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41.
Rogacheva SM Denisova SA Shul'gin SV Somov AIu Kuznetsov PE 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2008,48(4):474-480
The study of the action of the electromagnetic radiation (EMR) of low intensity (10 microW/cm2) in the range of frequencies 120-170 GHz at the test-reaction of Infusoria Paramecium caudatum was carried out. The resonant character of the effects was established. The EMR action at 156.6 and 161.3 GHz caused the increase of infusorians mobility, the action at frequencies 151.8, 155.7, 167.1 GHz caused the mobility reduction. Isolated and combined with EMR effects of nicotine (10(-4)-10(-15) mol/l) and antimicrobial drug metronidazole (10(-5), 10(-8), 10(-9) mol/l) were investigated. The radiation at the frequency 167.1 GHz was shown to reduce the effect of nicotine (10(-9) mol/l) and to enhance the effect of metronidazole (10(-9) mol/l). This phenomenon may be explained by different effects of the substances in low concentration at the water hydrogen bonds net structure. 相似文献
42.
Cherkashyna DV Tkachova OM Somov OIu Semenchenko OA Lebedyns'kyĭ OS Petrenko OIu 《Ukrainski? biokhimicheski? zhurnal》2008,80(2):101-105
The influence of oxidative phosphorylation uncoupler 2,4-dinitrophenol (DNP) presence in preserving solution on the rat liver respiratory activity and ATP content after 18 h of hypothermic storage (HS) and following normothermic reperfusion (NR) was investigated. DNP presence on the HS stage led to decrease of ATP level as compared with the control. After DNP removal during NR the gradual recovery of oxidative phosphorylation coupling occurred. This fact resulted in improvement of mitochondrial functional state (V4 respiration rate decrease, respiratory control and ATP level increase). 相似文献
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We demonstrate for the first time that the pathogenic bacteria Yersinia pseudotuberculosis and Listeria monocytogenes (pathogens of saprozoonoses) are capable of chemolithoautotrophic assimilation of CO2. Low temperature is favorable for better absorption of CO2 by these bacteria; this is supported by increased enzymatic activity of carbonic anhydrase acting as the supplier of the substrate to the site of carboxylation. Data of radioisotopic methods indicate that assimilated labeled carbon of CO2 is incorporated into all major cell biopolymers. The bacteria can utilize not only CO2, but also other C1-compounds for biosynthesis. 相似文献
45.
This study examined the application of previously characterized microparticles composed of hyaluronan (HA) and chitosan hydroglutamate (CH) as well as novel microparticles consisting of both polymers (HA/CH) to improve the nasal delivery of a model drug. The rabbit bioavailabilities of gentamicin incorporated in HA, CH, and HA/CH microparticles were increased 23-, 31-, and 42-fold, respectively, compared with the control intranasal solution of gentamicin, indicating that all test microparticles were retained for longer periods on the nasal mucosa of the rabbits as supported by previous in vitro dissolution as well as frog palate mucoadhesion studies, thereby improving drug absorption. The higher bioavailabilities of CH-based formulations (CH and HA/CH) suggest the penetration-enhancing effects of CH may also be partially responsible for the improvement. A model was developed, based on a glass impinger device, to deliver dry powder formulations reproducibly onto the surface of cultured cell monolayers. In vitro permeability and fluorescence microscopy studies on the tight junctions of the 16HBE14o- cell lines further confirmed the ability of CH-based formulations to enhance penetration. Furthermore, the in vitro absorption profile from cell culture studies was consistent with those determined from in vivo studies. The complementary effect from the mucoadhesive nature of HA coupled with the penetration-enhancing effects of CH makes the novel HA/CH formulation a promising nasal delivery system. 相似文献
46.
Martin Irestedt Knud A J?nsson Jon Fjelds? Les Christidis Per GP Ericson 《BMC evolutionary biology》2009,9(1):235
Background
The birds-of-paradise (Paradisaeidae) form one of the most prominent avian examples of sexual selection and show a complex biogeographical distribution. The family has accordingly been used as a case-study in several significant evolutionary and biogeographical syntheses. As a robust phylogeny of the birds-of-paradise has been lacking, these hypotheses have been tentative and difficult to assess. Here we present a well supported species phylogeny with divergence time estimates of the birds-of-paradise. We use this to assess if the rates of the evolution of sexually selected traits and speciation have been excessively high within the birds-of-paradise, as well as to re-interpret biogeographical patterns in the group. 相似文献47.
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On the basis of epidemiological analysis carried out at the period of 1940-1987, a decrease in tick-borne encephalitis (TBE) morbidity was registered; at the same time time the disease invariably took, as before, a clinically severe course. The most dangerous foci of TBE were found to be located in the southern Okhotsk region grown with dark coniferous forests. The subsiding and activation of the natural foci of TBE in different regions of the territory were established and some heretofore unknown foci in southern regions of the Maritime Territory were found. Ixodes mites inhabiting the Maritime Territory were shown to have a low level of virus carriership, thus causing the low level of population immunity to TBE virus. Combined foci of TBE and Powassan encephalitis were found. 相似文献
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