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951.
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
952.
Fluorescence banding patterns of the rat chromosomes 总被引:1,自引:0,他引:1
953.
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
954.
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
955.
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
956.
Vonoprazan‐ vs proton‐pump inhibitor‐based first‐line 7‐day triple therapy for clarithromycin‐susceptible Helicobacter pylori: A multicenter,prospective, randomized trial 下载免费PDF全文
957.
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
Introduction
Atherosclerotic diseases are the leading cause of death worldwide. Biomarkers of atherosclerosis are required to monitor and prevent disease progression. While mass spectrometry is a promising technique to search for such biomarkers, its clinical application is hampered by the laborious processes for sample preparation and analysis.Methods
We developed a rapid method to detect plasma metabolites by probe electrospray ionization mass spectrometry (PESI-MS), which employs an ambient ionization technique enabling atmospheric pressure rapid mass spectrometry. To create an automatic diagnosis system of atherosclerotic disorders, we applied machine learning techniques to the obtained spectra.Results
Using our system, we successfully discriminated between rabbits with and without dyslipidemia. The causes of dyslipidemia (genetic lipoprotein receptor deficiency or dietary cholesterol overload) were also distinguishable by this method. Furthermore, after induction of atherosclerosis in rabbits with a cholesterol-rich diet, we were able to detect dynamic changes in plasma metabolites. The major metabolites detected by PESI-MS included cholesterol sulfate and a phospholipid (PE18:0/20:4), which are promising new biomarkers of atherosclerosis.Conclusion
We developed a remarkably fast and easy method to detect potential new biomarkers of atherosclerosis in plasma using PESI-MS.958.
Yusuke Sasaki Toshiyuki Takagi Keisuke Motone Toshiyuki Shibata Kouichi Kuroda 《Bioscience, biotechnology, and biochemistry》2018,82(8):1459-1462
A co-culture platform for bioethanol production from brown macroalgae was developed, consisting of two types of engineered Saccharomyces cerevisiae strains; alginate- and mannitol-assimilating yeast (AM1), and cellulase-displaying yeast (CDY). When the 5% (w/v) brown macroalgae Ecklonia kurome was used as the sole carbon source for this system, 2.1 g/L of ethanol was produced, along with simultaneous consumption of alginate, mannitol, and glucans. 相似文献
959.
Jie Zhang Tatsunori Sasaki Wei Li Kazuya Nagata Koji Higai Feng Feng Jian Wang Maosheng Cheng Kazuo Koike 《Bioorganic & medicinal chemistry letters》2018,28(7):1194-1197
Considerable attention has been paid to protein tyrosine phosphatase 1B (PTP1B) inhibitors as a potential therapy for diabetes, obesity, and cancer. Ten caffeoylquinic acid derivatives (1–10) from leaves of Artemisia princeps Pamp. (Asteraceae) were identified as natural PTP1B inhibitors. Among them, chlorogenic acid (3) showed the most potent inhibitory activity (IC50 11.1?μM). Compound 3 was demonstrated to be a noncompetitive inhibitor by a kinetic analysis. Molecular docking simulation suggested that compound 3 bound to the allosteric site of PTP1B. Furthermore, compound 3 showed remarkable selectivity against four homologous PTPs. According to these findings, compound 3 might be potentially valuable for further drug development. 相似文献
960.
Tomoyuki Ohe Ryutaro Umezawa Yumina Kitagawara Daisuke Yasuda Kyoko Takahashi Shigeo Nakamura Akiko Abe Shuichi Sekine Kousei Ito Kentaro Okunushi Hanae Morio Tomomi Furihata Naohiko Anzai Tadahiko Mashino 《Bioorganic & medicinal chemistry letters》2018,28(23-24):3708-3711
We synthesized six novel BBR derivatives that were designed to avoid metabolic activation via ipso-substitution and evaluated for their degree of toxicity and hURAT1 inhibition. It was found that all of the derivatives demonstrate lower cytotoxicity in mouse hepatocytes and lower levels of metabolic activation than BBR, while maintaining their inhibitory activity toward the uric acid transporter. We propose that these derivatives could serve as effective uricosuric agents that have much better safety profiles than BBR. 相似文献