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   329篇
  免费   19篇
  国内免费   1篇
耳鼻咽喉   5篇
儿科学   4篇
妇产科学   1篇
基础医学   8篇
口腔科学   3篇
临床医学   34篇
内科学   47篇
皮肤病学   1篇
神经病学   103篇
特种医学   3篇
外科学   42篇
综合类   3篇
预防医学   7篇
眼科学   2篇
药学   26篇
中国医学   2篇
肿瘤学   58篇
  2023年   2篇
  2022年   1篇
  2021年   6篇
  2019年   2篇
  2018年   10篇
  2017年   2篇
  2016年   6篇
  2015年   14篇
  2014年   16篇
  2013年   14篇
  2012年   16篇
  2011年   22篇
  2010年   20篇
  2009年   10篇
  2008年   27篇
  2007年   21篇
  2006年   19篇
  2005年   19篇
  2004年   14篇
  2003年   19篇
  2002年   13篇
  2001年   5篇
  2000年   10篇
  1999年   4篇
  1998年   1篇
  1996年   2篇
  1994年   2篇
  1993年   2篇
  1992年   12篇
  1991年   11篇
  1990年   7篇
  1989年   6篇
  1988年   6篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1980年   1篇
排序方式: 共有349条查询结果,搜索用时 15 毫秒
41.
BACKGROUND: Electromagnetic navigation bronchoscopy (ENB) with biopsy under fluoroscopic guidance has enhanced the yield of flexible bronchoscopy in the diagnosis of peripheral lung lesions. However, the accuracy of ENB navigation suggests that the addition of fluoroscopy is redundant. OBJECTIVES: Data were prospectively collected to determine the yield of ENB without fluoroscopy in the diagnosis of peripheral lung lesions. METHOD: ENB was performed via flexible bronchoscopy (superDimension/Bronchus system; superDimension Inc; Plymouth, MN). Biopsy specimens were obtained through the extended working channel after navigation. Fluoroscopy was not utilized, but post-transbronchial biopsy chest radiographs were obtained to exclude pneumothorax. The primary end point was diagnostic yield, and the secondary end points were navigation accuracy, procedure duration, and safety. Analysis by lobar distribution was also performed to assess performance in different lobes of the lung. RESULTS: Ninety-two peripheral lung lesions were biopsied in the 89 subjects. The diagnostic yield of ENB was 67%, which was independent of lesion size. Total procedure time ranged from 16.3 to 45.0 min (mean [+/- SD] procedure time, 26.9 +/- 6.5 min). The mean navigation error was 9 +/- 6 mm (range, 1 to 31 mm). There were two incidences of pneumothorax for which no intervention was required. When analyzed by lobar distribution, there was a trend toward a higher ENB yield in diagnosing lesions in the right middle lobe (88%). CONCLUSIONS: ENB can be used as a stand-alone bronchoscopic technique without compromising diagnostic yield or increasing the risk of pneumothorax. This may result in sizable timesaving and avoids radiation exposure.  相似文献   
42.
Disruptive behavior as a predictor in Alzheimer disease   总被引:1,自引:0,他引:1  
BACKGROUND: Disruptive behavior is common in Alzheimer disease (AD). There are conflicting reports regarding its ability to predict cognitive decline, functional decline, institutionalization, and mortality. OBJECTIVE: To examine whether the presence of disruptive behavior has predictive value for important outcomes in AD. DESIGN: Using the Columbia University Scale for Psychopathology in Alzheimer Disease (administered every 6 months, for a total of 3438 visit-assessments and an average of 6.9 per patient), the presence of disruptive behavior (wandering, verbal outbursts, physical threats/violence, agitation/restlessness, and sundowning) was extracted and examined as a time-dependent predictor in Cox models. The models controlled for the recruitment cohort, recruitment center, informant status, sex, age, education, a comorbidity index, baseline cognitive and functional performance, and neuroleptic use. SETTING: Five university-based AD centers in the United States and Europe (Predictors Study). PARTICIPANTS: Four hundred ninety-seven patients with early-stage AD (mean Folstein Mini-Mental State Examination score, 20 of 30 at entry) who were recruited and who underwent semiannual follow-up for as long as 14 (mean, 4.4) years. MAIN OUTCOME MEASURES: Cognitive (Columbia Mini-Mental State Examination score, < or = 20 of 57 [approximate Folstein Mini-Mental State Examination score, < or = 10 of 30]) and functional (Blessed Dementia Rating Scale score, parts I and II, > or = 10) ratings, institutionalization equivalent index, and death. RESULTS: At least 1 disruptive behavioral symptom was noted in 48% of patients at baseline and in 83% at any evaluation. Their presence was associated with increased risks of cognitive decline (hazard ratio 1.45 [95% confidence interval (CI), 1.03-2.03]), functional decline (1.66 [95% CI, 1.17-2.36]), and institutionalization (1.47 [95% CI, 1.10-1.97]). Sundowning was associated with faster cognitive decline, wandering with faster functional decline and institutionalization, and agitation/restlessness with faster cognitive and functional decline. There was no association between disruptive behavior and mortality (hazard ratio, 0.94 [95% CI, 0.71-1.25]). CONCLUSION: Disruptive behavior is very common in AD and predicts cognitive decline, functional decline, and institutionalization but not mortality.  相似文献   
43.
44.
