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   5132篇
  免费   407篇
  国内免费   12篇
耳鼻咽喉   25篇
儿科学   103篇
妇产科学   304篇
基础医学   1031篇
口腔科学   44篇
临床医学   409篇
内科学   837篇
皮肤病学   301篇
神经病学   569篇
特种医学   253篇
外科学   530篇
综合类   33篇
一般理论   4篇
预防医学   293篇
眼科学   96篇
药学   250篇
中国医学   4篇
肿瘤学   465篇
  2022年   42篇
  2021年   58篇
  2020年   45篇
  2019年   69篇
  2018年   72篇
  2017年   72篇
  2016年   82篇
  2015年   124篇
  2014年   151篇
  2013年   162篇
  2012年   240篇
  2011年   248篇
  2010年   157篇
  2009年   162篇
  2008年   278篇
  2007年   261篇
  2006年   266篇
  2005年   246篇
  2004年   248篇
  2003年   198篇
  2002年   226篇
  2001年   185篇
  2000年   172篇
  1999年   138篇
  1998年   63篇
  1997年   72篇
  1996年   50篇
  1995年   65篇
  1994年   40篇
  1993年   32篇
  1992年   76篇
  1991年   70篇
  1990年   76篇
  1989年   74篇
  1988年   51篇
  1987年   55篇
  1986年   50篇
  1985年   57篇
  1984年   36篇
  1983年   31篇
  1982年   27篇
  1979年   42篇
  1978年   33篇
  1976年   30篇
  1975年   26篇
  1974年   33篇
  1973年   44篇
  1972年   25篇
  1971年   33篇
  1970年   29篇
排序方式: 共有5551条查询结果,搜索用时 15 毫秒
1.
Constitutional trisomy 21 is the most prominent predisposing factor to childhood leukemia, whereas the t(12;21)(p13;q22) with its molecular genetic counterpart, the TEL/AML1 fusion gene, is the most common acquired chromosomal rearrangement in childhood B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). Thus, it was somewhat surprising that according to the currently available literature the incidence of TEL/AML1+ BCP ALL is extremely low in patients with Down syndrome (DS). To further investigate this issue in a population-based fashion, the authors retrospectively assessed the number of DS patients with a TEL/AML1+ ALL in two consecutive Austrian ALL multicenter trials. Accordingly, they were able to analyze 8 of 10 individuals with DS and a BCP ALL, including 2 who suffered from a TEL/AML1+ leukemia. Based on this observation we concluded that individuals with a constitutional trisomy 21 may have the similar likelihood to develop a TEL/AML1+ leukemia as BCP ALL patients without this specific predisposing factor.  相似文献   
2.
3.
Several cases of relapsing attacks during which the ear becomes red and patients experience a burning sensation have been reported in the literature. This combination of symptoms has been described as ‘red ear syndrome’ (RES). We report on a 7‐year‐old boy who had episodes of reddening, swelling and a burning sensation in one ear with local hyperthermia persisting for 3 years. The differential diagnosis included RES and erythromelalgia, as isolated auricular variants of erythromelalgia have been described and the symptoms are difficult to distinguish from RES. In this report, we discuss the similarities and differences between RES and erythromelalgia.  相似文献   
4.
The role of timing of transplant nephrectomy after renal transplantation has not been well defined. This report compares the morbidity, mortality, and hospitalization costs of 37 patients undergoing transplant nephrectomy within 14 days after graft failure and return to dialysis, with 31 patients undergoing delayed transplant nephrectomy (less than 14 days after graft failure and return to dialysis). This analysis revealed that there were no significant (P greater than .05) differences in patient morbidity and mortality between these groups. There was, however, a substantial increase (P less than .05) in the cost of hospitalization in the delayed nephrectomy group. For this reason, we recommend early nephrectomy after renal transplant failure in order to minimize the cost of health care for these patients undergoing failed cadaver donor transplant nephrectomy.  相似文献   
5.
The state of pregnancy is an immunological enigma during which the body must prevent rejection of the antigenically foreign fetus while at the same time maintain sufficient maternal host defense mechanisms to combat infection. Although most studies on the immunology of pregnancy focus on immune suppression, several studies have shown an increase in nonspecific host defense, which is postulated to be a compensatory mechanism for decreased specific immunity during pregnancy. Studies in this laboratory have shown that monocyte surface FcγRI (CD64) and FcγRII (CD32) expression progressively increase throughout pregnancy, while surface MHC class II expression remains unchanged. Functional studies revealed that the number of phagocytic monocytes which could be isolated from pregnant women was increased. These cells exhibited an increased capacity to ingest IgG-opsonized human erythrocytes. This study shows for the first time that monocyte surface FcγR expression and FcγR-mediated functions are increased during pregnancy. These results support the hypothesis that nonspecific immunity as represented by FcγR expression and function is increased during pregnancy.  相似文献   
6.
