RESUMO

Scaling ionic charges has become an alternative to polarizable force fields for representing indirect charge transfer effects in molecular simulations. In our work, we apply molecular dynamics simulations to investigate the properties of NaCl aqueous solutions in homogeneous and confined media. We compare classical integer- and scaled-charge force fields for the ions. In the bulk, we validate the force fields by computing equilibrium and transport properties and comparing them with experimental data. Integer-charge ions overestimate dielectric saturation and ionic association. Both force fields present an excess in ion-ion correlation, which leads to a deviation in the ionic conductivity at higher ionic strengths. Negatively charged quartz is used to simulate the confinement effect. Electrostatic interactions dominate counter-ion adsorption. Full-charge ions have stronger and more defined adsorption planes. We obtain the electroosmotic mobility of the solution by combining the shear plane location from non-equilibrium simulations with the ionic distribution from equilibrium simulations. From the Helmholtz-Smoluchowski equation, the zeta potential and the streaming potential coupling coefficient are computed. From an atomic-scale perspective, our molecular dynamics simulations corroborate the hypothesis of maximum packing of the Stern layer, which results in a stable and non-zero zeta potential at high salinity. The scaled-charge model representation of both properties is in excellent qualitative and quantitative agreement with experimental data. With our work, we demonstrate how useful and precise simple scaled-charge models for electrolytes can be to represent complex systems, such as the electrical double layer.

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The South American Dry Diagonal, also called the Diagonal of Open Formations, is a large region of seasonally dry vegetation extending from northeastern Brazil to northern Argentina, comprising the Caatinga, Cerrado, and Chaco subregions. A growing body of phylogeography literature has determined that a complex history of climatic changes coupled with more ancient geological events has produced a diverse and endemic-rich Dry Diagonal biota. However, the exact drivers are still under investigation, and their relative strengths and effects are controversial. Pleistocene climatic fluctuations structured lineages via vegetation shifts, refugium formation, and corridors between the Amazon and Atlantic forests. In some taxa, older geological events, such as the reconfiguration of the São Francisco River, uplift of the Central Brazilian Plateau, or the Miocene inundation of the Chaco by marine incursions, were more important. Here, we review the Dry Diagonal phylogeography literature, discussing each hypothesized driver of diversification and assessing degree of support. Few studies statistically test these hypotheses, with most support drawn from associating encountered phylogeographic patterns such as population structure with the timing of ancient geoclimatic events. Across statistical studies, most hypotheses are well supported, with the exception of the Pleistocene Arc Hypothesis. However, taxonomic and regional biases persist, such as a proportional overabundance of herpetofauna studies, and the under-representation of Chaco studies. Overall, both Pleistocene climate change and Neogene geological events shaped the evolution of the Dry Diagonal biota, though the precise effects are regionally and taxonomically varied. We encourage further use of model-based analyses to test evolutionary scenarios, as well as interdisciplinary collaborations to progress the field beyond its current focus on the traditional set of geoclimatic hypotheses.

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RESUMO

A versatile synthesis strategy for fluorescent 3-halo-4H-chromen-4-one derivatives is reported. The method involves the oxidative α-halogenation of enaminones performed by an efficient and sustainable oxidation system. The use of Oxone® in combination with KCl, KBr, or KI enables the preparation of 3-chloro-, 3-bromo-, or 3-iodo-4H-chromen-4-one in good to excellent yields, with great functional group tolerance where the protocol is amenable to gram-scale synthesis. The analysis of the photophysical properties of the presented 4H-chromen-4-one showed absorption in the UV region and fluorescence emission in the violet-to-cyan region with a relatively large Stokes shift. In solution, all compounds present a dual fluorescence emission, regardless of the solvent, assigned to a partially aromatised intramolecular charge transfer mechanism, considering the presence of a pseudo-aromatic ring in the chromone scaffold and the absence of the influence of substituent electronic features in optical behaviour.

RESUMO

The Brazilian Society of Angiology and Vascular Surgery has set up a committee to provide new evidence-based recommendations for patient care associated with chronic venous insufficiency. Topics were divided in five groups: 1. Classification, 2. Diagnosis, 3. Conservative or non-invasive treatment, 4. Invasive treatment and 5. Treatment of small vessels. This last series is closely related to the activities of Brazilian angiologists and vascular surgeons, who are heavily involved in the treatment of small superficial veins. These guidelines are intended to assist in clinical decision-making for attending physicians and health managers. The decision to follow a guideline recommendation should be made by the responsible physician on a case-by-case basis taking into account the patient's specific condition, as well as local resources, regulations, laws, and clinical practice recommendations.

