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111.
The binding, internalization, intracellular translocation, and degradation of epidermal growth factor (EGF) were studied in mouse Swiss/3T3 fibroblasts under two different physiological conditions at 37°C. In serum-containing medium the maximal level of cell-bound EGF was maintained for at least 8 h without appreciable degradation in contrast to serum-free conditions. These phenomena were correlated with a difference in the intracellular site to which the receptor-bound EGF was delivered as studied using Percoll density gradients. In serum-containing medium the majority of cell-bound EGF was initially taken up into a Golgi-like vesicle of density 1.046, corresponding to the marker galactosyl transferase, and then delivered to a population of vesicles with similar density as lysosomes (? =1.068–1.110). A portion of the EGF became degraded and was released from the cell into the medium while the remainder stayed with the cells, intact, for a long period of time. In serum-free medium, EGF became associated with a heterogeneous population of vesicles with a mean density of 1.050 which do not correspond to any of the marker enzymes for subcellular organelles for which we have tested (Golgi, endoplasmic reticulum, plasma membrane, lysosomes). It is then transferred to lysosome-like vesicles (? = 1.068–1.110). We therefore propose that EGF is processed through two separate endocytotic routes which are regulated by the cell depending upon its physiological state. 相似文献
112.
Alvina G. Lai Nobuyoshi Kosaka Prasad Abnave Sounak Sahu A. Aziz Aboobaker 《Developmental biology》2018,433(2):218-226
Heterogeneity of planarian stem cells has been categorised on the basis of single cell expression analyses and subsequent experiments to demonstrate lineage relationships. Some data suggest that despite heterogeneity in gene expression amongst cells in the cell cycle, in fact only one sub-population, known as sigma neoblasts, can self-renew. Without the tools to perform live in vivo lineage analysis, we instead took an alternative approach to provide independent evidence for defining the self-renewing stem cell population. We exploited the role of highly conserved condensin family genes to functionally assay neoblast self-renewal properties. Condensins are involved in forming properly condensed chromosomes to allow cell division to proceed during mitosis, and their abrogation inhibits mitosis and can lead to repeated endoreplication of the genome in cells that make repeated attempts to divide. We find that planarians possess only the condensin I complex, and that this is required for normal stem cell function. Abrogation of condensin function led to rapid stem cell depletion accompanied by the appearance of ‘giant’ cells with increased DNA content. Using previously discovered markers of heterogeneity we show that enlarged cells are always from the sigma-class of the neoblast population and we never observe evidence for endoreplication for the other neoblast subclasses. Overall, our data establish that condensins are essential for stem cell maintenance and provide independent evidence that only sigma-neoblasts are capable of multiple rounds of cell division and hence self-renewal. 相似文献
113.
Yuri Miura Noritaka Hashii Yuki Ohta Yoko Itakura Hiroki Tsumoto Junya Suzuki Daisuke Takakura Yukiko Abe Yasumichi Arai Masashi Toyoda Nana Kawasaki Nobuyoshi Hirose Tamao Endo 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(6):1462-1471
Background
Glycosylation is highly susceptible to changes of the physiological conditions, and accordingly, is a potential biomarker associated with several diseases and/or longevity. Semi-supercentenarians (SSCs; older than 105?years) are thought to be a model of human longevity. Thus, we performed glycoproteomics using plasma samples of SSCs, and identified proteins and conjugated N-glycans that are characteristic of extreme human longevity.Methods
Plasma proteins from Japanese semi-supercentenarians (SSCs, 106–109?years), aged controls (70–88?years), and young controls (20–38?years) were analysed by using lectin microarrays and liquid chromatography/mass spectrometry (LC/MS). Peak area ratios of glycopeptides to corresponding normalising peptides were subjected to orthogonal projections to latent structures discriminant analysis (OPLS-DA). Furthermore, plasma levels of clinical biomarkers were measured.Results
We found two lectins such as Phaseolus vulgaris, and Erythrina cristagalli (ECA), of which protein binding were characteristically increased in SSCs. Peak area ratios of ECA-enriched glycopeptides were successfully discriminated between SSCs and controls using OPLS-DA, and indicated that tri-antennary and sialylated N-glycans of haptoglobin at Asn207 and Asn211 sites were characterized in SSCs. Sialylated glycans of haptoglobin are a potential biomarker of several diseases, such as hepatocellular carcinoma, liver cirrhosis, and IgA-nephritis. However, the SSCs analysed here did not suffer from these diseases.Conclusions
Tri-antennary and sialylated N-glycans on haptoglobin at the Asn207 and Asn211 sites were abundant in SSCs and characteristic of extreme human longevity.General significance
We found abundant glycans in SSCs, which may be associated with human longevity. 相似文献114.
