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An iron-sulfur compound (Fe3S2) was synthesized at pressures greater than 14 gigapascals in the system Fe-FeS. The formation of Fe3S2 changed the melting relations from a simple binary eutectic system to a binary system with an intermediate compound that melted incongruently. The eutectic temperature in the system at 14 gigapascals was about 400°C lower than that extrapolated from Usselman's data, implying that previous thermal models of Fe-rich planetary cores could overestimate core temperature. If it is found in a meteorite, the Fe3S2 phase could also be used to infer the minimum size of a parent body. 相似文献
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Tritrichomonas mobilensis is an intestinal parasite of squirrel monkeys. There are few reports concerning the morphological aspects of this parasite. In addition, the taxonomic relationship between T. mobilensis and Tritrichomonas foetus, a serious pathogen that causes bovine and feline trichomonosis, has been questioned. For this reason, in the present study, we examined and compared both tritrichomonads with regard to their morphology, ultrastructure, endocytic activity and cytotoxicity when in the presence of host cells. Electron microscopy demonstrated consistent morphological differences between the hydrogenosomes of both parasites. Moreover, T. mobilensis and T. foetus had striking differences in their endocytic behavior. Thus, this work provides additional data that support the hypothesis that T. mobilensis is a distinct species from T. foetus. 相似文献
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Use of Ozonization for the Treatment of Dye Wastewaters Containing Rhodamine B in the Agate Industry
Machado Ênio Leandro de Sales Dambros Vagner Kist Lourdes Teresinha Alcayaga Lobo Eduardo Alexis Tedesco Solange Bosio Moro Celso Camilo 《Water, air, and soil pollution》2012,223(4):1753-1764
The industrial processing of precious stones is a source of revenue for several Brazilian towns, especially in the state of
Rio Grande do Sul. Given the growing number of small-sized companies that process precious stones, wastewater production is
inevitable and is a cause for concern inasmuch as preservation of nature is considered. The present study investigates the
detoxification of the wastewater produced by the process of rhodamine B dyeing using oxidation processes. Ozonization (O3), ultraviolet irradiation (UV), and O3/UV methods were assessed. Some of the parameters used to measure the efficiency of the analyzed treatments included COD,
ecotoxicity (Daphnia magna), cytotoxicity, and genotoxicity assays (Allium cepa assays). Results show predominance of negative and local environmental impacts, which are reversible in more than 70% of
cases. The major proposed reversibility measures were the change in the process layout and dye wastewater segregation. Among
the analyzed methods, ozonization proved to be more efficient in decolorization, with 60 min of treatment, pH = 9 and dosage
of 5.705 mg O3/mg of rhodamine B. A pseudo first-order reaction, with a kinetic constant of 7.5 × 10−2 min−1, was observed. The cytotoxic and genotoxic effects were assessed for both raw and treated wastewaters. Despite complete decolorization,
cytotoxicity and genotoxicity assays revealed an EC50 of 28.6, in addition to chromosome aberrations in 40% of dividing cells for the treated wastewater. 相似文献
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Recent syntheses of high-pressure alkali and alkaline earth silicates reveal a class of framework structures with corner-linked 4- and 6-coordinated silicon. These compounds possess the structural formula (A4-2x1+Bx2+)SimVI(SinIVO2(m+n)+2), where x, m, and n specify the amounts of alkaline earth, 6-coordinated silicon, and 4-coordinated silicon, respectively. Appropriate values of m and n yield a range of high-pressure structures, from fully 4-coordinated to fully 6-coordinated silicate frameworks. Recognition of this class of framework silicates leads to predictions of high-pressure structures as well as room-pressure isomorphs of high-pressure silicates. 相似文献
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Volmir Kist Juliana Bernardi Ogliari José Branco de Miranda Filho Antonio Carlos Alves 《Euphytica》2010,176(1):25-36
Maize (Zea mays L.) is a very important cereal to world-wide economy which is also true for Brazil, particularly in the South region. Grain
yield and plant height have been chosen as important criteria by breeders and farmers from Santa Catarina State (SC), Brazil.
The objective of this work was to estimate genetic-statistic parameters associated with genetic gain for grain yield and plant
height, in the first cycle of convergent–divergent half-sib selection in a maize population (MPA1) cultivated by farmers within
the municipality of Anchieta (SC). Three experiments were carried out in different small farms at Anchieta using low external
agronomic inputs; each experiment represented independent samples of half-sib families, which were evaluated in randomized
complete blocks with three replications per location. Significant differences among half-sib families were observed for both
variables in all experiments. The expected responses to truncated selection of the 25% better families in each experiment
were 5.1, 5.8 and 5.2% for reducing plant height and 3.9, 5.7 and 5.0% for increasing grain yield, respectively. The magnitudes
of genetic-statistic parameters estimated evidenced that the composite population MPA1 exhibits enough genetic variability
to be used in cyclical process of recurrent selection. There were evidences that the genetic structure of the base population
MPA1, as indicated by its genetic variability, may lead to expressive changes in the traits under selection, even under low
selection pressure. 相似文献
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Two groups of 4 Hereford steers were housed in a controlled environment room and exposed to simulated high summer temperatures. Both groups were fed a barley grain and hay diet ad libitum. The barley in one diet contained 0.5% w/w ergots of Claviceps purpurea. Within one week of feeding the ergot diet mean rectal temperature was significantly elevated (P less than 0.05) each afternoon (up to 41 degrees C) but returned to normal overnight. Elevated rectal temperature was accompanied by other signs of heat stress, reduced feed intake, body weight loss and depression or serum prolactin concentration. Symptoms disappeared within 1 week of ceasing to feed the ergot diet. 相似文献
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