AIMS: DDD-pacemakers are favoured in patients with sick-sinus-syndrome or AV-block. However, AAI-pacemakers for sick-sinus-syndrome or VDD-pacemakers for AV-block may provide similar benefit with lower costs. The aim is to show that a tailored approach (TA) with arrhythmia-specific pacemaker selection was equal to a standard approach (SA) regarding quality of life (QoL) at lower costs. METHODS AND RESULTS: The study was prospective and randomized with QoL as primary endpoint. Secondary endpoints were a combined endpoint of all-cause mortality, worsening heart failure or angina, atrial fibrillation (AF), stroke, these endpoints individually and costs. Of 198 patients (age 77 +/- 10 years, 43% female, ejection fraction 54 +/- 12%, follow-up 38 +/- 15 months), 94 were randomized to SA and 104 to TA. Thirty-two patients (34%) died in the SA group vs. 25 (24%) in the TA (P= ns). QoL showed no differences in all dimensions. The combined secondary endpoint was reached more frequently with SA (51%) compared to TA (37%, P = 0.045). There was no difference regarding all single secondary endpoints. Hardware costs were reduced by 15% (P < 0.0001). CONCLUSION: In long-term follow-up, a TA is equal to SA regarding the primary endpoint QoL and secondary endpoints as AF and mortality. Depending on the healthcare system, it may significantly reduce costs.  相似文献   
7.
One of the characteristics of breast cancer is its hormone dependency, which provides a number of effective approaches for treatment. Endocrine therapies usually have a good tolerability and oral application is convenient. Third generation aromatase inhibitors are well established in the treatment of metastatic breast cancer, having overtaken Tamoxifen. In the adjuvant setting, the ATAC trial is beginning to demonstrate the superiority of anastrozol compared to Tamoxifen. A new set of trials, coordinated by the International Breast Intervention Study Group, will compare the anti-hormones in healthy postmenopausal women with a moderate risk of developing breast cancer and in women after surgery for ductal carcinoma in situ. This article will discuss the various options for endocrine therapy in metastatic breast disease. The indications for endocrine manipulation as well as the various drugs will be discussed.  相似文献   
8.
Ohne Zusammenfassung Rechtsreferendar Mario Kaufmann, Wiss. Hilfskraft am Lehrstuhl für V?lkerrecht, Europarecht, Europ?isches und Internationales Wirtschaftsrecht (Prof. Dr. Stephan Hobe) an der Universit?t zu K?ln, Neusser Stra?e 285, D-50733 K?ln  相似文献   
9.
New approach in strabismus surgery in high myopia   总被引:8,自引:0,他引:8       下载免费PDF全文
AIMS—To develop appropriate methods of eye muscle surgery in highly myopic patients with esotropia and hypotropia, with respect to the pathological findings in high resolution magnetic resonance imaging (MRI).
METHODS—35 patients with unilateral or bilateral high myopia and strabismus—that is, axial length of the globe averaged 29.4 mm. Multiple coronal, transverse, and parasagittal MRI image planes were obtained using a Siemens Magnetom 1.5 tesla MRI scanner. In 15 patients with a pathological plane of recti extraocular muscles found by MRI and confirmed intraoperatively, a new technique of eye muscle surgery was performed to re-establish the physiological muscle plane. This was checked postoperatively in addition to the measurement of alignment and motility by MRI.
RESULTS—The new MRI finding of a dislocation of the lateral rectus (LR) into the temporocaudal quadrant by 3.4 mm requires new surgical techniques. Only fixing the LR in the physiological meridian at the equator with a silicone loop (`guide pulley') or a non-absorbable suture is a causal therapy. This yields alignment and improves abduction and elevation.
CONCLUSIONS—If the described misalignment of the LR is detected by MRI, a common high dosage recess-resect procedure for esotropia may even aggravate the deviation. The most important aim of eye muscle surgery is to normalise the pathological path of the LR. The restoration of the physiological function of the dislocated LR is remarkable.

  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