bluuebunny/crossref_metadata_2025 huggingface dataset:
Boosting the efficiency of an inverted structure halide perovskite solar cell: a numerical investigation
Authors: Tlili Wahiba , Bouazizi Sarra , Kadri Bassem , Bouich Amal , Issaoui Rabeb , Ghrissi Alia , Amlouk Mosbah , Omri Ahmed
Published: July 2024

Inverted solar cells have attracted significant attention because they have low hysteresis and are resistant to environmental variables, such as oxygen and humidity, making them more stable and long-lasting. Herein, we investigate the performance optimisation of an inverted design based on MAPbI3-xClx with the structure ITO/PTAA/MAPbI3-xClx/PC60BM/BCP/Ag by utilising SCAPS-1D, a simulation tool. Accordingly, a substantial improvement in efficiency can be achieved by optimising several factors linked to each layer’s performance in a perovskite solar cell (PSC). Total defect density, work function, thickness, and electron affinity have a significant impact on the photovoltaic response. Specifically, the impact of optimisation of the charge transport layers and the perovskite layer on the device’s performance parameters was discussed, resulting in a milestone within a remarkable increase in PCE of 21.59%, whereas the original structure’s efficiency was 6.9%. Additionally, it has been shown that aluminium can substitute silver in the top electrode of a solar cell without affecting its efficiency, allowing the development of cost-effective solar cells. The present study provides an insight in the creation of a highly stable low-cost and higher-efficiency perovskite solar cell.
Phonon-assisted leakage current of InGaN light emitting diode
Authors: Grinys Tomas , Razas Kristupas , Podlipskas Žydrūnas , Bukauskas Virginijus , Stanionytė Sandra
Published: July 2024

We report on the leakage current mechanism in a blue GaN-based light-emitting diode (LED). The device structure was grown by the MOCVD technique on a sapphire substrate. The LED was characterized through various measurements including current-voltage, electroluminescence, and secondary ion mass spectroscopy (SIMS). Capacitance-voltage measurements were employed to calculate the depletion layer thickness at different bias voltages and to analyze the doping profile in the active layer. The reverse temperature-dependent current-voltage measurements were carried out to study the leakage mechanism. The leakage current was explained by phonon-assisted tunneling of charge carriers through deep trap states. The trap energy and density of states were extracted from the application of the introduced model. Cathodoluminescence measurements were performed to evaluate the density of dislocations, which were then compared to x-ray diffraction measurements. The determined value was close to the density of states obtained from the tunneling model.
Machine learning validated compact circularly polarized dual port-MIMO antenna with polarization diversity for ku-band applications
Authors: M N Manjunath , Singh Vivek , Dwivedi Ajay Kumar , Pandey Stuti
Published: July 2024

A novel dual Port C-Shape MIMO broadband printed antenna with wide axial ratio bandwidth (ARBW) is modelled and built for Ku band Applications. The unit cell of the proposed antenna has a compact size of 25 × 26 × 0.8 mm3 engraved on RT duriod 5880 material (ε
r = 2.2, thickness of 0.8 mm). The proposed model consists of C shaped radiator, plus symbol structure and a modified ground plane. The machine learning concept is used to investigate the dimensional dependency of the plus sign on the CP behaviour. The suggested antenna shows impedance bandwidth (−10 dB) and 3-dB ARBW of 6 GHz (12 GHz to 18 GHz) which is covering the whole Ku band. The diversity performance parameters and antenna parametric investigation is also carried out to justify the MIMO identity of the proposed design. The simulated and measured counterparts are found in harmony. The strength of the proposed antenna is its planar structure, wide ARBW, polarization diversity, and wide operating Ku bandwidth.
Visually security privacy medical data protection scheme using compressive sensing and improved duffing chaotic system
Authors: Huang Shufeng , Jiang Donghua , Huang Linqing , Xiong Xiaoming , Tan Beihai , Cai Shuting
Published: July 2024

Health and medical data frequently contain sensitive patient information that must be protected. Existing visual security schemes for medical images exhibit limitations in the imperceptibility of cipher images and the performance of image reconstruction. This paper introduces and evaluates a novel approach called Visual Meaningful Image Encryption (VMIE) for securing medical images. The proposed VMIE scheme employs a chaotic system based on the Duffing equation for initial encryption. Medical images are processed and encrypted in a sparse domain. A Bidirectional Chaotic Magic Transformation (BCMT) algorithm is then applied to scramble the sparse medical images. The scrambled data undergoes compression and diffusion. An adaptive embedding strategy employing the Discrete Cosine Stockwell Transform (DCST) integrates confidential data into the host image. The performance of the proposed chaotic system is validated through theoretical analysis and numerical simulation. Simulation results, along with comparisons to existing schemes, demonstrate the efficacy of the VMIE method in enhancing visual security and its suitability for natural images. The VMIE approach presented in this paper offers a promising solution for securing medical images, effectively addressing the limitations of current visual security schemes.
Understanding magnetic interactions in SrFe12O19/CoFe2O4 nanocomposites: role of particle structure on exchange spring magnet behaviour
Authors: Idayanti N , Sugandi G , Kristiantoro T , Sudrajat N , Mulyadi D , Nuruddin A , Dedi  , Manaf A
Published: July 2024

