Abstract Peripartum cardiomyopathy (PPCM) is a rare but life-threatening condition defined by left ventricular dysfunction and heart failure (HF), occurring in late pregnancy or, more commonly, the early postpartum period. In African American women, women with pre-eclampsia, advanced maternal age, and numerous gestation pregnancies, there is a greater incidence. Although the pathophysiology of PPCM is still undetermined, the importance of vasculo-hormonal pathways has been suggested in research over the past decades. Sarcomere genetic polymorphisms are found in at least some women with the disorder. More than 50% of the patients recover systolic function, albeit some are left with chronic cardiomyopathy, and a small minority of patients requires mechanical support or cardiac transplantation, or both. For the diagnosis of PPCM, electrocardiographic findings of decreased myocardial function are essential. Currently, the management of PPCM is limited to standard treatments for HF with reduced ejection fraction, with attention to minimizing the potential adverse effects on the fetus in women who are still pregnant. As a result, the outcome might range from full recovery to persistent HF, arrhythmia, thromboembolic events, or death. Research on PPCM is examined in this review, as are potential future paths for further study.

Resumen La miocardiopatía periparto (PPCM) es una afección rara pero potencialmente mortal que se define por disfunción ventricular izquierda e insuficiencia cardíaca (IC), que ocurre al final del embarazo o, más comúnmente, al comienzo del período posparto. En mujeres afroamericanas, mujeres con preeclampsia, edad materna avanzada y gestaciones numerosas, existe una mayor incidencia. Aunque la fisiopatología de la PPCM aún no se ha determinado, la importancia de las vías vasculohormonales se ha sugerido en la investigación durante las últimas décadas. Los polimorfismos genéticos del sarcómero se encuentran en algunas mujeres afectas con el trastorno. Más del 50% de los pacientes recuperan la función sistólica, aunque algunos quedan con miocardiopatía crónica y, una pequeña minoría de pacientes, requiere soporte mecánico, trasplante cardíaco, o ambos. Para el diagnóstico de PPCM, los hallazgos electrocardiográficos de función miocárdica disminuida son esenciales. Actualmente, el manejo de la PPCM se limita a los tratamientos estándar para la IC con fracción de eyección reducida, con atención a minimizar los posibles efectos adversos sobre el feto en mujeres que aún están embarazadas. Como resultado, el resultado puede variar desde una recuperación total hasta insuficiencia cardíaca persistente, arritmia, eventos tromboembólicos o muerte. En esta revisión se examina la investigación sobre la PPCM, así como las posibles vías futuras para estudios adicionales.

Abstract Increase of energy absorption along with smooth load displacement curve, reduced peak force and high mean crushing force is the key in the modern dynamic design of structures. In this regard, a new metallic tubular configuration consisting of uni-sectional bi-tubular inner tubes, with outer tubes of multiple varied cross-sections is proposed and crushed under axial dynamic loading. A number of configurations are proposed ranging from simple to complex polygonal sections defined in three groups. Deformation modes and energy absorption characteristics such as peak crushing force, mean crushing force, and specific energy absorption are determined and discussed for each configuration. The proposed arrangement shows a stable crushing and higher values of crush force efficiency. In order to select the most suitable configuration, on the basis of maximum specific energy absorption, peak crushing force and minimum peak force, a robust decision making method known as Complex Proportional Assessment (COPRAS) is implemented. The optimal configuration in each group is determined on the basis of higher values of specific energy absorption, crush force efficiency and a lower value of peak crushing force, using the chosen weighting factors in COPRAS implementation. Finally, the configuration with inner and outer hexagonal tubes is found to be the best possible design concept among the top members of each group, with peak crushing force, mean crushing force and crush force efficiency values of 69.8 KN, 7.3 KJ and 0.75, respectively.

Abstract Thin walled multi-cell columns are highly efficient energy absorbers under axial compressions. Multi-cell features are usually obtained by placing stiffeners or ribs to get the required geometry features in the columns. In this study, the curved stiffeners with varying numbers in different configurations are used to support the circular single and bi-tubular metallic tubes and their shape, position and number effects are numerically investigated under dynamic axial crushing loads. Number of configurations can be classified by the number of tube/tubes and curved stiffened shells. This study can be divided in three parts; single tubes with cross-curved stiffeners with equal number of cells, single tubes with curved stiffened wall supports with ascending number of stiffeners, and bi-tubular tubes with ascending cross-curved stiffeners. The mass in each configuration is maintained as same by adjusting the thicknesses of the stiffeners. Energy absorption for all of the configurations are compared with published experimental literature of standard single tube and single tube with cross-straight stiffeners. Deformation modes and energy absorption characteristics are evaluated and discussed for all of the proposed configurations. Results indicate that the proposed configurations with curvy stiffeners are superior in energy absorption with increased mean crushing force and enhanced energy absorption along with a high value of crush force efficiency in comparison with the refernce configurations. Bi-tubular configurations with curvy stiffeners show a more stabalized response with the lowest peak crushing force in all of the proposed configurations.

Abstract Thin walled multi-cell columns are highly efficient energy absorbers under axial compressions. Multi-cell features are usually obtained by placing stiffeners or ribs to get the required geometry features in the columns. In this study, the curved stiffeners with varying numbers in different configurations are used to support the circular single and bi-tubular metallic tubes and their shape, position and number effects are numerically investigated under dynamic axial crushing loads. Number of configurations can be classified by the number of tube/tubes and curved stiffened shells. This study can be divided in three parts; single tubes with cross-curved stiffeners with equal number of cells, single tubes with curved stiffened wall supports with ascending number of stiffeners, and bi-tubular tubes with ascending cross-curved stiffeners. The mass in each configuration is maintained as same by adjusting the thicknesses of the stiffeners. Energy absorption for all of the configurations are compared with published experimental literature of standard single tube and single tube with cross-straight stiffeners. Deformation modes and energy absorption characteristics are evaluated and discussed for all of the proposed configurations. Results indicate that the proposed configurations with curvy stiffeners are superior in energy absorption with increased mean crushing force and enhanced energy absorption along with a high value of crush force efficiency in comparison with the refernce configurations. Bi-tubular configurations with curvy stiffeners show a more stabalized response with the lowest peak crushing force in all of the proposed configurations.

Microwave assisted synthesis of a series of 4-hydroxy-N'-(phenylcarbonyl)-2H-1,2-benzothiazine-3-carbohydrazide 1,1-dioxides from sodium saccharin is reported. Sodium o-benzosulfimide was N-alkylated with ethyl chloroacetate followed by base catalyzed ring expansion to six membered 1,2-benzothiazine through Gabriel-Coleman type rearrangement yielding ethyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide. It was later condensed with a series of benzohydrazides synthesized from various carboxylic acids to get the title compounds. All the synthesized compounds were subjected to preliminary evaluation for their biological activity against series of Gram positive, Gram negative bacteria and fungi. Some of the compounds showed marked activity against the selected microorganisms.