A Sociedade Brasileira de Angiologia e de Cirurgia Vascular organizou uma comissão para fornecer novas recomendações baseadas em evidências sobre questões críticas de atendimento ao paciente com insuficiência venosa crônica. São abordados aqui os temas de classificação, diagnóstico, tratamento conservador, tratamento invasivo e tratamento de pequenos vasos. Esta última série está muito relacionada à atividade de angiologistas e cirurgiões vasculares, que possuem forte atuação no tratamento de pequenas veias superficiais. Estas diretrizes destinam-se a auxiliar na tomada de decisões clínicas de médicos assistentes e gestores de saúde. A decisão de seguir uma recomendação de diretriz deve ser feita pelo médico responsável caso a caso, levando em consideração a condição específica do paciente, bem como recursos locais, regulamentos, leis e recomendações de prática clínica.

RESUMO

Background: The use of compression dressings after phlebectomy is based solely on clinical experience due to the lack of a unified set of definitive recommendations, which makes clinical practice extremely heterogeneous. Objectives: To evaluate compression therapy with elastic stockings for 7 days after phlebectomy. Methods: We randomly allocated 104 lower limbs with disease classified as C1 and C2 to 1 of 2 groups: an intervention group (64 limbs) - wearing elastic compression stockings for the first 7 days after phlebectomy; or a control group (40 limbs) - given conventional bandaging for 24 hours postoperatively. We compared clinical response by analyzing the evolution of symptoms, hematoma formation, and preoperative vs. postoperative limb volume. Results: Pain (median 1.0 vs. 1.5, p=0.0320) and limb volume (mean 43.7 vs. 99.8, p=0.0071) were significantly improved in patients wearing elastic compression stockings for 7 days after phlebectomy compared with controls. Conclusions: Use of elastic compression therapy for 7 days after phlebectomy was effective for improving pain and lower limb volume.

Contexto: O uso de curativos após flebectomia é baseado apenas na experiência clínica, visto que não existe um conjunto unificado de recomendações definitivas, o que torna a prática clínica extremamente variável. Objetivos: Avaliar o uso de terapia elástica compressiva por 7 dias após flebectomia. Métodos: Cento e quatro membros inferiores, classificados como CEAP C1 e C2, foram randomizados em dois grupos: grupo de intervenção (64 membros) ­ uso de meia elástica por 24 horas após a cirurgia ­ e grupo controle (40 membros) ­ uso de curativo convencional por 7 dias após a cirurgia. A resposta clínica foi comparada por meio de análise da evolução dos sintomas, de hematoma e do volume dos membros antes e depois da cirurgia. Resultados: Os pacientes submetidos a terapia compressiva elástica apresentaram melhora significativa na dor (mediana 1,0 vs. 1,5; p=0,0320) e no volume dos membros (média 43,7 vs. 99,8; p=0,0071) em comparação ao grupo controle. Conclusões: O emprego da terapia compressiva elástica por 7 dias após flebectomia mostrou-se efetivo na melhora da dor e do volume dos membros inferiores.

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In this study, we present the synthesis of benzimidazo[1,2-a] quinoline-based heterocycles bearing organosulfur and organoselenium moieties through transition-metal-free cascade reactions involving a sequential intermolecular aromatic nucleophilic substitution (SNAr). Both sulfur and selenium derivatives presented absorption maxima located around 355 nm related to spin and symmetry allowing electronic 1π-π* transitions, and fluorescence emission at the violet-blue region (~440 nm) with relatively large Stokes shift. The fluorescence quantum yields were slightly influenced by the chalcogen, with the sulfur derivatives presenting higher values than the selenium analogs. In this sense, the quantum yields for selenium derivatives can probably be affected by the intersystem crossing or even the photoinduced electron transfer process (PET). The compounds were successfully applied in all-solution-processed organic light-emitting diodes (OLEDs), where poly(9-vinylcarbazole) was employed as a dispersive matrix generating single-layer device cells. The obtained electroluminescence spectra are a sum of benzimidazo[1,2-a]quinolines and PVK singlet and/or triplet emissive states, according to their respective energy band gaps. The best diode rendered a luminance of 25.4 cd⋅m-2 with CIE (0.17, 0.14) and current efficiency of 20.2 mcd⋅A-1, a fivefold improvement in comparison to the PVK device that was explained by a 50-fold increase of charge-carriers electrical mobility.

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The components of a fluid mixture may segregate due to the Soret effect, a coupling phenomenon in which mass flux can be induced by a thermal gradient. In this work, we evaluate systematically the thermodiffusion of the CO2-H2O mixture, and the influence of the geothermal gradient on CO2 segregation in deep saline aquifers in CO2 storage. The eHeX method, a nonequilibrium molecular dynamics simulation approach, is judiciously selected to simulate the phenomenon. At 350 K, 400 bar, and CO2 mole fraction of 0.02 (aquifer conditions), CO2 accumulates on the cold side, and the thermal diffusion factor is close to 1 in a number of force fields. The lower the temperature, the higher is the separation and the thermal diffusion factor. In colder regions, water self-association is stronger, whereas the CO2-H2O cross-association and the CO2-CO2 interactions enhance at higher temperatures. Thermodiffusion and gravitational segregation have opposite effects on CO2 segregation. At typical subsurface conditions, the Soret effect is more pronounced than gravity segregation, and CO2 concentrates in the top (colder region). Our work sets the stage to model the effect of electrolytes on CO2 segregation in subsurface aquifers and other areas of interest.

