bluuebunny/crossref_metadata_2025 huggingface dataset:
HoloTile light engine: new digital holographic modalities and applications
Authors: Glückstad Jesper , Gejl Madsen Andreas Erik
Published: February 2024

HoloTile is a patented computer generated holography approach with the aim of reducing the speckle noise caused by the overlap of the non-trivial physical extent of the point spread function in Fourier holographic systems from adjacent frequency components. By combining tiling of phase-only of rapidly generated sub-holograms with a PSF-shaping phase profile, each frequency component—or output ‘pixel’— in the Fourier domain is shaped to a desired non-overlapping profile. In this paper, we show the high-resolution, speckle-reduced reconstructions that can be achieved with HoloTile, as well as present new HoloTile modalities, including an expanded list of PSF options with new key properties. In addition, we discuss numerous applications for which HoloTile, its rapid hologram generation, and the new PSF options may be an ideal fit, including optical trapping and manipulation of particles, volumetric additive printing, information transfer and quantum communication.
Analysis of torsional buckling of a cylindrical sandwich shell with a magnetorheological fluid core layer
Authors: Kashipazha Masoud , Kheirikhah Mohammadmehdi , Meshkinabadi Saeed
Published: February 2024

This study is an attempt to analyze the torsion buckling of a structure consisting of a cylindrical sandwich shell with two isotropic face sheets that surround a magnetorheological fluid (MRF) core layer. In this analysis, the simply supported boundary conditions were considered for the edges of the face sheets and the core layer. The components of displacement were calculated using the first-order shear deformation theory, and the governing equations were derived using Hamilton’s principle and were solved drawing upon the Galerkin method. The parameters of interest were magnetic field, buckling analysis, torsional buckling convergence, h/L ratio, ht/h ratio, and rt/L ratio. The equations obtained from MATLAB were verified using ABAQUS owing to the absence of any similar study in the existing literature. A good agreement was observed in terms of torsional buckling, indicating the robustness of the proposed structure. As smart sandwich structures are broadly used in robotics and aerospace, this structure can be a good choice thanks to its lightness (resulting from the thinness of the face sheets and hollowness) and strength and resistance (contributed by MRF core layer), which can be modified with the application of different magnetic fields.
Simulation and analysis of inverse-mode operation of single event transient mechanisms on NPN-SiGe HBT
Authors: Adekoya Mathew Adefusika , Liu Shuhuan , Wang Xuan , Xing Tian , Li Haodi , Meng Fanjun , Du Xiaozhi , Li Zhuoqi , Huang Taiyi
Published: February 2024

This work presents the characteristics of the single event transient (SET) induced by a single heavy ion in the inverse mode NPN-SiGe HBT simulated with the Silvaco TCAD toolkit. The designed SiGe HBT technology structure was built on the DevEdit simulator and simulated on Deckbuild using device and radiation effect simulations. The characteristics of device SET distribution, including transient pulse current, corresponding collection charge, pulse current peak, and full width at half maximum (FWHM) levels, etc, were simulated and compared as they changed with heavy ion LETs (0.2 pC μm−1 ∼ 1.0 pC μm−1), striking angles (30° ∼ 120°), and device emitter bias voltage settings (0.6 V ∼ 1.8 V). Meanwhile, the electrostatic potential distribution was found to be impacted by the heavy ion SET at the initial time moment when the heavy ion began to strike the surface of the device. The mechanisms for SET variation and its influence on the device potential under different conditions were primarily analyzed and discussed.
Rational molecular engineering towards efficient heterojunction solar cells based on organic molecular acceptors
Authors: Zhang 张 Kaiyan 凯彦 , Song 宋 Peng 朋 , Ma 马 Fengcai 凤才 , Li 李 Yuanzuo 源作
Published: February 2024

The selection of photoactive layer materials for organic solar cells (OSCs) is essential for the photoelectric conversion process. It is well known that chlorophyll is an abundant pigment in nature and is extremely valuable for photosynthesis. However, there is little research on how to improve the efficiency of chlorophyll-based OSCs by matching chlorophyll derivatives with excellent non-fullerene acceptors to form heterojunctions. Therefore in this study we utilize a chlorophyll derivative, Ce6Me3, as a donor material and investigate the performance of its heterojunction with acceptor materials. Through density functional theory, the photoelectric performances of acceptors, including the fullerene derivative PC71BM and the terminal halogenated non-fullerene DTBCIC series, are compared in detail. It is found that DTBCIC-Cl has better planarity, light absorption, electron affinity, charge reorganization energy and charge mobility than others. Ce6Me3 has good energy level matching and absorption spectral complementarity with the investigated acceptor molecules and also shows good electron donor properties. Furthermore, the designed Ce6Me3/DTBCIC interfaces have improved charge separation and reorganization rates (K
CS/K
CR) compared with the Ce6Me3/PC71BM interface. This research provides a theoretical basis for the design of photoactive layer materials for chlorophyll-based OSCs.
Synthesis and nitrogen content regulation of diamond in a high-pressure hydrogen-rich environment
Authors: Huang 黄 Guofeng 国锋 , Chen 陈 Liangchao 良超 , Fang 房 Chao 超
Published: February 2024

