全文获取类型
收费全文 | 1871篇 |
免费 | 127篇 |
出版年
2022年 | 14篇 |
2021年 | 22篇 |
2019年 | 16篇 |
2018年 | 41篇 |
2017年 | 24篇 |
2016年 | 40篇 |
2015年 | 53篇 |
2014年 | 53篇 |
2013年 | 88篇 |
2012年 | 107篇 |
2011年 | 99篇 |
2010年 | 61篇 |
2009年 | 60篇 |
2008年 | 93篇 |
2007年 | 83篇 |
2006年 | 96篇 |
2005年 | 92篇 |
2004年 | 94篇 |
2003年 | 77篇 |
2002年 | 76篇 |
2001年 | 41篇 |
2000年 | 65篇 |
1999年 | 44篇 |
1998年 | 21篇 |
1997年 | 28篇 |
1996年 | 21篇 |
1995年 | 22篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 40篇 |
1991年 | 33篇 |
1990年 | 31篇 |
1989年 | 25篇 |
1988年 | 27篇 |
1987年 | 24篇 |
1986年 | 17篇 |
1985年 | 11篇 |
1984年 | 13篇 |
1983年 | 26篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1979年 | 10篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1976年 | 9篇 |
1975年 | 10篇 |
1973年 | 16篇 |
1970年 | 10篇 |
1969年 | 18篇 |
1968年 | 12篇 |
排序方式: 共有1998条查询结果,搜索用时 15 毫秒
91.
Shimakawa Ginga Murakami Akio Niwa Kyosuke Matsuda Yusuke Wada Ayumi Miyake Chikahiro 《Photosynthesis research》2019,139(1-3):401-411
Photosynthesis Research - While subject to illumination, photosystem I (PSI) has the potential to produce reactive oxygen species (ROS) that can cause photo-oxidative damage in oxygenic... 相似文献
92.
Kato K Kishi T Kamachi T Akisada M Oka T Midorikawa R Takio K Dohmae N Bird PI Sun J Scott F Miyake Y Yamamoto K Machida A Tanaka T Matsumoto K Shibata M Shiosaka S 《The Journal of biological chemistry》2001,276(18):14562-14571
Extracellular serine protease neuropsin (NP) is expressed in the forebrain limbic area of adult brain and is implicated in synaptic plasticity. We screened for endogenous NP inhibitors with recombinant NP (r-NP) from extracts of the hippocampus and the cerebral cortex in adult mouse brain. Two SDS-stable complexes were detected, and after their purification, peptide sequences were determined by amino acid sequencing and mass spectrometry, revealing that target molecules were serine proteinase inhibitor-3 (SPI3) and murinoglobulin I (MUG I). The addition of the recombinant SPI3 to r-NP resulted in an SDS-stable complex, and the complex formation followed bimolecular kinetics with an association rate constant of 3.4 +/- 0.22 x 10(6) M(-1) s(-1), showing that SPI3 was a slow, tight binding inhibitor of NP. In situ hybridization histochemistry showed that SPI3 mRNA was expressed in pyramidal neurons in the hippocampal CA1-CA3 subfields, as was NP mRNA. Alternatively, the addition of purified plasma MUG I to r-NP resulted in an SDS-stable complex, and MUG I inhibited degradation of fibronectin by r-NP to 24% at a r-NP/MUG I molar ratio of 1:2. Immunofluorescence histochemistry showed that MUG I localized in the hippocampal neurons. These findings indicate that SPI3 and MUG I serve to inactivate NP and control the level of NP in adult brain, respectively. 相似文献
93.
A functional assay for detection of the mitoxantrone resistance protein, MXR (ABCG2) 总被引:26,自引:0,他引:26
Robey RW Honjo Y van de Laar A Miyake K Regis JT Litman T Bates SE 《Biochimica et biophysica acta》2001,1512(2):171-182
The fluorescent compounds rhodamine 123, LysoTracker Green DMD-26, mitoxantrone, and BODIPY-prazosin were used with the antagonist fumitremorgin C (FTC) in order to develop functional assays for the half-transporter, MXR/BCRP/ABCP1. A measure of FTC-inhibitable efflux was generated for each compound in a series of MXR-overexpressing drug-selected cell lines and in ten unselected cell lines which were used to determine if the four fluorescent compounds were sensitive enough to detect the low MXR levels found in drug-sensitive cell lines. FTC-inhibitable efflux of mitoxantrone and prazosin was found in four of the ten cell lines, SF295, KM12, NCI-H460, and A549, and low but detectable levels of MXR mRNA were also observed by Northern analysis in these cells. FTC-inhibitable mitoxantrone and prazosin efflux in both selected and unselected cell lines was found to correlate well with MXR levels as determined by Northern blotting, r(2)=0.89 and r(2)=0.70 respectively. In contrast, rhodamine and LysoTracker were not able to reliably detect MXR. Cytotoxicity assays performed on two of the four unselected cell lines confirmed increased sensitivity to mitoxantrone in the presence of FTC. FTC was found to be a specific inhibitor of MXR, with half-maximal inhibition of MXR-associated ATPase activity at 1 microM FTC. Short term selections of the SF295, KM12, NCI-H460 and A549 cell lines in mitoxantrone resulted in a small but measurable increase in MXR by both Northern blot and functional assay. These studies show that flow cytometric measurement of FTC-inhibitable mitoxantrone or prazosin efflux is a sensitive and specific method for measuring the function of the MXR half-transporter in both selected and unselected cell lines. 相似文献
94.
