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991.
Cancer preventive agents. Part 8: Chemopreventive effects of stevioside and related compounds 总被引:1,自引:0,他引:1
Midori Takasaki Takao Konoshima Mutsuo Kozuka Harukuni Tokuda Junko Takayasu Hoyoku Nishino Masazumi Miyakoshi Kenji Mizutani Kuo-Hsiung Lee 《Bioorganic & medicinal chemistry》2009,17(2):600-605
In a search for potential cancer chemopreventive agents from natural resources, stevioside (1), a sweetener, and six related compounds, including two aglycones steviol (6) and isosteviol (7), were screened in an in vitro assay for inhibitory effects on Epstein–Barr virus early antigen activation. Compounds 1, 6 and 7 showed significant activity in this assay and also exhibited strong inhibitory effects in a two-stage carcinogenesis test using mouse skin induced by 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). The inhibitory effects of these three compounds were greater than that of glycyrrhizin. Furthermore, these three compounds significantly inhibited mouse skin carcinogenesis initiated by peroxynitrite and promoted by TPA. Their activities were comparable to that of curcumin. These results suggested that 1, as well as 6 and 7, could be valuable as chemopreventive agents for chemical carcinogenesis. 相似文献
992.
Yoshinori Kashiwayama Midori Seki Akina Yasui Masashi Morita Masao Sakaguchi Tsuneo Imanaka 《Experimental cell research》2009,315(2):190-557
70-kDa peroxisomal membrane protein related protein (P70R/ABCD4) is a member of ATP-binding cassette (ABC) protein subfamily D. ABC subfamily D proteins are also known as peroxisomal ABC proteins. Therefore, P70R is thought to be a peroxisomal membrane protein. However, the subcellular localization of P70R is not extensively investigated. In this study, we transiently expressed P70R in fusion with HA (P70R-HA) in CHO cells and examined subcellular localization by immunofluorescence. Surprisingly, P70R-HA was localized to the endoplasmic reticulum (ER), not to peroxisomes. To examine the ER-targeting property of P70R, we expressed various NH2-terminal deletion constructs of P70R. Among the NH2-terminal deletion constructs, mutant proteins starting with hydrophobic transmembrane segment (TMS) were localized to ER, but the ones containing the NH2-terminal hydrophilic cytosolic domain were not. ABC subfamily D proteins destined for peroxisomes have NH2-terminal hydrophilic region adjacent to TMS1. However, only P70R lacks the region and is translated with NH2-terminal hydrophobic TMS1. Furthermore, attachment of the NH2-terminal hydrophilic domain to the NH2-terminus of P70R excluded P70R from the ER-targeting pathway. These data suggest that P70R resides in the ER but not the peroxisomal membranes, and the hydrophobic property of NH2-terminal region determines the subcellular localization of ABC subfamily D proteins. 相似文献
993.
Takahiro Fujimoto Keiko Doi Midori Koyanagi Toshiyuki Tsunoda Yasuo Takashima Yasuhiro Yoshida Senji Shirasawa 《FEBS letters》2009,583(3):568-14204
ZFAT (also known as ZNF406), originally identified as a candidate gene for autoimmune thyroid disease, encodes a zinc-finger protein, however, its function has not been elucidated. Here, we report that human ZFAT protein is expressed in peripheral B and T lymphocytes and a human acute T lymphoblastic leukaemia cell line, MOLT-4 cells. Intriguing is that mouse ZFAT expression in CD4+ lymphocytes is increased during blast formation. Furthermore, ZFAT-knockdown in MOLT-4 induces apoptosis via activation of caspases. These results suggested that ZFAT protein is a critical regulator involved in apoptosis and cell survival for immune-related cells. 相似文献
994.
995.
Erika Feltrin Stefano Campanaro Alexander D Diehl Elisabeth Ehler Georgine Faulkner Jennifer Fordham Chiara Gardin Midori Harris David Hill Ralph Knoell Paolo Laveder Lorenza Mittempergher Alessandra Nori Carlo Reggiani Vincenzo Sorrentino Pompeo Volpe Ivano Zara Giorgio Valle Jennifer Deegan née Clark 《BMC medical genomics》2009,2(1):1-8
996.