ABA disrupted cortical microtubules in guard cells, but notin epidermal cells, with concomitant closure of stomata. Otherplant growth regulators did not disrupt the microtubles in guardcells. Thus disrution of microtubules seems to be a specificeffect of ABA in guard cells but its physiological significanceremains obscure. (Received September 11, 1995; Accepted April 26, 1996) 相似文献
115.
Sperm-activating proteins from unfertilized eggs of the Pacific herring, Clupea pallasii 总被引:1,自引:0,他引:1
Shoji Oda Yoshihiko Igarashi Hideki Ohtake Kosuke Sakai Nobuyoshi Shimizu Masaaki Morisawa 《Development, growth & differentiation》1995,37(3):257-261
Ripe unfertilized eggs of the Pacific herring, Clupea pallasii , release sperm-activating proteins into seawater at the time of fertilization. Five species of herring sperm-activating proteins (HSAP) with different pl values (4.8, 4.9, 5.0, 5.1 and 5.4) were purified from the egg-conditioned medium by gel filtration and isoelectric focusing. Molecular mass of the HSAP (pl = 5.1), the major species of the five HSAP, was determined to be 8.1 kDa by mass spectrometry. Molecular weights of all of the HSAP were estimated to be 7700 by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The first 20 amino acid sequences from N-terminal ends of three HSAP (pl = 4.9, 5.0 and 5.1) were almost identical, suggesting that the HSAP have similar structures. 相似文献
116.
Nobuyoshi Nanba 《Phycological Research》1995,43(2):121-125
The mature female conceptacle of Sargassum horneri (Turner) C. Agardh has an ostiole filled with a gelatinous plug. The oogonium in the conceptacle has cell walls that can be differentiated into a dense outer and a less dense inner microfibrillar layer. Just prior to egg release, stalk material is produced inside the outer layer and the inner layer disappears. At this stage the gelatinous plug is extruded and mucilage is released through the ostiole. The released eggs are retained on the receptacle by the stalk and are surrounded by a large amount of the mucilage. Three-celled germlings form a primary wall with a polylamellated structure of microfibril layers. In multicellular germlings that have differentiated into thallus and rhizoids, the peripheral thallus cells have an outer cell wall consisting of a microfibril layer under the primary wall, while the cell wall of the rhizoid tip has an amorphous structure. The germlings are released from the stalk and become attached to the substratum by an adhesive substance secreted from rhizoidal cells. 相似文献
117.
