920 resultados para Conceptual functional density theory
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Julocrotine, N-(2,6-dioxo-l-phenethyl-piperidin-3-yl)-2-methyl-butyramide, is a potent antiproliferative agent against the promastigote and amastigote forms of Leishmania amazonensis (L.). In this work, the crystal structure of Julocrotine was solved by X-ray diffraction, and its geometrical parameters were compared with theoretical calculations at the B3LYP and HF level of theory. IR and NMR spectra also have been obtained and compared with theoretical calculations. IR absorptions calculated with the B3LYP level of theory employed together with the 6-311G+(d,p) basis set, are close to those observed experimentally. Theoretical NMR calculations show little deviation from experimental results. The results show that the theory is in accordance with the experimental data. (C) 2007 Wiley Periodicals, Inc.
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Quantum mechanical calculations at the B3LYP theory level, together with the 6-31G* basis set, were employed to obtain the energy, ionization potential, and polarizabilites for dipyridamole and derivatives, which are compared with their biological activity. Density functional calculations of the spin densities were performed for radical formed by electron abstraction of dipyridamole and derivatives. The unpaired electron remains in dipyridamole is localized on the nitrogen atoms in the substituent positions 1, 3, 5, 7, 11, 12, 13, 14, with participation of the 9 and 10 carbons in the pyrimido-pyrimidine ring. The antioxidant activity is related with ionization potential, polarizability and Log P.
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Triplet-excited riboflavin ((3)RF*) was found by laser flash photolysis to be quenched by polyunsaturated fatty acid methyl esters in tert-butanol/water (7:3, v/v) in a second-order reaction with k similar to 3.0 x 10(5) L mol(-1) s(-1) at 25 degrees C for methyl linoleate and 3.1 x 10(6) L mol(-1) s(-1), with Delta H double dagger = 22.6 kJ mol(-1) and Delta S double dagger = -62.3 J K(-1) mol(-1), for methyl linolenate in acetonitrile/water (8:2, v/v). For methyl oleate, k was <10(4) L mol(-1) s(-1). For comparison, beta-casein was found to have a rate constant k similar to 4.9 x 10(8) L mol(-1) s(-1). Singlet-excited flavin was not quenched by the esters as evidenced by insensitivity of steady-state fluorescence to their presence. Density functional theory (DFT) calculations showed that electron transfer from unsaturated fatty acid esters to triplet-excited flavins is endergonic, while a formal hydrogen atom transfer is exergonic (Delta G(HAT)degrees = -114.3, -151.2, and -151.2 kJ mol(-1) for oleate, linoleate, and linolenate, respectively, in acetonitrile). The reaction is driven by acidity of the lipid cation radical for which a pK(a) similar to -0.12 was estimated by DFT calculations. Absence of electrochemical activity in acetonitrile during cyclic voltammetry up to 2.0 V versus NHE confirmed that Delta G(ET)degrees > 0 for electron transfer. Interaction of methyl esters with (3)RF* is considered as initiation of the radical chain, which is subsequently propagated by combination reactions with residual oxygen. In this respect, carbon-centered and alkoxyl radicals were detected using the spin trapping technique in combination with electron paramagnetic resonance spectroscopy. Moreover, quenching of 3RF* yields, directly or indirectly, radical species which are capable of initiating oxidation in unsaturated fatty acid methyl esters. Still, deactivation of triplet-excited flavins by lipid derivatives was slower than by proteins (factor up to 10(4)), which react preferentially by electron transfer. Depending on the reaction environment in biological systems (including food), protein radicals are expected to interfere in the mechanism of light-induced lipid oxidation.
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This study describes the synthesis of novel biological hybrid materials, where 3D structures were obtained using gold nanoparticles (AuNps) and methionine (Met) in a one-step procedure in aqueous media. The type of nanostructure can be controlled by tuning the intermolecular interactions between Met and AuNp, which strongly depends on the pH used for the synthesis. Computational simulation using the density-functional theory (DFT) showed that the AuNp - Met 3D structures are formed upon reorientation of Met molecules so that the backbone amine groups interact via H-bonds. These findings were experimentally confirmed using FTIR and UV-vis spectroscopy. Crown Copyright (C) 2008 Published by Elsevier B. V. All rights reserved.