Summary Human 5-HT3 receptors expressed in HEK 293 cells were studied using patch-clamp techniques. The permeability ratios of cations to Na+ were Li+, 1.16; K+, 1.04; Rb+, 1.11; Cs+ 1.11; NMDG+, 0.04; Ca2+, 0.49, and Mg2+, 0.37. The permeability sequence of the alkali metal cations was Li+ > Rb+ = Cs+ > K+ > Na+. Increased external concentrations of Ca2+ or Mg2+ decreased 5-HT-induced currents at all potentials tested in a voltage-independent manner. The single-channel conductance of human 5-HT3 receptors measured by fluctuation analysis of whole-cell currents was 790 ± 100fS. Differences in the basic properties of 5-HT3 receptors between species may explain interspecies differences in pharmacological properties. 相似文献
95.
Araki K Takakura H Miyajima Y Akashi Y Kawanishi K Kakita S Kondo Y 《The Journal of General and Applied Microbiology》1999,45(4):169-176
During a study on the effect of DL-serine hydroxamate on Corynebacterium glutamicum (JCM1318, a wild strain), a mutant resistant to the drug, strain TO3002, was isolated. This mutant accumulated five Ehrlich's reagent positive fluorescent substances in the culture medium. Two major and one minor fluorescent products were isolated by preparative high-performance liquid chromatography following charcoal column chromatography from the culture supernatant. One major product was identified as anthranilic acid whose molecular ion was confirmed to be 137 by a measurement of liquid chromatography-mass spectrometry (LC-MS), and NMR spectrum coincided with that of anthranilic acid. LC-MS spectra of another major and the minor product showed that they had the same molecular weight of 299. This major product was supported to be N-glucosylanthranilic acid (N-o-carboxyphenyl-1-beta-glucosylamine) by two-dimensional (1)H and (13)C NMR analyses. The minor product was speculated to be an Amadori compound derived from N-glucosylanthranilic acid. N-Glucosylanthranilic acid accumulated in the early phase, then decreased in the late phase of the culture. In contrast, the accumulation of anthranilic acid increased remarkably in the late phase of the fermentation. Based on this phenomenon, it was assumed that N-glucosylanthranilic acid once accumulated was decomposed to form anthranilic acid, at least in large part, with the progress of fermentation. The strain TO3002 showed a leaky requirement for L-tryptophan or indole (but did not for anthranilic acid) and resistance to DL-serine hydroxamate. 相似文献
96.
Shigemitsu K Tsujishita Y Miyake H Hidayat S Tanaka N Hara K Yonezawa K 《FEBS letters》1999,447(2-3):303-306
The addition of leucine induced activation of p70S6k in amino acid-depleted H4IIE cells. Whereas the activation of p70S6k by leucine was transient, the complete amino acid stimulated p70S6k more persistently. The effect of leucine on p70S6k was sensitive to rapamycin, but less sensitive to wortmannin. Using various amino acids and derivatives of leucine, we found that the chirality, the structure of the four branched hydrocarbons, and the primary amine are required for the ability of leucine to stimulate p70S6k, indicating that the structural requirement of leucine to induce p70S6k activation is very strict and precise. In addition, some leucine derivatives exhibited the ability to stimulate p70S6k and the other derivatives acted as inhibitors against the leucine-induced activation of p70S6k. 相似文献
97.
Mikawa S Shimanuki S Morozumi T Domukai M Shinkai H Uchida Y Mikawa A Miyake M Miyake Y Hayashi N Kusumoto H Uenishi H Hayashi T Awata T 《Animal genetics》2004,35(6):445-450
Several quantitative trait loci (QTL) have been detected on SSC1qter (Sus scrofa chromosome 1qter), including QTL for the number of vertebrae, as reported in our previous study. To provide the tools for analysis of QTLs on SSC1qter, we constructed a comparative map of swine and human. In addition, we identified 26 swine STSs and mapped 16 of them on SSC1qter using the INRA - University of Minnesota porcine radiation hybrid (IMpRH) panel. We screened a BAC library using these swine STSs and developed 35 new polymorphic microsatellite markers from the BAC clones, of which 26 were informative in our reference family. We also mapped nine microsatellite markers we had isolated previously. Consequently a total of 44 new polymorphic microsatellite markers were located within a 60-cM region of SSC1qter, spanning from SW1092 to the telomere. 相似文献
98.
99.
Hattori S Kawaharada C Tazaki H Fujimori T Kimura K Ohnishi M Nabeta K 《Bioscience, biotechnology, and biochemistry》2004,68(12):2656-2659
Thermally decomposed products of (+/-)-linalyl beta-D-glucoside were analyzed by GC and GC/MS. 2,6-dimethyl-2,6-octadienes produced by mild pyrolysis of linalyl beta-D-glucopyranoside under a vacuum were detected and characterized by MS and NMR spectroscopy. This suggests that 2,6-dimethyl-2,6-octadienes are produced during thermal decomposition of the glucoside via proton transfer from the anomeric position to C-6 in the aglycon moiety. A stable isotope labeling experiment directly indicated the new reaction mechanism. 相似文献
100.
Effects of soybean beta-conglycinin on hepatic lipid metabolism and fecal lipid excretion in normal adult rats 总被引:1,自引:0,他引:1
Fukui K Kojima M Tachibana N Kohno M Takamatsu K Hirotsuka M Kito M 《Bioscience, biotechnology, and biochemistry》2004,68(5):1153-1155
beta-Conglycinin decreased blood triacylglycerol (TAG) levels in male Wistar adult rats. Liver mitochondrial carnitine palmitoyltransferase activity in the beta-conglycinin-fed group significantly increased as against the casein-fed group. Hepatic fatty acid synthase activity in the beta-conglycinin group significantly decreased as against that of the casein-fed group. Fecal fatty acid excretion in the beta-conglycinin group was significantly higher than in the casein group. 相似文献