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2.
P.J.L. Derikx H.J.M. Op den Camp A.M. Wagner G. Straatsma L.J.L.D. van Griensven G.D. Vogels 《FEMS microbiology letters》1990,66(1-3):307-311
Abstract The respiratory pathways of Agaricus bisporus and Scytalidium thermophilum were studied. A. bisporus appeared to possess both a cyanide-sensitive and a cyanide-insensitive respiration while in S. thermophilum the cyande-insensitive respiration was absent. Growth experiments showed the ecological advantage for A. bisporus under conditions where cytochrome mediated respiration is inhibited. 相似文献
3.
J. T. Keltjens J. M. H. Hermans G. J. F. A. Rijsdijk C. Van der Drift G. D. Vogels 《Antonie van Leeuwenhoek》1988,54(3):207-220
F430 is the prosthetic group of the methylcoenzyme M reductase of methanogenic bacteria. The compound isolated from Methanosarcina barkeri appears to be identical to the one obtained from the only distinctly related Methanobacterium thermoautotrophicum. F430 is thermolabile and in the presence of acetonitrile or C10
in4
sup-
two epimerization products are obtained upon heating; in the absence of these compounds F430 is oxidized to 12, 13-didehydro-F430. The latter is stereoselectively reduced under H2 atmosphere to F430 by cell-free extracts of M. barkeri or M. thermoautotrophicum. H2 may be replaced by the reduced methanogenic electron carrier coenzyme F420.Abbreviations CH3S-CoM
methylcoenzyme M, 2-methylthioethanesulfonic acid
- HS-CoM
coenzyme M, 2-mercaptoethanesulfonic acid
- F430
Ni(II) tetrahydro-(12, 13)-corphin with a uroporphinoid (III) ligand skeleton
- 13-epi-F430 and 12,13-di-epi-F430
the 12, 13- and 12, 13-derivatives of F430
- 12, 13-didehydro-F430
F430 oxidized at C-12 and C-13
- coenzyme F420
7,8-didemethyl-8-hydroxy-5-deazaflavin derivative
- coenzyme F420H2
reduced coenzyme F420
- MV+
methylviologen semiquinone
- HPLC
high-performance liquid chromatography 相似文献
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Enzyme histochemical reactions in unfixed and undecalcified cryostat sections of mouse knee joints with special reference to arthritic lesions 总被引:4,自引:0,他引:4
The use of unfixed and undecalcified cryostat sections of mouse knee joints is described for the study of enzyme histochemical reactions. Non-inflamed knee joints and knee joints of mice with antigen induced arthritis have been used. Joints were embedded in gelatin and subsequently cut at low speed with a motor-driven cryostat fitted with a tungsten carbide knife at an obtuse angle (10 degrees). The sections were attached to transparent tape to keep the integrity of the tissue intact. The following histochemical reactions were carried out successfully: the tetrazolium salt reaction for dehydrogenase and reductase activity, the post-azo-coupling method for acid phosphatase and cathepsin B activity and the simultaneous azo-coupling method for esterase activity. In all cases the morphology and integrity of the sections were well kept and serial sections were obtained without any difficulty. Nonspecific staining of the tape did not occur. The localization of the final reaction product was meeting criteria for specific and precise histochemical methods with the exception of the metal salt method because of nonspecific staining of undecalcified bone. Cytophotometry of the final reaction product appeared to be reproducible and valid as demonstrated by reaction for glucose-6-phosphate dehydrogenase activity in synoviocytes from knee joints with induced arthritis. End point measurements as well as kinetic measurements of the formazan production were performed and linear relationships were found between the specific formazan formation and section thickness or incubation time, respectively. It is concluded that cryostat sections attached to transparent tape are an excellent tool for the study of the metabolism in tissues adjacent to bone matrix.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
7.
