Emergence of Chern Supermetal and Pair-Density Wave through Higher-Order Van Hove Singularities in the Haldane-Hubbard Model

While advances in electronic band theory have brought to light new topological systems, understanding the interplay of band topology and electronic interactions remains a frontier question. In this work, we predict new interacting electronic orders emerging near higher-order Van Hove singularities present in the Chern bands of the Haldane model. We classify the nature of such singularities and employ unbiased renormalization group methods that unveil a complex landscape of electronic orders, which include ferromagnetism, density-waves and superconductivity. Importantly, we show that repulsive interactions can stabilize long-sought pair-density wave state and an exotic Chern supermetal, which is a new class of non-Fermi liquid with anomalous quantum Hall response. This framework opens a new path to explore unconventional electronic phases in two-dimensional chiral bands through the interplay of band topology and higher-order Van Hove singularities.Comment: 6 pages; 3 figure

Hole concentration in a diluted ferromagnetic semiconductor

We consider a mean-field approach to the hole-mediated ferromagnetism in III-V Mn-based semiconductor compounds to discuss the dependence of the hole density on that of Mn sites in Ga_{1-x}Mn_xAs. The hole concentration, p, as a function of the fraction of Mn sites, x, is parametrized in terms of the product m*J_{pd}^2 (where m* is the hole effective mass and J_{pd} is the Kondo-like hole/local-moment coupling), and the critical temperature Tc. By using experimental data for these quantities, we have established the dependence of the hole concentration with x, which can be associated with the occurrence of a reentrant metal-insulator transition taking place in the hole gas. We also calculate the dependence of the Mn magnetization with x, for different temperatures (T), and found that as T increases, the width of the composition-dependent magnetization decreases drammatically, and that the magnetization maxima also decreases, indicating the need for quality-control of Mn-doping composition in diluted magnetic semiconductor devices.Comment: 4 pages, 3 figures, RevTeX 3; Fig. 1 changed, new references adde

A combined approach for comparative exoproteome analysis of Corynebacterium pseudotuberculosis

Background: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and goats. Results: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome. Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of most of the remaining proteins. Conclusions: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far

Estudo clínico duplo cego comparando praziquantel com oxamniquine

Com objetivo de se compararem a tolerabilidade e eficácia do praziquantel e oxamniquine, procedeu-se a um estudo prospectivo duplo-cego envolvendo 120 pacientes com esquistossomose intestinal ou hepatintestinal. Os pacientes foram randomizados em dois grupos. Um foi tratado com praziquantel, na dose de 55 mg/kg de peso, o outro com oxamniquine, 15 mg/kg de peso, sempre administrados em dose única por via oral. O diagnóstico e seguimento parasitológicos basearam-se ho exame de fazes peio método de Kate Katz. Em 73 de 77 casos negativos após tratamento, executaram-se biópsias retais. Efeitos colaterais, principalmente tontura, sonolência, dores abdominais, cefaléia, náuseas e diarréia foram observados em 87% dos casos. Sua incidência, intensidade e duração foram semelhantes em ambos os grupos, mas a dor abdominal foi significativamente mais freqüente após praziquantel, havendo maior tendência para tontura intensa após oxamniquine. Observou-se aumento significante de alamina-aminotransferase e gama-glutamiltransferase após oxamniquine e de bilirrubina total após praziquantel. Um total de 48 pacientes tratados com praziquantel e 46 com oxamniquine completaram os exames de controle até o sexto mês. As percentages de cura foram de 79,2% e de 84,8% respectivamente, diferença não significativa. Os pacientes não curados mostraram redução média do número de ovos de 93,5% e de 84,1%, diferença não significativa. Cinco pacientes retratados com praziquantel curaram-se, mas somente um de três retratados com oxamniquine. Estes resultados mostram, que ambas as drogas-apesar de diferentes propriedades farmacológicas provocam reações colaterais semelhantes e apresentam eficácia terapêutica comparável.A double-blind clinical trial involving 120 patients with chronic schistosomiasis was carried out to compare the tolerability and efficacy of praziquantel and oxamniquine. The patients were randomly allocated into two groups. One was treated with praziquantel, 55 mg/kg of body weight CBWT), and the other one with oxamniquine, 15mg/kg bwt, administered in a single oral dose. The diagnosis and the parasitological follow-up was based on stool examinations by quantitative Kato-Katz method and on rectal biopsies. Side-effects mainly dizziness, sleepness, abdominal distress, headache, nausea and diarrhea were observed in 87% of the cases. Their incidence, intensity and duration were similar for both drugs but abdominal pain was significantly more frequent after praziquantel intake and severe dizziness was more commonly reported after oxamniquine. A significant increase of alanine-aminotransferase and y-glutamyltransferase was found with the latter drug and of total bilirubin with the former one. A total of 48 patients treated with praziquantel and 46 with oxamniquine completed with negative findings the required three post-treatment parasitological controls three slides of each stool sample on the first, third and sixth month. The achieved cure rates were 79.2% and 84.8%, respectively, a difference without statistical significance. The non-cured cases showed a mean reduction in the number of eggs per gram of feces of 93.5% after praziquantel and of 84.1% after oxamniquine. This diference also was not significant. Five patients retreated with praziquantel were cured but only one out of three treated a second time with oxamniquine. These findings show that both drugs despite their different chemical structures, pharmacological properties and mechanisms-of-action induce similar side-effects as well as a comparable therapeutical efficacy, in agreement with the results reported from analogous investigations

