全文获取类型
收费全文 | 10303篇 |
免费 | 1318篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 123篇 |
儿科学 | 390篇 |
妇产科学 | 337篇 |
基础医学 | 1588篇 |
口腔科学 | 189篇 |
临床医学 | 1390篇 |
内科学 | 1854篇 |
皮肤病学 | 211篇 |
神经病学 | 1195篇 |
特种医学 | 430篇 |
外科学 | 1185篇 |
综合类 | 269篇 |
一般理论 | 10篇 |
预防医学 | 991篇 |
眼科学 | 225篇 |
药学 | 757篇 |
中国医学 | 8篇 |
肿瘤学 | 493篇 |
出版年
2021年 | 121篇 |
2020年 | 97篇 |
2019年 | 154篇 |
2018年 | 174篇 |
2017年 | 152篇 |
2016年 | 127篇 |
2015年 | 150篇 |
2014年 | 232篇 |
2013年 | 310篇 |
2012年 | 428篇 |
2011年 | 423篇 |
2010年 | 269篇 |
2009年 | 225篇 |
2008年 | 390篇 |
2007年 | 432篇 |
2006年 | 433篇 |
2005年 | 438篇 |
2004年 | 411篇 |
2003年 | 385篇 |
2002年 | 335篇 |
2001年 | 368篇 |
2000年 | 370篇 |
1999年 | 310篇 |
1998年 | 154篇 |
1997年 | 156篇 |
1996年 | 124篇 |
1995年 | 136篇 |
1994年 | 103篇 |
1993年 | 106篇 |
1992年 | 227篇 |
1991年 | 225篇 |
1990年 | 227篇 |
1989年 | 232篇 |
1988年 | 251篇 |
1987年 | 242篇 |
1986年 | 227篇 |
1985年 | 181篇 |
1984年 | 133篇 |
1983年 | 144篇 |
1982年 | 116篇 |
1981年 | 107篇 |
1980年 | 103篇 |
1979年 | 149篇 |
1978年 | 127篇 |
1977年 | 93篇 |
1976年 | 115篇 |
1975年 | 106篇 |
1974年 | 119篇 |
1973年 | 102篇 |
1971年 | 101篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
Distraction osteogenesis in the Cbfa-1+/- mouse. 总被引:2,自引:0,他引:2
S Isefuku C J Joyner A A C Reed A H R W Simpson 《Journal of orthopaedic research》2004,22(6):1276-1282
54.
OBJECTIVE--To describe the characteristics of wheeze and its relation with doctor diagnosed asthma in children aged 5 years and under. DESIGN--Questionnaire survey of population based random sample of children registered on Leicestershire Health Authority's child health index for immunisation; questionnaire completed by parents. SUBJECTS--1650 white children born in 1985 to 1989 who were surveyed in 1990. MAIN OUTCOME MEASURES--Age distribution, severity, precipitants, seasonal characteristics, and diurnal variation of wheeze, family history of asthma/atopy, and their association(s) with doctor diagnosed asthma. RESULTS--There were 1422 replies (86.2%). Two hundred and twenty two (15.6%) were reported to have wheezed and of these 121 (8.6%) had formally been diagnosed as having asthma. More than 80% of the former had recurrences of wheeze and 40% (72) had three or more episodes in the preceding 12 months. Age, number of episodes per year, the severity of shortness of breath with attacks, and precipitants other than colds were the major factors determining the probability that a wheezy child will be diagnosed as having asthma. The data also suggest that despite the strong association of symptom based criteria with the label asthma, asthma was not diagnosed by these same severity criteria in one quarter of cases. CONCLUSIONS--Clinical and physiological follow up studies of children identified as asthmatic by the above criteria during the preschool years should validate or refute the predictive value of these measures of wheeze severity. 相似文献
55.
56.
57.