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We previously showed that L. (Leishmania) amazonensis promastigotes and amastigotes of the PH8 strain generated larger lesions in mice than LV79, and that lesion-derived amastigotes from the two strains differ in their proteomes. We recently reported that PH8 promastigotes are more phagocytized by macrophages. Promastigotes' membrane-enriched proteomes showed several differences, and samples of each strain clustered based on proteomes. In this paper, we show phenotypic differences between PH8 and LV79 promastigotes that may explain the higher virulence of PH8. We compared in vitro macrophage infections by day 4 (early) and day 6 (late stationary phase) cultures, resistance to complement, and LPG characteristics. PH8 promastigotes showed a higher infectivity and were more resistant to murine complement. LPG was different between the strains, which may influence the interaction with macrophages and survival to complement. We compared the infection of the permissive vector Lutzomyia longipalpis. PH8 was more abundant in the vector's gut 72 h after feeding, which is a moment where blood digestion is finished and the parasites are exposed to the gut environment. Our results indicate that PH8 promastigotes are more infective, more resistant to complement, and infect the permissive vector more efficiently. These data suggest that PH8 is probably better adapted to the sand fly and more prone to survive in the vertebrate host.

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The aim of this study was to improve our knowledge about carcinogenesis and lifestyle, given their impact on the occurrence of breast cancer, emphasizing the importance of lifestyle changes as a preventive factor in the development of the disease. We conducted a bibliographic review with the analysis of 31 articles in English and Portuguese. As a result, the articles selected for study showed that factors such as diet, alcohol intake, smoking, obesity, physical activity, occupational exposure, hormonal factors (hormone therapy, contraceptives) and reproductive factors (menarche, menopause, nulliparity, pregnancy, breastfeeding) have a protective or risk effect on breast cancer. We conclude that eating healthy, with fruits, vegetables and greens, practicing moderate physical activity, avoiding alcoholic beverages and breastfeeding exclusively reduce the risk of developing breast cancer by 28%. Therefore, it is necessary to make the public aware of these modifiable risk factors

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RESUMO

Abstract It is repeatedly stressed the need to characterize the extant biodiversity in tropical ecosystems. However, inventory studies are still progressing slowly in dry ecosystems, leading to the underestimation of their true biodiversity and hindering conservation efforts. In this study, we present primary and secondary data, along with an updated list of amphibians and reptiles from two localities in the São Francisco-Gurguéia region in Piauí. Additionally, we compare the species composition between nine areas within the Caatinga, which were sampled using standardized methods over the past ten years, to examine broader spatial patterns of community composition. To survey reptiles and amphibians, we employed similar methods and sampling efforts in two areas within the Serra das Confusões National Park (SCNP) region. Our surveys recorded a total of 73 species of amphibians and reptiles, of which 24 are new distribution records for the SCNP region. Consequently, our findings increase the known herpetofauna in the region to 94 species. Despite their proximity, the two sites in the SCNP region exhibited only 42% similarity in species composition, and they differed significantly from other areas within the Caatinga. Furthermore, even the closer Caatinga areas presented differences in species composition, highlighting the necessity to evaluate biodiversity across the landscape and contribute to understanding biogeographic patterns.

Resumo É repetidamente enfatizada a necessidade de caracterizar a biodiversidade vivente em ecossistemas tropicais. No entanto, os estudos de inventário ainda estão progredindo lentamente em ecossistemas secos, levando à subestimação de sua verdadeira biodiversidade e dificultando os esforços de conservação. Neste estudo, apresentamos dados primários e secundários, juntamente com uma lista atualizada de anfíbios e répteis de duas localidades na região de São Francisco-Gurguéia, do Piauí. Além disso, comparamos a composição de espécies entre nove áreas dentro da Caatinga, que foram amostradas usando métodos padronizados nos últimos dez anos, para examinar padrões espaciais mais amplos de composição da comunidade. Para estudar répteis e anfíbios, utilizamos métodos e esforços de amostragem semelhantes em duas áreas na região do Parque Nacional da Serra das Confusões (PNSC). Nossos levantamentos registraram um total de 73 espécies de anfíbios e répteis, das quais 24 são novos registros de distribuição para a região do PNSC. Consequentemente, nossos resultados aumentam a herpetofauna conhecida na região para 94 espécies. Apesar da proximidade, os dois locais na região do PNSC exibiram apenas 42% de similaridade na composição de espécies e diferiram significativamente de outras áreas dentro da Caatinga. Mesmo áreas mais próximas da Caatinga apresentaram diferenças na composição de espécies, destacando a necessidade de avaliar a biodiversidade em toda a paisagem e contribuir para a compreensão de padrões biogeográficos.