Compact model of latent heat thermal storage for its integration in multi-energy systems

Nowadays, flexibility through energy storage constitutes a key feature for the optimal management of energy systems. Concerning thermal energy, Latent Heat Thermal Storage (LHTS) units are characterized by a significantly higher energy density with respect to sensible storage systems. For this reason, they represent an interesting solution where limited space is available. Nevertheless, their market development is limited by engineering issues and, most importantly, by scarce knowledge about LHTS integration in existing energy systems. This study presents a new modeling approach to quickly characterize the dynamic behavior of an LHTS unit. The thermal power released or absorbed by a LHTS module is expressed only as a function of the current and the initial state of charge. The proposed model allows simulating even partial charge and discharge processes. Results are fairly accurate when compared to a 2D finite volume model, although the computational effort is considerably lower. Summarizing, the proposed model could be used to investigate optimal LHTS control strategies at the system level. In this paper, two relevant case studies are presented: (a) the reduction of the morning thermal power peak in District Heating systems; and (b) the optimal energy supply schedule in multi-energy systems

Toward a unified pathophysiology in COVID-19 acute aortopathies

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Aortoaortic bypass pathophysiology

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Lowered Tumor Necrosis Factor Receptors, but Not Increased Insulin Sensitivity, with Infliximab

AbstractObjectives: To verify whether Infliximab could modify insulin sensitivity and TNF‐α and GLUT4 mRNA expression in muscle and adipose tissue of morbidly obese subjects. Soluble TNF receptors I and II (TNFR‐I and TNFR‐II) were also assayed.Research Methods and Procedures: Six obese subjects were investigated before and 2 weeks after a single intravenous administration of 5 mg/kg Infliximab; insulin sensitivity was evaluated by euglycemic hyperinsulinemic clamp, and TNF‐α and GLUT4 mRNA expression were assessed by reverse‐transcriptase polymerase chain reaction on muscle and adipose tissue. TNF‐α, TNFR‐I, and TNFR‐II were determined using the ELISA technique.Results: Infliximab infusion did not affect fasting plasma insulin or fasting plasma glucose levels; whole body glucose uptake did not change significantly. TNF‐α and GLUT4 mRNA did not show any significant change in muscle or adipose tissue. Serum TNF‐α was undetectable before and after treatment, whereas TNFR‐I and TNFR‐II concentrations significantly decreased (p < 0.01).Discussion: An explanation for the absence of effect of Infliximab on insulin resistance in morbidly obese subjects may be the paracrine way of action of this cytokine. Because Infliximab is predominantly distributed within the vascular compartment, its effectiveness in penetrating muscle and adipose tissue is potentially low. The significant decrease of TNFR‐I and TNFR‐II might be ascribed to a targeted effect of Infliximab on the immune system

A 3D printable adapter for solid-state fluorescence measurements: the case of an immobilized enzymatic bioreceptor for organophosphate pesticides detection

The widespread use of pesticides in the last decades and their accumulation into the environment gave rise to major environmental and human health concerns. To address this topic, the scientific community pointed out the need to develop methodologies to detect and measure the presence of pesticides in different matrices. Biosensors have been recently explored as fast, easy, and sensitive methods for direct organophosphate pesticides monitoring. Thus, the present work aimed at designing and testing a 3D printed adapter useful on different equipment, and a membrane support to immobilize the esterase-2 from Alicyclobacillus acidocaldarius (EST2) bioreceptor. The latter is labelled with the IAEDANS, a bright fluorescent probe. EST2 was selected since it shows a high specificity toward paraoxon. Our results showed good stability and replicability, with an increasing linear fluorescent intensity recorded from 15 to 150 pmol of labelled EST2. Linearity of data was also observed when using the immobilized labelled EST2 to detect increasing amounts of paraoxon, with a limit of detection (LOD) of 0.09 pmol. This LOD value reveals the high sensitivity of our membrane support when mounted on the 3D adapter, comparable to modern methods using robotic workstations. Notably, the use of an independent support significantly simplified the manipulation of the membrane during experimental procedures and enabled it to match the specificities of different systems. In sum, this work emphasizes the advantages of using 3D printed accessories adapted to respond to the newest research needs. Graphical abstract: [Figure not available: see fulltext.

A FRET Approach to Detect Paraoxon among Organophosphate Pesticides Using a Fluorescent Biosensor

The development of faster, sensitive and real-time methods for detecting organophosphate (OP) pesticides is of utmost priority in the in situ monitoring of these widespread compounds. Research on enzyme-based biosensors is increasing, and a promising candidate as a bioreceptor is the thermostable enzyme esterase-2 from Alicyclobacillus acidocaldarius (EST2), with a lipase-like Ser–His–Asp catalytic triad with a high affinity for OPs. This study aimed to evaluate the applicability of Förster resonance energy transfer (FRET) as a sensitive and reliable method to quantify OPs at environmentally relevant concentrations. For this purpose, the previously developed IAEDANS-labelled EST2-S35C mutant was used, in which tryptophan and IAEDANS fluorophores are the donor and the acceptor, respectively. Fluorometric measurements showed linearity with increased EST2-S35C concentrations. No significant interference was observed in the FRET measurements due to changes in the pH of the medium or the addition of other organic components (glucose, ascorbic acid or yeast extract). Fluorescence quenching due to the presence of paraoxon was observed at concentrations as low as 2 nM, which are considered harmful for the ecosystem. These results pave the way for further experiments encompassing more complex matrices