Mari Nomoto Midori Ogawa Kazumasa Fukuda Hiroshi Miyamoto Hatsumi Taniguchi 《Microbiology and immunology》2009,53(10):550-558
The mechanisms by which Mycobacterium tuberculosis survives and persists in phagocytic cells remain poorly understood. To study the question, a convenient and safe host-vector system is indispensable. In this study it has been shown that, in contrast with M . smegmatis strain mc2 155 which has been widely used for molecular analysis, M. smegmatis strain J15cs is able to survive even at day 6 post-infection in a murine macrophage cell line, J774. The survivability of J15cs was found to depend on the culture medium used for the bacteria prior to infection. Bacteria precultured on nutrient agar medium showed a high survivability and a characteristic cell wall ultrastructure. A plasmid vector, pYT923hyg, was developed from an Escherichia coli - mycobacterium shuttle vector pYT923 (previously constructed in our laboratory) to obtain three drug resistant genes (amp-, hyg- and km-resistant gene) and cloning sites in the km resistant gene. The vector pYT923hyg exerted no influence on in vitro growth of J15cs and intracellular survival in J774 cells, and was stably retained in J15cs after serial subculturing (three subcultures) in Luria-Bertani broth and at day 5 post-infection into J774 cells. Furthermore, using this system, the possibility of a relationship between some seemingly essential genes of M. tuberculosis and intracellular growth was demonstrated.
In this study, M. smegmatis strain J15cs and pYT923hyg were found to be capable of serving as an appropriate host-vector system for molecular study of the intracellular growth of M . tuberculosis in phagocytic cells; this system may be useful as a screening tool for M . tuberculosis genes. 相似文献
In this study, M. smegmatis strain J15cs and pYT923hyg were found to be capable of serving as an appropriate host-vector system for molecular study of the intracellular growth of M . tuberculosis in phagocytic cells; this system may be useful as a screening tool for M . tuberculosis genes. 相似文献
997.
998.
Midori Umekawa Cishan Li Takayuki Higashiyama Wei Huang Hisashi Ashida Kenji Yamamoto Lai-Xi Wang 《The Journal of biological chemistry》2010,285(1):511-521
Endo-M, an endo-β-N-acetylglucosaminidase from Mucor hiemalis, is a family 85 glycoside hydrolase. This enzyme is unique in that it can transfer en bloc the oligosaccharide of various types of N-glycans onto different acceptors, and thereby it enzymatically generates diverse glycoconjugates. In this study, we performed mutational and kinetic studies focusing on a key catalytic asparagine 175 of Endo-M. We have shown that most of the Asn-175 mutants had significantly diminished hydrolysis activity but acted as glycosynthases capable of using synthetic sugar oxazoline for transglycosylation. Our results confirm the critical role of this asparagine residue in promoting the formation of an oxazolinium ion intermediate in the first step of the substrate-assisted catalysis. Interestingly, the N175Q mutant was found to possess dramatically enhanced glycosynthase-like activity with sugar oxazoline in comparison with N175A and a transglycosidase-like activity with “natural” N-glycan as well. These results also implicated the significance of amide side chain in the asparagine 175 of Endo-M for promoting oxazoline transglycosylation in the second step of the catalysis. The highly efficient syntheses of glycopeptides/glycoproteins by N175Q combined with synthetic sugar oxazolines or natural N-glycan substrates were exemplified. In addition, we also identified several previously unknown residues that seem to play a role in the catalysis of Endo-M. 相似文献
999.
Masahiro Kasahara Mayumi Torii Akimitsu Fujita Kengo Tainaka 《The Journal of biological chemistry》2010,285(45):34765-34772
LOV domains function as blue light-sensing modules in various photoreceptors in plants, fungi, algae, and bacteria. A LOV/LOV protein (LLP) has been found from Arabidopsis thaliana (AtLLP) as a two LOV domain-containing protein. However, its function remains unknown. We isolated cDNA clones coding for an LLP homolog from tomato (Solanum lycopersicum) and two homologs from the moss Physcomitrella patens. The tomato LLP (SlLLP) contains two LOV domains (LOV1 and LOV2 domains), as in AtLLP. Most of the amino acids required for association with chromophore are conserved in both LOV domains, except that the amino acid at the position equivalent to the cysteine essential for cysteinyl adduct formation is glycine in the LOV1 domain as in AtLLP. When expressed in Escherichia coli, SlLLP binds FMN and undergoes a self-contained photocycle upon irradiation of blue light. Analyses using mutant SlLLPs revealed that SlLLP binds FMN in both LOV domains, although the LOV1 domain does not show spectral changes on irradiation. However, when Gly66 in the LOV1 domain, which is located at the position equivalent to the essential cysteine of LOV domains, is replaced by cysteine, the mutated LOV1 domain shows light-induced spectral changes. In addition, all four LOV domains of P. patens LLPs (PpLLP1 and PpLLP2) show the typical features of LOV domains, including the reactive cysteine in each. This study shows that plants have a new LOV domain-containing protein family with the typical biochemical and photochemical properties of other LOV domain-containing proteins such as the phototropins. 相似文献
1000.
Kazushige Ohtsuki Koji Kasahara Katsuhiko Shirahige Tetsuro Kokubo 《Nucleic acids research》2010,38(6):1805-1820