This study explores the impact of particle structure on the magnetic properties of SrFe12O19/CoFe2O4 nanocomposites. The investigation focuses on variations in particle sizes of SrFe12O19 (SHF) and CoFe2O4 (COF) with a mass ratio of 80:20, considering micro-scale poly-crystallite particles (Pp) and nano-scale mono-crystallite particles (Mp). Four sample structures (COM1, COM2, COM3, COM4) were prepared, each with different combinations of poly-crystallite and mono-crystallite particles. Morphological analysis through scanning electron microscopy and energy-dispersive x-ray spectroscopy revealed consistent grain shape and size post-sintering. Magnetic properties analysis using Permagraph indicated that grain fineness and uniformity influence the resulting magnetic properties, with composite samples featuring nano-sized hard or soft phases showing improved M

r
, M

s
, and (BH)
max values compared to individual phases. The nanocomposite sample COM4, characterized by fine and uniform particle size, exhibited the highest remanence magnetization, M

r
(34.55 emu g−1), saturation magnetization, M
s (66.44 emu g−1), and the maximum energy product, (BH)
max (1.17 MGOe).
Spectral distortions from acoustic dissipation with non-Gaussian (or not) perturbations
Authors: Sharma Devanshu , Lesgourgues Julien , Byrnes Christian T.
Published: July 2024

A well-known route to form primordial black holes in the early universe relies on the existence of unusually large primordial curvature fluctuations, confined to a narrow range of wavelengths that would be too small to be constrained by Cosmic Microwave Background (CMB) anisotropies. This scenario would however boost the generation ofμ-type spectral distortions in the CMB due to an enhanced dissipation of acoustic waves. Previous studies ofμ-distortion bounds on the primordial spectrum were based on the assumptions of Gaussian primordial fluctuations. In this work, we push the calculation ofμ-distortions to one higher order in photon anisotropies. We discuss how to derive bounds on primordial spectrum peaks obeying non-Gaussian statistics under the assumption of local (perturbative or not) non-Gaussianity. We find that, depending on the value of the peak scale, the bounds may either remain stable or get tighter by several orders of magnitude, but only when the departure from Gaussian statistics is very strong. Our results are translated in terms of bounds on primordial supermassive black hole mass in a companion paper.
Thermalization of one-dimensional classical lattices: beyond the weakly interacting regime
Authors: Wang 王 Zhen 振 , Fu 符 Weicheng 维成 , Zhang 张 Yong 勇 , Zhao 赵 Hong 鸿
Published: July 2024

Thermalization in many-body systems, especially with strong interactions, is a central question in physics. In this work, we present a novel framework for the thermalization of interacting wave systems, distinguishing between trivial (no momentum exchange) and nontrivial interactions (significant energy redistribution). This distinction leads to a statistically equivalent model with weakened interactions. By applying this to FPUT-like models, we identify a unique double scaling of thermalization times. Crucially, our findings suggest the persistence of prethermalization in strong interactions.
The Downscaling-Upscaling Method for Load Prediction Based on Feature Prediction and Curve Clustering
Authors: Liu Ben , Dong Danhuang , Feng Yi , Lan Zhou , Zhang Peng
Published: July 2024

Load forecasting, as a classical problem, exhibits decreased accuracy in existing algorithms when the prediction window lengthens. This paper proposes a novel approach based on a downscaling-upscaling paradigm. In the downscaled process, the daily minimum load and the daily total load sequence are extracted from the load sequence. These two features are predicted using piecewise linear regression. The upscaling process involves clustering the daily load curves into multiple clusters using the K-means clustering method. The centroids of each cluster form a standard load curve library. During prediction, a standard load curve is selected from the library based on the daily load curve of the current day, and the final daily load curve prediction is obtained by applying translation and scaling operations. The translation and scaling parameters are determined by the predicted daily minimum load, predicted daily total load, and the daily load curve of the current day. Experimental results demonstrate that the proposed method achieves superior accuracy compared to existing methods for long prediction window widths.
Influence of SF6/N2 Mixed Gas Pressure on the Arc Control Ability of the Main Electrode in the Trigger Gap
Authors: Zhao Zhen , Dong Enyuan , Zhang Yifan , Li Zhibing , Zhou Ziyi , Song Yu
Published: July 2024

In the controllable self-recovery energy-absorbing apparatus of the Baihetan-Jiangsu Hybrid UHVDC Transmission Project, a 30%SF6/70%N2 mixed gas is employed as the insulating medium within the trigger gap switch. In order to mitigate surface erosion on the main electrode of the trigger gap switch, as well as the inner wall of the insulating sleeve, and to reduce the usage of SF6, an investigation into the arc control ability of the main electrode under different pressures of the mixed gas has been initiated. The motion characteristics of the arc within the gap have been simulated using a Magnetohydrodynamics (MHD) model, and the variation pattern of the main electrode’s arc control ability within the pressure range of 0.1MPa to 0.4MPa was obtained by analyzing the changes in the arc volume. The arc control ability of the main electrode is influenced by the differences in physical parameters of mixed gas at different pressures. Results indicate that the electrode’s arc control ability experiences an initial increase followed by a subsequent decrease with the rising pressure of 30%SF6/70%N2 mixed gas. Notably, within the pressure range of 0.1MPa to 0.4MPa, the main electrode exhibits the highest arc control ability when the pressure of the mixed gas is 0.3MPa.
Practical Method for Voltage Control in Active Distribution Network Based on Sensitivity
Authors: Huang Sujuan , Zhou Xun , Shen Jiangbo
Published: July 2024

