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Abstract Background Soluble amyloid-beta oligomers (Aβo) begin to accumulate in the human brain one to two decades before a clinical diagnosis of Alzheimer’s disease (AD). The literature supports that soluble Aβo are implicated in synapse and neuronal losses in the brain regions such as the hippocampus. This region importantly contributes to explicit memory, the first type of memory affected in AD. During AD preclinical and prodromal stages, people are also experiencing wake/sleep alterations such as insomnia (e.g., difficulty initiating sleep, decreased sleep duration), excessive daytime sleepiness, and sleep schedule modifications. In addition, changes in electroencephalographic (EEG) activity during wake and sleep have been reported in AD patients and animal models. However, the specific contribution of Aβo to wake/sleep alterations is poorly understood and was investigated in the present study. Methods Chronic hippocampal injections of soluble Aβo were conducted in male rats and combined with EEG recording to determine the progressive impact of Aβ pathology specifically on wake/sleep architecture and EEG activity. Bilateral injections were conducted for 6 consecutive days, and EEG acquisition was done before, during, and after Aβo injections. Immunohistochemistry was used to assess neuron numbers in the hippocampal dentate gyrus (DG). Results Aβo injections did not affect the time spent in wakefulness, slow wave sleep (SWS), and paradoxical sleep but altered EEG activity during wake and SWS. More precisely, Aβo increased slow-wave activity (SWA; 0.5–5 Hz) and low-beta activity (16–20 Hz) during wake and decreased theta (5–9 Hz) and alpha (9–12 Hz) activities during SWS. Moreover, the theta activity/SWA ratio during wake and SWS was decreased by Aβo. These effects were significant only after 6 days of Aβo injections and were found with alterations in neuron counts in the DG. Conclusions We found multiple modifications of the wake and SWS EEG following Aβo delivery to the hippocampus. These findings expose a specific EEG signature of Aβ pathology and can serve the development of non-invasive and cost-effective markers for the early diagnosis of AD or other amyloid-related diseases.

The black fungus is a SARS-CoV-2-associated fungal co-infection. Mechanisms by which antifungal drugs act against Mucormycosis are by inhibition of enzymes implicated in ergosterol biosynthesis or cell wall formation or the drug interaction directly with ergosterol. Since it has been shown that the reduction of ergosterol biosynthesis prevents this infection, we carried out a virtual screening with molecular docking analysis and tested a dataset of 880 molecules for its effects on an enzyme involved in ergosterol biosynthesis (CYP51) and fungal infection (lipase), as well as ADMET and toxicity properties of the studied molecules. We calculated the stability of the complex’s inhibitor-enzyme throughout the time using molecular dynamics simulations. From this, initial screening indicated that 600 out of a total of 880 compounds have a good affinity towards sterol 14α-demethylase. The two compounds ZINC95486139 and ZINC33833639 were determined as safe and have good drug-likeness properties, and have binding energies of −75.07 and −83.89 kcal/mol, respectively by MMGBSA and create strong and stable interactions with the residues of the active site of the enzyme. To the best of our knowledge, ZINC95486139 and ZINC33833639 have not yet been described in the literature as anti-sterol 14α-demethylase inhibitors or evaluated for their anti-fungal activity.

Summary: This paper outlines the development of an interleaved bidirectional DC–DC converter featuring single‐phase high‐frequency isolation and employing two distinct pulse width modulations (PWMs), one for each power flow direction. The analysis of converter stages, expressions for DC voltage gains, and voltage/current stresses in continuous conduction mode are presented. The proposed converter offers several advantages, including a new modulation approach, a current ripple frequency, and voltage in two ports that are four times higher than the switching frequency. Additionally, it entails a reduction in the volume and weight of passive elements and ensures balanced current distribution between the arms. Moreover, the single‐phase transformer offers galvanic isolation between the DC bus and the battery or supercapacitor. An experimental prototype has been implemented in the laboratory to validate the mathematical and theoretical analysis for both energy flow directions under the test conditions, with a converter‐rated power of 2.5 kW, a low voltage side of 180 V, and a high voltage side of 380 V. [ABSTRACT FROM AUTHOR]

