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   618篇
  免费   43篇
  国内免费   15篇
耳鼻咽喉   4篇
儿科学   42篇
妇产科学   3篇
基础医学   65篇
口腔科学   12篇
临床医学   65篇
内科学   127篇
皮肤病学   16篇
神经病学   11篇
特种医学   117篇
外科学   36篇
综合类   107篇
预防医学   28篇
眼科学   2篇
药学   19篇
中国医学   1篇
肿瘤学   21篇
  2023年   2篇
  2022年   3篇
  2021年   9篇
  2020年   3篇
  2019年   6篇
  2018年   4篇
  2017年   8篇
  2016年   9篇
  2015年   17篇
  2014年   23篇
  2013年   16篇
  2012年   28篇
  2011年   15篇
  2010年   31篇
  2009年   33篇
  2008年   32篇
  2007年   22篇
  2006年   12篇
  2005年   9篇
  2004年   7篇
  2003年   9篇
  2002年   8篇
  2001年   14篇
  2000年   7篇
  1999年   16篇
  1998年   46篇
  1997年   40篇
  1996年   31篇
  1995年   19篇
  1994年   27篇
  1993年   22篇
  1992年   5篇
  1991年   7篇
  1990年   5篇
  1989年   12篇
  1988年   12篇
  1987年   25篇
  1986年   8篇
  1985年   12篇
  1984年   4篇
  1983年   7篇
  1982年   14篇
  1981年   5篇
  1980年   5篇
  1979年   1篇
  1978年   8篇
  1977年   4篇
  1976年   8篇
  1975年   5篇
  1967年   1篇
排序方式: 共有676条查询结果,搜索用时 15 毫秒
161.
A new cell line, NCEB-1, was established by Epstein-Barr virus (EBV) transformation of peripheral blood mononuclear cells from a patient with centroblastic-centrocytic diffuse lymphoma expressing IgM lambda. The transformed cells were lymphoblastoid, with many cells showing a plasmacytoid morphology. The NCEB-1 cells had cytoplasmic Ig (CyIg), with loss of the surface Ig (SIg) expression. Cytogenetic analysis of the cell line demonstrated two clones with variations: a hypodiploid clone, with a complex karyotype including a t(11;14)(q13;q32) similar to the original tumor cells, and a near tetraploid clone with the same markers. Southern blot analysis of DNA from the patient's neoplastic cells and NCEB-1 demonstrated identical Ig heavy chain gene rearrangement, confirming the origin of the cell line. The cell line was not tumorigenic when tested in an in vitro assay using immunosuppressed mice. NCEB-1 has been in continuous culture for 9 months and will be valuable for the in vivo study of non-Hodgkin's lymphoma and EBV transformation.  相似文献   
162.
163.
164.
165.
One hundred and twenty-eight patients with non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD), and acute lymphoblastic leukemia (ALL) previously reported from a phase III trial of rhGM-CSF or placebo following autologous bone marrow transplantation (ABMT) were investigated for the development of late toxicities. Median follow-up is 36 months. No apparent long-term deleterious effects on BM function were observed. Moreover, disease-free survival and overall survival were similar for patients on both treatment arms, arguing for the long- term safety of recombinant human granulocyte macrophage-colony- stimulating factor (rhGM-CSF). The only factors predictive for both a high risk of relapse over time and mortality were having the diagnosis of ALL and/or undergoing ABMT in resistant relapse. We attempted to identify clinical variables before BM harvest, at the time of marrow infusion, or events within the first 100 days posttransplant, which might predict speed of neutrophil recovery in the setting of placebo or rhGM-CSF administration after ABMT. Only previous exposure to agents that deplete stem cells led to a significant delay in neutrophil recovery, suggesting their avoidance in patients who may undergo ABMT. Nevertheless, even those patients benefited from rhGM-CSF. For all patients, rhGM-CSF and agents that deplete stem cells were the strongest independent predictors for neutrophil engraftment. With the increasing use of newer hematopoietic growth factors both alone and in combination, long-term follow-up is essential to confirm the same safety that we report with rhGM-CSF.  相似文献   
166.
