Loss Mechanisms Research Articles

A Potential Role for the Amyloid Precursor Protein in the Regulation of Interferon Signaling, Cholesterol Homeostasis, and Tau Phosphorylation in Niemann-Pick Disease Type C.

Niemann-Pick disease type C (NPC) is a rare and fatal neurological disorder caused by mutations in Npc1 or Npc2, with Npc1 accounting for 95% of cases. These mutations result in the functional loss of their respective proteins, causing cellular abnormalities characterized by disrupted lipid dysregulation, calcium dysfunction, elevated damage associated molecular patterns (DAMPs), and a pro-inflammatory environment. This cellular pathology ultimately triggers neurodegeneration, with the cerebellum being the earliest and most affected region. We have recently shown atypical activation of interferon signaling in the presymptomatic Npc1-/- mouse cerebellum and, to a lesser extent, in the cerebral cortex. In addition, we reported that the Amyloid Precursor Protein (APP) is an NPC disease modifier. Loss of APP function leads to widespread neurodegeneration in the NPC brain, including exacerbated interferon signaling in the cerebellum. To better understand the role of APP as a disease modifier throughout the NPC brain, here we carried out a transcriptomic analysis of the cerebral cortex and cerebellum from 3-week-old Npc1-/- mice as well as age-matched controls in the presence and absence of APP. We report differential effects of APP loss of function in the cerebral cortex and cerebellum, including cholesterol and tau dysregulation, in both brain regions. Our findings demonstrate a novel link between APP loss and early pathogenic mechanisms in NPC.

Experimental and numerical investigation on middle passage gap leakage with different mass flow rate and injection angle on turbine endwall

Regarding the actual installation feature of the blades and disk using tenon and mortise, the middle passage gap exists between the adjacent blades and the leakage flows out of the gap, cooling the endwall. To explore the balance between the aerodynamic and cooling performance on blade endwall in turbine cascade, this paper investigated the effect of middle passage gap leakage under various mass flow rate and injection angle configurations. Film cooling effectiveness measurement was performed with pressure-sensitive paint technique in a five-passages linear cascade. The mass flow ratio of middle passage gap leakage ranged from 0.5 % to 1.5 % with the injection angle (αm) ranging from −20° to 20°. A combined approach utilizing numerical simulations to elucidate detailed aerodynamic loss mechanisms and experimental results of middle passage gap leakage was employed. The results show that increasing the mass flow rate of middle passage gap leakage does not suppress mainstream intrusion phenomenon. Cases with injection angle generally show improved cooling performance compared to the non-injection case (αm = 0°). The least improvements are 19 % and 27.9 % for mass flow rates of 0.5 % and 1.0 %, respectively. The case with an injection angle of 20° demonstrates the best comprehensive performance, achieving higher area-averaged cooling effectiveness and lower aerodynamic loss (1.2 % and 18.9 % decrease for mass flow rates of 0.5 % and 1.0 %).

Enhanced electromagnetic wave absorption of La3+–Zr4+ cosubstituted M−type barium hexaferrite

The development and breakthrough of electronic information technology have led to a profound focus on exploring new millimeter-wave absorbing materials. Herein, La–Zr ions co-substituted barium ferrite BaxLa1−xZrxFe12−xO19 (BLZFO) was prepared using a sol–gel method. BaFe12O19 possesses a dual loss mechanism (electrical/magnetic) and exhibits a natural resonance frequency of ∼ 45 GHz, making it effective for millimeter-wave absorption. The presence of La–Zr ions enhances the electromagnetic parameters of the material, improving its attenuation ability and optimizing impedance matching. Consequently, a wide, effective absorption frequency band and a minimal matching thickness are achieved. Specifically, within the 26.5–40 GHz range (Ka-band), BLZFO (x = 0.4) demonstrates an effective absorption bandwidth of 12.15 GHz, an optimal reflection loss of − 21.17 dB, and a corresponding matching thickness of 0.6 mm. This material not only exhibits strong reflection loss but also meets the requirements of an effective absorption frequency bandwidth and a small matching thickness, underscoring its profound importance for millimeter-wave absorption material research.

