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   26930篇
  免费   1440篇
  国内免费   151篇
耳鼻咽喉   277篇
儿科学   555篇
妇产科学   641篇
基础医学   3460篇
口腔科学   1050篇
临床医学   1960篇
内科学   7247篇
皮肤病学   698篇
神经病学   2074篇
特种医学   497篇
外国民族医学   3篇
外科学   4373篇
综合类   176篇
一般理论   3篇
预防医学   1956篇
眼科学   444篇
药学   1494篇
中国医学   124篇
肿瘤学   1489篇
  2023年   211篇
  2022年   442篇
  2021年   961篇
  2020年   441篇
  2019年   892篇
  2018年   1037篇
  2017年   579篇
  2016年   589篇
  2015年   758篇
  2014年   1110篇
  2013年   1391篇
  2012年   2201篇
  2011年   2263篇
  2010年   1326篇
  2009年   1148篇
  2008年   1830篇
  2007年   1889篇
  2006年   1723篇
  2005年   1545篇
  2004年   1430篇
  2003年   1354篇
  2002年   1248篇
  2001年   162篇
  2000年   130篇
  1999年   168篇
  1998年   194篇
  1997年   154篇
  1996年   146篇
  1995年   128篇
  1994年   101篇
  1993年   84篇
  1992年   80篇
  1991年   58篇
  1990年   54篇
  1989年   44篇
  1988年   51篇
  1987年   37篇
  1986年   22篇
  1985年   39篇
  1984年   42篇
  1983年   44篇
  1982年   47篇
  1981年   48篇
  1980年   45篇
  1979年   22篇
  1978年   27篇
  1977年   27篇
  1975年   24篇
  1974年   21篇
  1973年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
From September 1984 to December 1989, 38 patients of pediatric age with localized bone sarcomas received intraoperative radiotherapy (IORT) as part of a multidisci plinary treatment program. The age ranged from 6 to 21 years. The tumor histologies were 22 osteosarcomas and 16 Ewing's sarcomas. Thirty-four had initial primary disease (90%) and 4 were treated for local recurrence (10%). IORT was used on 32 untreated patients and in 6 previously treated with external beam radiotherapy (EBR). The IORT field included the surgically exposed tumor bed area. Single radiation doses ranging from 10 to 20 Gy were delivered, using 6–20 MeV electron beams. The median follow-up time for the entire group is 25 months (2–65+ months). The projected 5-year disease-free and overall survival rates are 65% and 69%, respectively. One patient developed a local recurrence in each histological group: one chondroblastic osteosarcoma and one cervical Ewing's sarcoma. Six patients died from metastatic progression: 3 initially recurrent tumors and three primary disease cases. Severe neuropathy and soft tissue necrosis were seen in some patients as IORT related complications. IORT is a feasible technique to be integrated in multidisciplinary programs that may promote local control in pediatric and adolescent patients with bone sarcomas. Peripheral nerves are dose-limiting tissue structures for IORT.  相似文献   
52.
The authors' aim was to evaluate the range of uroflowmetry in diagnostics of stress urinary incontinence (sui) in women. The examinations were carried out in 59 women with sui, aged from 35 to 45 years (group I). The control group consisted of 20 asymptomatic women (group II). To evaluate volumes of urine voided during micturition in a unit of time a urological flowmeter UF-1 (produced by COTM, Bia?ystok) was used. Numeric data of flow were analysed, as well as registered curves of flow were ascribed to one of the following flow patterns: normal, multi-peak or interrupted. The conducted studies revealed statistically significant differences in flow values in group I, compared to group II. A more frequent incidence of multi-peak and interrupted flow patterns was found in women with sui, which could be related to a neurogenic component in etiology of the disease.  相似文献   
53.
54.
55.
56.
