全文获取类型
收费全文 | 507篇 |
免费 | 25篇 |
出版年
2022年 | 4篇 |
2021年 | 18篇 |
2020年 | 9篇 |
2019年 | 14篇 |
2018年 | 18篇 |
2017年 | 10篇 |
2016年 | 18篇 |
2015年 | 25篇 |
2014年 | 22篇 |
2013年 | 34篇 |
2012年 | 24篇 |
2011年 | 30篇 |
2010年 | 22篇 |
2009年 | 15篇 |
2008年 | 30篇 |
2007年 | 29篇 |
2006年 | 18篇 |
2005年 | 25篇 |
2004年 | 20篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 13篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有532条查询结果,搜索用时 15 毫秒
1.
The role of sodium ions in amylase secretion from rat parotid cells was studied using various Na+-free media and monensin. In a sucrose medium, amylase secretion was not stimulated by isoproterenol but was significantly stimulated by dibutyryl cAMP. In choline chloride and LiCl media, both isoproterenol and dibutyryl cAMP clearly evoked amylase release. Monensin itself elicited amylase secretion slightly, but significantly inhibited the secretion stimulated by isoproterenol or dibutyryl cAMP. The inhibitory effect of monensin was detectable even in choline chloride, LiCl and KCl media. These results indicate that sodium ions are not essential for amylase secretion from rat parotid cells and that the inhibitory effect of monensin is independent of influx of sodium ions or efflux of potassium ions. 相似文献
2.
Takuma Tanada 《Physiologia plantarum》1984,61(1):35-37
The interactions of green or red light with blue light on the dark closing of Albizzia julibrissin Durazz. pinnules have been investigated. Irradiations at 430, 450 and 470 nm progressively delay dark closing with increasing photon fluence rates. Red or green light alone has no effect. However, when the blue fluence rate is low, both red and green light interact with it and increase the delaying effect of the blue light. When the blue fluence rate is high, green light interacts with it to negate some of the effectiveness of the blue light, while red light has no effect. This is similar to results obtained previously with far-red light. It is suggested that the same unidentified photoreceptor is operating in both the far-red and blue regions. The results also indicate the presence of a blue-only absorbing photoreceptor whose action is increased by phytochrome. 相似文献
3.
Shoichi Asano Toshio Matsuda Kazuhiro Takuma Hye Sun Kim Tomoaki Sato Takashige Nishikawa Akemichi Baba 《Journal of neurochemistry》1995,64(6):2437-2441
Abstract: The effects of nitric oxide (NO)-generating agents on 45 Ca2+ uptake in rat brain slices and cultured rat astrocytes were studied in the presence of monensin, which is considered to drive the Na+ -Ca2+ exchanger in the reverse mode. Sodium nitroprusside (SNP) at >10 µ M increased monensin-stimulated Ca2+ uptake in the slices, although it did not affect high K+ -stimulated Ca2+ uptake. Another NO donor, 3-morpholinosydnonimine, was effective. The effect of SNP was antagonized by hemoglobin (50 µ M ), a NO scavenger, and mimicked by 8-bromo-cyclic GMP (100 µ M ). In rat brain synaptosomes, SNP increased monensin-stimulated Ca2+ uptake, but it did not affect high K+ -stimulated Ca2+ uptake. 8-Bromocyclic GMP, but not SNP, increased Na+ -dependent Ca2+ uptake significantly in synaptic membrane vesicles in the absence of monensin. In cultured rat astrocytes, SNP and 8-bromo-cyclic GMP increased Ca2+ uptake in the presence of ouabain and monensin, which were required for the Ca2+ uptake in the cells. These findings suggest that NO stimulates the Na+ -Ca2+ exchanger in neuronal preparations and astrocytes in a cyclic GMP-dependent mechanism. 相似文献
4.
