Entanglement Negativity and Concurrence in Some Low-Dimensional Spin Systems.

The influence of magnon bands on entanglement in the antiferromagnetic XXZ model on a triangular lattice, which models the bilayer structure consisting of an antiferromagnetic insulator and normal metal, is investigated. This effect was studied in ferromagnetic as well as antiferromagnetic triangular lattices. Quantum entanglement measures given by the entanglement negativity have been studied, where a magnon current is induced in the antiferromagnet due to interfacial exchange coupling between localized spins in the antiferromagnet and itinerant electrons in a normal metal. Moreover, quantum correlations in other frustrated models, namely the metal-insulation antiferromagnetic bilayer model and the Heisenberg model with biquadratic and bicubic interactions, are analyzed.

Non-Hermitian linear-response theory for spin diffusion in quantum systems.

Spin transport theory of non-Hermitian quantum systems, where the non-Hermiticity led to a series of exotic phenomena when the system experiences dissipation to an environment is proposed. The goal is a better understanding of the spin diffusion in the one-dimensional non-Hermitian XXZ model which allows the transport coefficients be computed analytically. Moreover, we analyzed the electric transport in the one-dimensional non-Hermitian Hubbard model which is a very important model of electrons strongly correlated, where we have investigated the effect of non-Hermitian parameters like the imaginary hopping on AC and DC conductivities of the system. We analyzed the large U limit of this model, where such non-Hermiticity contributes with a minus sign in the virtual exchange of quasiparticles and the behavior of the ground state energy and low-lying excitations is reversed.

Spin transport in non-Hermitian quantum systems.

Transport in non-Hermitian quantum systems is studied. The goal is a better understanding of transport in non-Hermitian systems like the Lieb lattice due to its flat bands and the integrability of the Ising chain which allows transport in that model to be computed analytically. This is a very special feature that is not present in a generic non-Hermitian system. We obtain the behaviour of the spin conductivity as a function of the non-Hermitian parameters of each system with aim to verify the influence of variation them on conductivity. For all models analyzed: Ising model as well as noninteracting fermion models, we obtain a little influence of the non-Hermitian parameters on conductivity and thus, a small effect over transport coefficients. Furthermore, we obtain an influence of opening of the gap in the spectrum in these models on longitudinal conductivity as well.

Dynamics based on analysis of public data for spreading of disease.

The stochastic model for epidemic spreading of the novel coronavirus disease based on the data set supply by the public health agencies in countries as Brazil, United States and India is investigated. We perform a numerical analysis using the stochastic differential equation in Itô's calculus for the estimating of novel cases daily, as well as analytical calculations solving the correspondent Fokker-Planck equation for the probability density distribution of novel cases, P(N(t), t). Our results display that the model based in the Itô's diffusion fits well to the results due to uncertainty in the official data and to the number of tests realized in populations of each country.

Efeito do treino com restrição de fluxo sanguíneo versus treino resistido de alta intensidade sobre a força de indivíduos sedentários: um ensaio clínico controlado e randomizado / Blood flow restriction training versus high-intensity resistance training in sedentary individuals: a randomized controlled trial

Objetivos: comparar os efeitos do treino com restrição de flux o sanguíneo com o treino resistido de alta intensidade no ganho de força e hipertrofia. Material e métodos: n este ensaio clínico randomizado e controlado, 24 homens sedentários foram randomizados em do is grupo s: treino com restrição de fluxo sanguíneo ou treino resistido de alta intensidade. Ambos os grupos realizaram 10 sessões de exercício de preensão manual até com 3 séries de exercícios até a falha, sendo que o grupo com treino de restrição de fluxo sanguíneo realizou com 30% da carga máxima obtida no teste de 1 repetição máxima, enquanto que o grupo de alta intensidade realizou com 80% da carga. T odo s o s voluntários foram avaliados e reavaliados a dinamometriade preensão manual e a perimetria de antebraço. Os dados foram tabulados e analisados no statistical package for the social sciences, utilizando o teste t-student, e o não paramétrico u de mann whitney, adotando a significância de 5% (α = 0,05). Resultados: para o desfecho força, identificou-se que tanto o grupo que treino com restrição do fluxo, quanto o grupo que treinou com alta intensidade tiveram aumentos significativos (p= 0,005 e 0,026, respectivamente). Já em relação ao aumento da circunferência, notou-se que somente o treino de restrição do flux o se mostrou estatisticamente quando comparado o aumento entre os grupos (p= 0,00 1). Conclusão: foi possível concluir que o treinamento com restrição do fluxo sanguíneo mostrou eficaz tanto para o ganho de força, quanto para o aumento de circunferência, apresentando vantagens quando comparado ao grupo de treinamento resistido com alta intensidade...(AU)

Objectives: to compare the effects of blood flow restriction trainin g wit h h igh in tensity resistance training on strength gain and hypertrophy. Material and methods: in this randomized controlled trial, 24 sedentary men were randomized into two groups: restricted blood flow training or high inten sity resistance training. Both groups performed 10 handgrip exercise sessions up to 3 sets of exercises un t il failure, and the group with blood flow restriction training performed with 3 0 % o f t he m ax imum lo ad obtained in the 1-repetition maximum test, while the high intensity group performed with 80% of the load. All volunteers were assessed and reassessed by handgrip dynamometry and forearm perimetry. Data were tabulated and analyzed in the statistical package for the social sciences, using the t-studen t test an d t he non-parametric mann whitney u test, adopting the significance of 5% (α = 0.05). Results: for the stren gth outcome, it was found that both the flow restriction training group and the high intensity train in g gro up had significant increases (p = 0.005 and 0.026, respectively). Regarding the increase in circumference, it was noted that only the flow restriction training was statistically when compared to the increase bet ween the groups (p = 0.001). Conclusion: it was concluded that training with blood flow restriction was effective for both strength gain and circumference increase, presenting advantages when compared to the high intensity resistance training group...(AU)

Profile and scientific production of CNPq researchers in Nephrology and Urology.

