286 research outputs found
Electrochemical and positron annihilation studies of semicarbazones and thiosemicarbazones derived from ferrocene
A series of six ferrocene derivatives containing a semicarbazone or thiosemicarbazone side chain was investigated by cyclic voltammetry and positron annihilation lifetime measurements. Both the redox and the electron capture processes took place on the Fe atom. Correlations between the two methods were proposed, taking into account the substituents on the side chain of the compounds, their redox potentials and the probabilities of o-positronium (o-Ps).formation.Uma série de seis derivados de ferroceno contendo uma cadeia lateral de semicarbazona ou tiossemicarbazona foi investigada por voltametria cíclica e estudos utilizando medidas de tempo de vida de pósitrons. Ambos os fenômenos, tanto o processo redox como o de captura de elétrons, ocorreram no átomo de ferro. Foram propostas correlações entre os dois métodos, levando em conta os substituintes na cadeia lateral dos compostos, os potenciais redox e as probabilidades de formação de o-positrônio (o-Ps)
A COMPETITIVIDADE DO ARROZ GAÚCHO E SEUS CONDICIONANTES
This study aims to identify the main factors affecting rice supply in the state of Rio Grande do Sul and its competitiveness in Brazilian market. The Brazilian rice sector showed significant changes in the food chain after new agricultural policies, market liberalization and the Mercosul creation, which determined significant modifications in the allocation of production, in the quality of rice and in the productive structure of this sector.O presente estudo identifica os principais fatores que afetaram a produção de arroz no Estado do Rio Grande do Sul e a sua competitividade no mercado brasileiro. O setor arrozeiro brasileiro apresentou significativas mudanças na sua cadeia agroalimentar após o fim da política de incentivos e créditos subsidiados, a abertura comercial e a formação do Mercosul, que determinaram modificações substanciais na distribuição da produção no Brasil, na qualidade do produto e na estrutura produtiva do setor
A fração volátil das aguardentes de cana produzidas no Brasil
The volatile fraction of sugar cane spirits plays a key role in the quality and acceptance of these beverages. The composition of this fraction is dependent on the way sugar cane collection, fermentation, distillation and aging are carried out. The materials used in these processes strongly influence chemical composition. Acetic acid, acetaldehyde, ethyl acetate, ethanol, 2.3-butanedione, n-propanol, 3-methyl-buthanol and isobuthanol were the major volatiles in spirits. Dimethyl sulfide and n-propanol impaired beverage flavor. Ethyl octanoate, 1.1-diethoxy-ethane, 2-phenylethanol and 3-methyl-butanol were important aroma contributors. Ageing allows the extraction of flavor-active components (e.g., phenolic compounds) from wood
Perspectivas de pesquisas na relação entre clima e o funcionamento da Floresta Amazônica
Pesquisas recentes do programa LBA (Programa de\ud
Grande Escala da Biosfera‑Atmosfera na Amazônia)\ud
demonstram ligações entre o clima e o uso da terra\ud
na Amazônia e o funcionamento do bioma (1). A\ud
vegetação tem uma estreita relação com a atmosfera,\ud
controlando uma série de processos físico‑químicos que influenciam\ud
a taxa de formação de nuvens, quantidade de núcleos de condensação\ud
de nuvens, quantidade de vapor de água, balanço de radiação, emissão\ud
de gases biogênicos e de efeito estufa entre tantas outras propriedades.\ud
A Amazônia, por sua localização tropical e grande área (Figura 1), é\ud
uma importante fonte de vapor de água para nosso planeta. Ela também\ud
contém o maior reservatório de carbono entre os ecossistemas\ud
terrestres, e tem um papel fundamental na mitigação das mudanças\ud
climáticas em curso. A mobilização de pequena fração do carbono\ud
acumulado na biomassa da floresta pode perturbar o ciclo de carbono\ud
global. A Amazônia também é parte do mais intenso ciclo hidrológico\ud
de nosso planeta, com um sofisticado processamento e reciclagem de\ud
vapor de água, que alimenta a maior bacia hidrológica. Estes aspectos\ud
fazem da região amazônica uma questão central em pesquisas de clima\ud
e nas mudanças globais. Desde seu início, o programa LBA focou no\ud
relacionamento entre clima, ciclos biogeoquímicos e o papel da mudança\ud
de uso do solo em curso, alterando o funcionamento do bioma
Meeting Report: Development of Environmental Health Indicators in Brazil and Other Countries in the Americas
This report summarizes the Brazilian experience on the design and implementation of environmental health, with contributions from Argentina, Canada, and Cuba, presented at the International Symposium on the Development of Indicators for Environmental Health Integrated Management, held in Recife, Pernambuco, Brazil, on 17–18 June 2004. The methodology for the development of environmental health indicators has been used as a reference in the implementation of environmental health surveillance in Brazil. This methodology has provided tools and processes to facilitate the understanding and to measure the determinants of risks to environmental health, to help decision makers control those risks
Biological aspects of the leafminer Liriomyza sativae (Diptera: Agromyzidae) on melon (Cucumis melo L.)
