全文获取类型
收费全文 | 40020篇 |
免费 | 3467篇 |
国内免费 | 120篇 |
专业分类
耳鼻咽喉 | 514篇 |
儿科学 | 1102篇 |
妇产科学 | 786篇 |
基础医学 | 5279篇 |
口腔科学 | 1027篇 |
临床医学 | 4289篇 |
内科学 | 7937篇 |
皮肤病学 | 416篇 |
神经病学 | 3981篇 |
特种医学 | 1585篇 |
外国民族医学 | 3篇 |
外科学 | 5691篇 |
综合类 | 761篇 |
一般理论 | 30篇 |
预防医学 | 4183篇 |
眼科学 | 1115篇 |
药学 | 2648篇 |
中国医学 | 46篇 |
肿瘤学 | 2214篇 |
出版年
2021年 | 417篇 |
2020年 | 323篇 |
2019年 | 463篇 |
2018年 | 507篇 |
2017年 | 402篇 |
2016年 | 450篇 |
2015年 | 617篇 |
2014年 | 949篇 |
2013年 | 1540篇 |
2012年 | 2074篇 |
2011年 | 2355篇 |
2010年 | 1259篇 |
2009年 | 1246篇 |
2008年 | 2141篇 |
2007年 | 2392篇 |
2006年 | 2418篇 |
2005年 | 2444篇 |
2004年 | 2280篇 |
2003年 | 2251篇 |
2002年 | 2299篇 |
2001年 | 636篇 |
2000年 | 538篇 |
1999年 | 605篇 |
1998年 | 540篇 |
1997年 | 465篇 |
1996年 | 429篇 |
1995年 | 428篇 |
1994年 | 403篇 |
1993年 | 379篇 |
1992年 | 444篇 |
1991年 | 429篇 |
1990年 | 403篇 |
1989年 | 401篇 |
1988年 | 395篇 |
1987年 | 391篇 |
1986年 | 411篇 |
1985年 | 428篇 |
1984年 | 452篇 |
1983年 | 437篇 |
1982年 | 530篇 |
1981年 | 501篇 |
1980年 | 486篇 |
1979年 | 372篇 |
1978年 | 355篇 |
1977年 | 351篇 |
1976年 | 274篇 |
1975年 | 265篇 |
1974年 | 294篇 |
1973年 | 294篇 |
1972年 | 250篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Donald R. Vogenthaler 《Brain injury : [BI]》1987,1(1):113-127
This article provides a broad overview of the consequences of head injury and approaches to its rehabilitation. Of necessity, no specific area is covered in depth. Sufficient references are provided, however, for the reader who desires further information in any of the areas discussed. It is hoped that, by providing this broad overview, the reader will develop a generalized picture of head injury rehabilitation. Furthermore, the article is designed for 'novices' in the field of head injury rehabilitation such as (1) the family/significant others of the injured persons—so they may begin to know what to expect and to plan for appropriate services; (2) the rehabilitation student—so he or she may be introduced to this emerging specialization and thereby make more informed career choices; and (3) perhaps most important, the newly hired, novice head injury practitioner. This article could form the nucleus of an orientation or in-service training programme for new employees who are not sufficiently knowledgeable in this specialization. In-service programmes are often a necessity for new employees (even on the graduate level) because of the recent, large increase in the number of facilities and programmes specializing in head injury rehabilitation, and because of the lack of available head injury rehabilitation education and training programmes. 相似文献
62.
63.
