全文获取类型
收费全文 | 17111篇 |
免费 | 1416篇 |
国内免费 | 7篇 |
出版年
2024年 | 12篇 |
2023年 | 118篇 |
2022年 | 271篇 |
2021年 | 533篇 |
2020年 | 309篇 |
2019年 | 399篇 |
2018年 | 457篇 |
2017年 | 352篇 |
2016年 | 662篇 |
2015年 | 1073篇 |
2014年 | 1159篇 |
2013年 | 1344篇 |
2012年 | 1627篇 |
2011年 | 1456篇 |
2010年 | 929篇 |
2009年 | 773篇 |
2008年 | 1019篇 |
2007年 | 995篇 |
2006年 | 886篇 |
2005年 | 807篇 |
2004年 | 772篇 |
2003年 | 617篇 |
2002年 | 617篇 |
2001年 | 105篇 |
2000年 | 90篇 |
1999年 | 110篇 |
1998年 | 125篇 |
1997年 | 96篇 |
1996年 | 90篇 |
1995年 | 65篇 |
1994年 | 60篇 |
1993年 | 49篇 |
1992年 | 48篇 |
1991年 | 38篇 |
1990年 | 37篇 |
1989年 | 48篇 |
1988年 | 38篇 |
1987年 | 24篇 |
1986年 | 20篇 |
1985年 | 28篇 |
1984年 | 30篇 |
1983年 | 22篇 |
1982年 | 19篇 |
1981年 | 18篇 |
1980年 | 21篇 |
1979年 | 19篇 |
1978年 | 13篇 |
1976年 | 17篇 |
1974年 | 13篇 |
1968年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
981.
A major research area concentrates on understanding the regulation of replication origin firing. It is now appreciated that checkpoint signaling participates in this controlled process and that defects in such signaling systems affect genome integrity. Inhibition of replication origin firing is most obviously apparent under conditions of replication stress, but origin firing must also be regulated on a minute-by-minute basis as cells progress normally through an unabated S-phase. Here we summarize a straightforward model to account for how origin firing could be controlled by a self-regulating system. 相似文献
982.
983.
The way we think about and care for people with developmental disability has changed. Twenty-five years ago, society believed that caregivers always knew what was best for their individual and that he or she must be shielded, even shut away from, the harms that could occur in society. Now, people with disability participate in all aspects of community life. They are educated in local schools, live at home or in their own home, and compete with others in the job market. Caregiving for people with developmental disability is no longer modeled on medicine or stigmatizing labels. Instead, caregivers have become support persons who focus on identifying community resources and making the environment friendlier and safer for persons with disability. 相似文献
984.
985.
986.
Road map to metastasis 总被引:9,自引:0,他引:9
987.
988.
DNA analysis of the low-density lipoprotein receptor gene of a young Brazilian man, suffering from an extreme form of hypercholesterolemia, revealed the presence of two mutations, thereby confirming the diagnosis of homozygous familial hypercholesterolemia (FH). The first mutation was a mutation frequently found in Brazilian patients with FH, termed C660X or FHLebanese. The second mutation, in which a serine residue was replaced by a cysteine at amino acid position 305 (S305C) was a new mutation never described before. S305C was inherited from the proband's mother, who was of Italian descent. The occurrence of LDL receptor gene mutations of Lebanese and Italian origin in Brazil underlines the genetic heterogeneity of the Brazilian population. 相似文献
989.
990.