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   8256篇
  免费   609篇
  国内免费   14篇
耳鼻咽喉   142篇
儿科学   236篇
妇产科学   169篇
基础医学   1334篇
口腔科学   172篇
临床医学   692篇
内科学   1758篇
皮肤病学   219篇
神经病学   1006篇
特种医学   293篇
外国民族医学   4篇
外科学   921篇
综合类   60篇
一般理论   4篇
预防医学   543篇
眼科学   175篇
药学   524篇
中国医学   15篇
肿瘤学   612篇
  2023年   117篇
  2022年   163篇
  2021年   302篇
  2020年   210篇
  2019年   274篇
  2018年   307篇
  2017年   244篇
  2016年   296篇
  2015年   319篇
  2014年   347篇
  2013年   403篇
  2012年   658篇
  2011年   646篇
  2010年   334篇
  2009年   300篇
  2008年   471篇
  2007年   423篇
  2006年   398篇
  2005年   369篇
  2004年   290篇
  2003年   285篇
  2002年   245篇
  2001年   119篇
  2000年   94篇
  1999年   100篇
  1998年   52篇
  1997年   50篇
  1996年   41篇
  1995年   38篇
  1994年   36篇
  1993年   24篇
  1992年   62篇
  1991年   57篇
  1990年   56篇
  1989年   55篇
  1988年   54篇
  1987年   55篇
  1986年   45篇
  1985年   33篇
  1984年   26篇
  1983年   29篇
  1981年   25篇
  1979年   39篇
  1978年   16篇
  1976年   16篇
  1975年   18篇
  1974年   21篇
  1973年   18篇
  1971年   19篇
  1968年   17篇
排序方式: 共有8879条查询结果,搜索用时 421 毫秒
1.
2.
3.
4.
5.
The regrowth of amputated digit tips represents a unique regenerative healing in mammals with subcutaneous volume regrowth, restoration of dactylogram, and suppression of scar formation. Although factor analysis in amphibians and even in mice is easy to obtain, safety of harvesting biomaterial from human digit tip amputations for analysis has not yet been described.The aim of this study was to evaluate if recovering wound exudate does hamper clinical outcome or influence microbiologic or inflammation status.A predefined cohort of 18 patients with fresh digit tip amputations was randomly assigned to receive standard therapy (debridement, occlusive dressing) with (n = 9) or without (n = 9) collection of the whole wound exudate in every dressing change. Primary endpoint (lengthening) and secondary endpoints (regeneration of dactylogram, nail bed and bone healing, time to complete wound closure, scar formation, 2-point discrimination, microbiologic analysis, inflammatory factors interleukin (IL)-1α, tumor necrosis factor-α, IL-4, and IL-6) were determined by an independent, blinded observer.Patients’ characteristics showed no significant differences between the groups. All patients completed the study to the end of 3 months follow-up. Exudate collection did not influence primary and secondary endpoints. Furthermore, positive microbiologic findings as well as pus- and necrosis-like appearance neither impaired tissue restoration nor influenced inflammatory factor release.Here, the authors developed an easy and safe protocol for harvesting wound exudate from human digit tip amputations. For the first time, it was shown that harvesting does not impair regenerative healing. Using this method, further studies can be conducted to analyze regeneration associated factors in the human digit tip.DRKS.de Identifier: DRKS00006882 (UTN: U1111-1166-5723).  相似文献   
6.
Cornual, interstitial, and angular pregnancies are terms that are often used interchangeably in both the literature and clinical setting to describe various ectopic pregnancies. The diagnosis of these pregnancies can be difficult, and fear of disrupting an intrauterine pregnancy can cause hesitation during evaluation and management. In our 2 cases, a combination of transvaginal and 3-dimensional ultrasound images provided assistance in the accurate diagnosis of angular ectopic pregnancies. Traditional management of these pregnancies includes a wedge resection for pregnancy resolution. In this set of 2 cases, we describe a unique surgical approach to resolve these pregnancies using operative hysteroscopy.  相似文献   
7.
Antioxidant preservatives prolong the quality of food and ensure the nutritional adequacy, palatability and safety of many processed foods and beverages. Effects of sodium sulfite (E221) and sorbic acid (E200) were investigated in human peripheral blood mononuclear cells (PBMC) which were purified from blood of healthy donors. Cells were stimulated with the mitogen phytohaemagglutinin in vitro, which induces proliferation of T-cells and the production of Th1-type cytokines like interferon-γ. The latter triggers enzyme indoleamine (2,3)-dioxygenase, which degrades tryptophan, and GTP cyclohydrolase I, which leads to increased neopterin production, in monocyte-derived macrophages. Sodium sulfite and sorbic acid suppressed both these biochemical changes in a dose-dependent way (P < 0.01 at 1 mM sodium sulfite and 50 mM sorbic acid). Data demonstrate a suppressive influence of sodium sulfite and sorbic acid on the activated Th1-type immune response.  相似文献   
8.
BACKGROUND: Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. METHODS: Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. RESULTS: Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 +/- 0.9 vs 3.21 +/- 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 +/- 2.9 vs 2.37 +/- 2.9 mm(2), p = 0.004) and total vessel area (18.36 +/- 5.8 vs 12.81 +/- 4.8 mm(2), p = 0.012) than those with normal plasma concentrations. CONCLUSIONS: Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation.  相似文献   
9.
Katharina Pachmann 《Clinical cancer research》2005,11(15):5657; author reply 5657-5657; author reply 5658
  相似文献   
10.
Lung cancer is the leading cause of cancer deaths in both men and women in the United States. Treatment depends on the type and stage of lung cancer. For stage I and II cancer, surgery is usually the treatment of choice. Radiation therapy is used in patients who are considered poor risks for surgical resection. Intraoperative brachytherapy is an effective alternative to external irradiation in this group of patients. From 1958 to 1984, 55 patients with non-small-cell lung cancer were explored at Memorial Sloan Kettering Cancer Center and found to have surgical stage I or II tumors, which were considered to be unresectable mainly because of severe obstructive pulmonary disease precluding adequate resection. All these patients were treated with intraoperative brachytherapy at the time of the thoracotomy. Forty-four percent of these patients received in addition external irradiation, mainly to the mediastinum. The overall 5-year survival calculated by the Kaplan-Meier Method was 32%, and the local disease-free survival was 63%. Cox regression multivariant analysis demonstrated that there is a distinct subgroup with a better prognosis based on tumor site and patient's age--ie, patients who were younger than 58 years of age and had right-side lesions.  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