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   2189篇
  免费   123篇
  国内免费   17篇
耳鼻咽喉   75篇
儿科学   71篇
妇产科学   20篇
基础医学   173篇
口腔科学   21篇
临床医学   257篇
内科学   703篇
皮肤病学   40篇
神经病学   122篇
特种医学   166篇
外科学   211篇
综合类   24篇
一般理论   1篇
预防医学   116篇
眼科学   17篇
药学   131篇
中国医学   1篇
肿瘤学   180篇
  2021年   27篇
  2020年   10篇
  2019年   35篇
  2018年   30篇
  2017年   15篇
  2016年   27篇
  2015年   30篇
  2014年   42篇
  2013年   54篇
  2012年   69篇
  2011年   64篇
  2010年   58篇
  2009年   41篇
  2008年   88篇
  2007年   88篇
  2006年   88篇
  2005年   100篇
  2004年   73篇
  2003年   74篇
  2002年   82篇
  2001年   82篇
  2000年   68篇
  1999年   68篇
  1998年   44篇
  1997年   48篇
  1996年   36篇
  1995年   34篇
  1994年   33篇
  1993年   32篇
  1992年   55篇
  1991年   70篇
  1990年   64篇
  1989年   52篇
  1988年   43篇
  1987年   45篇
  1986年   59篇
  1985年   49篇
  1984年   47篇
  1983年   22篇
  1982年   35篇
  1981年   21篇
  1980年   20篇
  1979年   31篇
  1978年   25篇
  1977年   25篇
  1976年   18篇
  1975年   26篇
  1974年   16篇
  1973年   11篇
  1972年   12篇
排序方式: 共有2329条查询结果,搜索用时 15 毫秒
51.
52.
53.
PURPOSE: Point mutations within the ABL kinase domain of the BCR-ABL gene have been associated with clinical resistance to imatinib mesylate in chronic myeloid leukemia (CML) patients. To shed further light on the frequency, distribution, and prognostic significance of ABL mutations, we retrospectively analyzed a homogeneous cohort of late chronic phase CML patients who showed primary cytogenetic resistance to imatinib. PATIENTS AND METHODS: Using denaturing high-performance liquid chromatography (D-HPLC) and sequencing, we screened for ABL mutations in a total of 178 bone marrow and/or peripheral blood samples from 40 late chronic phase CML patients homogeneously treated with imatinib 400 mg/d, who did not reach a major cytogenetic response at 12 months. RESULTS: Mutations were found in 19 of 40 patients (48%). Mutations were already detectable by D-HPLC at a median of 3 months from the onset of therapy. The presence of a missense mutation was significantly associated with a greater likelihood of subsequent progression to accelerated phase/blast crisis (P = .0002) and shorter survival (P = .001). Patients carrying mutations falling within the P-loop seemed to have a particularly poor outcome in terms of time to progression (P = .032) and survival (P = .045). CONCLUSION: Our results show that, irrespective of the hematologic response, monitoring for emerging mutations in the first months of therapy may play a role in detecting patients with worse prognosis, for whom a revision of the therapeutic strategy should be considered.  相似文献   
54.
PURPOSE: To define the toxicities, pharmacodynamics, and clinical activity of the proteasome inhibitor, PS-341 (bortezomib), in patients with advanced malignancies. PATIENTS AND METHODS: Twenty-eight patients (14 male and 14 female) received PS-341 twice weekly for 4 of 6 weeks (schedule I). Because toxicity necessitated dose omissions on this schedule, 16 additional patients (12 male and 4 female) received PS-341 twice weekly for 2 of every 3 weeks (schedule II). A total of 73 courses of treatment was given (median, 2; range, 1-4). Inhibition of 20S proteasome activity in peripheral blood mononuclear cells (PBMC) and accumulation of proteasome-targeted polypeptides in tumor tissue were evaluated as pharmacodynamic markers of PS-341 activity. RESULTS: The most common toxicity was thrombocytopenia, which was dose limiting at 1.7 mg/m2 (schedule I) and 1.6 mg/m2 (schedule II), respectively. Sensory neuropathy was dose-limiting in a patient in schedule I. Grade > or =3 toxicities for schedule I were constipation, fatigue, myalgia, and sensory neuropathy. Grade > or =3 toxicities for schedule II were dehydration resulting from diarrhea, nausea and vomiting, fatigue, hypoglycemia, and hypotension. The maximum tolerated dose was 1.5 mg/m2 for both schedules. Reversible dose-dependent decreases in 20S proteasome activity in PBMCs were observed, with 36% inhibition at 0.5 mg/m2, 52% at 0.9 mg/m2, and 75% at 1.25 mg/m2. Accumulation of proteasome-targeted polypeptides was detected in tumor samples after treatment with PS-341. A patient with multiple myeloma had a partial response. CONCLUSION: PS-341 given 1.5 mg/m2 twice weekly for 2 of every 3 weeks is well tolerated and should be further studied.  相似文献   
55.
At present, a variety of agents targeting tumor angiogenesis are under clinical investigation as new therapies for patients with cancer. Overexpression of the alpha(v)beta(3) integrin on tumor vasculature has been associated with an aggressive phenotype of several solid tumor types. Murine models have shown that antibodies targeting the alpha(v)beta(3) integrin can affect tumor vasculature and block tumor formation and metastasis. These findings suggest that antibodies directed at alpha(v)beta(3) could be investigated in the treatment of human malignancies. The current phase I dose escalation study evaluated the safety of MEDI-522, a monoclonal antibody specific for the alpha(v)beta(3) integrin, in patients with advanced malignancies. Twenty-five patients with a variety of metastatic solid tumors were treated with MEDI-522 on a weekly basis with doses ranging from 2 to 10 mg/kg/wk. Adverse events were assessed weekly; pharmacokinetic studies were done; and radiographic staging was done every 8 weeks. In addition, dynamic computed tomography imaging was done at baseline and at 8 weeks in patients with suitable target lesions amenable to analysis, to potentially identify the effect of MEDI-522 on tumor perfusion. Treatment was well tolerated, and a maximum tolerated dose was not identified by traditional dose-limiting toxicities. The major adverse events observed were grade 1 and 2 infusion-related reactions (fever, rigors, flushing, injection site reactions, and tachycardia), low-grade constitutional and gastrointestinal symptoms (fatigue, myalgias, and nausea), and asymptomatic hypophosphatemia. Dynamic computed tomography imaging suggested a possible effect on tumor perfusion with an increase in contrast mean transit time from baseline to the 8-week evaluation with increasing doses of MEDI-522. No complete or partial responses were observed. Three patients with metastatic renal cell cancer experienced prolonged stable disease (34 weeks, >1 and >2 years) on treatment. With this weekly schedule of administration, and in the doses studied, MEDI-522 seems to be without significant toxicity, may have effects on tumor perfusion, and may have clinical activity in renal cell cancer. These findings suggest the MEDI-522 could be further investigated as an antiangiogenic agent for the treatment of cancer.  相似文献   
56.
PURPOSE: To investigate variations of circulating serum levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha), and interleukin-10 (IL-10) during three-dimensional conformal radiation therapy (3D-CRT) in patients with non-small-cell lung cancer and correlate these variations with the occurrence of radiation pneumonitis. PATIENTS AND METHODS: Ninety-six patients receiving 3D-CRT for stage I to III disease were evaluated prospectively. Circulating cytokine levels were determined before, every 2 weeks during, and at the end of treatment. Radiation pneumonitis was evaluated prospectively between 6 and 8 weeks after 3D-CRT. The predictive value of clinical, dosimetric, and biologic (cytokine levels) factors was evaluated both in univariate and multivariate analyses. RESULTS: Forty patients (44%) experienced score 1 or more radiation pneumonitis. No association was found between baseline cytokine levels and the risk of radiation pneumonitis. In the whole population, mean levels of TNFalpha, IL-6, and IL-10 remained stable during radiotherapy. IL-6 levels were significantly higher (P = .047) during 3D-CRT in patients with radiation pneumonitis. In the multivariate analysis, covariations of IL-6 and IL-10 levels during the first 2 weeks of 3D-CRT were evidenced as independently predictive of radiation pneumonitis in this series (P = .011). CONCLUSION: Early variations of circulating IL-6 and IL-10 levels during 3D-CRT are significantly associated with the risk of radiation pneumonitis. Variations of circulating IL-6 and IL-10 levels during 3D-CRT may serve as independent predictive factors for this complication.  相似文献   
57.
58.
59.