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For the past few decades, researchers have increased our understanding of how sound functions within various audio–visual media formats. With a different focus in mind, this study aims to identify the roles and functions of sound in relation to the game form Audio Games, in order to explore the potential of sound when acting as an autonomous narrative form. Because this is still a relatively unexplored research field, the main purpose of this study is to help establish a theoretical ground and stimulate further research within the field of audio games. By adopting an interdisciplinary approach to the topic, this research relies on theoretical studies, examinations of audio games and contact with the audio game community. In order to reveal the roles of sound, the gathered data is analyzed according to both a contextual and a functional perspective. The research shows that a distinction between the terms ‘function’ and ‘role’ is important when analyzing sound in digital games. The analysis therefore results in the identification of two analytical levels that help define the functions and roles of an entity within a social context, named the Functional and the Interfunctional levels. In addition to successfully identifying three main roles of sound within audio games—each describing the relationship between sound and the entities game system, player and virtual environment—many other issues are also addressed. Consequently, and in accordance with its purpose, this study provides a broad foundation for further research of sound in both audio games and video games.
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Consequences of role taking: the ”I”, the ”me” and individuality This paper analyzes the tendency of taking the ”I” and the ”me” in G. H. Meads theory of role taking as two separate, qualitatively different parts of human personality, the ”I” being of individual origin, the ”me” of social. In the original Meadian sense role taking gives rise to both the ”I” and the ”me”. They are dialectically united rather than dualistically separated aspects. They refer to the joint functional power of the subject, finding itself as an object, mediated by the Other. As a consequence, the link between body and the social world becomes theoretically more stringent, as the body is given its place as a cognitive social object among others, this by contrast to interpretations where the body is left as an object mainly outside the human social experience and as a source of agency sui generis, a conception which is in opposition to Meads. The stress on the ”I”-phase, as related to body and concrete action in combination with its direct relation to the ”me”-phase, actualizes Mead as a forerunner in modern biologic/neurologic research on human perceptual, motivational and intentional capacity.Swedish Mead interpreters are critically analyzed. Interpretations of Charon, Giddens, Joas and Habermas are partly scrutinized. The author defines the conceptual pair in terms of activity, subjectivity, temporal relativity and distance.
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Trata-se de uma pesquisa de natureza marcadamente descritiva, com etapas exploratórias, que visa a descrever as percepções e reflexões desveladas pelos sujeitos da pesquisa nas análises temáticas realizadas sobre diversas questões que envolvem o tema da autonomia da Perícia Criminal Oficial, no âmbito da Polícia Federal. Para esse fim, utilizou-se da metodologia da análise de conteúdo, segundo Bardin (1977). Os sujeitos da pesquisa foram escolhidos segundo o critério de acessibilidade e da natureza dos cargos, quais sejam: Delegado da Polícia Federal, Juiz Federal, Perito Criminal Federal e Procurador da República. Face à predominância do cunho qualitativo neste estudo, não há expectativas de generalizações dos resultados obtidos no campo, assim como a seleção desses sujeitos não priorizou pela representatividade quantitativa de cada cargo. O referencial teórico foi construído com o propósito de contextualizar e favorecer a compreensão do leitor sobre como é constituída a realidade em que se insere o objeto de estudo, buscando descrever os termos e conceitos necessários a essa compreensão, tais como: (i) o que é o Sistema de Justiça Criminal e como se deu seu processo de formação no Estado moderno; (ii) como é a estrutura e o fluxo processual básico do modelo brasileiro, com destaque para a posição que ocupam os órgãos ou Instituto de Criminalística; (iii) qual o nível de efetividade desse sistema, no Brasil, e quais os principais problemas que afetam a funcionalidade da Perícia Oficial em sua estrutura; (iv) quais os reflexos do uso dos paradigmas repressivo e preventivo, pelo Estado, no controle da violência, da criminalidade e da impunidade dos criminosos, visando a garantir a manutenção da ordem pública como bem coletivo; (v) que relevância tem o papel da Perícia Oficial para a efetividade do Sistema de Justiça Criminal, segundo o paradigma preventivo; (vi) o que é Criminalística e qual a natureza de sua atividade; e (vii) como se apresenta a atual estrutura administrativa e a rede de clientes da Perícia Oficial. Ao se aproximar do objeto de estudo, o pesquisador buscou descrever como se deu a origem do processo de autonomia da Criminalística, no Brasil, e como esse processo vem sendo desenhado como uma política de segurança pública, destacando as principais medidas administrativas e normativas adotadas no país que favoreceram a sua consolidação, tais como: a aprovação do PNSP (2002), do PNDH I (1996), do PNDH II (2002) e do PNDH III (2009), além da promulgação da Lei nº 12.030/2009, que assegura, de forma específica, a autonomia técnico-científica e funcional da função pericial criminal. Tratamento especial foi dado ao significado e ao alcance que têm as dimensões conceituais do termo “autonomia” para a função pericial. Em que pesem os resultados obtidos, as conclusões revelam que a complexidade do tema, teoria e prática, aguarda continuidade em pesquisas futuras.