Analysis of four dispersion vectors in inland waters: the case of the invading bivalves in South America
As a consequence of the current globalization of commerce, natural environments are subject to an unprecedented dynamic transport of organisms because global conditions favor transport, settlement, and dispersal of invading species. These produce widespread impacts such as decreased agricultural and utility production, increased health risks to humans and wildlife, and a significant decrease in native biodiversity. On the assumption that it is better to prevent bioinvasions than to control them, it is of paramount importance to identify and manage the potential dispersal vectors to implement preventive strategies. In our study, we identified 4 potential vectors in southern Brazil (sand transport, attachment to hulls of sports fishing boats, water in sports fishing boats, and live fish) for 2 freshwater invasive bivalves (Corbicula fluminea and Limnoperna fortunei). For each of these potential vectors, we assess the potential for dispersal by estimating the probability of finding larvae or adults, setting groundwork for further studies on the risks of invasion to which the region is subject.Facultad de Ciencias Naturales y MuseoConsejo Nacional de Investigaciones Científicas y Técnica
Oral Melanoacanthoma And Oral Melanotic Macule: A Report Of 8 Cases, Review Of The Literature, And Immunohistochemical Analysis
Oral melanoacanthoma (MA) is a rare, benign pigmented lesion, similar to cutaneous MA, characterized by hyperplasia of spinous keratinocytes and dendritic melanocytes. The pathogenesis of oral MA remains uncertain, although its clinical behavior is suggestive of a reactive origin. The most common intraoral sites are the buccal mucosa, lip, palate and gingiva. The average age of presentation is 28 years, mainly in blacks, with a strong female predilection. The oral melanotic macule (MM) is a small, well-circumscribed brown-to-black macule that occurs on the lips and mucous membranes. The etiology is not clear and it may represent a physiologic or reactive process. The average age of presentation is 43 years, with a female predilection. A biopsy is recommended to distinguish these lesions from each other and from other oral melanocytic lesions. We depict four cases each of oral MA and MM, affecting Caucasian and Latin American mestizo patients. The clinicopathological features of these cases reflect its ample spectrum, and to the best of our knowledge, it is the first example of oral MA affecting a Caucasian boy reported in the English literature. Therefore oral MA and MM should be considered in the differential diagnosis of pigmented lesions in the oral mucosa in these populations. © Medicina Oral.125E374E379Mishima, Y., Pinkus, H., Benign mixed tumor of melanocytes and malpighian cells. Melanoacanthoma: Its relationship to Bloch's benign non-nevoid melanoepithelioma (1960) Arch Dermatol, 81, pp. 539-550Buchner, A., Merrell, P.W., Carpenter, W.M., Relative frequency of solitary melanocytic lesions of the oral mucosa (2004) J Oral Pathol Med, 33, pp. 550-557Wright, J.M., Binnie, W.H., Byrd, D.L., Dunsworth, A.R., Intraoral melanoacanthomas (1983) J Periodontol, 54, pp. 107-111Buchner, A., Merrell, P., Hanson, L., Leider, A., Melanocytic hyperplasia of the oral mucosa (1991) Oral Surg, Oral Med Oral Pathol, 71, pp. 58-62Wright, J.M., Intraoral melanoacanthoma: A reactive melanocytic hyperplasia. Case report (1988) J Periodontol, 59, pp. 53-55Tomich, C., Zunt, S.L., Melanoacanthosis (melanoacanthoma) of the oral mucosa (1990) J Dermatol Surg Oncol, 16, pp. 231-236Contreras, E., Carlos, R., Oral melanoacanthosis (melanoachantoma): Report of a case and review of the literature (2005) Med Oral Patol Oral Cir Bucal, 10 (1), pp. 