Detecção e erradicação de videiras com sintomas do cancro bacteriano no Estado do Paraná.

Suplemento. Edição dos Resumos do 44 Congresso Brasileiro de Fitopatologia, Bento Gonçalves, ago. 2011

Estudo cinético da dessorção térmica de diferentes álcoois e aldeído sobre H-Beta

Diferente da catálise homogênea ácida, a catálise heterogênea envolvendo sólidos ácidos tais como zeólitas se apresenta com alto grau de complexidade, devido a seletividade de forma e a distribuição heterogênea dos sítios ativos ao longo dasuperfície irregular no interior dos poros, conferindo assim uma reatividade única a estes materiais. Nesse contexto investigações sobre passos elementares de reação a fim de descrever um possível mecanismo reacional permitem gerar conhecimentos necessários para o projeto de reatores químicos, bem como o desenho e a síntese de novos catalisadores. Dessa forma para melhorar a concepção sobre o mecanismo do processo catalítico na esterificaçãosobre a superfície de zeólitas ácidas Gomes et al. [2], investigaram por espectroscopia de absorção no infravermelho e calcúlos de estruturas eletrônicas a adsorção de Ácido Acético e Metanol sobre H-Beta (H-β), os resultados encontrados indicaram que a interação do ácido carboxílico com o catalisador pode ocorre vía carbonila ou hidroxila, sendo mais favorável energeticamente a adsorção pelo grupo carbonila. Investigações aplicando análise termogravimétrica (TGA) mostram que a técnica de TGA pode ser usada para obtenção de dados cinéticos. Contudo, estudos sobre a cinética de degradação térmica, informam não apenas uma relação entre a taxa de aquecimento e a coordenada de reação, mas também fornecem estimativas sobre as curvas gravimétricas que podem ser relacionadas com a energia de ativação (Ea) e fatores pré-exponenciaisobtidos pelo método Flynn-Wall-Ozawa (FWO). Por tanto, a determinação do valor da Ea obtida sobre o processo de dessorção para moléculas de álcool ealdeído pode permitir descriminar a formação de um intermediário estável, resultante dos reagentes adsorvidos sobre a estrutura da zeólita BEA. Assimsendo a Ea obtida sobre esse sistema catalítico pode colaborar para a compressão da forma com que os ácidos carboxílicos se adsorvem para formar intermediários ativos na reação de esterificação. O objetivo deste trabalho está centrado na determinação da Ea de diferentes álcoois (Metanol, Etanol, Propanol e Butanol) e aldeído (Butanal), podendo estes resultados comprovar a hipótese descrita porGomes et al.fornecendo assim indícios sobre questões que envolvem o mecanismo de adsorção e catálise sobre H-β.Fil: Gomes, Glaucio José. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; ArgentinaFil: Benetti, Viviane. Universidade Federal do Paraná; BrasilFil: Zalazar, Maria Fernanda. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Arroyo, Pedro Augusto. Universidade Estadual de Maringá. Departamento de Engenharia Química.; BrasilFil: Scremin, Fernando R.. Universidade Federal do Paraná; BrasilFil: Bittencourt, Paulo R. S.. Universidade Federal do Paraná; BrasilXIII Encontro Regional de CatáliseSão CarlosBrasilUniversidad Federal de São Carlo

BOLD Temporal Dynamics of Rat Superior Colliculus and Lateral Geniculate Nucleus following Short Duration Visual Stimulation

