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71.
Hidaka M Su GN Chen JK Mukaisho K Hattori T Yamamoto G 《In vitro cellular & developmental biology. Animal》2007,43(2):49-58
Bone is a complex, highly structured, mechanically active, three-dimensional (3-D) tissue composed of cellular and matrix
elements. We previously published a report on in situ collagen gelation using a rotary 3-D culture system (CG–RC system) for
the construction of large tissue specimens. The objective of the current study was to evaluate the feasibility of bone tissue
engineering using our CG–RC system. Osteoblasts from the calvaria of newborn Wistar rats were cultured in the CG–RC system
for up to 3 wk. The engineered 3-D tissues were implanted into the backs of nude mice and calvarial round bone defects in
Wistar rats. Cell metabolic activity, mineralization, and bone-related proteins were measured in vitro in the engineered 3-D
tissues. Also, the in vivo histological features of the transplanted, engineered 3-D tissues were evaluated in the animal
models. We found that metabolic activity increased in the engineered 3-D tissues during cultivation, and that sufficient mineralization
occurred during the 3 wk in the CG–RC system in vitro. One mo posttransplantation, the transplants to nude mice remained mineralized
and were well invaded by host vasculature. Of particular interest, 2 mo posttransplantation, the transplants into the calvarial
bone defects of rats were replaced by new mature bone. Thus, this study shows that large 3-D osseous tissue could be produced
in vitro and that the engineered 3-D tissue had in vivo osteoinductive potential when transplanted into ectopic locations
and into bone defects. Therefore, this system should be a useful model for bone tissue engineering. 相似文献
72.
Hidaka A Hamaji Y Sasaki T Taniguchi S Fujimori M 《Bioscience, biotechnology, and biochemistry》2007,71(12):2921-2926
Bifidobacteria are nonpathogenic, anaerobic domestic bacteria with health-promoting properties for the host. In our previous study, Bifidobacterium longum (B. longum) were found to be localized selectively and to proliferate within solid tumors after systemic application. Additionally, B. longum transformed by shuttle-plasmid including the cytosine deaminase (CD) gene expressed active CD, converted the prodrug 5-fluorocytosine (5-FC) to 5-fluorouracil (5-FU). We also demonstrated antitumor efficacy with a transformant of B. longum in rats. In this study, we found that Bifidobacterium breve (B. breve), the smallest species of human-derived bifidobacterium, expressed the exogenous transgene (CD), that CD enzymatic activity in the transformant of B. breve was much higher, and that the segregational stability of the plasmid was greater than that of B. longum. Thus, numerous transformants of B. breve were detected solely in the tumors after systemic administration. We consider the transformant of B. breve to be more beneficial in our enzyme/prodrug therapy. 相似文献
73.
Ryu Tashiro Masahiro Iwamoto Hironobu Morinaga Tomoko Emura Kumi Hidaka Masayuki Endo Hiroshi Sugiyama 《Nucleic acids research》2015,43(14):6692-6700
DNA has recently emerged as a promising material for the construction of nanosized architectures. Chemically modified DNA has been suggested to be an important component of such architectural building blocks. We have designed and synthesized a novel H-shaped DNA oligonucleotide dimer that is cross-linked with a structurally rigid linker composed of phenylene and ethynylene groups. A rotatable DNA unit was constructed through the self-assembly of this H-shaped DNA component and two complementary DNA oligonucleotides. In addition to the rotatable unit, a locked DNA unit containing two H-shaped DNA components was also constructed. As an example of an extended locked structure, a hexagonal DNA origami dimer and oligomer were constructed by using H-shaped DNA as linkers. 相似文献
74.
75.
Yamazaki Y Kido Y Hidaka K Yasui H Kiso Y Yakushiji F Hayashi Y 《Bioorganic & medicinal chemistry》2011,19(1):595-602
A new bioactive photoaffinity probe KPU-252-B1 (4) possessing a biotin tag on the oxazole ring of a potent plinabulin derivative KPU-244 (2) was synthesized via the CuI-catalyzed Huisgen’s cycloaddition reaction to understand the precise binding mode of the diketopiperazine-based anti-microtubule agent plinabulin on tubulin. Probe 4 showed significant binding affinity toward tubulin and cytotoxicity against an HT-29 cells. A photoaffinity labeling study suggested that probe 4 specifically recognizes tubulin at a binding site that binds plinabulin or colchicine, most likely near or at the colchicine binding site, which is located at the interfacial region formed by ??-and ??-tubulin association. The results also demonstrated that probe 4 may serve as a useful plinabulin chemical probe to investigate the molecular mechanism by which anti-microtubule diketopiperazine derivatives operate. 相似文献
76.