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Physical Activity (PA) and functional fitness (FF) are predictors of a healthy and independent lifestyle in older adults. The purpose of this study was: (1) to construct reference values for FF; (2) to describe sex- and age-related changes in FF, balance, gait, PA, body composition, and bone health/strength; and (3) to determine their variation and co-variation with respect to PA. This cross-sectional study included 401 males and 401 females aged 60-79 years old. FF was assessed using the Senior Fitness test and balance by the Fullerton Advance Balance scale (FAB). Gait parameters: gait velocity (GV), stride length (SL), cadence and gait stability ratio (GSR) were measured. Femoral strength index (FSI) and bone mineral density (BMD) of the total body, lumbar spine, hip region and total lean tissue mass (TLTM) and total fat mass (TFM) were determined by dual-energy x-ray absorptiometry-DXA. PA was assessed during face-to-face interviews using the Baecke questionnaire. Demographic and health history information were obtained by structured telephone interview. In both sexes, a significant main effect for age-group was found for FF parameters, balance scores, gait performances, TLTM and hip, LS and total BMD and FSI. Likewise there were significant main effects for age-group for total PA in women and sports related PA in men. Men scored significantly better than women in FF (except in upper- and lower-body flexibility), balance, GV, SL, GSR and had higher BMD and TLTM compared with women. Active subjects scored better in FF, balance, and gait than their average and non-active peers. PA and FF exerted only a minor influence in the differentiation of BMD and FSI among the elderly while constitutive factors like age, height, body mass, TLTM and TFM entered as the most significant contributors. This study gives scientific support to public policies at the community level, targeted to increase PA, FF and TLTM, thereby contributing to improved quality of life in older adults.
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In this dissertation, the theoretical principles governing the molecular modeling were applied for electronic characterization of oligopeptide α3 and its variants (5Q, 7Q)-α3, as well as in the quantum description of the interaction of the aminoglycoside hygromycin B and the 30S subunit of bacterial ribosome. In the first study, the linear and neutral dipeptides which make up the mentioned oligopeptides were modeled and then optimized for a structure of lower potential energy and appropriate dihedral angles. In this case, three subsequent geometric optimization processes, based on classical Newtonian theory, the semi-empirical and density functional theory (DFT), explore the energy landscape of each dipeptide during the search of ideal minimum energy structures. Finally, great conformers were described about its electrostatic potential, ionization energy (amino acids), and frontier molecular orbitals and hopping term. From the hopping terms described in this study, it was possible in subsequent studies to characterize the charge transport propertie of these peptides models. It envisioned a new biosensor technology capable of diagnosing amyloid diseases, related to an accumulation of misshapen proteins, based on the conductivity displayed by proteins of the patient. In a second step of this dissertation, a study carried out by quantum molecular modeling of the interaction energy of an antibiotic ribosomal aminoglicosídico on your receiver. It is known that the hygromycin B (hygB) is an aminoglycoside antibiotic that affects ribosomal translocation by direct interaction with the small subunit of the bacterial ribosome (30S), specifically with nucleotides in helix 44 of the 16S ribosomal RNA (16S rRNA). Due to strong electrostatic character of this connection, it was proposed an energetic investigation of the binding mechanism of this complex using different values of dielectric constants (ε = 0, 4, 10, 20 and 40), which have been widely used to study the electrostatic properties of biomolecules. For this, increasing radii centered on the hygB centroid were measured from the 30S-hygB crystal structure (1HNZ.pdb), and only the individual interaction energy of each enclosed nucleotide was determined for quantum calculations using molecular fractionation with conjugate caps (MFCC) strategy. It was noticed that the dielectric constants underestimated the energies of individual interactions, allowing the convergence state is achieved quickly. But only for ε = 40, the total binding energy of drug-receptor interaction is stabilized at r = 18A, which provided an appropriate binding pocket because it encompassed the main residues that interact more strongly with the hygB - C1403, C1404, G1405, A1493, G1494, U1495, U1498 and C1496. Thus, the dielectric constant ≈ 40 is ideal for the treatment of systems with many electrical charges. By comparing the individual binding energies of 16S rRNA nucleotides with the experimental tests that determine the minimum inhibitory concentration (MIC) of hygB, it is believed that those residues with high binding values generated bacterial resistance to the drug when mutated. With the same reasoning, since those with low interaction energy do not influence effectively the affinity of the hygB in its binding site, there is no loss of effectiveness if they were replaced.