L Hoffman-Goetz B MacNeil Y Arumugam J Randall Simpson 《International journal of sports medicine》1992,13(2):167-171
Acute exercise and exercise conditioning have been shown to affect the activity of natural killer (NK) cells as well as the growth of experimentally induced tumors in animals. Since psychosocial factors are also known to alter NK activity and tumor growth, isolation, a known psychosocial stressor of mice, was also investigated to see if housing condition could alter exercise-induced changes in NK cell activity and tumor growth. NK cell activity and concentration of asialo GM1 (ASGM1) positive splenocytes were measured in male C3H mice inoculated i.v. with CIRAS 3 tumor cells. Mice were housed individually or in groups of four and trained to run for eight weeks on a rodent treadmill; controls remained sedentary throughout the experimental period. At four weeks into the training protocol, mice were injected with the tumor cells and continued to run for four weeks after tumor exposure. There was a significant effect of physical activity (p less than 0.019) but not of housing on splenic NK cytotoxicity against tumor targets in vitro. When the data were analyzed by presence or absence of lung metastases, only those animals without visible lung tumors had significantly higher NK activity as a function of exercise relative to sedentary controls. There were no significant differences in the frequency of ASGM1+ splenocytes between trained and untrained animals, irrespective of presence or absence of lung tumor colonies. There was a significant effect of housing (p less than 0.02), but not of physical activity, in mice with successful tumor takes with greater numbers of group housed animals (29/59) with tumor relative to individually housed animals (13/60).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
58.
Yoshimitsu Kuroyanagi DR. ENG DR. SCI DR. MED ; Akihiko Shiraishi MD ; Yoshiteru Shirasaki MD ; Nobuaki Nakakita MD ; Yoshiaki Yasutomi MD ; Yasuo Takano MD ; Nobuyuki Shioya MD FACS 《Wound repair and regeneration》1994,2(2):122-129
A bilaminar wound dressing composed of an outer membrane and an inner three-dimensional matrix of a fabric or a sponge may be considered to constitute an ideal structure that promotes wound healing: the outer membrane prevents body fluid loss, controls water evaporation, and protects the wound surface from bacterial invasion, and the inner matrix encourages adherence by tissue growth into the matrix. Using this concept, we developed a biosynthetic wound dressing with a drug delivery capability. This medicated wound dressing is composed of a spongy sheet of a chitosane derivative and collagen mixture that is laminated to an antimicrobial-impregnated polyurethane membrane. In this study, a gentamycin sulfate-impregnated wound dressing was prepared and evaluated. The antimicrobial efficacy of this wound dressing was examined on an agar plate seeded with Pseudomonas aeruginosa. Also, the cytotoxicity of an antimicrobial released from this wound dressing was examined in an in vitro system with cultured skin substitutes. Both in vitro tests have shown that this wound dressing is capable of suppressing bacterial growth and minimizing cellular damage. In addition, in the treatment of wounds inflicted on rats and rabbits, this wound dressing was shown to be efficacious in covering full-thickness and split-thickness skin defects. Finally, the efficacy of this wound dressing was evaluated in a nonrandomized open-label study of 31 clinical cases. In 31 cases treated with this wound dressing, good or excellent wound healing was achieved. 相似文献
59.
60.
DR Foster 《Journal of Medical Imaging and Radiation Oncology》1995,39(4):399-400
The use of self-expanding prostheses in the management of malignant oesophageal strictures has become well established. The majority of benign peptic oesophageal strictures can be successfully managed using endoscopic or fluoroscopically guided balloon oesophageal dilatation combined with long-term drug therapy, particularly using proton pumper inhibitors. Although endoscopic oesophageal dilatation can be performed on an outpatient basis, it requires repeated hospital visits. There is a small risk of oesophageal perforation whilst cardio-respiratory complications may be encountered during the use of intravenous sedation in an elderly population. The use of a self-expanding Strecker stent in a 98 year old woman with a benign oesophageal stricture is described. 相似文献