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排序方式: 共有375条查询结果,搜索用时 62 毫秒
81.
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Anthony S. Basile Kuniaki Saito Yong Li Melvyn P. Heyes 《Journal of neurochemistry》1995,64(6):2607-2614
Abstract: Quinolinic acid is an excitatory, neurotoxic tryptophan metabolite proposed to play a role in the pathogenesis of hepatic encephalopathy. This involvement was investigated in rat and rabbit models of fulminant hepatic failure at different stages of hepatic encephalopathy. Although plasma and brain tryptophan levels were significantly increased in all stages of hepatic encephalopathy, quinolinic acid levels increased three- to sevenfold only in the plasma, CSF, and brain regions of animals in stage IV hepatic encephalopathy. Plasma-CSF and plasma-brain quinolinic acid levels in rats and rabbits with fulminant hepatic failure were strongly correlated, with CSF and brain concentrations ∼10% those of plasma levels. Moreover, there was no significant regional difference in brain quinolinic acid concentrations in either model. Extrahepatic indoleamine-2,3-dioxygenase activity was not altered in rats in stage IV hepatic encephalopathy, but hepatic l -tryptophan-2,3-dioxygenase activity was increased. These results suggest that quinolinic acid synthesized in the liver enters the plasma and then accumulates in the CNS after crossing a permeabilized blood-brain barrier in the end stages of liver failure. Furthermore, the observation of low brain concentrations of quinolinic acid only in stage IV encephalopathy suggests that the contribution of quinolinic acid to the pathogenesis of hepatic encephalopathy in these animal models is minor. 相似文献
84.
对1989年春在河北保定分离的两株乙型流感病毒进行了抗原性、HA_1基因序列和种系发生分析,与不同期的国内外代表株比较结果表明,自1988年以来乙型流感病毒变异较快,B/河北/53/89株的HA_1基因序列与B/挪威/1/85株相比,其氨基酸的同源性为94.52%,与同期的B/香港/20/89株同源性为97.12%。种系发生分析结果,从1988至1989年乙型流感病毒出现了5个支系,同期在保定分离的两株病毒,在同源替代中分别属于两个支系。日本国基本每隔两年出现一次乙型流感的流行优势型,其发生频度与甲型流感相似。国内少见乙型的流行优势型,可能和使用的分离病毒材料有关,日本用MDCK细胞比国内用鸡胚对乙型流感病毒的分离阳性率高。 相似文献
85.
Ikuei Nukaya Kuniaki Takagi Takefumi Kawabe Yasunobu Suketa 《Microbiology and immunology》1995,39(9):709-714
We examined the effect of nitric oxide (NO) on cytokine production in T helper (Th) cell subsets, using murine splenic CD4+ T cells and two types of Th clones. Interferon-gamma-treated murine peritoneal exudate cells (IFN-PEC) suppressed DNA synthesis to 60% of the control level in CD4+ T cells stimulated with the anti-CD3 monoclonal antibody. The production of IL-2 and IL-4 in the CD4+ T cells decreased to 63.2% and 9.2%, respectively, of the control value by co-culture with IFN-PEC. The addition of NG-monomethyl-L -arginine (L-NMMA) partially recovered the suppression of DNA synthesis. In the presence of indomethacin, the suppression of DNA synthesis was partially inhibited and the reduction in the cytokine production caused by IFN-PEC was partially recovered. The simultaneous addition of NG-monomethyl-L -arginine (L-NMMA) and indomethacin completely inhibited not only the suppression of DNA synthesis but also the reduction in the cytokine production caused by IFN-PEC. Moreover, DNA synthesis in the Th2 clone was suppressed to a greater extent than that in the Th1 clone by co-culture with IFN-PEC. This suppression in the Th1 clone was inhibited by the addition of L-NMMA, whereas the DNA synthesis in the Th2 clone was not recovered by L-NMMA. In addition, sodium nitroprusside (SNP) suppressed IL-4 production in the Th2 clone but had no effect on IL-2 production in the Th1 clone. In the experiment of the co-culture with IFN-PEC, the inhibitory-effect of NO on T cell activation was not clarified by the influence of prostaglandins. However, in conclusion, cytokine production in Th2 cells may be more susceptible to NO than that in Th1 cells. 相似文献
86.
