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81.
Suppression of viral replication by stress-inducible GADD34 protein via the mammalian serine/threonine protein kinase mTOR pathway 总被引:1,自引:0,他引:1
Minami K Tambe Y Watanabe R Isono T Haneda M Isobe K Kobayashi T Hino O Okabe H Chano T Inoue H 《Journal of virology》2007,81(20):11106-11115
GADD34 is a protein that is induced by a variety of stressors, including DNA damage, heat shock, nutrient deprivation, energy depletion, and endoplasmic reticulum stress. Here, we demonstrated that GADD34 induced by vesicular stomatitis virus (VSV) infection suppressed viral replication in wild-type (WT) mouse embryo fibroblasts (MEFs), whereas replication was enhanced in GADD34-deficient (GADD34-KO) MEFs. Enhanced viral replication in GADD34-KO MEFs was reduced by retroviral gene rescue of GADD34. The level of VSV protein expression in GADD34-KO MEFs was significantly higher than that in WT MEFs. Neither phosphorylation of eIF2alpha nor cellular protein synthesis was correlated with viral replication in GADD34-KO MEFs. On the other hand, phosphorylation of S6 and 4EBP1, proteins downstream of mTOR, was suppressed by VSV infection in WT MEFs but not in GADD34-KO MEFs. GADD34 was able to associate with TSC1/2 and dephosphorylate TSC2 at Thr1462. VSV replication was higher in TSC2-null cells than in TSC2-expressing cells, and constitutively active Akt enhanced VSV replication. On the other hand, rapamycin, an mTOR inhibitor, significantly suppressed VSV replication in GADD34-KO MEFs. These findings demonstrate that GADD34 induced by VSV infection suppresses viral replication via mTOR pathway inhibition, indicating that cross talk between stress-inducible GADD34 and the mTOR signaling pathway plays a critical role in antiviral defense. 相似文献
82.
Hayashi A Hayashi H Chiba T Sasayama S Onozaki K 《Cancer immunology, immunotherapy : CII》2007,56(4):555-562
In order to study the effect of glycosylation on its biological activities and to develop tumor necrosis factor α (TNFα) with
less deleterious effects, N-acetylneuraminic acid (NeuAc) with a C9 spacer was chemically coupled to human recombinant TNFα. NeuAc-coupled TNFα (NeuAc-TNFα)
exhibited reduced activities in vitro by about threefold compared to native TNFα. In this study, we examined a variety of
TNFα activities in vivo. NeuAc-TNFα reduced activities in the up-regulation of serum levels of IL-6 and NOx, but comparable
activity as native TNFα in the down-regulation of the serum level of glucose. However, NeuAc-TNFα was more potent than TNFα
in the up-regulation of the serum level of serum amyloid A (SAA). NeuAc-TNFα was less toxic to mice. In addition, NeuAc-TNFα
exhibited an augmented anti-tumor activity against Meth-A fibrosarcoma without hemorrhagic necrosis. These results indicate
that coupling with NeuAc enabled us to develop neoglycoTNFα with selective activities in vivo, including enhanced anti-tumor
activity but reduced toxicity. 相似文献
83.
Inamori Y Ota M Inoko H Okada E Nishizaki R Shiota T Mok J Oka A Ohno S Mizuki N 《Human genetics》2007,122(2):151-157
The collagen type Ι alpha Ι (COL1A1) gene encodes the extracellular matrix component, collagen, and resides in candidate MYP5
for high myopia on the chromosome 17q22–q23.3. This locus has recently been implicated in playing an important role in the
pathogenesis of experimental myopia. We investigated the association of disruptions of COL1A1 gene with high myopia by analyzing the frequency of ten SNPs in a Japanese population of 330 subjects with high myopia of
−9.25 D or less and 330 randomized controls without high myopia. Two SNPs (rs2075555 and rs2269336) were significantly associated
with high myopia (P < 0.05, Pc < 0.1). Two different haplotype blocks in COL1A1 were observed by the pair-wise linkage disequilibrium between the SNPs. The frequency of GGC/GGC diplotype constructed by
the three SNPs (rs2075555, rs2269336, rs1107946) was significantly high (OR = 1.6) and associated with high myopia (P = 0.028, Pc< 0.084). Together our results provide the first evidence for COL1A1 as a gene associated with high myopia. 相似文献
84.
Hayashi A Chiba T Hayashi H Sasayama S Ishiguro T Onozaki K 《Cancer immunology, immunotherapy : CII》2007,56(4):545-553
In order to study the effect of glycosylation on its biological activities, and to develop TNFα with less deleterious effects,
recombinant human TNFα was chemically coupled with N-acetylneuraminic acid (NeuAc). NeuAc with C9 spacer was coupled to TNFα by acyl azide method. Two glycosylated TNFαs, designated
L NeuAc-TNFα and H NeuAc-TNFα, were purified by anion-exchange chromatography. NeuAc coupling to TNFα was confirmed by lectin
blotting. Average number of carbohydrate molecules introduced per molecule of L NeuAc-TNFα and H NeuAc-TNFα were estimated
to be 1.0 and 1.5, respectively. We examined a variety of TNFα activities in vitro, including antiproliferative or cytotoxic
activities to tumor cells, proliferative effect on fibroblast cells, stimulatory effects on IL-6 production by melanoma cells
and NF-κB activation in hepatoma cells. L NeuAc-TNFα and H NeuAc-TNFα exhibited reduced activities about 1/3 and 1/10 as compared
to native TNFα in all the activities performed in vitro. 相似文献
85.
