全文获取类型
收费全文 | 1599篇 |
免费 | 84篇 |
国内免费 | 114篇 |
专业分类
儿科学 | 71篇 |
妇产科学 | 55篇 |
基础医学 | 199篇 |
口腔科学 | 34篇 |
临床医学 | 182篇 |
内科学 | 363篇 |
皮肤病学 | 39篇 |
神经病学 | 84篇 |
特种医学 | 396篇 |
外国民族医学 | 1篇 |
外科学 | 61篇 |
综合类 | 47篇 |
预防医学 | 100篇 |
眼科学 | 12篇 |
药学 | 86篇 |
中国医学 | 1篇 |
肿瘤学 | 66篇 |
出版年
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 14篇 |
2020年 | 7篇 |
2019年 | 16篇 |
2018年 | 19篇 |
2017年 | 4篇 |
2016年 | 23篇 |
2015年 | 30篇 |
2014年 | 34篇 |
2013年 | 52篇 |
2012年 | 23篇 |
2011年 | 38篇 |
2010年 | 54篇 |
2009年 | 56篇 |
2008年 | 39篇 |
2007年 | 72篇 |
2006年 | 58篇 |
2005年 | 66篇 |
2004年 | 28篇 |
2003年 | 29篇 |
2002年 | 23篇 |
2001年 | 25篇 |
2000年 | 38篇 |
1999年 | 24篇 |
1998年 | 95篇 |
1997年 | 97篇 |
1996年 | 105篇 |
1995年 | 65篇 |
1994年 | 62篇 |
1993年 | 65篇 |
1992年 | 11篇 |
1991年 | 35篇 |
1990年 | 25篇 |
1989年 | 49篇 |
1988年 | 38篇 |
1987年 | 52篇 |
1986年 | 36篇 |
1985年 | 49篇 |
1984年 | 21篇 |
1983年 | 18篇 |
1982年 | 30篇 |
1981年 | 20篇 |
1980年 | 32篇 |
1979年 | 12篇 |
1978年 | 12篇 |
1977年 | 18篇 |
1976年 | 28篇 |
1975年 | 15篇 |
1969年 | 3篇 |
排序方式: 共有1797条查询结果,搜索用时 656 毫秒
941.
Molecular heterogeneity of glucose-6-phosphate dehydrogenase A- 总被引:9,自引:0,他引:9
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is probably the most common disease-producing genetic polymorphism of humans. Virtually all G6PD-deficient Africans show the G6PD A- phenotype, an electrophoretically rapid, deficient enzyme. The recently acquired ability to identify the point mutations producing the different variants has given us new insights into the population genetics of G6PD variants. Twenty-nine males with the G6PD A- phenotype were studied. They were of African, Mexican, Spanish, and US white ethnic origin. All had the A---G transition at nucleotide 376 characteristic of G6PD A. In each case, one of three additional mutations was present, at nucleotides 202, 680, or 968. That in this population second mutations producing G6PD deficiency occurred only on the genetic background of G6PD A suggests that G6PD A was at one time the most common type of G6PD in Africa. However, the nucleotide sequence of the chimpanzee (Pan troglodytes) G6PD indicates that the primordial human type of G6PD was G6PD B. 相似文献
942.
To examine the hypothesis that the increased adrenocortical activity during lactation induced the loss of the prolactin (PRL) -releasing effect of morphine, we studied the effect of morphine in adrenalectomized (ADX) and sham-operated primiparous lactating Wistar rats. Animals were adrenalectomized 4 days after delivery. On day 11 of lactation (7 days after ADX), pups were separated from their mother 2 h before morphine or haloperidol injection. Intravenous injection of 5 mg/kg morphine did not change plasma PRL levels in the sham-operated lactating rats, but it resulted in a significant increase of plasma PRL levels in ADX lactating animals, with or without corticosterone replacement. Catalepsy following 10 mg/kg i.v. morphine was also markedly enhanced in ADX lactating animals. The PRL response to 0.5 mg/kg haloperidol was higher in ADX lactating animals than that in the controls. Morphine given 2 h after haloperidol treatment resulted in a further increase of plasma PRL in ADX, but not in the sham-operated lactating animals. These results suggest that adrenal hyperfunction may lead to a loss of sensitivity to morphine during lactation. 相似文献
943.
Rotator cuff impingement syndrome: MR imaging 总被引:2,自引:0,他引:2
944.
945.
946.
Primary lesions of bone in the 1st decade of life: retrospective survey of biopsy results 总被引:1,自引:0,他引:1
Primary bone tumors in early childhood are uncommon, and the incidence of malignancy in the 1st decade of life has not been evaluated adequately in the literature. For this reason, we conducted a retrospective review of 268 biopsies of the bone in 249 patients who were less than 10 years of age. Benign tumors were found much more frequently than malignant lesions. Osteochondroma and histiocytosis X were the most common lesions. The incidence of several benign lesions in our series was deceptively low, as many lesions showed typical radiographic findings, precluding the need for biopsy or excision. Of 41 primary malignant bone tumors, Ewing sarcoma was slightly more common than osteosarcoma. The rib was the most frequent site of the former; the distal femur, of the latter. 相似文献
947.
948.
949.
950.
Summary In soil, the herbicide methyl-N-(3,4-dichlorophenyl)-carbamate (Swep) was transformed to 3,4-dichloroaniline, 3,3,4, 4-tetrachloroazobenzene and other unidentified compounds. The rate of Swep degradation was found to be slower than that of acylanilide herbicides. Under identical conditions 3-(3,4-dichlorophenyl)-1, 1-dimethylurea (Diuron) and 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (Linuron) remained unchanged for 40 days.This paper of the Journal Series, New Jersey Agricultural Experiment Station was supported in part by USPHS research grant ES-16. 相似文献