Structural studies on the H3 influenza A virus haemagglutinin : Receptor binding and membrane fusion.

In this project, the receptor binding and membrane fusion activities of the membrane-anchored glycoprotein haemagglutinin (HA), H3 subtype, of the influenza A virus were studied. Influenza viruses from different hosts can distinguish between a.2-3 and a2-6 linkages that sialic acid (Sia) forms with the penultimate saccharide residue of the receptor. Human viruses prefer a2-6 linkages and avian viruses ct2-3 linkages. The side chain of residue 226 of the HA receptor binding site (RBS) is involved in the specific recognition of those linkages. The HA of the 1968 Hong Kong (HK) pandemic virus (H3 subtype), contained in the recombinant X-31 virus, has a 226-leucine and prefers binding to a2-6 linkages. The L226Q HA of the variant virus X-31/horse serum (X-31/HS), corresponding to a single-site mutant of the X-31 HA having 226-glutamine, prefers a2-3 linkages. To define the molecular interactions of the L226Q HA with the virus receptor, the crystal structures of L226Q HA in complex with the receptor analogues lactoseries tetrasaccharide a (LSTa), a2-3-terminated, and lactoseries tetrasaccharide c (LSTc), a2-6-terminated, were determined. The structures show the saccharide residues Sia and galactose (Gal) of LSTa and only the Sia of LSTc bound on the L226Q HA RBS, which correlates with the higher affinity of L226Q HA for the ct2-3 linkage. However, the L226Q HA binds both the trans and cis configurations of the Sia-Gal glycosidic bond of LSTa, which has never been observed before. These results are discussed in comparison with data from binding assays and the available crystal structures of the X-31 HA, the H3 avian HA of the influenza virus A/duck/Ukraine/63, a potential precursor of the 1968 HK pandemic virus, and other HAs, of different subtypes and hosts of origin, in complex with LSTa and LSTc. Upon endocytosis, at the low endosomal pH, the HA undergoes an irreversible conformational change associated with the fusion of the viral and endosomal membranes, a process by which the virus enters the target cell. To gain further insights into the membrane fusion mechanism catalysed by the influenza HA, the purification and crystallisation trials of three different X-31 HA forms representative of the neutral pH and fusion pH-induced conformations, containing the membrane-interacting segments fusion peptide and transmembrane anchor, were carried out with the future aim of their crystal structure determination. The procedures for the purification and crystallisation trials of the X-31 HA proteins in different conformations are discussed in the context of the general purification and crystallisation of membrane proteins. No promising hint has yet been obtained in the crystallisation trials

QUANTIFICATION OF THE COMPONENTS IN COMMERCIAL ESSENTIAL OIL OF EUCALYPTUS GLOBULUS LABILL. BY GAS CHROMATOGRAPHY – GC-FID AND GC-MS

Leaves of Eucalytus globulus Labill are characterized by the presence of essential oil, in which 1,8-cineole is the main component. The oil is used as an expectorant for symptomatic treatment of mild inflammation of the respiratory tract and bronchitis. This work addresses the chemical quantification of the constituents of E. globulus essential oil by gas chromatography. Commercial samples were diluted and analyzes by gas chromatograph coupled to flame ionization detector (GC-FID). The chromatographic separation was performed on a fused silica capillary (LM-20, 30 m x 0.25 mm x 0.25 μm film thickness) column. The proposed GC-FID method has demonstrated to have specificity and high sensitivity. The quantitation by the normalization technique demonstrated to be adequate for the analysis. Thus, the proposed method is effective for the quantification of E. globulus oil constituents, which may help in the quality control of commercial formulations.Leaves of Eucalytus globulus Labill are characterized by the presence of essential oil, in which 1,8-cineole is the main component. The oil is used as an expectorant for symptomatic treatment of mild inflammation of the respiratory tract and bronchitis. This work addresses the chemical quantification of the constituents of E. globulus essential oil by gas chromatography. Commercial samples were diluted and analyzes by gas chromatograph coupled to flame ionization detector (GC-FID). The chromatographic separation was performed on a fused silica capillary (LM-20, 30 m x 0.25 mm x 0.25 μm film thickness) column. The proposed GC-FID method has demonstrated to have specificity and high sensitivity. The quantitation by the normalization technique demonstrated to be adequate for the analysis. Thus, the proposed method is effective for the quantification of E. globulus oil constituents, which may help in the quality control of commercial formulations

The Thirring interaction in the two-dimensional axial-current-pseudoscalar derivative coupling model

The authors reexamine the two-dimensional model of massive fermions interacting with a massless pseudoscalar field via axial-current-pseudoscalar derivative coupling. Performing a canonical field transformation on the Bose field algebra the model is mapped into the Thirring model with an additional vector-current-scalar-derivative interaction (Schroer-Thirring model). The complete bosonized version of the model is presented. The bosonized composite operators of the quantum Hamiltonian are obtained as the leading operators in the Wilson short distance expansion.Comment: 13 page

Simulation models for tankless gas water heaters

There is a growing concern about to the scarceness of natural resources and the emissions problematic. Water heating is a relevant part of a household’s energy use, and tankless gas water heaters (TGWH) are widely used. There are design and engineering challenges to develop more efficient devices, with lower emissions of pollutant gases and providing comfort improvements from the user point of view. The main objective of the present work is to provide mathematical models to evaluate and support the development of different TGWH configurations. By simulation, different hardware configurations and advanced control strategies can be tested and optimized regarding energy saving, reducing of harmful environmental emissions and increase of comfort indices by reducing temperature undershoots and overshoots. The TGWH individual components are modelled, laboratory tests are performed and the heat cell is parametrized with experimental data. Configurations with and without bypass function are performed for several water flow rates and setpoint temperature patterns in open loop and with feed-forward control.publishe

Estudo comparativo das características sensoriais de carne de capão, galo, “frango do campo” e “frango comercial”.