Improving the efficiency and stability of betavoltaic batteries based on understanding efficiency fluctuations and gaps with theoretical limits

Wide-bandgap semiconductors are regarded as preferred materials for preparing semiconductor conversion devices in betavoltaic batteries due to their high theoretical conversion efficiency (ηc). However, there are a few comprehensive analytical studies on why the experimental values of ηc are generally much lower than the theoretical limit of ηc (ηc-limit) and how to improve ηc and its stability. In this work, combined with the energy deposition distributions of Ti3H2, 63Ni, and 147Pm2O3 radioactive sources in SiC obtained from Monte Carlo simulations, a multi-physical mechanism, multi-parameter coupling numerical model was established. This model can comprehensively analyze the output characteristics of betavoltaic batteries under the influence of actual device structural and material parameter changes. Our results show that changes in structural and material parameters cause significant variations in the collection efficiency (Q) of the radiation-generated electron–hole pair (RG-EHP). Considering structural parameters are easy to control, instabilities in actual SiC material parameters, which include electron diffusion length (Ln), hole diffusion length (Lp), and surface recombination velocity (S), are the main reason that ηc fluctuates significantly and is generally far lower than ηc-limit. Due to differences in the distribution of RG-EHP produced by different radioactive sources in SiC, the dominant parameters causing ηc fluctuations differ. By analyzing differences in recombination loss mechanisms under different radioactive sources, the device structures were designed in a targeted manner to make ηc closer to ηc-limit. Meanwhile, when the SiC material quality fluctuates, the stability of ηc increases by 58.5%, 35.3%, and 48.2% under Ti3H2, 63Ni, and 147Pm2O3, respectively.

Corrosion kinetics and mechanisms of 15–15Ti steel in flowing liquid lead-bismuth eutectic at 500°C

The application of Liquid Lead-Bismuth Eutectic (LBE) as a coolant in Lead-cooled Fast Reactors (LFRs) presents significant challenges due to its corrosive nature, especially at elevated temperatures. This study investigates the corrosion kinetics and mechanisms of 15–15Ti stainless steel in flowing LBE at 500 °C with oxygen concentrations ranging from 1 to 3 × 10−6 wt% and a flow rate of 1 m s-1. The research highlights the formation and growth of the Fe-Cr spinel oxide layer, which follows a parabolic rate law indicative of a diffusion-controlled process, crucial for long-term material stability predictions. Despite the initial effectiveness of the Fe-Cr spinel layer in mitigating corrosion, its integrity is compromised over time due to spallation and dissolution, allowing penetration of LBE elements and selective dissolution of Fe, Ni, and Cr. The study reveals a complex interplay between direct dissolution of steel components and spallation of the oxide layer, providing critical insights into material loss mechanisms and the degradation of structural materials in LBE-cooled reactors.

Alpha particle loss measurements and analysis in JET DT plasmas

Burning reactor plasmas will be self-heated by fusion born alpha particles from deuterium-tritium reactions. Consequently, a thorough understanding of the confinement and transport of DT-born alpha particles is necessary to maintain the plasma self-heating. Measurements of fast ion losses provide a direct means to monitor alpha particle confinement. JET’s 2021–2022 second experimental DT-campaign offers burning plasma scenarios with advanced fast ion loss diagnostics for the first time in nearly 25 years. Coherent and non-coherent alpha losses were observed due to a variety of low frequency MHD activity. This manuscript will present the loss mechanisms, spatial and pitch dependencies, scalings with plasma parameters, correlations with wall impurities, and magnitude of DT-alpha born losses.

TrajPredRNN+: A new approach for precipitation nowcasting with weather radar echo images based on deep learning

：Short-term rainfall prediction is a crucial and practical research area, with the accuracy of rainfall prediction, particularly for heavy rainfall, significantly impacting people's lives, property, and even their safety. Existing models, such as ConvLSTM, TrajGRU, and PredRNN, exhibit limitations in capturing fine-grained appearances due to insufficient memory units or addressing positional misalignment issues, thereby compromising the accuracy of model predictions. In this study, we propose trajPredRNN+, an innovative approach that integrates the trajectory segmentation model and the PredRNN deep learning model to address both limitations in nowcasting precipitation using weather radar echo images. By incorporating attention mechanisms, the model demonstrates an enhanced focus on short-term and imminent heavy rainfall events. To ensure improved stability during training, a residual network is introduced. Lastly, a more rational and effective training loss function is proposed, encompassing weight mechanism, SSIM index, and GAN loss. To validate the proposed model, we conducted a comparative experiment and an ablation experiment using the radar echo map dataset obtained from the Shenzhen Meteorological Bureau. The results of these experiments demonstrate that our model has achieved significant improvements across multiple key performance indicators.

