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131.
Cysteine sulfinic acid decarboxylase (CSAD), the rate-limiting enzyme in taurine biosynthesis, appears to be present in the brain in multiple isoforms. Two distinct forms of CSAD, referred to as CSAD I and CSAD II, were obtained on Sephadex G-100 column. CSAD I and CSAD II differ in (1) the elution profile on Sephadex G-100 column; (2) the sensitivity towards Mn2+, methione, and other sulfur-containing amino acids and (3) their immunologic properties. CSAD II has been purified to about 2,500-fold by a combination of column chromatographies and polyacrylamide gel electrophoresis (PAGE). The purity of the enzyme preparation was established as judged from the following observations: (1) a single protein band was observed under various electrophoretic conditions, e.g., 5–20% nondenaturing PAGE, 7% nondenaturing PAGE and 10% SDS-PAGE and (2) in nondenaturing PAGE, the protein band comigrated with CSAD activity. CSAD II has a molecular weight of 90 kDa and is a homodimer consisting of two 43 ± 2 kDa subunits. CSAD appears to require Mn2+ for its maximum activity. Other divalent cations fail to replace Mn2+ in activation of CSAD activity. However, the precise role of Mn2+ in the action of CSAD remains to be determined. 相似文献
132.
Induction of a Nerve Growth Factor-Sensitive Kinase that Phosphorylates the DNA-Binding Domain of the Orphan Nuclear Receptor NGFI-B 总被引:2,自引:0,他引:2
Yoko Hirata Michael Whalin David D. Ginty Jun Xing Michael E. Greenberg †Jeffrey Milbrandt Gordon Guroff 《Journal of neurochemistry》1995,65(4):1780-1788
Abstract: Nerve growth factor (NGF) induces the synthesis and the phosphorylation of the orphan nuclear receptor NGFI-B in PC12 cells. Previous work has shown that phosphorylation, by protein kinase A, of a specific serine in the DNA-binding domain inhibits its binding to the NGFI-B response element. Also, cytoplasmic extracts from PC12 cells phosphorylate this serine, and phosphorylation is greater in extracts from cells treated with NGF. The present work describes the induction, identification, and partial purification of a kinase (termed NGFI-B kinase I) from PC12 cell extracts that catalyzes this phosphorylation. Phosphorylation of the DNA-binding domain with this purified preparation inhibits its binding to the NGFI-B response element. The kinase is rapidly activated by treatment of the cells with NGF, and the activation lasts for at least several hours. It also is activated by fibroblast growth factor and epidermal growth factor (EGF), but the activation by EGF is quite transient. The kinase requires Mg2+ but will use Mn2+ . The molecular mass of the kinase is 95–100 kDa, and it is different from protein kinase A, Fos kinase, or pp90 rsk . Comparison with a partially purified preparation of cyclic AMP response element-binding protein kinase, however, indicates that the two are either very similar or identical. 相似文献
133.
Inheritance of gusA and neo genes in transgenic rice 总被引:21,自引:0,他引:21
Jianying Peng Fujiang Wen Richard L. Lister Thomas K. Hodges 《Plant molecular biology》1995,27(1):91-104
Inheritance of foreign genes neo and gusA in rice (Oryza sativa L. cv. IR54 and Radon) has been investigated in three different primary (T0) transformants and their progeny plants. T0 plants were obtained by co-transforming protoplasts from two different rice suspension cultures with the neomycin phosphotransferase II gene [neo or aph (3) II] and the -glucuronidase gene (uidA or gusA) residing on separate chimeric plasmid constructs. The suspension cultures were derived from callus of immature embryos of indica variety IR54 and japonica variety Radon. One transgenic line of Radon (AR2) contained neo driven by the CaMV 35S promoter and gusA driven by the rice actin promoter. A second Radon line (R3) contained neo driven by the CaMV 35S promoter and gusA driven by a promoter of the rice tungro bacilliform virus. The third transgenic line, IR54-1, contained neo driven by the CaMV 35S promoter and gusA driven by the CaMV 35S.Inheritance of the transgenes in progeny of the transgenic rice was investigated by Southern blot analysis and enzyme assays. Southern blot analysis of genomic DNA showed that, regardless of copy numbers of the transgenes in the plant genome and the fact that the two transgenes resided on two different plasmids before transformation, the introduced gusA and neo genes were stably transmitted from one generation to another and co-inherited together in transgenic rice progeny plants derived from self-pollination. Analysis of GUS and NPT II activities in T1 to T2 plants provided evidence that inheritance of the gusA and neo genes was in a Mendelian fashion in one plant line (AR2), and in an irregular fashion in the two other plant lines (R3 and IR54-1). Homozygous progeny plants expressing the gusA and neo genes were obtained in the T2 generation of AR2, but the homozygous state was not found in the other two lines of transgenic rice. 相似文献
134.