Tagad HD Hamada Y Nguyen JT Hidaka K Hamada T Sohma Y Kimura T Kiso Y 《Bioorganic & medicinal chemistry》2011,19(17):5238-5246
Previously, we reported potent pentapeptidic BACE1 inhibitors with the hydroxymethylcarbonyl isostere as a substrate transition-state mimic. To improve the in vitro potency, we further reported pentapeptidic inhibitors with carboxylic acid bioisosteres at the P(4) and P1' positions. In the current study, we screened new P1' position 1-phenylcycloalkylamine analogs to find non-acidic inhibitors that possess double-digit nanomolar range IC(50) values. An extensive structure-activity relationship study was performed with various amine derivatives at the P1' position. The most potent inhibitor of this pentapeptide series, KMI-1830, possessing 1-phenylcyclopentylamine at the P1' position had an IC(50) value of 11.6 nM against BACE1 in vitro enzymatic assay. 相似文献
77.
Recently, we have established an in-tube in situ hybridization method named mRNA quantification after fluorescence activated
cell sorting (FACS-mQ), in which a specific RNA in a particular cell type is stained with a florescent dye, allowing the stained
cells to be selected by FACS without suffering excessive RNA degradation. Using this method, the biological characteristics
of the sorted cells can be determined by analyzing their gene expression profile. In this study, we used locked nucleic acid
(LNA) oligonucleotides, which are known to enhance both the sensitivity and specificity of RNA detection, as hybridization
probes in FACS-mQ. When we used a LNA probe targeting the human 28S sequence, we were able to efficiently separate human cells
from rat cells. Using LNA probes, the hybridization step was shortened to 1 h. After the hybridization step, 84.6% RNA was
preserved; thus, we were able to successfully measure gene expression levels in each type of cell after FACS. Providing the
LNA probe efficiently hybridizes with the target sequence, FACS-mQ with an LNA probe is a powerful tool for separating particular
cells and determining their biological characteristics by analyzing their gene expression profile. 相似文献
78.
Henri‐Obadja Kumada Jeffrey‐Tri Nguyen Taeko Kakizawa Koushi Hidaka Tooru Kimura Yoshio Hayashi Yoshiaki Kiso 《Journal of peptide science》2011,17(8):569-575
HTLV‐I is a debilitating and/or lethal retrovirus that causes HTLV‐I‐associated myelopathy/tropical spastic paraparesis, adult T‐cell leukemia and several inflammatory diseases. HTLV‐I protease is an aspartic retropepsin involved in HTLV‐I replication and its inhibition could treatHTLV‐I infection. A recombinant L40I mutant HTLV‐I protease was designed and obtained from Escherichia coli, self‐processingand purification by ion‐exchange chromatography. The protease was refolded by a one‐step dialysis and recovered activity. The cleavage efficiency of the [Ile40]HTLV‐I protease was at least 300 times higher for a fluorescent substratethan that of our previously reported recombinant His‐tagged non‐mutated HTLV‐I protease. In addition, we designed and synthesized a substrate containing a highly fluorescent Mca moiety in the fragment before the scissile bond, and a chromogenic p‐nitrophenylalanine moiety after the scissile bond that greatly amplified spectrometry detection and improved the HTLV‐I protease inhibition potency assay. The HTLV‐I protease inhibition assay with the [Ile40]HTLV‐I protease and fluorogenic substrate requires distinctively less protease, substrate, inhibitor and assay time than our previous methods. This means our new assay is more cost‐effective and more time‐efficient while being reproducible and less labor‐intensive. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
79.
We have previously shown that invariant Vα19-Jα33 TCR(+) (Vα19i T) cells suppress the disease progress in some models for organ specific autoimmune diseases and type IV allergy that deteriorate along with decline to excess in Th1- or Th17- immunity. In this study, we examined the effects of over-generation of Vα19i T cells on the Th2-controlled immunoglobulin isotype production in the models for type I allergy. IgE production by invariant Vα19-Jα33 TCR transgenic (Tg) mice was suppressed compared with that by non-Tg controls following administration with goat anti-mouse IgD antiserum or OVA, while IgG2a production was not influenced by the introduction of the transgene into the recipients. IgE production by wild type mice was similarly reduced when they were subjected to adoptive transfer with invariant Vα19-Jα33 TCR Tg(+) but not Tg(-) cells prior to immunization. Furthermore, the suppression of IgE production by these recipients was enhanced when they were previously administered with a Vα19i T cell activator, one of the modified α-mannosyl ceramides. In summary, it is suggested that Vα19i T cells have potential to participate in the homeostasis of immunity and that they suppress disease progression resulting from not only Th1- but also Th2- immunity excess. 相似文献
80.