Simulation Studies of Interfacial Kinetics of Dye-Sensitized Solar Cells Photoanodes in Scanning Electrochemical Microscopy

Approach curves in the feedback mode of scanning electrochemical microscopy (SECM) were simulated for photoanodes in dye-sensitized solar cells by finite element simulation using COMSOL Multiphysics and compared to experimental data for the sample set with varying the photoanode film thickness (ZnO, cobalt mediator, organic dye). This reveals quantitatively the effect of the mass transport limitation of the mediator diffusion and organic dye regeneration kinetics in the mesoporous photoanode. The simulation of the mesoporous material was made with a pseudo-homogeneous approach in two space dimensions.The simulation allows to extract the maximum information content from the experimental data. The light adsorption was treated as exponential decay of intensity within the photoanode (Lambert-Beer law), electron injection in the conduction band of ZnO photoanode and loss mechanism was explicitly considered. The light illumination is homogeneous over the entire simulation domain of 1 mm in diameter. Just like in the experiment, the built geometry used for the simulation has a conducting blocking layer (0.6 µm in thickness) to prevent the recombination of electrons with the back contact. The porous dye-sensitized layer has a porosity of 50 - 60% and a thickness of 1- 10 µm. The inner surface holds the dye for absorbing light. The mediator diffuses in the pore of the photoanode (internal solution) and in the bulk of the electrolyte (external diffusion). The transparent conducting glass makes the boundary of the simulation domain. The electrolyte-platinum contact is not modelled. The selected boundary conditions are equivalent to the short-circuit operation of the cell.Interestingly, the simulation suggests that built meshes which had earlier been used for porous electrode simulation could not adequately describe the electron concentration profile for thinner electrodes despite providing a correct ME electrode current for limiting cases. The mesh convergence analysis studies were made to optimize the mesh to reduce computation time and memory size. The electrons in the conduction band were quantitatively determined because transport in the semiconducting photoanode is primarily driven by a thermally activated trapping-untrapping mechanism that can be described by transport equations similar to Fick's laws.The unknown parameters (dye absorption coefficient and recombination rate constant) were adjusted to ensure various light intensities in the simulation correspond to the experiment. An accurate description of the electrons within the semiconductor is critical for explaining the time-dependent behavior of the dye-sensitized photoanode in SECM approach curves. After obtaining agreement with experimental approach curves under steady-state conditions, the same parameters are used to study the current transient obtained under intermittent illumination.

Understanding Phosphoric Acid Dynamics in High-Temperature Pemfcs: Mechanisms and Durability of PA-PBI and Ion-Pair-Based Systems.

High-Temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) can operate at > 100 oC under anhydrous conditions, providing benefits such as system simplification and superior contaminant tolerance. Most researches on HT-PEMFC have focused on PA-PBI-based system since 1995, however the durability of this system is still on controversial. Some insisted the stable operation of PA-PBI HT-PEMFC, which showed the stability under mild conditions such as low current density about 0.2 A cm-2, while others pointed out the instability specifically under accelerated stress conditions with higher current densities above 0.6 A cm-2, lower ( < 140 oC) or higher ( > 180 oC) operating temperatures, or dynamic protocols like start-up/shut-down cycles, etc.This limited durability of PA-PBI HT-PEMFC is known to be related to acid loss from the membrane-electrode-assemblies (MEAs). Several mechanisms were proposed to explain the linear and nonlinear acid loss behaviors. PA evaporation and steam-distillation are known to explain the constant PA loss. Despite the extensive efforts on mechanisms and acid loss mitigation strategies, current PA-PBI systems still struggle against the limited durability due to PA loss. To improve the durability of HT-PEMFC, a novel system was introduced based on the quaternary ammonium-biphosphate ion-pair coordinated PEM [1]. Due to a stronger interaction in the ion-pair PEMs, the durability was also improved by alleviating the PA loss during PEMFC operation. Nonetheless, the acid retention mechanism of this novel system is not explored yet.Here, we investigate the mechanisms of PA loss and PA retention within electrodes of both PA-PBI-based and ion-pair-based HT-PEMFC systems. Through PA energetics studies and experimental investigations under controlled stress conditions, we elucidate distinct PA loss/retention mechanisms in these systems, leading to different durability behaviors. Our findings offer insights for enhancing the durability of both HT-PEMFC systems [2].[1] Lim, K. H.; Lee, A. S.; Atanasov, V.; Kerres, J.; Park, E. J.; Adhikari, S.; Maurya, S.; Manriquez, L. D.; Jung, J.; Fujimoto, C.; Matanovic, I.; Jankovic, J.; Hu, Z.; Jia, H.; Kim, Y. S. Protonated phosphonic acid electrodes for high power heavy-duty vehicle fuel cells, Nature Energy, 7, 248 (2022).[2] Lim, K. H.; Matanovic, I.; Maurya, S.; Kim, Y.; Castro, E. S.; Jang, J-H.; Park, H.; Kim, Y. S. High temperature polymer electrolyte membrane fuel cells with high phosphoric acid retention, ACS Energy Letters, 8, 529 (2023).

