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71.
All known eukaryotic and some viral mRNA capping enzymes (CEs) transfer a GMP moiety of GTP to the 5'-diphosphate end of the acceptor RNA via a covalent enzyme-GMP intermediate to generate the cap structure. In striking contrast, the putative CE of vesicular stomatitis virus (VSV), a prototype of nonsegmented negative-strand (NNS) RNA viruses including rabies, measles, and Ebola, incorporates the GDP moiety of GTP into the cap structure of transcribing mRNAs. Here, we report that the RNA-dependent RNA polymerase L protein of VSV catalyzes the capping reaction by an RNA:GDP polyribonucleotidyltransferase activity, in which a 5'-monophosphorylated viral mRNA-start sequence is transferred to GDP generated from GTP via a covalent enzyme-RNA intermediate. Thus, the L proteins of VSV and, by extension, other NNS RNA viruses represent a new class of viral CEs, which have evolved independently from known eukaryotic CEs. 相似文献
72.
73.
Purification and characterization of a tuberculin-active substance from Mycobacterium bovis BCG 总被引:1,自引:0,他引:1
A new tuberculin-active substance, designated TAS-1D3, has been purified from the extract of Mycobacterium bovis BCG by precipitation at pH 4.2, ethanol fractionation, and column chromatography involving CM-cellulose, QAE-Sephadex A-25, Sephadex G-100, and Sephadex G-75. TAS-1D3 was homogeneous in polyacrylamide gel electrophoresis and positive in both Coomassie brilliant blue and periodic acid-Shiff staining, suggesting that TAS-1D3 is a glycoprotein. The molecular weight of TAS-1D3 was estimated to be 26,000 by gel filtration. In amino acid analysis, TAS-1D3 was distinctive in having proline as a dominant amino acid, and in that it lacked basic amino acids, sulfur-containing amino acids and aromatic amino acids. Moreover, TAS-1D3 was almost devoid of absorption at around 280 nm. In guinea pigs sensitized with BCG vaccine, the tuberculin activity of TAS-1D3 was about forty times more potent than that of purified protein derivative (PPD). 相似文献
74.
Hasegawa T Bando A Tsuchiya K Abe S Okamoto M Kirima K Ueno S Yoshizumi M Houchi H Tamaki T 《Biochimica et biophysica acta》2004,1670(1):19-27
The nonenzymatic and enzymatic formation of reactive oxygen species (ROS) from LY83583 (6-anilino-5,8-quinolinequinone) was investigated by electron paramagnetic resonance (EPR) spectroscopy. In the presence of thiol compounds such as glutathione and L-cysteine, LY83583 underwent a one-electron reduction due to low redox potential (-0.3+/-0.01 V vs. SCE), followed by formation of LY83583 semiquinone anion radical. This species was characterized by EPR spectroscopy under an argon atmosphere at neutral pH. Under an aerobic condition, this species interacts with molecular oxygen to form a superoxide anion radical. GSH-conjugated LY83583 was also identified by NMR and FAB-MS. When LY83583 was applied to PC12 cells, ROS formation was completely inhibited by both the flavoenzyme inhibitor DPI and the DT-diaphorase inhibitor dicumarol. On the other hand, ROS generation occurred independent of intracellular GSH level. These results indicate that LY83583 can generate ROS both enzymatically and nonenzymatically, although the enzymatic formation is dominant over the nonenzymatic system in PC12 cells. 相似文献
75.
We have reported the existence of a phosphonoglycosphingolipid containing a pyruvylated galactose, FGL-IIb, in nerve fibers of Aplysia kurodai (Araki, S., Abe, S., Ando, S., Kon, K., Fujiwara, N. & Satake, M. (1989) J. Biol. Chem. 264, 19922-19927). We have now isolated two other pyruvylated galactose-containing phosphonoglycosphingolipids, named FGL-V and FGL-IIa, from the nervous tissue of Aplysia, and characterized them as [3,4-O-(S-1-carboxyethylidene)]Gal beta 1----3GalNAc alpha 1----3[6'-O-(2- aminoethylphosphonyl)Gal alpha 1----2] (2-aminoethylphosphonyl----6) Gal beta 1----4Glc beta 1----1 ceramide and [3,4,O-(S-1-carboxyethylidene)] Gal beta 1----3GalNAc alpha 1----3[6'-O-(2-aminoethylphosphonyl)Gal alpha 1----2]Gal beta 1----4Glc beta 11----ceramide, respectively. Their major aliphatic components are palmitic acid, octadeca-4-sphingenine and anteisononadeca-4-sphingenine. Thus, the nervous system of Aplysia contains several pyruvylated phosphonoglycolipids. 相似文献
76.