The regulating nitrogen content of diamond in a hydrogen-rich high-temperature and high-pressure (HPHT) growth environment was systematically investigated in this work by developing three growth systems, namely, “FeNi+Ti”, “FeNi+C3N6H6”, and “FeNi+Ti+C3N6H6”. Optical microscopy, infrared spectroscopy, and photoluminescence (PL) spectroscopy measurements were conducted to analyze the spectroscopic characteristics of diamonds grown in these three systems. From our analysis, it was demonstrated that the presence of hydrogen in the sp3 hybrid C–H does not directly affect the color of the diamond and facilitates the increase of the nitrogen-vacancy (NV) center concentration in a high-nitrogen-content diamond. In addition, titanium plays an important role in nitrogen removal, while its impact on hydrogen doping within the diamond lattice is insignificant. Most importantly, by regulating the ratio of nitrogen impurities that coexist in the nitrogen and hydrogen HPHT environment, the production of hydrogenous IIa-type diamond, hydrogenous Ib-type diamond, and hydrogenous high-nitrogen-type diamonds was achieved with a nitrogen content of less than 1 ppm to 1600 ppm.
Exceptional points and quantum dynamics in a non-Hermitian two-qubit system
Authors: Zhang 张 Yi-Xi 益玺 , Zhang 张 Zhen-Tao 振涛 , Yang 杨 Zhen-Shan 震山 , Wei 魏 Xiao-Zhi 晓志 , Liang 梁 Bao-Long 宝龙
Published: February 2024

We study the exceptional-point (EP) structure and the associated quantum dynamics in a system consisting of a non-Hermitian qubit and a Hermitian qubit. We find that the system possesses two sets of EPs, which divide the system-parameter space into

P
T

-symmetry unbroken, partially broken and fully broken regimes, each with distinct quantum-dynamics characteristics. Particularly, in the partially broken regime, while the

P
T

-symmetry is generally broken in the whole four-dimensional Hilbert space, it is preserved in a two-dimensional subspace such that the quantum dynamics in the subspace are similar to those in the

P
T

-symmetry unbroken regime. In addition, we reveal that the competition between the inter-qubit coupling and the intra-qubit driving gives rise to a complex pattern in the EP variation with system parameters.
Global dust density in two-dimensional complex plasma
Authors: Zhao 赵 Yi-Zhen 逸真 , Liu 刘 Song-Fen 松芬 , Kong 孔 Wei 伟 , Yang 杨 Fang 芳
Published: February 2024

The driven-dissipative Langevin dynamics simulation is used to produce a two-dimensional (2D) dense cloud, which is composed of charged dust particles trapped in a quadratic potential. A 2D mesh grid is built to analyze the center-to-wall dust density. It is found that the local dust density in the outer region relative to that of the inner region is more nonuniform, being consistent with the feature of quadratic potential. The dependences of the global dust density on equilibrium temperature, particle size, confinement strength, and confinement shape are investigated. It is found that the particle size, the confinement strength, and the confinement shape strongly affect the global dust density, while the equilibrium temperature plays a minor effect on it. In the direction where there is a stronger confinement, the dust density gradient is bigger.
A historical overview of nano-optics: From near-field optics to plasmonics
Authors: Deng 邓 Miao-Yi 妙怡 , Zhu 朱 Xing 星
Published: February 2024

Nano-optics is an emergent research field in physics that appeared in the 1980s, which deals with light–matter optical interactions at the nanometer scale. In early studies of nano-optics, the main concern focus is to obtain higher optical resolution over the diffraction limit. The researches of near-field imaging and spectroscopy based on scanning near-field optical microscopy (SNOM) are developed. The exploration of improving SNOM probe for near-field detection leads to the emergence of surface plasmons. In the sense of resolution and wider application, there has been a significant transition from seeking higher resolution microscopy to plasmonic near-field modulations in the nano-optics community during the nano-optic development. Nowadays, studies of nano-optics prefer the investigation of plasmonics in different material systems. In this article, the history of the development of near-field optics is briefly reviewed. The difficulties of conventional SNOM to achieve higher resolution are discussed. As an alternative solution, surface plasmons have shown the advantages of higher resolution, wider application, and flexible nano-optical modulation for new devices. The typical studies in different periods are introduced and characteristics of nano-optics in each stage are analyzed. In this way, the evolution progress from near-field optics to plasmonics of nano-optics research is presented. The future development of nano-optics is discussed then.
Teukolsky-like equations with various spins in spherically symmetric spacetime*
Authors: Guo 郭 Ya 亚 , Nakajima Hiroaki , Lin 林 Wenbin 文斌
Published: February 2024

We study wave equations with various spins on the background of a general spherically symmetric spacetime. We obtain the unified expression of the Teukolsky-like master equations and the corresponding radial equations with the general spins. We also discuss the gauge dependence in the gravitational-wave equations, which have appeared in previous studies.
Morphological Classification of Infrared Galaxies Based on WISE
Authors: Pan Zhi-Ren , Qiu Bo , Liu Cui-Xiang , Luo A-Li , Jiang Xia , Guo Xiao-Yu
Published: February 2024