The access of a large number of distributed photovoltaic power stations makes the voltage problem of the distribution network more prominent, but also provides controllable resources for the distribution network. In order to exploit the regulation potential of distributed photovoltaic power stations in active distribution networks, a practical method for voltage control based on sensitivity is proposed. The adjustment nodes and adjustment amounts are determined according to sensitivity. Based on the power flow equation, the voltage sensitivity calculation is appropriately simplified to reduce the amount of calculation. By combining forecast data and network topology, a control architecture for parallel calculation of sensitivity analysis, reactive power regulation capacity analysis, and real-time voltage control is proposed. This architecture decouples sensitivity calculation from real-time regulation and control, improving the processing speed and reliability of real-time voltage regulation and control. A case study based on a 10kV distribution network in a certain area shows that although the proposed sensitivity calculation method has some deviation, it can meet the requirements of engineering practicality and effectively achieve voltage over-limit control.
Simulation Analysis and Experimental Research on Vibration Characteristics of Series Reactors in Multiple Operating Status
Authors: Su Peiyu , Fang Cheng , Fan Delong , Feng Xiang , Wu Jing , Tang Ming , Xu Guofeng , Shi Yuchao , Dai Shiqiang , Shi Yuzhan , Ye Hanhan , Jin Lun , Han Wenfang , Han Guowen , Chen Feng , Chen Jinpeng
Published: July 2024

This article examines the vibration properties of reactors across various operational scenarios, including normal operation, interturn arc short circuit faults, and interturn metal fusion short circuit faults. It begins by analyzing the vibration mechanism of reactors, drawing upon principles of electromagnetic induction and Ampere’s law. Then, a multi condition mechanical-electromagnetic interaction model was established for the series reactor, and the axial electrodynamic force distribution of the reactor was analyzed. Finally, a vibration characteristics test platform for series reactors under multiple operating conditions was built, and the vibration velocity distribution of the reactors was analyzed. The research results indicate that under normal operating condition, the maximum vibration velocity of the reactor appears at its lower end; When the Interturn arc short circuit fault occurs, the vibration speed at different positions of the reactor increases, and the vibration velocity at the short-circuit point will significantly increase with the development of the short-circuit fault; When the interturn metal fusion short circuit fault occurs, the amplitude of the vibration signal at the short-circuit point is greater than that of the arc short-circuit vibration signal.
Research on Arcing Characteristics of Sulfur Hexafluoride Alternative Gases in Rotating Arc Ring Main Unit
Authors: Liu Bolun , Dong Enyuan , Song Yu , Zhang Lifan , Zhang Yifan
Published: July 2024

As international environmental constraints such as low carbon emissions and reduction requirements increase, there is an urgent need to seek environmentally friendly alternatives to SF6 gas. The SF6 ring main unit is widely used in the power distribution network system, highlighting the urgent need for research on environmentally friendly gas-insulated ring main units. This study simulates and compares the arc characteristics of 12 kV rotating arc ring main unit with different environmentally friendly gases, such as N2, 20%SF6/80%N2, 40%SF6/60%N2, 10%C4F7N/90%CO2. It is concluded that the arc burns most violently in N2, and the SF6 arc voltage is the highest. The specific heat at constant pressure and thermal conductivity of the gas affect the intensity of arc combustion and thus affect the arc voltage. In this paper, the causes of different gas arc characteristics are explained by analyzing the physical parameters of gas. Specifically, the isobaric specific heat and thermal conductivity of gases affect the severity of arc combustion, thereby impacting arc voltage. Moreover, viscosity plays a role in determining the rotation speed of the arc. The conclusion of this paper provides theoretical guidance on optimizing the gas component ratio of environmentally friendly gases in ring main units.
Design and Research of an Elevator Electric Brake Release Device with a Safety Detection Function
Authors: Guo Bei , Jin Laiwu
Published: July 2024

In response to the issues and defects associated with the current method of using electrical devices to open brakes for emergency rescue, a new elevator electric brake release device applicable to any elevator employing an electromechanical braking system has been designed. This device mainly consists of a car data collection unit and a brake release control unit, utilizing the STM32F103C8T6 microcontroller as the control core for elevator emergency rescue operations. The car data collection unit is responsible for gathering and transmitting data on the car’s operational state and position, while the brake release control unit evaluates the conditions for emergency rescue operations and performs real-time analysis, storage, and display of the collected data. It also decides whether to output a brake release signal. Experimental results show that when conditions for rescue operations are met, the electric brake release device can ensure the safe operation of the elevator; when abnormalities are detected, it outputs a signal to stop operations, alongside fault alarms and status displays.
A Green Approach of Zinc Oxide Nanoparticles from Dodonaea viscosa and Anti-Inflammatory Properties
Authors: Nirmala C. , Mooventhiran R. , Sivarenjith R. , Surya A. , Rejin Kumar P. , Subriya S. , Sridevi M.
Published: July 2024

