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   2599篇
  免费   100篇
  国内免费   11篇
耳鼻咽喉   83篇
儿科学   91篇
妇产科学   126篇
基础医学   330篇
口腔科学   34篇
临床医学   154篇
内科学   655篇
皮肤病学   44篇
神经病学   267篇
特种医学   46篇
外科学   170篇
综合类   17篇
预防医学   210篇
眼科学   59篇
药学   276篇
中国医学   2篇
肿瘤学   146篇
  2023年   14篇
  2022年   104篇
  2021年   125篇
  2020年   40篇
  2019年   71篇
  2018年   62篇
  2017年   62篇
  2016年   65篇
  2015年   82篇
  2014年   118篇
  2013年   137篇
  2012年   226篇
  2011年   225篇
  2010年   110篇
  2009年   94篇
  2008年   146篇
  2007年   188篇
  2006年   182篇
  2005年   180篇
  2004年   150篇
  2003年   150篇
  2002年   122篇
  2001年   6篇
  2000年   3篇
  1999年   4篇
  1998年   9篇
  1997年   4篇
  1996年   6篇
  1995年   8篇
  1994年   2篇
  1992年   1篇
  1991年   2篇
  1990年   5篇
  1988年   1篇
  1987年   1篇
  1981年   1篇
  1974年   1篇
  1972年   1篇
  1967年   1篇
  1925年   1篇
排序方式: 共有2710条查询结果,搜索用时 15 毫秒
31.

Background

L-asparaginase (L-asp) remains one of the key components of acute lymphoblastic leukemia therapy. Immune reactions to the drug are associated with its diminished activity. The aim of the study was to determine the level of IgM, IgG and IgE-class anti-L-asp antibodies during the induction and reinduction phases of acute lymphoblastic leukemia therapy and their influence on L-asp activity.

Methods

The study group comprised 65 patients treated for acute lymphoblastic leukemia in one pediatric oncology center. L-asp antibodies were assessed using ELISA at the end of the induction and reinduction phases. L-asp activity was assessed prior to each drug administration by colorimetry.

Results

At the end of the first exposure to L-asp antibodies were detected in 35 patients (54%). In the reinduction phase of the treatment anti-L-asp antibodies were found in 38/55 patients (69%). In the induction phase patients with inadequate L-asp activity had higher IgM concentrations (median 5.88 versus 2.81?μg/mL, p?=?0.03). In the reinduction phase IgG and IgM levels correlated inversely with L-asp activity. Patients with L-asp allergy had higher levels of IgG (median 61.6 versus 18.36 μg/mL, p?=?0.01), whereas higher IgE levels were noted in the group of patients with inadequate drug activity (median 0.91 versus 0.64 μg/mL, p?=?0.03).