This study introduces a novel convolutional neural network, the WISE Galaxy Classification Network (WGC), for classifying spiral and elliptical galaxies using Wide-field Infrared Survey Explorer (WISE) images. WGC attains an accuracy of 89.03%, surpassing the combined use of K-means or SVM with the Color–Color method in more accurately identifying galaxy morphologies. The enhanced variant, WGC_mag, integrates magnitude parameters with image features, further boosting the accuracy to 89.89%. The research also delves into the criteria for galaxy classification, discovering that WGC primarily categorizes dust-rich images as elliptical galaxies, corresponding to their lower star formation rates, and classifies less dusty images as spiral galaxies. The paper explores the consistency and complementarity of WISE infrared images with SDSS optical images in galaxy morphology classification. The SDSS Galaxy Classification Network (SGC), trained on SDSS images, achieved an accuracy of 94.64%. The accuracy reached 99.30% when predictions from SGC and WGC were consistent. Leveraging the complementarity of features in WISE and SDSS images, a novel variant of a classifier, namely the Multi-band Galaxy Morphology Integrated Classifier, has been developed. This classifier elevates the overall prediction accuracy to 95.39%. Lastly, the versatility of WGC was validated in other data sets. On the HyperLEDA data set, the distinction between elliptical galaxies and Sc, Scd and Sd spiral galaxies was most pronounced, achieving an accuracy of 90%, surpassing the classification results of the Galaxy Zoo 2 labeled WISE data set. This research not only demonstrates the effectiveness of WISE images in galaxy morphology classification but also represents an attempt to integrate multi-band astronomical data to enhance understanding of galaxy structures and evolution.
Reflector Deformation Measurement and Correction Methodology of Large Antenna Based on Phased Array Feed
Authors: Wang Zan , Kong De-Qing , Zhang Hong-Bo , Su Yan , Zhu Xin-Ying , Wang Cong-Si , Liu Yu-Chen
Published: February 2024

To solve the problem of time-consuming measurement and correction of large antennas’ reflector deformation, a new microwave holography methodology based on a Phased Array Feed (PAF) is proposed. Starting from the known expression of receiving signals in microwave holography, the theory of PAF holography is derived through Geometrical Optics. Reflector deformation, as well as pointing deviation and subreflector offset, can be calculated out by applying the derived equations. A measurement and correction system based on PAF holography is depicted, and two kinds of measurement methods are illustrated. The proposed measurement methodology is verified by numerical simulation, and its measurement error is analyzed. The results indicate that our proposed methodology is feasible, especially for Cassegrain antennas.
Research on new energy power prediction technology based on privacy protection
Authors: Zhou Ziguan , Zhu Yaping , Liu Zhu , Li Xuming , Huang Chao , Wang Miao
Published: February 2024

New energy power prediction is an important part of the transition process from the traditional power system to the new power system. How to improve the power prediction accuracy while ensuring that data privacy is not leaked is an issue that needs to be focused on. Based on this, this paper constructs a new energy power prediction model integrating NGBoost and LSTM by screening the optimal feature sequences as model inputs, then encrypting the transmission aggregation process of model parameters and finally testing and evaluating the scheme based on a real data set. Experiments show that the scheme proposed in this paper not only improves data confidentiality to a certain extent compared with a single prediction model, but also the model is characterized by robustness and high prediction accuracy.
Transmission line fault detection based on anchor frame a priori and attention mechanism
Authors: Zhao Yang
Published: February 2024

YOLO target detection algorithm is the mainstream method for image-based defect detection of transmission line insulators. However, the existing model complexity is large. A reasonable and effective parameter compression method is urgently needed as a prerequisite to lay the foundation for solving the dilemma of UAV edge equipment deployment. At the same time, the insulator defect images taken by UAVs have complex backgrounds and small defect sizes, which are prone to misdetection and omission. It is needed to improve the channel domain of the CBAM (convolution block attention module) attention mechanism and solve its problem of missing channel information due to dimensionality reduction. The improved CBAM is added to the backbone network of YOLOv5s. The goal is to enable the model to identify and pinpoint the critical objectives with greater precision. The model is combined with Cross Entropy Loss and Lovasz-Softmax Loss weighting, which makes the network converge more stably during the training process, and the accuracy rate is also somewhat improved.
Identification of Intermittent Ground Fault Lines in Medium Voltage Shipboard Power Systems
Authors: Song Yawei , Luo Yuwen , Yan Kai , Zhu Pei , Ye Zehao , He Chengwei
Published: February 2024

To locate increasingly frequent intermittent ground faults in medium-voltage shipboard power systems, this study proposes a fault branch selection method using wavelet analysis. By analyzing transient fault current characteristics in ship medium-voltage grids, this method utilizes wavelet analysis tools to extract features and obtain modulus maxima of branch currents. Based on a dual threshold detection strategy, the fault branch is then identified. The feasibility and validity of the proposed method are verified through simulations on the Matlab/Simulink platform. The simulation results demonstrate the capability of the wavelet analysis approach to accurately locate intermittent ground faults in ship medium-voltage power systems. This research provides an effective solution for fault branch selection of intermittent grounding faults in ship medium-voltage grids.
Rapid Recovery Technology of SF6/N2 Mixed Insulation Gas in Electrical Equipment
Authors: Fu Lijun , Guan Yanling , Zhang Liang , Wei Bing , Li Guoxin , Chi Jingyuan , Wang Han
Published: February 2024

