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In this study, we report the enhanced electrochemical performance of a MnO2 electrode modified with a pH-sensitive co-polymer, activated at acidic pH, and designed to counteract MnO2 degradation in aqueous aqueous pseudocapacitors. The conformation of this polymer is controlled by the local pH changes that occur at the electrode/electrolyte interface during electrochemical stress associated to oxygen evolution.As a proof of concept, we demonstrate that the addition of the pH-sensitive polymer contributes to improved electrode integrity and lifetime under over-polarization with oxygen evolution. After undergoing 10 cycles of electrochemical stress, the MnO2/pH-sensitive polymer composite retains ∼ 70 % of its capacitance. This remarkable result stands in stark contrast with the pristine MnO2 electrode which fails catastrophically under the same stress conditions. We believe that this pH-induced self-protection mechanism represents a significant advancement in the development of novel smarter self-healing electroactive materials for the next generation of energy storage devices.

The need for new therapeutic approaches for triple-negative breast cancer is a clinically relevant problem that needs to be solved. Using a multi-targeting approach to enhance cancer cell uptake, we synthesized a new family of ruthenium(II) organometallic complexes envisaging simultaneous active and passive targeting, using biotin and polylactide (PLA), respectively. All compounds with the general formula, [Ru(η5-CpR)(P)(2,2′-bipy-4,4′-PLA-biotin)][CF3SO3], where R is -H or -CH3 and P is P(C6H5)3, P(C6H4F)3 or P(C6H4OCH3)3, were tested against triple-negative breast cancer cells MDA-MB-231 showing IC50 values between 2.3–14.6 µM, much better than cisplatin, a classical chemotherapeutic drug, in the same experimental conditions. We selected compound 1 (where R is H and P is P(C6H5)3), for further studies as it was the one showing the best biological effect. In a competitive assay with biotin, we showed that cell uptake via SMVT receptors seems to be the main transport route into the cells for this compound, validating the strategy of including biotin in the design of the compound. The effects of the compound on the hallmarks of cancer show that the compound leads to apoptosis, interferes with proliferation by affecting the formation of cell colonies in a dose-dependent manner and disrupts the cell cytoskeleton. Preliminary in vivo assays in N: NIH(S)II-nu/nu mice show that the concentrations of compound 1 used in this experiment (maximum 4 mg/kg) are safe to use in vivo, although some signs of liver toxicity are already found. In addition, the new compound shows a tendency to control tumor growth, although not significantly. In sum, we showed that compound 1 shows promising anti-cancer effects, bringing a new avenue for triple-negative breast cancer therapy.

The digital models of landform representation allow several types of geomorphological analysis, such as assessing prone areas to the mass movement. Among the data set that applied to elaborate such models, LiDAR (Light Detection and Ranging) technology has stood out due to its capacity to represent in detail terrain specific characteristics. This work aimed to present a variety of studies based on LiDAR to evaluate slope instability and to describe an interpolation test of LiDAR raw data to generate a Digital Terrain Model considering different interpolation approaches, in an area affected by shallow landslides. The results show that the tool applied is efficient when combined Triangulation to Natural Neighbor methods.

The rates of recurrent venous thromboembolism (RVTE) vary widely, and its causes still need to be elucidated. Statistical multivariate methods can be used to determine disease predictors and improve current methods for risk calculation. The objective of this study was to apply principal component analysis to a set of data containing clinical records of patients with previous venous thromboembolism and extract the main factors that predict recurrent thrombosis. Records of 39 factors including blood and lipid parameters, hereditary thrombophilia, antiphospholipid syndrome, clinical data regarding previous thrombosis and treatment, and Doppler ultrasound results were collected from 235 patients. The results showed that 13 principal components were associated with RVTE and that 18 of 39 factors are the important for the analysis. These factors include red blood cell, white blood cell, hematocrit, red cell distribution width, glucose, lipids, natural anticoagulant, creatinine, age, as well as first deep vein thrombosis data (distal/proximal, d -dimer, and time of anticoagulation). The results demonstrated that simple clinical parameters easy to be collected can be used to predict rates of recurrence and to develop new clinical decision support systems to predict the rates of RVTE.

Pré-Textuais

Os diferentes tipos de modelos têm uma relação direta com o grau de abstração da realidade, ocorrendo desde formas mais simples, concretas e específicas, em que a realidade é transformada apenas em nível de escala até a elaboração de modelos conceituais pela aplicação de formulações matemáticos. Dentre esses, os de base física, que descrevem fisicamente os processos por meio de equações, desconsiderando a subjetividade, têm sido adotados, por exemplo, em estudos de movimento de massa. Assim, esse trabalho objetiva discutir brevemente a fundamentação dos conceitos de modelos utilizados na Geografia Física, destacando dois modelos aplicados em estudos relacionados a escorregamentos e que demostraram resultados positivos em seus testes. Primeiramente foi discutido o modelo clássico de correlação entre a pluviosidade e a ocorrência de escorregamentos. Já o segundo modelo apresentado, o modelo matemático em base física, SHALSTAB, avalia a suscetibilidade de ocorrência de escorregamentos rasos. Por fim são apresentados exemplos de resultados desses modelos aplicados no Brasil.

Nota Editorial

The mathematical models physically based are important tools to indicate potentially unstable areas using geotechnical and topographic information. Therefore, a digital elevation model is essential, since it is the base to obtain information as contribution area and slope angle, considered fundamental in its application. This work aimed to evaluate the response of the mathematical model physically based SHALSTAB with different size cell (resolution) on the Digital Terrain Model (DTM) derived from conventional topographic data (contour lines) in a watershed with shallow landslide record. The results indicate that there was no significant improvement in the definition of unstable areas when the DTM grid resolution changes (10, 5 and 1m).