BACKGROUND & AIMS: Nonsteroidal anti-inflammatory drugs (NSAIDs) are strongly associated with gastroduodenal ulceration. How to manage patients with NSAID-associated ulcers is a common clinical dilemma. High-dose famotidine in the healing and maintenance of NSAID-associated gastroduodenal ulceration was therefore evaluated. METHODS: One hundred four patients with rheumatoid or osteoarthritis who had gastroduodenal ulceration received famotidine, 40 mg twice daily. Sixteen patients stopped and 88 continued their NSAID treatment. Ulcer healing was assessed endoscopically at 4 and 12 weeks. Seventy-eight NSAID users with healed ulcers were then randomized to receive 40 mg twice daily famotidine or placebo and underwent endoscopy at 4, 12, and 24 weeks. RESULTS: Cumulative ulcer healing rates at 12 weeks were 89.0% (95% confidence interval [CI], 82.3%-95.7%) for patients who continued NSAID treatment and 100% (95% CI, 82.9%-100.0%) for those who stopped. The subsequent estimated cumulative gastroduodenal ulcer relapse over 6 months for NSAID users who took placebo was 53.5% (95% CI, 36.6%- 70.3%). This was reduced to 26.0% (12.1%-39.9%) in patients taking famotidine (P = 0.011). CONCLUSIONS: High-dose famotidine is effective ulcer healing therapy in patients who stop or continue NSAID treatment and significantly reduced the cumulative incidence of gastroduodenal ulcer recurrence compared with placebo when given as maintenance therapy. (Gastroenterology 1997 Jun;112(6):1817-22)  相似文献   
167.
168.
169.
Immunologic characterization of a helper T-cell lymphoma   总被引:3,自引:0,他引:3  
The lymphocytes of a patient with a T-cell non-Hodgkin's lymphoma with peripheral blood involvement and polyclonal hypergammaglobulinemia were characterized in terms of surface markers and immunologic functions. Using the fluorescence-activated cell sorter and employing various monoclonal antibodies against T-cell surface antigens, it was shown that almost all of the patient's peripheral blood lymphocytes were positive for OKT4 and 9.3, antibodies that recognize helper T-cell subset. The circulating lymphoma cells had typical characteristics for T cells; they formed spontaneous rosettes with sheep erythrocytes and stained with the pan-T-cell antibodies 9.6 and 10.2, but did not react with other anti-T-cell monoclonal reagents such as OKT3, UCHT-1, and 3A1. The cells appeared to be mature by the fact that they did not stain with OKT6, and terminal deoxynucleotidyl transferase was undetectable. Functionally, they were able to provide "help" for antibody production, and they could be stimulated to produce moderate amounts of interleukin-2, while unable to proliferate in response to mitogens. Morphologically, some of the lymphocytes showed a deeply cleaved nucleus.  相似文献   
170.
Eight-five consecutive patients with relapsed or refractory Hodgkin's disease (HD) underwent high-dose chemotherapy or chemo/radiotherapy followed by autologous bone marrow (ABMT) and/or peripheral blood stem cell (PBSC) transplantation. Two preparative regimens were used. Twenty- two patients (26%) without prior radiation received fractionated total body irradiation (FTBI) 1,200 Gy in combination with high-dose etoposide (VP-16) 60 mg/kg and cyclophosphamide (CTX) 100 mg/kg. Sixty- three patients (74%) with prior radiotherapy received carmustine (BCNU) 450 mg/m2 instead of FTBI. The median age was 32 years (range, 16 to 56). The median number of prior chemotherapy regimens was three (range, 1 to 7). Forty-three patients (51%) received transplants in first relapse or second complete remission (CR), whereas 33 (39%) received transplants after second or subsequent relapse. All relapsed patients, except one, received conventional salvage chemotherapy and/or radiotherapy in an attempt to reduce tumor bulk before transplant. At the time of analysis in April 1994, fifty-seven patients (67%) are alive, including 44 (52%) in continuous CR, with a median follow-up for the surviving patients of 28 months (range, 7 to 66). Thirty patients (35%) relapsed at a median of 9 months (range, 1 to 43). Eleven patients (13%) died of transplant-related complications including veno- occlusive disease of the liver (VOD) in five, acute and late interstitial pneumonitis in three, graft failure in one, cerebral hemorrhage in one, and therapy-induced myelodysplasia (MDS)/acute leukemia in one patient. At a median follow-up of 25 months (range, 0.6 to 66), the cumulative probability of 2-year overall and disease-free survival (DFS) of all 85 patients is 75% (95% confidence interval [CI] 64% to 84%) and 58% (95% CI 47% to 69%), respectively. Three independent prognostic variables were identified by univariate analysis: number of prior chemotherapy regimens, prior radiotherapy, and extranodal disease at ABMT. Multivariate stepwise Cox regression identified the number of prior chemotherapy regimens as the only significant prognostic factor predicting for both relapse and DFS. There were no significant differences in the outcome of the treatment between the two preparative regimens. Our results confirm that high- dose therapy and ABMT is an effective therapy for patients with relapsed or refractory HD. Earlier transplantation is recommended before the development of drug resistance and end organ damage that results from repeated attempts of salvage therapy.  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