全文获取类型
收费全文 | 683篇 |
免费 | 42篇 |
出版年
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2018年 | 11篇 |
2017年 | 3篇 |
2016年 | 12篇 |
2015年 | 11篇 |
2014年 | 10篇 |
2013年 | 42篇 |
2012年 | 23篇 |
2011年 | 27篇 |
2010年 | 16篇 |
2009年 | 18篇 |
2008年 | 31篇 |
2007年 | 25篇 |
2006年 | 22篇 |
2005年 | 20篇 |
2004年 | 47篇 |
2003年 | 41篇 |
2002年 | 17篇 |
2001年 | 20篇 |
2000年 | 20篇 |
1999年 | 26篇 |
1998年 | 10篇 |
1997年 | 16篇 |
1996年 | 10篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 23篇 |
1991年 | 24篇 |
1990年 | 12篇 |
1989年 | 21篇 |
1988年 | 20篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 6篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 14篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1969年 | 4篇 |
1967年 | 5篇 |
1965年 | 5篇 |
排序方式: 共有725条查询结果,搜索用时 302 毫秒
681.
A simple method was developed to isolate viable human salivary polymorphonuclear leukocytes (SPMN) from the oral cavity, and stimulation-coupled responses of these cells were examined. From morphological characteristics and the presence of neutrophil-specific annexin protein (39-kDa protein), we found that these cells seemed to be very similar to human peripheral polymorphonuclear leukocytes (PPMN), although they were in rather young stages. Stimulation-coupled responses of these cells were observed in terms of superoxide (O2.-) genration, luminol chemiluminescence response (LCL), membrane depolarization, and changes in intracellular calcium ion concentration ([Ca2+]i). The rates of superoxide generation by various stimuli, such as formylmethionylleucylphenylalanine (FMLP), phorbol 12-myristate 13-acetate (PMA) and opsonized zymosan (OZ) were different. Superoxide generation and strong chemiluminescence response were observed without addition of any stimuli. This endogenous LCL was inhibited by azide and superoxide dismutase (SOD), but not by uric acid (UA). The intensity of the endogenous LCL decreased with time after isolation from the oral cavity. This decrease was accompanied by the appearance of a FMLP-coupled response. Furthermore, the endogenous activity which produced active oxygen species was maintained in the medium at 4 degrees C for a long period after isolation. From these results, it is suggested that SPMN have the ability to show characteristic responses to various stimuli, and that SPMN play important roles in the defense mechanisms in the oral cavity. 相似文献
682.
Masanobu Miyahara Eiji Okimasu Hiroaki Mikasa Shigeo Terada Hiroyuki Kodama Kozo Utsumi 《Archives of biochemistry and biophysics》1984,233(1):139-150
The mitochondrial dysfunction induced by anoxia in vitro was improved with chlorpromazine, cepharanthine, bromophenacyl bromide, and mepacrine without affecting phospholipid or adenine nucleotide metabolisms. The drugs inhibited lipid peroxidation by Fe2+, mitochondrial disruption by Ca2+, and membrane perturbation by lysolecithin, and retained the activity to control H+ permeability across mitochondrial membranes. The drugs appeared to preserve the functions by acting to suppress the development of membrane deterioration which may have resided in the deenergization of mitochondria in the absence of oxygen. 相似文献
683.
The putative ionophoretic action of phosphatidic acid or arachidonic acid metabolites for Ca2+ has offered an attractive explanation for stimulation-coupled mobilization of cytoplasmic Ca2+. We have examined the effects of Ca2+ ionophore and long-chain unsaturated fatty acids on the translocation of Ca2+ across the liposomal membrane by using Quin II-entrapped liposomes, a sensitive assay system for ionophoresis of Ca2+. A23187 increased Quin II fluorescence intensity corresponding to the translocation of Ca2+ into liposomes. Similar translocation was observed with unsaturated long-chain fatty acids but not with saturated fatty acids. Thus, when phospholipases of cell membrane are activated by certain stimuli, unsaturated long-chain fatty acids are liberated and might mediate the mobilization of cytoplasmic Ca2+. 相似文献
684.
685.
686.
H Utsumi M M Elkind 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1985,47(5):569-580
The effect on the survival of X-irradiated Chinese hamster cells (line V79) of two different post-treatments is examined in plateau- and in log-phases of growth. Qualitatively similar results are obtained with cells in both growth phases; that is, similar reductions in survival are effected by post-treatments with hypertonic phosphate buffered saline, and similar increases in survival are effected by post-treatments with conditioned medium. In addition, in both kinds of cells the kinetics of the repair processes are similar even though the kinetics of the two processes differ from each other considerably. While the results indicate that there can be essential differences in the type and/or the pathways of repair of potentially lethal damage, they also illustrate a broader meaning of this term than has been customary. Considered relative to the amount of DNA damage that can be expected to be potentially lethal, it is concluded that the two types of damage that are the subjects of this study represent only small sectors of the total amount of potentially lethal damage. 相似文献
687.
Takashima Natsuki Ishino Sonoko Oki Keisuke Takafuji Mika Yamagami Takeshi Matsuo Ryotaro Mayanagi Kouta Ishino Yoshizumi 《Extremophiles : life under extreme conditions》2019,23(1):161-172
Extremophiles - DNA polymerase D (PolD), originally discovered in Pyrococcus furiosus, has no sequence homology with any other DNA polymerase family. Genes encoding PolD are found in most of... 相似文献
688.
M Tsunoi Y Hakeda N Kurihara N Maeda N Utsumi M Kumegawa 《Experimental cell research》1984,153(1):240-244
The effect of transferrin was tested on osteoblastic cells (clone MC3T3-E1) cultured in serum-free medium containing 1% bovine serum albumin (BSA). Transferrin (Tf) stimulated increases of protein content and protein synthesis, but not of DNA content and cell number, in the cells. This protein also increased alkaline phosphatase activity and collagen synthesis in combination with 1% BSA. Actinomycin D and cycloheximide inhibited alkaline phosphatase activity induced by Tf, suggesting that Tf may enhance de novo synthesis of the enzyme. These results indicate that Tf may be involved in differentiation of osteoblastic cells, but not in their proliferation, in vitro. 相似文献
689.
690.
E Sato K Edashige T Utsumi B Inoue M Miyahara K Utsumi 《Physiological chemistry and physics and medical NMR》1986,18(2):79-87
Various stimuli act on polymorphonuclear leukocytes (PMN), activating membrane-bound phospholipase A2 and C, and diglyceride lipase and then liberating unsaturated fatty acids (USFAs). These liberated USFAs are immediately metabolized through various metabolic pathways such as cyclooxygenase, lipoxygenase, phosphatidylinositol metabolism etc. It is possible that the metabolic intermediates of these pathways reveal various physiological actions. This work was undertaken to clarify whether stimuli on PMN depend on these USFAs themselves or on their oxidation products. The following results were obtained: 1. USFAs such as arachidonate and linoleate stimulate PMN, accelerating superoxide (O2) generation, depolarization of membrane potential and increase in [Ca2+]i. 2. Oxidation products of USFAs have no stimulative effect on PMN. The decrease in the stimulative effect of these USFAs following their oxidation is proportional to the quantitative decrease in non-oxidized linoleate. 3. USFAs accelerate membrane permeability of Ca2+, and their oxidation products enhance non-specific membrane permeability in proportion to the formation of monohydroxy compound. These results suggest that stimulative effects of USFAs on PMN do not depend on their oxidation products but on unoxidized fatty acids. Furthermore, among the oxidation products of the USFAs, monohydroxy compound acts as a strong perturber of membrane and accelerates membrane permeability. 相似文献