Polypseudorotaxanes of pegylated insulin with cyclodextrins: application to sustained release system
Higashi T Hirayama F Arima H Uekama K 《Bioorganic & medicinal chemistry letters》2007,17(7):1871-1874
The monosubstituted insulin with poly(ethylene glycol) (PEG, MW about 2200) formed polypseudorotaxanes with alpha- and gamma-cyclodextrins (CyDs), by inserting one PEG chain of the pegylated insulin in the alpha-CyD cavity and two PEG chains in the gamma-CyD cavity. The pegylated insulin/alpha- and gamma-CyD polypseudorotaxanes were less soluble in water and the release rate of the drug decreased in the order of drug alone > the gamma-CyD polypseudorotaxane > the alpha-CyD polypseudorotaxane. The subcutaneous administration of the pegylated insulin/gamma-CyD polypseudorotaxane in rats significantly sustained plasma glucose levels with an enhanced hypoglycemic effect. The results indicated that the pegylated insulin/CyD polypseudorotaxanes can work as a sustained drug release system and the polypseudorotaxane formation may be useful as a sustained drug delivery technique for pegylated proteins and peptides. 相似文献
86.
Comparative metagenomics revealed commonly enriched gene sets in human gut microbiomes. 总被引:10,自引:1,他引:9
Ken Kurokawa Takehiko Itoh Tomomi Kuwahara Kenshiro Oshima Hidehiro Toh Atsushi Toyoda Hideto Takami Hidetoshi Morita Vineet K Sharma Tulika P Srivastava Todd D Taylor Hideki Noguchi Hiroshi Mori Yoshitoshi Ogura Dusko S Ehrlich Kikuji Itoh Toshihisa Takagi Yoshiyuki Sakaki Tetsuya Hayashi Masahira Hattori 《DNA research》2007,14(4):169-181
Numerous microbes inhabit the human intestine, many of which are uncharacterized or uncultivable. They form a complex microbial community that deeply affects human physiology. To identify the genomic features common to all human gut microbiomes as well as those variable among them, we performed a large-scale comparative metagenomic analysis of fecal samples from 13 healthy individuals of various ages, including unweaned infants. We found that, while the gut microbiota from unweaned infants were simple and showed a high inter-individual variation in taxonomic and gene composition, those from adults and weaned children were more complex but showed a high functional uniformity regardless of age or sex. In searching for the genes over-represented in gut microbiomes, we identified 237 gene families commonly enriched in adult-type and 136 families in infant-type microbiomes, with a small overlap. An analysis of their predicted functions revealed various strategies employed by each type of microbiota to adapt to its intestinal environment, suggesting that these gene sets encode the core functions of adult and infant-type gut microbiota. By analysing the orphan genes, 647 new gene families were identified to be exclusively present in human intestinal microbiomes. In addition, we discovered a conjugative transposon family explosively amplified in human gut microbiomes, which strongly suggests that the intestine is a 'hot spot' for horizontal gene transfer between microbes. 相似文献
87.