SF6 mixed gas is widely used as an insulation and arc extinguishing medium in electrical equipment in cold regions of northern China. Due to its low liquefaction temperature, existing gas recovery technologies are unable to achieve efficient and rapid recovery of SF6/N2 mixed insulation gases. In response to this challenge, a two-stage membrane separation and recovery technology has been proposed, which can efficiently and quickly separate SF6 and N2 from the mixed gas. The volume fraction (V/V) of obtained product SF6 gas reaches 90%, and the use of compression and refrigeration units can achieve rapid filling of 50 m3/h mixed gas. At the same time, the enrichment and recovery of trace SF6 gas in the exhaust gas are achieved. After enrichment, the volume fraction (V/V) of SF6 gas reaches 92%, and the volume fraction (V/V) of SF6 gas in the emptied mixed gas is 600 μL/L, far below the national standard value, solving the problems in actual production.
Simulation analysis of energy metering error of non-vehicle charger
Authors: Lu An , Yuan Jing , Gao Zhang , Yu Ling
Published: February 2024

This paper studies three methods of DC energy measurement for non-vehicle chargers, namely, the average value method, effective value method, and time domain integration method, introduces the definition of ripple, and analyzes the characteristics of constant voltage, constant current charging mode and pulse charging mode of electric vehicles, providing an algorithm basis for the establishment of DC energy metering error model and simulation analysis. This paper studies high-power DC energy measurement algorithms with ripple parameters, analyzes the error characteristics of various algorithms, summarizes the relevant laws, and provides a theoretical basis for the design of a high-precision DC metering module under the influence of ripple.
Research on performance state evaluation of circuit breaker energy storage spring based on intelligent algorithm
Authors: Xie Lingdong , Zhou Honghui , Zhao Tielin , Zhang Xibo , Ying Jianguo , Wang Junhua
Published: February 2024

The performance state evaluation method of circuit breaker energy storage spring mainly judges its performance state indirectly by measuring the pre-tightening force or pre-pressure of the spring. However, there may be some errors in this indirect measurement method, which will affect the accuracy of the evaluation results. Therefore, the performance state evaluation based on intelligent algorithm is proposed. Select the evaluation characteristic quantity of performance state, calculate the energy storage spring impulse according to the momentum theorem, and obtain the pressure value of the closing energy storage spring through the pressure sensor as the evaluation quantity reflecting the energy storage spring performance state. The BP neural network is established, and the fireworks algorithm is applied to the BP neural network to optimize the initial weight and threshold, so as to realize the performance state evaluation of energy storage spring based on BP neural network. The experimental results show that the spring energy release speed of the proposed method is in the range of 0 - 1.0m/s, and the estimated spring pressure value is basically consistent with the actual value.
Experimental study on damping characteristics of the particle dampers with damping rod and soft inside wall
Authors: Guo Yangyang , Liu Kai , Hou Gaoyan
Published: February 2024

In the perpendicular simple sinusoidal excitation, the damping characteristics of the soft-wall particle damper with a damping rod were experimentally investigated by controlling the acceleration amplitude and vibration frequency of the damper motion and measuring the force and acceleration signals. The experimental results show that the loss power of the damper increases monotonically with the rise of the excitation acceleration amplitude, and the effective mass shows the change of “gentle decrease-critical point-decrease”. As the driving frequency rises, the loss power progressively decreases, and the effective mass does not change significantly. By analyzing the damping characteristics of different dampers, it shows that the damping effectiveness of the soft inside wall particle damper with a damping rod is obviously better.
Design and Implementation of Automatic Airport Inspection System of Vehicle-mounted Rotor UAV
Authors: Yao Shaocan , Zhang Yong , Xi Xiaopeng , Li Xueling , Li Zhilin
Published: February 2024

A distributed UAV automatic airport inspection system, with the advantages of unmanned autonomous inspection operation, is widely used in power patrol, highway inspection, forest fire monitoring, and other fields. The disadvantage is that the operating radius distance is limited, with the multi-fixed site layout and high cost. In this paper, a vehicle-mounted rotor UAV automatic airport inspection system is designed, which can flexibly move the operation site and increase the operation radius. This inspection system is based on 5G wireless communication control technology and can remotely control the UAV. After the operation is completed, the UAV is automatically stored, charged, and maintained, and other functions have a good application prospect.
Deposition of carbon nanolayers by PECVD on ceramic substrates
Authors: Ivanov I , Marinov S , Popov G , Abrashev M , Kirilov K , Kiss’ovski Zh
Published: February 2024

Graphene layers and nanostructures were deposited on silicon dioxide (SiO2/Si) and silicon carbide (SiC) substrates at low gas pressure (1 – 5 torr) by microwave discharge PECVD (Plasma Enhanced Chemical Vapor Deposition). The advantage of this method is the relatively low temperature (600-700°C) of the substrate in the deposition process. The diffusion processes of hydrocarbon radicals on the surface of the substrates have a significant effect on the homogeneity of deposited structures. The deposited graphene nanotubes on SiC were analyzed by scanning electron microscope (SEM) and Raman spectroscopy is applied for characterization of the graphene layers. The deposited carbon layers on SiO2 were analyzed by atomic force microscope and their thickness (12-20 nm) were determined.
Surface structuring and in situ synthesis of nanoparticles by ultrashort laser processing on hydroxyapatite
Authors: Aceti D M , Filipov E , Lasgorceix M , Daskalova A
Published: February 2024

