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   22572篇
  免费   1657篇
  国内免费   332篇
耳鼻咽喉   276篇
儿科学   627篇
妇产科学   241篇
基础医学   2136篇
口腔科学   381篇
临床医学   3576篇
内科学   2363篇
皮肤病学   221篇
神经病学   5287篇
特种医学   461篇
外科学   1433篇
综合类   2567篇
一般理论   3篇
预防医学   2421篇
眼科学   127篇
药学   1411篇
  18篇
中国医学   664篇
肿瘤学   348篇
  2023年   527篇
  2022年   901篇
  2021年   1397篇
  2020年   1272篇
  2019年   1229篇
  2018年   1216篇
  2017年   1170篇
  2016年   959篇
  2015年   795篇
  2014年   1889篇
  2013年   2073篇
  2012年   1326篇
  2011年   1606篇
  2010年   1048篇
  2009年   1086篇
  2008年   1020篇
  2007年   862篇
  2006年   650篇
  2005年   510篇
  2004年   412篇
  2003年   358篇
  2002年   268篇
  2001年   239篇
  2000年   170篇
  1999年   141篇
  1998年   115篇
  1997年   90篇
  1996年   91篇
  1995年   88篇
  1994年   82篇
  1993年   80篇
  1992年   53篇
  1991年   47篇
  1990年   57篇
  1989年   31篇
  1988年   40篇
  1987年   33篇
  1985年   70篇
  1984年   65篇
  1983年   45篇
  1982年   52篇
  1981年   31篇
  1980年   43篇
  1979年   56篇
  1978年   40篇
  1977年   30篇
  1976年   40篇
  1975年   41篇
  1974年   29篇
  1973年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Functional Near Infrared Spectroscopy (fNIRS) is an important neuroimaging technique in cognitive developmental neuroscience. Nevertheless, there is no general consensus yet about best pre-processing practices. This issue is highly relevant, especially since the development and variability of the infant hemodynamic response (HRF) is not fully known. Systematic comparisons between analysis methods are thus necessary. We investigated the performance of five different pipelines, selected on the basis of a systematic search of the infant NIRS literature, in two experiments. In Experiment 1, we used synthetic data to compare the recovered HRFs with the true HRF and to assess the robustness of each method against increasing levels of noise. In Experiment 2, we analyzed experimental data from a published study, which assessed the neural correlates of artificial grammar processing in newborns. We found that with motion artifact correction (as opposed to rejection) a larger number of trials were retained, but HRF amplitude was often strongly reduced. By contrast, artifact rejection resulted in a high exclusion rate but preserved adequately the characteristics of the HRF. We also found that the performance of all pipelines declined as the noise increased, but significantly less so than if no pre-processing was applied. Finally, we found no difference between running the pre-processing on optical density or concentration change data. These results suggest that pre-processing should thus be optimized as a function of the specific quality issues a give dataset exhibits.  相似文献   
12.
Recently, there has been a call for research-informed and research-developed practice in health sciences education. This prompts the consideration of alternative suitable research approaches that could be used to enhance health sciences education practice, including medical radiation sciences education (MRSE) practice. In this discussion paper, the authors uphold design science research (DSR) methodology as a suitable research approach to enhance MRSE practice and research. An overview of the DSR methodology and an example of a project that used DSR methodology are presented to demonstrate the application of this methodology in MRSE practice and research. The paper concludes that the use of DSR methodology could be instrumental in addressing practice related challenges while developing a theoretical contribution to the discipline.  相似文献   
13.
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored.  相似文献   
14.
《Clinical neurophysiology》2021,132(2):315-322
ObjectivePrevious studies have demonstrated voluntary movement alterations as well as motor cortex excitability and plasticity changes in patients with mild cognitive impairment (MCI). To investigate the pathophysiology of movement abnormalities in MCI, we tested possible relationships between movement abnormalities and primary motor cortex alterations in patients.MethodsFourteen amnestic MCI (aMCI) patients and 16 healthy controls were studied. Cognitive assessment was performed using clinical scales. Finger tapping was recorded by a motion analysis system. Transcranial magnetic stimulation was used to test the input/output curve of motor evoked potentials, intracortical inhibition, and short-latency afferent inhibition. Primary motor cortex plasticity was probed by theta burst stimulation. We investigated correlations between movement abnormalities, clinical scores, and cortical neurophysiological parameters.ResultsMCI patients showed less rhythmic movement but no other movement abnormalities. Cortical excitability measures were normal in patients, whereas plasticity was reduced. Movement rhythm abnormalities correlated with frontal dysfunction scores.ConclusionOur study in MCI patients demonstrated abnormal voluntary movement and plasticity changes, with no correlation between the two. Altered rhythm correlated with frontal dysfunction.SignificanceOur results contribute to the understanding of pathophysiological mechanisms of motor impairment in MCI.  相似文献   
15.