Hiroshi Abe Takeshi Shimoda Jun Ohnishi Soichi Kugimiya Mari Narusaka Shigemi Seo Yoshihiro Narusaka Shinya Tsuda Masatomo Kobayashi 《BMC plant biology》2009,9(1):97
Background
The western flower thrips (Frankliniella occidentalis [Pergande]) is one of the most important insect herbivores of cultivated plants. However, no pesticide provides complete control of this species, and insecticide resistance has emerged around the world. We previously reported the important role of jasmonate (JA) in the plant's immediate response to thrips feeding by using an Arabidopsis leaf disc system. In this study, as the first step toward practical use of JA in thrips control, we analyzed the effect of JA-regulated Arabidopsis defense at the whole plant level on thrips behavior and life cycle at the population level over an extended period. We also studied the effectiveness of JA-regulated plant defense on thrips damage in Chinese cabbage (Brassica rapa subsp. pekinensis). 相似文献77.
Effects of lactoferrin and lactoperoxidase‐containing food on the oral microbiota of older individuals 下载免费PDF全文
Manabu Nakano Hiroyuki Wakabayashi Hirosuke Sugahara Toshitaka Odamaki Koji Yamauchi Fumiaki Abe Jin‐Zhong Xiao Kohji Murakami Kentaro Ishikawa Shouji Hironaka 《Microbiology and immunology》2017,61(10):416-426
78.
In an attempt to evaluate effects of liver injury and roles of iron metabolism on systemic fungal infection, experimental systemicCandida infection was produced in mice with galactosamine-induced liver injury. Survival rate and extent of fungal lesion are compared between mice with liver injury (Group 1) and ones without liver injury (Group 2). Median survival was 7 and 18 days in Group 1 and 2 respectively after 21 days observation. Mortality rate of Group 1 was significantly higher (P=0.05) than that of Group 2. This difference was reflected to the extent of fungal lesions in that they were extensive and disseminated, involving the multiple organs in Group 1 but predominantly localized to the kidneys in Group 2. UIBC (unbound iron binding capacity) and TIBC (total iron binding capacity), i.e., serum transferrin as well as serum iron levels were significantly lower in Group 1 as compared with those in Group 2. These results indicate that hepatic injury promotesCandida infectionin vivo and suggest that increased susceptibility toCandida in the presence of liver injury is, at least partially, attributable to low UIBC and/or TIBC. 相似文献
79.
The three-dimensional structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica, has been determined in solution at pH 6.8 and 25 degrees C by (1)H and (15)N NMR spectroscopy. The main body (Glu13-Asp97) of oryzacystatin-I is well-defined and consists of an alpha-helix and a five-stranded antiparallel beta-sheet, while the N- and C-terminal regions (Ser2-Val12 and Ala98-Ala102) are less defined. The helix-sheet architechture of oryzacystatin-I is stabilized by a hydrophobic cluster formed between the alpha-helix and the beta-sheet and is considerably similar to that of monellin, a sweet-tasting protein from an African berry, as well as those of the animal cystatins studied, e.g., chicken egg white cystatin and human stefins A and B (also referred to as human cystatins A and B). Detailed structural comparison indicates that oryzacystatin-I is more similar to chicken cystatin, which belongs to the type-2 animal cystatins, than to human stefins A and B, which belong to the type-1 animal cystatins, despite different loop length. 相似文献
80.
Matsusaki H Abe H Taguchi K Fukui T Doi Y 《Applied microbiology and biotechnology》2000,53(4):401-409
Pseudomonas sp. 61-3 accumulated a blend of poly(3-hydroxybutyrate) [P(3HB)] homopolymer and a random copolymer consisting of 3-hydroxyalkanoate
(3HA) units of 4–12 carbon atoms. The genes encoding β-ketothiolase (PhbARe) and NADPH-dependent acetoacetyl-CoA reductase (PhbBRe) from Ralstoniaeutropha were expressed under the control of promoters for Pseudomonas sp. 61-3 pha locus or R. eutropha phb operon together with phaC1
Ps gene (PHA synthase 1 gene) from Pseudomonas sp. 61-3 in PHA-negative mutants P. putida GPp104 and R. eutropha PHB−4 to produce copolyesters [P(3HB-co-3HA)] consisting of 3HB and medium-chain-length 3HA units of 6–12 carbon atoms. The introduction of the three genes into
GPp104 strain conferred the ability to synthesize P(3HB-co-3HA) with relatively high 3HB compositions (up to 49 mol%) from gluconate and alkanoates, although 3HB units were not incorporated
at all or at a very low fraction (3 mol%) into copolyesters by the strain carrying phaC1
Ps gene only. In addition, recombinant strains of R. eutropha PHB−4 produced P(3HB-co-3HA) with higher 3HB fractions from alkanoates and plant oils than those from recombinant GPp104 strains. One of the recombinant
strains, R. eutropha PHB−4/pJKSc46-pha, in which all the genes introduced were expressed under the control of the native promoter for Pseudomonas sp. 61-3 pha locus, accumulated P(3HB-co-3HA) copolyester with a very high 3HB fraction (85 mol%) from palm oil. The nuclear magnetic resonance analyses showed that
the copolyesters obtained here were random copolymers of 3HB and 3HA units.
Received: 12 July 1999 / Received revision: 1 October 1999 / Accepted: 2 October 1999 相似文献