Ultrashort laser pulses represent a versatile tool that finds application in a variety of fields allowing precise and controlled modification of any kind of materials. The material surface modification, by inducing the formation of micro and nanostructures or providing chemical changes, or its functionalization with other materials, in form of nanoparticles, strongly affects the behavior and performances of such materials. The surface structuring and the synthesis and deposition of metallic nanoparticles has both been obtained by laser exposure. The two processes are performed consecutively, on hydroxyapatite sample surface. The synthesis of silver nanoparticles (AgNPs) takes place on the sample surface, while immersed in a solution of silver nitrate (AgNO3), by laser-induced multiphoton photoreduction of silver ions (Ag+).
A study of cavitation erosion resistance of an ion nitrided titanium alloy by means of the vibration and rotating disk methods
Authors: Safonov V , Zykova A , Steller J , Szkodo M , Gajowiec G , Chmiel J , Varhoshkov A , Klimenko I
Published: February 2024

In this work, a comparative analysis of the cavitation erosion resistance of the Ti–6.7Al–2.5Mo–1.8Cr–0.5Fe–0.25Si alloy (known as brand VT3-1) before and after low-temperature ion nitriding is carried out. Two test methods were applied, using vibrative (ASTM G-32) and rotating disk rigs, respectively. The kinetic dependences of the erosive destruction of samples of titanium alloy VT3-1 in the initial state, after ion nitriding and stainless steel AISI 321 were obtained. A study of the microstructure, hardness and surface morphology was carried out. The samples were examined using optical and scanning electron microscopy. The relationship between mass loss and cavitation erosion duration was experimentally determined and analyzed. The erosion rate on a rotating disk stand is much higher than during vibration tests. A large cavitation load gradient provides additional opportunities for analyzing the durability of materials and coatings using this method.
Elemental composition and structural characteristics of Bio-active™ orthodontic archwire
Authors: Stoyanova-Ivanova A , Mihaylov V , Georgiev V , Georgieva M , Petrov V , Andreeva L , Petrova N , Mikli V
Published: February 2024

The Bio-active™ archwires are the latest generation multi-force orthodontic archwires made of a Ni-Ti alloy. It is of particular importance to orthodontists to know what their composition and structural characteristics are so that they can determine which one is suitable for a given stage of orthodontic treatment. The aim of this work is to characterize as-received Bio-active™ archwires, consisting of three segments (anterior, bicuspid and posterior), by determining their physicochemical properties. Laser-induced breakdown spectroscopy (LIBS) was used to determine the elemental composition in the three different segments of the archwires, along with X-ray diffraction analysis (XRD), scanning electronic microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and differential scanning calorimetry (DSC). A LIBS and EDX analysis of the elemental composition showed that nickel (55wt.%) and titanium (45wt.%) are the main elements, and in some segments Fe and Cr registered as trace elements. A XRD analysis, at room temperature, showed two similar peaks, characteristic of a Ni-Ti alloy, proof that the archwire is an austenite phase. The DSC data was obtained by measuring the Af temperatures for each segment (heated up to +80°C and cooled down to -80°C), showing that they can be classified as martensite-active wires (heat-activated). Based on that a recommendation can be made to cool down the unused, as-received archwires before clinical use to ensure that they will fit in the brackets easier. On the surface of the as-received archwires small grains can be seen from the SEM micrographs. The obtained results provide orthodontists important information regarding the physicochemical properties of the as-received Bio-active™ archwires. The results can also serve as a foundation for future research on the elemental composition and morphology of clinically applied Bio-active™ archwires.
Physicochemical study of natural zeolite modified with lavender essential oil
Authors: Tsacheva Ivelina , Gigova Adriana , Dimitrov Ognian , Dimitrova Mariela , Uzun Dzhamal
Published: February 2024

Zeolite-containing nanocomposites as candidates for Lavender oil delivery systems were investigated. The nanocomposite samples and lavender oil delivery systems were investigated by pore size distribution and X-ray diffraction (XRD), the specific surface area with Brunauer-Emmett-Teller (BET), Fourier-transform infrared (FT-IR) spectrometer, energy-dispersive spectroscopy (EDX) analysis and Scanning Electron Microscopy (SEM). These initial results could significantly contribute to the further development of applications for lavender essential oil delivery systems based on natural zeolites as innovative bioactive products.
Substitution effects on Y-type hexaferrites’ magnetic characteristics
Authors: Georgieva B , Kolev S , Krezhov K , Ghelev Ch , Kovacheva D , Tzvetkov P , Tran L-M , Babij M , Koutzarova T
Published: February 2024

The effect is discussed of the partial replacement of the Me2+ in the Y-type hexaferrite crystal structure with non-magnetic (Mg2+) and magnetic (Ni2+) cations on the observed magnetic characteristics of Ba0.5Sr1.5Me2Fe12O22. Y-type hexaferrite powder material was prepared by citric acid sol-gel self-ignition and sintering at 1170 °C in air to reach Ba0.5Sr1.5MgxNiyFe12O22. To determine the magnetic phase transitions, the ZFC/FC magnetisation was followed in magnetic fields of 50 Oe and 100 Oe between 4.2 K and 300 K; this was complemented with hysteresis loops recorded at the end temperatures. The results show that combining the magnetic Ni2+ with the nonmagnetic Mg2+ in Ba0.5Sr1.5 Me2Fe12O22 can be effective in controlling the magnetic interactions to regulate the temperature of the magnetic transition from helical to ferrimagnetic arrangement above room temperature.
A well plate-based GelMA photo-crosslinking system with tunable hydrogel mechanical properties to regulate the PTH-mediated osteogenic fate
Authors: Paek Kyurim , Woo Sangwook , Song Seung Jae , Kim Min Kyeong , Yi Keewook , Chung Seok , Kim Jeong Ah
Published: February 2024

