全文获取类型
收费全文 | 3765篇 |
免费 | 264篇 |
国内免费 | 1篇 |
出版年
2023年 | 21篇 |
2022年 | 44篇 |
2021年 | 79篇 |
2020年 | 59篇 |
2019年 | 62篇 |
2018年 | 109篇 |
2017年 | 83篇 |
2016年 | 130篇 |
2015年 | 184篇 |
2014年 | 212篇 |
2013年 | 302篇 |
2012年 | 331篇 |
2011年 | 306篇 |
2010年 | 208篇 |
2009年 | 185篇 |
2008年 | 229篇 |
2007年 | 235篇 |
2006年 | 223篇 |
2005年 | 207篇 |
2004年 | 195篇 |
2003年 | 180篇 |
2002年 | 156篇 |
2001年 | 29篇 |
2000年 | 22篇 |
1999年 | 20篇 |
1998年 | 34篇 |
1997年 | 24篇 |
1996年 | 16篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 12篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有4030条查询结果,搜索用时 15 毫秒
1.
Shull A. Franklin und Ladoff Sonia 《Molecular & general genetics : MGG》1918,19(1-2):110-115
2.
Legionella pneumophila in Cooling Towers: Fluctuations in Counts, Determination of Genetic Variability by Pulsed-Field Gel Electrophoresis (PFGE), and Persistence of PFGE Patterns
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sonia Ragull Marian Garcia-Nuez Maria Luisa Pedro-Botet Nieves Sopena Maria Esteve Rafael Montenegro Miquel Sabri 《Applied microbiology》2007,73(16):5382-5384
The concentrations of Legionella pneumophila in cooling towers may vary considerably over short periods of time, producing significant fluctuations throughout the year. Despite genetic variability, in small geographical areas the same indistinguishable pulsed-field gel electrophoresis patterns may be shared among different cooling towers and persist over time. 相似文献
3.
4.
Sonia Coni Silvia Maria Serrao Zuleyha Nihan Yurtsever Laura Di Magno Rosa Bordone Camilla Bertani Valerio Licursi Zaira Ianniello Paola Infante Marta Moretti Marialaura Petroni Francesca Guerrieri Alessandro Fatica Alberto Macone Enrico De Smaele Lucia Di Marcotullio Giuseppe Giannini Marella Maroder Enzo Agostinelli Gianluca Canettieri 《Cell death & disease》2020,11(12)
5.
6.
The morphological changes in the gill chloride cells of the armored catfish, Hypostomus tietensis , were investigated after 15 days' exposure to either distilled or hard water. The thickness of the water–blood barrier in the lamellae increased significantly in fish kept in distilled water due to the high proliferation of chloride cells. The apical surface of about 68% of chloride cells was sharply reduced by the development of an apical crypt with a sponge-like surface, although no change in the chloride cell fractional area was found. In contrast, H. tietensis kept in Na+ , Cl− and Ca2+ rich water displayed no significant changes in the number of chloride cells or in their apical surface morphology compared with the control fish. Chloride cell response to ion challenge in H. tietensis suggested the involvement of different strategies to maintain homeostasis in ion-poor water, which may be related to the life history of species. 相似文献
7.
The distribution of parvalbumin (PA) cell bodies and fibers in the hypothalamus of the rat was studied using a monoclonal antibody and the avidin-biotin-peroxidase method. The densest clusters of immunoreactive perikarya were observed in the nuclei mamillare medialis, arcuatus and dorsomedialis hypothalami, whereas the corpus mamillare lateralis had the lowest density. The densest network of immunoreactive fibers was observed in the corpus mamillare lateralis and nucleus arcuatus. The corpus mamillare medialis contained a moderate number of PA fibers, whereas the nucleus dorsomedialis hypothalami had the lowest density of immunoreactive fibers. In addition, a large number of immunoreactive fibers was found in the tractus opticus and the tractus mamillo-thalamicus. Essentially, the distribution of PA in the rat hypothalamus after using a monoclonal antibody seems to be broader in comparison with previous studies carried out in the same diencephalic region of the rat. The presence of PA in several nuclei of the rat hypothalamus suggests that this protein could be directly or indirectly involved in neuroendocrine, limbic and visual functions. 相似文献
8.