Long Time Dynamics for Platinum Surface Area Loss in PEM Fuel Cells

Proton exchange membrane (PEM) fuel cells may emerge as a dominant clean energy source for heavy duty transport vehicles. Amongst other considerations, the lifetime performance of the fuel cell cathode catalyst layer is a key component of their future viability and a focus in the development of many proposed membrane electrode assemblies (MEAs). Typical targets of the lifetime of a PEMFC stack are on the order of thousands of hours of operation. However, running degradation tests spanning those long timescales is often impractical; and consequently, extensive work has been done developing and implementing accelerated stress tests (AST's) in order to screen proposed cathode catalyst materials for fuel cells.Much value is obtained by accurate and robust lifetime prediction models which are able bridge the gap between degradation from AST's in differential cells, and degradation of the catalyst layer in a fuel cell stack under realistic operating conditions. In other words, by parameterizing a model on short-time, subscale ASTs and extrapolating to a stack after tens of thousands of hours of operation. Commonly in such models, the electrochemically active surface area (ECSA) of platinum is used as the primary state-of-health parameter and predicted using either data-driven models or physics-based models. On one hand, data-driven models may be well suited to utilize large sets of stack data, but offer weaker extrapolation potential, conversely fitting physics-based models on global measurements of stack data is rarely a well-conditioned inverse problem.In this talk we present a scaling law on the long-time behavior of the ECSA obtained from analysis of governing physics equations from the literature. It is assumed that the primary loss mechanism is the coarsening of platinum particles, and the chief technique used is the method of averaging, which allows for the separation of two timescales: the short timescale of platinum oxide formation and dissolution, and the longer timescale over which the particle size distribution changes and a performance loss can be detected. The physics-derived asymptote for the ECSA evolution is then applied to several experiments and found to be in good agreement, allowing for a simple, streamlined lifetime prediction method for PEM fuel cells.

(Invited) Electrode Transport Resistance Analysis in Proton Exchange Membrane Water Electrolyzers

Decarbonizing sectors that are challenging and economically demanding to electrify, such as heavy-duty ground transportation, aviation, and industries like ammonia, steel, petroleum refining, synthetic fuels, and cement production, is crucial in addressing climate change and environmental pollution. The key strategy for reducing the reliance of these sectors on fossil fuels and cutting emissions involves utilizing hydrogen with low carbon intensity. Proton exchange membrane water electrolyzers (PEMWEs) play a vital role in this transition due to their high efficiency, rapid response time, and capability to electrochemically compress hydrogen. However, despite making encouraging progress, significant improvements in catalyst activity and utilization are necessary to lower loadings to levels that meet ambitious cost targets.One critical aspect of enhancing catalyst performance for achieving high currents at efficient low voltages is minimizing overpotential losses. These losses result from electron, proton, and water transport to the oxygen evolution catalysts. Additionally, there are secondary current-induced loss mechanisms, including membrane and electrode dry-out and ionic contaminant polarization.In this presentation, we will delve into the relevant transport mechanisms and the fundamental limits of reducing these overpotentials through modeling. We have evaluated the transport properties of electrodes that are challenging to directly probe due to their micrometer and sub-micrometer length scales using ultra-high-resolution three-dimensional imaging with X-ray computed tomography (nano-CT) and plasma-focused ion beam cross-sectioning with scanning electron microscopy (pFIB-SEM) for image-based simulations. Subsequently, we will briefly review existing methods for experimentally diagnosing transport limitations, as well as highlight new methods currently under development in our laboratory. These new diagnostics include a galvanostatic intermittent titration technique (GITT) for electrolyzers and a limiting-current diagnostic for PEMWEs. The presentation will conclude by highlighting fresh insights into the significance of two-phase transport, electrode and membrane dry-out, all enabled by these diagnostics and modeling.