Versatile and efficient regulation of the mechanical properties of the extracellular matrix is crucial not only for understanding the dynamic changes in biological systems, but also for obtaining precise and effective cellular responses in drug testing. In this study, we developed a well plate-based hydrogel photo-crosslinking system to effectively control the mechanical properties of hydrogels and perform high-throughput assays. We improved cell biocompatibility by using gelatin methacryloyl (GelMA) with a visible light photo-crosslinking method. Multiple cell-laden GelMA hydrogels were simultaneously and uniformly created using multi-arrayed 520 nm light-emitting diodes in a well plate format. The elastic modulus of the hydrogels can be widely adjusted (0.5–30 kPa) using a photo-crosslinking system capable of independently controlling the light intensity or exposure time for multiple samples. We demonstrate the feasibility of our system by observing enhanced bone differentiation of human mesenchymal stem cells (hMSCs) cultured on stiffer hydrogels. Additionally, we observed that the osteogenic fate of hMSCs, affected by the different mechanical properties of the gel, was regulated by parathyroid hormone (PTH). Notably, in response to PTH, hMSCs in a high-stiffness microenvironment upregulate osteogenic differentiation while exhibiting increased proliferation in a low-stiffness microenvironment. Overall, the developed system enables the generation of multiple cell-laden three-dimensional cell culture models with diverse mechanical properties and holds significant potential for expansion into drug testing.
Yearly population data at census tract level revealed that more people are now living in highly fire-prone zones in California, USA
Authors: Laszewski Slade , Jia Shenyue , Viner Jessica , Ho Wesley , Hoover Brian , Kim Seung Hee , Kafatos Menas C
Published: February 2024

In California (CA), the wildland-urban interface (WUI) faces escalating challenges due to surging population and real estate development. This study evaluates communities along CA’s WUI that have witnessed substantial population growth from 2010 to 2021, utilizing demographic data and the 2020 WUI boundaries by the University of Wisconsin-Madison SILVIS Lab. Employing the Mann-Kendall test, we analyze yearly population trends for each census tract along the CA WUI and assess their significance. House ownership, affordability, and wildfire risk are examined as potential drivers of this demographic shift. Our findings indicate that 12.7% of CA’s total population now resides in census tracts with significant population increases over the past decade, labeled as ‘high-growth tracts.’ The Bay Area and Southern California, encompassing 76% of all high-growth tracts in CA, witnessed the most substantial population increase along the WUI. Notably, Riverside County stands out with 29.2% of its residents (approximately 717,000 residents) located in high-growth tracts, exemplifying a significant population surge within CA’s WUI. Our analysis identifies a significant relationship between population increase in the WUI, house ownership, and affordability, where lower-priced homes come at the expense of heightened wildfire risk. However, the impact of house affordability on population growth within the WUI varies by region, playing a more prominent role in explaining population proportions in Southern California’s WUI, while in the universally low-affordability Bay Area, other motivations may drive residents to live within the WUI. Given the rapid growth and insufficient consideration of wildfire risk in the WUI, policymakers must take prompt action, ensuring adequate infrastructure and resources as more individuals relocate to areas with heightened wildfire risk.
Introduction
Authors: Armstrong Chris
Published: February 2024

The world is in the midst of a biodiversity crisis, which existing conservation policies have failed to arrest. Policy makers, academics, and the general public are coming to recognize that much more ambitious conservation policies are in order. However, biodiversity conservation raises major issues of global justice—even if the connection between conservation and global justice is too seldom made. The lion’s share of conservation funding is spent in the global North, even though most biodiversity exists in the global South, and even though local people can often scarcely afford to make sacrifices in the interests of biodiversity conservation. Many responses to the biodiversity crisis threaten to exacerbate existing global injustices, to lock people into poverty, and to exploit the world’s poor. At the extreme, policies aimed at protecting biodiversity have also been associated with exclusion, dispossession, and violence. This book grapples with the challenge of how biodiversity might be conserved without producing global injustice. It distinguishes policies likely to exacerbate global injustice, and policies that promise to reduce it. The struggle to formulate and implement just conservation policies is vital to our planet’s future.
Watchmen over the Apocalyptic Ninth Century
Authors: Gabriele Matthew
Published: February 2024

This chapter slowly moves into the ninth century. In early medieval Europe, authors understood the Augustinian stasis but began to look for signs that God was moving sacred history along. The development of the Franks’ idea of themselves as a new chosen people was the key that unlocked this mystery. The pattern played itself out. The new kingdom of Israel rose, then splintered and fell, just as the old one had. New exegetes such as Hrabanus Maurus and Haimo of Auxerre became new watchmen on the walls, new prophets, calling the sinful Franks back to the Lord.
Franz Boas and the Primacy of Form
Authors: Nanay Bence
Published: February 2024