I De Dios J J Calvo J I San Roman M A Plaza M A Lopez 《Archives internationales de physiologie et de biochimie》1989,97(1):37-43
The effect of Dobutamine (a beta 1-adrenergic agonist) and Terbutaline (a beta 2-adrenergic agonist) on exocrine pancreatic secretion was studied in anaesthetized rabbits, simultaneously controlling pancreatic blood flow and blood pressure. The secretion of fluid and ions (bicarbonate, sodium and potassium) was unaffected by the infusion of Dobutamine (8 micrograms.kg-1.min-1) or Terbutaline (10 micrograms.kg-1.min-1). Neither were pancreatic blood flow or mean blood pressure altered. Dobutamine or Terbutaline depress the function of the acinar cells, amylase secretion being more affected by the action of Terbutaline. The results show that beta 1 and beta 2-adrenergic stimulation has no effect on the ductular cells but does decrease the secretion by the acinar cells. 相似文献
9.
SV40 immortalizes myogenic cells: DNA synthesis and mitosis in differentiating myotubes 总被引:8,自引:0,他引:8
Sonia Lujvidin Ora Fuchs Uri Nudel David Yaffe 《Differentiation; research in biological diversity》1990,43(3):192-203
Primary skeletal muscle myoblasts have a limited proliferative capacity in cell culture and cease to proliferate after several passages. We examined the effects of several oncogenes on the immortalization and differentiation of primary cultures of rat skeletal muscle myoblasts. Retroviruses containing a SV40 large T antigen (LT) gene very efficiently immortalize myogenic cells. The immortalized cell lines retain a very high differentiation capacity and form, in the appropriate culture conditions, a very dense network of muscle fibers. As in primary culture, cell fusion is associated with the synthesis of large amounts of muscle-specific proteins. However, unlike normal myoblasts (and previously established myogenic cell lines), nuclei in the multinucleated fibers of SV40-immortalized cells synthesize DNA and enter mitosis. Thus, withdrawal from DNA synthesis is not obligatory for cell fusion and biochemical differentiation. Using a retrovirus coding for a temperature-sensitive SV40 LT, myogenic cell lines were produced in which the SV40 LT could be inactivated by a shift from 33 degrees C to 39 degrees C. The inactivation of LT induced massive cell fusion and synthesis of muscle proteins. The nuclei in those fibers did not synthesize DNA, nor did they undergo mitosis. This approach enabled the reproducible establishment of myogenic cell lines from very small populations of myoblasts or single primary myogenic clones. Activated p53 also readily immortalized cells in primary muscle cultures, however the cells of eight out of the nine cell lines isolated had a fibroblastic morphology and could not be induced to form multinucleated fibers. 相似文献
10.
By use of isoelectrofocusing, three isoenzymes with pIs of 8.40, 8.55, and 8.65 were characterized in the amylase fraction of rat pancreatic juice. Enzyme secretion in rat exocrine pancreas is affected by glucocorticoid levels; adrenalectomy led to a significant decrease in protein secretion which was more pronounced in the amylase fraction, in which the isoenzymes with pI 8.55 and 8.65 disappeared. Substitution therapy with hydrocortisone (25 mg/kg/day, for 6 days) restored exocrine pancreatic secretion to almost normal levels. Administration of hydrocortisone to control rats led to structural alterations in enzymes secreted, splitting the amylase isoenzymes with pI 8.40; this was confirmed by crossed immunoelectrophoresis. It is concluded that glucocorticoid levels play an important role in the maintenance of function of exocrine pancreas and it is suggested that, although hydrocortisone fulfills the objective of restoring enzyme secretion diminished by adrenalectomy, it is possible that intensive treatment could have undesirable effects on the structure of enzymes and could involve pancreatic disfunctionality. 相似文献