Shiro Ishihara Akihiko Okayama Yasuhiro Nagatomo Koichi Murai Ryozo Yamashita Masayuki Okamoto Takashi Shima Takashi Sasaki Nancy Mueller Nobuyoshi Tachibana Hirohito Tsubouchi 《Microbiology and immunology》1996,40(1):39-44
The effects of anti-asialo GM-1 antibody (AAGM) treatment on the engraftment of human T-cell leukemia virus type I (HTLV-I)-infected human T cells in severe combined immunodeficiency (SCID) mice were studied. The frequency of tumor formation in an HTLV-I-transformed human T-cell line, MT-2 cells, at the site of inoculation was significantly higher in AAGM-treated than untreated mice (P<0.05): 16/18 (89%) and 16/26 (62%), respectively. The promotive effect of AAGM treatment on tumor development was marked in the early stage (less than 3 weeks), suggesting that the immediate reaction of natural killers to the inoculated cells may be important for the prevention of tumor development. The surface phenotypes and clonality of the tumor cells were the same as the MT-2 cells inoculated. Inoculation of peripheral blood mononuclear cells (PBMC) from one of the 4 adult T-cell leukemia/lymphoma (ATL) patients resulted in the development of tumors in AAGM-treated SCID mice. However, the surface phenotypes of the cells from these tumors were a mixture of B cells and T cells, suggesting that these tumors consisted of Epstein-Barr virus-transformed B cells and HTLV-I-transformed T cells. In addition, HTLV-I was detected by polymerase chain reaction in various organs of the mice inoculated with PBMC from the ATL patient and the asymptomatic carrier examined. These results suggest that elimination of natural killer function by AAGM treatment is important, although such treatment is not always necessary for the engraftment of HTLV-I-infected cells in SCID mice. 相似文献
118.
Ryo Kubota Setsuko Noda Yimin Wang Shinsei Minoshima Shuichi Asakawa Jun Kudoh Yukihiko Mashima Yoshihisa Oguchi Nobuyoshi Shimizu 《Genomics》1997,41(3):360
We have isolated a human cDNA clone encoding a novel acidic protein of MW 55,000 that we designated “myocilin” since it has homology to myosin and is localized preferentially in the ciliary rootlet and basal body of the connecting cilium of photoreceptor cells. The deduced amino acid sequence of human myocilin showed significant homologies with nonmuscle myosin ofDictyostelium discoideumin the N-terminal region and also with olfactomedin of bullfrog in the C-terminal region. Myocilin contained a leucine zipper-like motif similar to that seen in kinectin and other cytoskeletal proteins. These findings suggest that myocilin is a novel cytoskeletal protein involved in the morphogenesis of ciliated neuroepithelium such as photoreceptor cells. The myocilin gene (MYOC) was mapped to human chromosome 1q23–q24 by fluorescencein situhybridization. 相似文献
119.
Kentaro Nagamine Jun Kudoh Shinsei Minoshima Kazuhiko Kawasaki Shuichi Asakawa Fumiaki Ito Nobuyoshi Shimizu 《Genomics》1997,42(3):528
The humanPWP2gene is the human homologue of the yeast periodic tryptophan protein 2 (PWP2) gene and is a member of the gene family that contains tryptophan-aspartate (WD) repeats. Genomic sequencing revealed that the humanPWP2gene consists of 21 exons spanning approximately 24 kb and locates just between the two genes EHOC-1 and KNP-I and distal to aNotI site of LJ104 (D21S1460) on chromosome 21q22.3. Analysis of the 5′-flanking DNA sequence revealed that the upstream region of thePWP2gene is associated with a CpG island containing theNotI site of LJ104. SincePWP2is considered to be a candidate for genetic disorders mapped in the 21q22.3 region, the information including nucleotide sequence and genomic organization of thePWP2gene should be invaluable for the mutation analysis of the corresponding genetic disorders. 相似文献
120.
Isolation and preliminary characterization of the Porphyromonas gingivalis prtC gene expressing collagenase activity 总被引:10,自引:0,他引:10
A gene, prtC, has been isolated from Porphyromonas gingivalis ATCC 53977 in Escherichia coli utilizing the plasmid vector pPL-lambda. The resultant protease positive clone NHS1, harboring plasmid pS1 with a 5.9-kilobase P. gingivalis insert, expressed an enzyme capable of hydrolyzing the synthetic collagenase substrate PZ-PLGPA as well as solubilized type I collagen. Subcloning and deletion analysis located the prtC gene at one end of the P. gingivalis DNA insert on plasmid pS1. 相似文献