A castração tem como objetivo promover o aumento do conteúdo em gordura intramuscular (Tor et al., 2002; Chen et al., 2005; Tor et al., 2005), melhorando o sabor, textura e suculência da carne (Chen et al., 2005; Tor et al., 2005). Tal efeito tem melhorado sensorialmente a qualidade da carne (Miguel et al., 2008; Webb e O'Neill, 2008), tornando-a mais apreciada pêlos consumidores do que a carne de galos da mesma idade (Chen et al., 2005; Tor et al., 2005). O presente trabalho teve como objetivo obter uma visão global e comparativa da carne de capões em relação aos galos, criados sob o mesmo sistema de produção.info:eu-repo/semantics/publishedVersio

Neonatal screening for cystic fibrosis in São Paulo State, Brazil : a pilot study

Cystic fibrosis is one of the most common autosomal recessive hereditary diseases in the Caucasian population, with an incidence of 1:2000 to 1:3500 liveborns. More than 1000 mutations have been described with the most common being F508del. It has a prevalence of 23-55% within the Brazilian population. The lack of population-based studies evaluating the incidence of cystic fibrosis in São Paulo State, Brazil, and an analysis concerning the costs of implantation of a screening program motivated the present study. A total of 60,000 dried blood samples from Guthrie cards obtained from April 2005 to January 2006 for neonatal screening at 4 reference centers in São Paulo State were analyzed. The immunoreactive trypsinogen (IRT)/IRT protocol was used with the cut-off value being 70 ng/mL. A total of 532 children (0.9%) showed IRT >70 ng/mL and a 2nd sample was collected from 418 (80.3%) of these patients. Four affected children were detected at two centers, corresponding to an incidence of 1:8403. The average age at diagnosis was 69 days, and 3 of the children already showed severe symptoms of the disease. The rate of false-positive results was 95.2% and the positive predictive value for the test was 8%. The cost of detecting an affected subject was approximately US$8,000.00 when this cystic fibrosis program was added to an existing neonatal screening program. The present study clearly shows the difficulties involved in cystic fibrosis screening using the IRT/IRT protocol, particularly in a population with no long-term tradition of neonatal screening421

Managing groundwater supplies subject to drought: perspectives on current status and future priorities from England (UK)

Effective management of groundwater resources during drought is essential. How is groundwater currently managed during droughts, and in the face of environmental change, what should be the future priorities? Four themes are explored, from the perspective of groundwater management in England (UK): (1) integration of drought definitions; (2) enhanced fundamental monitoring; (3) integrated modelling of groundwater in the water cycle; and (4) better information sharing. Whilst these themes are considered in the context of England, globally, they are relevant wherever groundwater is affected by drought

Kidney of Minke Whale (Baleanoptera acutorostrata): architecture and structure

Entre os mamíferos marinhos, a baleia é um dos animais que mais desperta atenção, especialmente no atinente ao seu sistema urinário. Este sistema segue o padrão entre os mamíferos quanto a sua constituição, entretanto, difere na morfologia renal, em número de lobos, que por sua vez, forma renículos completos, aglutinados às centenas. Esta estrutura é sustentada por tecido conjuntivo fibroso, mas altamente capaz de manter o equilíbrio hidroeletrolítico. Foram dissecados 6 pares de rins de baleia Minke (Balaenoptera acutorostrata), colhidos em 1982, Cabedelo, Estado da Paraíba, Brasil, na última pesca autorizada. Estes rins estavam conservados em formol 10% e apresentaram uma camada histológica de colágeno muito grande circundando a parede medular. O duto coletor urinário forma cálices papilares, desembocando num único centro coletor que desemboca no ureter. Verificou-se que o rim da baleia Minke apresenta característica lobulada possuindo em média 700 renículos, cada renículo possui características anatômicas e funcionais de um rim unipiramidal, com uma camada interna (medula), e uma camada externa (córtex), e irrigação independente, com formação das artérias arqueadas individualmente, como observadas em mamíferos terrestres unipiramidais. Entretanto, o conjunto destes renículos constitui ao final um rim multilobular e polipiramidal, contrariando a morfologia da maioria dos mamíferos terrestres. Não foi possível distinguir ao nível de microscopia de luz as estruturas do córtex renicular da baleia Minke. Na microscopia eletrônica de varredura foi possível visualizar uma camada cortical que fica localizada entre duas cápsulas fibrosas. Esta junção por sua vez é feita por tecido conjuntivo o qual juntamente com uma camada de colágeno e fibras elásticas, separa o córtex da medula , foram visualizados os glomérulos renais, completamente tomados pelos vasos glomerulares e dispostos em várias camadas. Percebe-se que a cavidade glomerular é praticamente um espaço virtual para onde o filtrado glomerular é drenado, não apresentando o formato globular. A vascularização intensifica-se ao chegar à região medular. A diferença entre rins de mamíferos terrestres e marinhos está na disposição dos componentes morfológicos, favorecendo a fisiologia do órgão