The results of conventional cerebrospinal fluid (CSF) investigations (CSF cell count, protein and glucose concentrations and Pandy's test for CSF globulin) obtained on admission and sequentially from weekly follow-up lumbar punctures for 4 weeks were evaluated in 99 children (median age 28 months) with stage II (50 children) and stage III (49 children) tuberculous meningitis. On admission, six children (6%) had a CSF cell count greater than 500 x 10(6)/l and nine (9%) a polymorphonuclear predominance. A CSF protein less than 0.8 g/l was found in 17 children (18%) of 97 in whom CSF protein was evaluated. Globulin was either absent or present as a trace only in 26 children (27%). CSF glucose was less than 2.2 mmol/l in 58 cases (60%) and less than 2.5 mmol/l in 67 (69%). In 63 children weekly CSF specimens obtained for the 1st 4 weeks of therapy showed an uninterrupted decline in cell count in 23 (37%), a fluctuating downward trend in 27 (43%) and a fluctuating upward trend in 13 (21%). Sequential CSF protein values in 57 children showed an uninterrupted rise in three (5%), a fluctuating upward course in 19 (33%), an uninterrupted downward trend in seven (12%), and a fluctuating downward course in 28 (49%). Of the 61 children in whom sequential CSF glucose concentrations were available, 11 (18%) experienced fluctuating concentrations, values falling to less than 2.2 mmol/l after being greater than 2.2 mmol/l on admission or after having risen to greater than 2.2 mmol/l.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
64.
The data with which Student illustrated the application of his famous distribution are examined from a number of aspects. Central to the discussion is the within-patient clinical trial at Kalamazoo whose results were published by Cushny and Peebles and misquoted by Student and Fisher. This trial is discussed from historical, pharmacological and statistical perspectives. Student's and Fisher's analyses and a more modern analysis by Preece are considered as is Cushny's and Peebles's interpretation. Brief biographies of the five physicians involved in running the trial are presented. 相似文献
65.
66.
67.
Jonathan E. Bishop Giles E. Santyr Frederick Kelcz Donald B. Plewes 《Journal of magnetic resonance imaging : JMRI》1997,7(4):716-723
The effect of keyhole data acquisition on quantitative analysis of dynamic MRI was examined. Experiments were performed retrospectively on raw data obtained from clinical dynamic contrast-enhanced breast imaging procedures. The effects of keyhole phase-encoding acquisition and type of reconstruction algorithm on the accuracy of derived quantitative parameters was assessed. Results indicate that the minimum keyhole size used should be restricted by the approximate minimum size of the expected lesions. Furthermore, reconstruction algorithms that offer improved image resolution do not circumvent this restriction. 相似文献
68.
Malcolm E. Richardson Samuel Menahem James L. Wilkinson 《International journal of cardiology》1991,30(3):351-353
In this report, we give details of two families in which fixed subaortic stenosis was found in more than one member. It is rare for this entity to show familial incidence. 相似文献
69.
Laurie M. Lomasney John F. Madden Wagdy S. Rizk Lawrence W. Hedlund Salutorio Martinez Robert E. Coleman William J. Richardson H. Dirk Sostman 《Journal of magnetic resonance imaging : JMRI》1994,4(3):441-449
Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise. 相似文献
70.
Mark F. Cotton Peter R. Donald Johan F. Schoeman Lana E. Van Zyl Cor Aalbers Carl J. Lombard 《Child's nervous system》1993,9(1):10-15
Intracranial pressure (ICP) monitored shortly after admission over a period of 1 h in 31 children with tuberculous meningitis (TBM) was significantly higher (median 22.5 mm Hg, range 8.4–50.9 mmHg) in 19 children with laboratory evidence of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) than in 12 children without such evidence (median 16.2 mmHg, range 5.8–42.5 mmHg; P = 0.027). Neither plasma nor cerebrospinal fluid arginine vasopressin (AVP) was related to ICP (r = 0.33 and 0.13 respectively). Mean arterial pressure (MAP) was measured in 23 children and a moderate correlation was found with plasma AVP (r = 0.62; P = 0.0019). In TBM, plasma AVP may be secreted as a response to raised ICP in an effort to raise MAP and maintain cerebral perfusion pressure. In this setting excess fluid may be inappropriately retained, leading to hyponatremia and hypo-osmolemia. 相似文献