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This article presents an experimental study to analyze the mechanical properties of a soil stabilized with ordinary Portland cement (OPC) under a sustainable approach consisting of a significant substitution of OPC for sugarcane bagasse ash (SCBA) to reduce the quantity of cement used in the stabilization, reaching the necessary mechanical requirements for its use as a subgrade layer. Soil specimens were elaborated with 3%, 5%, and 7% OPC as a stabilizing agent by weight of the soil. These mixtures were then partially substituted with 25%, 50%, and 75% SCBA, with these percentages being by weight of the stabilizer (OPC). Compaction, compressive strength, and California bearing ratio (CBR) tests were performed to evaluate the mechanical properties of the specimens. The results indicate that a 25% substitution of OPC by SCBA shows a similar performance to the mixture with only Portland cement, so a reduction in OPC use can be made. Further, with a substitution of 100% OPC by SCBA, the CBR of natural soil without stabilizers is improved.

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Novel green concrete (GC) admixtures containing 50% and 100% recycled coarse aggregate (RCA) were manufactured according to the ACI 211.1 standard. The GC samples were reinforced with AISI 1080 carbon steel and AISI 304 stainless steel. Concrete samples were exposed to 3.5 wt.% Na2SO4 and control (DI-water) solutions. Electrochemical testing was assessed by corrosion potential (Ecorr) according to the ASTM C-876-15 standard and a linear polarization resistance (LPR) technique following ASTM G59-14. The compressive strength of the fully substituted GC decreased 51.5% compared to the control sample. Improved corrosion behavior was found for the specimens reinforced with AISI 304 SS; the corrosion current density (icorr) values of the fully substituted GC were found to be 0.01894 µA/cm2 after Day 364, a value associated with negligible corrosion. The 50% RCA specimen shows good corrosion behavior as well as a reduction in environmental impact. Although having lower mechanical properties, a less dense concrete matrix and high permeability, RCA green concrete presents an improved corrosion behavior thus being a promising approach to the higher pollutant conventional aggregates.

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Resumen Los linfomas de las glándulas salivales son una entidad e incidencia rara. La localización más frecuente es la glándula parótida, seguida de las glándulas submandibular y sublingual. La mayoría de los linfomas parótidos son linfomas no Hodgkin y se consideran derivados de tejido linfoide asociado a la mucosa (MALT). De manera poco frecuente, estos casos se han notificado y con frecuencia se diagnostican de manera inadecuada, ya que su presentación es relativamente benigna, comportamiento localizado, crecimiento lento y varios años de evolución.

Abstract Lymphomas of the salivary glands are a rare entity with a rare incidence. They are more commonly found on the parotid gland, followed by the submandibular and sublingual glands. The majority of parotid lymphomas are non-Hodgkin's lymphomas and are considered to be derived from mucosal-associated lymphoid tissue (MALT). Reports of these cases are scarce and often misdiagnosed since: their manifestation is relatively benign, they have a localized behavior, a slow growth and the evolution takes several years.

RESUMO

In this study, ternary ecological concrete (TEC) mixtures were produced with partial substitution of the ordinary Portland cement (OPC) by 10%, 20%, and 30% of sugar cane bagasse ash (SCBA) and silica fume (SF); a control mixture (100% OPC) was prepared according to ACI 211.1 standard. The studied TEC specimens were reinforced with AISI 304 stainless steel and AISI 1018 carbon steel rebars. TEC reinforced specimens were immersed in two different electrolytes, a control (DI-water) and 3.5 wt.% MgSO4 solution, for 180 days. The electrochemical corrosion was monitored by corrosion potential (Ecorr) according to ASTM C-876-15 standard, and the linear polarization resistance (LPR) technique using ASTM G59 standard. The Ecorr and current density icorr results show that AISI 304 stainless steel rebars have a high corrosion resistance, with icorr values below 0.1 µA/cm2, which is interpreted as a level of negligible corrosion. The best corrosion performance was found for the TEC mixture made with a 20% addition of blend of sugar cane bagasse ash-silica fume (SCBA-SF) to the OPC.