ABSTRACT This manuscript offers an in‐depth exploration of electrolysis, focusing on the various types of electrolyzers and providing a detailed analysis of their respective advantages and disadvantages. Additionally, it presents a comprehensive review of DC–DC and AC–DC converters, highlighting their essential roles in green hydrogen production and explaining their functionality and applications in detail. Furthermore, the manuscript examines the diverse power electronic systems used in green hydrogen production, underscoring the crucial importance of converters. The investigation also covers effective strategies for integrating these technologies, with the goal of optimizing the green hydrogen production process. This study aims to significantly advance knowledge in sustainable technologies, emphasizing the pivotal role of power electronics in electrolysis, fostering the generation of renewable energy, and reinforcing the commitment to a greener and more sustainable future. [ABSTRACT FROM AUTHOR]

This paper introduces a novel topology for a non‐isolated bidirectional multiphase single inductor (BMPSIC) DC–DC converter. The proposed BMPSIC requires only a single inductor, irrespective of the number of arms, and features reduced volume and weight compared to the total magnetics needed for a conventional converter with similar ratings. The proposed BMPSIC advantages include a high DC voltage gain without operating on a large duty cycle, voltage stress on the power switches equal to that at the high‐voltage port, easy implementation, and a lower cost for application at high‐power densities. Furthermore, this topology requires only one current and voltage control loop. This paper thoroughly details the steady‐state operating principles of the inductor current continuous mode. It provides theoretical and mathematical analysis, including a comparative analysis of the proposed BMPSIC against earlier DC–DC converters, highlighting the superior performance and efficiency of the BMPSIC. An 8‐kW laboratory prototype, designed as a proof of concept, has been meticulously developed and tested, showcasing the performance of the converter across a broad range of load variations. The efficiency measured for the rated load exceeded 98.2% at the low‐voltage port of 250 V and the high‐voltage port of 400 V. Additionally, the article features Video S1, which illustrates the functioning of the converter. [ABSTRACT FROM AUTHOR]

The importance of renewable energies and energy storage system forming a micro-grid and integrating it to the electrical grid is widely spread. A supervisory system plays a crucial role in controlling, managing, and planning the micro-grid. This paper demonstrates the development of a new custom supervisory system based on Internet of Things (IoT), creating an information sharing environment. The proposed supervisory system is based on open-source tools for a micro-grid, composed of a photovoltaic power plant and a storage system, employing smart devices and making non-smart devices compatible with IoT systems. The new supervisory improves the available system by incorporating new features and devices and increasing the data polling rate when necessary. A comparison between the current supervisory system and the proposed one is performed, showing that the new system is more flexible, easily modified, cost-effective, and more fault-resilient.

Primary graft dysfunction (PGD) is characterized by alveolar epithelial and vascular endothelial damage and inflammation, lung edema and hypoxemia. Up to one-third of recipients develop the most severe form of PGD (Grade 3; PGD3). Animal studies suggest that neutrophils contribute to the inflammatory process through neutrophil extracellular traps (NETs) release (NETosis). NETs are composed of DNA filaments decorated with granular proteins contributing to vascular occlusion associated with PGD. The main objective was to correlate NETosis in PGD3 (n = 9) versus non-PGD3 (n = 27) recipients in an exploratory study. Clinical data and blood samples were collected from donors and recipients pre-, intra- and postoperatively (up to 72 h). Inflammatory inducers of NETs’ release (IL-8, IL-6 and C-reactive protein [CRP]) and components (myeloperoxidase [MPO], MPO-DNA complexes and cell-free DNA [cfDNA]) were quantified by ELISA. When available, histology, immunohistochemistry and immunofluorescence techniques were performed on lung biopsies from donor grafts collected during the surgery to evaluate the presence of activated neutrophils and NETs. Lung biopsies from donor grafts collected during transplantation presented various degrees of vascular occlusion including neutrophils undergoing NETosis. Additionally, in recipients intra- and postoperatively, circulating inflammatory (IL-6, IL-8) and NETosis biomarkers (MPO-DNA, MPO, cfDNA) were up to 4-fold higher in PGD3 recipients compared to non-PGD3 (p = 0.041 to 0.001). In summary, perioperative elevation of NETosis biomarkers is associated with PGD3 following human lung transplantation and these biomarkers might serve to identify recipients at risk of PGD3 and initiate preventive therapies.

