2-quinolyl- and 1-isoquinolylnitrenes: Ring expansion and ring opening in heteroarylnitrenes

Argon matrix photolysis of tetrazolo[1,5-a]quinoline 8 and tetrazolo[5,1-a]isoquinoline 7 causes nitrogen elimination and ring expansion to 1,3-diazabenzo[d]cyclohepta-1,2,4,6-tetraene 13. The photolysis of tetrazolo[5,1-a]isoquinoline 7 also causes ring opening to o-cyanophenylketenimine 22. Mechanisms of ring opening of heteroarylnitrenes are discussed.

Usefulness of quantitative echocardiographic techniques to predict recovery of regional and global left ventricular function after acute myocardial infarction

The left ventricular response to dobutamine may be quantified using tissue Doppler measurement of myocardial velocity or displacement or 3-dimensional echocardiography to measure ventricular volume and ejection fraction. This study sought to explore the accuracy of these methods for predicting segmental and global responses to therapy. Standard dobutamine and 3-dimensional echocardiography were performed in 92 consecutive patients with abnormal left ventricular function at rest. Recovery of function was defined by comparison with follow-up echocardiography at rest 5 months later. Segments that showed improved regional function at follow-up showed a higher increment in peak tissue Doppler velocity with dobutamine therapy than in nonviable segments (1.2 +/- 0.4 vs 0.3 +/- 0.2 cm/s, p = 0.001). Similarly, patients who showed a > 5% improvement of ejection fraction at follow-up showed a greater displacement response to dobutamine (6.9 +/- 3.2 vs 2.1 +/- 2.3 mm, p = 0.001), as well as a higher rate of ejection fraction, response to dobutamine (9 +/- 3% vs 2 +/- 2%, p = 0.001). The optimal cutoff values for predicting subsequent recovery of function at rest were an increment of peak velocity > 1 cm/s, >5 mm of displacement, and a >5% improvement of ejection fraction with low-dose dobutamine. (C) 2003 by Excerpta Medica, Inc.

Evaluation of encapsulation techniques of probiotics for yoghurt

The health benefits provided by probiotic bacteria have led to their increasing use in fermented and other dairy products. However, their viability in these products is low. Encapsulation has been investigated to protect the bacteria in the product's environment and improve their survival. There are two common encapsulation techniques, namely extrusion and emulsion, to encapsulate the probiotics for their use in the fermented and other dairy products. This review evaluates the merits and limitations of these two techniques, and also discusses the supporting materials and special treatments used in encapsulation processes. (C) 2003 Elsevier Science Ltd. All rights reserved.

A role for pectin in the control of cell expansion

Uptake of nutrients and water depends on the growth of roots through elongation of individual cells near the. root tip. Many of the numerous components of Type I primary cell walls, those of dicotyledons and monocotyledons other than grasses (Poaceae), have been determined, and many hypotheses have been proposed for the control of cell expansion. This important aspect of plant growth still needs elucidation, however. A model is proposed in which pectin, which occurs as a calcium (Ca) pectate gel between the load-bearing cellulose microfibrils and xyloglucan (XG) chains, controls the rate at which cells expand. It is considered that the increasing tension generated by the expanding cell is transmitted to interlocked XG chains and cellulose microfibrils. The resulting deformation of the embedded Ca pectate gel elicits the excretion of protons from the cytoplasm, possibly via compounds such as cell wall-associated kinases, that weakens the Ca pectate gel, permitting slippage of XG molecules through the action of expansin. Further slippage is prevented by deformation of the pectic gel, proton diffusion, and the transfer of residual tension to adjacent XG chains. Evidence for this model is based on the effects of pH, Ca, and aluminum (Al) on root elongation and on the reactions of these cations with Ca pectate. This model allows for genetic selection of plants and adaptation of individual plants to root environmental conditions.

Modelagem da distribuição geográfica atual e futura de Guerlinguetus (Rodentia, Sciuridae) no Brasil

O gênero Guerlinguetus, pertencente à família Sciuridae, possui sete espécies existentes no Brasil. Essas espécies têm sido tratadas como sinônimos de Sciurus aestuans, mas foram distinguidas em um gênero próprio com base nas revisões taxonômicas mais abrangentes disponíveis até recentemente. Apesar disso, pouco há na literatura sobre a distribuição das espécies desse gênero no Brasil e nenhuma pesquisa visando o conhecimento de sua distribuição futura havia sido realizada. A modelagem de distribuição potencial de espécies tem se tornado um componente importante dos planos de conservação e uma grande quantidade de técnicas têm sido desenvolvidas com esta finalidade. Ela pode ser uma ferramenta importante para determinar o grau de ameaça principalmente em espécies ou grupos com poucas informações disponíveis sobre sua distribuição. Com isso, o objetivo do presente trabalho foi verificar a influência das possíveis mudanças climáticas na distribuição das espécies de Guerlinguetus no Brasil, através da modelagem potencial das distribuições atual e futura dessas espécies. Para isso foram utilizados dados climáticos e topográficos e o cenário pessimista de emissão de CO2 (A2) para o ano 2070, do Modelo de Circulação Geral CSIRO, com base no quarto relatório do Painel Intergovernamental de Mudanças Climáticas. Os modelos gerados apresentaram perda significativa de áreas consideradas ambientalmente adequadas, do modelo de distribuição atual para o modelo de distribuição futura para as espécies de Guerlinguetus, com exceção de G. aestuans. Apesar da expansão da região potencial de distribuição de G. aestuans para o ano de 2070, a média dos valores de adequabilidade ambiental diminuiu em relação ao modelo de distribuição atual. A localização dessas espécies de hábito arborícola em áreas geograficamente espalhadas dentro da Amazônia, Cerrado e Mata Atlântica é preocupante, devido a grande perda de área original desses biomas, tornando possível a hipótese de ameaça à sobrevivência das espécies devido a mudanças ambientais futuras.

