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   2687篇
  免费   234篇
  国内免费   3篇
耳鼻咽喉   43篇
儿科学   60篇
妇产科学   41篇
基础医学   376篇
口腔科学   127篇
临床医学   285篇
内科学   504篇
皮肤病学   17篇
神经病学   195篇
特种医学   124篇
外科学   330篇
综合类   125篇
预防医学   249篇
眼科学   168篇
药学   205篇
中国医学   2篇
肿瘤学   73篇
  2022年   22篇
  2021年   70篇
  2020年   28篇
  2019年   40篇
  2018年   48篇
  2017年   46篇
  2016年   40篇
  2015年   70篇
  2014年   59篇
  2013年   101篇
  2012年   130篇
  2011年   124篇
  2010年   71篇
  2009年   59篇
  2008年   128篇
  2007年   108篇
  2006年   139篇
  2005年   137篇
  2004年   125篇
  2003年   112篇
  2002年   91篇
  2001年   88篇
  2000年   70篇
  1999年   54篇
  1998年   38篇
  1997年   30篇
  1996年   25篇
  1995年   35篇
  1994年   23篇
  1993年   14篇
  1992年   60篇
  1991年   41篇
  1990年   54篇
  1989年   39篇
  1988年   56篇
  1987年   40篇
  1986年   39篇
  1985年   45篇
  1984年   30篇
  1983年   30篇
  1981年   15篇
  1980年   14篇
  1979年   18篇
  1978年   16篇
  1977年   15篇
  1974年   15篇
  1972年   18篇
  1971年   18篇
  1970年   19篇
  1968年   18篇
排序方式: 共有2924条查询结果,搜索用时 15 毫秒
91.
Telemedicine is defined as the use of medical information exchanged from one site to another via electronic communications to improve delivery of care. This improvement in delivery of care is evident by more-efficient consults, triaging, and real-time communication between patient and surgeon. Internet-capable smartphones are capable of transferring radiographs and other images. Aziz and Ziccardi in 2009 demonstrated using smartphones for downloading images from the hospital archiving system to the resident's phone and then e-mailing or texting them to the attending for immediate review. Here we build on the work of Aziz and Ziccardi as we describe a novel use of smartphones for virtual rounding between residents and faculty based on improvements in technology, specifically video capability and increased accessibility of compatible devices.  相似文献   
92.
93.
We compared the ability of separately measured intimal-medial thickness and atherosclerotic plaque to predict incident cardiovascular disease. American Indian men and women from the Strong Heart Study who were free of cardiovascular disease were evaluated with carotid ultrasound and cardiovascular disease risk factor assessment. End-diastolic intimal-medial thickness of the common carotid arteries was measured and averaged. Arterial mass (cross-sectional area) was calculated from intimal-medial thickness and end-diastolic diameter. Atherosclerosis was defined by focal plaque (discrete thickening >50% relative to the adjacent wall) and the number of carotid segments containing plaque (plaque score); 2441 participants (age 63±8 years) were followed-up for a mean of 7.7±2.8 years, during which time 495 experienced incident cardiovascular disease events. Time-to-event analyses were performed in groups stratified according to diabetes and hypertension status. Cardiovascular disease events were predicted by presence and extent of atherosclerosis in all groups; intima-medial thickness and arterial mass were only associated with outcomes when neither hypertension nor diabetes was present. Unequivocal evidence of atherosclerosis (plaque) and its extent (plaque score) are independently associated with incident cardiovascular disease events in individuals without preexisting cardiovascular disease regardless of diabetes and hypertension status. Hypertension-related increases in intima-media thickness and arterial mass appear to limit their use as measures of early or diffuse atherosclerosis and, hence, association with cardiovascular disease outcomes. These findings support the utility of separate assessment of focal atherosclerosis and intimal-medial thickness in epidemiological studies, trials, and risk stratification protocols.  相似文献   
94.
BackgroundEspecially in older people, physicians are faced with the coexistence of type 2 diabetes mellitus (T2DM) and Parkinson's disease (PD). Therefore, this research aimed to compare diabetes endpoints between T2DM with and without PD.MethodsBased on the standardized, multicenter, prospective DPV database, 178,992 T2DM patients (≥40 years) were analyzed. 1579 were diagnosed with PD and/or received specific treatment. Hierarchical multivariable regression models were used for group comparisons; adjusted estimates based on observed marginal frequencies were calculated.ResultsPD patients were significantly older (77.9 vs. 70.0 years; p < 0.0001) and had a longer diabetes duration (10.3 vs. 8.4 years; p < 0.0001). In young PD patients (<50 years), percentage of females was significantly higher compared to age-matched T2DM patients without PD or people of the German population (66.7 vs. 38.1 vs. 49.0%; p < 0.0001, p < 0.02).After demographic adjustment, T2DM patients with PD showed a significantly lower HbA1c (58.0 vs. 60.3 mmol/mol; p < 0.0001), OAD/GLP-1 treatment (41.9 vs. 45.9%; p < 0.01) and frequency of dyslipidemia (62.0 vs. 64.5%; p < 0.05). In contrast, rates of insulin therapy (57.8 vs. 54.8%; p < 0.05), hypertension (73.3 vs. 68.6%; p < 0.001), antihypertensive medication (60.4 vs. 56.1%; p < 0.01), stroke (12.0 vs. 7.3%; p < 0.0001), dementia (9.2 vs. 2.6%; p < 0.0001) and repeated inpatient care (15.7 vs. 12.0%; p < 0.0001) were significantly higher and duration of hospital stay (6.2 vs. 4.7 days; p < 0.0001) was significantly longer in T2DM with PD.ConclusionClear demographic and clinical differences were observed between T2DM with and without PD. In PD patients, metabolic control is better, potentially due to more intensive medical care.  相似文献   
95.
