全文获取类型
收费全文 | 3438篇 |
免费 | 282篇 |
国内免费 | 31篇 |
出版年
2021年 | 23篇 |
2020年 | 25篇 |
2019年 | 28篇 |
2018年 | 37篇 |
2017年 | 32篇 |
2016年 | 57篇 |
2015年 | 109篇 |
2014年 | 119篇 |
2013年 | 146篇 |
2012年 | 182篇 |
2011年 | 205篇 |
2010年 | 133篇 |
2009年 | 135篇 |
2008年 | 183篇 |
2007年 | 212篇 |
2006年 | 153篇 |
2005年 | 160篇 |
2004年 | 162篇 |
2003年 | 175篇 |
2002年 | 175篇 |
2001年 | 48篇 |
2000年 | 27篇 |
1999年 | 51篇 |
1998年 | 50篇 |
1997年 | 21篇 |
1996年 | 35篇 |
1995年 | 37篇 |
1994年 | 32篇 |
1993年 | 39篇 |
1992年 | 28篇 |
1991年 | 36篇 |
1990年 | 24篇 |
1989年 | 34篇 |
1988年 | 32篇 |
1987年 | 30篇 |
1986年 | 26篇 |
1985年 | 34篇 |
1984年 | 32篇 |
1983年 | 36篇 |
1982年 | 37篇 |
1981年 | 37篇 |
1980年 | 35篇 |
1979年 | 28篇 |
1978年 | 39篇 |
1977年 | 24篇 |
1976年 | 19篇 |
1974年 | 27篇 |
1973年 | 49篇 |
1972年 | 19篇 |
1971年 | 26篇 |
排序方式: 共有3751条查询结果,搜索用时 46 毫秒
1.
Ghotas Evindar Sylvie G. Bernier Malcolm J. Kavarana Elisabeth Doyle Jeanine Lorusso Michael S. Kelley Keith Halley Amy Hutchings Albion D. Wright Ashis K. Saha Gerhard Hannig Barry A. Morgan William F. Westlin 《Bioorganic & medicinal chemistry letters》2009,19(2):369-372
In the design of potent and selective sphingosine-1-phosphate receptor agonists, we were able to identify two series of molecules based on phenylamide and phenylimidazole analogs of FTY-720. Several designed molecules in these scaffolds have demonstrated selectivity for S1P receptor subtype 1 versus 3 and excellent in vivo activity in mouse. Two molecules PPI-4621 (4b) and PPI-4691 (10a), demonstrated dose responsive lymphopenia, when administered orally. 相似文献
2.
Mark Andrews Alan Brown Jean-Yves Chiva David Fradet David Gordon Mark Lansdell Malcolm MacKenny 《Bioorganic & medicinal chemistry letters》2009,19(8):2329-2332
The reported selective serotonin Re-uptake Inhibitor Litoxetine was used as the starting point in the design of a range of potential SSRIs with high ease of synthetic accessibility. Preparation and subsequent optimization yielded a range of potent and highly selective SSRIs. 相似文献
3.
4.
Indol-3yl-acetic acid was identified in extracts of sterile roots of Zeamays seedlings by means of TLC, chromogenic reactions, GLC and GC-MS. 相似文献
5.
6.
Summary Ninety-nine cases of thyroxine binding globulin (TBG) deficiency (90 males and 9 females) were identified among low-T4 infants after newborn hypothyroid screening. The data indicate that inherited TBG deficiency occurs in at least 1: 5,000 newborns (1:2,800 males) and that mild and more pronounced forms are found in approximately equal proportions. Genetic analysis indicates that X-linked inheritance is the usual mode with no suggestion of autosomal inheritance. 相似文献
7.
8.
Glucagon and its receptors have been identified within the mammalian brain, and their anatomical distribution correlates well with the distribution of opioid peptides and their receptors. To evaluate possible physiological interactions between these two peptidergic systems, we examined the effects of glucagon on two opioid responses - bradycardia and antinociception. Glucagon administered either intravenously (iv) (100-1000 micrograms/kg) or intracerebroventricularly (icv) (5 micrograms) significantly attenuated morphine-induced (200 micrograms/kg, iv) bradycardia without producing any alterations in cardiovascular parameters when given alone. Furthermore, glucagon did not antagonize the bradycardia produced by phenyldiguanide (10 micrograms/kg, iv), a non-opioid substance. Peripheral (1 mg/kg, iv) and central (5 micrograms, icv) glucagon pretreatment antagonized morphine-induced (7.5 mg/kg, intraperitoneal) antinociception by 67% and 86%, respectively, at 30 minutes (as determined by the hot plate test). Glucagon treatment alone at these doses did not alter baseline response latencies. In both cases, central injections of glucagon were more effective than iv injections in antagonizing morphine's effects. These findings demonstrate a central action for glucagon and provide the first evidence that this neuropeptide may function as an endogenous antagonist of opioid actions. 相似文献
9.
10.
Jeffrey Pomerance Richard Johnson Shoba Kagal Philip Brooks Malcolm Margolin Arthur Allen 《The Western journal of medicine》1980,133(4):289-291
Recently, there has been increased interest in the influence of maternal prenatal nutrition on the course and outcome of pregnancy. Evidence has accumulated that a woman''s weight before pregnancy and the weight gained during pregnancy directly affect infant birth weight, incidence of neonatal mortality, and growth and development of the infant during the first year of life. Although recent recommendations for weight gain in pregnancy have been liberalized, a survey of 195 pregnant women who had prenatal visits in both clinic and private offices showed deficiencies in their understanding of the subject. Some 37 percent of women believed they should gain 20 pounds (9 kg) or less during pregnancy. Eight percent admitted to dieting before at least one antenatal visit and 54 percent thought their doctor would not be concerned about too little weight gained during pregnancy. This suggests that many women and some doctors are still ignorant of current concepts of proper nutrition during pregnancy. Apparently, increased lay and professional educational efforts are needed. 相似文献