全文获取类型
收费全文 | 3049篇 |
免费 | 314篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 97篇 |
妇产科学 | 59篇 |
基础医学 | 330篇 |
口腔科学 | 58篇 |
临床医学 | 262篇 |
内科学 | 454篇 |
皮肤病学 | 28篇 |
神经病学 | 384篇 |
特种医学 | 152篇 |
外科学 | 573篇 |
综合类 | 73篇 |
预防医学 | 279篇 |
眼科学 | 34篇 |
药学 | 290篇 |
肿瘤学 | 293篇 |
出版年
2022年 | 25篇 |
2021年 | 36篇 |
2020年 | 27篇 |
2019年 | 36篇 |
2018年 | 43篇 |
2017年 | 39篇 |
2016年 | 48篇 |
2015年 | 34篇 |
2014年 | 64篇 |
2013年 | 92篇 |
2012年 | 113篇 |
2011年 | 136篇 |
2010年 | 54篇 |
2009年 | 66篇 |
2008年 | 115篇 |
2007年 | 113篇 |
2006年 | 120篇 |
2005年 | 124篇 |
2004年 | 120篇 |
2003年 | 109篇 |
2002年 | 127篇 |
2001年 | 117篇 |
2000年 | 136篇 |
1999年 | 81篇 |
1998年 | 57篇 |
1997年 | 37篇 |
1996年 | 46篇 |
1995年 | 45篇 |
1994年 | 35篇 |
1993年 | 33篇 |
1992年 | 85篇 |
1991年 | 84篇 |
1990年 | 85篇 |
1989年 | 86篇 |
1988年 | 75篇 |
1987年 | 72篇 |
1986年 | 55篇 |
1985年 | 52篇 |
1984年 | 42篇 |
1983年 | 40篇 |
1982年 | 35篇 |
1981年 | 31篇 |
1980年 | 22篇 |
1979年 | 25篇 |
1978年 | 23篇 |
1977年 | 30篇 |
1975年 | 21篇 |
1974年 | 22篇 |
1972年 | 23篇 |
1970年 | 23篇 |
排序方式: 共有3388条查询结果,搜索用时 15 毫秒
61.
Background
The intensive care nursing workforce plays an essential role in the achievement of positive healthcare outcomes. A growing body of evidence indicates that inadequate nurse staffing and poor skill mix are associated with negative outcomes for patients, and potentially compromises nurses’ ability to maintain the safety of those in their care. In Australia, the Australian College of Critical Care Nurses (ACCCN) has previously published a position statement on intensive care staffing. There was a need for a stronger more evidence based document to support the intensive nursing workforce.Objectives
To undertake a systematic and evidence review of the evidence related to intensive care nurse staffing and quality of care, and determine evidence-based professional standards for the intensive care nursing workforce in Australia.Methods
The National Health and Medical Research Council standard for clinical practice guidelines methodology was employed. The English language literature, for the years 2000-2015 was searched. Draft standards were developed and then peer- and consumer-reviewed.Results
A total of 553 articles was retrieved from the initial searches. Following evaluation, 231 articles met the inclusion criteria and were assessed for quality using established criteria. This evidence was used as the basis for the development of ten workforce standards, and to establish the overall level of evidence in support of each standard. All draft standards and their subsections were supported multi-professionally (median score >6) and by consumers (85–100% agreement). Following minor revisions, independent appraisal using the AGREE II tool indicated that the standards were developed with a high degree of rigour.Conclusion
The ACCCN intensive care nursing nurse workforce standards are the first to be developed using a robust, evidence-based process. The standards represent the optimal nurse workforce to achieve the best patient outcomes and to maintain a sustainable intensive care nursing workforce for Australia. 相似文献62.
Desmond A. Brown Benjamin T. Himes Brittny T. Major Benjamin F. Mundell Ravi Kumar Bruce Kall Fredric B. Meyer Michael J. Link Bruce E. Pollock John D. Atkinson Jamie J. Van Gompel W. Richard Marsh Giuseppe Lanzino Mohamad Bydon Ian F. Parney 《Mayo Clinic proceedings. Mayo Clinic》2018,93(1):16-24
Objective
To determine adverse event rates for adult cranial neuro-oncologic surgeries performed at a high-volume quaternary academic center and assess the impact of resident participation on perioperative complication rates.Patients and Methods
All adult patients undergoing neurosurgical intervention for an intracranial neoplastic lesion between January 1, 2009, and December 31, 2013, were included. Cases were categorized as biopsy, extra-axial/skull base, intra-axial, or transsphenoidal. Complications were categorized as neurologic, medical, wound, mortality, or none and compared for patients managed by a chief resident vs a consultant neurosurgeon.Results
A total of 6277 neurosurgical procedures for intracranial neoplasms were performed. After excluding radiosurgical procedures and pediatric patients, 4151 adult patients who underwent 4423 procedures were available for analysis. Complications were infrequent, with overall rates of 9.8% (435 of 4423 procedures), 1.7% (73 of 4423), and 1.4% (63 of 4423) for neurologic, medical, and wound complications, respectively. The rate of perioperative mortality was 0.3% (14 of 4423 procedures). Case performance and management by a chief resident did not negatively impact outcome.Conclusion
In our large-volume brain tumor practice, rates of complications were low, and management of cases by chief residents in a semiautonomous manner did not negatively impact surgical outcomes. 相似文献63.
64.
