全文获取类型
收费全文 | 187篇 |
免费 | 15篇 |
国内免费 | 1篇 |
出版年
2022年 | 2篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 11篇 |
2012年 | 17篇 |
2011年 | 6篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 14篇 |
2007年 | 12篇 |
2006年 | 5篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 8篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 8篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
排序方式: 共有203条查询结果,搜索用时 15 毫秒
1.
2.
Hiroaki Kataoka Kazuki Nabeshima Naoto Komada Masashi Koono 《Virchows Archiv. B, Cell pathology including molecular pathology》1989,57(1):157-165
Two new human cell lines, RCM-1 and CoCM-1, have been established from primary colorectal adenocarcinomas. Both cell lines
were unique in that the cultures secreted trypsin inhibitors in vitro. The activities of these inhibitors were accumulated
in serum-free media of both cell lines over a period of several days. Two inhibitors (PI-1 and PI-2) were isolated from serum-free
conditioned medium in which RCM-1 was grown by anion-exchange and gel filtration high-performance liquid chromatography. PI-1
inhibited trypsin and chymotrypsin strongly, and pancreatic elastase weakly. Its molecular weight was about 57 kilodaltons
(Kd) as determined by gel filtration chromatography. It cross-reacted with the antiserum elicited against human α1-antitrypsin in double immunodiffusion. PI-1 corresponding to α1
- antitrypsin was also demonstrated immunohistochemically in both cell lines. PI-2 inhibited trypsin strongly, and chymotrypsin,
kallikrein and plasmin weakly. It had higher molecular weight (200–300 Kd) than that of PI-1, and did not crossreact with
antisera against human α1-antitrypsin, α2-macroglobulin, α1-antichymotrypsin, α2-plasmin inhibitor, inter-α-trypsin inhibitor and urinary trypsin inhibitor. RCM-1 and CoCM-1 are the first colorectal adenocarcinoma
cell lines that secrete functionally active trypsin inhibitors, including α1-antitrypsin in vitro, and are useful for the study of tumor-cell derived proteinase inhibitors. 相似文献
3.
Measurement of the cytosolic free calcium ion concentration of individual lymphocytes by microfluorometry using quin 2 or fura-2 总被引:3,自引:0,他引:3
H Komada H Nakabayashi H Nakano M Hara T Yoshida H Takanari K Izutsu 《Cell structure and function》1989,14(2):141-150
The cytosolic free calcium ion concentration ([Ca2+]i) of individual lymphocytes was measured by microfluorometry with dual excitation wavelengths using quin 2 for fura-2. Fura-2 was a more suitable fluorescent Ca2+ indicator than quin 2 for measurements of single cells because of the standard curve calibrated for fura-2 had a good linearity, and the standard deviation (SD) of the value of the intensity ratio of fura-2-loaded cells was much smaller than that of quin 2-loaded cells. The [Ca2+]i in quiescent lymphocytes was about 1 x 10(-7) M, and an increase in the [Ca2+]i was observed within a few minutes of ionomycin, protein A, phorbol myristate acetate (PMA) or concanavalin A (Con A) stimulation. Ionomycin-induced proliferation occurred when the initial [Ca2+]i was approximately 3 x 10(-7) M or greater. The increase in the [Ca2+]i induced by Con A occurred transiently, and another rise in the [Ca2+]i was observed in the stage prior to the S-phase. These results indicate that Ca2+ is necessary for stimulated lymphocytes to enter the cell cycle and S-phase. 相似文献
4.
Human hepatocyte growth factor (hHGF) consists of characteristic structural domains. In this study, we prepared mutant proteins lacking each of these domains and examined their biological activities for stimulation of hepatocyte DNA synthesis, inhibition of Meth A cell growth, and induction of MDCK cell dissociation. We also examined their interactions with the c-met/HGF receptor by competition analysis and by analysis of levels of tyrosine phosphorylation. The mutant proteins lacking the N-terminal, the first kringle, or the second kringle domain were not biologically effective and could not compete with hHGF bound to the c-met/HGF receptor. The results indicate that these domains are necessary for the biological activities of hHGF mediated by binding to the c-met/HGF receptor. The mutant proteins lacking the third or fourth kringle domain moderately retained biological activities and the receptor binding. The relative levels of the tyrosine phosphorylation of the c-met/HGF receptor by these mutant proteins correlated well with the relative potencies of the biological activities when compared with that of the wild-type hHGF. The mutant protein lacking the light chain was not effective in the biological activities and tyrosine phosphorylation of the c-met/HGF receptor, but competed with hHGF bound to the c-met/HGF receptor. These results suggest that the heavy chain plays an important role in the interaction of hHGF with the c-met/HGF receptor and that the light chain is further required for the tyrosine phosphorylation of the c-met/HGF receptor. 相似文献
5.