Interleukin-4 as a potent inhibitor of bone resorption 总被引:5,自引:0,他引:5
K Watanabe Y Tanaka I Morimoto K Yahata K Zeki T Fujihira U Yamashita S Eto 《Biochemical and biophysical research communications》1990,172(3):1035-1041
A possible role of interleukin-4 (IL-4) in the regulation of bone turnover was assessed by employing a 45Ca prelabeled-fetal mouse long bone culture system. IL-4 inhibited the bone resorption stimulated by parathyroid hormone (PTH), PTH related protein (PTHrP), 1 alpha, 25, dihydroxy-vitamin D3 [1 alpha, 25 (OH)2 D3], interleukin-1 alpha and - 1 beta (IL-1 alpha, IL-1 beta) and prostaglandin E2 (PGE2). Anti-IL-4 on monoclonal antibody abolished the inhibitory effect of IL-4 on the bone resorption. These results suggest that IL-4 may play an important role on the inhibitory regulation of bone resorption. 相似文献
5.
6.
7.
Noriaki Minakawa Naoshi Kojima Takuma Sasaki Akira Matsuda 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):251-263
Abstract Synthesis of 5-carbon-substituted 1-β-d-ribofuranosylimidazole-4-carboxamides are described. Treatment of 5-iodo derivative 8 with methyl acrylate in the presence of palladium catalyst gave (E)-5-(2-carbomethoxyvinyl)-1-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)imidazole-4-carboxamide (9), followed by appropriate manipulations to afford various 5-carbon-substituted imidazole derivatives 1–7. The antileukemic activities of these imidazole nucleosides are also described. 相似文献
8.
Hema Balakrishna Bhat Takuma Kishimoto Mitsuhiro Abe Asami Makino Takehiko Inaba Motohide Murate Naoshi Dohmae Atsushi Kurahashi Kozo Nishibori Fumihiro Fujimori Peter Greimel Reiko Ishitsuka Toshihide Kobayashi 《Journal of lipid research》2013,54(10):2933-2943
A mixture of sphingomyelin (SM) and cholesterol (Chol) exhibits a characteristic lipid raft domain of the cell membranes that provides a platform to which various signal molecules as well as virus and bacterial proteins are recruited. Several proteins capable of specifically binding either SM or Chol have been reported. However, proteins that selectively bind to SM/Chol mixtures are less well characterized. In our screening for proteins specifically binding to SM/Chol liposomes, we identified a novel ortholog of Pleurotus ostreatus, pleurotolysin (Ply)A, from the extract of edible mushroom Pleurotus eryngii, named PlyA2. Enhanced green fluorescent protein (EGFP)-conjugated PlyA2 bound to SM/Chol but not to phosphatidylcholine/Chol liposomes. Cell surface labeling of PlyA2-EGFP was abolished after sphingomyelinase as well as methyl-β-cyclodextrin treatment, removing SM and Chol, respectively, indicating that PlyA2-EGFP specifically binds cell surface SM/Chol rafts. Tryptophan to alanine point mutation of PlyA2 revealed the importance of C-terminal tryptophan residues for SM/Chol binding. Our results indicate that PlyA2-EGFP is a novel protein probe to label SM/Chol lipid domains both in cell and model membranes. 相似文献
9.
Takashi Kasai Takahiko Tokuda Takuma Ohmichi Ryotaro Ishii Harutsugu Tatebe Masanori Nakagawa Toshiki Mizuno 《PloS one》2016,11(1)
The COQ2 gene encodes an essential enzyme for biogenesis, coenzyme Q10 (CoQ10). Recessive mutations in this gene have recently been identified in families with multiple system atrophy (MSA). Moreover, specific heterozygous variants in the COQ2 gene have also been reported to confer susceptibility to sporadic MSA in Japanese cohorts. These findings have suggested the potential usefulness of CoQ10 as a blood-based biomarker for diagnosing MSA. This study measured serum levels of CoQ10 in 18 patients with MSA, 20 patients with Parkinson’s disease and 18 control participants. Although differences in total CoQ10 (i.e., total levels of serum CoQ10 and its reduced form) among the three groups were not significant, total CoQ10 level corrected by serum cholesterol was significantly lower in the MSA group than in the Control group. Our findings suggest that serum CoQ10 can be used as a biomarker in the diagnosis of MSA and to provide supportive evidence for the hypothesis that decreased levels of CoQ10 in brain tissue lead to an increased risk of MSA. 相似文献