicine. During his studies he succeeded in solving a competition problem posed by Helmholtz in the medical department. A short period of practical work in the eye hospital of Knapp was unsatisfactory. In Vienna with the physiologist Carl Ludwig, he was able in 1863/64, at the age of only 24 years, to demonstrate the blood circulation of the eye by color injections into the arteries and veins. Since that time the schematic drawings of his results can be found in every textbook of ophthalmology. On the occasion of the congress of the German Ophthalmological Society in Heidelberg in 1864, Theodor Leber reported on these findings and met with immense approval. In 1864–67 he followed an invitation as coworker of Liebreich to Paris; in 1867 he became A.v. Graefe's coworker in Berlin; in 1871 he moved to Göttingen, which became the first eye clinic with a laboratory for experimental investigations.The second epoch-making discovery accomplished by Leber was the detection of the fluid exchange in the eye. These results have also been confirmed by modern methods. Therefore, Theodor Leber can be called the father of experimental ophthalmology.  相似文献   
6.
A study is reported of the utilization of non-clinical institutional care (geriatric and old people's homes) by the elderly inhabitants of Mannheim (pop. 306,000). The aim of the research was to establish the probability of admission to institutional care of an elderly person from this population, and to examine the influence of socio-demographic features. Under the West German health insurance system, most of the long-stay care of the elderly is provided not in hospitals but in nursing and geriatric homes. Data were collected on age at admission, place of residence before admission, duration of stay, age at death and place of death, as well as on the financial basis of care. The data were gathered retrospectively, the sample consisting of all inhabitants of Mannheim over 65 years old who died in the year 1982 (N = 2,585). At any given time only about four per cent of the elderly population will be in institutional care. In this respect, Mannheim is typical for the Federal Republic of Germany. However, the research findings demonstrate that approximately one elderly person in five will spend the last period of his life in this type of care. Seen in this light, the geriatric and old people's homes acquire a much greater social significance than is revealed by the number of institutional places alone.  相似文献   
7.
8.
The usefulness of indices commonly used in Doppler sonography is limited; the aim of this study was to investigate if inclusion of systolic acceleration and deceleration patterns in Doppler indices will result in practical diagnostic advantages. Systolic delay time index (SDTI) and height-width index (HWI) are compared to Gosling's pulsatility index (PI) and to PI-based damping factors (DF) in patients with isolated lesions in the distal superficial femoral artery before and after percutaneous transluminal angioplasty (PTA). Before PTA, all indices distal to the lesion differ significantly from proximal indices. After successful PTA, none of the indices is able to detect the PTA outcome with sufficient sensitivity. The additionally defined curve broadening index (CBI) shows a 100% sensitivity for detecting PTA success in the examined patient population.  相似文献   
9.
A 66-year-old man presented with bilateral subclavian steal syndrome (SSS) due to proximal subclavian artery occlusions. He was treated by percutaneous transluminal balloon angioplasty (PTA) and stent implantation in the left subclavian artery and by PTA alone in the right subclavian artery. We could demonstrate that interventional treatment of symptomatic bilateral SSS is possible. If PTA alone is insufficient, stent implantation should be considered.  相似文献   
10.
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