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   2326篇
  免费   81篇
  国内免费   49篇
耳鼻咽喉   7篇
儿科学   57篇
妇产科学   40篇
基础医学   304篇
口腔科学   37篇
临床医学   228篇
内科学   569篇
皮肤病学   48篇
神经病学   179篇
特种医学   54篇
外国民族医学   1篇
外科学   488篇
综合类   9篇
预防医学   74篇
眼科学   24篇
药学   109篇
中国医学   2篇
肿瘤学   226篇
  2023年   6篇
  2022年   11篇
  2021年   31篇
  2020年   12篇
  2019年   14篇
  2018年   35篇
  2017年   18篇
  2016年   23篇
  2015年   32篇
  2014年   41篇
  2013年   78篇
  2012年   149篇
  2011年   150篇
  2010年   100篇
  2009年   105篇
  2008年   177篇
  2007年   211篇
  2006年   168篇
  2005年   168篇
  2004年   176篇
  2003年   157篇
  2002年   140篇
  2001年   25篇
  2000年   18篇
  1999年   21篇
  1998年   45篇
  1997年   44篇
  1996年   24篇
  1995年   22篇
  1994年   27篇
  1993年   18篇
  1992年   14篇
  1991年   17篇
  1990年   13篇
  1989年   13篇
  1988年   14篇
  1987年   11篇
  1986年   9篇
  1985年   7篇
  1984年   9篇
  1983年   8篇
  1982年   10篇
  1981年   11篇
  1980年   6篇
  1979年   10篇
  1978年   9篇
  1977年   6篇
  1976年   7篇
  1975年   7篇
  1970年   9篇
排序方式: 共有2456条查询结果,搜索用时 109 毫秒
1.

Background

In a pooled analysis of the phase 3 Controlled Myelofibrosis Study With Oral JAK Inhibitor Treatment I (COMFORT-I) and COMFORT-II clinical trials, adult patients with intermediate-2 or high-risk myelofibrosis who received oral ruxolitinib at randomization or after crossover from placebo or best available therapy (BAT) had improved overall survival (OS).

Methods

This post hoc analysis of pooled COMFORT data examined relevant disease outcomes based on the disease duration (≤12 or >12 months from diagnosis) before ruxolitinib initiation.

Results

The analysis included 525 patients (ruxolitinib: ≤12 months, n = 84; >12 months, n = 216; placebo/BAT: ≤12 months, n = 66; >12 months, n = 159); the median age was 65.0–70.0 years. Fewer thrombocytopenia and anemia events were observed among patients who initiated ruxolitinib treatment earlier. At Weeks 24 and 48, the spleen volume response (SVR) was higher for patients who initiated ruxolitinib earlier (47.6% vs. 32.9% at Week 24, p = .0610; 44.0% vs. 26.9% at Week 48, p = .0149). In a multivariable analysis of factors associated with spleen volume reduction, a logistic regression model that controlled for confounding factors found that a significantly greater binary reduction was observed among patients with shorter versus longer disease duration (p = .022). At Week 240, OS was significantly improved among patients who initiated ruxolitinib earlier (63% [95% CI, 51%‒73%] vs. 57% [95% CI, 49%‒64%]; hazard ratio, 1.53; 95% CI, 1.01‒2.31; p = .0430). Regardless of disease duration, a longer OS was observed for patients who received ruxolitinib versus those who received placebo/BAT.

Conclusions

These findings suggest that earlier ruxolitinib initiation for adult patients with intermediate-2 and high-risk myelofibrosis may improve clinical outcomes, including fewer cytopenia events, durable SVR, and prolonged OS.

Plain Language Summary

  • Patients with myelofibrosis, a bone marrow cancer, often do not live as long as the general population. These patients may also have an enlarged spleen and difficult symptoms such as fatigue.
  • Two large clinical trials showed that patients treated with the drug ruxolitinib lived longer and had improved symptoms compared to those treated with placebo or other standard treatments.
  • Here it was examined whether starting treatment with ruxolitinib earlier (i.e., within a year of diagnosis) provided benefits versus delaying treatment.
  • Patients who received ruxolitinib within a year of diagnosis lived longer and experienced fewer disease symptoms than those whose treatment was delayed.
  相似文献   
2.

Introduction  

Positive end-expiratory pressure (PEEP)-induced lung derecruitment can be assessed by a pressure–volume (P–V) curve method or by lung computed tomography (CT). However, only the first method can be used at the bedside. The aim of the study was to compare both methods for assessing alveolar derecruitment after the removal of PEEP in patients with acute lung injury or acute respiratory distress syndrome.  相似文献   
3.
Background: Pulmonary concentrations of aminoglycosides administered intravenously are usually low in the infected lung parenchyma. Nebulization represents an alternative to increase pulmonary concentrations, although the obstruction of bronchioles by purulent plugs may impair lung deposition by decreasing lung aeration.