16.
Background/objectiveObstructive sleep apnea (OSA) is independently associated with dyslipidemia, a surrogate marker of atherosclerosis. Low-density lipoprotein (LDL)-cholesterol is accepted as a major independent risk factor for cardiovascular disease. However, non-high-density lipoprotein (HDL)-cholesterol is a better marker of atherogenic dyslipidemia and recommended as a target of lipid lowering therapy. We aimed to assess the prevalence of atherogenic dyslipidemia, and relationship between OSA severity and serum LDL-cholesterol and non-HDL cholesterol levels in OSA patients.MethodsWe retrospectively evaluated treatment naïve 2361 subjects admitted to the sleep laboratory of a university hospital for polysomnography. All subjects’ lipid profile including total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and non-HDL-cholesterol were measured.ResultsOut of 2361 patients (mean age 49.6 ± 11.9 years; 68.9% male, apnea-hypopnea index 36.6 ± 28.4/h), 185 (7.8%) had no OSA and 2176 (92.2%) had OSA. Atherogenic dyslipidemia prevalence was high (57–66%) in OSA patients, and especially increased in severe OSA compared to other groups (p < 0.05). Though total and LDL-cholesterol did not differ between those with and without OSA, non-HDL-cholesterol (p = 0.020), and triglycerides (p = 0.001) were higher and HDL-cholesterol levels (p = 0.018) were lower in OSA patients than non-OSA. Non-HDL-cholesterol was significantly correlated with OSA severity (p < 0.001) and hypoxia parameters (p < 0.01), whereas LDL-cholesterol showed no correlation.ConclusionsAtherogenic dyslipidemia is highly prevalent and non-HDL-cholesterol levels are significantly increased, predominantly in severe OSA patients. Non-HDL-cholesterol but not LDL-cholesterol, is significantly correlated with OSA severity and hypoxia parameters. Therefore, it could be better to use non-HDL-cholesterol, which is a guideline recommended target of lipid therapy, as a marker of atherosclerotic cardiovascular risk in OSA patients.  相似文献   
17.
AimTo compare the efficacy and acceptability of internet-delivered exposure therapy for panic disorder, to multi-component internet-delivered cognitive behavioral therapy (iCBT) that included controlled breathing, cognitive restructuring and exposure.MethodsParticipants with panic disorder, with or without agoraphobia, were randomized to internet-delivered exposure therapy (n = 35) or iCBT (n = 34). Both programs were clinician guided, with six lessons delivered over eight weeks. Outcomes included panic disorder and agoraphobia symptom severity, as well as depression symptom severity, functional impairment and days out of role.ResultsParticipants in both conditions displayed a large reduction in panic disorder symptom severity (ds >1.30) from pre- to post-treatment. Participants in both conditions displayed medium to large reduction in agoraphobia and depression symptom severity, functional impairment and days out of role. Effects were maintained at three- and six-month follow-up. There was no significant difference between the interventions in clinical outcomes, adherence or treatment satisfaction.ConclusionsInternet-delivered exposure therapy appeared to be as acceptable and efficacious as more established iCBT, despite including less strategies. However, a fully powered replication is now needed to compare the two approaches.  相似文献   
18.