Conclusions

Subsequent exposure to L-asp in the treatment of acute lymphoblastic leukemia was associated with the increase of anti-L-asp antibodies in all studied classes. However, the changes observed in specific classes of antibodies were not distinctive for L-asp hypersensitivity or inactivation, suggesting that the mechanism is more complex.  相似文献   
32.
33.
34.
ObjectivesThe role of pro-inflammatory cytokines in the course of chronic otitis media with effusion (COME) has been documented. However, there are fewer studies on the action of anti-inflammatory cytokines in the middle ear. We sought determine whether there is an association between COME and anti-inflammatory cytokines and whether there are any differences in the cytokine profile in COME children with and without atopy.MethodsEighty-four children were divided into 3 groups: 32 nonatopic children with COME (group NA), 31 atopic children with COME (group A), and 21 children without COME and without atopy (control group C). Specimens from the middle ear were collected and evaluated by enzyme-linked immunosorbent assay for the cytokines interleukin-1 receptor antagonist (IL-1Ra) and immunoregulatory IL-10.ResultsSignificantly higher IL-10 concentrations were found in both nonatopic and atopic children with COME compared to controls. No significant differences in IL-1Ra levels were found between atopic and nonatopic children with COME and the control group.ConclusionWe found no differences in the levels of IL-1Ra in atopic and nonatopic children with COME compared to controls. However, we found elevated IL-10 levels in the middle ear effusions from children with COME, with or without atopy. These elevated immunoregulatory cytokine levels suggest a role for new immunomodulatory treatments to prevent disease progression in COME, regardless of atopy.  相似文献   
35.
AIM: To investigate the indications and outcomes of liver transplantation for hepatic epithelioid hemangioendothelioma (HEHE).METHODS: Between 1989 and August 2013, in the Department of General, Transplant, and Liver Surgery, Medical University of Warsaw, 1306 orthotopic liver transplantations (OLTx) were performed, including 72 retransplantations. Unresectable HEHE was an indication for OLTx in 10 patients (0.8% of primary OLTx), the mean age of the patients was 40.5 ± 13.3 years (range 23-65 years), and the male-to-female ratio was 2:8. Kaplan-Meier survival analysis in HEHE, hepatocellular carcinoma (HCC), and other OLTx recipients groups was performed. The differences in mortality were compared using the χ2 test. A P-value < 0.05 indicated statistical significance.RESULTS: No concomitant liver disease was found in any patient. There was no neoadjuvant chemotherapy or radiotherapy. Liver function test results were normal in most of the patients. The levels of alpha-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 19-9 were normal. In immunohistochemical staining, the neoplastic cells were positive for factor VIII-related antigen, CD31, and CD34, which are endothelial cell markers, and negative for cytokeratin 19, cytokeratin 7, and HepPar-1. Nine patients were alive without tumor recurrence. One patient died 2 mo after OLTx due to septic complications. No morbidity was observed. Maximum follow-up was 11.4 years, with a minimum of 1 mo. The cumulative survival rate at the end of follow-up in HEHE patients was 87.5% compared with 54.3% in the HCC group and 76.3% in the other OLTx recipients group (χ2 test = 1.784, df = 2, P = 0.409).CONCLUSION: Unresectable HEHE, without extrahepatic metastases is an excellent indication for liver transplantation. Long-term survival is very good and much better than in HCC patients and the entire group of OLTx patients.  相似文献   
36.
Early non-haematological toxicity of high dose therapy (HDT) and autologous haematopoietic cell transplantation (autoHCT) can be more hazardous in older patients (pts) with comorbidities. The aim of the study was to analyze incidence and grade of the organ-related early complications up to 30 days post-transplant period in elderly lymphoma patients. Between January 2005 and November 2011, 44 consecutive lymphoma pts underwent HDT followed by autoHCT. Median age of pts was 62 years (range 60–67). Conditioning regimens were: BEAM(carmustine, etoposide, cytarabine, melphalan) in 16, melphalan 200 in 22, cytarabine, melphalan or cyclophosphamide – in 6 pts. 32% pts had comorbidities: in 71% cardiovascular. Early non-haematologic complications within 30 days after autoHCT were reported in 84% of pts. The most common events were gastrointestinal (77%): 55% pts had prolonged (more than 7 days) diarrhoea grade III—IV, nausea and vomiting occurred in 40% of pts, 50% of pts demonstrated mucositis (grade III—IV in 34% of pts). Neutropenic fever was reported in 59% of pts with sepsis in 1.9% of pts. Cardiac events occurred in 9% of pts. Median hospitalization was 21 days (range 16—45). One patient died from transplanted related toxicity. HDT resulted in high incidence of non-hematologic toxicity in elderly patients during early post-transplant period. The toxicity of this procedure is acceptable, with mortality rate of only 2% in the elderly transplanted patients. The most common toxicities were: neutropenic fever, gastrointestinal toxicity and cardiac complications  相似文献   