There is systematic epistemic asymmetry between different centers of art production: we know far more about some (e.g. fifteenth-century Italian paintings) than about others (e.g. fifteenth-century Inca textiles). As long as we are focusing on the social context of the artworks or the artist’s intention, this epistemic asymmetry remains, given that we have vastly more information about the social context of the artworks or the artist’s intention when it comes to ‘Western’ art—again, because of the historically contingent differences in record-keeping and the survival rate of such records. If we want to overcome the epistemic asymmetry between ‘Western’ and ‘Non-Western’ art, we need to look elsewhere. I will argue, using Franz Boas’s work, that we should look for formal features. In order to avoid the epistemic asymmetry that follows from the historically contingent fact that we have more information about some cultures than about others, we need to start our analysis with formal categories.
Effects of rhythm-control and rate-control strategies on cognitive function and dementia in atrial fibrillation: a systematic review and meta-analysis
Authors: Guo Jiahuan , Liu Yanfang , Jia Jiaokun , Lu Jingjing , Wang Dandan , Zhang Jia , Ding Jian , Zhao Xingquan
Published: February 2024

Background

Growing evidence suggests that atrial fibrillation (AF) is an independent risk factor for cognitive impairment and dementia, even in the absence of thromboembolic events and stroke. Whether rhythm-control therapy can protect cognitive function remains unclear. We aimed to evaluate the efficacy of rhythm-control strategies in patients with AF regarding cognitive function and dementia risk.

Methods

We systematically searched the PubMed, Embase and Cochrane Library databases for randomised clinical trials, cohort and case–control studies evaluating the associations between rhythm-control strategies and cognitive function outcomes up to May 2023. We assessed the risk of bias using the ROBINS-I and the Cochrane risk-of-bias tool. Both fixed- and random-effects models were used to create summary estimates of risk.

Results

We included a total of 14 studies involving 193,830 AF patients. In the pooled analysis, compared with rate-control, rhythm-control therapy was significantly associated with a lower risk of future dementia (hazard ratio (HR) 0.74; 95% confidence interval (CI) 0.62–0.89; I2 = 62%). Among the rhythm-control strategies, AF ablation is a promising treatment that was related to significantly lower risks of overall dementia (HR 0.62; 95% CI 0.56–0.68; I2 = 42%), Alzheimer’s disease (HR 0.78; 95% CI 0.66–0.92; I2 = 0%) and vascular dementia (HR 0.58; 95% CI 0.42–0.80; I2 = 31%). Pooled results also showed that compared with patients without ablation, those who underwent AF ablation had significantly greater improvement in cognitive score (standardized mean difference (SMD) 0.85; 95% CI 0.30–1.40; P = 0.005; I2 = 76%).

Conclusions

Rhythm-control strategies, especially ablation, are effective in protecting cognitive function, reducing dementia risk and thus improving quality of life in AF patients.
Core requirements of frailty screening in the emergency department: an international Delphi consensus study
Authors: Moloney Elizabeth , O’Donovan Mark R , Carpenter Christopher R , Salvi Fabio , Dent Elsa , Mooijaart Simon , Hoogendijk Emiel O , Woo Jean , Morley John , Hubbard Ruth E , Cesari Matteo , Ahern Emer , Romero-Ortuno Roman , Mcnamara Rosa , O’Keefe Anne , Healy Ann , Heeren Pieter , Mcloughlin Darren , Deasy Conor , Martin Louise , Brousseau Audrey Anne , Sezgin Duygu , Bernard Paul , Mcloughlin Kara , Sri-On Jiraporn , Melady Don , Edge Lucinda , O’Shaughnessy Ide , Van Damme Jill , Cardona Magnolia , Kirby Jennifer , Southerland Lauren , Costa Andrew , Sinclair Douglas , Maxwell Cathy , Doyle Marie , Lewis Ebony , Corcoran Grace , Eagles Debra , Dockery Frances , Conroy Simon , Timmons Suzanne , O’Caoimh Rónán
Published: February 2024

Introduction

Frailty is associated with adverse outcomes among patients attending emergency departments (EDs). While multiple frailty screens are available, little is known about which variables are important to incorporate and how best to facilitate accurate, yet prompt ED screening. To understand the core requirements of frailty screening in ED, we conducted an international, modified, electronic two-round Delphi consensus study.

Methods

A two-round electronic Delphi involving 37 participants from 10 countries was undertaken. Statements were generated from a prior systematic review examining frailty screening instruments in ED (logistic, psychometric and clinimetric properties). Reflexive thematic analysis generated a list of 56 statements for Round 1 (August–September 2021). Four main themes identified were: (i) principles of frailty screening, (ii) practicalities and logistics, (iii) frailty domains and (iv) frailty risk factors.

Results

In Round 1, 13/56 statements (23%) were accepted. Following feedback, 22 new statements were created and 35 were re-circulated in Round 2 (October 2021). Of these, 19 (54%) were finally accepted. It was agreed that ideal frailty screens should be short (<5 min), multidimensional and well-calibrated across the spectrum of frailty, reflecting baseline status 2–4 weeks before presentation. Screening should ideally be routine, prompt (<4 h after arrival) and completed at first contact in ED. Functional ability, mobility, cognition, medication use and social factors were identified as the most important variables to include.