Methods: An experimental bronchopneumonia was induced in anesthetized piglets by inoculating lower lobes with a suspension of 106 cfu/ml Escherichia coli. After 24 h of mechanical ventilation, 7 animals received two intravenous injections of 15 mg/kg amikacin, and 11 animals received two nebulizations of 40 mg/kg amikacin at 24-h intervals. One hour following the second administration, animals were killed, and multiple lung specimens were sampled for assessing amikacin pulmonary concentrations and quantifying lung aeration on histologic sections.

Results: Thirty-eight percent of the nebulized amikacin (15 mg/kg) reached the tracheobronchial tree. Amikacin pulmonary concentrations were always higher after nebulization than after intravenous administration, decreased with the extension of parenchymal infection, and were significantly influenced by lung aeration: 197 +/- 165 versus 6 +/- 5 [mu]g/g in lung segments with focal bronchopneumonia (P = 0.03), 40 +/- 62 versus 5 +/- 3 [mu]g/g in lung segments with confluent bronchopneumonia (P = 0.001), 18 +/- 7 versus 7 +/- 4 [mu]g/g in lung segments with lung aeration of 30% or less, and 65 +/- 9 versus 2 +/- 3 [mu]g/g in lung segments with lung aeration of 50% or more.  相似文献   

4.
Background: Malposition of percutaneously inserted chest tubes is considered as a rare complication in critically ill patients. Its incidence, however, remains uncertain. The aims of the study were to assess the true incidence of chest tube malposition in critically ill patients and to identify predicting factors.

Methods: The authors prospectively studied 122 chest tubes percutaneously inserted in 75 consecutive critically ill patients. For clinical reasons independent of the study, thoracic computed tomography scanning was performed in 63 patients, allowing direct visualization of 106 chest tubes. Based on these findings, chest tube position was classified as intrapleural, intrafissural, or intraparenchymal. Factors predicting chest tube malposition were analyzed by univariate and multivariate analysis.

Results: The mean delay between chest tube placement and thoracic scan was 3.5 +/- 2.9 days. Twenty-two chest tubes were diagnosed as being intrafissural (21%), and 10 were diagnosed as being intraparenchymal (9%). The only predicting factor associated with the risk of malposition was the use of a trocar for the percutaneous insertion of the chest tube (P = 0.032).  相似文献   

5.
6.
The aim of this study was to detect salvageable peri-infarction myocardium by MRI in rats after infarction, using with a double contrast agent (CA) protocol at 7 Tesla. Intravascular superparamagnetic iron oxide (SPIO) nanoparticles and an extracellular paramagnetic CA (Gd-DOTA) were used to characterize the peri-infarction zone, which may recover function after reperfusion occurs. Infarcted areas measured from T1-weighted (T1-w) images post Gd-DOTA administration were overestimated compared to histological TTC staining (52% +/- 3% of LV surface area vs. 40% +/- 3%, P=0.03) or to T2-w images post SPIO administration (41% +/- 4%, P=0.04), whereas areas measured from T2-w images post SPIO administration were not significantly different from those measured histologically (P=0.7). Viable and nonviable myocardium portions of ischemically injured myocardium were enhanced after diffusive Gd-DOTA injection. The subsequent injection of vascular SPIO nanoparticles enables the discrimination of viable peri-infarction regions by specifically altering the signal of the still-vascularized myocardium.  相似文献   
7.
Transplant atherosclerotic coronary disease remains the leading cause of death in heart transplant recipients. We report the first case of coronary stent implantation in a heart graft for epicardial focal stenosis. Due to the lower rate of restenosis after stenting in the native coronary artery, we suggest that coronary stenting be considered an acceptable, first intention therapeutic option instead of angioplasty alone whenever possible.  相似文献   
8.
9.
10.
A glycolipid (J001X) isolated from the membrane proteoglycans of a non-pathogenic strain of Klebsiella pneumoniae was developed to bind selectively to macrophages. A scintigraphic technique could thus be developed and applied to an experimental model of lung berylliosis. Six baboons were injected intratracheally with a beryllium metal suspension. Three to 24 months later, they were submitted to both an anatomical and a functional respiratory evaluation. Two baboons were explored at the early stage of alveolitis and four baboons at a more advanced stage characterised by a granulomatous disorder. Scintigraphy was performed using J001X labelled with 99mtechnetium administered as an aerosol. In the six baboons, conventional imaging techniques (chest x ray film, computed tomography scan, gallium scintigraphy), failed to show either any lung abnormality or mediastinal lymph nodes consistent with beryllium disease. In the two recently contaminated baboons, J001X scintigraphy showed a well defined parenchymal fixation facing the contaminated lobe. In the four baboons who were at a more advanced stage of berylliosis, J001X fixation was always focused paratracheally without any significant involvement of the lung parenchyma. The subcarinal and laterotracheal lymph nodes seen at necropsy corresponded to J001X scintigraphic fixations. In conclusion, when compared with conventional techniques such as chest x ray film, computed tomography scan, magnetic resonance imaging, and gallium scintigraphy, J001X scintigraphy has proved its ability to detect occult lesions in experimental berylliosis in baboons. By comparison with gallium scintigraphy, scintigraphy with J001X appears to have superior sensitivity and can be performed in four hours.  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