The current study focused on the green synthesis of zinc oxide nanoparticle (ZnO) from the Dodonaea viscosa roots and evaluation of its anti-inflammatory properties. The presence of phytochemicals in the root extract of D. viscosa root extract was analyzed with different solvents including methanol, chloroform, aqueous and petroleum ether. The methanolic extract had higher activity among the four solvents. UV-Visible and FT-IR spectrophotometry was used to validate the synthesized ZnO. The FT-IR bands revealed the existence of several functional groups, and the UV-Vis spectrum showed theabsorption peak of 371 nm for ZnO nanoparticles. The green synthesized ZnO nanoparticles showed an anti-inflammatory activity that was confirmed by albumin denaturation and membrane stabilization. Maximum inhibition of 70% was observed from ZnO nanoparticle when compared with aspirin. IC50 value of plant extract was 36.34 µg/ml and for aspirin was found to be 36.26 µg/ml. The in vitro RBCs membrane stabilization study emphasized the anti-inflammatory activity of ZnOnanoparticles. The IC50 valve of aspirin was determined to be 21.19, whereas the plant extract was 23.49. At varying doses, the methanolic extract of D. viscosa showed efficacy in preventing heat-induced hemolysis. The three-dimensional data of the protein structure is used to predict the structural levels of proteins. Proteins of D. viscosa were analyzed using Expasy (structural prediction), Protparam server (functional characterization), and (3-D structure) SWISS MODEL, and homology modeling was used to compare them with known plant biomaterials. Bioinformation on useful proteins was also analyzed and reported. Thus, the synthesized nanoparticles possess strong anti-inflammatory activity that could be utilized in numerous pharmacological formulations.
Effective removal of Arsenic (V) using the Chromogenic Schiff base ligand.
Authors: Ganesamoorthy R , Jeyakanthan M , Gomathi R , Parameswari R , Subbramaniyan P
Published: July 2024

We report the Schiff base ligand for the decontamination of Arsenic (As-V). The chromogenic ligand namely L-1 was prepared in the easiest condensation method using 2-amino-6-nitro-benzothiazole and 10-hydroxyanthracene-9-carbaldehyde in a mild acidic DMF medium. We characterized the ligand with L-1 using the FT-IR, and 1H-NMR. A thermal study was carried out to verify the thermal stability of the Ligand L-1. The ligand showed a reasonable As-V adsorption quantity of 10 mg/g. In addition, we carried out optimization for the maximum As-V removal by adjusting the following factors concentration, dosage, pH, and temperature. The reusability confirmed our material to be reused two times for the As-V removal purpose.
Interdecadal change in the relationship between the South China late rainy season rainfall and equatorial Pacific SSTs
Authors: Tang Shaolei , Zhang Zhiyuan , Luo Jing-Jia
Published: July 2024

The South China (SC) late rainy season rainfall (SCLR) is important to people’s livelihoods and properties of this densely populated and economically developed region. Based on observation and reanalysis datasets, this study identifies that the relationship between the SCLR and equatorial Pacific SSTs (EPSSTs) experiences an interdecadal change around the late 1970s. The SCLR is negatively correlated with the eastern EPSSTs during 1948–1977 (the previous epoch) but positively correlated with the central EPSSTs during 1978–2022, especially during the last three decades 1993–2022 (the post epoch). This is due to the interdecadal change in El Niño flavors and EPSSTs-tropical Atlantic SSTs (TASSTs) relationship. With the increasing frequency of central Pacific El Niños in the post epoch, the El Niño-related warm SST anomaly center shifts from the eastern equatorial Pacific (EEP) to the central equatorial Pacific (CEP). Correspondingly, the anomalous cyclone exerted by the CEP warming reaches SC and causes rainfall surplus there (westward propagation pathway). In contrast, the EEP warming in the previous epoch cannot influence the SCLR through the westward propagation pathway, but through shifting the westerly jet southward via heating the tropical troposphere. The southward shifted westerly jet crashes the Qinghai–Tibet Plateau, triggering cyclonic circulations across the northern East Asia and North Pacific, which in turn cause anticyclonic circulations over the western SC and reduce SC rainfall (eastward propagation pathway). On the other hand, the CEP warming in the post epoch barely influence the SCLR through the eastward propagation pathway because of the enhanced negative relationship between EPSSTs and TASSTs.
Environmental impacts of lithium supply chains from Australia to China
Authors: Feng Yan , Wang Peng , Li Wen , Zhang Qian , Chen Wei-Qiang , Feng Danyi
Published: July 2024

Lithium (Li) has been widely recognized as an essential metal for clean technologies. However, the environmental impacts and emission reduction pathways of the lithium supply chain have not been clearly investigated, especially between Australia and China, where most lithium ore are mined and produced. This study analyzed and compared the environmental and human health implications of six key cross-border Li supply chains from Australia to China through material flow analysis (MFA) and life cycle assessment (LCA) methods. Key findings include: (1) approximately 30% of total Li extraction is lost in the beneficiation stage due to low recovery rates; (2) the Cattlin–Yaan routes exhibit superior environmental and human health performances than other routes attributed to lower diesel consumption, reduced electricity use, and a high chemical conversion rate; (3) the Wodgina production routes have a higher carbon footprint mainly due to low ore grade and significant diesel consumption; (4) the dominant environmental implications in the supply chain are associated with refining battery-grade lithium carbonate, driven by energy use (electricity, coal and natural gas), sulfuric acid, soda ash, and sodium hydroxide. In addition, lithium carbonate refining has the highest water consumption. Overall, the analysis highlights opportunities to improve environmental performance, advance data-poor environmental assessments, and provide insights into sustainable Li extraction.
Realization of spinful metaphotonic stokes skyrmions
Authors: Li Tianyue , Liu Mengjiao , Chen Chen , Li Xingyi , Hou Jiahao , Yang Xing , Wang Shuming , Zhu Shining
Published: July 2024

