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61.
62.
Color center in amethyst quartz   总被引:1,自引:0,他引:1  
Treatment with x-rays increased the intensity of color of natural amethyst up to fivefold, and an electron paramagnetic resonance spectrum was detected. The intensity of the spectrum was proportional to the intensity of the optical absorption near 545 mmicro. The EPR spectrum of the color center corresponded to a positive hole trapped on a substitutional Fe(3+) ion in the quartz structure. We ascribe the color to a charge-transfer transition, Fe(4+) + O(2)- --> Fe(3+) + O(1-).  相似文献   
63.
Within the works for the registration of a new live Salmonella Enteritidis vaccine for layers, safety and efficacy of the vaccine strain were tested by experimental studies. After oral administration of the single and the tenfold dose, no incompatibility reactions were seen in day-old chicks. The laying performance and the egg weight were not affected by the vaccination of the chickens during the laying period. There was only a limited period in which the excretion of the vaccine strain and its persistency in organs were seen. Even after the threefold oral vaccination the vaccine strain could not be isolated from eggs and internal organs of slaughtered chickens. Moreover, a high safety for non-target animals (cattle, pigs) could be established. Studies with BALB/c mice proved that a cell-mediated immunity and the development of complement-fixing antibodies is induced by the vaccine. Efficacy studies in target animals were carried out by a proved dependable oral challenge system that reproduces a latent infection with marked S. Enteritidis strains and by means of the seeder-bird method. The test results demonstrate that the vaccination is capable to avert or to reduce an infection significantly.  相似文献   
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Zusammenfassung Zur gezielten Anwendung von Insektiziden gegen Borkenkäfer an Ziergehölzen sind Pyrethroid-Präparate zugelassen, die in Streichapplikation aufgebracht werden sollen. Mit Hilfe eines im Handel angebotenen Kleingerätes wurde vom Autor und von Garten- und Landschaftsbau- bzw. Baumschul-Unternehmen die Anwendung praktiziert und die gute Verwendbarkeit des technischen Hilfsmittels festgestellt. Auch die Anwendung eines zur Docht-Streichbehandlung zugelassenen Herbizides wurde erprobt. Ökonomische und ökologische Vorteile des Gerätes im Sinne der guten fachlichen Praxis werden aufgezeigt.  相似文献   
66.
Silicon-based quantum dots were intraperitoneally injected in individuals of Carassius auratus gibelio. Their effects on white muscle were investigated by following their distribution and impact on the antioxidative system. The GSH level significantly increased after 1 and 3?days of exposure by, respectively, 85.3 and 25.4%. Seven days later, GSH levels were similar to control concentrations. MDA concentration rose after three days by 46.9% and remained at the same level after 7?days. Protein thiol levels significantly decreased by 6.7 and 8.1% after 3 and 7?days, whereas advanced oxidation protein products increased by 12.7, respectively, 28.1% in the same time intervals. The protein reactive carbonyl groups were raised only after the first day of exposure and returned to the control level later on. SOD specific activity increased up to 48% after 7?days, while CAT activity increased by 328, 176, and 26% after 1, 3, and 7?days of treatment. GST specific activity was up-regulated by 87, 18, and 9%, while GR activity increased by 68, 34, and 9%. G6PD activity was up-regulated by 12, 22, and 50%, whereas GPx activity raised by 75 and 109% compared to control after, respectively, 1, 3, and 7?days. Our results suggest that oxidative stress induced by silicon-based quantum dots was not strong enough to cause permanent damage in the white muscle of crucian carp.  相似文献   
67.
This study evaluated the effects of dietary supplementation of organic acids blend (OAB) alone or in combination with essential oil, Lippia origanoides (OAE) for Nile tilapia fed supplemented diets for 30 days. Fish (1.1 ± 0.04 g) were fed control (Control), or OAB 0.5% or OAB 0.5% + essential oil 0.125% (OAE) respectively. At the end of the experiment, samples were collected for de hemato‐immunological, histological analysis of the intestine and liver, as well as microbiology of the intestine. The pH of the diets supplemented with OAB and OAE reduced 0.92 and 0.19 respectively. The growth and FCR were unaffected by the treatments, but survival was significantly higher in the OAB treatment. Fish fed the OAB diet showed reduced concentration of total heterotrophic bacteria and Pseudomonas sp. in the intestine. Increased glucose in fish fed OAB and high number of circulating monocytes in fish fed OAE diet were observed. The anterior intestine of fish fed OAE diet showed larger number of goblet cells and increased villi height. The diet supplemented with OAB, mainly, improved the intestinal health and survival of tilapia juveniles and can be used in juvenile production.  相似文献   
68.
Recent intensification efforts of astacid culture considerably depend on the appropriate assessment of the animal's physiological condition both for research and application. We conducted a 4 weeks feeding experiment to assess temporal resolution and accuracy of different response parameters (RNA/DNA ratio, RNA per wet weight, carapace length, wet weight, specific growth rate). Juvenile noble crayfish were exposed to five feeding regimes that differed in feeding frequency and food availability. Continuous growth was detected in all feeding regimes with individual increase up to 90% (wet weight) and 17% (carapace length), respectively. Morphometric parameters allowed separation of three weight‐groups or two length‐groups. During the experimental period RNA/DNA ratios showed both decrease (?17%) and increase (+35%), with superior accuracy than morphometric parameters, separating four groups. Based on RNA/DNA ratios, different feeding regimes were detected earlier, with two groups separated already after 3 weeks. RNA/DNA ratio was clearly superior to RNA per unit wet weight, as the latter failed to detect any differences between groups. In conclusion, RNA/DNA ratio is a valuable tool in nutritional studies with freshwater crayfish if overall growth is the key variable of interest.  相似文献   
69.
Book reviews     
Marilyn Holly is an Associate Professor of Philosophy at the University of Florida. Her special interests include political philosophy, ethics and ecology, Jungian thought, and Native American spirituality in its relation to the environment. She is currently at work on a monograph-length piece on the latter topic. She has taught an undergraduate course in ethics and ecology, and plans to do so again. The following essay emerged from her search for a suitable text for such a course.  相似文献   
70.
Swine Hepatitis E virus (HEV) can be transmitted from pigs to humans causing hepatitis. A high prevalence of HEV in wild boar populations is reported for several European countries, but actual data for Germany are missing. During the hunting season from October to December 2007 liver, bile and blood samples were collected from wild boars in four different German regions. The samples were tested for HEV RNA by quantitative PCR (qPCR) and anti-HEV IgG antibodies by two different ELISAs and a Line immunoassay. A seroprevalence of 29.9% using ELISA and 26.2% in the Line immunoassay was determined. The seroprevalence rate varied greatly within the analyzed regions. However, qPCR analysis revealed a higher prevalence of 68.2% positive animals with regional differences. Surprisingly, also adult wild sows and wild boars were highly HEV positive by qPCR. Compared to liver and serum samples, bile samples showed a higher rate of positive qPCR results. Sequencing and phylogenetic analysis of a 969 nt fragment within ORF 2 revealed that all isolates clustered within genotype 3 but differed in the subtype depending on the hunting spot. Isolates clustered within genotypes 3i, 3h, 3f and 3e. Within one population HEV isolates were closely related, but social groups of animals in close proximity might be infected with different subtypes. Two full-length genomes of subtypes 3i and 3e from two different geographic regions were generated. The wild boar is discussed as one of the main sources of human autochthonous infections in Germany.  相似文献   
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