OBJECTIVE: To assess combined antidepressant and cognitive enhancer treatment in elderly patients presenting with depression plus cognitive impairment. METHODS: Twenty-three elderly (>50 years old) depressed, cognitively impaired (DEP-CI) patients participated in a pilot study. We evaluated whether, after 8 weeks of open antidepressant treatment, donepezil HCl (Aricept) would afford added cognitive benefit compared to placebo in a randomized 12-week trial. A subsample continued in an 8-month extension phase of open treatment with donepezil. Neuropsychological testing (NPT) was performed and antidepressant response monitored at baseline and the 8, 20, and 52-week time points. RESULTS: At 8-weeks, the antidepressant response rate was 61% (14/23). Improvement in SRT immediate recall (SRT-IR; e.g. episodic verbal memory) was observed in responders compared to non-responders. During the 12-week, placebo-controlled, donepezil add-on trial, patients on donepezil showed further improvement in SRT-IR versus patients on placebo. In the open extension phase, patients who continued open donepezil treatment (n = 6) maintained improvement in memory and tended to show an advantage over patients who never received donepezil and were evaluated at the 52-week time point (n = 6). There were no observed significant donepezil effects on non-memory cognitive domains. CONCLUSION: These preliminary findings suggest that addition of a cholinesterase inhibitor (AChEI) following antidepressant medication treatment in elderly Dep-CI patients may improve cognition, and support the need for a confirmatory, larger randomized placebo-controlled trial.  相似文献   
45.
Subtraction hybridization applied to a 'differentiation therapy' model of cancer employing human melanoma cells resulted in the cloning of melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24). Initial studies confirm an inverse correlation between mda-7 expression and melanoma development and progression. Forced expression of mda-7 by means of a plasmid or via a replication incompetent adenovirus (Ad.mda-7) promotes growth suppression and induces apoptosis in a broad array of human cancers. In contrast, mda-7 does not induce growth suppressive or toxic effects in normal cells. Based on structure (containing an IL-10 signature motif), secretion by cells (including subsets of T-cells) and location on chromosome 1q (in an area containing IL-10-family genes), mda-7 has now been renamed mda-7/IL-24. Studies by several laboratories have uncovered many of mda-7/IL-24's unique properties, including cancer-specific apoptosis-induction, cell cycle regulation, an ability to inhibit angiogenesis, potent 'bystander antitumor activity' and a capacity to enhance the sensitivity of tumor cells to radiation, chemotherapy and monoclonal antibody therapy. Moreover, based on its profound cancer tropism, substantiated by in vivo human xenograft studies in nude mice, mda-7/IL-24 (administered as Ad.mda-7) was evaluated in a phase I clinical trial in patients with melanomas and solid cancers. These studies document that mda-7/IL-24 is well tolerated and demonstrates evidence of significant clinical activity. In these contexts, mda-7/IL-24 represents a unique cytokine gene with potential for therapy of human cancers. The present review focuses on three unique properties of mda-7/IL-24, namely its potent 'bystander antitumor activity', ability to sensitize tumor cells to radiation, and its antiangiogenesis properties. Additionally, an overview of the phase I clinical trial is provided. These studies affirm that mda-7/IL-24 has promise for the management of diverse cancers.  相似文献   
46.
The authors examined three indicators of health-related quality of life in people with advanced Alzheimer's disease ([AD]; N=150): confinement to home, null activity, and null positive affect, as reported by patient proxies. Dementia severity predicted time-to-onset for all three disease milestones in models that controlled for sociodemographic indicators, nursing home status, and death in the follow-up period. Patients whose dementia worsened over follow-up were more likely to reach each milestone. These outcomes represent key milestones in the care of patients; they are sensitive to disease progression, and they are likely to be useful for studying treatment in advanced AD.  相似文献   
47.
Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) is a novel cytokine displaying selective apoptosis-inducing activity in transformed cells without harming normal cells. The present studies focused on defining the mechanism(s) by which a GST-MDA-7 fusion protein inhibits cell survival of primary human glioma cells in vitro. GST-MDA-7 killed glioma cells with diverse genetic characteristics that correlated with inactivation of ERK1/2 and activation of JNK1-3. Activation of JNK1-3 was dependent on protein kinase R-like endoplasmic reticulum kinase (PERK), and GST-MDA-7 lethality was suppressed in PERK-/- cells. JNK1-3 signaling activated BAX, whereas inhibition of JNK1-3, deletion of BAX, or expression of dominant-negative caspase-9 suppressed lethality. GST-MDA-7 also promoted a PERK-, JNK-, and cathepsin B-dependent cleavage of BID; loss of BID function promoted survival. GST-MDA-7 suppressed BAD and BIM phosphorylation and heat shock protein 70 (HSP70) expression. GST-MDA-7 caused PERK-dependent vacuolization of LC3-expressing endosomes whose formation was suppressed by incubation with 3-methyladenine, expression of HSP70 or BiP/GRP78, or knockdown of ATG5 or Beclin-1 expression but not by inhibition of the JNK1-3 pathway. Knockdown of ATG5 or Beclin-1 expression or overexpression of HSP70 reduced GST-MDA-7 lethality. Our data show that GST-MDA-7 induces an endoplasmic reticulum stress response that is causal in the activation of multiple proapoptotic pathways, which converge on the mitochondrion and highlight the complexity of signaling pathways altered by mda-7/IL-24 in glioma cells that ultimately culminate in decreased tumor cell survival.  相似文献   
48.
We report the use of high-performance liquid chromatography (HPLC) to identify the cause of prolonged neuromuscular blockade in a child who had received 2 mg.kg-1 of succinylcholine. Upon analysis by HPLC the syringe was found to contain succinylcholine (10 mg.ml-1) and also atracurium (5 mg.ml-1), so that a diagnosis was established. In situations where medication errors are suspected, we recommend saving syringe contents for analysis for confirmation of the agent.  相似文献   
49.
50.
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