全文获取类型
收费全文 | 2933篇 |
免费 | 284篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 117篇 |
妇产科学 | 106篇 |
基础医学 | 520篇 |
口腔科学 | 62篇 |
临床医学 | 241篇 |
内科学 | 551篇 |
皮肤病学 | 83篇 |
神经病学 | 190篇 |
特种医学 | 240篇 |
外科学 | 390篇 |
综合类 | 88篇 |
一般理论 | 6篇 |
预防医学 | 306篇 |
眼科学 | 63篇 |
药学 | 156篇 |
中国医学 | 1篇 |
肿瘤学 | 99篇 |
出版年
2020年 | 25篇 |
2019年 | 29篇 |
2018年 | 32篇 |
2017年 | 37篇 |
2016年 | 24篇 |
2015年 | 49篇 |
2014年 | 44篇 |
2013年 | 83篇 |
2012年 | 109篇 |
2011年 | 97篇 |
2010年 | 72篇 |
2009年 | 75篇 |
2008年 | 104篇 |
2007年 | 112篇 |
2006年 | 88篇 |
2005年 | 97篇 |
2004年 | 96篇 |
2003年 | 98篇 |
2002年 | 91篇 |
2001年 | 100篇 |
2000年 | 108篇 |
1999年 | 88篇 |
1998年 | 53篇 |
1997年 | 75篇 |
1996年 | 66篇 |
1995年 | 57篇 |
1994年 | 43篇 |
1993年 | 25篇 |
1992年 | 66篇 |
1991年 | 64篇 |
1990年 | 90篇 |
1989年 | 68篇 |
1988年 | 63篇 |
1987年 | 71篇 |
1986年 | 90篇 |
1985年 | 63篇 |
1984年 | 48篇 |
1983年 | 48篇 |
1982年 | 35篇 |
1981年 | 32篇 |
1980年 | 38篇 |
1979年 | 65篇 |
1978年 | 48篇 |
1977年 | 45篇 |
1976年 | 27篇 |
1975年 | 27篇 |
1974年 | 30篇 |
1972年 | 24篇 |
1971年 | 22篇 |
1969年 | 26篇 |
排序方式: 共有3225条查询结果,搜索用时 15 毫秒
1.
2.
Identification of a Klebsiella pneumoniae strain associated with nosocomial urinary tract infection. 下载免费PDF全文
K S Kil R O Darouiche R A Hull M D Mansouri D M Musher 《Journal of clinical microbiology》1997,35(9):2370-2374
To differentiate between relapse of infection and reinfection of the urinary tract due to Klebsiella pneumoniae, 33 K. pneumoniae isolates collected from 20 patients with spinal cord injury (SCI) over 2 years were typed by genomic fingerprinting by repetitive-element PCR. Clinical isolates obtained from the same patients with recurrent episodes of urinary tract infection (UTI) revealed identical genomic fingerprints indicating relapse of UTI due to K. pneumoniae, despite appropriate antibiotic therapy. Seventeen isolates obtained from 8 of the 20 SCI patients shared a common genotype, termed RD6. Among non-SCI patients residing in other nursing units, the RD6 genotype was found in 5 of 10 patients with K. pneumoniae UTI but in only 1 of 20 patients with K. pneumoniae infection that did not involve the urinary tract, suggesting a strong association of this genotype with UTI. All RD6 isolates exhibited strong adherence (> or =50 adherent bacteria per cell) to HEp-2 cells, whereas other K. pneumoniae isolates generally did not adhere to or adhered very weakly to HEp-2 cells (< or =5 adherent bacteria per cell). Adherence was inhibited either by 4% D-mannose or by anti-type 1 fimbrial rabbit serum. These results suggest that the capacity of K. pneumoniae RD6 isolates to cause UTI may be mediated by its striking adherence to mammalian cells. 相似文献
3.
4.
5.
6.
