全文获取类型
收费全文 | 1629篇 |
免费 | 112篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 48篇 |
妇产科学 | 69篇 |
基础医学 | 214篇 |
口腔科学 | 47篇 |
临床医学 | 163篇 |
内科学 | 347篇 |
皮肤病学 | 23篇 |
神经病学 | 116篇 |
特种医学 | 136篇 |
外科学 | 223篇 |
综合类 | 66篇 |
预防医学 | 159篇 |
眼科学 | 17篇 |
药学 | 87篇 |
中国医学 | 2篇 |
肿瘤学 | 42篇 |
出版年
2022年 | 15篇 |
2021年 | 23篇 |
2019年 | 28篇 |
2018年 | 34篇 |
2017年 | 27篇 |
2016年 | 24篇 |
2015年 | 34篇 |
2014年 | 31篇 |
2013年 | 49篇 |
2012年 | 49篇 |
2011年 | 58篇 |
2010年 | 52篇 |
2009年 | 49篇 |
2008年 | 42篇 |
2007年 | 68篇 |
2006年 | 73篇 |
2005年 | 63篇 |
2004年 | 63篇 |
2003年 | 53篇 |
2002年 | 55篇 |
2001年 | 44篇 |
2000年 | 50篇 |
1999年 | 33篇 |
1998年 | 38篇 |
1997年 | 42篇 |
1996年 | 55篇 |
1995年 | 29篇 |
1994年 | 18篇 |
1993年 | 28篇 |
1992年 | 34篇 |
1991年 | 29篇 |
1990年 | 20篇 |
1989年 | 33篇 |
1988年 | 24篇 |
1987年 | 30篇 |
1986年 | 34篇 |
1985年 | 26篇 |
1984年 | 24篇 |
1983年 | 17篇 |
1981年 | 13篇 |
1980年 | 19篇 |
1979年 | 27篇 |
1978年 | 15篇 |
1977年 | 17篇 |
1976年 | 20篇 |
1975年 | 18篇 |
1974年 | 18篇 |
1973年 | 17篇 |
1970年 | 14篇 |
1967年 | 11篇 |
排序方式: 共有1764条查询结果,搜索用时 15 毫秒
1.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
2.
B I Sparks 《Journal of the American Optometric Association》1990,61(6):471-473
The purpose of the study was to determine if optometry students who completed an externship at a military facility were influenced for or against future enlistment considerations. The responses of 62 students were evaluated over a period of 3 years using an original self-completion questionnaire. The results suggest that while the majority of students left their externship with a positive attitude toward the military practice of optometry, factors such as low salaries and lagging promotional considerations influenced most to overlook the military as a practice option. The important ramifications of the study, as well as potential threats to its validity, are discussed. 相似文献
3.
Andrew G. Sparks Hsi-Han Yeh Siva S. Banda 《Optimal control applications & methods.》1990,11(4):307-325
This paper introduces a design methodology for a dynamic compensator that simultaneously minimizes the upper bound of a quadratic performance index and the H∞-norm of a disturbance transfer function matrix of a multiple-input/multiple-output system whose model contains parameter uncertainty in the state and input matrices. The real parameter uncertainty is modelled as additional measurement outputs and as additional weights on the existing noise inputs and measurement outputs of the system. The compensator equations are derived by taking the dual of a system with parameter variation in the state and output matrices, for which the compensator equations have previously been derived, and then taking the dual of the compensator equations. An algorithm for applying this theory is given and an example is shown. 相似文献
4.
5.
6.
7.
Use of triple-lumen subclavian catheters for administration of total parenteral nutrition. 总被引:1,自引:0,他引:1
N Clark-Christoff V A Watters W Sparks P Snyder J P Grant 《JPEN. Journal of parenteral and enteral nutrition》1992,16(5):403-407
This study evaluated the safety of triple vs single-lumen catheters in intravenous nutrition. Patients who were judged likely to benefit from a triple-lumen catheter were randomized to receive either a single-lumen catheter, with additional peripheral or central venous access as needed, or a triple-lumen catheter. All patients were at increased risk of catheter-related infection because of one or more of the following conditions: > 60 years of age, breakdown of skin integrity, severe underlying illness, diagnosis of acute pancreatitis, recent head or neck surgery, or presence of a preexisting infection. Patients were excluded who had neutropenia, were immunosuppressed, had body burns > 40%, or had contaminated wounds in the subclavicular area. Of 204 patients entered between June 1989 and November 1991, 177 completed the required > or = 7 days of therapy. Seventy-eight of these patients were randomized to a single-lumen catheter and 99 to a triple-lumen catheter. Catheters were inserted and maintained by the Nutrition Support Team. Dressings were monitored daily and changed weekly using a bio-occlusive dressing. When parameters were met for a possible septic episode, simultaneous peripheral and central catheter blood cultures were obtained using the Isolator method. Catheter-related sepsis was considered present if the colony count from a central catheter lumen was > or = 5 times that of the peripheral blood. The incidence of catheter-related sepsis for single-lumen catheters was 2.6% (2 of 78) compared with 13.1% for triple-lumen catheters (13 of 99) (p < .01). No correlation was found with the number of insertion attempts, catheter days, or patient's age.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
8.
9.
Laurie Sparks PhD RN CPNP Madeleine Rush Ortman MSN RN PCNS Pamela Aubuchon BS CCLS 《Journal of Orthopaedic Nursing》2004,8(4):206
Caring for a child in a body cast is a stressful situation for most families and many families state they do not receive adequate information on how to care for their child. This paper presents a comprehensive guide on caring for a child in a body cast. It examines the physical care issues, transportation and cast care. An instrument for assessing the family’s ability to cope with caring for a child in a body cast is described, and further resources for parents and nurses are presented. 相似文献
10.
Genotype-phenotype correlation for nucleotide substitutions in the IgII- IgIII linker of FGFR2 总被引:6,自引:3,他引:3