This paper presents a theoretical analysis and the experimental results of the bidirectional coupled inductor dc-dc converter for dc-bus voltage regulation and power compensation in dc-microgrid applications. In dc-microgrids, a power distribution system requires a bidirectional converter to control the power flow between dc-bus and batteries. Furthermore, the dc-bus needs to be kept stabilized within certain limits and the converter handles a large range of voltage variation in the accumulators. The proposed topology is also relatively feasible for low-input-voltage applications for interfacing energy storage elements, such as batteries, ultracapacitors with the high voltage dc-bus in electric vehicles. The converter allows greater voltage gain compared to classic non-isolated topologies and can better deal with the wide range of voltage variation imposed by the source/load. The operation principles, the DC voltage gain, the design of the filters, the voltage/current stresses and a comparison are discussed. The experimental results confirmed and validated the theoretical study as well as the converter performance so that the measurements performed obtained from a 600 W laboratory prototype.

Este artigo apresenta uma nova topologia de conversor CC–CC bidirecional Push-Pull / Flyback que, em ambos os sentidos de operação, são estudados detalhadamente, incluindo a análise teórica e matemática, o ganho estático nos três modos de condução que são modo contínuo, descontínuo e crítico, além de resultados experimentais. O conversor proposto é adequado para o barramento de corrente contínua (CC) em micro-redes onde são aplicados acumuladores de energia e fontes em CC do tipo células de combustível, gerador fotovoltaico e turbina eólica. Permite fluxo bidirecional de energia, elevado ganho de tensão e possibilita a integração desses sistemas a baterias e ultracapacitores que apresentam características de baixa tensão de saída e exigem correntes elevadas com baixa ondulação. A viabilidade deste conversor com isolação galvânica é demonstrada pelos resultados obtidos por meio de um protótipo com potência nominal no sentido direto de 4 kW e rendimento acima de 90,1 %, e potência de 1,3 kW com rendimento de 84,3 % no sentido inverso do fluxo de potência.

In the rat, oxytocin (OT) produces dose-dependent diuretic and natriuretic responses. Post-translational enzymatic conversion of the OT biosynthetic precursor forms both mature and C-terminally extended peptides. The plasma concentrations of these C-terminally extended peptides (OT-G; OT-GK and OT-GKR) are elevated in newborns and pregnant rats. Intravenous injection of OT-GKR to rats inhibits diuresis, whereas injection of amidated OT stimulates diuresis. Since OT and OT-GKR show different effects on the urine flow, we investigated whether OT-GKR modulates renal action by inhibition of the arginine-vasopressin (AVP) receptor V2 (V2R), the receptor involved in renal water reabsorption. Experiments were carried out in the 8-week-old Wistar rats receiving intravenous (iv) injections of vehicle, OT, OT-GKR or OT+OT-GKR combination. OT (10 μmol/kg) increased urine outflow by 40% (P

Este artigo apresenta um conversor CC-CC trifásico abaixador e elevador de tensão com isolamento em alta frequência e alimentado em corrente que opera em toda a faixa de razão cíclica. O conversor que o originou apresenta uma região de operação proibida quando a razão cíclica é menor que 1/3 e neste estudo esta restrição é solucionada. Portanto, com a operação nesta região, funções como partida suave e pré-carga do capacitor de saída são incorporadas para evitar elevados esforços de tensão e corrente no circuito. As principais características do conversor proposto são: frequência das ondulações da tensão de saída e da corrente de entrada é três vezes maior que a frequência de comutação em todas as regiões de operação; reduzida ondulação de corrente na fonte; isolamento galvânico em alta frequência; permite pré carga e partida suave para razão cíclica inferior a 1/3; cancelamento da ondulação de corrente na fonte de alimentação quando a razão cíclica é 1/3 ou 2/3. O conversor tem como principais aplicações, aquelas alimentadas por célula a combustível, baterias e painéis fotovoltaicos. O protótipo experimental implementado opera com frequência de comutação de 20 kHz, tensão de entrada de 70 V à 120 V, tensão de saída de 52 V à 625 V e potência de saída de 650 W até 4 kW