Arnold M. Katz Charles F. Louis Doris I. Repke Gary Fudyma Priscilla A. Nash-Adler Robert Kupsaw Munekazu Shigekawa 《生物化学与生物物理学报:生物膜》1980,596(1):94-107
Unfractionated and low buoyant density sarcoplasmic reticulum vesicles released calcium spontaneously after ATP- or acetyl phosphate-supported calcium uptake when internal Ca2+ was stabilized by the use of 50 mM phosphate as calcium-precipitating anion. This spontaneous calcium release could not be attributed to falling Ca2+ concentration outside the vesicles (Ca02+), substrate depletion, ADP accumulation, nonspecific membrane deterioration or the attainment of a high vesicular calcium content. Instead, spontaneous calcium release was directly proportional to Ca02+ at the time that calcium content was maximal. A causal relationship between high Ca02+ and spontaneous calcium release was suggested by the finding that elevation of Ca02+ from less than 1 μM to 3–5 μM increased the rate and extent of calcium release.The spontaneous calcium release was due both to acceleration of calcium efflux and slowing of calcium influx that was not accompanied by a significant change in the rate of ATP hydrolysis. Neither reversal of the transmembrane KCl gradient nor incubation with cation and proton ionophores abolished the spontaneous calcium release. The persistence of calcium release under conditions where the membrane was permeable to both anions and cations makes it unlikely that this phenomenon is due to a changing transmembrane potential. 相似文献
6.
Masayoshi Oyama Ken-ichi Nakashima Tetsuro Kamiya Manami Haba Tetsuro Ito Hiroko Murata Toshiyuki Tanaka Tetsuo Adachi Munekazu Iinuma Takeshi Kinoshita 《Phytochemistry letters》2013,6(2):215-218
Two novel flavonoids, named meliflavones A (1) and B (2), were isolated from the leaves of Melicope triphylla (Lam.) Merr., along with thirteen known compounds (3–15). Four of the polymethoxyflavonoids bearing a prenyloxy (3-methylbut-2-enyloxy) function (1, 3–5) induced the expression of extracellular-superoxide dismutase (EC-SOD) in a human leukemic U937 cell-based assay. 相似文献
7.
Tetsuro Ito Kouko Nishiya Masayoshi Oyama Toshiyuki Tanaka Jin Murata Dedy Darnaedi Munekazu Iinuma 《Phytochemistry letters》2013,6(4):667-670
Two O-glucosides of resveratrol dimers, ampelopsin F-11b-O-β-glucopyranosides with enantiomeric aglycones [cordifoloside A (1) and cordifoloside B (2)] and an enantiomer of the aglycone [(?)-ampelopsin F] were isolated from the leaves of Shorea cordifolia (Dipterocarpaceae). These structures were identified on the basis of spectroscopic evidence and their absolute configurations were elucidated using circular dichroism data. This is the first report on oligostilbenoids that demonstrates the co-occurrence of diastereomeric O-glucosides with enantiomeric aglycones in this family. 相似文献
8.
The reaction catalyzed by crystalline yeast phosphoglyceric acid mutase is inhibited by the substrate (d-2-phosphoglyceric acid). In order to elucidate the mechanism of this substrate inhibition, detailed investigations have been performed. It is proved that the substrate inhibition in this enzyme reaction is caused by the facts that the coenzyme-binding site on the enzyme is covered by the substrate and the combination of the coenzyme with the enzyme is interfered by the substrate. Consequently, it is concluded that the substrate is a competitive inhibitor of the coenzyme. 相似文献
9.
10.
Uemoto Y Suzuki S Terada N Ohno N Ohno S Yamanaka S Komada M 《The Journal of biological chemistry》2007,282(9):6548-6555
At axon initial segments and nodes of Ranvier in neurons, the spectrin membrane skeleton plays roles in physically stabilizing the plasma membrane integrity and in clustering voltage-gated sodium channels for proper conduction of the action potential. betaIV-Spectrin, an essential component of the membrane skeleton at these sites, has an N-terminal-truncated isoform, Sigma6, which is expressed at much higher levels than the full-length isoform Sigma1. To investigate the role of betaIV-spectrin Sigma6, we generated Sigma1-deficient mice with a normal level of Sigma6 expression (Sigma1(-/-) mice), and compared their phenotypes with those of previously generated mice lacking both Sigma1 and Sigma6(Sigma1Sigma6(-/-) mice). The gross neurological defects observed in Sigma1Sigma6(-/-) mice, such as hindleg contraction, were apparently ameliorated in Sigma1(-/-) mice. At cellular levels, Sigma1Sigma6(-/-) and Sigma1(-/-) neurons similarly exhibited waving and swelling of the plasma membrane at axon initial segments and nodes of Ranvier. By contrast, the levels of ankyrin G and voltage-gated sodium channels at these sites, which are significantly reduced in Sigma1Sigma6(-/-) mice, were substantially recovered in Sigma1(-/-) mice. We conclude that the truncated betaIV-spectrin isoform Sigma6 plays a specific role in clustering voltage-gated sodium channels, whereas it is dispensable for membrane stabilization at axon initial segments and nodes of Ranvier. 相似文献