全文获取类型
收费全文 | 95312篇 |
免费 | 3859篇 |
国内免费 | 269篇 |
专业分类
耳鼻咽喉 | 1152篇 |
儿科学 | 1994篇 |
妇产科学 | 2693篇 |
基础医学 | 8334篇 |
口腔科学 | 2733篇 |
临床医学 | 9527篇 |
内科学 | 20154篇 |
皮肤病学 | 2083篇 |
神经病学 | 8311篇 |
特种医学 | 5025篇 |
外国民族医学 | 2篇 |
外科学 | 20437篇 |
综合类 | 902篇 |
现状与发展 | 1篇 |
一般理论 | 16篇 |
预防医学 | 3485篇 |
眼科学 | 2428篇 |
药学 | 2448篇 |
5篇 | |
中国医学 | 197篇 |
肿瘤学 | 7513篇 |
出版年
2024年 | 99篇 |
2023年 | 4765篇 |
2022年 | 6876篇 |
2021年 | 6953篇 |
2020年 | 8074篇 |
2019年 | 4631篇 |
2018年 | 3936篇 |
2017年 | 3970篇 |
2016年 | 3972篇 |
2015年 | 3255篇 |
2014年 | 7787篇 |
2013年 | 5370篇 |
2012年 | 3333篇 |
2011年 | 2662篇 |
2010年 | 4415篇 |
2009年 | 4164篇 |
2008年 | 2078篇 |
2007年 | 2077篇 |
2006年 | 1885篇 |
2005年 | 1458篇 |
2004年 | 1229篇 |
2003年 | 1332篇 |
2002年 | 1229篇 |
2001年 | 1168篇 |
2000年 | 1066篇 |
1999年 | 1206篇 |
1998年 | 809篇 |
1997年 | 667篇 |
1996年 | 708篇 |
1995年 | 638篇 |
1994年 | 486篇 |
1993年 | 393篇 |
1992年 | 528篇 |
1991年 | 507篇 |
1990年 | 501篇 |
1989年 | 484篇 |
1988年 | 512篇 |
1987年 | 366篇 |
1986年 | 317篇 |
1985年 | 299篇 |
1984年 | 344篇 |
1983年 | 251篇 |
1982年 | 268篇 |
1981年 | 238篇 |
1980年 | 215篇 |
1979年 | 191篇 |
1978年 | 163篇 |
1977年 | 120篇 |
1976年 | 136篇 |
1975年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Oren S Cohen Eli Vakil David Tanne Zeev Nitsan Roseline Schwartz Sharon Hassin-Baer 《Cognitive and behavioral neurology》2007,20(1):68-72
OBJECTIVES: To test a possible association between the educational level (EL), cognitive performance, and neuropsychiatric features in Parkinson disease (PD). BACKGROUND: An inverse association has been reported between EL and cognitive dysfunction in patients with senile dementia of Alzheimer type but it is yet unsettled whether education has a similar effect on cognition in PD. METHODS: Seventy-two PD patients (45 males, mean age 68.7+/-11.6 y) underwent a detailed neurologic examination, a battery of neuropsychologic tests, and questionnaires for the evaluation of psychosis, sleep disturbances, and depression. According to the number of educational years, patients were divided into 3 groups: low EL (0 to 8 y), (15 patients), intermediate EL (9 to 12 y) (28 patients), and high EL (>/=13 y) (29 patients). RESULTS: Patients with a higher EL had a better cognitive function and an association was found between the patients' EL and their scores in various neuropsychologic tests mainly those sensitive to frontal lobe dysfunction. Low education was associated with an increased risk for hallucinations and a trend for more depression, delusions, and sleep disturbances. CONCLUSIONS: The association between high educational attainment and the lower risk of cognitive dysfunction suggest that education might modulate cognitive performance in PD. 相似文献
82.
Peter B. Richman MD Shari Dominguez MD David Kasper MD Frederick Chen MD Jeremy Friese MD Joseph Wood MD JD Joseph Collins MD Jeffrey A. Kline MD 《Academic emergency medicine》2006,13(3):295-301
Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献
83.
84.
《Indian Journal of Rheumatology》2007,2(2):55-64
Since the triggering factors causing primary vasculitides are by definition not (yet) known, we have to classify them to clinical syndromes based on the size, site, type and effect of the blood vessel involvement. ACR classification criteria and Chapel Hill nomenclature are useful tools to familiarize with the primary vasculitides, although a lot of criticism has been voiced in the literature indicating that they only represent the best available consensus. The present text takes advantage of the recent developments such as introduction of the anti-neutrophilic cytoplasmic auto (ANCA) antibodies, and divides the vasculitides to those affecting typically the large, medium and small arteries or only small blood vessels. In addition, some vasculitides, which are still difficult to place to the vasculitis map, like Bürger's disease, Goodpasture's syndrome, primary angiitin of the central nervous system (PACNS) and panniculitis, are dealt with. As it is a long and winding road, attention has to be paid to the clinical details to follow the road sign to “pseudovasculitis”, when that is the right way to go. They represent a bunch of non-vasculitic conditions, which lead to structural or vasospastic impairment of the blood flow, bleeding or thromboembolism and hyperviscosity. These imitators have to some extent, similar clinical symptoms and signs as well as laboratory and radiological findings to those found in true systemic vasculitides. This also emphasizes the importance of internal medicine as the intellectual (albeit not necessarily organizational) home of rheumatology and rheumatologists as we deal with conditions like atherosclerosis, antiphospholipid antibody syndrome, infectious endocarditic, myxoma of the heart and cholesterol embolism. 相似文献
85.
86.
《Anaesthesia and Intensive Care Medicine》2007,8(1):21-23
Early recognition of patients at risk of catastrophic deterioration leads to early treatment and improved prognosis. Delayed identification of critically ill patients and their delayed referral to intensive care are causes of increased mortality. Systematic assessment of patients at risk is a prerequisite for early recognition of critical illness. The assessment of the critically ill patient should follow the ‘Airway Breathing Circulation’ format. A blocked airway, raised respiratory rate and a systolic blood pressure that is smaller than the heart rate are signs of critical illness. Confusion and raised respiratory rate are the signs that most strongly indicate critical illness and are the most often missed during assessment. The assessment of critical illness is supplemented by risk factors, which result from concomitant chronic conditions, and haematological and biochemical tests, ECGs and radiographs. Lactate has a particular role in triage of patients with sepsis. For those clinicians inexperienced in critical care, simple scoring systems allow rapid assessment of the degree of physiological abnormality and the associated risk. 相似文献
87.
88.
89.
José Abal Arca Isaura Parente Lamelas Raquel Almazán Ortega José Blanco Pérez María Elena Toubes Navarro Pedro Marcos Velázquez 《Archivos de bronconeumologia》2009,45(10):502-507
Background and objectiveTo analyse frequency, characteristics and patient survival with lung cancer (LC) and Common Obstructive Pulmonary Disease (COPD), comparing them with patients that do not have COPD.Material and methodsA retrospective study, of patients diagnosed by means of cytohistology. Survival was estimated by the Kaplan-Meier method. Statistical analysis was carried out using SPSS 15.0.ResultsA total of 996 patients were diagnosed, 39.8% with COPD. Mean age70±9.19 years. GOLD stages: I 18.2%, II 53.6%, III 24%, IV 4.2%. The histological types: squamous cell carcinoma 48.2%, adenocarcinoma 22%, and small cell carcinoma 22.5%. Survival was longer in the COPD group.ConclusionsLC and COPD are combined in 39.8%. Squamous cell type is more frequent and survival was longer in the COPD group. 相似文献
90.