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Currently, computational methods have been increasingly used to aid in the characterization of molecular biological systems, especially when they relevant to human health. Ibuprofen is a nonsteroidal antiinflammatory or broadband use in the clinic. Once in the bloodstream, most of ibuprofen is linked to human serum albumin, the major protein of blood plasma, decreasing its bioavailability and requiring larger doses to produce its antiinflamatory action. This study aimes to characterize, through the interaction energy, how is the binding of ibuprofen to albumin and to establish what are the main amino acids and molecular interactions involved in the process. For this purpouse, it was conducted an in silico study, by using quantum mechanical calculations based on Density Functional Theory (DFT), with Generalized Gradient approximation (GGA) to describe the effects of exchange and correlation. The interaction energy of each amino acid belonging to the binding site to the ligand was calculated the using the method of molecular fragmentation with conjugated caps (MFCC). Besides energy, we calculated the distances, types of molecular interactions and atomic groups involved. The theoretical models used were satisfactory and show a more accurate description when the dielectric constant ε = 40 was used. The findings corroborate the literature in which the Sudlow site I (I-FA3) is the primary binding site and the site I-FA6 as secondary site. However, it differs in identifying the most important amino acids, which by interaction energy, in order of decreasing energy, are: Arg410, Lys414, Ser 489, Leu453 and Tyr411 to the I-Site FA3 and Leu481, Ser480, Lys351, Val482 and Arg209 to the site I-FA6. The quantification of interaction energy and description of the most important amino acids opens new avenues for studies aiming at manipulating the structure of ibuprofen, in order to decrease its interaction with albumin, and consequently increase its distribution
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The study investigated the possibility of organizing a didactics unit for formation of hability of identifying and explaining the popular traditional games in the process of licensed formation in physical education. Had basic premised, the thesis formulated by Piorte Yakovleviche Galperin that the fundamental condition that mode determines the student s way of thinking and the theoretical structures thought. Is given by the method of organization activity that form the basis of guiding skills assimilates from this assumption the study defended the thesis that the contents of popular traditional games can be organizeds according the systemic functional-structural focus. As a method to plan a didactics unit that contributes to development of theoretical thought and the professional development of graduates in physical education. In this sense the general goal was studied and develop a training proposal of ability to identify and explain the popular traditional games for physical education teachers oriented to contribute to the development of theoretical thought. In the construction process of the thesis in a first moment was determined the invariant conceptual of popular traditional games from the method of analysis of activity, after was organized the content of popular traditional games according to the structural-functional systems revealing the essential properties elements and levels of relationship.These procedures provided to the construction elements of the concept popular traditional games, and was the basis for planning a didactical unit to the formation of ability to study. These strategies enable to build a set of prepositions to argue, as a result of the increases in the knowledge of the professional formation in physical education. The study was introduced the fallowing contributions; formulated a teaching proposal to develop the ability to identify popular traditional games, as a cultural and historical contribution and the development of an individual, in initial formation of physical education teacher, attuned to the demands of training and use of knowledge that requires this level of education, defined and organized the knowledge of popular traditional games , this enables a teaching able to raise the cognitive abilities and the theoretical concept of personality of graduated in physical education