Topologically protected skyrmion textures of light have garnered significant attention due to their potential applications in next-generation high-density data storage and logic devices. However, achieving compact and tunable on-chip skyrmion modes remains a formidable challenge. In this work, we present a novel approach empowered by birefringent metasurfaces to generate and manipulate spin-multiplexed photonic skyrmion textures. By encoding independent phase profiles onto orthogonal spin states, we observe the emergence of anti-skyrmions and skyrmioniums via Stokes parameter measurements, elucidating their distinct topological characteristics. This spin-multiplexed metasurface platform not only facilitates high-dimensional multiplexing but also enables the miniaturization of topological quasi-particles, offering promising prospects for applications in optical memory, information processing, and communications.
NCNet: Deformable medical image registration network based on neighborhood cross-attention combined with multi-resolution constraints
Authors: Cui Xinxin , Xu Hao , Liu Jing , Tian Zhenyu , Yang Jianlan
Published: July 2024

Objective. Existing registration networks based on cross-attention design usually divide the image pairs to be registered into patches for input. The division and merging operations of a series of patches are difficult to maintain the topology of the deformation field and reduce the interpretability of the network. Therefore, our goal is to develop a new network architecture based on a cross-attention mechanism combined with a multi-resolution strategy to improve the accuracy and interpretability of medical image registration. Approach. We propose a new deformable image registration network NCNet based on neighborhood cross-attention combined with multi-resolution strategy. The network structure mainly consists of a multi-resolution feature encoder, a multi-head neighborhood cross-attention module and a registration decoder. The hierarchical feature extraction capability of our encoder is improved by introducing large kernel parallel convolution blocks; the cross-attention module based on neighborhood calculation is used to reduce the impact on the topology of the deformation field and double normalization is used to reduce its computational complexity. Main result. We performed atlas-based registration and inter-subject registration tasks on the public 3D brain magnetic resonance imaging datasets LPBA40 and IXI respectively. Compared with the popular VoxelMorph method, our method improves the average DSC value by 7.9% and 3.6% on LPBA40 and IXI. Compared with the popular TransMorph method, our method improves the average DSC value by 4.9% and 1.3% on LPBA40 and IXI. Significance. We proved the advantages of the neighborhood attention calculation method compared to the window attention calculation method based on partitioning patches, and analyzed the impact of the pyramid feature encoder and double normalization on network performance. This has made a valuable contribution to promoting the further development of medical image registration methods.
Individually tunable tunnelling coefficients in optical lattices using local periodic driving
Authors: Nixon Georgia M , Ünal F Nur , Schneider Ulrich
Published: July 2024

Ultracold atoms in optical lattices have emerged as powerful quantum simulators of translationally invariant systems with many applications in e.g. strongly-correlated and topological systems. However, the ability to locally tune all Hamiltonian parameters remains an outstanding goal that would enable the simulation of a wider range of quantum phenomena. Motivated by recent advances in quantum gas microscopes and optical tweezers, we here show theoretically how local control over individual tunnelling links in an optical lattice can be achieved by incorporating local time-periodic potentials. We propose to periodically modulate the on-site energy of individual lattice sites and employ Floquet theory to demonstrate how this provides full individual control over the tunnelling amplitudes in one dimension. We provide various example configurations realising interesting topological models such as extended Su–Schrieffer–Heeger models that would be challenging to realise by other means. Extending to two dimensions, we demonstrate that local periodic driving in a Lieb lattice engineers a two-dimensional (2D) network with fully controllable tunnelling magnitudes. In a three-site plaquette, we show full simultaneous control over the relative tunnelling amplitudes and the gauge-invariant flux piercing the plaquette, providing a clear stepping stone to building a fully programmable 2D tight-binding model. We also explicitly demonstrate how utilise our technique to generate a magnetic field gradient in 2D. This local modulation scheme is applicable to many different lattice geometries.
Calcineurin promotes adaptation to chronic stress through two distinct mechanisms
Authors: Flynn Mackenzie J. , Harper Nicholas W. , Li Rui , Zhu Lihua Julie , Lee Michael J. , Benanti Jennifer A.
Published: July 2024

Adaptation to environmental stress requires coordination between stress-defense programs and cell cycle progression. The immediate response to many stressors has been well characterized, but how cells survive in challenging environments long term is unknown. Here, we investigate the role of the stress-activated phosphatase calcineurin (CN) in adaptation to chronic CaCl2 stress in Saccharomyces cerevisiae. We find that prolonged exposure to CaCl2 impairs mitochondrial function and demonstrate that cells respond to this stressor using two CN-dependent mechanisms—one that requires the downstream transcription factor Crz1 and another that is Crz1 independent. Our data indicate that CN maintains cellular fitness by promoting cell cycle progression and preventing CaCl2-induced cell death. When Crz1 is present, transient CN activation suppresses cell death and promotes adaptation despite high levels of mitochondrial loss. However, in the absence of Crz1, prolonged activation of CN prevents mitochondrial loss and further cell death by upregulating glutathione biosynthesis genes thereby mitigating damage from reactive oxygen species. These findings illustrate how cells maintain long-term fitness during chronic stress and suggest that CN promotes adaptation in challenging environments by multiple mechanisms.
Sodium arsenite induces aggresome formation by promoting PICK1 BAR domain homodimer formation
Authors: Lai John Ho Chun , Tsogka Marianthi , Xia Jun
Published: July 2024