OBJECTIVE: This study aimed at evaluating the profile and scientific production of researchers in Nephrology and Urology, receiving grants in the area of Clinical Medicine from the Brazilian National Research Council. METHODS: The standardized online curriculum vitae (Curriculum Lattes) of 39 researchers in Medicine receiving grants in the 2006-2008 triennium were included in the analysis. The variables analyzed were: gender, affiliation, time from completion of the PhD program, scientific production, and supervision of undergraduate students, and master's and PhD programs. RESULTS: Males (74.4%) and category 2 grants (56.4%) predominated. The following three Brazilian states are responsible for 90% of the researchers: São Paulo (28; 71.8%); Rio Grande do Sul (4; 10.3%); and Minas Gerais (3; 7.7%). Four institutions are responsible for 70% of the researchers: UNIFESP (14; 36%); USP (8; 20.5%); UFMG (3, 7.7%); and UNICAMP (3; 7.7%). Considering the academic career, the assessed researchers published 3,195 articles in medical journals, with a median of 75 articles per researcher (QI = 52-100). The researchers received a total of 25,923 citations at the database Web of Science®, with a median of 452 citations per researcher (QI = 161-927). The average number of citations per article was 13.8 citations (SD = 11.6). CONCLUSIONS: The Southeastern region of Brazil concentrates researchers in Nephrology and Urology. Our study has shown an increase in the scientific production of most researchers in the last five years. By knowing the profile of researchers in Nephrology and Urology, more effective strategies to encourage the scientific production and the demand for resources to finance research projects can be defined.

Perfil e produção científica dos pesquisadores do CNPq nas áreas de nefrologia e urologia / Profile and scientific production of CNPq researchers in nephrology and urology

OBJETIVO: O objetivo deste estudo foi avaliar o perfil e a produção científica de pesquisadores de Nefrologia e Urologia, cadastrados como bolsistas de produtividade no Conselho Nacional de Desenvolvimento Científico e Tecnológico. MÉTODOS: Os currículos Lattes de 39 pesquisadores com bolsas ativas no triênio 2006 a 2008 foram incluídos na análise. As variáveis de interesse foram: sexo, instituição, tempo de doutoramento, artigos publicados, e orientação de alunos de graduação, mestres e doutores. RESULTADOS: Houve uma predominância do gênero masculino (74,4 por cento) e de bolsistas na categoria 2 (56,4 por cento). Três estados da federação são responsáveis por 90 por cento dos pesquisadores: SP (28; 71,8 por cento), RS (4; 10,3 por cento) e MG (3; 7,7 por cento). Quatro instituições são responsáveis por 70 por cento dos pesquisadores: UNIFESP (14; 36 por cento), USP (8; 20,5 por cento), UFMG (3, 7,7 por cento) e UNICAMP (3; 7,7 por cento). No total da carreira acadêmica, os pesquisadores em Nefrourologia publicaram 3.195 artigos em periódicos, sendo a mediana de 75 artigos por pesquisador (IQ = 52 - 100). Os pesquisadores receberam um total de 25.923 citações na base de dados Web of Science®, sendo a mediana por pesquisador de 452 citações (IQ = 161 - 927). A média de citações por artigo foi de 13,8 citações (DP = 11,6). CONCLUSÕES: Há uma concentração dos pesquisadores na região Sudeste. Neste estudo, pode ser observado um aumento da produção científica entre a maioria dos pesquisadores nos últimos cinco anos. Através do conhecimento do perfil dos pesquisadores das áreas de Nefrologia e Urologia podem ser definidas, de maneira mais eficaz, estratégias para incentivar a produção científica e a demanda de recursos para o financiamento de projetos de pesquisa.

OBJECTIVE: This study aimed at evaluating the profile and scientific production of researchers in Nephrology and Urology, receiving grants in the area of Clinical Medicine from the Brazilian National Research Council. METHODS: The standardized online curriculum vitae (Curriculum Lattes) of 39 researchers in Medicine receiving grants in the 2006-2008 triennium were included in the analysis. The variables analyzed were: gender, affiliation, time from completion of the PhD program, scientific production, and supervision of undergraduate students, and master's and PhD programs. RESULTS: Males (74.4 percent) and category 2 grants (56.4 percent) predominated. The following three Brazilian states are responsible for 90 percent of the researchers: São Paulo (28; 71.8 percent); Rio Grande do Sul (4; 10.3 percent); and Minas Gerais (3; 7.7 percent). Four institutions are responsible for 70 percent of the researchers: UNIFESP (14; 36 percent); USP (8; 20.5 percent); UFMG (3, 7.7 percent); and UNICAMP (3; 7.7 percent). Considering the academic career, the assessed researchers published 3,195 articles in medical journals, with a median of 75 articles per researcher (QI = 52-100). The researchers received a total of 25,923 citations at the database Web of Science®, with a median of 452 citations per researcher (QI = 161-927). The average number of citations per article was 13.8 citations (SD = 11.6). CONCLUSIONS: The Southeastern region of Brazil concentrates researchers in Nephrology and Urology. Our study has shown an increase in the scientific production of most researchers in the last five years. By knowing the profile of researchers in Nephrology and Urology, more effective strategies to encourage the scientific production and the demand for resources to finance research projects can be defined.