Background: The superior colliculus (SC) and lateral geniculate nucleus (LGN) are important subcortical structures for vision. Much of our understanding of vision was obtained using invasive and small field of view (FOV) techniques. In this study, we use non-invasive, large FOV blood oxygenation level-dependent (BOLD) fMRI to measure the SC and LGN's response temporal dynamics following short duration (1 s) visual stimulation. Methodology/Principal Findings: Experiments are performed at 7 tesla on Sprague Dawley rats stimulated in one eye with flashing light. Gradient-echo and spin-echo sequences are used to provide complementary information. An anatomical image is acquired from one rat after injection of monocrystalline iron oxide nanoparticles (MION), a blood vessel contrast agent. BOLD responses are concentrated in the contralateral SC and LGN. The SC BOLD signal measured with gradient-echo rises to 50% of maximum amplitude (PEAK) 0.2±0.2 s before the LGN signal (p<0.05). The LGN signal returns to 50% of PEAK 1.4±1.2 s before the SC signal (p<0.05). These results indicate the SC signal rises faster than the LGN signal but settles slower. Spin-echo results support these findings. The post-MION image shows the SC and LGN lie beneath large blood vessels. This subcortical vasculature is similar to that in the cortex, which also lies beneath large vessels. The LGN lies closer to the large vessels than much of the SC. Conclusions/Significance: The differences in response timing between SC and LGN are very similar to those between deep and shallow cortical layers following electrical stimulation, which are related to depth-dependent blood vessel dilation rates. This combined with the similarities in vasculature between subcortex and cortex suggest the SC and LGN timing differences are also related to depth-dependent dilation rates. This study shows for the first time that BOLD responses in the rat SC and LGN following short duration visual stimulation are temporally different. © 2011 Lau et al

Two-Photon Imaging of Cortical Surface Microvessels Reveals a Robust Redistribution in Blood Flow after Vascular Occlusion

A highly interconnected network of arterioles overlies mammalian cortex to route blood to the cortical mantle. Here we test if this angioarchitecture can ensure that the supply of blood is redistributed after vascular occlusion. We use rodent parietal cortex as a model system and image the flow of red blood cells in individual microvessels. Changes in flow are quantified in response to photothrombotic occlusions to individual pial arterioles as well as to physical occlusions of the middle cerebral artery (MCA), the primary source of blood to this network. We observe that perfusion is rapidly reestablished at the first branch downstream from a photothrombotic occlusion through a reversal in flow in one vessel. More distal downstream arterioles also show reversals in flow. Further, occlusion of the MCA leads to reversals in flow through approximately half of the downstream but distant arterioles. Thus the cortical arteriolar network supports collateral flow that may mitigate the effects of vessel obstruction, as may occur secondary to neurovascular pathology

Recent research on Gulf War illness and other health problems in veterans of the 1991 Gulf War: Effects of toxicant exposures during deployment

Veterans of Operation Desert Storm/Desert Shield - the 1991 Gulf War (GW) - are a unique population who returned from theater with multiple health complaints and disorders. Studies in the U.S. and elsewhere have consistently concluded that approximately 25-32% of this population suffers from a disorder characterized by symptoms that vary somewhat among individuals and include fatigue, headaches, cognitive dysfunction, musculoskeletal pain, and respiratory, gastrointestinal and dermatologic complaints. Gulf War illness (GWI) is the term used to describe this disorder. In addition, brain cancer occurs at increased rates in subgroups of GW veterans, as do neuropsychological and brain imaging abnormalities. Chemical exposures have become the focus of etiologic GWI research because nervous system symptoms are prominent and many neurotoxicants were present in theater, including organophosphates (OPs), carbamates, and other pesticides; sarin/cyclosarin nerve agents, and pyridostigmine bromide (PB) medications used as prophylaxis against chemical warfare attacks. Psychiatric etiologies have been ruled out. This paper reviews the recent literature on the health of 1991 GW veterans, focusing particularly on the central nervous system and on effects of toxicant exposures. In addition, it emphasizes research published since 2008, following on an exhaustive review that was published in that year that summarizes the prior literature (RACGWI, 2008). We conclude that exposure to pesticides and/or to PB are causally associated with GWI and the neurological dysfunction in GW veterans. Exposure to sarin and cyclosarin and to oil well fire emissions are also associated with neurologically based health effects, though their contribution to development of the disorder known as GWI is less clear. Gene-environment interactions are likely to have contributed to development of GWI in deployed veterans. The health consequences of chemical exposures in the GW and other conflicts have been called "toxic wounds" by veterans. This type of injury requires further study and concentrated treatment research efforts that may also benefit other occupational groups with similar exposure-related illnesses