The aggresome is a perinuclear structure that sequesters misfolded proteins. It is implicated in various neurodegenerative diseases. The perinuclear structure enriched with protein interacting with C kinase 1 (PICK1) was found to be inducible by cellular stressors, colocalizing with microtubule-organizing center markers and ubiquitin, hence classifying it as an aggresome. Sodium arsenite but not arsenate was found to potently induce aggresome formation through an integrated stress response–independent pathway. In HEK293T cells, under arsenite stress, PICK1 localization to the aggresome was prioritized, and formation of PICK1 homodimers was favored. Additionally, PICK1 could enhance protein entry into aggresomes. This study shows that arsenite can induce the formation of both RNA stress granules and aggresomes at the same time, and that PICK1 shows conditional localization to aggresomes, suggesting a possible involvement of PICK1 in neurodegenerative diseases.
From Engagement to Strategic Competition
Authors: McCourt David
Published: July 2024

This chapter sketches the shift from Engagement to Strategic Competition in U.S. China policy under Trump and Biden alongside developments in U.S. Russia policy. Using the disaggregation of Engagement with China as frame, policy, and community, the chapter describes how a Trump administration staffed with anti-Engagement members of the national security community set about reframing China in the public imagination. Statements like the 2017 National Security Strategy painted a picture of Engagement as a failed, utopian strategy, through which America’s leaders—and their Engager advisors—had sought to change China. The effect was to halt Engagement as policy, letting China critics across the government develop policies likely to anger Beijing. No such re-imaging occurred in relation to Russia policy, which remained controlled by experts from the Russia-we-want group among Russia experts. What explains the emergence and consolidation of the pro- and anti-Engagers on China, and the Russia-we-have and Russia-we-want groups?
Identification and characterization of the suppressed lipid accumulation-related gene, SLA1, in the oleaginous yeast Lipomyces starkeyi
Authors: Sato Rikako , Yamazaki Harutake , Mori Kazuki , Aburatani Sachiyo , Ishiya Koji , Shida Yosuke , Ogasawara Wataru , Tashiro Kosuke , Kuhara Satoru , Takaku Hiroaki
Published: July 2024

The oleaginous yeast Lipomyces starkeyi is an attractive industrial yeast that can accumulate high amounts of intracellular lipids. Identification of genes involved in lipid accumulation contributes not only to elucidating the lipid accumulation mechanism but also to breeding industrially useful high lipid-producing strains. In this study, the suppressed lipid accumulation-related gene (SLA1) was identified as the causative gene of the sr22 mutant with decreased lipid productivity. Suppressed lipid accumulation-related gene mutation reduced gene expression in lipid biosynthesis and increased gene expression in β-oxidation. Our results suggest that SLA1 mutation may leads to decreased lipid productivity. Suppressed lipid accumulation-related gene deletion also exhibited decreased gene expression in β-oxidation and increased lipid accumulation, suggesting that SLA1 deletion is a useful tool to improve lipid accumulation in L. starkeyi for industrialization.
CircCHSY1 protects hearts against ischaemia/reperfusion injury by enhancing heme oxygenase 1 expression via miR-24-3p
Authors: Tan Jiliang , Min Jie , Jiang Yun , Liu Shenyan , Ke Minxia , Wang Zhinong , Yang Huang-Tian
Published: July 2024

Aims

Circular RNAs (circRNAs) are important players involved in a variety of physiological and pathological processes. However, their functions and mechanisms during myocardial ischaemic injury and protection remain largely unknown. We recently found significant alterations of many circRNAs including circCHSY1 following myocardial ischaemia/reperfusion (I/R) injury, whereas their exact functions are unclear. Here, we investigated the roles of circCHSY1 in the acute myocardial I/R injury and the potential mechanisms involved.

Methods and results

The expression of circCHSY1 was detected in cardiomyocytes from mouse, rat, and human embryonic stem cells (hESC-CMs). It was further up-regulated in mouse I/R (30 min/24 h) hearts, oxygen glucose deprivation/reperfusion (OGD/R, 6 h/2 h) primary neonatal rat ventricular cardiomyocytes (NRCMs) and OGD/R (48 h/2 h) hESC-CMs. Adenovirus-mediated circCHSY1 overexpression significantly decreased infarct size and lactate dehydrogenase (LDH) release in mouse I/R hearts. Consistently, circCHSY1 overexpression reduced the LDH release in the OGD/R NRCMs and hESC-CMs, improved cell viability, and preserved mitochondrial function in the OGD/R NRCMs, whereas there were no significant differences in cell viability and LDH release between the OGD/R NRCMs with and without small interfering RNA (siRNA)-mediated circCHSY1 knockdown. Mechanistically, circCHSY1 was detected to bind with miR-24-3p analysed by dual-luciferase assay and RNA pull-down assays. CircCHSY1 overexpression-mediated protective effects on cells and mitochondria in OGD/R NRCMs were reversed by the miR-24-3p mimic. Furthermore, dual-luciferase assay showed that miR-24-3p was directly bound to heme oxygenase 1 (HO1) via its 3′UTR. The protein level of HO1 was down-regulated by miR-24-3p mimic in OGD/R NRCMs but enhanced by the circCHSY1 overexpression in vitro and in vivo. Functionally, the HO1 knockdown by adenovirus in vivo and by siRNA in vitro eliminated cardioprotective effects of circCHSY1 overexpression.

