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111.
112.
Shinichi Mochizuki Naho Kanegae Koichi Nishina Yumi Kamikawa Kazunori Koiwai Hiroyasu Masunaga Kazuo Sakurai 《生物化学与生物物理学报:生物膜》2013,1828(2):412-418
Gene therapy is expected to treat various incurable diseases including viral infections, autoimmune disorders, and cancers. Cationic lipids (CL) have been used as carriers of therapeutic DNAs for gene therapy because they can form a complex with DNA and such a complex can be incorporated into cells and transport the bound DNA to cytosol. The CL/DNA complexes are called lipoplexes and categorized as a non-viral vector. Lipoplexes are often prepared by adding a neutral phospholipid dioleoylphosphatidylethanolamine (DOPE) to CL in order to enhance transfection. However, the role of DOPE is not fully understood. We synthesized a new CL having an ethylenediamine cationic head group, denoted by DA, and found that addition of DOPE to DA achieved a good efficiency, almost in the similar level of commonly used transfection reagent Lipofectamine 2000 (Invitrogen). The composition of DA:DOPE = 1:1 showed the highest efficiency. This lipoplex showed structural transition when pH was changed from 7 to 4, corresponding pH lowering in late endosome, while DOPE itself showed structural transition at more basic pH around 8. The present data showed that the DOPE/DA composition determines the structural transition pH and choosing a suitable pH, i.e., a suitable composition, is essential to increase the transfection efficiency. 相似文献
113.
Shinnosuke Machida Mai Tsubamoto Nobuo Kato Kazuo Harada Junko Ohkanda 《Bioorganic & medicinal chemistry》2013,21(14):4004-4010
Bivalent enzyme inhibitors, in which a surface binding module is linked to an active site binding module through a spacer, are a robust approach for site-selectively delivering a minimally-sized agent to a protein surface to regulate its functions, such as protein–protein interactions (PPIs). Previous research revealed that these agents effectively disrupt the interaction between farnesyltransferase (FTase) and the C-terminal region of K-Ras4B protein. However, the whole cell activity of these peptide-based agents is limited due to their low membrane permeability. In this study, we tested a peptidomimetic modification of these bivalent agents using a previously developed inhibitor, FTI-249, and evaluated their cell permeability and biological activity in cells. Confocal cell imaging using fluorescently-labeled agents showed that the peptidomimetic 3-BODIPY penetrated cells, while the peptide-based 1-BODIPY did not. Cell-based evaluation demonstrated that peptidomimetic 3 at a concentration of 100 μM inhibited HDJ-2 processing in cells, indicating that this peptidomimetic modification improves cell permeability, thus leading to enhanced whole cell activity of the bivalent compounds. 相似文献
114.
Kazuo Tanaka Hiroshi Okada Wataru Ohashi Jong-Hwan Jeon Kenichi Inafuku Yoshiki Chujo 《Bioorganic & medicinal chemistry》2013,21(10):2678-2681
The influence on the efficiencies of the triplet–triplet annihilation (TTA)-supported upconversion by oxygen under biomimetic conditions was investigated. From the solution containing the dendrimer complexes based on polyhedral oligomeric silsesquioxane (POSS)-core dendrimer with the Pt complex of octaethylporphyrin (PtOEP) and anthracene in PBS, the fluorescence emission of anthracene depending on the dissolved oxygen (DO) concentrations via the TTA-supported upconversion was obtained with the excitation light at 540 nm. In particular, we observed strong emission only under hypoxic conditions. In addition, it was found that the emission intensity via TTA-supported upconversion can be reversibly regulated by the DO concentrations in the solution. 相似文献
115.
116.
Izumi Yajima Mikio Nakamura Hidemasa Sakakibara Junichi Ide Tetsuya Yanai Kazuo Hayashi 《Bioscience, biotechnology, and biochemistry》2013,77(8):1755-1760
The aqueous extract of dried bonito (Katsuobushi) was distilled under reduced pressure. The resulting distillate with diethyl ether and the extract was separated into acidic, phenolic, basic and neutral fractions. The neutral fraction was further fractionated into ten sub-fractions by silica gel column chromatography. All these sub-fractions were analyzed by gas chromatography and gas chromatography-mass spectrometry.One hundred and sixty-five compounds were identified and 12 compounds were tentatively identified from the neutral fraction. Among them, 111 compounds were newly identified as flavor components of Katsuobushi. 相似文献
117.
The concomitant production of formic acid and pterin compounds from guanosine-5′-triphosphate (GTP) has been found in cell-free extracts of Serratia indica. Among the pterin compounds, l-threo-neopterin–the major Crithidia factor in S. indica–, a cyclic phosphate of neopterin (cNP), d-erythro-neopterin and 6-hydroxymethyl pterin were detected and isolated. Formate-14C elimination from GTP-8-14C was quantitatively distributed in the ethyl acetate layer in the ehyl acetate-hydrochloric acid partition system. Carbon 8 of GTP was released as formic acid. Enzymatic production of formate and cNP was linear for 2 hr at 37°C. Formate production was proportional to the enzyme concentration. The optimum pH for formate elimination was observed around pH 8.6. Optimum temperature for the production of formate and cNP was 50°C. The apparent Km value of GTP for formate production was 6.2×10?bm. Formate eliminating activity was activated by disodium phosphate but was inhibited by Mg2+ or AMP. Incorporation of GTP-U-14C into pterin compounds was also regulated with disodium phosphate. Effective incorporation into cNP and d-erythro-neopterin occurred in the presence of phosphate. When phosphate was omitted from the system, however, effective incorporation into 6-hydroxymethyl pterin was observed. The biosynthetic process of the Crithidia factors, i.e. l-threo-neopterin and cNP, from GTP in S. indica is also discussed. 相似文献
118.
Teruaki Shiroza Kazuo Furihata Toyoshige Endō Haruo Seto Noboru Ōtake 《Bioscience, biotechnology, and biochemistry》2013,77(5):1425-1427
Phosphatidylethanolamine N-methyltransferase, which catalyzes all the three-step methylation from phosphatidylethanolamine to phosphatidylcholine, was purified to homogeneity from the membrane fraction of Zymomonas mobilis. The purified enzyme exhibited a single band on SDS- polyacrylamide gel electrophoresis and its molecular weight was estimated to be 42,000 on comparison with those of marker proteins. The three activities dependent on phosphatidylethanolamine, phosphatidyl-N monomethylethanolamine and phosphatidyl-N Af-dimethylethanolamine of the purified enzyme showed similar pH profiles with an optimum of pH 8.5, and were enhanced in the same manner by Triton X-100 and l-cysteine. The maximal velocities of the three reactions for S-adenosyl-l-methionine were 0.04, 1.36 and 0.69 nmol/mg protein/min with apparent Michaelis constant values of 3.6, 1.9 and 3.9 fiM, respectively, indicating that the first-step methylation is rate-limiting for the pathway in the organism. 相似文献
119.
ω-Amino acid: pyruvate aminotransferase of Pseudomonas sp. F–126 catalyzes a transamination between various diamines and pyruvate, an exclusive amino acceptor. Based on a stoichiometric studies it was shown that one of the two amino groups of 1,2-diaminoethane, putrescine and cadaverine transaminated to pyruvate. The transamination between putrescine and pyruvate seemed to proceed by a ping-pong bi bi mechanism. Michaelis constants for putrescine and pyruvate were calculated to be 76.9 and 6.25 mm, respectively. 相似文献
120.