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   5529篇
  免费   404篇
  国内免费   31篇
耳鼻咽喉   38篇
儿科学   164篇
妇产科学   127篇
基础医学   816篇
口腔科学   174篇
临床医学   431篇
内科学   1321篇
皮肤病学   134篇
神经病学   719篇
特种医学   172篇
外科学   507篇
综合类   7篇
一般理论   1篇
预防医学   384篇
眼科学   63篇
药学   399篇
中国医学   15篇
肿瘤学   492篇
  2024年   10篇
  2023年   54篇
  2022年   120篇
  2021年   269篇
  2020年   149篇
  2019年   221篇
  2018年   234篇
  2017年   143篇
  2016年   208篇
  2015年   227篇
  2014年   277篇
  2013年   352篇
  2012年   521篇
  2011年   484篇
  2010年   276篇
  2009年   222篇
  2008年   323篇
  2007年   327篇
  2006年   341篇
  2005年   249篇
  2004年   261篇
  2003年   216篇
  2002年   174篇
  2001年   25篇
  2000年   26篇
  1999年   38篇
  1998年   42篇
  1997年   22篇
  1996年   23篇
  1995年   16篇
  1994年   15篇
  1993年   13篇
  1992年   12篇
  1991年   3篇
  1990年   10篇
  1989年   8篇
  1988年   12篇
  1987年   10篇
  1986年   3篇
  1985年   4篇
  1984年   8篇
  1983年   2篇
  1981年   2篇
  1980年   2篇
  1974年   1篇
  1970年   1篇
  1969年   1篇
  1946年   1篇
  1943年   1篇
  1921年   1篇
排序方式: 共有5964条查询结果,搜索用时 31 毫秒
81.
Hydroa Vaciniforme is a very rare photodermatosis that is mainly seen in childhood. An 18 year old female student reported that since the age of 5 she has been suffering necrotic lesions and vesicles lesions in exposed areas, leaving asymptomatic varioliform scars, which worsened in summer. Light microscopy showed epidermal necrosis with lymphocytic infiltration. Sunscreens were prescribed with light improvement.  相似文献   
82.
The aim of the present study was to evaluate the effects of a Global Postural Rehabilitation (GPR) program on motor symptoms and gait parameters of patients with Parkinson’s disease (PD) by means of three-dimensional motion analysis study. Ten subjects with clinical diagnosis of PD were enrolled (study group). Age-, sex- and disease duration-matched PD patients were recruited as a control group (no treatment). Three-dimensional motion analysis was conducted by means of a stereophotogrammetric system. After basal evaluation, the study group underwent a specific rehabilitation program consisting of individual 40?min GPR daily sessions, 3?days a week for 4 consecutive weeks. Neurological status and spatiotemporal gait parameters of the two groups were evaluated at study entry (t 0), at 4?weeks (t 1, end of rehabilitation protocol) and at 8 and 12?weeks (t 2 and t 3, follow-up evaluation). At baseline evaluation, the two groups did not differ in clinical features and gait parameters. At the end of rehabilitation protocol (t 1) and at follow-up evaluation (t 2 and t 3), a significant improvement in temporal gait parameters and UPDRS scores was observed in all treated patients as compared to baseline and controls. Our preliminary findings showed that significant improvements in mobility and gait parameters of PD patients can be obtained through GPR treatment, with a parallel improvement in clinical status. Quantitative analysis of gait pattern can be considered a useful tool to assess the efficacy of rehabilitation interventions in patients affected by PD.  相似文献   
83.
84.
85.
86.
A 67-year-old woman, who had symptoms of epigastric pain and abdominal distension, was found, on endoscopy, to have a large sessile villous adenoma of the periampullary duodenum. Despite the lack of evidence of malignancy, a pancreaticoduodenectomy procedure was performed, mainly because of the tumor size and site, involving the ampulla of Vater. The presence of the carcinoma was diagnosed only in the resected specimen by definitive histology. Because there is no general consensus on the optimal surgical procedure for the treatment of villous tumors of the duodenum, especially for the early stages, the indications for the operative procedure are discussed, based on a review of the literature.  相似文献   
87.
