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641.
AA Karelin MM Philippova EV Karelina BN Strizhkov GA Grishina IV Nazimov VT Ivanov 《Canadian Metallurgical Quarterly》1998,4(3):211-225
In 1995 at a sea-farm in Ireland, Atlantic salmon Salmo salar smolts were introduced in the spring and autumn into 2 marine rearing sites, one with and one without recent histories of neurologic disease and mass mortality believed to be due to parasitic encephalitis. In order to monitor disease, determine the onset and anatomic distribution of parasites and encephalitis, and determine the ultrastructure and identity of the parasite, randomly selected smolts were necropsied from both sites at intervals of 1 to 3 d for periods of 1 to 2 mo, and clinical signs and cumulative mortalities were monitored. The prevalences of parasites and encephalitis were assessed by light microscopy, and sections of brain were examined by transmission electron microscopy. No clinical signs of neurologic disease were observed, but parasites and encephalitis were detected in smolts from both sites, with prevalences of each that were significantly greater in smolts from the site with recent disease. Based on light microscopy, the parasite was first detected in smolts sampled at 26 d post-introduction. Parasites were detected with significantly greater frequency in the optic tectum of the mesencephalon than in the diencephalon, metencephalon, and myelencephalon, and were not detected in the telencephalon. Foci of non-suppurative encephalitis were detected with significantly greater frequency in the myelencephalon than in each of the other 4 anatomic subdivisions. In each anatomic subdivision the prevalence of encephalitis was significantly greater than that of parasitic infection. The ultrastructure of the parasite was consistent with that of a histozoic presporogonic multicellular developmental stage of a myxosporean, characterized by intercellular branching tubular structures containing generative cells arranged individually or in cell-in-cell doublets. Parasitic stages were located between bundles of axons, with compression of axons along segments of their plasmalemma. No mature spores were detected. 相似文献
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Weeks W. IV Blahut R.E. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1998,44(3):1193-1203
We define a checkerboard code as a two-dimensional binary code that satisfies some constraint, e.g., every binary one must be surrounded by eight zeros, and then investigate the capacity for each of several different constraints. Using a recursive construction we develop a series of loose bounds on the capacity. These bounds, in turn, lead to conjecturally precise estimates of the capacity by the use of a numerical convergence-speeding technique called Richardson extrapolation. Finally, using the value of the capacity, we define and compute a measure of coding gain which allows us to compare checkerboard codes to simple coding schemes 相似文献
645.
KENNETH J. PRUSA EDGAR CHAMBERS IV JANE A. BOWERS FRANK CUNNINGHAM A. D. DAYTON 《Journal of food science》1981,46(6):1684-1686
Taste panel scores, Instron measurements, and thiamin, fat, and moisture contents from microwave and conventionally cooked baking hens, injected with distilled water and papain solution (0.001 and 0.002%) were determined. Moisture, fat, and thiamin contents and cooking losses were not significantly affected by treatment. For papain injected samples, Instron measurements were less than those for uninjected samples when fibers were separated against the grain. Papain injected samples were more tender and mealier than uninjected samples. Roast chicken flavor was unaffected, but off-flavor increased in the papain-injected samples. Generally, cooking methods did not affect sensory scores. 相似文献
646.
SG Vorsanova IA Demidova Ulas VYu IV Soloviev LZ Kazantzeva Yurov YuB 《Canadian Metallurgical Quarterly》1996,8(1):187-189
Rett syndrome (RS) is a progressive encephalopathy restricted to the female sex. In the present study we investigated 30 females and one male with RS by cytogenetic and molecular-cytogenetic methods. We failed to identify any chromosomal rearrangements within the female groups and no correlation between fra(X)(p22) and RS in either the female group or the male. The boy with RS has karyotype 46,XY/47,XXY with abnormal cell clone (47,XXY) in 6-12% of his lymphocytes (revealed by fluorescence in situ hybridization analysis (FISH) of interphase cells with chromosome X-specific DNA probe). Our results indicated a possible connection between RS and X-chromosome replication disturbance. A late-replicating X-chromosome with a specific banding pattern (type 'C') has been observed in RS patients only. We propose to analyse the X-chromosome replication pattern as a test for confirmation of RS at preclinical diagnosis. 相似文献
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Open field tests were made on 489 white male rats to distinguish subgroups by baseline higher nervous activity (HNA) to study the effects of cerebrolysin (EBEVE, Austria) on relationships between neuronal activity and cerebral blood supply in normal cerebral circulation (CC) and in acute brain ischemia. Local CC and EEG were measured by laser doppler flowmeter and read from the same point gauge. CC/EEG index was calculated. Cerebrolysin was injected i.p. in a dose 0.3 ml/100 g body mass. Brain ischemia was provoked by occlusion of the common carotid arteries. Neurological symptoms were estimated according to the McGrow scale. Also, 24-h lethality was registered. It was confirmed that cerebrolysin, as an active nootrop, enhances EEG. This effect takes place both in intact and brain ischemia rats. It was also found that cerebrolysin has different effectiveness dependent on the animal's behavior in the open field test, that blood supply to the brain does not increase in cerebrolysin-activated HNA. In stable circulation, this was compensated due to cerebral metabolic reserve, but in intensive EEG activation, recorded by CC/EEG index, cerebrolysin reduces cerebral blood supply aggravating acute brain ischemia. 相似文献
649.
IV Oradovskaia TT Radzivil VT Antipin IuN Levenko 《Canadian Metallurgical Quarterly》1997,37(6):843-854
We have previously shown that intact plants and cultured plant cells can metabolize and detoxify formaldehyde through the action of a glutathione-dependent formaldehyde dehydrogenase (FDH), followed by C-1 metabolism of the initial metabolite (formic acid). The cloning and heterologous expression of a cDNA for the glutathione-dependent formaldehyde dehydrogenase from Zea mays L. is now described. The functional expression of the maize cDNA in Escherichia coli proved that the cloned enzyme catalyses the NAD(+)- and glutathione (GSH)-dependent oxidation of formaldehyde. The deduced amino acid sequence of 41 kDa was on average 65% identical with class III alcohol dehydrogenase from animals and less than 60% identical with conventional plant alcohol dehydrogenases (ADH) utilizing ethanol. Genomic analysis suggested the existence of a single gene for this cDNA. Phylogenetic analysis supports the convergent evolution of ethanol-consuming ADHs in animals and plants from formaldehyde-detoxifying ancestors. The high structural conservation of present-day glutathione-dependent FDH in microorganisms, plants and animals is consistent with a universal importance of these detoxifying enzymes. 相似文献
650.
GI Klebanov IuO Teselkin IV Babenkova TIu Bashkueva TM Modestova LS Steklova IuA Vladimirov 《Canadian Metallurgical Quarterly》1997,123(4):395-398
We examined whether X radiation induces a particular deletion in the mitochondrial DNA (mtDNA) of the cells of two human squamous cell carcinoma lines with different sensitivity to radiation and in a radiosensitive ataxia telangiectasia (AT) cell line. We used polymerase chain reaction (PCR) to quantify the accumulation of a particular 4977-bp deletion (delta mtDNA4977). PCR products of delta mtDNA4977 were detectable after exposure to 10 Gy in the radioresistant squamous cell carcinoma cells, 2 Gy in the radiosensitive squamous cell carcinoma cells and 1 Gy in the radiosensitive AT cells. These observations suggest that ionizing radiation induces the delta mtDNA4977 in human cells and that the radiation doses required to induce this deletion reflect the sensitivity of cells to radiation. 相似文献