This study compared functional capacity during treadmill exercise testing and during bicycle exercise radionuclide angiography. 262 patients performed maximal upright bicycle exercise and also performed maximal graded exercise testing using either the Bruce (n = 158) or Naughton (n = 104) treadmill protocols. The functional capacity was well correlated between bicycle and treadmill for Bruce (r = 0.89), Naughton (r = 0.93), or combined treadmill (r = 0.90) protocols. However, the functional capacity was significantly lower during bicycle than during treadmill testing for Bruce (8.3 vs. 10.5 METs), Naughton (7.8 vs. 8.7 METs), or combined treadmill (8.1 vs. 9.8 METs) protocols. Treadmill functional capacity could be predicted from bicycle functional capacity using the following equations: Bruce METs = 1.00 X (bike METs) + 2.23, Naughton METs = 0.94 X (bike METs) + 1.40, and combined treadmill METs = 0.98 X (bike METs) + 1.85. 相似文献
65.
A model to predict multivessel coronary artery disease from the exercise thallium-201 stress test 总被引:1,自引:0,他引:1
S G Pollock R D Abbott C A Boucher D D Watson S Kaul 《The American journal of medicine》1991,90(3):345-352
PURPOSE: The aim of this study was to (1) determine whether nonimaging variables add to the diagnostic information available from exercise thallium-201 images for the detection of multivessel coronary artery disease; and (2) to develop a model based on the exercise thallium-201 stress test to predict the presence of multivessel disease. PATIENTS AND METHODS: The study populations included 383 patients referred to the University of Virginia and 325 patients referred to the Massachusetts General Hospital for evaluation of chest pain. All patients underwent both cardiac catheterization and exercise thallium-201 stress testing between 1978 and 1981. RESULTS: In the University of Virginia cohort, at each level of thallium-201 abnormality (no defects, one defect, more than one defect), ST depression and patient age added significantly in the detection of multivessel disease. Logistic regression analysis using data from these patients identified three independent predictors of multivessel disease: initial thallium-201 defects, ST depression, and age. A model was developed to predict multivessel disease based on these variables. As might be expected, the risk of multivessel disease predicted by the model was similar to that actually observed in the University of Virginia population. More importantly, however, the model was accurate in predicting the occurrence of multivessel disease in the unrelated population studied at the Massachusetts General Hospital. CONCLUSION: It is, therefore, concluded that (1) nonimaging variables (age and exercise-induced ST depression) add independent information to thallium-201 imaging data in the detection of multivessel disease; and (2) a model has been developed based on the exercise thallium-201 stress test that can accurately predict the probability of multivessel disease in other populations. 相似文献
66.
L Esquivel S G Pollock G A Beller R S Gibson D D Watson S Kaul 《The American journal of cardiology》1989,63(3):160-165
The sensitivity of ST-segment depression on the electrocardiogram during exercise is influenced by the level of effort. Whether such is the case with thallium-201 imaging (initial defect or redistribution) has not been established. Accordingly, the prevalence of these parameters was evaluated in 288 patients (age 59 +/- 10 years, 88% men) with coronary artery disease who underwent both exercise thallium-201 imaging and coronary angiography within 3 months of each other: 159 had a prior myocardial infarction, 72 had 1-vessel, and 216 had multivessel disease. The degree of effort was evaluated by 3 criteria: (1) percentage of maximal predicted heart rate (less than or equal to 65, greater than 65 to 85, greater than 85%); (2) workload during exercise (less than or equal to 4, greater than 4 to 8, greater than 8 METs); and (3) duration of exercise (less than or equal to 3, greater than 3 to 6, greater than 6 minutes). The prevalence of defects on initial images was higher than both redistribution on delayed images and ST-segment depression on the electrocardiogram (p less than 0.01). The overall prevalence of initial defects remained the same for all levels of effort and was not influenced by the presence or absence of a prior infarction. However, it decreased in patients with 1-vessel disease who exercised to higher workloads. The prevalence of redistribution on delayed thallium-201 images was higher than that of ST-segment depression on the electrocardiogram (p less than 0.01), except at higher levels of effort where they were similar.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
67.
Summary The distribution of type IV collagen and laminin in the intimal layer of rheumatoid, osteoarthritic, traumatic and normal human synovium was determined by immunohistochemistry using polyclonal and monoclonal antibodies. All samples showed a similar pattern of labelling with type IV collagen and laminin present around the synovial intimal cells. Type IV collagen has previously only been identified in association with basement membranes which are not found at this site. Two major basement membrane components around synovial cells suggest the formation of a modified basement membrane-like structure. 相似文献
68.
Transoesophageal echocardiographic assessment of primum, secundum and sinus venosus atrial septal defects 总被引:2,自引:0,他引:2
J P Gnanapragasam A B Houston D B Northridge M P Jamieson J C Pollock 《International journal of cardiology》1991,31(2):167-174
We compared the ability of transthoracic and transoesophageal echocardiography to determine the presence and site of an atrial septal defect and associated anomalous pulmonary venous connexions in 13 school age children (aged 5 to 15 years) and 12 adults (aged 25 to 68 years). Transthoracic echocardiography detected atrial septal defects in 12 children and 6 adults. Transoesophageal echocardiography confirmed the position of 16 (13 secundum, 3 primum) of these 18 defects but altered the diagnosis from a secundum defect to a sinus venosus defect in one and from a sinus venosus defect to a high secundum defect in another. In addition to these 18, transoesophageal echocardiography diagnosed a defect in 5 adults (3 secundum and 2 sinus venosus defects) and 1 child (secundum defect). In an adult with inconclusive transthoracic findings, transoesophageal echocardiography enabled clear visualisation of the atrial septum and excluded an atrial septal defect. Transoesophageal echocardiography showed anomalous attachment of a pulmonary vein into the region of a sinus venosus defect (n = 3) but did not show anomalous connexions to the superior caval vein (n = 3) or the inferior caval vein (n = 1). Transoesophageal echocardiography provides a reliable method of diagnosing or excluding an atrial septal defect in patients with inconclusive transthoracic findings and is of particular diagnostic value in sinus venosus defects. 相似文献
69.
70.