Structural characterization of tatiopterin, a novel pterin isolated from Methanogenium tationis 总被引:3,自引:0,他引:3
P C Raemakers-Franken F G Voncken J Korteland J T Keltjens C van der Drift G D Vogels 《BioFactors (Oxford, England)》1989,2(2):117-122
Cofactor extracts of Methanogenium tationis were screened for the presence of pterin-derivatives. Methanopterin, sarcinapterin and 7-methylpterin were absent, while 2-amino-4-hydroxy-pteridine and another blue fluorescent compound with a pterin spectrum were detected. The latter pterin was purified by ion exchange and reversed-phase column chromatography. The structure of this compound was elucidated by combining spectrophotometry, amino acid analysis and 1H-NMR spectroscopy. The pterin, which we named tatiopterin, was identified as an aspartyl derivative of sarcinapterin with a 7-proton instead of a 7-methyl group in the pterin moiety. The IUPAC name is: N-[-1'-(2'-amino-4'-hydroxy-7'-proton-6'-pteridinyl)ethyl]-4- [2',3',4',5'-tetrahydroxypent-1'-yl(5'----1')O-alpha- ribofuranosyl-5'-phosphoric acid]aniline, in which the phosphate group is esterified with alpha-hydroxyglutarylglutamylaspartic acid. 相似文献
8.
Involvement of an activation protein in the methanol:2-mercaptoethanesulfonic acid methyltransferase reaction in Methanosarcina barkeri. 总被引:3,自引:2,他引:1 下载免费PDF全文
P J Daas K A Gerrits J T Keltjens C van der Drift G D Vogels 《Journal of bacteriology》1993,175(5):1278-1283
Methanol:5-hydroxybenzimidazolylcobamide methyltransferase (MT1) is the first of two enzymes required for transfer of the methyl group of methanol to 2-mercaptoethanesulfonic acid in Methanosarcina barkeri. MT1 binds the methyl group of methanol to its corrinoid prosthetic group only when the central cobalt atom of the corrinoid is present in the highly reduced Co(I) state. However, upon manipulation of MT1 and even during catalysis, the enzyme becomes inactivated as the result of Co(I) oxidation. Reactivation requires H2, hydrogenase, and ATP. Ferredoxin stimulated the apparent reaction rate of methyl group transfer. Here we report that one more protein fraction was found essential for the overall reaction and, more specifically, for formation of the methylated MT1 intermediate. The more of the protein that was present, the shorter the delay of the start of methyl group transfer. The maximum velocity of methyl transfer was not substantially affected by these varying amounts of protein. This demonstrated that the protein was involved in the activation of MT1. Therefore, it was called methyltransferase activation protein. 相似文献
9.
Geertruida N. Jonges Ilse M. C. Vogels Klazina S. Bosch Koert P. Dingemans Cornelis J. F. Van Noorden 《Histochemistry and cell biology》1993,100(1):41-51
Metastases in rat liver were generated experimentally by intraportal injection of colon cancer cells to investigate the effects of cancerous growth on the metabolism of surrounding liver tissue. Maximum activities (capacity) of glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, lactate dehydrogenase, succinate dehydrogenase, alkaline phosphatase, 5-nucleotidase, xanthine oxidoreductase, purine nucleoside phosphorylase and adenosine triphosphatase have been determined. Two types of metastases were found, a small type surrounded by stroma and a larger type in direct contact with hepatocytes. Both types affected the adjacent tissue in a similar way suggesting that the interactions were not mediated by stroma. High capacity of the degradation pathway of extracellular purines released from dead cells of either tumours or host tissue was found in stroma and sinusoidal cells. Metastases induced both an increase in the number of Kupffer cells and proliferation of hepatocytes. The distribution pattern in the liver lobulus of most enzymes investigated did not change distinctly. However, activity of alkaline phosphatase, succinate dehydrogenase and phosphogluconate dehydrogenase was increased in hepatocytes directly surrounding metastases. These data imply that the overall metabolic zonation in liver lobuli is not dramatically disturbed by the presence of cancer cells despite the fact that various metabolic processes in liver cells are affected.In honour of Prof. Dr. Z. Lojda for his 65th birthday 相似文献
10.
G. D. Vogels C. van der Drift C. K. Stumm J. T. M. Keltjens K. B. Zwart 《Antonie van Leeuwenhoek》1984,50(5-6):557-567
Methanogenesis involves a novel set of coenzymes as one-carbon and electron carriers. Consequently, metabolic processes of
methanogens deviate from those present in non-methanogenic bacteria. Methanogenic bacteria can be classified on the basis
of substrate utilization. Group I (24 species) grows at the expense of hydrogen plus CO2 and/or formate and group II (7 species) uses methanol and/or acetate. Hydrogen-consuming methanogens are found as epi- or
endosymbionts of anaerobic ciliates. 相似文献