Human CD93, a receptor for complement component 1, subcomponent q phagocytosis (C1qRp), has been shown to be selectively expressed by cells of a myeloid lineage and was originally reported to be involved in the C1q-mediated enhancement of phagocytosis in innate and adaptive immune responses. The modulation of CD93 expression has been investigated in various cells, particularly in granulocytes and monocytes . We previously reported that a protein kinase C activator (PKC), phorbol myristate acetate (PMA), effectively up-regulated CD93 expression on several cultured cell lines and that its regulation was mainly controlled by a PKC delta-isoenzyme. However, the expression pattern of CD93 in myeloid cells with apoptotic properties remains poorly understood. In this study, we examined the modulation of CD93 expression on a human monocyte-like cell line (U937) treated with various apoptosis-inducing chemical substances : an RNA-synthesis inhibitor, actinomycin D (ActD); a DNA topoisomerase I inhibitor, camptothecin (CPT); a protein-synthesis inhibitor, cycloheximide (CHX); a DNA topoisomerase II inhibitor, etoposide (EPS); and a DNA-synthesis inhibitor, mitomycin C (MMC). Apoptosis was monitored using two-color flow cytometry with Annexin V and 7-amino actinomycin D (7AAD). The above-mentioned substances sufficiently induced the early and late stages of apoptosis, identified as Annexin V positive (+)/7AAD negative (-) cells and Annexin V positive (+)/7AAD positive (+) cells, respectively, in U937 cells after 6 hr of treatment. The modulation of CD93 expression on U937 cells during the early stage of apoptosis, gated as Annexin V positive (+)/7AAD negative (-) cells, was then investigated using a CD93 mAb (mNI-11), originally established in our laboratories, and flow cytometry using a fluorescence-activated cell sorter (FACS). The mean fluorescence intensity (MFI) of the cells that stained positive for CD93 mAb (mNI-11) among the treated U937 cells showed a dramatic decrease in expression. In addition, the expressions of HLA-class I (HLA-A, B, C), HLA-class II (HLA-DR), CD18 (lymphocyte function-associated antigen-1 beta; LFA-1beta) and CD54 (intercellular adhesion molecule-1; ICAM-1) were also markedly decreased on the treated U937 cells identified as Annexin V positive (+)/7AAD negative (-) cells (early stage of apoptosis). Interestingly, the expression patterns of CD93 on the U937 cells treated with the above-mentioned chemical substances closely resembled those of HLA-class I (HLA-A, B, C). An immunoblotting analysis showed that the expression of a surface antigen (molecular size, about 97 kDa) targeted by the CD93 mAb (mNI-11) on the U937 cells treated with various apoptosis-inducing chemical substances had clearly decreased. On the other hand, an enzyme-linked immunoassay (EIA) showed that although PMA-treated U937 cells had strongly secreted soluble CD93 (sCD93) into the culture supernatant, the secretion of sCD93 in the culture supernatant of the U937 cells treated with the above-mentioned chemical substances was not enhanced, compared with that of untreated U937 cells. Importantly, however , the U937 cells with apoptotic properties induced by various apoptosis-inducing chemical substances also rapidly (in 30 min) and strongly secreted sCD93 into the culture supernatant in the presence of PMA. Taken together, these findings indicate that the expression of the CD93 molecule identified by CD93 mAb (mNI-11) is dramatically decreased on U937 cells with apoptotic properties, and that the decrease in CD93 expression on U937 cells treated with apoptosis-inducing chemical substances may be a good model for analyzing the regulation of CD93 expression on apoptotic myeloid cells. 相似文献
88.
Naoki Kubo Hidehiro Toh Kenjiro Shirane Takayuki Shirakawa Hisato Kobayashi Tetsuya Sato Hidetoshi Sone Yasuyuki Sato Shin-ichi Tomizawa Yoshinori Tsurusaki Hiroki Shibata Hirotomo Saitsu Yutaka Suzuki Naomichi Matsumoto Mikita Suyama Tomohiro Kono Kazuyuki Ohbo Hiroyuki Sasaki 《BMC genomics》2015,16(1)
89.
Inoue H Iihara A Takahashi H Shimada I Ishida I Maeda Y 《Protein science : a publication of the Protein Society》2011,20(12):1971-1981
VHH is the binding domain of the IgG heavy chain. Some VHHs have an extremely long CDR3 that contributes to antigen binding. We studied the antigen binding ability of CDR3 by grafting a CDR3 from an antigen-binding VHH onto a nonbinding VHH. cAb-CA05-(1RI8), the CDR3-grafted VHH, had an antigen-binding ability. To find a human scaffold protein acceptable for VHH CDR3 grafting, we focused on the conserved structure of VHH, especially the N-terminal and C-terminal amino acid residues of the CDR3 loop and the Cys residue of CDR1. Human origin protein structures with the same orientation were searched in PDB and ubiquitin was selected. Ubi-(1RI8), the CDR3-grafted ubiquitin, had antigen-binding ability, though the affinity was relatively low compared to cAb-CA05-(1RI8). The thermodynamic parameters of Ubi-(1RI8) binding to HEWL were different from cAb-CA05-(1RI8). Hydrogen-deuterium exchange experiments showed decreased stability around the CDR3 grafting region of Ubi-(1RI8), which might explain the decreased antigen-binding ability and the differences in thermodynamic properties. We concluded that the orientation of the CDR3 sequence of Ubi-(1RI8) could not be reconstructed correctly. 相似文献
90.
Although evidence for the evolution of terrestrial species on islands continues to rapidly accumulate, little is known about the evolution of marine species in geographically isolated environments such as islands as ocean currents often facilitate gene flow among populations. In this study, we focused on marine lakes of the Palau Islands, which are considered to be true analogues of terrestrial islands for marine species. To examine evolutionary processes in marine lakes, we conducted population genetic analyses on marine lake and lagoon populations of the striped silverside, Atherinomorus endrachtensis, using two mitochondrial DNA markers differing in evolutionary rate, the cytochrome b gene and the control region. The analyses revealed that the amount of genetic diversity of marine lake populations is much lower than that of lagoon populations and high levels of genetic differentiation occur among marine lake and lagoon populations. The present study has shown that marine lake populations have been completely isolated and have differentiated from lagoon populations, and each marine lake population is experiencing different evolutionary processes. These findings clearly demonstrate that marine lakes are excellent environments for the evolutionary study of marine species. 相似文献