40 resultados para Kinetic Art
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
Giant extracellular hemoglobins are considered the summit of complexity in systems that carry oxygen, constituting an extraordinary model system to the study of hemoproteins. This class includes the hemoglobin of the annelid Glossoscolex paulistus that presents high cooperativity, great oligomeric and redox stabilities and ability of oligomeric reassociation. These properties have motivated evaluations about its utilization as prototype of artificial blood and biosensor. Kinetic studies involving autoxidation and detailed spectroscopic characterizations of its ferrous and ferric species have propitiated information about the structure-activity relationship of this macromolecule. The present review analyzes several biochemical issues, evaluating the state-of-art of this subject.
Resumo:
Lipase from Burkholderia cepacia immobilized on superparamagnetic nanoparticles using adsorption and chemisorption methodologies was efficiently applied as recyclable biocatalyst in the enzymatic kinetic resolution of (RS)-1-(phenyl)ethanols via transesterification reactions. (R)-Esters and the remaining (S)-alcohols were obtained with excellent enantiomeric excess (> 99%), which corresponds to a perfect process of enzymatic kinetic resolution (conversion 50%, E > 200). The transesterification reactions catalysed with B. cepacia lipase immobilized by the glutaraldehyde method showed the best results in terms of reusability, preserving the enzyme activity (conversion 50%, E > 200) for at least 8 successive cycles.
Resumo:
Polycyclic aromatic hydrocarbons (PAH) are widely distributed in the environment, and some are carcinogenic to human beings. The study of biomarkers has helped clarify the nature and magnitude of the human health risks posed by such substances. This article provides a review of the state-of-the-art on PAH biomarkers for human health risk assessment and also discusses their applicability within the context of environmental management in Brazil. The article discusses the methodologies for determination of some biomarkers such as 1-hydroxypyrene and PAH-DNA adducts. Cytogenetic markers, frequency of chromosomal aberrations, and micronucleus induction were considered for the evaluation of cancer risk. The current stage of studies on validation of such biomarkers was also approached.
Resumo:
Este artigo analisa as características assumidas pela arquitetura de tendência art déco em construções ligadas à indústria - moradias, igrejas, escolas, clubes, fábricas etc. - erguidas no Brasil nas décadas de 1930 e 1940, investigando o repertório formal utilizado em diferentes tipologias. Faz uma análise mais detalhada das construções criadas pela Companhia Industrial Fiação de Tecidos Goyanna, em Pernambuco, no período entre 1937 e o final da década de 1940. Trata-se de um conjunto notável pela unidade formal, vinculada à linguagem art déco, e pelo emprego de soluções inovadoras em termos de forma e de programa.
Resumo:
Purpose - The aim of this paper is to briefly present aspects of public brownfield management policies from Brazilian and German points of view. Design methodology approach - The data collection method combined literature and documental research. The bibliography included Brazilian and German literature about brownfield management. The documental research includes Brazilian and German legislation and official documents published by CETESB, the Environmental Company of the State of São Paulo, Brazil. Furthermore, publications of German governmental research institutions have been integrated in the paper. Findings - In Brazil, despite the lack of a federal public policy, the State of São Paulo has approved specific rules to deal with contaminated sites. Topics that could be targets of scientific studies have been identified. Experiences in Germany show that it is essential to have political will and cooperation between the different political levels and technical disciplines. Partnerships between German and Brazilian universities would be welcome as there is a wide range of opportunities for academic post-graduation studies and research focusing on human resources capacitation in environmental management. Originality value - The paper makes an original contribution of exploring an area (brownfield management) that is at the forefront of discussion in academe and industry
Resumo:
The topic of environmental sustainability is generating increased concern among business executives, governments, consumers, and management scholars. As these stakeholders struggle with the challenges and opportunities presented by an array of environmental issues, HRM scholars and practitioners alike have been relatively slow to engage in the ongoing discussions and debates. Through this special issue on Green FIRM, we seek to stimulate the field of HRM to expand its role in the pursuit of environmentally sustainable business. In this introduction to the special issue, we first provide an overview of the articles that appear in the special issue. Next we present a detailed discussion of research questions that arise from a consideration of several functional HRM practices, including performance management; training, development, and learning; compensation and rewards; and organizational culture. We conclude by describing opportunities for research at the intersection of strategic HRM and environmental management. If pursued with vigor, research addressing this extensive agenda could begin to establish a healthy field of Green FIRM scholarship.