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The study investigated the possibility of organizing a didactics unit for formation of hability of identifying and explaining the popular traditional games in the process of licensed formation in physical education. Had basic premised, the thesis formulated by Piorte Yakovleviche Galperin that the fundamental condition that mode determines the student s way of thinking and the theoretical structures thought. Is given by the method of organization activity that form the basis of guiding skills assimilates from this assumption the study defended the thesis that the contents of popular traditional games can be organizeds according the systemic functional-structural focus. As a method to plan a didactics unit that contributes to development of theoretical thought and the professional development of graduates in physical education. In this sense the general goal was studied and develop a training proposal of ability to identify and explain the popular traditional games for physical education teachers oriented to contribute to the development of theoretical thought. In the construction process of the thesis in a first moment was determined the invariant conceptual of popular traditional games from the method of analysis of activity, after was organized the content of popular traditional games according to the structural-functional systems revealing the essential properties elements and levels of relationship.These procedures provided to the construction elements of the concept popular traditional games, and was the basis for planning a didactical unit to the formation of ability to study. These strategies enable to build a set of prepositions to argue, as a result of the increases in the knowledge of the professional formation in physical education. The study was introduced the fallowing contributions; formulated a teaching proposal to develop the ability to identify popular traditional games, as a cultural and historical contribution and the development of an individual, in initial formation of physical education teacher, attuned to the demands of training and use of knowledge that requires this level of education, defined and organized the knowledge of popular traditional games , this enables a teaching able to raise the cognitive abilities and the theoretical concept of personality of graduated in physical education
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Leaf-cutting ant workers dig underground chambers, for housing their symbiotic fungus, interconnected by a vast quantity of tunnels whose function is to permit the entrance of food (leaves), gaseous exchanges, andmovement of workers, offspring, and the queen. Digging is a task executed by a group of workers, but little is known about the group effect and group-constructed functional structures. Thus, we analyzed the structures formed by worker groups (5, 10, 20, and 40 individuals) of the leaf-cutting ant, Atta sexdens rubropilosa, for 2 days of excavation. The digging arena was the same for the 4 groups, with each group corresponding to a different density. Our results verified a pattern of tunneling by the workers, but no chamber was constructed. The group effect is well known, since the 40-worker group dug significantly more than the groups of 5, 10, and 20. These groups did not differ statistically from each other. Analysis of load/worker verified that workers of the smallest group carried the greatest load. Our paper demonstrates the group effect on the digging of nests, namely, that excavation is proportional to group size, but without emergence of a functional structure such as a chamber.
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Thin solid films of bis benzimidazo perylene (AzoPTCD) were fabricated using physical vapor deposition (PVD) technique. Thermal stability and integrity of the AzoPTCD PVD films during the fabrication (similar to 400 degrees C at 10(-6) Torr) were monitored by Raman scattering. Complementary thermogravimetric results showed that thermal degradation of AzoPTCD occurs at 675 degrees C. The growth of the PVD films was established through UV-vis absorption spectroscopy, and the surface morphology was surveyed by atomic force microscopy (AFM) as a function of the mass thickness. The AzoPTCD molecular organization in these PVD films was determined using the selection rules of infrared absorption spectroscopy (transmission and reflection-absorption modes). Despite the molecular packing, X-ray diffraction revealed that the PVD films are amorphous. Theoretical calculations (density functional theory, B3LYP) were used to assign the vibrational modes in the infrared and Raman spectra. Metallic nanostructures, able to sustain localized surface plasmons (LSP) were used to achieve surface-enhanced resonance Raman scattering (SERRS) and surface-enhanced fluorescence (SEF).