Propionic acidemia is an inborn error of organic acid metabolism caused by a deficiency of propionyl Coenzyme A (CoA) carboxylase. cDNAs sequenced from a subunit deficient Japanese patient (no. 187) showed an in-frame 57-bp deletion in one allele. Genomic DNA analysis revealed a four-nucleotide deletion of bases 3 to 6 in the 3 intron adjacent to the deleted exon, which disrupted the consensus 5 splice signal and caused exon skipping. This deletion removed one-half of a tetranucleotide direct repeat at the splice junction and presumably resulted from slipped mispairing. 相似文献
87.
Denda Tetsuo Kosuge Keiko Watanabe Kuniaki Ito Motomi Suzuki Yohei Short Philip S. Yahara Tetsukazu 《Plant molecular biology》1995,28(6):1067-1073
Eighteen polymerase chain reaction (PCR) products of the partial sequence of the Adh (alcohol dehydrogenase) gene from 10 Brachyscome species were sequenced and compared. These products contained the 5 three fourths of exon 4 and whole sequences of intron 3. They varied extensively in length due to the differences in length of intron 3. A total of 10 long insertions were flanked by direct repeats of 5 to 12 bp sequences, indicating inserted elements. These inserted elements were classified into the following five categories based on nucleotide sequence characteristics and length; (1) a region homologous to that of 5S RNA genes (5S DNA), (2) A-rich structure at the 3 end-like short interspersed elements (SINEs) in animals, (3) a sequence of 280 bp with no characteristic features, (4) a sequence of 125 bp with no characteristic features, (5) termini of 11 bp inverted repeats flanked by 5 bp sequence of direct repeats characteristics of a transposon. 相似文献
88.
Junko Adachi Kuniaki Watanabe Kiichi Fukui Nobuko Ohmido Keiko Kosuge 《Journal of plant research》1997,110(3):371-377
The chromosomal locations of the 45S (18S-5.8S-26S) and 5S ribosomal DNA in theBrachyscome lineariloba complex and two related species have been determined by the use of multicolor fluorescencein situ hybridization (McFISH). TheBrachyscome lineariloba complex includes five cytodemes with 2n=4, 8, 10, 12 and 16. Each of the 5S and 45S rDNA loci occurs at two sites on chromosomes in cytodemes with 2n=4. While in cytodemes with 2n=8, 10, 12 and 16, the number of 5S rDNA sites increases from four to eight paralleled to the genomic addition of diploid
(4 chromosomes) or haploid (2 chromosomes) dosage. Of the 5S rDNA sites, only one pair is major, except for the cytodeme with
2n=10. The remaining 5S rDNA sites are minor and seem to have reduced the unit number of the 5S rDNA during the successive genomic
additions. The 45S rDNA site is detected only at two nucleolar organizing regions in all cytodemes regardless of successive
genomic addition. The loss or diminution of 45S rDNA sequences seem to have proceeded more rapidly than 5S rDNA sequences
in theB. lineariloba complex. 相似文献
89.
90.
Katsutoshi Ando Yoshinori Okada Miki Akiba Takashi Kondo Tomohiro Kawamura Meinoshin Okumura Fengshi Chen Hiroshi Date Takeshi Shiraishi Akinori Iwasaki Naoya Yamasaki Takeshi Nagayasu Masayuki Chida Yoshikazu Inoue Toyohiro Hirai Kuniaki Seyama Michiaki Mishima Respiratory Failure Research Group of the Japanese Ministry of Health Labour Welfare 《PloS one》2016,11(1)