Modelling Anodic H2O2 Accumulation in Alkaline Water Electrolysis with Experimental Validation

Hydrogen peroxide (H2O2) is a high value commodity chemical used as a green oxidant in industries such as paper milling and textile bleaching, and is currently produced by the anthraquinone oxidation process. The anodic co-production of H2O2 during alkaline water electrolysis has gained interest as a sustainable alternative for anthraquinone oxidation. However, electrochemical H2O2 production is often studied with idealized laboratory setups to determine the H2O2 formation kinetics. In this work, we perform the reaction using a flow cell with separately recirculating anolyte and catholyte. We then fit the H2O2 accumulation data to an analytical model that we derive based on mole balances that accounts for anodic generation, anodic oxidation, and bulk disproportionation of H2O2, as well as anolyte reservoir volume and anode chamber volume. We performed experiments to derive values for maximum H2O2 production at 300 mA cm-2, with values of 0.540 mmol s-1 for anodic generation of H2O2 (FEH2O2 = 58%) and 0.416 min-1 for anodic oxidation of H2O2, with a bulk disproportionation rate constant of 1.85 × 10−3 min-1. We successfully applied our model to two sources in literature to derive values for their systems as well. In all cases, the contribution of anodic oxidation of H2O2 was found to be the larger loss mechanism in comparison to bulk disproportionation. Figure 1

Multimodal X-Ray Measurements for Sulfur and Sulfide Related Electrochemical Energy Storage

Sulfur and sulfide are very promising candidates for electrochemical energy storage in electric vehicles and grid-scale storage due to their high theoretical capacity, low cost, and abundance. Although tremendous efforts have been devoted to sulfur and sulfide related batteries in recent years, they are still facing several challenges that need to be addressed before they can be widely adopted. Challenges including polysulfide shuttling effect in metal-sulfur batteries and electrochemical/interphase stabilities in sulfide solid-state electrolytes hindered their practical applications. Various techniques and strategies have been developed to address the above-mentioned challenges. However, revealing a next-level understanding of sulfur species interactions and speciation, using multimodal X-ray measurements to study the interaction temporally and spatially is still lacking. Here, we employed multimodal X-ray measurements including in situ sulfur K-edgeX-ray absorption spectroscopy, X-ray diffraction, and transmission X-ray microscopy to reveal electronic structure, crystal structure, morphology of sulfur species during battery cycling. Specifically, using operando sulfur K-edge X-ray absorption and X-ray diffraction, we obtained real-time and chemical information of sulfur species occurring at the sulfur cathode during lithium-sulfur battery operation. In the case of sulfide solid-state electrolytes, we explored the capacity loss mechanism in LiNi0.8Mn0.1Co0.1O2 cathodes when using argyrodite Li6PS5Cl sulfide solid electrolytes. Nickel K-edge X-ray absorption spectroscopy and transmission X-ray microscopy showed the cracking formation and heterogeneity in oxidation states for LiNi0.8Mn0.1Co0.1O2 cathodes using Li6PS5Cl solid-state electrolytes. In summary, we elucidated the dynamic changes in sulfur and provide insights on designing next-generation sulfur and sulfide related batteries.

