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排序方式: 共有6621条查询结果,搜索用时 31 毫秒
931.
932.
933.
Yukio Sasaki Misato Takimoto Kyoko Oda Thomas Früh Michihiro Takai Toshikazu Okada Seiji Hori 《Journal of neurochemistry》1997,68(5):2194-2200
Abstract: Excessive release of glutamate, from glial cells as well as neurons, is thought to be a major cause of neuronal death in ischemia. To investigate glutamate release from glial cells, we measured glutamate efflux from cultures of rat astrocytes preloaded with l -[3 H]-glutamate. Glutamate efflux was induced by either 60 m M KCl or Na+ -free medium, suggesting that the efflux is due to the reversed operation of a Na+ - and K+ -coupled glutamate uptake machinery. While investigating various neuropeptides and neurotransmitters, we found that endothelin (ET) specifically induced efflux of glutamate. Northern blot analysis and binding study showed that the ET type B receptor (ETB -R) subtype was expressed two to three times more densely than the ET type A receptor (ETA -R) in astrocytes. The ETB -R antagonist IRL 2500 partially inhibited efflux of glutamate induced by 1 n M ET-1 in a concentration-dependent manner, causing a maximal inhibition of 60% at 1 µ M . However, the ETA -R antagonist BQ-123 did not cause significant inhibition even at 10 µ M . Combination of both antagonists completely inhibited the ET-1-induced efflux. These results indicate that both receptor subtypes are involved in efflux of glutamate with a major contribution from the ETB -R. Our findings suggest that ET, which is known to be released in ischemia, may exacerbate neurodegeneration by stimulating efflux of glutamate. 相似文献
934.
Fluorescence banding patterns of the rat chromosomes 总被引:1,自引:0,他引:1
935.
T. Sasaki M. Yamasaki B. Maruo Y. Yoneda K. Yamane A. Takatsuki G. Tamura 《Biochemical and biophysical research communications》1976,70(1):125-131
Several tunicamycin resistant mutants were obtained from NA64. One of them, B7 strain produced a 5-fold larger amount of α-amylase than NA64 did. Only the amount of α-amylase, among excreted proteins, was enhanced. Genetic analyses by transformation suggested that a single mutation in B7 induced both resistance to tunicamycin and hyperproductivity of extracellular α-amylase. 相似文献
936.
Hiroki Yanagida Takefumi Morita Juhyon Kim Keitaro Yoshida Kazuki Nakajima Yutaka Oomura Matthew J. Wayner Kazuo Sasaki 《Peptides》2008,29(6):912-918
Ghrelin is an endogenous ligand for the growth hormone (GH) secretagogue (GHS) receptor (GHS-R) and a potent stimulant for GH secretion even in infantile rats before puberty. Although the ventromedial nucleus of the hypothalamus (VMH) might be a site of action for ghrelin to induce GH release, the electrophysiological effect of ghrelin on VMH neurons in infantile rats remains to be elucidated. Thus, the purpose of the present study was to investigate the effect of ghrelin on VMH neurons using hypothalamic slices of infantile rats. Ghrelin excited a majority of VMH neurons in a concentration-dependent manner. VMH neurons that were excited by GH releasing peptide-6 (GHRP-6), a synthetic GHS, were also excited by ghrelin and vice versa. Repeated application of ghrelin to the same VMH neuron decreased progressively the excitatory responses depending on the number of times it was administered. The excitatory effect of ghrelin on VMH neurons in normal artificial cerebrospinal fluid (ACSF) persisted in low Ca2+-high Mg2+ ACSF. The present results indicate that (1) ghrelin excites a majority of VMH neurons dose-dependently and postsynaptically and (2) the excitatory effects of ghrelin are mimicked by GHRP-6 and desensitized by repeated applications of ghrelin. 相似文献
937.
Yasufumi Fuchi Takashi Fukuda Shigeki Sasaki 《Bioorganic & medicinal chemistry》2018,26(12):3254-3260
The 9-hydroxy-1,3-diazaphenoxazine-2-one unit was conjugated with the Eu3+-cyclen complex through a linker. This diazaphenoxazine group was expected as an antenna unit for the excitation of europium ion, and a selective recognition site for 8-oxo-dGTP base. Among the synthesized three derivatives, the highest fluorescence emission was obtained by the complex constructed of an ethylene linker and the cyclen unit with three N,N-dimethylacetamide groups. The Eu3+-cyclen complex exhibited a selective response to the 8-oxo-dGTP in aqueous media by a time-resolved fluorescence assay. 相似文献
938.
939.
Vonoprazan‐ vs proton‐pump inhibitor‐based first‐line 7‐day triple therapy for clarithromycin‐susceptible Helicobacter pylori: A multicenter,prospective, randomized trial
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940.
Hisashi Johno Kentaro Yoshimura Yuki Mori Tokuhide Kimura Manabu Niimi Masaki Yamada Tetsuo Tanigawa Jianglin Fan Sen Takeda 《Metabolomics : Official journal of the Metabolomic Society》2018,14(4):38