Using different satellite imagery and classification techniques to assess the contribution of trees outside forests in the municipality of Maringá, Brazil

Forest cover of the Maringá municipality, located in northern Parana State, was mapped in this study. Mapping was carried out by using high-resolution HRC sensor imagery and medium resolution CCD sensor imagery from the CBERS satellite. Images were georeferenced and forest vegetation patches (TOFs - trees outside forests) were classified using two methods of digital classification: reflectance-based or the digital number of each pixel, and object-oriented. The areas of each polygon were calculated, which allowed each polygon to be segregated into size classes. Thematic maps were built from the resulting polygon size classes and summary statistics generated from each size class for each area. It was found that most forest fragments in Maringá were smaller than 500 m². There was also a difference of 58.44% in the amount of vegetation between the high-resolution imagery and medium resolution imagery due to the distinct spatial resolution of the sensors. It was concluded that high-resolution geotechnology is essential to provide reliable information on urban greens and forest cover under highly human-perturbed landscapes.

Accuracy Comparison of Implant Impression Techniques: A Systematic Review

Background: Several studies link the seamless fit of implant-supported prosthesis with the accuracy of the dental impression technique obtained during acquisition. In addition, factors such as implant angulation and coping shape contribute to implant misfit. Purpose: The aim of this study was to identify the most accurate impression technique and factors affecting the impression accuracy. Material and Methods: A systematic review of peer-reviewed literature was conducted analyzing articles published between 2009 and 2013. The following search terms were used: implant impression, impression accuracy, and implant misfit.A total of 417 articles were identified; 32 were selected for review. Results: All 32 selected studies refer to in vitro studies. Fourteen articles compare open and closed impression technique, 8 advocate the open technique, and 6 report similar results. Other 14 articles evaluate splinted and non-splinted techniques; all advocating the splinted technique. Polyether material usage was reported in nine; six studies tested vinyl polysiloxane and one study used irreversible hydrocolloid. Eight studies evaluated different copings designs. Intraoral optical devices were compared in four studies. Conclusions: The most accurate results were achieved with two configurations: (1) the optical intraoral system with powder and (2) the open technique with splinted squared transfer copings, using polyether as impression material.

Evaluation of staining techniques on the results of micronucleus in exfoliated oral mucosa cells

Micronuclei (MN) in exfoliated epithelial cells are widely used as biomarkers of cancer risk in humans. MN are classified as biomarkers of the break age and loss of chromosomes. They are small, extra nuclear bodies that arise in dividing cells from centric chromosome/chromatid fragments or whole chromosomes/chromatids that lag behind in anaphase and are not included in the daughter nuclei in telophase. Buccal mucosa cells have been used in biomonitoring exposed populations because these cells are in the direct route of exposure to ingested pollutant, are capable of metabolizing proximate carcinogens to reactive chemicals, and are easily and rapidly collected by brushing the buccal mucosa. The objective of the present study was to further investigate if, and to what extent, different stains have an effect on the results of micronuclei studies in exfoliated cells. These techniques are: Papanicolaou (PAP), Modified Papanicolaou, May-Grünwald Giemsa (MGG), Giemsa, Harris’s Hematoxylin, Feulgen with Fast Green counterstain and Feulgen without counterstain.

Identification of tsunami-induced deposits using numerical modeling and rock magnetism techniques: A study case of the 1755 Lisbon tsunami in Algarve, Portugal

Storm- and tsunami-deposits are generated by similar depositional mechanisms making their discrimination hard to establish using classic sedimentologic methods. Here we propose an original approach to identify tsunami-induced deposits by combining numerical simulation and rock magnetism. To test our method, we investigate the tsunami deposit of the Boca do Rio estuary generated by the 1755 earthquake in Lisbon which is well described in the literature. We first test the 1755 tsunami scenario using a numerical inundation model to provide physical parameters for the tsunami wave. Then we use concentration (MS. SIRM) and grain size (chi(ARM), ARM, B1/2, ARM/SIRM) sensitive magnetic proxies coupled with SEM microscopy to unravel the magnetic mineralogy of the tsunami-induced deposit and its associated depositional mechanisms. In order to study the connection between the tsunami deposit and the different sedimentologic units present in the estuary, magnetic data were processed by multivariate statistical analyses. Our numerical simulation show a large inundation of the estuary with flow depths varying from 0.5 to 6 m and run up of similar to 7 m. Magnetic data show a dominance of paramagnetic minerals (quartz) mixed with lesser amount of ferromagnetic minerals, namely titanomagnetite and titanohematite both of a detrital origin and reworked from the underlying units. Multivariate statistical analyses indicate a better connection between the tsunami-induced deposit and a mixture of Units C and D. All these results point to a scenario where the energy released by the tsunami wave was strong enough to overtop and erode important amount of sand from the littoral dune and mixed it with reworked materials from underlying layers at least 1 m in depth. The method tested here represents an original and promising tool to identify tsunami-induced deposits in similar embayed beach environments.