Genetic diversity of the E Protein of Dengue Type 3 Virus

<p>Abstract</p> <p>Background</p> <p>Dengue is the most important arbovirus disease in tropical and subtropical countries. The viral envelope (E) protein is responsible for cell receptor binding and is the main target of neutralizing antibodies. The aim of this study was to analyze the diversity of the E protein gene of DENV-3. E protein gene sequences of 20 new viruses isolated in Ribeirao Preto, Brazil, and 427 sequences retrieved from GenBank were aligned for diversity and phylogenetic analysis.</p> <p>Results</p> <p>Comparison of the E protein gene sequences revealed the presence of 47 variable sites distributed in the protein; most of those amino acids changes are located on the viral surface. The phylogenetic analysis showed the distribution of DENV-3 in four genotypes. Genotypes I, II and III revealed internal groups that we have called lineages and sub-lineages. All amino acids that characterize a group (genotype, lineage, or sub-lineage) are located in the 47 variable sites of the E protein.</p> <p>Conclusion</p> <p>Our results provide information about the most frequent amino acid changes and diversity of the E protein of DENV-3.</p

Prevalence of vitamin D deficiency, insufficiency and secondary hyperparathyroidism in the elderly inpatients and living in the community of the city of São Paulo, Brazil

The occurrence of osteoporotic fractures in the elderly is associated with reduced levels of vitamin D and resulting secondary hyperparathyroidism, and inpatients are the ones at a higher risk. In Brazil, given its high level of insolation, the population s large amount of vitamin D is inferred to be adequate. In this study we aimed to assess the serum levels of 25-hydroxivitamin D (25OHD), parathormone (PTH) and ionized calcium (Cai), as well as to analyze the prevalence of both hypovitaminosis D and secondary hyperparathyroidism in the elderly living in the city of São Paulo. We studied 177 inpatients (125 women and 52 men) with mean age (SD) 76.6 (9.0) years, and 243 outpatients (168 women and 75 men) aged 79.1 (5.9) years. In this assessment 71.2% in the inpatients group and 43.8% in the outpatients group had 25OHD levels below the minimum recommended (50 nmol/l), with the women presenting with levels considerably lower than the men. Secondary hyperparathyroidism occurred in 61.7% of the inpatients and in 54% of the outpatients. Considering the results achieved, we recommend vitamin D supplementation in effective doses for the Brazilian elderly population, in addition to suggesting a discussion for the implementation of vitamin D-enhanced food policies, particularly oriented to the ones at a greater risk.A ocorrência de fraturas osteoporóticas em idosos está relacionada às concentrações reduzidas de vitamina D e conseqüente hiperparatiroidismo secundário, sendo os institucionalizados de maior risco. No Brasil, por seu alto grau de insolação, infere-se que a quantidade de vitamina D da população seja adequada. Neste estudo, objetivamos avaliar as concentrações plasmáticas de 25-hidroxivitamina D (25OHD), paratormônio (PTH) e cálcio ionizado (Cai), assim como analisar a prevalência de hipovitaminose D e de hiperparatiroidismo secundário em idosos moradores da cidade de São Paulo. Estudamos 177 pacientes institucionalizados (125 mulheres e 52 homens) com idade média (DP) de 76,6 (9,0) anos, e 243 idosos ambulatoriais (168 mulheres e 75 homens) com 79,1 (5,9) anos. Nesta avaliação, 71,2% do grupo institucionalizado e 43,8% do ambulatorial possuíam valores de 25OHD menores do que o mínimo recomendado (50 nmol/l), sendo que as mulheres apresentaram valores consideravelmente mais baixos que os homens. O hiperparatiroidismo secundário ocorreu em 61,7% dos pacientes institucionalizados e em 54% dos ambulatoriais. Considerando os resultados obtidos, recomendamos a suplementação com doses eficientes de vitamina D para a população idosa brasileira, alem de sugerir uma discussão para a implementação de políticas de fortificação alimentar com vitamina D, especialmente direcionada àqueles com maior risco.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de EndocrinologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de GeriatriaUniversidade Federal do Paraná Serviço de EndocrinologiaUNIFESP, EPM, Depto. de EndocrinologiaUNIFESP, EPM, Depto. de GeriatriaSciEL

Soil organisms in organic and conventional cropping systems.

Apesar do crescente interesse pela agricultura orgânica, são poucas as informações de pesquisa disponíveis sobre o assunto. Assim, num Argissolo Vermelho-Amarelo distrófico foram comparados os efeitos de sistemas de cultivo orgânico e convencional, para as culturas do tomate (Lycopersicum esculentum) e do milho (Zea mays), sobre a comunidade de organismos do solo e suas atividades. As populações de fungos,bactérias e actinomicetos, determinadas pela contagem de colônias em meio de cultura, foram semelhantes para os dois sistemas de produção. A atividade microbiana, avaliada pela evolução de CO2, manteve-se superior no sistema orgânico, sendo que em determinadas avaliações foi o dobro da evolução verificada no sistema convencional. O número de espécimes de minhoca foi praticamente dez vezes maior no sistema orgânico. Não foi observada diferença na taxa de decomposição de matéria orgânica entre os dois sistemas. De modo geral, o número de indivíduos de microartrópodos foi superior no sistema orgânico do que no sistema convencional, refletindo no maior índice de diversidade de Shannon. As maiores populações de insetos foram as da ordem Collembola, enquanto para os ácaros a maior população foi a da superfamília Oribatuloidea. Indivíduos dos grupos Aranae, Chilopoda, Dyplopoda, Pauropoda, Protura e Symphyla foram ocasionalmente coletados e de forma similar entre os sistemas