全文获取类型
收费全文 | 108篇 |
免费 | 6篇 |
专业分类
114篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 11篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1988年 | 3篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1960年 | 2篇 |
1927年 | 1篇 |
排序方式: 共有114条查询结果,搜索用时 17 毫秒
71.
Optimizing Conditions for Rat Pancreatic Islets Isolation 总被引:2,自引:0,他引:2
Many procedures have been described for rat pancreatic islet isolation. Several factors contribute to the pancreatic islet
isolation outcome. One of the main problems in islet isolation procedure is the formation of a viscouse, gellike structure
during collagenase digestion which entraps the free islets and decrease islet yield after density gradient purification. This
issue has not been addressed in most techniques described for rat islet isolation. We examined effect of various factors to
eliminate formation of gellike material and improve the islets yields. Islet isolation was performed on 26 adult male Wistar
Albino rats weighing between 280 and 350 g. We have observed that several factors affect pancreatic islet isolation. Optimum
Collagenase enzyme concentration, maintaining pH range between 7.7 and 7.9 in digestion solution, incubation temperature at
38±1 °C and addition of Calcium ion decreased the formation of gellike materials and increased islet yield. Addition of Glycerol
as a gelatin solvent has also been helpful in the reduction or complete elimination of gellike material. Precise optimization
of rat islet isolation procedure is useful to improve the islet yield in islet transplantation studies. 相似文献
72.
73.
74.
75.
Testing the covarion hypothesis of molecular evolution 总被引:6,自引:8,他引:6
The covarion hypothesis of molecular evolution states that the fixation of
mutations may alter the probability that any given position will fix the
next change. Tests of this hypothesis using the divergence of real
sequences are compromised because models of rate variation among sites
(e.g., the gamma version of the one-parameter equation) predict sequence
divergence values similar to those for the covarion process. This study
therefore focuses on the extent to which the varied and unvaried codons of
two well-diverged taxa are the same, because fewer are expected by the
covarion hypothesis than by the gamma model. The data for these tests are
the protein sequences of Cu, Zn superoxide dismutase (SOD) for mammals and
plants. Simulation analyses show that the covarion hypothesis makes better
predictions about the frequencies of varied and unhit positions in common
between these two taxa than does the gamma version of the one-parameter
model. Furthermore, the analysis of SOD tertiary structure demonstrates
that mammal and plant variabilities are distributed differently on the
protein. These results support the conclusions that the variable and
invariable codons of mammal and plant SODs are different and that the
covarion model explains the evolution of this protein better than the gamma
version of the one-parameter process. Unlike other models, the covarion
hypothesis accounts for rate fluctuations among positions over time, which
is an important parameter of molecular evolution.
相似文献
76.
77.
Purification of galectin-3 from ovine placenta: developmentally regulated expression and immunological relevance 总被引:1,自引:1,他引:1
Iglesias MM; Rabinovich GA; Ambrosio AL; Castagna LF; Sotomayor CE; Wolfenstein-Todel C 《Glycobiology》1998,8(1):59-65
Galectins, beta-galactoside-binding lectins, are extensively distributed in
the animal kingdom and share some basic molecular properties. Galectin-3, a
member of this family, is generally associated with differentiation,
morphogenesis, and metastasis. In this study, galectin-3 was isolated from
ovine placental cotyledons round the middle of the gestation period by
lactose extraction followed by affinity chromatography on lactosyl-agarose,
and separated from galectin-1 by size exclusion chromatography on a
Superose 12 column. Under native conditions this lectin behaved as a
monomer with an apparent molecular weight of approximately 29,000 and an
isoelectric point of 9.0. The partial amino acid sequence of the peptides
obtained by tryptic digestion of this protein followed by HPLC separation
showed striking homology with other members of the galectin-3 subfamily.
Furthermore, ovine placental galectin-3 exhibited specific mitogenic
activity toward rat spleen mononuclear cells. Besides, this protein
strongly reacted with a rabbit antiserum raised against a chicken galectin.
Results obtained by Western blot analysis showed that its expression was
greatly decreased in term placenta with respect to the middle of the
gestation period, suggesting a regulated expression throughout development.
相似文献
78.
79.
Mirjafari H Farragher TM Verstappen SM Yates A Bunn D Marshall T Lunt M Symmons DP Bruce IN 《Arthritis research & therapy》2011,13(5):R159
Introduction
Cardiovascular disease (CVD) is the leading cause of death in patients with inflammatory polyarthritis (IP), especially in seropositive disease. In established rheumatoid arthritis (RA), insulin resistance (IR) is increased and associated with CVD. We investigated factors associated with IR in an inception cohort of patients with early IP. 相似文献80.
Larijani B Arjmand B Amoli MM Ao Z Jafarian A Mahdavi-Mazdah M Ghanaati H Baradar-Jalili R Sharghi S Norouzi-Javidan A Aghayan HR 《Cell and tissue banking》2012,13(4):569-575
It has been predicted that one of the greatest increase in prevalence of diabetes will happen in the Middle East bear in the next decades. The aim of standard therapeutic strategies for diabetes is better control of complications. In contrast, some new strategies like cell and gene therapy have aimed to cure the disease. In recent years, significant progress has occurred in beta-cell replacement therapies with a progressive improvement of short-term and long term outcomes. In year 2005, considering the impact of the disease in Iran and the promising results of the Edmonton protocol, the funding for establishing a current Good Manufacturing Practice (cGMP) islet processing facility by Endocrinology and Metabolism Research Center was approved by Tehran University of Medical Sciences. Several islet isolations were performed following establishment of cGMP facility and recruitment of all required equipments for process validation and experimental purpose. Finally the first successful clinical islet isolation and transplantation was performed in September 2010. In spite of a high cost of the procedure it is considered beneficial and may prevent long term complications and the costs associated with secondary cares. In this article we will briefly describe our experience in setting up a cGMP islet processing facility which can provide valuable information for regional countries interested to establish similar facilities. 相似文献