全文获取类型
收费全文 | 514287篇 |
免费 | 33280篇 |
国内免费 | 613篇 |
专业分类
耳鼻咽喉 | 6894篇 |
儿科学 | 16843篇 |
妇产科学 | 13535篇 |
基础医学 | 85060篇 |
口腔科学 | 14480篇 |
临床医学 | 44352篇 |
内科学 | 93673篇 |
皮肤病学 | 12158篇 |
神经病学 | 36197篇 |
特种医学 | 18456篇 |
外国民族医学 | 63篇 |
外科学 | 77063篇 |
综合类 | 8477篇 |
一般理论 | 118篇 |
预防医学 | 38983篇 |
眼科学 | 12138篇 |
药学 | 40542篇 |
中国医学 | 1007篇 |
肿瘤学 | 28141篇 |
出版年
2018年 | 4936篇 |
2015年 | 4516篇 |
2014年 | 6074篇 |
2013年 | 9561篇 |
2012年 | 12889篇 |
2011年 | 14293篇 |
2010年 | 8310篇 |
2009年 | 7778篇 |
2008年 | 13708篇 |
2007年 | 14705篇 |
2006年 | 14948篇 |
2005年 | 14358篇 |
2004年 | 14049篇 |
2003年 | 13395篇 |
2002年 | 13275篇 |
2001年 | 24070篇 |
2000年 | 25081篇 |
1999年 | 20560篇 |
1998年 | 5426篇 |
1997年 | 4706篇 |
1996年 | 5043篇 |
1995年 | 4626篇 |
1994年 | 4318篇 |
1993年 | 4136篇 |
1992年 | 15730篇 |
1991年 | 16311篇 |
1990年 | 16425篇 |
1989年 | 15799篇 |
1988年 | 14580篇 |
1987年 | 14423篇 |
1986年 | 13599篇 |
1985年 | 12978篇 |
1984年 | 9628篇 |
1983年 | 8249篇 |
1982年 | 4560篇 |
1981年 | 4229篇 |
1979年 | 9419篇 |
1978年 | 6855篇 |
1977年 | 5774篇 |
1976年 | 5608篇 |
1975年 | 6400篇 |
1974年 | 7634篇 |
1973年 | 7132篇 |
1972年 | 6960篇 |
1971年 | 6685篇 |
1970年 | 6173篇 |
1969年 | 5889篇 |
1968年 | 5559篇 |
1967年 | 5012篇 |
1966年 | 4451篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
153.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy. 相似文献
154.
155.
B. Bogin P. Smith A.B. Orden M.I. Varela Silva J. Loucky 《American journal of human biology》2002,14(6):753-761
Maya families from Guatemala migrated to the United States in record numbers from the late 1970s to the early 1990s. Births to Maya immigrant women have created a sizable number of Maya American children. The height and sitting height of 5 to 12 years children (n = 431) were measured in 1999 and 2000. Leg length was estimated and the sitting height ratio was calculated. These data were compared with a sample of Maya children living in Guatemala measured in 1998 (n = 1,347). Maya American children are currently 11.54 cm taller and 6.83 cm longer‐legged, on average, than Maya children living in Guatemala. Consequently, the Maya Americans have a significantly lower average sitting height ratio (i.e., relatively longer legs in proportion to length of the head and trunk) than do the Maya in Guatemala. These results add support to the hypothesis that both the height and body proportions of human populations are sensitive indicators of the quality of the environment for growth. Am. J. Hum. Biol. 14:753–761, 2002. © 2002 Wiley‐Liss, Inc. 相似文献
156.
BACKGROUND: Levels of an immunoregulatory and anti-inflammatory cytokine IL-10 are reduced in asthmatic airways, potentially contributing to more intense inflammation. Triamcinolone has anti-inflammatory properties and the anti-inflammatory effects of montelukast and formoterol have been discussed. OBJECTIVE: The purpose of this study was to define the effect of treatment with triamcinolone, montelukast and formoterol on the serum level of IL-10, eosinophil blood counts, eosinophil cationic response (ECP) and clinical parameters (symptom score, FEV1 and PC20H) in children with moderate asthma. METHODS: An 8-week, placebo-controlled and randomized, double-blind trial was carried out. The subjects were 91 children with moderate atopic asthma who were allergic to dust mite. Patients were randomly allocated to receive 400 microg triamcinolone (n = 19), 5 or 10 mg (according to age) montelukast (n = 18), 24 microg formoterol (n = 18) or placebo (n = 36). RESULTS: Seventy-nine children completed the study. After treatment with triamcinolone and montelukast the level of IL-10 in blood serum significantly increased, eosinophil blood counts and ECP levels significantly decreased and all clinical parameters improved; treatment with formoterol had no effect on IL-10 level, eosinophil blood counts in serum and bronchial hyper-reactivity; ECP level significantly decreased after treatment and asthma symptoms and FEV1 improved significantly. Mean IL-10 levels in serum before and after treatment with triamcinolone were 7.23 pg/mL with 95% CI, 6.74 -7.72% and 14.24 pg/mL with 95% CI, 11.6-16.88%, respectively (P < 0.001); with montelukast they were 6.59 pg/mL with 95% CI, 6.26-7.23% and 10.94 pg/mL with 95% CI, 8.24-12.65%, respectively (P < 0.002); with formoterol they were 7.06 pg/mL with 95% CI, 6.61-7.52% and 7.04 pg/mL with 95% CI, 6.15-7.93%. We found statistically significant correlations between serum level of IL-10 and serum level of ECP after treatment with triamcinolone and montelukast. CONCLUSION: This study demonstrates that one possible way by which triamcinolone and montelukast contribute to inhibition of inflammation is by increasing IL-10 levels. 相似文献
157.
158.
Anal dilatation is still used in the treatment of anal fissure and haemorrhoids. Using anorectal physiology and anal endosonography we have studied 12 men presenting with faecal incontinence following anal dilatation. Resting anal pressures were low, pudendal nerve latencies were normal; 11 men had a disrupted internal anal sphincter and in ten this was extensively fragmented. Three also had defects of the external anal sphincter. These findings demonstrate for the first time the nature of the structural injury which may be caused by anal dilatation. 相似文献
159.
160.