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1.
2.
Drainage melioration in the Polesye resulted in a sharp increase in the number of tundra vole (Microtus oeconomus Pall.) which quickly included into the parasitocenosis of the drained land. There were found 26 parasitic and nonparasitic species of Gamasoidea, 3 species of Ixodidae and 2 species of Trombiculidae, 10 species of Aphaniptera, 3 species of Anoplura but there was found no species specific only for the tundra vole. All found parasites occur on many hosts. This explains wide parasitic links of the tundra vole with other homothermic animals which especially extensive with the bank vole and it may have important consequences for epizootiology of tularemia and tick-borne encephalitis. 相似文献
3.
Kulikov AV Bogatyrenko VR Likhtenshteĭn GI Allakhverdiev SI Klimov VV Shuvalov VA Krasnovskiĭ AA 《Biofizika》1983,28(3):357-362
The influence of Mn on saturation curves of ESR spectra of Ph(-) and P(+)(680) at 1-200K in samples with different content of Mn has been studied. An analysis of these data and those on photoinduced changes of fluorescence yield of chlorophyll leads to the conclusion that the Mn-containing centre in Photosystem 2 is a cluster of 4 Mn atoms, two of which can be replaced by Mg(2+) or any other divalent metal. The distances between Mn Na Ph as well as between Mn and P(680) have been estimated. 相似文献
4.
Activity of nucleoside di- and nucleoside triphosphates metabolism enzymes in tissues of rats gamma-irradiated by a dose of 30 Gy was studied 0.5, 1, 3, 6 and 24 hours after the radiation effect. It is shown that the nucleoside monophosphate kinase activity of the liver and brain is enhanced almost at all stages of the studies and the nucleoside diphosphate kinase activity is inhibited. A significant but reversible decrease of the nucleoside monophosphate kinase activity is observed in the liver 3 h later. By an end of the first day after irradiation the nucleoside mono- and nucleoside diphosphate kinase activities increase significantly both in the liver and brain. 相似文献
5.
E R Nagiev V V Tsybul'ski? I V Savitski? I N Litovchenko 《Ukrainski? biokhimicheski? zhurnal》1990,62(2):114-118
The X-ray irradiation in a dose of 450 R is shown to decrease the monoaminoxidase activity in the cell fractions of the mucous membrane of small intestine as against the fractions of the stomach mucosa. The administration of pyridoxalphosphate to the irradiated rabbits increases the monoaminoxidase activity in the fraction and subfractions of small intestine mucosa mitochondria, but the enzyme activity being compared with the control group has a tendency to decrease. 相似文献
6.
The ATP-binding-cassette transmembrane transporters (ABC transporters)
known from vertebrates belong to four major subfamilies: (1) the P-
glycoproteins (Pgp); (2) the cystic fibrosis transmembrane conductance
regulators (CFTR); (3) the Tap proteins encoded with the major
histocompatibility complex of mammals; and (4) the peroxisomal membrane
proteins. Both Pgp and CFTR have a structure suggesting a past internal
gene duplication; a phylogenetic analysis indicated that these duplications
occurred independently, while an independent tandem gene duplication
occurred in the case of the Tap family. Both the Pgp and Tap proteins show
evidence of relationship to bacterial ABC transporters lacking internal
duplication, and both are significantly more closely related to the HlyB
and MsbA families of transporters from purple bacteria than they are to ABC
transporters from nonpurple bacteria. The simplest hypothesis to explain
this observation is that eukaryotic Pgp and Tap genes are descended from a
mitochondrial gene or genes that were subsequently translocated to the
nuclear genome. The Pgp genes of eukaryotes are characterized by a
remarkable degree of convergent evolution between the ATP-binding cassettes
of their N- terminal and C-terminal halves, whereas no such convergence is
seen between the two halves of CFTR genes or between the duplicated Tap
genes. Exon 13 of the CFTR gene, which encodes a putative regulatory domain
not found in other ABC transporters apart from CFTR, showed high levels of
both synonymous and nonsynonymous difference in comparisons among different
mammalian species, suggesting that this region is a mutational hot spot.
相似文献
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X Xiao G Hintermann AL Demanin J Piret 《Journal of industrial microbiology & biotechnology》1996,16(4):261-262
Streptomyces glaucescens is shown to possess -lactamase activity which is inhibitable by clavulanate. This is important in regard to its use as a cloning host for enzymes of \-lactam biosynthesis. 相似文献
9.
ERIC S. BONO PATRICK SMOLINSKI AL CASAGRANDA JUNDE XU 《Computer methods in biomechanics and biomedical engineering》2013,16(2):125-131
The Shear-slip Mesh Update Method (SSMUM) is being used in flow simulations involving large but regular displacements of one or more boundaries of the computational domain. We follow up the earlier discussion of the method with notes on practical implementation aspects. In order to establish a benchmark problem for this class of flow problems, we define and report results from a two-dimensional viscous flow around a rotating stirrer in a square chamber. The application potential of the method is demonstrated in the context of biomedical design problem, as we perform an analysis of blood flow in a centrifugal left ventricular assist device, or blood pump, which involves a rotating impeller in a non-axisymmetric housing. 相似文献
10.