全文获取类型
收费全文 | 1000163篇 |
免费 | 75683篇 |
国内免费 | 2624篇 |
专业分类
耳鼻咽喉 | 13031篇 |
儿科学 | 34588篇 |
妇产科学 | 28581篇 |
基础医学 | 145760篇 |
口腔科学 | 27761篇 |
临床医学 | 90545篇 |
内科学 | 193884篇 |
皮肤病学 | 22989篇 |
神经病学 | 79229篇 |
特种医学 | 38632篇 |
外国民族医学 | 305篇 |
外科学 | 149996篇 |
综合类 | 23794篇 |
一般理论 | 386篇 |
预防医学 | 78030篇 |
眼科学 | 22708篇 |
药学 | 72096篇 |
3篇 | |
中国医学 | 2036篇 |
肿瘤学 | 54116篇 |
出版年
2018年 | 10602篇 |
2017年 | 8277篇 |
2016年 | 9418篇 |
2015年 | 10647篇 |
2014年 | 14498篇 |
2013年 | 22104篇 |
2012年 | 29105篇 |
2011年 | 30967篇 |
2010年 | 18588篇 |
2009年 | 17518篇 |
2008年 | 28937篇 |
2007年 | 30609篇 |
2006年 | 31089篇 |
2005年 | 29749篇 |
2004年 | 29018篇 |
2003年 | 27913篇 |
2002年 | 26911篇 |
2001年 | 47015篇 |
2000年 | 48129篇 |
1999年 | 40345篇 |
1998年 | 11208篇 |
1997年 | 10126篇 |
1996年 | 10192篇 |
1995年 | 9807篇 |
1994年 | 9130篇 |
1993年 | 8521篇 |
1992年 | 32313篇 |
1991年 | 31507篇 |
1990年 | 31064篇 |
1989年 | 29924篇 |
1988年 | 27204篇 |
1987年 | 27368篇 |
1986年 | 25471篇 |
1985年 | 24644篇 |
1984年 | 18433篇 |
1983年 | 15548篇 |
1982年 | 9321篇 |
1981年 | 8402篇 |
1979年 | 16908篇 |
1978年 | 12253篇 |
1977年 | 10339篇 |
1976年 | 9778篇 |
1975年 | 10194篇 |
1974年 | 12348篇 |
1973年 | 11867篇 |
1972年 | 10898篇 |
1971年 | 10131篇 |
1970年 | 9401篇 |
1969年 | 8750篇 |
1968年 | 8124篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
B A Sommerville C G Scanes R Swaminathan A D Care S Harvey A Chadwick 《General and comparative endocrinology》1989,76(2):261-266
An experiment was carried out to investigate the effect of a range of estradiol (E2) doses (0.1-6.5 micrograms/g body wt/day) on vitamin D metabolism and the plasma levels of growth hormone (GH) and prolactin (PRL) in the growing chick. Doses of 0.5-0.7 microgram/g E2, which are insufficient to raise the plasma calcium level, did induce an increase in growth rate, an increase in 25-hydroxyvitamin D 1 alpha-hydroxylase (1-hydroxylase) and 24-hydroxylase activities, and an increase in plasma GH level. These parameters leveled off or fell over the dose range 1-2 micrograms/g E2 but there was evidence of a second peak in 1-hydroxylase activity at 6 micrograms/g E2. At this high dose rate, the plasma Ca level rose to 8 mM, as it does in the laying hen; 24-hydroxylase activity, growth rate, and plasma GH and plasma PRL levels all decreased. It was concluded that the dose response to estrogen in the growing chick is not linear and, in the case of 1-hydroxylase activity, may even be biphasic. 相似文献
132.
Up to now two abnormal nephrographic patterns have been described as a result of arterial hypotension as an adverse response to urographic contrast material. We would like to describe a third pattern. 相似文献
133.
Perceptual asymmetry on a series of four specially constructed dichotic word tests was found to change as a function of the emotional quality of the words in the tests (P = 0.05). This was most pronounced in the case of positively valued words which produced an increase in asymmetry consistent with facilitated left-hemisphere function (P less than 0.004). Changes in asymmetry with emotion differed as a function of personality characteristics of the subjects, with repressors and high anxious subjects showing an increase with emotion while true low anxious subjects showed a decrease (P less than 0.02). Personality groups also differed in asymmetry on an emotionally neutral test (P less than 0.04) and in changes in asymmetry over time independent of emotion (P less than 0.001). These data suggest that emotion mediated activation of the left hemisphere may facilitate information processing within that hemisphere. Moreover, they indicate that dichotic listening tests may provide a non-invasive and inexpensive method for assessing emotion mediated changes in brain state that are clinically relevant. 相似文献
134.
135.
S B Wieslander B T Mortensen L Binderup N I Nissen 《European journal of haematology》1987,39(1):35-38
10 patients with CLL and 2 with CML were treated with gradually increasing doses of 1 alpha(OH)D3, up to 4 micrograms daily during 6 wk. 3 patients with preleukemia and 1 with myelofibrosis were treated with 2 micrograms daily of 1 alpha(OH)D3 for a prolonged period up to 17 wk. The treatment with 1 alpha (OH)D3 did not result in changes of disease parameters in any of the patients under study. Receptor studies for 1,25(OH)2D3 were performed in 8 CLL patients and revealed only 1 patient with increased specific receptor binding capacity. The maximum tolerable dose of 1 alpha(OH)D3 varied individually, but was in the range of 2-4 micrograms daily. 相似文献
136.
N Scopinaro E Gianetta D Friedman G F Adami E Traverso B Vitale M Castagnola G Semino M Summa V Bachi 《Gastroenterology Clinics of North America》1987,16(3):529-531
Biliopancreatic diversion is a very effective method for weight reduction. In some instances it is too effective and needs to be revised. 相似文献
137.
138.
139.
These researchers investigated the effects of a progressive resistive, cycle ergometric exercise program on cardio-vascular endurance in one rheumatoid arthritic. The 46 yr. old, male subject exercised three days/week for 14 weeks. Workouts included interval-type training using 5 minute intervals for a total of 20-30 minutes (work rate set at 50-75 watts for each interval), not including 3-minute warm-up and cool-down periods (work rate set at zero resistance). Maximal exercise stress testing on the cycle ergometer was completed and blood samples collected before and after the exercise program. Also, psychological and physical health and lifestyle data were gathered before, during and after completion of the program. The conditioning program produced a training effect (greater than 75% of the HR max after the second exercise session) and blood values improved (10-28%) from the beginning to the end of the program. Finally, the program appeared to have a positive influence on various physical and psychological parameters as perceived by the subject and his wife. 相似文献
140.