37.
38.
Background. The aim of this study was to evaluate gender differences in the long-term clinical outcomes and safety of patients treated with first- and second generation DES. Methods. The Katowice–Zabrze Registry included 1916 consecutive patients treated with either first or second generation DES. We evaluated major adverse cardiac and cerebrovascular events (MACCE) [composite of death, myocardial infarction (MI), stroke and target vessel revascularization (TVR)] at 12-month follow-up. Safety end point was bleeding complications and stent thrombosis. Results. Registry included [unstable angina (UA) 1500(78%), non-ST-segment elevation myocardial infarction (NSTEMI) 285 (15%), ST-segment elevation myocardial infarction/left bundle branch block (STEMI/LBBB) 131 (7%)]. There were 35.5% females and 64.5% males. Women were older and had higher prevalence of comorbidities. Males more often had multivessel disease and higher Syntax score when comparable to females. We did not observed difference in acute and subacute stent thrombosis in our data, however, females had more in-hospital bleeding complications. Univariable Cox regression analysis revealed that women had similar outcomes when compared to men in terms of a risk of death, MI, TVR, stroke and MACCE at 1-year follow-up. There were no differences between males and females in MACCE when first- and second generation DES were analyzed separately. Conclusion. Despite higher risk profile, women treated with DES have similar outcomes as males in 1-year follow-up. However there is, an increased risk of in-hospital bleedings in women.  相似文献   
39.
Inflammatory cascades induced by spinal cord injuries (SCI) are localized in the white matter, a recognized neural stem‐ and progenitor‐cell (NSPC) niche of the adult spinal cord. Chemokines, as integrators of these processes, might also be important determinants of this NSPC niche. CCL3/CCR1, CCL2/CCR2, and SDF‐1α/CXCR4 were analyzed in the ventrolateral white matter after force defined thoracic SCI: Immunoreactivity (IR) density levels were measured 2 d, 7 d, 14 d, and 42 d on cervical (C 5), thoracic (T 5), and lumbar (L 5) levels. On day post operation (DPO) 42, chemokine inductions were further evaluated by real‐time RT‐PCR and Western blot analyses. Cellular phenotypes were confirmed by double labeling with markers for major cell types and NSPCs (nestin, Musashi‐1, NG2, 3CB2, BLBP). Mitotic profiles were investigated in parallel by BrdU labeling. After lesion, chemokines were induced in the ventrolateral white matter on IR‐, mRNA‐, and protein‐level. IR was generally more pronounced after severe lesions, with soaring increases of CCL2/CCR2 and continuous elevations of CCL3/CCR1. SDF‐1α and CXCR4 IR induction was focused on thoracic levels. Chemokines/‐receptors were co‐expressed with astroglial, oligodendroglial markers, nestin, 3CB2 and BLBP by cells morphologically resembling radial glia on DPO 7 to DPO 42, and NG2 or Musashi‐1 on DPO 2 and 7. In the white matter BrdU positive cells were significantly elevated after lesion compared with sham controls on all investigated time points peaking in the early time course on thoracic level: Here, chemokines were co‐expressed by subsets of BrdU‐labeled cells. These findings suggest an important role of chemokines/‐receptors in the subpial white matter NSPC niche after SCI. © 2010 Wiley‐Liss, Inc.  相似文献   
40.
In order to learn the heterogeneity of the DNA of B. burgdorferi s.l. and the prevalence of co-infections of B. burgdorferi s.l. genospecies in the populations of I. ricinus, collected in north-western Poland, the nested PCR method was applied, a fragment of the fla gene being used as a marker. Basing on the prevalence data of B. burgdorferi s.l. DNA in I. ricinus ticks in 8 sampling sites during 1998-2001, it may be stated that a risk of contracting Lyme disease exists in forested areas of north-western Poland, the highest in relation to B. burgdorferi s.s. (76.3% infected ticks), lower by B. garinii (2% infected ticks), and minimal threat being posed by B. afzelii (0.3%). I. ricinus ticks collected in north-western Poland pose a risk of contracting double infection by B. burgdorferi s.l. genospecies, i.e. B. burgdorferi s.s. with B. garinii, and B. burgdorferi s.s. with B. afzelii. The north-western part of Poland represents an endemic area for B. burgdorferi s.l.  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