Materials Integration and Catalyst Interfaces in Anion Exchange Membrane, Low Temperature Electrolysis

Hydrogen has unique advantages as an energy carrier due to its high energy density and abilities in long-term storage and to convert between chemical bonds and electricity. [1] Although hydrogen currently has a small role in energy pathways, decreasing electricity prices can allow for significant growth. Anion-exchange-membrane water electrolysis (AEMWE) holds promise for reaching reduced hydrogen production cost targets, particularly from a materials perspective, and is the primary technology pathway being studied under Low Temperature Electrolysis in the HydroGEN Energy Materials Network (EMN). In AEMWE, it has been critical to explore the impact of materials and their integration on performance and durability, thereby demonstrating and enhancing use opportunities. [2] While platinum group (PGM) -free components, including catalysts and transport layer/separator coatings are readily available that can achieve high performance at a reduced cost, individual properties and their interactions create integration challenges.[3] Specifically in performance, the inclusion of ionomer and pore structures can be more complicated than for acidic systems and the use of PGM-free materials can add difficulties in electronic and ionic transport. While AEMWE can become extremely durable when targeted for low-cost applications, additional loss sources including ionomer oxidation, materials passivation (catalyst, transport layer, separator) further complicates identifying and separating irreversible loss mechanisms, and in developing accelerated stress tests. This presentation includes an overview of efforts in AEMWE and focuses on materials choices, catalyst-ionomer-transport layer interactions, and the variety of integration strategies being employed in the HydroGEN EMN.

Exploring Low Temperature Proton Exchange Membrane Water Electrolysis Anode Catalyst Degradation Under Cathode Backpressure Conditions

Hydrogen is expected to play an important role in the decarbonization of the future energy landscape by integrating renewable, nuclear, and fossil fuels and using excess power from the grid to produce H2 that can then be stored and used for a variety of applications ranging from ammonia and steel production, stationary power, buildings, and transportation.1 In order to achieve low-cost hydrogen production that is competitive with steam methane reformation (SMR), it is necessary to decrease the capital cost and this can be done by leveraging variable renewable energy (VRE) as an electricity feedstock for LTE.2 However, cost, and durability are still current challenges in state-of-the art water electrolysis systems. More research is needed to better understand the effects of dynamic operation on electrolyzer degradation. Understanding the degradation mechanisms governing intermittent electrolysis operation can enable future improvements related to component design and system operation.In recent years, electrolyzer anode degradation has been investigated during continual intermittent operation at the single cell level. Square-wave potential cycling demonstrated higher anode degradation compared to the triangle-wave cycling over the same 525 hour test (21.9 d).3 Electrolyzers operating at differential pressures and producing electrochemically compressed hydrogen could decrease the hydrogen production cost by eliminating the need for equipment related to mechanical compression.4 This work investigates the dynamics of low-temperature proton exchange membrane (PEM) electrolyzers, with a specific focus on anode catalyst layer degradation from redox transition when subjected to hydrogen crossover from cathode backpressure conditions. While cathode backpressure and operation requirements are well understood from an industry perspective, its impact on degradation mechanisms and loss rates has been relatively underexplored when low-temperature electrolysis is focused on cost reduction and variable load.In this study, hydrogen cross-over rates were varied by cathode backpressure conditions (ambient to 30 Bar) and were compared to elucidate the impact hydrogen has on anode catalyst layer degradation. The durability test duration varied from 168 – 500+ hrs. Hydrogen cross-over rates were found to correlate to cell potential during operational shutdowns and loss rates during load cycling. Electrochemical impedance spectroscopy further demonstrates higher degrees of kinetic loss and the immergence of additional loss mechanisms. The findings presented in this research contribute to the fundamental understanding of low-temperature PEM electrolysis dynamics under cathode backpressure conditions. The implications of this research offer practical insights for the design and operation of efficient and durable electrolysis systems crucial for the advancement of sustainable hydrogen production technologies.(1) H2@Scale. Hydrogen and Fuel Cell Technologies Office. https://www.energy.gov/eere/fuelcells/h2scale.(2) Mark, R.; Jadun, P.; Gilroy, N.; Connelly, E.; Boardman, R.; Simon, A. J.; Elgowainy, A.; Zuboy, J. The Technical and Economic Potential of the H2@Scale Concept within the United States; NREL/TP-6A20-77610; National Renewable Energy Laboratory: Golden, CO, 2020.(3) Alia, S. M.; Reeves, K. S.; Yu, H.; Park, J.; Kariuki, N.; Kropf, A. J.; Myers, D. J.; Cullen, D. A. Electrolyzer Performance Loss from Accelerated Stress Tests and Corresponding Changes to Catalyst Layers and Interfaces. Journal of The Electrochemical Society 2022, 169 (5), 054517. https://doi.org/10.1149/1945-7111/ac697e.(4) Ragnhild Hancke, Thomas Holm, and Øystein Ulleberg, “The Case for High-Pressure PEM Water Electrolysis,” Energy Conversion and Management 261 (2022): 115642, https://doi.org/10.1016/j.enconman.2022.115642. Figure 1