Conclusion

CircCHSY1 is up-regulated following myocardial I/R injury. The higher level of circCHSY1 protects I/R hearts and cardiomyocytes. The protection of circCHSY1 is mediated through enhancement of the HO1 level, resulting in preserving mitochondrial homoeostasis via targeting miR-24-3p in cardiomyocytes. These findings suggest circCHSY1 as a protective factor.
Imaging the cerebral vasculature at different scales: translational tools to investigate the neurovascular interfaces
Authors: Carnevale Lorenzo , Lembo Giuseppe
Published: July 2024

The improvements in imaging technology opened up the possibility to investigate the structure and function of cerebral vasculature and the neurovascular unit with unprecedented precision and gaining deep insights not only on the morphology of the vessels but also regarding their function and regulation related to the cerebral activity. In this review, we will dissect the different imaging capabilities regarding the cerebrovascular tree, the neurovascular unit, the haemodynamic response function, and thus, the vascular–neuronal coupling. We will discuss both clinical and preclinical setting, with a final discussion on the current scenery in cerebrovascular imaging where magnetic resonance imaging and multimodal microscopy emerge as the most potent and versatile tools, respectively, in the clinical and preclinical context.
All-Cause Mortality and Cause-Specific Death in U.S. Long-Lived Siblings: Data From the Long Life Family Study
Authors: Yao Shanshan , Boudreau Robert M , Galvin Angéline , Murabito Joanne M , Honig Lawrence S , Perls Thomas T , Christensen Kaare , Newman Anne B
Published: July 2024

Background

This study compared the mortality risk of long-lived siblings with the U.S. population average and their spouse controls, and investigated the leading causes of death and the familial effect in death pattern.

Methods

In the Long Life Family Study (LLFS), 1 264 proband siblings (mean age 90.1, standard deviation [SD] 6.4) and 172 spouses (83.8, 7.2) from 511 U.S.-based families were recruited and followed more than 12 years. Their survival function was compared with a birth cohort-, baseline age-, sex-, and race-matched pseudo sample from U.S. census data. To examine underlying and contributing causes, we examined in detail 338 deaths with complete death adjudication at the University of Pittsburgh Field Center through the year 2018. A familial effect on survival and death patterns was examined using mixed-effect models.

Results

The LLFS siblings had better survival than the matched U.S. population average. They also had slightly but not significantly better survival than their spouses’ (HR = 1.18 [95%CI 0.94–1.49]) after adjusting for age and sex. Age at death ranged from 75 to 104 years, mean 91.4. The leading causes of death were cardiovascular disease (33.1%), dementia (22.2%), and cancer (10.7%). Mixed effect model shows a significant random effect of family in survival, with adjustment of baseline age and sex. There was no significant familial effect in the underlying cause of death or conditions directly contributing to death among siblings recruited by the University of Pittsburgh Field Center.

Conclusions

Our findings demonstrate a higher survival in the LLFS siblings than the U.S. census data, with a familial component of survival. We did not find significant correspondence in causes of death between siblings within families.
Mild Cognitive Impairment and Suicidal Ideation Among Adults Aged 65 Years or Older From Low- and Middle-Income Countries
Authors: Smith Lee , López Sánchez Guillermo Felipe , Soysal Pinar , Veronese Nicola , Jacob Louis , Kostev Karel , Rahmati Masoud , Barnett Yvonne , Keyes Helen , Gibson Poppy , Butler Laurie , Shin Jae Il , Koyanagi Ai
Published: July 2024

Objectives

Mild cognitive impairment (MCI) is a unique indicator of underlying distress that may be strongly associated with suicide risk. Despite this, to date, no study has examined the association between MCI and suicidal ideation. Therefore, the present study aimed to examine the association between MCI and suicidal ideation among adults aged ≥65 years from 6 low- and middle-income countries (LMICs; China, Ghana, India, Mexico, Russia, and South Africa).

Methods

Cross-sectional, nationally representative data from the World Health Organization’s Study on Global Ageing and Adult Health were analyzed. MCI was defined using the National Institute on Aging-Alzheimer’s Association criteria. Self-reported information on past 12-month suicidal ideation was collected. Multivariable logistic regression and meta-analysis were conducted to assess associations.

Results

Data on 13,623 individuals aged ≥65 years were analyzed. The prevalence of suicidal ideation ranged from 0.5% in China to 6.0% in India, whereas the range of the prevalence of MCI was 9.7% (Ghana) to 26.4% (China). After adjustment for potential confounders, MCI was significantly associated with 1.66 (95% confidence interval [95% CI] = 1.12–2.46) times higher odds for suicidal ideation.

