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   14900篇
  免费   841篇
  国内免费   214篇
耳鼻咽喉   119篇
儿科学   702篇
妇产科学   95篇
基础医学   1252篇
口腔科学   405篇
临床医学   3370篇
内科学   2319篇
皮肤病学   44篇
神经病学   352篇
特种医学   425篇
外国民族医学   3篇
外科学   2255篇
综合类   2508篇
预防医学   834篇
眼科学   24篇
药学   999篇
  10篇
中国医学   172篇
肿瘤学   67篇
  2024年   8篇
  2023年   231篇
  2022年   391篇
  2021年   576篇
  2020年   564篇
  2019年   451篇
  2018年   497篇
  2017年   492篇
  2016年   554篇
  2015年   492篇
  2014年   1063篇
  2013年   979篇
  2012年   935篇
  2011年   1040篇
  2010年   795篇
  2009年   787篇
  2008年   736篇
  2007年   750篇
  2006年   665篇
  2005年   609篇
  2004年   469篇
  2003年   366篇
  2002年   274篇
  2001年   250篇
  2000年   197篇
  1999年   193篇
  1998年   142篇
  1997年   144篇
  1996年   153篇
  1995年   151篇
  1994年   117篇
  1993年   89篇
  1992年   98篇
  1991年   65篇
  1990年   94篇
  1989年   86篇
  1988年   63篇
  1987年   64篇
  1986年   49篇
  1985年   50篇
  1984年   46篇
  1983年   23篇
  1982年   28篇
  1981年   16篇
  1980年   31篇
  1979年   14篇
  1978年   18篇
  1977年   17篇
  1972年   6篇
  1971年   6篇
排序方式: 共有10000条查询结果,搜索用时 233 毫秒
61.
Atypical EEG patterns not consistent with standard sleep staging criteria have been observed in medical intensive care unit (ICU) patients. Our aim was to examine the relationship between sleep architecture and sedation in critically ill mechanically ventilated patients pre‐ and post‐extubation. We performed a prospective observational repeated measures study where 50 mechanically ventilated patients with 31 paired analyses were examined at an academic medical centre. The sleep efficiency was 58.3 ± 25.4% for intubated patients and 45.6 ± 25.4% for extubated patients (p = .02). Intubated patients spent 76.33 ± 3.34% of time in non‐rapid eye movement (NREM) sleep compared to 64.66 ± 4.06% of time for extubated patients (p = .02). REM sleep constituted 1.36 ± 0.67% of total sleep time in intubated patients and 2.06 ± 1.09% in extubated patients (p = .58). Relative sleep atypia was higher in intubated patients compared to extubated patients (3.38 ± 0.87 versus 2.79 ± 0.42; p < .001). Eleven patients were sedated with propofol only, 18 patients with fentanyl only, 11 patients with fentanyl and propofol, and 10 patients had no sedation. The mean sleep times on “propofol”, “fentanyl”, “propofol and fentanyl,” and “no sedation” were 6.54 ± 0.64, 4.88 ± 0.75, 6.20 ± 0.75 and 4.02 ± 0.62 hr, respectively. The sigma/alpha values for patients on “propofol”, “fentanyl”, “propofol and fentanyl” and “no sedation” were 0.69 ± 0.04, 0.54 ± 0.01, 0.62 ± 0.02 and 0.57 ± 0.02, respectively. Sedated patients on mechanical ventilation had higher sleep efficiency and more atypia compared to the same patients following extubation. Propofol was associated with higher sleep duration and less disrupted sleep architecture compared to fentanyl, propofol and fentanyl, or no sedation.  相似文献   
62.
There has been a significant increase in the past few decades in the number of children receiving noninvasive positive airway pressure (PAP) therapy at home. At present, PAP therapy can be successfully used in children of all ages, for a variety of indications. Data acquired from PAP devices is clinically useful, providing objective information regarding adherence, leak, and efficacy of PAP therapy. However, guidelines outlining a standardized approach to interpretation of PAP device data in pediatrics is currently lacking. Given the rapidly expanding use of PAP therapy in pediatric practice, we aim to provide an overview of the interpretation of data reports, otherwise called “data downloads,” from PAP devices and illustrate how they can be used to guide clinical care.  相似文献   
63.
64.
65.