135.
136.
云南普通马矮型马蛋白多态性及其品种分化关系 总被引:3,自引:1,他引:2
本文运用蛋白电泳技术对来自云南省文山州马关县和麻栗坡县的21匹普通马和14匹矮型马进行了分析。共分析遗传座位44个,其中有10个座位检测到多态性。根据分子钟假说和相应的公式,推算两者的分歧时间约为18.5万年。 相似文献
137.
138.
银额果蝇自然群体分化过程中的细胞遗传学 总被引:3,自引:0,他引:3
对我国大陆银额果蝇的分布及其细胞遗传学进行了广泛的调查,发现了一种值得注意的新核型。该核型结构兼有早已认可的长、短两大类基本核型的特征,即核型中的两条同源4号染色体为1长1短型。含新核型的群体分布于我国大陆东南沿海一带的上海、福州、厦门和深圳。而且,这些自然群体内还出现“1长1短型”、“长型”和“短型”重叠并存的多态现象。跟踪研究表明,新核型具有不稳定的遗传性,能世代传递,它的频率随世代增长而降低,并不是突然消失。但是,在上海、福州群体内出现的“长型”至第十五代之后却全部消失。这种新核型大概是银额果蝇自然演化过程中的中间过渡核型,是该果蝇种群分化中的细胞遗传学变异的过渡表征 相似文献
139.
冬虫夏草(Cordyceps sinensis)的随机扩增多态DNA及其遗传分化 总被引:16,自引:0,他引:16
本文对来自青藏高原3个区域5个具有代表性地方的13个冬虫夏草(Cordyceps sinensis[Berk.] Sacc.)样本进行随机扩增多态DNA(RAPD)分析。19个随机引物获得的RAPD谱带清晰并呈现多态,单个引物获得的RAPD片段数在3~10个之间。该19个引物在每个样本中扩增的RAPD片段总数平均约为65个。基于遗传距离分析,受试的13个冬虫夏草样本中,来自同一地方的样本间遗传差异甚微,同一区域不同地方的样本间遗传差异较大,不同区域的样本间遗传差异最大。这说明冬虫夏草地理群体间存在着遗传分化。应用UPGMA和NJ方法构建的分子系统树显示,来自5个地方的冬虫夏草实际上可以归并为显著不同的3个组,对应于样本来源的3个区域,提示RAPD标记在冬虫夏草群体中有显著的地区特异性。我们的结果还表明,冬虫夏草地理群体间的遗传差异度与地理距离呈正相关。因此,RAPD作为有效的遗传标记,可用于研究冬虫夏草的遗传多样性、起源以及系统演化等。 相似文献
140.
Leying Wen Hiroshi Ushijima Junko Kakizawa Zhao-Yin Fang Osamu Nishio Shigeru Morikawa Takashi Motohiro 《Microbiology and immunology》1995,39(11):911-915
Sequence analysis of the gene encoding the major neutralization glycoprotein (VP7) was performed on sixteen human isolates of serotype 2 of rotavirus in Japan, China, and Pakistan and their genetic variations were examined. Comparative studies of their nucleotide and deduced amino acid sequences between the sixteen isolates and the HU5 strain revealed an overall homology of more than 94%. A higher degree of homology in nucleotides was observed among the sixteen isolates than between HU5 and the isolates. A total of thirteen amino acid residues frequently converted to another amino acid. Out of the thirteen, five amino acid residues belonging to the major neutralizing epitope regions (C, E, and F in this communication) converted frequently. From the amino acid sequences three subtypes, subtype 1, subtype 2, and intermediate, were suggested to be classified as previously reported for serotype 1 (Xin et al, Virology, 1993, 197: 813-816). 相似文献