245 research outputs found

    Microstructure and properties of silicon alloyed compacted graphite irons (CGI)

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    The microstructure, tensile properties and hardness of 25 mm thick compacted graphite iron samples alloyed with 3,01, 3,22, 3,61, 3,97 and 4,29 wt. % Si were analyzed in this paper. It was found that Si promotes and strengthens ferrite. Metallic matrix of compacted graphite iron sample alloyed with 3,01 wt. % Si consisted of 98,1 % ferrite and 1,9 % pearlite. Fully ferritic metallic matrix was obtained in compacted graphite iron samples alloyed with 3,22, 3,61, 3,97 and 4,29 wt. % Si. Nodularity varied from 8 to 13 %. Yield strength increased from 246 to 447 N/mm2, tensile strength increased from 318 to 496 N/mm2, hardness increased from 160 to 227 HBW, and elongation decreased from 3,6 to 1,6 % with an increase in Si content from 3,01 to 4,29 wt. %. Analyzed Si alloyed compacted graphite iron samples have a very uniform hardness and higher ratio Rp02/Rp02 than conventional ferritic, ferritic-pearlitic and pearlitic compacted graphite iron grades

    Klotho pathways, myelination disorders, neurodegenerative diseases, and epigenetic drugs

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    In this review we outline a rationale for identifying neuroprotectants aimed at inducing endogenous Klotho activity and expression, which is epigenetic action, by definition. Such an approach should promote remyelination and/or stimulate myelin repair by acting on mitochondrial function, thereby heralding a life-saving path forward for patients suffering from neuroinflammatory diseases. Disorders of myelin in the nervous system damage the transmission of signals, resulting in loss of vision, motion, sensation, and other functions depending on the affected nerves, currently with no effective treatment. Klotho genes and their single-pass transmembrane Klotho proteins are powerful governors of the threads of life and death, true to the origin of their name, Fates, in Greek mythology. Among its many important functions, Klotho is an obligatory co-receptor that binds, activates, and/or potentiates critical fibroblast growth factor activity. Since the discovery of Klotho a little over two decades ago, it has become ever more apparent that when Klotho pathways go awry, oxidative stress and mitochondrial dysfunction take over, and age-related chronic disorders are likely to follow. The physiological consequences can be wide ranging, potentially wreaking havoc on the brain, eye, kidney, muscle, and more. Central nervous system disorders, neurodegenerative in nature, and especially those affecting the myelin sheath, represent worthy targets for advancing therapies that act upon Klotho pathways. Current drugs for these diseases, even therapeutics that are disease modifying rather than treating only the symptoms, leave much room for improvement. It is thus no wonder that this topic has caught the attention of biomedical researchers around the world.https://www.liebertpub.com/doi/10.1089/biores.2020.0004Published versio

    Carbohydrate Antigen 125: A Biomarker at the Crossroads of Congestion and Inflammation in Heart Failure

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    Because heart failure (HF) is more lethal than some of the common malignancies in the general population, such as prostate cancer in men and breast cancer in women, there is a need for a cost-effective prognostic biomarker in HF beyond natriuretic peptides, especially concerning congestion, the most common reason for the hospitalisation of patients with worsening of HF. Furthermore, despite diuretics being the mainstay of treatment for volume overload in HF patients, no randomised trials have shown the mortality benefits of diuretics in HF patients, and appropriate diuretic titration strategies in this population are unclear. Recently, carbohydrate antigen (CA) 125, a well-established marker of ovarian cancer, emerged as both a prognostic indicator and a guide in tailoring decongestion therapy for patients with HF. Hence, in this review the authors present the molecular background regarding the role of CA125 in HF and address valuable clinical aspects regarding the relationship of CA125 with both prognosis and therapeutic management in HF

    Pathogenic mitochondrial dysfunction and metabolic abnormalities

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    Herein we trace links between biochemical pathways, pathogenesis, and metabolic diseases to set the stage for new therapeutic advances. Cellular and acellular microorganisms including bacteria and viruses are primary pathogenic drivers that cause disease. Missing from this statement are subcellular compartments, importantly mitochondria, which can be pathogenic by themselves, also serving as key metabolic disease intermediaries. The breakdown of food molecules provides chemical energy to power cellular processes, with mitochondria as powerhouses and ATP as the principal energy carrying molecule. Most animal cell ATP is produced by mitochondrial synthase; its central role in metabolism has been known for >80 years. Metabolic disorders involving many organ systems are prevalent in all age groups. Progressive pathogenic mitochondrial dysfunction is a hallmark of genetic mitochondrial diseases, the most common phenotypic expression of inherited metabolic disorders. Confluent genetic, metabolic, and mitochondrial axes surface in diabetes, heart failure, neurodegenerative disease, and even in the ongoing coronavirus pandemic.https://doi.org/10.1016/j.bcp.2021.11480

    Epitaxial growth of Bi<sub>12</sub>GeO<sub>20</sub> thin film optical waveguides using excimer laser ablation

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    Thin-film optical waveguides of the photorefractive optical material bismuth germanium oxide (Bi12GeO20) have been epitaxially grown onto heated zirconia substrates by excimer laser ablative sputtering. The epitaxial nature and stoichiometry of the films were verified using x-ray diffraction analysis. Waveguide modes were observed for effective refractive indices in close agreement with theoretical predictions

    “Emotional Exhaustion and Perceived Corporate Social Responsibility: A Case Study of a Port Logistics Organization”

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    In an era of economic crisis, and at the shadow of major ethical scandals in organizations, Corporate Social Responsibility (CSR) strategy has emerged as a crucial element to reestablish the bond between corporations and all other stakeholders such as the local community, society and labor force. Crisis makes employees more stressful, since they work on unwarranted jobs causing them emotional exhaustion. This study aims to examine the association between employee emotional exhaustion and perceived corporate social responsibility (CSR). For this purpose, this study conducted a survey which examines if CSR (ethical, social, environmental dimensions) is negatively related to emotional exhaustion of employees on a sample of 93 employees of a port logistics management services organization. A structured questionnaire was developed in order to measure emotional exhaustion and employee perceptions about CSR activities. Building on the claim that employee perceptions of CSR activities may significantly related to emotional state, this paper examines three CSR dimensions (social, ethical and environmental) and emotional exhaustion. The results of this study indicate that environmental CSR exerts a negative significant effect on Emotional exhaustion. These finding will be of great value as they can contribute on understanding the impact of environmental CSR on emotional exhaustion with detrimental effects on employees’ productivity, job performance, and creativity. The importance of CSR environmental aspects and the relative strategies guiding CSR impact on emotional exhaustion affecting job-related outcomes are also discussed

    Nanotechnology in medicine – our experiences

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    The success of design criteria for long-circulating drug delivery systems to support membrane receptor-ligand interaction and internalization has been limited and there is a need to develop smarter approaches for efficient drug tumor targeting. In order to overcome some of the current limitations, stimulus-responsive targeting has been combined with passive and active targeting strategies. More innovative nanocarriers that hold promise to optimize targeted drug delivery are systems with the ability for transformation from the stealth long-circulating form to cell interactive form in the complex tumor environment, exposing ligands at their surface for improved ligandreceptor interaction and cell internalization. This short review will be an overview of several nanomedicines designed and characterized by our research group, and the interplay between their physicochemical characteristics and biological fate
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