Extension of effective medium theory to three-component system—two conductive particle types in the polymer matrix

A foundation is presented for the extension of the normal effective medium theory (for a two-component system (filler and polymer matrix)) to a three-component system (two filler species and matrix). No experimental test of the improved theory is made here, but some general trends are confirmed by other experiments. The theory is sufficiently general to allow the second filler component to represent a particle of the same composition as the first filler component but of a different size, or of the same size but of a different composition. Important satellite derivations are included.     

Enhancement of dielectric and energy density properties in the PVDF‐based copolymer/terpolymer blends

We investigated the high dielectric constant and energy storage density for the blends of P(VDF‐TrFE) copolymer and P(VDF‐TrFE‐CFE) terpolymer. The degradation of coercive field (E_c) and remnant polarization (P_r) of the copolymer under an electric field of 125 MV/m was observed and the copolymer changed into a typical relaxor ferroelectric with doping of terpolymer. The dielectric constant of P(VDF‐TrFE) was found to be ～11, but was enhanced to ～55 by blending with P(VDF‐TrFE‐CFE) at 60 wt%. Consequently, a higher energy density of about 4.2 J/cm³ was obtained in these blends in contrast to about 3.6 J/cm³ in the terpolymer at the very low applied electric field of 125 MV/m. These results demonstrate the promise of blend approaches for tailoring and enhancing the dielectric properties of ferroelectric polymers. POLYM. ENG. SCI., 55:1396–1402, 2015. © 2015 Society of Plastics Engineers     

Patterning titania with the conventional and modified micromolding in capillaries technique from sol–gel and dispersion solutions

We report TiO₂ patterns obtained by a soft-lithographic technique called ‘micromolding in capillaries’ using sol–gel and dispersion solutions. A comparison between patterning with a sol–gel and dispersion solutions has been performed. The patterns obtained from sol–gel solutions showed good adhesion to the substrate and uniform shapes, but large shrinkage, whereas those obtained from dispersion solution had high solid content, but exhibited poor adhesion and non-uniform shapes. A fabrication method of a layer-by-layer structured pattern is also demonstrated. This type of pattern may find application in sensors, waveguides and other photonics elements. The occurrence of an undesirable residue layer, which hinders the fabrication of isolated patterns, is highlighted and a method of prevention is suggested.     

Source term evaluation for the upgraded LEU Pakistan Research Reactor-1 under severe accidents

Evaluation of source term has been carried out for the upgraded LEU PARR-I system taken as a typical material test reactor (MTR). The modeling and simulation of release of radioactivity has been carried out by developing a Matlab based computer program which uses the ORIGEN2 code for core inventory calculations. For post 180 full-power days continuous operation, various accident scenarios, with instantaneous release of radioactivity to containment, have been considered including the startup, fuel loading, and loss-of-coolant accidents. For noble gases, iodine and for aerosols, the release rate studies have been carried out for the normal, emergency and for the isolation states of containment. The values of source term as well as that of containment retention factor show rapid increase followed by an approach towards saturation values as the exhaust rate values are increased. The isotope-dependency of the containment retention factor has been studied and the results indicate strong sensitivity for ⁸⁵Kr, ¹³⁷Xe, ¹³⁸Xe and ¹³⁸Cs towards exhaust rate values.     

Study of coking and catalyst stability over CaO promoted Ni-based MCF synthesized by different methods for CH4/CO2 reforming reaction

CaO doped Ni/MCF catalysts were prepared by conventional incipient wetness impregnation and sol-gel methods for the study of methane dry reforming reaction. The fresh and used catalysts were characterized using H₂ temperature programmed reduction (H₂-TPR), X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), thermogravimetry (TG), differential scanning calorimetry (DSC) and O₂ temperature-programmed oxidation (O₂-TPO). XRD exhibited that CaO and Ni particles are dispersed on the surface of catalyst. The Ni:CaO ratio was adjusted for the improvement of pore textural properties on behalf of enhancement of metal particle dispersion for increased catalytic performance and anti-coking. The catalytic performance and stability of the catalysts for methane dry reforming reaction were studied at 700–750 °C at atmospheric pressure with GHSV of 24000 mL g^?1h^?1 having same feed ratio of CH₄:CO₂ = 1. Experimental results exhibited that catalyst prepared by a sol-gel method showed superior catalytic activity, stability and resisted carbon deposition than catalyst prepared incipient wetness impregnation method. Among all tested catalysts 9CaO 9Ni/MCF catalyst remained the best for catalytic performance and anti-coking activity due to higher metal dispersion with small metal particles, as well as the synergetic effect between CaO and Ni. During 75 h stability test over the catalyst 9CaO 9Ni/MCF the CH₄ and CO₂ conversion remained 91% and 99% respectively.     

