Case Report Primary Amyloidosis Manifesting as Cholestatic Jaundice after Laparoscopic Cholecystectomy

A 71-year-old female patient with cholelithiasis who had undergone laparoscopic cholecystectomy was admitted with obstructive jaundice (total bilirubin ∼6 mg/dL) three months later. An ERCP was performed, in which a gallstone was found, followed by a sphincterotomy and cleansing of the bile duct. Due to deterioration of jaundice (>25 mg/dL), a new, unsuccessful ERCP and stent placement was carried out. Because of ongoing cardiac failure, she underwent an echocardiogram which revealed restrictive cardiomyopathy possibly due to amyloidosis. A liver biopsy was performed, which was positive for amyloid deposits in the liver, and the diagnosis was confirmed by the detection of monoclonal IgG protein in urine. The patient's jaundice gradually deteriorated and she died one week later from hepatic insufficiency

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

On the exploitation of dynamic simulations for the design of buildings energy systems

To achieve the Paris Agreement 1.5 °C target, apart from the obligation for new buildings to be ZEBs, the existing building stock should be retrofitted as well, in order to improve their energy efficiency by using more efficient electromechanical energy systems and envelope materials, whereas RES should cover their energy needs. In this context, Energy Performance Certificates (EPCs) have been institutionalized to certify the energy behavior of buildings. Various types of buildings energy modeling tools and calculation methods have been proposed for EPCs procedures. This study focuses on the energy performance gap between dynamic and quasi steady-state simulation tools. The results from a comparative case study have shown remarkable discrepancies between dynamic and quasi-steady-state simulation processes, for the same building. Indeed, the quasi-steady-state simulation tool estimates 4.5% higher annual electricity consumption per conditioned area for the existing building and approximately 74% less energy savings for the retrofitted one, leading to an overestimation of 85% in CO2 emissions prediction. Finally, compared to the analysis with the dynamic simulation tool, an increased retrofit cost, approximately by 19.7% (and thus 3 times higher payback period), is needed according to the results of the quasi-steady-state simulation tool, in order to achieve the same Energy classification

Enhanced nZEB concept incorporating a sustainable Grid Support Scheme

The building sector in Europe represents a large amount of the total energy consumption. European Union policies urge energy management systems installation in buildings, to achieve the nZEB targets and mitigate the climate change. Except for renewable energy sources, the incorporation of energy storage units (ESUs) is of major importance for building energy management, in order to increase self-consumption levels. The present work contributes to the mass installation of ESUs in building sector, as a tool to provide flexibility in the distributed production of energy. This concept is an enhanced version of nZEBs that is able to compete in the Electricity Market, and to contribute to the reliability and flexibility of the electricity grid as an alternative to centralized ESUs investments. In this context, the present work proposes a new type of grid ancillary services for building sector and a novel Grid Support Scheme (GSS) that considers both the energy fluctuations of the available energy in the ESU as well as the energy transactions with the grid. The proposed GSS model concludes to a pricing policy relying on the Value of Lost Load (VoLL), in order that the proposed grid support investment becomes sustainable. The validation of the GSS is performed by means of Life Cycle Cost Assessment

Energy yield estimation of on-vehicle photovoltaic systems in urban environments

Greenhouse gases from the propulsion systems of road transportations constitute a significant obstacle to achieve the Paris Agreement objectives. Nowadays, the substitution of conventional internal combustion engines with electric motors, along with electrochemical storage systems are the leading efforts to reduce the use of fossil fuels in road transportations. However, their limited driving range and the long charging times are the main technical factors that hinder the development of electromobility. Thus, energy harvesters and regeneration systems are increasingly incorporated in road vehicles, in order to increase their driving range. In this context, Vehicle Integrated and Applied Photovoltaics (VIAPVs) constitute an attractive prospect. The electricity yield for VIAPVs depends strongly on the route, the shadings due to the urban environment, the applied Maximum Power Point (MPPT) algorithm and the traffic conditions. In this paper, four commonly used commercial MPPT algorithms are experimentally evaluated, regarding their ability to extract the maximum available power simulating realistic city routes. The results show notable discrepancies in the performance of the studied algorithms, between terrestrial and VIAPV applications, highlighting the impact of poor MPPT performance in terms of power generation in moving vehicles

Analysis, design and simulation of an on-chip DC/DC/AC conversion system for PV applications

Summarization: This paper presents the analysis and design procedure of a low voltage, reconfigurable, on-chip DC/DC - DC/AC power conversion system for PV applications. The whole work is carried out in the context of a novel smart PV system development, which is based on integrated PV cell inverters. Various power converter topologies are investigated in order the most appropriate for the DC/DC and DC/AC power stages to be selected. The synchronous boost DC/DC converter and the H-bridge inverter are the preferred solution, in terms of complexity, efficiency and cost. The specifications of the power conversion system are given, along with the theoretical analysis for the synchronous boost converter and H-bridge inverter operation. Moreover, the chip design process is presented, highlighting the design constraints and limitations obtained. Finally, in order the functionality of the above concept to be validated, PSpice simulations are carried out, indicating the high efficiency and low complexity of the proposed power conversion system.Παρουσιάστηκε στο: 5th Panhellenic Conference on Electronics and Telecommunication