Aims: Pannexins (Panx) form ATP release channels and it has been proposed that they play an important role in the regulation of vascular tone. However, distribution of Panx across the arterial vasculature is not documented. Methods: We tested antibodies against Panx1, Panx2 and Panx3 on human embryonic kidney cells (which do not endogenously express Panx proteins) transfected with plasmids encoding each Panx isoform and Panx1(-/-) mice. Each of the Panx antibodies was found to be specific and was tested on isolated arteries using immunocytochemistry. Results: We demonstrated that Panx1 is the primary isoform detected in the arterial network. In large arteries, Panx1 is primarily in endothelial cells, whereas in small arteries and arterioles it localizes primarily to the smooth muscle cells. Panx1 was the predominant isoform expressed in coronary arteries, except in arteries less than 100 μm where Panx3 became detectable. Only Panx3 was expressed in the juxtaglomerular apparatus and cortical arterioles. The pulmonary artery and alveoli had expression of all 3 Panx isoforms. No Panx isoforms were detected at the myoendothelial junctions. Conclusion: We conclude that the specific localized expression of Panx channels throughout the vasculature points towards an important role for these channels in regulating the release of ATP throughout the arterial network.  相似文献   
96.
We describe a novel deletion causing εγδβ thalassemia in a Pakistani family. The Pakistani deletion is 506kb in length, and the second largest εγδβ thalassemia deletion reported to date. It removes the entire β globin gene (HBB) cluster, extending from 431kb upstream to 75kb downstream of the ε globin gene (HBE). The breakpoint junction occurred within a 160bp palindrome embedded in LINE/LTR repeats, and contained a short (9bp) region of direct homology which may have contributed to the recombination event. Characterization of the deletion breakpoints has been particularly challenging due to the complexity of DNA deletion, insertion and inversion, involving a multitude of methodologies, mirroring the changing DNA analysis technologies.  相似文献   
97.
The objective of this systematic review was to assess the published literature on the effectiveness of exenatide twice daily (exenatide) in clinical practice, specifically its effects on haemoglobin A1c (A1C), fasting glucose (FG), weight, systolic blood pressure (SBP), medication use, hospitalization and cardiovascular disease (CVD) outcomes. A systematic literature search using the MEDLINE database of English language literature published between January 2005 and May 2011 was performed. The review included retrospective or prospective observational studies that included 100 or more patients per treatment group. A total of 15 studies meeting the inclusion criteria were identified. The studies revealed significant reductions of -0.4 to -0.9% in A1C, -10 mg/dl in FG, -2 to -11 kg in body weight and -2 to -11 mmHg in SBP. Statistically significant reductions in the use or dosage of either oral glucose-lowering medications or insulin after initiating exenatide treatment were found in every observational study that assessed medication changes, including reductions in dosage of up to 75% in sulphonylureas dosages, 22% in metformin, 66% in thiazolidinediones (TZD) or TZD combination therapy and 75% in prandial insulin. Exenatide-treated patients experienced significantly lower rates of all-cause and CVD-related hospitalization and CVD events than patients treated with other therapies overall. In this review of observational studies, exenatide initiation was associated with significant reductions in clinically relevant outcomes. Improvements in A1C, FG, weight and SBP in the observational studies in this review were consistent with improvements observed in controlled clinical trials.  相似文献   
98.
In the literature on repetition priming of word-production in normal participants, long-lasting effects can be found from a single prime. This contrasts with the findings with adults with anomia (as part of their aphasia) where phonological cues, such as first sound or rhyme, have been shown to have very short-lasting effects on word retrieval (Patterson, Purell, & Morton, 1983). In addition, the research into treatment of anomia suggests that semantic techniques produce longer-lasting effects than phonological techniques (Howard et al., 1985b). One difference between phonological and semantic techniques is in the element of choice available. Typically phonological cues are simply provided. This contrasts with semantic techniques where a choice is available, for example selecting from a set of pictures to match a word. This study, using a case series design, set out to replicate the finding, that phonological techniques have only short-lasting effects on word retrieval in aphasia and to investigate the influence of providing a choice of cues. Items that participants with aphasia were unable to name after 5 seconds were allocated to one of three conditions: extra time (control condition), single cue, and choice of two cues. Naming was assessed immediately and at a delay (over 10 minutes later). Four different cue types were used: whole word, spoken CV, written CV, and rime. The results were surprising. The cues influenced immediate naming, as predicted. However, this effect was still significant a delayed naming. Additionally, the benefits from a choice of cues were generally similar to those from a single cue. Different patterns of cue effectiveness were found for different participants. Further investigations shed some light on the mechanisms of cueing, orthographic cueing in particular.  相似文献   
99.
This paper describes the rationale, development, and implementation of a group parent training program designed to assist caregivers in the management of their child's eating disorder while facilitating the development of a healthy home environment for sustained change. The content of this program instructs caregivers in disorder management and capitalizes on caregivers as role models of adaptive behavior. Strategies are provided to address acute disorder management, features of caregivers that may impede task implementation, and environmental and attitudinal changes. The group format enhances social support, accountability, and self-efficacy. A preliminary qualitative evaluation and future directions are described to assist healthcare professionals in better meeting the needs of caregivers of these disorders.  相似文献   
100.
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