BACKGROUND: Clinical manifestations of dengue vary in different areas of endemicity and between specific age groups, whereas predictors of outcome have remained controversial. In Brazil, the disease burden predominantly affects adults, with an increasing trend toward progression to dengue hemorrhagic fever (DHF) noted. METHODS: A cohort of adults with confirmed cases of dengue was recruited in central Brazil in 2005. Patients were classified according to the severity of their disease. Associations of antibody responses, viremia levels (as determined by real-time polymerase chain reaction [PCR]), and serotypes (as determined by multiplex PCR) with disease severity were evaluated. RESULTS: Of the 185 symptomatic patients >14 years of age who had a confirmed case of dengue, 26.5% and 23.2% were classified as having intermediate dengue fever (DF)/DHF (defined as internal hemorrhage, plasma leakage, manifested signs of shock, and/or thrombocytopenia [platelet count, < or =50,000 platelets/mm3]) and DHF, respectively. The onset of intermediate DF/DHF and DHF occurred at a late stage of disease, around the period of defervescence. Patients with DHF had abnormal liver enzyme levels, with a >3-fold increase in aspartate aminotransferase level, compared with the range of values considered to be normal. Overall, 65% of patients presented with secondary infections with dengue virus, with such infection occurring in similar proportions of patients in each of the 3 disease category groups. Dengue virus serotype 3 (DV3) was the predominant serotype, and viremia was detected during and after defervescence among patients with DHF or intermediate DF/DHF. CONCLUSIONS: Viremia was detected after defervescence in adult patients classified as having DHF or intermediate DF/DHF. Secondary infection was not a predictor of severe clinical manifestation in adults with infected with the DV3 serotype.  相似文献   
88.
Cytomegalovirus (CMV) disease remains a severe complication in patients who have undergone transplantation. Viremia can be prevented and treated by the adoptive transfer of donor-derived CMV-directed T cells. To ensure long-term protection against CMV disease, it is important to transfer CMV antigen-specific T cells that represent both the CD8+ and the CD4+ subsets. In the present study, we used as stimulators dendritic cells (DCs) that were electroporated with in vitro-transcribed 5'-capped polyadenylated messenger RNA (mRNA) that encoded the CMV pp65 protein (i.e., pp65 mRNA). These DCs could efficiently activate CMV-directed CD8+ T cells, as assayed by tetramer staining, interferon- gamma production, and cytolytic activity. We also used DCs that were pulsed with a recombinant pp65 protein to activate CMV-directed CD4+ T cells. When DCs were comodified with pp65 mRNA and pp65 protein, large numbers of CMV-directed CD8+ and CD4+ T cells were generated simultaneously. The approach outlined in the present study can be adapted for a clinical protocol that circumvents potential virus-related biohazards and is available to all patients independently of their human leukocyte antigen haplotype.  相似文献   
89.
Non-myeloablative stem cell transplantation (NMT) has been increasingly used in compromised patients who would otherwise have been unable to undergo allotransplant. There is little understanding of the kinetics of immune reconstitution and its influence on infective complications following NMT. The aim of present study was to evaluate lymphocyte subset reconstitution over the first 12 months post-transplant in 15 adult patients receiving NMT with comparison to that of 30 patients grafted with a conventional hemopoietic stem cell transplantation (HSCT). NMT recipients were conditioned with fludarabine-based conditioning regimens. Peripheral blood stem cell (PBSC) was the source of stem cells in 13 NMT recipients and in 24 conventional HSCT recipients. Absolute numbers of helper (CD4+) T cells, naive (CD4+ CD45RA+) and memory (CD4+ CD45RO+) T cells as well as suppressor (CD8+) T cells, CD19+ B cells and NK cells were comparable in the two groups at all time points after transplantation. A median value of 200 CD4+ T cells/microl was achieved at 2 months post-transplant by the NMT and HSCT recipients. The CD4:CD8 ratio remained severely depressed throughout the study period. Almost all CD4+ lymphocytes expressed CD45RO antigen in the both groups of patients B lymphocytes showed low counts throughout the entire study period in both groups. Bacteremia and CMV antigenemia occurred respectively in 13 and 36% of the patients in the NMT group and in 15 and 39% of the patients in the HSCT group. Our preliminary data indicate that patients receiving a NMT have a lymphocyte reconstitution similar to that observed in patients who received a conventional HSCT. The incidence of bacteremia and CMV infection were not significantly different between the groups. Nevertheless, due to the small sample size, these results should be considered suggestive rather than definitive.  相似文献   
90.
Digestive Diseases and Sciences - Deregulation of immune response and oxidative stress contribute to nonalcoholic fatty liver disease (NAFLD) pathogenesis. Resistin is a physiological modulator of...  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