全文获取类型
收费全文 | 333211篇 |
免费 | 39835篇 |
国内免费 | 224篇 |
出版年
2016年 | 3688篇 |
2015年 | 5685篇 |
2014年 | 6551篇 |
2013年 | 9152篇 |
2012年 | 10546篇 |
2011年 | 10588篇 |
2010年 | 7117篇 |
2009年 | 6672篇 |
2008年 | 9367篇 |
2007年 | 9680篇 |
2006年 | 9234篇 |
2005年 | 9103篇 |
2004年 | 8826篇 |
2003年 | 8800篇 |
2002年 | 8437篇 |
2001年 | 11510篇 |
2000年 | 11565篇 |
1999年 | 9719篇 |
1998年 | 4202篇 |
1997年 | 4190篇 |
1996年 | 4130篇 |
1995年 | 3830篇 |
1994年 | 3805篇 |
1993年 | 3816篇 |
1992年 | 8590篇 |
1991年 | 8332篇 |
1990年 | 8128篇 |
1989年 | 8034篇 |
1988年 | 7578篇 |
1987年 | 7492篇 |
1986年 | 6970篇 |
1985年 | 7141篇 |
1984年 | 6104篇 |
1983年 | 5453篇 |
1982年 | 4530篇 |
1981年 | 4365篇 |
1980年 | 3909篇 |
1979年 | 6202篇 |
1978年 | 4914篇 |
1977年 | 4703篇 |
1976年 | 4522篇 |
1975年 | 4768篇 |
1974年 | 5258篇 |
1973年 | 5155篇 |
1972年 | 4744篇 |
1971年 | 4257篇 |
1970年 | 3758篇 |
1969年 | 3793篇 |
1968年 | 3404篇 |
1967年 | 2917篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
941.
942.
943.
944.
945.
Fragility and spiralization anomalies of the chromosomes in three cases, including fraternal twins, with Fanconi's anemia, type Estren-Dameshek 总被引:3,自引:0,他引:3
Fraternal twins, offspring of consanguineous parents, developed pancytopenia, the boy at 7, the girl at 12 years of age. A third patient became anemic at 3 years. All three are free of associated malformations. In blood cultures the incidence of chromatid breaks, exchanges, and chromosome-type aberrations was elevated to 24%, 18%, and 28%, respectively. In addition, in a low number of mitotic cells unusual observations, pointing to profound disturbances of chromosome structure, were made. It is suggested that these patients have a genetic defect impairing the normal process of mitotic chromosome condensation and decondensation. 相似文献
946.
After 30 years of continuous research into the mechanisms of human hypertension, we summarize the results obtained by the members of the multidisciplinary research group on hypertension of the Clinical Research Institute of Montreal on the disturbances of minerlocorticoid activity in a rigorously selected group of patients with early, mild essential hypertension. We attempt to integrate these findings with those of many other groups working on other aspects of hypertensive cardiovascular diseases. On the assumption that the increased peripheral resistance responsible for hypertension results from an imbalance or a disturbance of the equilibrium between the sympathetic nervous system and norepinephrine on one hand, and the vascular tone, sensitivity and responsiveness of the arterial smooth muscle to norepinephrine and to angiotensin II on the other hand, three models that fit the experimental and clinical facts as known at present are described. 相似文献
947.
W. C. Barrett Jr. 《Biotechnic & histochemistry》1932,7(2):63-64
Heidenhain's hematoxylin, according to the following formula, may be used for studying chromosomes in temporary smears of pollen mother cells: 1 part 0.5% hematoxylin and 4% iron-alum (equal parts of each); 1 part 95% alcohol; and 2 parts glacial acetic acid. 相似文献
948.
949.
950.
Albinism and mouse behaviour 总被引:1,自引:0,他引:1