M. S. Levine A. M. Adinolfi R. S. Fisher C. D. Hull D. Guthrie N. A. Buchwald 《Brain research》1988,440(2):267-279
These studies provide information on the changes in the ultrastructure in the caudate nucleus of aged cats. The major findings was that there was a decrease in the density of synapses in caudate neuropil. This decrease occurred in animals after 3 years of age and remained relatively constant in older animals. In conjunction with this change a population of unusually long synapses also occurred. These larger synaptic appositions were associated with enlarged spine heads. The caudate also showed a number of qualitative ultrastructural alterations. Many neurons contained accumulations of lipofuscin or lipopigment granules in aged animals. These inclusions occurred in both soma and dendrites of neurons and all types of glial cells. A unique configuration of collapsed agranular cisterns also was observed in aged animals. The present results indicate that decreases in synaptic density may by one morphological event underlying functional alterations observed in caudate neurons in aged cats. 相似文献
7.
Does changing from mercury to electronic blood pressure measurement influence recorded blood pressure? An observational study. 下载免费PDF全文
Richard J McManus Jonathan Mant Martyn R P Hull F D Richard Hobbs 《The British journal of general practice》2003,53(497):953-956
Mercury sphygmomanometers have been commonly used in primary care to measure blood pressure but are associated with bias. Electronic blood pressure machines are being introduced in many practices and have anecdotally been associated with higher recorded blood pressure. This study examined recorded blood pressure in four practices before and after electronic blood pressure machine introduction. No consistent change in mean blood pressure was apparent following their introduction, but there was a large and significant fall in terminal digit preference suggesting improved precision of recording. 相似文献
8.
Cleveland Clinic Lerner College of Medicine (CCLCM) is an innovative, five-year medical education track within Case Western Reserve University School of Medicine (Case) with a focused mission to attract and educate a limited number of highly qualified persons who seek to become physician investigators. CCLCM curriculum governance, faculty appointments and promotions, and admissions committees are integrated with respective Case committees. The CCLCM curriculum is based on faculty-defined professional attributes that graduates are expected to develop. These attributes were used to create curricular and assessment principles that guided the development of an integrated basic science, clinical science, and research curriculum, conducted in an active learning environment. An organ-system approach is used to solidify an understanding of basic science discipline threads in the context of relevant clinical problems presented in PBL and case-based discussion formats. Clinical skills are introduced in the first year as part of the two-year longitudinal experience with a family practice or internal medicine physician. The research program provides all students with opportunities to learn and experience basic and translational research and clinical research before selecting a research topic for their 12- to 15-month master-level thesis project. All Case students participate in required and elective clinical curriculum after the second year, but CCLCM students return to the Cleveland Clinic on selected Friday afternoons for program-specific research and professionalism-learning activities. A unique portfolio-based assessment system is used to assess student achievements in nine competency areas, seven of which reflect the Accreditation Council for Graduate Medical Education competencies. 相似文献
9.
10.
We have developed a computerized neuromuscular monitoring system (NMMS) using commercially available subsystems, i.e., computer
equipment, clinical nerve stimulator, force transducer, and strip-chart recorder. This NMMS was developed for acquisition
and analysis of data for research and teaching purposes. Computer analysis of the muscle response to stimulation allows graphic
and numeric presentation of the twitch response and calculated ratios. Since the system can store and recall data, research
data can be accessed for analysis and graphic presentation. An IBM PC/AT computer is used as the central controller and data
processor. The computer controls timing of the nerve stimulator output, initiates data acquisition, and adjusts the paper
speed of the strip chart recorder. The data processing functions include establishing control response values (when no neuromuscular
blockade is present), displaying force versus time and calculated data graphically and numerically, and storing these data
for further analysis. The general purpose nature of the computer and strip chart recording equipment allow modification of
the system primarily by changes in software. For example, new patterns of nerve stimulation, such as the posttetanic count,
can be programmed into the computer system along with appropriate data display and analysis routines. The NMMS has functioned
well in the operating room environment. We have had no episodes of electrocautery interference with the computer functions.
The automated features have enhanced the utility of the NMMS. The prime advantages of this system are (1) the ability to customize
its features by altering its controlling programs, (2) the ready availability of the hardware and software, (3) the general
purpose nature of the system, so that it is not limited to this one application, and (4) the adaptable nature of the system. 相似文献