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961.
Hitoshi Sugiyama Shigeki Yasumasu Kenji Murata Ichiro Iuchi Kenjiro Yamagami 《Development, growth & differentiation》1998,40(1):35-45
The inner layer of the egg envelope of a teleost fish, the medaka, Oryzias latipes, consists of two major subunit groups, Zl-1,2 and Zl-3. On SDS-PAGE, the Zl-1,2 group presents three glycoprotein bands that were considered to be composed of a common polypeptide moiety derived from their precursor, choriogenin H (Chg H). Zl-3 is a single glycoprotein derived from the precursor, choriogenin L (Chg L). In the present study, a fraction of a novel subunit protein was found in the V8 protease digest of Zl-1,2 that was partially purified from oocyte envelopes. This protein fraction was not present in the purified precursor, Chg H. By RT-PCR employing the primers based on the amino acid sequence of this fraction, a cDNA for the novel subunit was amplified, and a full-length clone of the cDNA was obtained by screening a cDNA library constructed from the spawning female liver. The clone consisted of 2025 b.p. and contained an open reading frame encoding the novel protein of 634 amino acids. This protein included Pro-X-Y repeat sequences in two-fifths of the whole length from its N-terminus. Northern blot analysis revealed that the gene expression for this protein occurred in the liver but not in the ovary of spawning female fish. This protein is considered as the third major subunit of the inner layer of the egg envelope of medaka. 相似文献
962.
Hirotaro Iwase Takehiko Takatori Masataka Nagao Hitoshi Niijima Kimiharu Iwadate Yukimasa Matsuda Masahiko Kobayashi 《Free radical biology & medicine》1998,24(9):1492-1503
To observe lipid peroxidation of additive-free submitochondrial particles, we incubated submitochondrial particles in the absence of exogenous irons and t-butyl hydroperoxide. After the incubation, the phospholipids were hydrolyzed by phopholipase A2, and the fatty acid constituents were analyzed by high-performance liquid chromatography, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry. Contrary to a commonly accepted theory, lipid peroxidation in the submitochondrial particles did not need the addition of NADH. In the phospholipid constituent fatty acids of the oxidized submitochondrial particles, derivatives of hydroperoxides of linoleic acid such as keto, hydroxy, trihydroxy, and hydroxyepoxy compounds were generated. Lipid peroxidation in the submitochondrial particles was not inhibited by the addition of catalase, superoxide dismutase, hydroxyl radical scavengers, or ethylenediaminetetraacetic acid, but was inhibited by the addition of KCN, antimycin-A, NADH, ubiquinol, deferoxamine mesylate, ascorbic acid, and -tocopherol. The cardiolipin–cytochrome c lipid peroxidation system could mimic the lipid peroxidation of the submitochondrial particles, in terms of linoleic acid products and the inhibitory patterns of radical scavengers and electron transfer chain inhibitors. Thus, lipid peroxidation in the submitochondrial particles seems to be due to phospholipid–hemoprotein lipid peroxidation systems such as the cardiolipin–cytochrome c system. 相似文献
963.
Effect of DNA preparation from laver (Porphyra yezoensis) thalli on reproducibility of RAPD (random amplified polymorphic DNA) patterns 总被引:2,自引:0,他引:2
Yuzuru Mizukami Hitoshi Kito Masahiko Kunimoto Masahiro Kobayashi 《Journal of applied phycology》1998,10(1):23-29
Laver (Porphyra yezoensis) DNAs were extracted from thalli with five different procedures and used for RAPD (random amplified
polymorphic DNA) analysis as templates. Restriction enzyme-digestive DNAs were obtained with all procedures examined. However,
RAPD patterns generated with these DNAs appeared highly irreproducible and were considerably different from each other. When
DNAs purified with CsCl gradient centrifugation were used for RAPD analysis as templates, highly reproducible RAPD patterns
were obtained, suggesting that unpurified DNAs extracted from thalli with all five extraction procedures contained an excess
of RNA, polysaccharides and/or other materials which affected the RAPD reproducibility. Thus, results indicated that purification
of DNA is essential to produce reproducible RAPD patterns of Porphyra DNA.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
964.
Atsubo Kushi Koji Edamura Masato Noguchi Kiyotaka Akiyama Yoshisuke Nishi Hitoshi Sasai 《Mammalian genome》1998,9(4):269-273
A method of generating mice from embryonic stem (ES) cells with a large chromosomal deletion produced by X-ray irradiation
has been developed. Fifty-two mutant ES clones were made that carried a nested set of chromosomal deletions up to approximately
10 cM in length around the hprt locus on the X Chromosome (Chr). Germline chimeras were generated from three ES clones with deletions ranging from 200 to
700 kb. In germline male mice from two independent clones, deletions around the hprt locus yielded a runty phenotype or caused death at birth. The runty mice had approximately ⅓ the body weight and size of
wild littermates and did not survive more than 3 weeks after birth. The most plausible cause of these phenotypes is defects
in regions flanking the hprt locus. This method of creating mutant mice with a large chromosomal deletion is very useful for the identification and understanding
of gene functions.
Received: 31 October 1996 / Accepted: 16 December 1997 相似文献
965.
966.