Background and aimsObesity and overweight in children are associated with an increased risk of several health issues. The present study aimed to assess the effects of a multi-disciplinary program (including nutrition education using a smartphone game, physical activity, and cognitive behavioral therapy [CBT]) on the management of obesity and overweight in elementary school girls.Methods and resultsSixty-two school girls above the 85th percentile of body mass index (BMI) for age were randomly assigned to two groups. During 10 weeks of study, the intervention group received a multi-disciplinary intervention, including nutrition education using a smartphone game, aerobic exercise, and CBT. The control group received usual traditional nutritional education. Biochemical and metabolic factors were assessed, including fasting blood sugar (FBS), lipid profile, serum leptin, and anthropometric measurements. The Dutch Eating Behavior Questionnaire (DEBQ) and metabolic equivalent test (MET) were also conducted. The intervention group showed more promising results in weight loss, waist circumference (WC), hip circumference (HC), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), and FBS compared to the control group (P < 0.05). In addition, MET and DEBQ scores in all three sections of emotions, stimuli, and restriction were better in the intervention group than in the control group (P < 0.05). However, there was no significant difference between groups regarding the results of serum leptin and waist-to-hip ratio (WHR; p > 0.05).ConclusionsThe results indicated that education through smartphone games could possibly affect performance in real life. In addition, the multi-disciplinary approach to childhood obesity might have better performance in most areas than the single-intervention approach in obesity management.  相似文献   
19.
BackgroundThe growing enthusiasm for the use of reverse shoulder arthroplasty (RSA) in the treatment of primary glenohumeral osteoarthritis (GHOA) with an intact rotator cuff is based on data derived from single-center studies with limited generalizability and follow-up. This study compared patient-reported outcomes (PROs) between RSA and total shoulder arthroplasty (TSA) for the treatment of primary GHOA with up to 5-year follow-up and examined temporal trends in the treatment of GHOA between 2012 and 2021.MethodsA retrospective review was performed on patients with primary GHOA undergoing primary arthroplasty surgery from the Surgical Outcomes System global registry between 2012 and 2021. PROs including the American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE) score, and visual analog scale (VAS) for pain were compared between RSA and TSA at 1, 2, and 5 years postoperatively.ResultsA total of 4451 patients were included, with 2693 (60.5%) undergoing TSA and 1758 (39.5%) undergoing RSA. Both RSA and TSA provided clinically excellent outcomes at 1 year postoperatively (ASES: 80.8 ± 17.9 vs. 85.9 ± 15.2, respectively; SANE: 74.8 ± 24.7 vs. 79.5 ± 22.9; VAS pain: 1.3 ± 2.0 vs. 1.1 ± 1.7; all P < .05) that were maintained at 2 years (ASES: 81.3 ± 19.3 vs. 87.3 ± 14.9; SANE: 74.8 ± 26.2 vs. 79.7 ± 24.7; VAS pain: 1.3 ± 2.1 vs. 1.0 ± 1.6; all P < .05) and 5 years (ASES: 81.7 ± 16.5 vs. 86.9 ± 15.3; SANE: 71.6 ± 28.5 vs. 78.2 ± 25.9; VAS pain: 1.0 ± 1.7 vs. 1.0 ± 1.7; all P < .05), with statistical significance favoring TSA. After controlling for age and sex, there was an adjusted difference of 4.5 units in the ASES score favoring TSA (P = .005) at 5 years postoperatively but no differences in adjusted SANE (P = .745) and VAS pain (P = .332) scores. The use of RSA for GHOA grew considerably over time, from representing only 17% of all replacements performed for GHOA in 2012 to nearly half (47%) in 2021 (P < .001).ConclusionRSA as a treatment for GHOA with an intact rotator cuff seems to yield PROs that are largely clinically equivalent to TSA extending to 5 years postoperatively. The observed statistical significance favoring TSA appears to be of marginal clinical benefit based on established minimal clinically important differences and may be a result of the large sample size. Further research using more granular clinical data and examining differences in range of motion and complications is warranted as it may change the value analysis.  相似文献   
20.
杨双  胡爱萍  向明芳 《中国全科医学》2022,25(31):3965-3970
亲密伴侣暴力(IPV)是指亲密伴侣之间发生的威胁或虐待行为,其具体形式包括身体、精神或性伤害。现有研究表明,IPV可给受害者带来一系列身体和心理上的损伤,严重影响受害者的生活质量。准确评估IPV是制定针对性预防措施的前提和基础。然而,国内对IPV的研究尚处于起步阶段,针对IPV的评估工具缺乏。本文将国外常用的8种IPV评估工具分为研究工具和筛查工具,对各工具的主要内容、应用情况及特点进行综述,并对这8种评估工具的优缺点进行比较,旨在为我国IPV相关研究提供借鉴,为准确评估和识别IPV受害者提供依据。  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