Introduction

Pirfenidone was the first antifibrotic drug approved in Argentina for idiopathic pulmonary fibrosis (IPF). Outcomes in real life may differ from the results of clinical trials. The primary endpoint was to study the tolerance of pirfenidone in real life. Secondary endpoints were to analyze effectiveness and reasons for discontinuation.

Materials and methods

Retrospective observational study conducted in four specialized centers in Argentina. We analyzed the medical records of patients with IPF who received pirfenidone between June 2013 and September 2016. Adverse events (AE) and the variables that could influence these results were analyzed. Forced vital capacity (FVC%) parameters were also compared between the pre-pirfenidone and post-pirfenidone periods.

Results

Fifty patients were included, 38 (76%) men, with mean age (SD) 67.8 (8.36) years. Mean (SD) exposure to pirfenidone was 645.68 (428.19) days, with a mean daily dose (SD) of 2064.56 mg (301.49). Nineteen AEs in 15 patients (30%) were reported: nausea (14%), asthenia (10%) and skin rash (8%). A total of 18 patients (36%) interrupted treatment, only 1 definitively. The most frequent reason for discontinuation was failure of suppliers to provide the drug (9 subjects; 18%). We compared the evolution of FVC% between the pre-pirfenidone and post-pirfenidone periods, and found a mean (SD) FVC% decline of 4.03% (7.63) pre-pirfenidone and 2.64% (7.1) post-pirfenidone (P=.534).

Conclusions

In our study, pirfenidone was well tolerated and associated with a reduction in FVC decline, although without reaching statistical significance.  相似文献   
60.
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