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   28662篇
  免费   2125篇
  国内免费   135篇
耳鼻咽喉   378篇
儿科学   734篇
妇产科学   627篇
基础医学   3873篇
口腔科学   851篇
临床医学   2343篇
内科学   7001篇
皮肤病学   669篇
神经病学   2631篇
特种医学   755篇
外国民族医学   1篇
外科学   4589篇
综合类   172篇
一般理论   9篇
预防医学   1897篇
眼科学   729篇
药学   1658篇
  1篇
中国医学   61篇
肿瘤学   1943篇
  2023年   177篇
  2022年   152篇
  2021年   895篇
  2020年   513篇
  2019年   831篇
  2018年   1040篇
  2017年   628篇
  2016年   708篇
  2015年   836篇
  2014年   1109篇
  2013年   1408篇
  2012年   2229篇
  2011年   2272篇
  2010年   1243篇
  2009年   1096篇
  2008年   1777篇
  2007年   1844篇
  2006年   1722篇
  2005年   1549篇
  2004年   1371篇
  2003年   1166篇
  2002年   1109篇
  2001年   428篇
  2000年   389篇
  1999年   393篇
  1998年   266篇
  1997年   225篇
  1996年   197篇
  1995年   212篇
  1994年   175篇
  1993年   159篇
  1992年   289篇
  1991年   237篇
  1990年   207篇
  1989年   213篇
  1988年   190篇
  1987年   149篇
  1986年   151篇
  1985年   139篇
  1984年   145篇
  1983年   105篇
  1982年   97篇
  1981年   86篇
  1980年   69篇
  1979年   92篇
  1978年   60篇
  1977年   57篇
  1976年   52篇
  1974年   61篇
  1973年   54篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
3.
4.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
5.
6.
7.
8.
PurposeBreast cancer is the most common cancer diagnosed during childbearing age, and fertility preservation is becoming increasingly more essential. However, recent studies indicate a possible poorer response to controlled ovarian hyperstimulation (COH) in cancer patients than in non-cancer controls and a negative impact of BRCA mutations on female fertility. This study aims to evaluate ovarian response and the number of mature oocytes (MII) vitrified in women with breast cancer, with or without BRCA mutation, comparing them to the expected response according to an age-related nomogram.MethodsThis is a retrospective observational study involving sixty-one breast cancer patients who underwent COH for oocyte cryopreservation. The age-specific nomogram was built using 3871 patients who underwent COH due to oocyte donation, fertility preservation for non-medical reasons, or FIVET for male factor exclusively.ResultsThe mean number of oocytes retrieved was 13.03, whereas the mean number of MII oocytes was 10.00. After the application of the z-score, no statistically significant differences were found compared with the expected response in the general population, neither by dividing patients according to the presence or absence of BRCA mutation nor according to the phase in which they initiated stimulation.ConclusionThe results obtained do not support the notion of a negative impact of the BRCA mutation on the ovarian response of women with breast cancer. Women with breast cancer undergoing COH for fertility preservation can expect the ovarian response predicted for their age.  相似文献   
9.
Classical Kaposi sarcoma (KS) usually appears on lower extremities accompanied or preceded by local lymphedema. However, the development in areas of chronic lymphedema of the arms following mastectomy, mimicking a Stewart–Treves syndrome, has rarely been described. We report an 81‐year‐old woman who developed multiple, erythematous to purple tumors, located on areas of post mastectomy lymphedema. Histopathological examination evidenced several dermal nodules formed by spindle‐shaped cells that delimitated slit‐like vascular spaces with some red cell extravasation. Immunohistochemically, the human herpesvirus type 8 (HHV‐8) latent nuclear antigen‐1 was detected in the nuclei of most tumoral cells confirming the diagnosis of KS. Lymphedema could promote the development of certain tumors by altering immunocompetence. Although angiosarcoma (AS) is the most frequent neoplasia arising in the setting of chronic lymphedema, other tumors such as benign lymphangiomatous papules (BLAP) or KS can also develop in lymphedematous limbs. It is important to establish the difference between AS and KS because their prognosis and treatment are very different. Identification by immunohistochemistry of HHV‐8 is useful for the distinction between KS and AS or BLAP.  相似文献   
10.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  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