全文获取类型
收费全文 | 275篇 |
免费 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 20篇 |
2012年 | 19篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 13篇 |
2008年 | 14篇 |
2007年 | 14篇 |
2006年 | 16篇 |
2005年 | 17篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 6篇 |
1998年 | 13篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1967年 | 3篇 |
1966年 | 1篇 |
排序方式: 共有298条查询结果,搜索用时 15 毫秒
1.
The purpose of this study was to investigate the coexistence of gamma-aminobutyric acid (GABA) and leu-enkephalin in single neurons from the corpus striatum. Monolayer cell cultures, started from newborn rat corpus striatum, were grown in serum-free medium and examined using GABA autoradiography and leu-enkephalin immunocytochemistry in a double-label protocol. Examples of cells were found which were positive for one or the other neurotransmitter or for neither transmitter, but not for both. Furthermore, cells which appear similar by morphological criteria alone differed in transmitter specificity. We conclude that the two transmitters tested are not localized within single cells and that morphology alone is inadequate to identify functional cell classes in this area. 相似文献
2.
Characteristics of the total DNA preparations isolated from apical parts of dwarf pea seedlings untreated and treated with gibberellic acid (GA3) were compared. Analytical centrifugation in a self-generated CsCl density gradient revealed the occurrence of a heavy satellite DNA band (p = 1.712 g X cm-3) in addition to the main DNA band (p = 1.696 g X cm-3) in the DNA preparation extracted from GA3-treated seedlings, that could not be detected in the DNA isolated from untreated plants. The existence of this GC-rich DNA fraction was additionally confirmed by means of derivative DNA melting profiles. Comparison of the reassociation kinetics obtained for control DNA with DNA from GA3-treated plants showed changes in the percentage distribution of three main DNA sequence classes, with different repetition frequency in the haploid pea genome. It is postulated that such a variation in the percentage of different C0t families might reflect the selective DNA replication evoked by hormonal treatment of dwarf pea plants. 相似文献
3.
Anne Messer Joseph E. Mazurkiewicz Paul Maskin 《Cellular and molecular neurobiology》1981,1(1):99-114
Dissociated neonatal rat cerebellar cells were grown on medium supplemented with 10% horse serum (HS) and compared with those grown using a serum-free supplemented (SFS) medium, modified from Bottenstein and Sato (1979). containing insulin, transferrin, progesterone, putrescine, and selenium (after an initial 24 hr in 10% horse serum). Cells survived for several weeks using either medium. Cells grown in SFS had higher levels of GABA uptake than cells grown in HS. Cellular morphology and the proportion of neurons to glial cells were similar under the two conditions. Transferrin concentrations of 0.5, 10, and 100 µg/ml were tested. Neither neuronal nor glial cells were sensitive to this 200-fold variation. The SFS medium supports survival and maturation of both neurons and glial cells from rat cerebellum. However, the medium is not completely defined since (1) one day of serum is still required and (2) the heterogeneous cell population is undoubtedly conditioning the medium to some extent.This work was supported in part by grants from the Scottish Rite Schizophrenia Research Program, N.M.J., USA, and by Biomedical Research Grant S 07-RR5394, from the National Institutes of Health, PHS/DHHS. 相似文献
4.
The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs. 相似文献
5.
6.
7.
8.
AB Zarafi AM Emechebe AD Akpa O Alabi 《Archives Of Phytopathology And Plant Protection》2013,46(4):261-268
Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight. 相似文献
9.
10.