Discussion

Mild cognitive impairment was significantly associated with higher odds for suicidal ideation among older adults in LMICs. Future longitudinal studies from LMICs are necessary to assess whether MCI is a risk factor for suicidal ideation.
Navigating normalcy: designing personal health visualizations for pediatric kidney transplant recipients and caregivers
Authors: Jeffs Lily V , Dunbar Julia C , Syed Sanaa , Ng Chelsea , Pollack Ari H
Published: July 2024

Objectives

Patients with chronic illnesses, including kidney disease, consider their sense of normalcy when evaluating their health. Although this concept is a key indicator of their self-determined well-being, they struggle to understand if their experience is typical. To address this challenge, we set out to explore how to design personal health visualizations that aid participants in better understanding their experiences post-transplant, identifying barriers to normalcy, and achieving their desired medical outcomes.

Materials and Methods

Pediatric kidney transplant patients and their caregivers participated in three asynchronous design sessions involving sharing experiences, presenting symbolic objects, and providing feedback on visualizations to understand their perceptions of normalcy post-transplant. Data analysis of design session 1 and 2 comprised deductive and inductive analysis. We used affinity diagramming to identify thematic areas about participants’ transplant experiences. Comprehension of design session three normalcy visualizations was also evaluated.

Results

Participants effectively engaged in the design sessions, revealing diverse perspectives on their experiences. We found there is a significant need for visualizations that depict normalcy to better inform patients and caregivers about their health.

Discussion

Normalcy Visualizations should incorporate three key design principles: personal values, facilitating peer and self-comparison, and seamlessly communicating abstract concepts to help youth kidney transplant recipients comprehend and contextualize if their transplant experience is normal and what normalcy means to them.

Conclusion

By incorporating holistic aspects of patients’ and caregivers’ lives into personal health visualizations, they can be cognizant of their progress to normalcy and empowered to make decisions that help them feel normal.
Quantitative trait loci concentrate in specific regions of the Mexican cavefish genome and reveal key candidate genes for cave-associated evolution
Authors: Wiese Jonathan , Richards Emilie , Kowalko Johanna E , McGaugh Suzanne E
Published: July 2024

A major goal of modern biology is connecting phenotype with its underlying genetic basis. The Mexican cavefish (Astyanax mexicanus), a characin fish species comprised of a surface ecotype and a cave-derived ecotype, is well suited as a model to study the genetic mechanisms underlying adaptation to extreme environments. Here, we map 206 previously published quantitative trait loci (QTL) for cave-derived traits in A. mexicanus to the newest version of the surface fish genome assembly, AstMex3. These analyses revealed that QTL clusters in the genome more than expected by chance, and this clustering is not explained by the distribution of genes in the genome. To investigate whether certain characteristics of the genome facilitate phenotypic evolution, we tested whether genomic characteristics associated with increased opportunities for mutation, such as highly mutagenic CpG sites, are reliable predictors of the sites of trait evolution but did not find any significant trends. Finally, we combined the QTL map with previously collected expression and selection data to identify 36 candidate genes that may underlie the repeated evolution of cave phenotypes, including rgrb, which is predicted to be involved in phototransduction. We found this gene has disrupted exons in all non-hybrid cave populations but intact reading frames in surface fish. Overall, our results suggest specific regions of the genome may play significant roles in driving adaptation to the cave environment in A. mexicanus and demonstrate how this compiled dataset can facilitate our understanding of the genetic basis of repeated evolution in the Mexican cavefish.
Perspectives of pediatric oncologists on referral for CAR-T therapy: a mixed methods pilot study
Authors: Hall Anurekha G , Duenas Devan M , Voutsinas Jenna , Wu Qian , Lamble Adam J , Gruber Elizabeth , Wilfond Benjamin , Park Julie R , Agrawal Anurag K , Marron Jonathan M
Published: July 2024

Background

Receipt of chimeric antigen receptor T-cell (CAR-T) therapy at an institution different from the primary oncologist’s institution is a complex, multistep process. Referral by oncologists plays an important role in the process but may be susceptible to bias.

Methods

Oncologists who previously referred patients for CAR-T therapy at 5 pediatric hospitals were sent surveys by email exploring their CAR-T referral practices. Descriptive statistics were generated, and multivariate analyses examined associations among oncologist characteristics, familiarity with CAR-T therapy, and referral practices. We conducted semistructured interviews with a subset of participants and used thematic analysis to code transcripts.

Results

Sixty-eight oncologists completed the survey; 77% expressed being “very familiar” with CAR-T therapy. Hispanic oncologists and oncologists at institutions with 50 or fewer new diagnoses per year were more likely to identify as less familiar with CAR-T therapy (odds ratio [OR] = 64.3, 95% confidence interval [CI] = 2.45 to 10 452.50, P = .04 and OR = 24.5, 95% CI = 3.3 to 317.3, P = .005, respectively). In total, 38% of respondents considered nonclinical features (compliance, social support, resources, insurance, language, education, and race or ethnicity) influential in referral decisions. Oncologists who were Hispanic and oncologists who had been practicing for 20 or more years were more likely to consider these features significantly influential (OR = 14.52, 95% CI = 1.49 to 358.66, P = .04 and OR = 6.76, 95% CI = 1.18 to 50.5, P = .04). Nine oncologists completed in-depth interviews; common themes included barriers and concerns regarding CAR-T therapy referral, the value of an established relationship with a CAR-T therapy center, and poor communication after CAR-T therapy.

Conclusions

Nearly 40% of oncologists consider nonclinical features significantly influential when deciding to refer patients for CAR-T therapy, raising concern for bias in the referral process. Establishing formal partnerships with CAR-T therapy centers may help address physician barriers in referral.