11-12,9-11Fornatora, M.L., Reich, R.F., Haber, S., Solomon, F., Freedman, P.D., Oral melanoacanthomas: A report of 10 cases, review of the literature, and immunohistochemical analysis for HMB-45 reactivity (2003) Am J Dermatopathol, 25, pp. 12-15Matsuoka, L.Y., Glasser, S., Barsky, S., Melanoacanthoma of the lip (1979) Arch Dermatol, 115, pp. 1116-1117Goode, R.K., Crawford, B.E., Callihan, M.D., Neville, B.W., Oral melanoacanthoma. Review of the literature and report of ten cases (1983) Oral Surg Oral Med Oral Pathol, 56, pp. 622-628Scheneider, L.C., Mesa, M.L., Haber, S.M., Melanoacanthoma of the oral mucosa (1981) Oral Surg Oral Med Oral Pathol, 52, pp. 284-287Fatahzadeh, M., Sirois, D.A., Multiple intraoral melanoacanthomas: A case report with unusual findings (2002) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 94, pp. 54-56Ho, K.K., Dervan, P., O'Loughlin, S., Powell, F.C., Labial melanotic macule: A clinical, histopathologic, and ultrastructural study (1993) J Am Acad of Dermatol, 28, pp. 33-39Sexton, F.M., Maize, J.C., Melanotic macules and melanoacanthomas of the lip. A comparative study with census of the basal melanocyte population (1987) Am J Dermatopathol, 9, pp. 438-444Horlick, H.P., Walther, R.R., Zegarelli, D.J., Silvers, D.N., Eliezri, Y.D., Mucosal melanotic macule, reactive type: A simulation of melanoma (1988) J Am Acad Dermatol, 19, pp. 786-791Buchner, A., Hansen, L.S., Pigmented nevi of the oral mucosa: A clinicopathologic study of 32 new cases and review of 75 cases from the literature: Part I. A clinicopathologic study of 32 new cases (1979) Oral Surg Oral Med Oral Pathol, 48, pp. 131-142Barker, B.F., Carpenter, W.M., Daniels, T.E., Kahn, M.A., Leider, A.S., Lozada-Nur, F., (1997) Oral mucosal melanomas: The WESTOP Banff workshop proceedings, 83, pp. 672-679. , Western Society of Teachers of Oral Pathology. Oral Surg Oral Med Oral Pathol Oral Radiol EndodBarrett, A.W., Raja, A.M., The immunohistochemical identification of human oral mucosal melanocytes (1997) Arch Oral Biol, 42, pp. 77-8
Caracterização do vírus da raiva isolado de uma colônia de morcegos Eptesicus furinalis, do Brasil
Some bat species have adapted to the expanding human population by acquiring the ability to roost in urban buildings, increasing the exposure risk for people and domestic animals, and consequently, the likelihood of transmitting rabies. Three dead bats were found in the yard of a house in an urban area of Jundiaí city in the state of São Paulo in southeast Brazil. Two of the three bats tested positive for rabies, using Fluorescent Antibody and Mouse Inoculation techniques. A large colony of Eptesicus furinalis was found in the house's attic, and of the 119 bats captured, four more tested positive for rabies. The objectives of this study were to report the rabies diagnosis, characterize the isolated virus antigenically and genetically, and study the epidemiology of the colony.Algumas espécies de morcegos têm se adaptado ao uso de abrigos em construções urbanas, aumentando a possibilidade de contato desses morcegos com pessoas e animais domésticos e conseqüentemente, o potencial risco de transmissão de raiva. Três morcegos foram encontrados no jardim de uma casa na área urbana da cidade de Jundiaí, Estado de São Paulo, Sudeste do Brasil, dois deles foram positivos para raiva pelas técnicas de imunofluorescência e inoculação em camundongos. Uma grande colônia de E. furinalis foi identificada, vivendo no sótão da casa e 119 morcegos foram encaminhados para diagnóstico de raiva, com mais quatro morcegos positivos. O objetivo desse estudo é apresentar a caracterização genética e antigênica do vírus da raiva isolado desses morcegos e o estudo epidemiológico da colônia
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