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1.
2.
Pseudomonas cepacia MBA4 able to utilize monobromoacetic acid as a sole source of carbon and energy was isolated from soil by enrichment culture. In batch culture the ability to utilize the substrate was conferred by a single halidohydrolase-type dehalogenase which demonstrated a high activity towards the enrichment substrate. The purified enzyme, designated as dehalogenase IVa by activity-stain polyacrylamide gel electrophoresis, had a relative molecular weight of 45,000 and was comprised of two electrophoretically identical subunits with relative molecular weights of 23,000. Dehalogenase IVa demonstrated isomer specificity, being active towards the L-isomer of 2-monochloropropionic acid only. The significance of activity-stain polyacrylamide gel electrophoresis in characterizing dehalogenases and their ubiquitous distribution among bacterial genera are discussed.Abbreviations MCA
Monochloroacetic acid
- DCA
dichloroacetic acid
- MBA
monobromoacetic acid
- 2MPCA
2-monochloropropionic acid
- 2MBPA
2-monobromopropionic acid 相似文献
3.
M. V. Baev L. V. Chistoserdova B. M. Polanuer V. E. Sterkin M. Y. Kiriukhin Y. D. Tsygankov 《Archives of microbiology》1992,158(2):145-148
The ribulose monophosphate cycle methylotroph Methylobacillus flagellatum was grown under oxyturbidostat conditions on mixtures of methanol and formaldehyde. Formaldehyde when added at low concentration (50 mg/l) increased the methanol consumption and the yield of biomass. The presence of 150–300 mg/l of formaldehyde resulted in an increase of the growth rate from 0.74 to about 0.79–0.82 h-1. The presence of 500 mg/l of formaldehyde in the inflow decreased culture growth characteristics. Activities of methanol dehydrogenase and enzymes participating in formaldehyde oxidation and assimilation were measured. The enzymological profiles obtained are discussed.Abbreviations MDH
methanol dehydrogenase
- NAD-linked FDDH
NAD-linked formaldehyde dehydrogenase
- DLFDDH
dye-linked formaldehyde dehydrogenase
- DLFDH
dye-linked formate dehydrogenase
- GPDH
glucose-6-phosphate dehydrogenase
- PGDH
6-phosphogluconate dehydrogenase
- RuMP cycle
ribulose monophosphate cycle 相似文献
4.
The Src family of tyrosine protein kinases represent an expanding class of closely related intracellular enzymes that participate in the signal transduction pathways of a variety of surface receptors. One of the more surprising aspects of the information relating Src protein kinases to receptor signaling is the apparent diversity of receptor types with which the Src-related enzymes are reported to interact physically or functionally. Traditional biochemical and genetic approaches have yielded much information regarding the interactions between the Src tyrosine protein kinases and other cellular proteins in defined cell types, and emerging technologies, most notably homologous recombination in embryonal stem cells to achieve gene "knockouts," are providing new insights into the participation of the Src-related gene products in signal transduction and development. 相似文献
5.
J. Nešvera M. Pátek J. Hochmannová E. Chibisova I. Serebrijski Y. Tsygankov A. Netrusov 《Applied microbiology and biotechnology》1991,35(6):777-780
Summary
Brevibacterium methylicum is a newly isolated Gram-positive facultatively methylotrophic bacterium that uses the NAD+-dependent methanol dehydrogenase for methanol oxidation and assimilates its carbon via the ribulose monophosphate cycle. Protoplasts prepared by lysozyme treatment of B. methylicum cells grown in the presence of glycine were transformed by plasmid shuttle vectors pCEM500 (16.5 kb; Smr/Spr, Kmr/Gmr) and pEC71 (7.1 kb; Kmr/Nmr) constructed on the basis of B. lactofermentum plasmid pAM330 and replicating in Escherichia coli and in amino-acid-producing coryneform bacteria. The resistance markers were found to be expressed in B. methylicum and autonomous plasmid DNAs of various size were isolated from the transformants. The presence of the pAM330 replicon in these plasmids was demonstrated by DNA-DNA hybridization experiments.
Offprint requests to: J. Nevera 相似文献
6.
Iu D Tsygankov A Iu Chistoserdov S M Kazakova 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1985,(2):3-14
Cloning of methylotropic and other Gram negative bacteria's genes was performed using vectors derived from IncP4 plasmids. Plasmids, such s RSF1010 are 8.8 kb in length, have a high copy number and broad host range and can be mobilized efficiently by a number of conjugative plasmids. IncP4 plasmids have relatively few restriction enzyme's targets suitable for cloning. In this paper the construction of versatile and special purpose IncP4 vectors available for cloning DNA into broad range of bacterial species are described. The seria of versatile vectors involves the transposon containing plasmid and two-replicon vectors.In genetic construction of special vector for direct cloning of restriction fragments the genetic regulation elements of Tn 1 were used. On the base of IncP4 replicon special vectors for construction of bank genes (cosmids) and the vectors for cloning of regulation sequence were also constructed. 相似文献
7.
