全文获取类型
收费全文 | 195篇 |
免费 | 20篇 |
国内免费 | 2篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 14篇 |
2014年 | 8篇 |
2013年 | 10篇 |
2012年 | 9篇 |
2011年 | 11篇 |
2010年 | 14篇 |
2009年 | 8篇 |
2008年 | 10篇 |
2007年 | 7篇 |
2006年 | 12篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有217条查询结果,搜索用时 31 毫秒
1.
A growth factor in bovine colostrum was purified to homogeneity by a combination of acid extraction, boiling, cation exchange chromatography, isoelectric focusing, and reverse phase HPLC. The bovine colostrum growth factor (BCGF) had an isoelectric point of about 10, a native mol wt of about 30,000, was resistant to inactivation by boiling and exposure to pH 1, but was inactivated by dithiothreitol. BCGF appeared to be structurally related to human platelet-derived growth factor (PDGF) and competed with human PDGF in a radioreceptor assay. However, while human PDGF appeared to be a heterodimer of 17,000 and 14,000 mol wt subunits, BCGF appeared to be a homodimer of 20,000 mol wt subunits. Purified BCGF had a specific activity in stimulating 3T3 cell proliferation of about 3-6 U/ng and was active at about 1-2 ng/ml. 相似文献
2.
Parietal yolk sac cells M1536-B3 grown on cytodex 2 beads deposited an extracellular matrix on the surface of the beads. Cell-free matrix-coated beads were isolated by treatment of the cell monolayer with cytochalasin B (CB) at a concentration of 10 μg/ml of phosphate-buffered saline (PBS). The matrix when analysed by electrophoresis on polyacrylamide gels (PAGE) revealed that the major components were laminin and entactin. The matrix-coated beads were used to study the attachment, spreading, and growth of African Green monkey BSC-40, human mammary MCF-7, mouse fibroblast L929, rat liver clone 9, and rat hepatoma H-4-II-E cells in defined serum-free growth medium. The different cell lines exhibited varying responses to matrix-coated vs uncoated beads with respect to rate of attachment, spreading, and growth. One of the most consistent responses observed was the enhancement of cell spreading on matrix-coated beads. The results suggested that the matrix-coated beads will provide a readily available and valuable tool for studies on cell surface-extracellular matrix interactions and the physiological consequences of those interactions. 相似文献
3.
Angiogenesis. 总被引:13,自引:0,他引:13
4.
The psychrophile Clostridium sp. strain 69 contains a thermolabile triose phosphate isomerase which is inactivated rapidly in vitro and in vivo at 32 C. 相似文献
5.
Liangmiao Wu Xinhua Zhou Yiwan Cao Shing Hung MAK Ling Zha Ning Li Zhiyang Su Yifan Han Yuqiang Wang Maggie Pui Man Hoi Yewei Sun Gaoxiao Zhang Zaijun Zhang Xifei Yang 《Aging cell》2021,20(6)
Alzheimer''s disease (AD) is a leading cause of dementia in elderly individuals and therapeutic options for AD are very limited. Over‐activation of N‐methyl‐D‐aspartate (NMDA) receptors, amyloid β (Aβ) aggregation, a decrease in cerebral blood flow (CBF), and downstream pathological events play important roles in the disease progression of AD. In the present study, MN‐08, a novel memantine nitrate, was found to inhibit Aβ accumulation, prevent neuronal and dendritic spine loss, and consequently attenuate cognitive deficits in 2‐month‐old APP/PS1 transgenic mice (for a 6‐month preventative course) and in the 8‐month‐old triple‐transgenic (3×Tg‐AD) mice (for a 4‐month therapeutic course). In vitro, MN‐08 could bind to and antagonize NMDA receptors, inhibit the calcium influx, and reverse the dysregulations of ERK and PI3K/Akt/GSK3β pathway, subsequently preventing glutamate‐induced neuronal loss. In addition, MN‐08 had favorable pharmacokinetics, blood‐brain barrier penetration, and safety profiles in rats and beagle dogs. These findings suggest that the novel memantine nitrate MN‐08 may be a useful therapeutic agent for AD. 相似文献
6.
Matthew R. Scholfield Crystal M. Vander Zanden Megan Carter P. Shing Ho 《Protein science : a publication of the Protein Society》2013,22(2):139-152
The concept of the halogen bond (or X‐bond) has become recognized as contributing significantly to the specificity in recognition of a large class of halogenated compounds. The interaction is most easily understood as primarily an electrostatically driven molecular interaction, where an electropositive crown, or σ‐hole, serves as a Lewis acid to attract a variety of electron‐rich Lewis bases, in analogous fashion to a classic hydrogen bonding (H‐bond) interaction. We present here a broad overview of X‐bonds from the perspective of a biologist who may not be familiar with this recently rediscovered class of interactions and, consequently, may be interested in how they can be applied as a highly directional and specific component of the molecular toolbox. This overview includes a discussion for where X‐bonds are found in biomolecular structures, and how their structure–energy relationships are studied experimentally and modeled computationally. In total, our understanding of these basic concepts will allow X‐bonds to be incorporated into strategies for the rational design of new halogenated inhibitors against biomolecular targets or toward molecular engineering of new biological‐based materials. 相似文献
7.
Henderson Christopher J. Stevens Tim Lee Shing Y. Gilby Ben L. Schlacher Thomas A. Connolly Rod M. Warnken Jan Maxwell Paul S. Olds Andrew D. 《Ecosystems》2019,22(6):1368-1380
Ecosystems - Animals are central to numerous ecological processes that shape the structure and function of ecosystems. It follows that species that are strongly linked to specific functions can... 相似文献
8.
Lijuan Sun Sanjay Verma Navin Michael Siew Pang Chan Jianhua Yan Suresh Anand Sadananthan Stefan G. Camps Hui Jen Goh Priya Govindharajulu John Totman David Townsend Julian Pak‐Nam Goh Lei Sun Bernhard Otto Boehm Su Chi Lim Siew Kwan Sze Christiani Jeyakumar Henry Houchun Harry Hu S. Sendhil Velan Melvin Khee‐Shing Leow 《Obesity (Silver Spring, Md.)》2019,27(9):1434-1442
9.
Suresh Anand Sadananthan Mya Thway Tint Navin Michael Izzuddin M. Aris See Ling Loy Kuan Jin Lee Lynette Pei‐Chi Shek Fabian Kok Peng Yap Kok Hian Tan Keith M. Godfrey Melvin Khee‐Shing Leow Yung Seng Lee Michael S. Kramer Peter D. Gluckman Yap Seng Chong Neerja Karnani Christiani Jeyakumar Henry Marielle Valerie Fortier S. Sendhil Velan 《Obesity (Silver Spring, Md.)》2019,27(3):470-478
10.