Resumo:
Introduction: The purpose of this study was to compare the electromyography index of muscle coactivation of the following muscle pairs: posterior deltoid and pectoralis major (PD/PM); triceps brachii and biceps brachii (TB/BB); and serratus anterior and upper trapezius (SA/UT) during three different closed kinetic chain exercises (wall-press, bench-press and push-up) on an unstable surface at the maximal load. Methods: A total of 20 healthy sedentary men participated in the study. Integral linear values were obtained from three sustained contractions of six seconds each for the three proposed exercises. Mean coactivation index values were compared using the mixed-effects linear model, with a five percent significance level. Results: Electromyography indexes of muscle coactivation showed significant differences for the PD/PM and TB/BB muscle pairs. No differences were found between exercises for the SA/UT muscle pair. Conclusion: Our results seem to differ from those of previous studies, which reported that the similarity in exercises performed is responsible for the comparable muscle activation levels.
Resumo:
Purpose: To evaluate patellar kinematics of volunteers Without knee pain at rest and during isometric contraction in open- and closed-kinetic-chain exercises. Methods: Twenty individuals took part in this study. All were submitted to magnetic resonance imaging (MRI) during rest and voluntary isometric contraction (VIC) in the open anti closed kinetic chain at 15 degrees, 30 degrees, and 45 degrees of knee flexion. Through MRI and using medical e-film software, the following measurements were evaluated: sulcus angle, patellar-tilt angle, and bisect offset. The mixed-effects linear model was used for comparison between knee positions, between rest and isometric contractions, and between (he exercises. Results: Data analysis revealed that the sulcus angle decreased as knee flexion increased and revealed increases with isometric contractions in both the open and closed kinetic chain for all knee-flexion angles. The patellar-tilt angle decreased with isometric contractions in both the open and closed kinetic chain for every knee position. However, in the closed kinetic chain, patellar tilt increased significantly with the knee flexed at 15 degrees. The bisect offset increased with the knee flexed at 15 degrees during isometric contractions and decreased as knee flexion increased during both exercises. Conclusion: VIC in the last degrees of knee extension may compromise patellar dynamics. On the other hand, it is possible to favor patellar stability by performing muscle contractions with the knee flexed at 30 degrees and 45 degrees in either the open or closed kinetic chain.
Resumo:
The purpose of this study was to assess the benefits of using e-learning resources in a dental training course on Atraumatic Restorative Treatment (ART). This e-course was given in a DVD format, which presented the ART technique and philosophy. The participants were twenty-four dentists from the Brazilian public health system. Prior to receiving the DVD, the dentists answered a questionnaire regarding their personal data, previous knowledge about ART, and general interest in training courses. The dentists also participated in an assessment process consisting of a test applied before and after the course. A single researcher corrected the tests, and intraexaminer reproducibility was calculated (kappa=0.89). Paired t-tests were carried out to compare the means between the assessments, showing a significant improvement in the performance of the subjects on the test taken after the course (p<0.05). A linear regression model was used with the difference between the means as the outcome. A greater improvement on the test results was observed among female dentists (p=0.034), dentists working for a shorter period of time in the public health system (p=0.042), and dentists who used the ART technique only for urgent and/or temporary treatment (p=0.010). In conclusion, e-learning has the potential of improving the knowledge that dentists working in the public health system have about ART, especially those with less clinical experience and less knowledge about the subject.
Resumo:
Using a quasitoroidal set of coordinates with coaxial circular magnetic surfaces, Vlasov equation is solved for collisionless plasmas in drift approach and a perpendicular dielectric tensor is found for large aspect ratio tokamaks in a low frequency band. Taking into account plasma rotation and charge separation parallel electric field, it is found that an ion geodesic effect deform Alfveacuten wave continuum producing continuum minimum at the rational magnetic surfaces, which depends on the plasma rotation and poloidal mode numbers. In kinetic approach, the ion thermal motion defines the geodesic effect but the mode frequency also depends on electron temperature. A geodesic ion Alfveacuten mode predicted below the continuum minimum has a small Landau damping in plasmas with Maxwell distribution but the plasma rotation may drive instability.
Resumo:
Using a quasitoroidal set of coordinates with coaxial circular magnetic surfaces, the Vlasov equation is solved for collisionless plasmas, and the dielectric tensor is found for large aspect ratio tokamaks in a low frequency band. Taking into account q-profile and charge separation parallel electric field, it is found that the Alfven wave continuum is deformed by ion geodesic effects producing continuum minimum at the rational magnetic surfaces. Low frequency geodesic ion induced Alfven waves are found below the continuum minimum where collisionless damping has a gap for Maxwell distribution. In kinetic approach, the ion thermal motion defines the geodesic effect but the mode frequency is strongly corrected due to parallel motion of electrons.