Type 2 diabetes: a sacrifice program handling energy surplus

Abstract Type 2 diabetes mellitus (T2DM) is closely associated with obesity, while interactions between the two diseases remain to be fully elucidated. To this point, we offer this perspective to introduce a set of new insights into the interpretation of T2DM spanning the etiology, pathogenesis, and treatment approaches. These include a definition of T2DM as an energy surplus-induced diabetes characterized by the gradual decline of β cell insulin secretion function, which ultimately aims to prevent the onset of severe obesity through mechanisms of weight loss. The body employs three adaptive strategies in response to energy surplus: the first one is adipose tissue expansion to store the energy for weight gain under normal weight conditions; the second one is insulin resistance to slow down adipose tissue expansion and weight gain under overweight conditions; and the third one is the onset of T2DM following β cell failure to reverse the weight gain in obese conditions. The primary signaling molecules driving the compensatory responses are adenosine derivatives, such as adenosine triphosphate (ATP), acetyl coenzyme A (acetyl-CoA), and reduced nicotinamide adenine dinucleotide (NADH). These molecules exert their effects through allosteric, post-translational, and transcriptional regulation of metabolic pathways. The insights suggest that insulin resistance and T2DM are protective mechanisms in the defense against excessive adiposity to avert severe obesity. The perspective provides a unified framework explaining the interactions between the two diseases and opens new avenues in the study of T2DM.

Isolation of donor gamma globulin obtained from multiparous women and its effects upon expression of HLA-G and HLA-DR molecules on lymphocytes from mothers of children with septal congenital heart defects

A common pathogenetic mechanism of reproductive losses and congenital heart disease (CHD) is associated with immune inflammation in the “mother-embryo” system which affects differentiation and proliferation of cardiovascular progenitor cells. It is hypothesized that this link may be blocked by regulatory auto- and alloimmune antibodies to HLA-G and HLA-DR molecules. Moreover, these antibodies may be present at sufficient amounts in donor immunoglobulins, especially those obtained from the blood of multiparous women. Based on this suggestion, the aim of our study was to obtain enriched gamma globulin fraction from the blood of multiparous women and evaluate its functional effects towards HLA-DR and HLA-G molecules. Isolation of the gammaglobulin fraction (GGF) from the blood plasma of multiparous women was performed using affinity chromatography in several sessions. Purity grade of the resulting protein was analyzed by immunoelectrophoresis, electrophoretic separation of the protein fraction of blood serum and electrophoresis in 4.12% polyacrylamide gel with the addition of SDS (PAGE electrophoresis). PAAG electrophoresis showed that this GGF did not differ from commercial therapeutic intravenous immunoglobulin (IVIG). Assessment of the functional activity of GGF upon HLA-DR and HLA-G molecules was performed in the main group of women and their children with congenital heart disease (n = 38), and control group of women who gave birth to conditionally healthy children (n = 21). To determine the specificity of GGF with respect to HLA-G, HLA-DR molecules, as well as to compare its effect with autologous and allogeneic sera and IVIG, we developed an immunological testing protocol using flow cytometry. The protocol was arranged on the basis of the methodology of “cross-match” approach and Russian patent “Method for determining antibodies to HLA-G”. It was found that the blocking activity of female serum towards autologous (intrinsic) and allogeneic (embryo/fetus/child) HLA-G and HLA-DR molecules may determine the protective effect on development of congenital heart defects in the next generation. Donor human immunoglobulin showed a similar blocking effects to these molecules, possibly due to the presence of alloimmune antibodies to HLA classes I and II. The gammaglobulin fraction obtained from the donor blood of multiparous women has a more pronounced blocking effect on the HLA-G and HLA-DR expression. Hence, this immunobiological preparation can be considered a prototype of therapeutic and prophylactic agent blocking the genesis of congenital heart defects.