Role and Perspectives of Inflammation and C-Reactive Protein (CRP) in Psychosis: An Economic and Widespread Tool for Assessing the Disease

Schizophrenia is a major psychotic disorder affecting nearly 23.6 million people globally and greatly impacting the cognitive and social functioning of individuals. Multiple risk factors, including genetic, environmental, and epigenetic factors have been identified. However, the exact mechanism by which some factors aid in the development of schizophrenia is still uncertain. Acute and/or long-standing inflammation has been implicated as both a cause and effect of schizophrenia. Heightened immune responses have been documented in large cohorts of individuals with schizophrenia. While not completely known, multiple hypotheses, such as disruption of the blood–brain barrier, alterations in the kynurenine/tryptophan pathway, and increased microglial activation, have been presented to correlate inflammation with schizophrenic symptoms. Measurement of C-reactive protein (CRP) is a commonly performed and inexpensive test on patients’ serum to determine levels of systemic inflammation in the body. Multiple studies have reported an elevated CRP level in different stages of schizophrenia, indicating its potential to be used as a viable biomarker in the diagnosis and monitoring of schizophrenia along with assessing treatment response to conventional and non-conventional treatment regimens. This review aims to evaluate the role of inflammation, in general, and CRP, in particular, in the pathogenesis of schizophrenia and its potential significance in diagnostic, therapeutic, and preventative approaches towards schizophrenia and psychosis.     

Genes and Longevity of Lifespan

Aging is a complex process indicated by low energy levels, declined physiological activity, stress induced loss of homeostasis leading to the risk of diseases and mortality. Recent developments in medical sciences and an increased availability of nutritional requirements has significantly increased the average human lifespan worldwide. Several environmental and physiological factors contribute to the aging process. However, about 40% human life expectancy is inherited among generations, many lifespan associated genes, genetic mechanisms and pathways have been demonstrated during last decades. In the present review, we have evaluated many human genes and their non-human orthologs established for their role in the regulation of lifespan. The study has included more than fifty genes reported in the literature for their contributions to the longevity of life. Intact genomic DNA is essential for the life activities at the level of cell, tissue, and organ. Nucleic acids are vulnerable to oxidative stress, chemotherapies, and exposure to radiations. Efficient DNA repair mechanisms are essential for the maintenance of genomic integrity, damaged DNA is not replicated and transferred to next generations rather the presence of deleterious DNA initiates signaling cascades leading to the cell cycle arrest or apoptosis. DNA modifications, DNA methylation, histone methylation, histone acetylation and DNA damage can eventually lead towards apoptosis. The importance of calorie restriction therapy in the extension of lifespan has also been discussed. The role of pathways involved in the regulation of lifespan such as DAF-16/FOXO (forkhead box protein O1), TOR and JNK pathways has also been particularized. The study provides an updated account of genetic factors associated with the extended lifespan and their interactive contributory role with cellular pathways.     

Preparation of electrospun nanofibrous polycaprolactone scaffolds using nontoxic ethylene carbonate and glacial acetic acid solvent system

In recent years, solution electrospinning has attracted the interest of researchers due to the possibility to design nanofibrous scaffolds with large surface area to volume ratios. Polycaprolactone (PCL), because of its biocompatibility and easy processability, has been widely used to develop electrospun structures for tissue engineering. However, the use of organic solvents and the poor PCL solution stability still hinder the development of the solution electrospinning process. The relatively benign glacial acetic acid (GAC) as a solvent of PCL was used to fabricate microfibrous fibers or beaded fibers. Thus, ethylene carbonate (EC) as a nontoxic assistant solvent was added to the PCL/GAC solution to successfully fabricate electrospun nanofibrous PCL scaffolds. The stability of the PCL/GAC/EC solution system was demonstrated as the viscosity, which showed no significant change during 48 h. The ultrafine PCL fiber diameter decreased as EC concentration was increased from 0 to 9 vol% and started to slightly increase when EC concentration increased beyond 9 vol%. MTT assay evidenced that MC3T3-E1 cells on the nanofibrous PCL scaffolds exhibited a better enhancement on cell proliferation. In summary, EC was added in PCL/GAC to establish a stable and low toxic solution electrospinning system, which provides promising strategy in tissue engineering field. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48387.