Espectrometria Raman, UV, DOS e Circular Dicroísmo de alcalóides do cigarro

Esta dissertação aborda a análise espectroscópica de algumas estruturas moleculares presentes no tabaco (Nicotiana glauca), matéria-prima do cigarro, e suas interações com a molécula de DNA. De acordo com sua importância, dentre a grande variedade presentes no cigarro, às moléculas estudadas foram as derivadas do ácido nicotínico: ácido nicotínico (niacina/vitamina B3), nicotinamida, trigonelina, nicotina, nornicotina e anabasina. As otimizações dessas estruturas foram inicialmente obtidas no software computacional Hyperchem 8.0, baseadas na teoria da mecânica molecular. Em seguida, elas foram otimizadas, utilizando-se o método de Teoria do Funcional da Densidade, na base B3LYP/ 6-311++G(d,p), simulado no software Gaussian 03. Uma vez as estruturas otimizadas, obtivemos os espectros de absorção UV, Raman, Infravermelho, Dicroísmo Circular e Densidade de Estados para caracterizar as mesmas utilizando método de Teoria do Funcional da Densidade Dependente do Tempo, também simulados no mesmo software. Ao final desse processo, foi também simulado via mecânica molecular, as interações dessas estruturas com a molécula de DNA com o intuito de verificar a potencialidade cancerígena, ou não, dessas substâncias.

Scalar source in circular motion interacting with massive klein-gordon field in Minkowski spacetime

We analyze the scalar radiation emitted by a source in uniform circular motion in Minkowski spacetime interacting with a massive Klein-Gordon field. We assume the source rotating around a central object due to a Newtonian force. By considering the canonical quantization of this field, we use perturbation theory to compute the radiation emitted at the tree level. Regarding the initial state of the field as being the Minkowski vacuum, we compute the emission amplitude for the rotating source, assuming it as being minimally coupled to the massive Klein-Gordon field. We then compute the power emitted by the swirling source as a function of its angular velocity, as measured by asymptotic static observers.

Atividade antimicrobiana de uma resina acrílica para base protética combinada a um polímero antimicrobiano sobre a formação de biofilme

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação de enantiômeros em extratos vegetais por cromatografia quiral e dicroísmo circular

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dicroísmo circular vibracional e eletrônico na determinação da configuração absoluta de benzopiranos de Peperomia obtusifolia e Piper gaudichaudianum (Piperaceae): implicações biológicas e biossintéticas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morfologia e biometria do aparelho reprodutor feminino da capivara (Hydrochoerus hydrochaeris)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Categorias, níveis e causas de resistência de genótipos de feijoeiro a Zabrotes subfasciatus (Boheman, 1833) (Coleoptera: Bruchidae)

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Morphological characteristics of the Pterodoras granulosus digestive tube (Valenciennes, 1821) (Osteichthyes, Doradidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Analytical prediction of the spin stabilized satellite's attitude using the solar radiation torque

The aim of this paper is to present an analytical solution for the spin motion equations of spin-stabilized satellite considering only the influence of solar radiation torque. The theory uses a cylindrical satellite on a circular orbit and considers that the satellite is always illuminated. The average components of this torque were determined over an orbital period. These components are substituted in the spin motion equations in order to get an analytical solution for the right ascension and declination of the satellite spin axis. The time evolution for the pointing deviation of the spin axis was also analyzed. These solutions were numerically implemented and compared with real data of the Brazilian Satellite of Data Collection - SCD1 an SCD2. The results show that the theory has consistency and can be applied to predict the spin motion of spin-stabilized artificial satellites.

Spherical, cylindrical and tetrahedral symmetries; hydrogenic states at high magnetic field in Si:P

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inferring a weighted elastic network from partial unfolding with coarse-grained simulations

A number of studies have demonstrated that simple elastic network models can reproduce experimental B-factors, providing insights into the structure-function properties of proteins. Here, we report a study on how to improve an elastic network model and explore its performance by predicting the experimental B-factors. Elastic network models are built on the experimental C coordinates, and they only take the pairs of C atoms within a given cutoff distance r(c) into account. These models describe the interactions by elastic springs with the same force constant. We have developed a method based on numerical simulations with a simple coarse-grained force field, to attribute weights to these spring constants. This method considers the time that two C atoms remain connected in the network during partial unfolding, establishing a means of measuring the strength of each link. We examined two different coarse-grained force fields and explored the computation of these weights by unfolding the native structures. Proteins 2014; 82:119-129. (c) 2013 Wiley Periodicals, Inc.

In Vivo Osteogenesis and In Vitro Streptococcus mutans Adherence: Porous-Surfaced Cylindrical Implants vs Rough-Surfaced Threaded Implants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Impact of Quantity of Resin, C-factor, and Geometry on Resin Composite Polymerization Shrinkage Stress in Class V Restorations

Objective: This study evaluated the effect of quantity of resin composite, C-factor, and geometry in Class V restorations on shrinkage stress after bulk fill insertion of resin using two-dimensional finite element analysis.Methods: An image of a buccolingual longitudinal plane in the middle of an upper first premolar and supporting tissues was used for modeling 10 groups: cylindrical cavity, erosion, and abfraction lesions with the same C-factor (1.57), a second cylindrical cavity and abfraction lesion with the same quantity of resin (QR) as the erosion lesion, and then all repeated with a bevel on the occlusal cavosurface angle. The 10 groups were imported into Ansys 13.0 for two-dimensional finite element analysis. The mesh was built with 30,000 triangle and square elements of 0.1 mm in length for all the models. All materials were considered isotropic, homogeneous, elastic, and linear, and the resin composite shrinkage was simulated by thermal analogy. The maximum principal (MPS) and von Mises stresses (VMS) were analyzed for comparing the behavior of the groups.Results: Different values of angles for the cavosurface margin in enamel and dentin were obtained for all groups and the higher the angle, the lower the stress concentration. When the groups with the same C-factor and QR were compared, the erosion shape cavity showed the highest MPS and VMS values, and abfraction shape, the lowest. A cavosurface bevel decreased the stress values on the occlusal margin. The geometry factor overcame the effects of C-factor and QR in some situations.Conclusion: Within the limitations of the current methodology, it is possible to conclude that the combination of all variables studied influences the stress, but the geometry is the most important factor to be considered by the operator.