Hitoshi Takami Nobuyuki Kishibayashi Akio Ishii Toshiaki Kumazawa 《Bioorganic & medicinal chemistry》1998,6(12):2441-2448
A novel series of indole and benzimidazole derivatives were synthesized and evaluated for their inhibitory activity of rat prostatic 5α-reductase. Among these compounds, 4-{2-[1-(4,4′-dipropylbenzhydryl)indole-5-carboxamido]phenoxy}butyric acid (15) and its benzimidazole analogue 25 showed potent inhibitory activities for rat prostatic 5α-reductase (IC50 values of 9.6 ± 1.0 and 13 ± 1.5nM, respectively), with the potency very close to that of finasteride. Compound 30, in which the moiety between the benzene ring and amide bond was replaced by quinolin-4-one ring, showed almost equipotent activity (IC50 = 19 ± 6.2nM) with the correspondent amide derivative 13. This result was consistent with the previous observation that the coplanarity of this moiety might contribute to the potent inhibitory activity. 相似文献
967.
Different Modulation of Protein Kinase C Isozymes in Dibutyryl Cyclic AMP-Differentiated PC12h Cells
Yukiko Uehara-Kunugi Shun Shimohama Hitoshi Kobayakawa Hitomi Tamura Takashi Taniguchi 《Journal of neurochemistry》1994,63(1):125-132
Abstract: PC12h cells can be differentiated into sympathetic neuron-like cells by various agents, including nerve growth factor, basic fibroblast growth factor, cyclic AMP analogues, and protein kinase C (PKC) activators. To study the involvement of PKC in the process of PC12h cell differentiation by cyclic AMP treatment, PKC isozymes (α, βI, βII, and γ) were analyzed using column chromatography and immunoblotting. Two PKC isozymes, PKC(α) and PKC(βII), were predominantly detected in PC12h cells. When stimulated by dibutyryl cyclic AMP, PKC(α) levels declined in the cytosolic fraction of the cells, whereas PKC(βII) levels increased. Increased PKC(βII) levels were also detected in the particulate fraction, whereas particulate PKC(α) levels did not change. The total PKC activity decreased in the cytosolic fraction following cyclic AMP stimulation of PC12h cells, whereas it stayed constant in the particulate fraction. Fractionation on a hydroxyapatite column showed a decreased level of PKC(α) activity and a transient increase followed by a decreased level of PKC(βII) activity. This discrepancy between increased PKC(βII) immunoreactivity and reduced PKC(βII) activity suggested the presence of nonactivatable PKC(βII) in cyclic AMP-treated PC12h extract. These findings indicate that PKC(α) and PKC(βII) are differentially regulated during the differentiation of PC12h cells. In addition, the differentiation of PC12h cells triggered by cyclic AMP seems to involve characteristic alterations of PKC isozymes. 相似文献
968.
Futoshi Arakane Kohji Fukunaga Shigeko Araki Sachiko Abe Mei Satake Kohji Miyazaki Hitoshi Okamura Eishichi Miyamoto 《Journal of neurochemistry》1994,62(1):86-93
Abstract: Cyclic AMP (cAMP)-dependent protein kinase (cAMP-kinase) partially purified from the membrane fractions of rat brains was stimulated by novel phosphonogly-cosphingolipids (glycolipids) derived from the skin and nerve fibers of Aplysia kurodai. Among various glycolipids tested, a major glycolipid from the skin, 3-O-MeGalβ 1→3GalNAcα 1→3 [6'- O -(2-aminoethylphosphonyl) Galα1→2] (2-aminoethylphosphonyl→6) Glcβ 1→4GICβ1→1ceramide (SGL-II), was most potent, giving half-maximal activation at 32.2 μ M. Activation of cAMP-kinase was maximal with 250 μ M SGL-II using kemptide as substrate. The effect of SGL-II was additive on kinase activity at submaximal concentrations of cAMP. The kinase activity activated with SGL-II was inhibited by the addition of protein kinase inhibitor peptide, a specific peptide inhibitor for cAMP-kinase. Its inhibitory pattern was similar to that for the catalytic subunit. Of the various substrates tested, the glycolipid-stimulated cAMP-kinase could phosphorylate microtubule-associated protein 2, synapsin I, and myelin basic protein but not histone H1 and casein. The regulatory subunit strongly inhibited the activity of purified catalytic subunit of cAMP-kinase. This inhibition was reversed by addition of SGL-II, as observed for cAMP. SGL-II was capable of partially dissociating cAMP-kinase, which was observed by gel filtration column chromatography. However, the binding activity of cAMP to the holoenzyme was not inhibited with SGL-II. These results demonstrate that the glycolipids can directly activate cAMP-kinase in a manner similar, but not identical, to that of cAMP. 相似文献
969.
Kusumi Kensuke; Inada Hitoshi; Kawabata Shun-ichiro; Iba Koh; Nishimura Mitsuo 《Plant & cell physiology》1994,35(3):445-449
Temperature-sensitive mutants of rice, designated virescent(v1, v2 and v3), develop chlorophyll-deficient leaves at a restrictivetemperature (20°C) but develop nearly normal green leavesat a permissive temperature (30°C). Analysis of the chlorophyllbiosynthetic pathway in the virescent mutants indicated thatthe chlorophyll deficiency at the restrictive temperature wasdue to specific blockage of the C5-pathway. Northern analysissuggested that the chlorophyll deficiency in the virescent mutantswas caused by specific inhibition of the expression of chloroplasttRNAGlu. (Received October 22, 1993; Accepted January 25, 1994) 相似文献
970.