Shape Control of Composite Structures with Optimally Placed Piezoelectric Patches

The problem of shape control of composite laminated smart structures with piezoelectric patches placed at optimal location is considered in this thesis. Laminated plate structures with piezoelectric patches for shape control applications are modeled using a shear deformable plate formulation by including the piezoelectric layers into the plate substrate. A composite plate finite element model is also developed for composite plates with self-sensing actuators. Non-linear hysteresis models for piezoelectric materials are presented and discussed. Numerical simulation of composite plate structures with piezoelectric actuators is conducted and presented. The optimization problem of finding the optimal location of actuators using a linear quadratic control algorithm is done and the results are discussed. Static shape control strategies are also discussed

A case-control study of serum and tissue catalase among morphological variants of vitiligo

Background: Role of oxidative stress in the pathogenesis of vitiligo. Aim: Estimation of serum and tissue catalase levels in morphological variants of vitiligo. Settings and Design: A prospective case-control study was conducted in the outpatient department of Dermatology in Safdarjung hospital. Materials and Methods: We estimated levels of serum and tissue catalase in 30 vitiligo patients and 30 matched healthy controls. Statistical Analysis: The data analysis was done in Statistical Package for Social Sciences (SPSS) version 21.0. Normality of data was tested by Kolmogorov–Smirnov test. Results: Serum and tissue catalase was lower in vitiligo patients than controls. Serum catalase was lowest in vulgaris type, whereas in the acrofacial type had lowest tissue catalase levels. Conclusion: Vitiligo patients have a generalized oxidative stress functioning at a higher pace as seen with decreased serum and tissue CAT which can well be taken as a marker of active disease and they can be helped with topical pseudoCAT preparations

In vitro-microenvironment directs preconditioning of human chorion derived MSC promoting differentiation of OPC-like cells.

The loss of oligodendrocyte progenitor cells (OPC) is a hallmark of perinatal brain injury. Our aim was to develop an in vitro culture condition for human chorion-derived mesenchymal stem cells (MSC) that enhances their stem cell properties and their capability to differentiate towards OPC-like cells. MSC were grown either in serum replacement medium (SRM) or serum-containing medium (SM) and tested for their morphology, proliferation, secretome, migration, protein expression and differentiation into OPC-like cells. MSC cultured in SRM condition have distinct morphology/protein expression profile, increased cell proliferation/migration and capacity to differentiate into OPC-like cells

Corrosion protection of mild steel by a new phosphonate inhibitor system in aqueous solution

A protective film has been developed on the surface of the mild steel in low chloride aqueous environment using a synergistic mixture of an eco friendly inhibitor, imino dimethyl phosphonic acid (IDMPA) and Zn2+. The synergistic effect of IDMPA in controlling corrosion of the mild steel has been investigated by gravimetric and electrochemical studies in the presence of Zn2+. The formulation consisting of IDMPA and Zn2+ has excellent inhibition efficiency. The mixed mode of inhibition studied by potentiodynamic polarization and electrochemical impedance spectroscopy has shown that the changes in the impedance parameters like charge transfer resistance (Rct) and constant phase element (CPE) confirm the strong adsorption on the mild steel. Surface characterization inspection using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) is used to ascertain the nature of the protective film. The mechanistic aspects of corrosion inhibition are proposed

Perceptions About E-Learning Among Undergraduate Medical Students: A Cross Sectional Study

The COVID-19 pandemic times showed the need for blending e-learning in medical education. The current study aims to find the perceptions of undergraduate medical students on e-learning. A questionnaire-based cross-sectional study was conducted on 848 students on perceptions about e-learning. Private college students and Phase IV students significantly faced more data exhaustion. The government college students and phase IV students significantly felt that classes were more monotonous. The longer duration of e-learning caused health effects. Thus, to bring about a better learning environment e-learning can be integrated into the MBBS curriculum as a supplement to bedside and small group learning

Exploring the Electronic Properties of Ribonucleic Acids Integrated Within a Schottky-Like Junction

Deoxyribonucleic acid (DNA), being the main biomolecule of life, has been studied extensively in terms of its electronic properties, charge transport mechanisms and potential use in nano-electronic devices. The ability of DNA to self-replicate, self-assemble and mediate charge transfer has made it an interesting molecule to multidisciplinary researchers. However, not much attention has been given to ribonucleic acid (RNA), which is an equally important biomolecule that shares some common features with DNA. Elucidation of RNA’s electronic behavior could provide more information regarding its electronic properties, potentially offering a new biomolecule for application in bioelectronics. In this work, RNA samples integrated within two metal electrodes were subjected to positive and negative bias potentials and their resulting current profiles were investigated. Interestingly, current rectification similar to electric field-induced semi-conductive behavior of conventional Schottky junctions was observed for all RNA samples tested, indicating highly characteristic RNA-specific Schottky profiles. A non-linear profile was observed from the current–voltage (I–V) characteristics of gold (Au)-RNA-Au structures showing resemblance to metal-DNA structures investigated previously. Various solid-state parameters such as turn-on voltage, shunt resistance, series resistance and ideality factor were also calculated to further understand the biomaterial’s solid-state behavior. These results successfully demonstrated the exciting observation of the semi-conductive-like behavior of RNA which could be utilized as a tool in molecular electronics. © 2019, The Minerals, Metals & Materials Society

The Cytoprotective Effects of Human Endothelial Progenitor Cell-Conditioned Medium Against an Ischemic Insult Are Not Dependent on VEGF and IL-8.