Hierarchical Significance of Environment Impact Factor on the Sand Erosion Performance of Lightweight Alloys.

This paper addresses the challenge of ranking the factors that affect the erosion resistance of lightweight alloys, with a specific focus on aluminum alloys. A three-factor, four-level orthogonal experimental design was employed to examine the influence of various sand particle sizes, erosion speeds, and sand concentrations on the abrasion qualities of these alloys. Parameters such as mass loss, depth, residual stresses, and failure mechanisms were assessed to determine erosion performance. Analysis of variance (ANOVA) and regression analysis of the three key factors were performed. Our findings resulted in an erosion rate formula: erosion rate = 0.679 sand particle size +0.067 sand concentration -0.002 erosion velocity +0.285. Our findings indicate that particle size is the most significant factor affecting erosion rate, with sand concentration and erosion velocity being secondary factors. The failure mechanism reveals that larger sand particles tend to produce deeper slides, and higher sand concentrations result in an increased number of slides. A lower concentration leads to the appearance of erosion pits. And the test conditions of high concentration and low velocity lead to more serious brittle fractures of the substrate, often accompanied by the appearance of cracks.

Temperature-Induced Nanoarchitectonics of Monolayer Self-Assembly of Heterocoronene-Based Discotic Liquid Crystals.

Enhancing molecular self-assembly at the monolayer level offers significant potential for various applications. For monolayers made of π-conjugated discotic liquid crystal (DLC) molecule nanowires, achieving precise separation and alignment of these nanowires has been a long-standing challenge. This research explores an approach using the manipulation of subphase temperature and surface pressure within a Langmuir trough to control molecular nanowire separation. We observe notable temperature-dependent behavior: as the temperature increases from 5 to 30 °C, the monolayer collapse pressure rises steadily. In contrast, temperatures from 35 to 50 °C exhibit an initial small plateau with a nonzero slope that becomes more distinct with rising temperature. Our study of Langmuir-Blodgett (LB) films provides crucial insights into the monolayer's structure. At lower temperatures, the LB films show coalesced molecular nanowires, whereas at higher temperatures, the DLC nanowires separate and form an interconnected network. Remarkably, upon compression, this network transforms into a compact, highly uniform monolayer. To explain these temperature-dependent behaviors, we examine the area relaxation curves, which indicate a two-step molecular loss mechanism involving desorption and monolayer collapse due to the nucleation and growth of critical nuclei. This extensive study offers valuable insights into the dynamic interaction of the temperature, surface pressure, and molecular assembly, enhancing our understanding of the fundamental processes in monolayer self-assembly.

Activating Excellent Electromagnetic Wave Absorption of Micromorphology-Optimized Cu/C Nanocomposite Fibers via a Metal-Organic Framework Template-Assisted Strategy.

Morphological engineering is crucial for conceiving high-efficiency electromagnetic wave (EMW) absorption materials. However, for carbon fiber-based composites, the management of micromorphology is significantly astricted by complex fabrication. It remains highly challenging to clarify the micromorphological influences on the EMW loss mechanism of carbon fiber-based absorption materials. In this work, micromorphology-optimized Cu/C nanocomposite fibers are prepared by virtue of a metal-organic framework (MOF) template-assisted strategy. Through skillfully grafting the morphology-regulation capacity of MOFs onto composite fibers, the Oswald maturation and particle distribution issues of Cu nanoparticles are settled, and the efficient electron transport pathways are established by the bead-like structure of the fiber matrix. Compared to prepared conventional Cu/C nanocomposite fibers, the MOF template-assisted strategy stimulates a remarkable leap in EMW absorption performance. The minimum reflection loss value of Cu/C-40 can reach -64.5 dB, 15.96 times lower than that of a conventional sample (Cu/C-2). The maximum effective absorption bandwidth extends to 6.08 GHz, contrasting the ineffective performance of Cu/C-2. Systematic research demonstrates that the enabled graphite-catalytic function of Cu nanoparticles collaborated with an optimized conductive network structure plays a pivotal role in creating field-induced leakage currents, facilitating conductive loss, the primary contributor to EMW dissipation. This work establishes a correlation mechanism between micromorphology and EMW loss, presenting a compelling example of customizable carbon fiber-based absorbers.