全文获取类型
收费全文 | 256篇 |
免费 | 17篇 |
出版年
2022年 | 1篇 |
2021年 | 8篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2016年 | 8篇 |
2015年 | 10篇 |
2014年 | 9篇 |
2013年 | 19篇 |
2012年 | 6篇 |
2011年 | 17篇 |
2010年 | 16篇 |
2009年 | 10篇 |
2008年 | 15篇 |
2007年 | 16篇 |
2006年 | 17篇 |
2005年 | 7篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
1970年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有273条查询结果,搜索用时 93 毫秒
1.
G Opocher A Murgia S Rocco D D'Agostino M Boscaro A Menegus F Mantero 《Hormones et métabolisme》1986,18(11):775-778
The role of calcium in the regulation of aldosterone secretion has been recently clarified. Angiotensin II and potassium stimulate aldosterone secretion through a calcium-entry dependent mechanism, while ACTH action is both calcium and cyclic AMP dependent. To establish whether also the so-called aldosterone dopaminergic regulatory system is calcium-dependent we have studied, in vitro and in vivo, the effect of verapamil, a calcium entry blocker agent, on the aldosterone-stimulating properties of the antidopaminergic drug, metoclopramide. In the rat adrenal cells perfusion system, verapamil blocked both angiotensin II and metoclopramide-stimulated aldosterone. This effect on metoclopramide action seems to be present also in vivo in normal subjects: in fact aldosterone response was slightly but significantly reduced after pretreatment with verapamil. In conclusion the results suggest that also the dopaminergic system could regulate aldosterone secretion through calcium-mediated mechanisms. 相似文献
2.
Summary Microtubules tightly cross-linked into bundles are described in the sperm cells ofBrassica oleracea pollen tubes. The sperm cells are lobed and tailed and the microtubule bundles are often located in these parts of the cells. In the present paper we suggest that the cross-linked microtubule organization could determine an intertubular sliding, probably generating a motility system that propels the sperm cells through the tube.Abbreviations GC
generative cell
- Mfs
microfilaments
- Mts
microtubules
- SC
sperm cell
- VC
vegetative cell
- VN
vegetative nucleus 相似文献
3.
Carla Tatone Christina Grietje Van Eekelen Rosella Colonna 《Molecular reproduction and development》1994,38(2):200-208
The ability of parthenogenetically activated mouse eggs to establish a plasma membrane (PM) block to sperm penetration was studied. Zona-free eggs preloaded with Hoechst 33342 were activated by exposure to ethanol or OAG (1-oleoyl-2-acetyl-sn-glycerol) and inseminated after different periods. Eggs challenged with sperm at 30- or 60-min postactivation displayed a fertilization frequency significantly lower than that of control eggs. Conversely, when insemination was carried out at 120-min postactivation, the proportion of fertilized eggs was equivalent to that observed in the control group. Moreover, we report that when the eggs were induced to resume meiosis without any notable loss of CGs (egg exposure to OAG at 100 μM external Ca2+ or to heat shock), a normal ability to be penetrated was recorded at 30-min postactivation. Similar behaviour was exhibited by eggs that underwent a CG exocytosis close to that triggered by sperm in absence of nuclear activation (microinjection of inositol 1,4,5-trisphosphate into the egg at 1 μM cytosolic concentration). Present data support the conclusion that parthenogenetically activated mouse eggs are capable of a transitory PM block response that requires both CG exocytosis and meiosis resumption to occur. © 1994 Wiley-Liss, Inc. 相似文献
4.
Manuel Remezal Pablo Gil-Loyzaga Rosella Mollicone Rafael Oriol 《Cell and tissue research》1993,274(1):21-26
The possible structure of human blood-group antigens, as found in cochlear hair cells of 3-day-old rats, is suggested. Data were obtained from immunocytochemical studies using 77 antibodies against the major human blood group antigens of the ABO, H, I and Lewis genetic systems. Neither the anti-A-related nor the anti-Lewis-related antibodies showed any positive immunoreaction on hair cells. In contrast, anti-B, anti-AB and anti-H antibodies displayed specific positive immunoreactive patterns on the hair cells. The results suggest that, in immature hair cells, two main glycoconjugate structures of the lactoseries are present: H type 2 antigen, which is the precursor of the B type 2 antigen, and the B type 2 antigen itself. Similar H and B carbohydrate structures have been reported in rat olfactory receptors. The type 2 glycoconjugates carrying these H and B antigens of auditive and olfactory receptors are resistant to fixation and paraffin embedding, suggesting that they might be glycoproteins. These auditive and olfactory H and B antigens must be different from the B-related antigens that are expressed by pseudo-unipolar neurons of rat posterior root ganglia, that are built from type 4 core chains, and that are destroyed by routine paraffin embedding procedures. 相似文献
5.
M Murgia P Pizzo D Sandoná P Zanovello R Rizzuto F Di Virgilio 《The Journal of biological chemistry》1992,267(16):10939-10941
We have exposed mouse thymocytes and P-815 mastocytoma cells to four different conditions reported to cause apoptosis: 1) incubation in the absence of mitogenic factors; 2) incubation in the presence of dexamethasone; 3) stimulation with external ATP; 4) treatment with high concentrations of the K+ ionophore valinomycin. These treatments caused DNA fragmentation to a varying extent in the two cell types. High stringency hybridization with a cDNA probe specific to a mitochondrial DNA sequence revealed that during apoptosis induced by lack of mitogenic factors, dexamethasone, or extracellular ATP, mitochondrial DNA was not fragmented. On the contrary, valinomycin caused extensive degradation of mitochondrial DNA. These results support the notion that DNA fragmentation during apoptosis is a specific nuclear event and suggest that other agents, such as valinomycin, may act less selectively. 相似文献
6.
Paolo Perticone Caterina Tanzarella Fabrizio Palitti Ruggero Ricordy Pietro Di Chiara Giuseppe Di Pietro Franco Spirito Gianpietro Diana Rosella De Salvia Marco Rizzoni 《Chromosoma》1976,56(3):243-248
The composition in segregated haploid sets of paternal and maternal chromosomes has been studied in order to verify whether their composition is uniparental of mixed, fixed or variable. Primary cultures where prepared using kidneys from hybrids of strains of Mus musculus in which the parental chromosomes are distinguishable; the maternal set consists of 20 teleocentric chromosomes, the paternal set of 9 metacentric chromosomes, derived by Robertsonian fusion and 2 telocentrics. Applying Seabright's banding technique, an analysis of segregated haploid and diploid cells, which have originated spontaneously through polyploidisation-segregation processes was carried out. It was concluded that the haploid sets have a variable composition of paternal and maternal chromosomes. 相似文献
7.
Amol A. Verma Tejasvi Hora Hae Young Jung Michael Fralick Sarah L. Malecki Lauren Lapointe-Shaw Adina Weinerman Terence Tang Janice L. Kwan Jessica J. Liu Shail Rawal Timothy C.Y. Chan Angela M. Cheung Laura C. Rosella Marzyeh Ghassemi Margaret Herridge Muhammad Mamdani Fahad Razak 《CMAJ》2021,193(23):E859
8.
9.
Benjamin J. Ridenhour Michael A. Campitelli Jeffrey C. Kwong Laura C. Rosella Ben G. Armstrong Punam Mangtani Andrew J. Calzavara David K. Shay 《PloS one》2013,8(10)