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Resumen En la insuficiencia cardiaca terminal los síntomas predominantes habitualmente están relacionados con la congestión; sin embargo, la resistencia a diuréticos vía oral es frecuente y necesita tratamiento parenteral para paliar los síntomas. La administración intravenosa de furosemida requiere hospitalización o asistencia hospitalaria, lo que supone un deterioro significativo de la calidad de vida de pacientes en fases avanzadas de la enfermedad. La administración subcutánea continua de furosemida mediante infusor elastomérico es una técnica eficaz con baja tasa de complicaciones graves que permite la administración de diurético parenteral en el ámbito domiciliario, y evita la necesidad de hospitalizar. A pesar de que esta modalidad de tratamiento no está aceptada en ficha técnica y requiere más estudios que precisen su indicación, puede suponer un recurso adecuado para pacientes seleccionados. Se presenta el caso de una paciente con insuficiencia cardiaca avanzada, síntomas congestivos y ausencia de respuesta a tratamiento deplectivo vía oral, tratada con perfusión continua subcutánea domiciliaria de furosemida mediante infusor elastomérico de forma prolongada.

Abstract In end-stage heart failure the predominant symptoms are usually associated with congestion. However, the resistance to oral diuretics is common and requires parenteral treatment to alleviate the symptoms. The intravenous administration of furosemide requires hospital admission or hospital care. This leads to a significant decrease in the quality of life of patients in advance stages of the disease. The continuous subcutaneous infusion of furosemide using an elastomeric pump is an effective technique, with a low rate of serious complications that allows a parenteral diuretic to be administered in the home environment and thus avoiding the need for hospital admission. Despite this mode of treatment not being indicated in the drug data sheet, and requires more studies that specify its indication, it may be a suitable recourse for selected patients. It is presented a case of a patient with advanced heart failure, congestive symptoms, and a lack of response to oral diuretics treatment, and then treated with a continuous and prolonged subcutaneous infusion of furosemide at home using an elastomeric infusion pump.

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RESUMO

The use of supplementary cementitious materials such as fly ash, slag, and silica fume improve reinforced concrete corrosion performance, while decreasing cost and reducing environmental impact compared to ordinary Portland cement. In this study, the corrosion behavior of AISI 1018 carbon steel (CS) and AISI 304 stainless steel (SS) reinforcements was studied for 365 days. Three different concrete mixtures were tested: 100% CPC (composite Portland cement), 80% CPC and 20% silica fume (SF), and 80% CPC and 20% fly ash (FA). The concrete mixtures were designed according to the ACI 211.1 standard. The reinforced concrete specimens were immersed in a 3.5 wt.% NaCl test solution to simulate a marine environment. Corrosion monitoring was evaluated using the corrosion potential (Ecorr) according to ASTM C876 and the linear polarization resistance (LPR) according to ASTM G59. The results show that AISI 304 SS reinforcements yielded the best corrosion behavior, with Ecorr values mainly pertaining to the region of 10% probability of corrosion, and corrosion current density (icorr) values indicating passivity after 105 days of experimentation and low probability of corrosion for the remainder of the test period.

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Acetogenins are among the most potent of the known inhibitors of complex I (NADH-ubiquinone oxidoreductase) in mitochondrial electron transfer system. Elucidation of the dynamic function of the alkyl spacer linking the two toxophores (i.e., the hydroxylated tetrahydrofuran and the γ-lactone rings) is critical for fully understanding their inhibition mechanism. To this end, using molecular dynamics simulations a structure-activity relationship study of a series of acetogenins was performed for the first time using this approach. Our results clearly indicated that both, the length and the molecular flexibility of the spacer, were crucial for taking an active conformation. A partially folded conformation with an optimal length (bis-tetrahydrofuran rings and 13 carbon atoms) of about 16 Šwith a high molecular flexibility might depict an active form of the spacer. In addition, we demonstrated that the bis-tetrahydrofuran derivatives are able to overcome the shortage of the length of the spacer more efficiently than the mono-tetrahydrofuran derivatives with the help of the additional tetrahydrofuran, which acts as a pseudospacer. Our results obtained from molecular dynamics calculations supported the use of a combined decane/water system as a good solvent model to simulate the biological environment of acetogenins acting as inhibitor of complex I.

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