Resumo:
Using a quasi-toroidal set of coordinates in plasmas with coaxial circular magnetic surfaces, the Vlasov equation is solved, and dielectric tensor is found for large aspect ratio tokamaks in a low frequency band. Taking into account the q-profile and drift effects, Alfven wave continuum deformation by geodesic effects is analyzed. It is shown that the Alfven continuum has a minimum defined by the ion thermal velocity at the rational magnetic surfaces q(s)=-M/N, where M and N are the poloidal and toroidal mode numbers, respectively, and the parallel wave number is zero. Low frequency global Alfven waves are found below the continuum minimum. In hot ion plasmas, the geodesic term changes sign, provoking some deformation of Alfven velocity by a factor (1+q(2))(-1/2), and the continuum minimum disappears. (C) 2008 American Institute of Physics.
Resumo:
We evaluate the coincidence spectra in the nonmesonic weak decay (NMWD) Lambda N -> nN of Lambda hypernuclei (4)(Lambda)He, (5)(Lambda)He, (12)(Lambda)C, (16)(Lambda)O, and (28)(Lambda)Si, as a function of the sum of kinetic energies E(nN)=E(n)+E(N) for N=n,p. The strangeness-changing transition potential is described by the one-meson-exchange model, with commonly used parametrization. Two versions of the independent-particle shell model (IPSM) are employed to account for the nuclear structure of the final residual nuclei. They are as follows: (a) IPSM-a, where no correlation, except for the Pauli principle, is taken into account and (b) IPSM-b, where the highly excited hole states are considered to be quasistationary and are described by Breit-Wigner distributions, whose widths are estimated from the experimental data. All np and nn spectra exhibit a series of peaks in the energy interval 110 MeV < E(nN)< 170 MeV, one for each occupied shell-model state. Within the IPSM-a, and because of the recoil effect, each peak covers an energy interval proportional to A(-1) , going from congruent to 4 MeV for (28)(Lambda)Si to congruent to 40 MeV for (4)(Lambda)He. Such a description could be pretty fair for the light (4)(Lambda)He and (5)(Lambda)He hypernuclei. For the remaining, heavier, hypernuclei it is very important, however, to consider as well the spreading in strength of the deep-hole states and bring into play the IPSM-b approach. Notwithstanding the nuclear model that is employed the results depend only very weakly on the details of the dynamics involved in the decay process proper. We propose that the IPSM is the appropriate lowest-order approximation for the theoretical calculations of the of kinetic energy sum spectra in the NMWD. It is in comparison to this picture that one should appraise the effects of the final-state interactions and of the two-nucleon-induced decay mode.
Resumo:
We develop a combined hydro-kinetic approach which incorporates a hydrodynamical expansion of the systems formed in A + A collisions and their dynamical decoupling described by escape probabilities. The method corresponds to a generalized relaxation time (tau(rel)) approximation for the Boltzmann equation applied to inhomogeneous expanding systems; at small tau(rel) it also allows one to catch the viscous effects in hadronic component-hadron-resonance gas. We demonstrate how the approximation of sudden freeze-out can be obtained within this dynamical picture of continuous emission and find that hypersurfaces, corresponding to a sharp freeze-out limit, are momentum dependent. The pion m(T) spectra are computed in the developed hydro-kinetic model, and compared with those obtained from ideal hydrodynamics with the Cooper-Frye isothermal prescription. Our results indicate that there does not exist a universal freeze-out temperature for pions with different momenta, and support an earlier decoupling of higher p(T) particles. By performing numerical simulations for various initial conditions and equations of state we identify several characteristic features of the bulk QCD matter evolution preferred in view of the current analysis of heavy ion collisions at RHIC energies.
Resumo:
The enzymatic kinetic resolution of tert-butyl 2-(1-hydroxyethyl) phenylcarbamate via lipase-catalyzed transesterification reaction was studied. We investigated several reaction conditions and the carbamate was resolved by Candida antarctica lipase B (CAL-B), leading to the optically pure (R)- and (S)-enantiomers. The enzymatic process showed excellent enantioselectivity (E > 200). (R)- and (S)-tert-butyl 2-(1-hydroxyethyl) phenylcarbamate were easily transformed into the corresponding (R)and (S)-1-(2-aminophenyl)ethanols.