PurposeTo overcome the limitations of traditional mechanical thrombectomy (MT), including catheter aspiration and stent retrievers, such as thrombus fragmentation or migration, we designed hybrid MT using an intermediate aspiration catheter and a Trevo stent simultaneously. We retrospectively compared hybrid MT with the traditional MT.MethodsFrom January 2017 to January 2019, we performed MT on 91 occlusions, including internal carotid artery bifurcation (n = 17), M1 segment (n = 53) and M2 segment (n = 21), using hybrid MT (n = 42) and traditional MT (n = 49).ResultsHybrid MT had a shorter procedure time (52.4 ± 22.0 vs. 73.0 ± 36.2 min, p = 0.002) and fewer attempts (1.50 ± 0.86 vs. 1.92 ± 1.10 times, p = 0.049) than traditional MT did. Hybrid MT achieved more good clinical outcome (3-month modified Rankin Scale score, 2 or less) and better successful recanalization (Thrombolysis In Cerebral Infarction grade, 2b or 3) than traditional MT did, but the difference was not significant (61.9% vs. 55.1%, p = 0.531, 92.9% vs. 87.8%, p = 0.498). Hybrid MT showed a higher first pass successful recanalization rate than traditional MT did (69.0% vs. 40.8%, p = 0.011). Multivariable logistic regression analysis demonstrated that first pass successful recanalization is related to the M1 segment rather than other segments (adjusted odds ratio (OR); 3.277, confidence interval (CI); 1.227–8.749, p = 0.018) and hybrid MT rather than traditional MT (adjusted OR; 4.995, CI; 1.725–14.460, p = 0.003).ConclusionsHybrid MT can be used as a first-line MT modality, particularly in M1 occlusion, based on our high first pass successful recanalization results.  相似文献   
66.
BackgroundAlthough tirofiban therapy is considered a potentially effective treatment to reduce the incidence of thrombotic complications in patients receiving endovascular treatment (EVT), the safety and efficacy of tirofiban remain controversial. Our objective was to investigate the efficacy and safety of EVT plus tirofiban therapy in patients with emergent large artery occlusion.MethodsRelevant articles from randomized controlled trials (RCTs) or observational studies that compared treatment with tirofiban to treatment without tirofiban in patients undergoing EVT were retrieved from the PubMed and Embase databases. We calculated odds ratios (ORs) with corresponding 95% confidence intervals (CIs) for the safety and efficacy outcomes based on a random effects model.ResultsTwelve studies including 2533 patients were identified for the analysis. Overall, the risk of fatal intracranial haemorrhage (ICH) was higher for the treatment with tirofiban group than for the treatment without tirofiban group in patients with large artery occlusion who underwent EVT (p = 0.002), whereas the risk of any ICH, symptomatic ICH, parenchymal haematoma type 2, in-hospital mortality and 3-month mortality did not differ significantly (p > 0.05). No significant differences in reocclusion rate, recanalization rate or excellent functional outcome were found between the patients treated with or without tirofiban, but significantly favourable functional outcome at 3 months occurred in the tirofiban group (p = 0.017).ConclusionsTirofiban administration in patients receiving EVT significantly improved 3-month favourable functional outcomes, whereas an increased risk of fatal ICH was also observed. Further rigorous trials are needed to verify the safety of tirofiban.  相似文献   
67.
Acute ischemic stroke (AIS) is a leading cause of mortality and morbidity in the world. Patients are usually treated with endovascular methods and access is often gained trans-femoral or trans-radial. In patients with difficult anatomy, in rare cases the approach must be done trans-cervical. Our case illustrates a patient who received IVTPA prior to attempted endovascular treatment, leading to a direct carotid cutdown for mechanical thrombectomy. Our patient presented with a left M1 occlusion and had received intravenous thrombolytic at the presentation of his symptoms. Due to unfavorable anatomy and tortuous aortic arch, conventional access could not be obtained. In order to achieve reperfusion while maintaining hemostasis, a decision was made to perform an open carotid cutdown to catherize the left internal carotid artery to successfully retrieve the thrombus. This resulted in a TICI2B revascularization. This is the first reported case of direct carotid access in the setting of acute ischemic stroke with IVTPA. Open technique allowed us to maintain hemostasis while bypassing the tortuous arch and achieving reperfusion and give the patient the best chance for a functional recovery.  相似文献   
68.
《Neurologic Clinics》2020,38(3):565-575
  相似文献   
69.
PurposeTo assess public preferences and perceptions regarding negative chest radiograph reports.MethodsUsing Amazon Mechanical Turk (Amazon Inc, Seattle, Washington), paid US English-speaking volunteers completed an 18-question survey. Participants were presented with the same two chest radiograph reports—one each in a freestyle and structured format—but randomized to one of four impression statements commonly used in our community. Participants were asked about content comprehension and confidence in the hypothetical interpreting radiologist.ResultsOver 15 days, 5,155 eligible participants completed the survey (of 6,363 respondents). Most reported prior chest radiography (68.9%) or any imaging (93.8%). Of those who underwent chest radiography, 77.6% reviewed their reports. Participants indicated structured reports were easier to comprehend (P < .001) but no difference in perceived confidence in the radiologist with freestyle versus structured reports (P = .21). No differences in comprehension were noted between different impressions with either freestyle (P = .077) or structured (P = .083) reports. Participants indicated higher confidence in radiologists when structured reports indicated “no acute disease” versus “unremarkable” (P = .049). When impressions stated “no acute disease,” participants indicated they would be more likely to do nothing, versus “negative chest” for which they indicated a higher likelihood of taking some action (P = .013, P = .04). Participant responses were similar for subgroups who previously underwent chest or other imaging and previously reviewed their imaging reports.ConclusionFor negative chest radiographs, structured reports are better comprehended by the public and less likely to prompt unnecessary follow-up. As patients increasingly access their medical records online, radiologist reporting should consider patient needs and behavior.  相似文献   
70.
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