Endothelial progenitor cells (EPCs) promote revascularization and tissue repair mainly by paracrine actions. In the present study, we investigated whether EPC-secreted factors in the form of conditioned medium (EPC-CM) can protect cultured brain microvascular endothelial cells against an ischemic insult. Furthermore, we addressed the type of factors that are involved in the EPC-CM-mediated functions. For that purpose, rat brain-derived endothelial cells (rBCEC4 cell line) were exposed to EPC-CM pretreated with proteolytic digestion, heat inactivation, and lipid extraction. Moreover, the involvement of VEGF and IL-8, as canonical angiogenic factors, was investigated by means of neutralizing antibodies. We demonstrated that EPC-CM significantly protected the rBCEC4 cells against an ischemic insult mimicked by induced oxygen-glucose deprivation followed by reoxygenation. The cytoprotective effect was displayed by higher viable cell numbers and reduced caspase 3/7 activity. Heat inactivation, proteolytic digestion, and lipid extraction resulted in a significantly reduced EPC-CM-dependent increase in rBCEC4 viability, tube formation, and survival following the ischemic challenge. Notably, VEGF and IL-8 neutralization did not affect the actions of EPC-CM on rBCEC4 under both standard and ischemic conditions. In summary, our findings show that paracrine factors released by EPCs activate an angiogenic and cytoprotective response on brain microvascular cells and that the activity of EPC-CM relies on the concerted action of nonproteinaceous and proteinaceous factors but do not directly involve VEGF and IL-8

Improving retinal vascular endothelial cell tropism through rational rAAV capsid design.

Vascular endothelial cells (VEC) are essential for retinal homeostasis and their dysfunction underlies pathogenesis in diabetic retinopathy (DR) and exudative age-related macular degeneration (AMD). Studies have shown that recombinant adeno-associated virus (rAAV) vectors are effective at delivering new genetic material to neural and glial cells within the retina, but targeting VECs remains challenging. To overcome this limitation, herein we developed rAAV capsid mutant vectors with improved tropism towards retinal VEC. rAAV2/2, 2/2[QuadYF-TV], and rAAV2/9 serotype vectors (n = 9, capsid mutants per serotype) expressing GFP were generated by inserting heptameric peptides (7AA) designed to increase endothelial targeting at positions 588 (2/2 and 2/2[QuadYF-TV] or 589 (2/9) of the virus protein (VP 1-3). The packaging and transduction efficiency of the vectors were assessed in HEK293T and bovine VECs using Fluorescence microscopy and flow cytometry, leading to the identification of one mutant, termed EC5, that showed improved endothelial tropism when inserted into all three capsid serotypes. Intra-ocular and intravenous administration of EC5 mutants in C57Bl/6j mice demonstrated moderately improved transduction of the retinal vasculature, particularly surrounding the optic nerve head, and evidence of sinusoidal endothelial cell transduction in the liver. Most notably, intravenous administration of the rAAV2/2[QuadYF-TV] EC5 mutant led to a dramatic and unexpected increase in cardiac muscle transduction

Utilization of modern menstrual methods and related unmet needs among college going women in Coimbatore district: a descriptive cross-sectional study

Abstract Objectives The primary objectives were to determine the proportion of modern menstrual method (MMM) users among college going women in Coimbatore district, Tamil Nadu; and to estimate the unmet needs associated with use of MMMs in comparison with other menstrual hygiene methods (MHMs). We also assessed the factors that determine MMM use among college going women. Methods This was a descriptive cross-sectional study conducted among college going women in Coimbatore district, Tamil Nadu, India between October 2022 and January 2023 using a purpose predesigned, pretested, semi-structured proforma that included validated Menstrual Practice Needs Scale (MPNS-36). Results Only 1.4% of the study participants used MMMs – menstrual cups (1.3%) and tampons (0.1%). Sanitary pads were the most common MHM of choice (96.3%); of which majority (98.6%) used disposable pads and more than half (50.4%) used non-biodegradable pads. Importantly, one in six (16.5%) were not aware of nature of sanitary pads (biodegradable or nonbiodegradable) used. The unmet needs associated with MMMs (menstrual cups and tampons) were significantly lower than that for other MHMs (including sanitary pads), in particular, the unmet material and home environment needs, unmet material reliability concerns, unmet reuse needs and unmet reuse insecurity. However, we found no significant difference between MMMs, sanitary pads and other MHMs in terms of unmet transport, college environment, change and disposal insecurity needs. The significant predictors of use of MMMs were age (more than 21 years of age), residence (urban), type of stay (off campus including home), socioeconomic status (upper), fathers’ and mothers’ education (high school and above), and presence of personal income. Discussions with friends (or peers) both before and after menarche regarding menstruation resulted in higher adoption of modern menstrual methods. Conclusion MMMs provided comparative advantage with lesser unmet needs for material reliability and reuse insecurity concerns, particularly in home environment. However, none of the MHMs fulfilled the user expectations for transport and disposal insecurity concerns, particularly outdoors