PURPOSE: A prospective radiographic study analyzed condylar position in patients who had undergone orthodontic treatment and isolated maxillary advancement after Le Fort I osteotomy. PATIENTS AND METHODS: Eleven patients were selected and radiographic images were taken in the immediate preoperative, immediate postoperative (1-2 weeks), and late postoperative periods (minimum of 6 months). Tracings were done on acetate paper for the submento-vertex radiograph, to measure the axial angulation of the condyles, and for the tomographic images of both sides, in the maximal intercuspation, rest position, and maximal opening, for the 3 periods. Linear measurements were taken for the tomograms over the posterior, superior, and anterior articular spaces. These images with the tracings were digitized and measured by means of computer software (UTHSCSA Image Tool 3.0; University of Texas Health Science Center at San Antonio, San Antonio, TX), after it had been adequately calibrated. RESULTS: The analysis of variance (ANOVA; 5% of significance) demonstrated 1) that there was no statistically significant difference for the linear measurements of the articular spaces in any of the periods, and 2) also not for the angular measure of the condyles (P > .05). In the maximal opening, there was a significant difference for the immediate postoperative period for both sides (P = .003). CONCLUSION: Le Fort I osteotomy for maxillary advancement did not cause any significant changes in this specific group of patients evaluated.  相似文献   
57.
PURPOSE: The aim of this study to analyze the preventive effect of high-dose infliximab in endotoxin-induced uveitis (EIU) in rabbits. METHODS: An experimental study was conducted on 64 rabbits. Salmonella typhimurium lipopolysaccharide endotoxin was intravitreally injected. Infliximab was intravenously (i.v.) injected 24 h before the intravitreal injection (20 mg/kg). The animals were randomly assigned to five groups: group A, saline intravitreal injection; group B, Infliximab i.v. group C, infliximab + saline; group D, intravitreal endotoxin and group E, infliximab i.v. + intravitreal endotoxin. With two masked observers, a microscopic examination of aqueous humor (cells, tumor necrosis factor [TNF] alpha) and aqueous protein level were performed 24 h after an endotoxin injection and 48 h after an infliximab infusion. RESULTS: Infliximab treatment, at a dose of 20 mg/kg, significantly improved all the parameters. Inflammatory cell infiltration was significantly reduced in the iris, ciliary body, and anterior chamber (U Mann-Whitney test, P = 0.01). Associated with a lower level of TNF-alpha and protein exudate in aqueous humor (U Mann-Whitney test, P = 0.01). CONCLUSIONS: Infliximab, at a dose of 20 mg/kg, is effective in the prophylaxis of the EIU.  相似文献   
58.
59.
60.
Cutaneous carcinoma histopathologically resembling nasopharyngeal carcinoma has been termed lymphoepithelioma-like carcinoma of the skin. We present an additional example of this rare cutaneous neoplasm that was located on the left temple of an 83-year-old woman. Serology for Epstein-Barr virus was negative, and exploration of the nasopharyngeal region disclosed no abnormalities. Histopathologically, the neoplasm consisted of a relatively well-circumscribed, dermal-hypodermal nodule composed of irregular aggregates of epithelial cells with vesicular nuclei, some of them in mitosis, and scant cytoplasm. A dense lymphocytic infiltrate was present within the neoplastic aggregates, obscuring the epithelial component, and at scanning magnification, the lesion closely resembled cutaneous lymphoma or pseudolymphoma. There was local sebaceous differentiation. Immunohistochemistry showed positivity in the epithelial component for AE1/AE3 and AEB-903 cytokeratins and negativity for 8–18 cylokeratins. The inflammatory infiltrate was positive for leukocyte common antigen, UCHL-1, L-26, Leu-22, and OPD-4 in variable proportions. Scattered cells within this inflammatory infiltrate were also positive for S-100 protein, vimentin, HAM-56, and MAC-387. In situ hybridization investigations for the presence of Epstein-Barr virus genomic DNA yielded negative results. Lymphoepithelioma-like carcinoma of the skin is a distinct cutaneous neoplasm of unknown histogenesis, although some foci of adnexal differentiation have been found in some specimens. The possibility of cutaneous metastasis from occult nasopharyngeal carcinoma should be ruled out.
Requena L, Sánchez Yus E, Jiménez E, Roo E. Lymphoepithelioma-like carcinoma of the skin: A light-microscopic and immunohistochemical study.  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