Nielsen J; Peixoto AA; Piccin A; Costa R; Kyriacou CP; Chalmers D 《Molecular biology and evolution》1994,11(6):839-853
The region of the clock gene period (per) that encodes a repetitive tract
of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran
species both within and outside the Drosophilidae. All the non-
Drosophilidae sequences in this region are short and present a remarkably
stable picture compared to the Drosophilidae, in which the region is much
larger and extremely variable, both in size and composition. The
accelerated evolution in the repetitive region of the Drosophilidae appears
to be mainly due to an expansion of two ancestral repeats, one encoding a
Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and
asparagine or threonine. In some drosophilids the expansion involves a
duplication of the pentapeptide sequence, but in Drosophila pseudoobscura
both the dipeptide and the pentapeptide repeats are present in larger
numbers. In the nondrosophilids, however, the pentapeptide sequence is
represented by one copy and the dipeptide by two copies. These observations
fulfill some of the predictions of recent theoretical models that have
simulated the evolution of repetitive sequences.
相似文献
8.
Anti-CD3 antibodies are directed to the nonpolymorphic part of the T cell receptor complex and may activate human peripheral T cells. Under some circumstances crosslinked anti-CD3 has been described to augment the proliferative response. Here we demonstrate that crosslinking of stimulatory anti-CD3 antibodies by anti-IgG in cell suspension abolishes their effect on proliferation of human resting peripheral T cells in the presence of PMA and/or IL-2. This effect was observed within a wide range of anti-CD3 concentrations (1 ng/ml to 1 microgram/ml) independent of the presence of monocytes. The inhibition was not due to the induction of cell death, since cells remained propidium iodide-negative after treatment. Protein-tyrosine phosphorylation after anti-CD3 crosslinking was more pronounced than in the presence of noncrosslinked anti-CD3. This indicates that the signal was transmitted after anti-CD3 crosslinking, however, it was unable to induce T cell proliferation. Reduced IL-2 receptor expression after anti-CD3 crosslinking and the inability of exogenous IL-2 to restore the proliferative response might indicate a reduced susceptibility to IL-2 as a reason for the described phenomenon. 相似文献
9.
Taro Suzuki Anatoly A. Tsygankov Jun Miyake Yutaka Tokiwa Yasuo Asada 《Biotechnology letters》1995,17(4):395-400
Summary Effect of pH of culture media on intracellular accumulation of poly-(hydroxybutyrate) (PHB) by a non-sulfur photosynthetic bacterium, Rhodobacter sphaeroides strain RV was studied in pH-stat cultures. Sub-optimal pH for growth, 8.0 or 8.5 gave the higher content of PHB rather than optimal pH 7.5 for growth. These results show that growth and PHB accumulation of the bacteria can be controlled by pH of culture media. 相似文献
10.
Evolutionary origin of human and primate malarias: evidence from the circumsporozoite protein gene 总被引:8,自引:1,他引:7
We have analyzed the conserved regions of the gene coding for the
circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria
parasite. The closest evolutionary relative of P. falciparum, the agent of
malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is
consistent with the hypothesis that P. falciparum is an ancient human
parasite, associated with humans since the divergence of the hominids from
their closest hominoid relatives. Three other human Plasmodium species are
each genetically indistinguishable from species parasitic to nonhuman
primates; that is, for the DNA sequences included in our analysis, the
differences between species are not greater than the differences between
strains of the human species. The human P. malariae is indistinguishable
from P. brasilianum, and P. vivax is indistinguishable from P. simium; P.
brasilianum and P. simium are parasitic to New World monkeys. The human P.
vivax-like is indistinguishable from P. simiovale, a parasite of Old World
macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are
evolutionarily recent human parasites, the first two at least acquired only
within the last several thousand years, and perhaps within the last few
hundred years, after the expansion of human populations in South America
following the European colonizations. We estimate the rate of evolution of
the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year.
The divergence between the P. falciparum and P. reichenowi lineages is
accordingly dated 8.9 Myr ago. The divergence between the three lineages
leading to the human parasites is very ancient, about 100 Myr old between
P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between
P. falciparum and the other two.
相似文献