Conclusions

Although a clear consensus was reached on important requirements of frailty screening in ED, and variables to include in an ideal screen, more research is required to operationalise screening in clinical practice.
Multicolor flow cytometric immunophenotyping is highly sensitive and specific in identifying aberrant mast cells in the diagnostic workup of systemic mastocytosis
Authors: Nwogbo Okechukwu Valentine , Fang Hong , Wang Wei , Xu Jie , Miranda Roberto N , Bose Prithviraj , Ok Chi Young , Jorgensen Jeffrey L , Medeiros L Jeffrey , Wang Sa A
Published: February 2024

Objectives

Flow cytometric immunophenotyping (FCI) is a fast and sensitive method for characterizing hematolymphoid neoplasms. It is not widely used in the workup of systemic mastocytosis (SM), in part because of the technical challenges and in part because the utility of FCI in assessing mast cells is not well understood. The objectives of this study were to assess the diagnostic utility of FCI in establishing a diagnosis of SM and distinguishing SM from nonneoplastic mast cells and to examine the immunophenotypic findings among SM subtypes.

Methods

We performed FCI on bone marrow samples suspicious for SM using a panel consisting of CD2, CD25, CD30, CD45, CD117, and HLA-DR.

Results

The cohort included 88 SM cases: 67 without an associated hematologic neoplasm (AHN) (PureSM) and 21 with an AHN (SM-AHN). We also assessed 40 normal/reactive controls. Overall, FCI was adequate for interpretation in 87 of 88 (99%) cases and detected at least 1 immunophenotypic aberrancy in 100% of SM cases. CD2, CD25, and CD30 were positive in 78%, 98%, and 90% of SM cases vs 0%, 13%, and 13% of cases with normal/reactive mast cells (P < .0001 for all). Two or 3 abnormalities were observed in 92% of SM cases but not in normal/reactive mast cells. Among SM cases, SM-AHN showed statistically significant less CD2 (38% vs 91%, P < .0001) and less co-expression of all 3 aberrant markers (CD2, CD25, and CD30 positive in 38% vs 86% of cases; P < .0001) than PureSM. Immunohistochemical analysis showed consistently weaker or focal expression of CD2, CD25, and CD30 than FCI, with CD2 and CD30 being falsely negative in 40% and 50% cases, respectively. A KIT D816V mutation was detected in 67% of PureSM cases and 76% of SM-AHN cases.

Conclusions

Flow cytometric immunophenotyping is a quick, sensitive, high-yield tool for evaluating the immunophenotype of mast cells. An abnormal FCI finding should prompt careful histologic evaluation and sensitive KIT D816V mutation testing to address the possibility of SM. CD2, CD25, and CD30 are important markers for the detection of immunophenotypic aberrancy of mast cells, and their frequencies of aberrancy differ across SM subtypes.
Real-world utilization of ceftazidime/avibactam among inpatients in the national Veterans Affairs Healthcare System
Authors: Caffrey Aisling R , Appaneal Haley J , Lopes Vrishali V , Riccobene Todd A , LaPlante Kerry L
Published: February 2024

Purpose

Multidrug-resistant (MDR) infections are challenging to treat due to underlying patient conditions, pathogen characteristics, and high antibiotic resistance rates. As newer antibiotic therapies come to market, limited data exist about their real-world utilization.

Methods

This was a national retrospective cohort study of ceftazidime/avibactam (approved in 2015) utilization among inpatients from the Veterans Affairs (VA) Healthcare System, from 2015 through 2021. Joinpoint regression was used to estimate time trends in utilization.

Results

Ceftazidime/avibactam use increased by 52.3% each year (days of therapy per 1,000 bed days; 95% confidence interval, 12.4%-106.4%). We identified 1,048 unique predominantly male (98.3%) and white (66.2%; Black, 27.7%) patients treated with ceftazidime/avibactam, with a mean (SD) age of 71.5 (11.9) years. The most commonly isolated organisms were Pseudomonas aeruginosa (36.3%; carbapenem resistant, 80.6%; MDR, 65.0%) and Klebsiella species (34.1%; carbapenem resistant, 78.4%; extended-spectrum cephalosporin resistant, 90.7%). Common comorbid conditions included hypertension (74.8%), nervous system disorders (60.2%), diabetes mellitus (48.7%), and cancer (45.1%). Median time to ceftazidime/avibactam initiation from admission was 6 days, with a median of 3 changes in therapy before ceftazidime/avibactam initiation and a subsequent median length of inpatient stay of 14 days (median of 8 days of ceftazidime/avibactam therapy). Treatment heterogeneity was high, both before ceftazidime/avibactam initiation (89.6%) and during ceftazidime/avibactam treatment (85.6%), and common concomitant antibiotics included vancomycin (41.4%), meropenem (24.1%), cefepime (15.2%), and piperacillin/tazobactam (15.2%). The inpatient mortality rate was 23.6%, and 20.8% of patients had a subsequent admission with ceftazidime/avibactam treatment.

Conclusion

Utilization of ceftazidime/avibactam increased from 2015 to 2021 in the national VA Healthcare System. Ceftazidime/avibactam was utilized in complex, difficult-to-treat patients, with substantial treatment heterogeneity and variation in the causative organism and culture sites.
Key considerations in navigating ticagrelor’s reported effect on heparin-induced thrombocytopenia functional assays in a landscape of limited data
Authors: Salman Genene , Johannesmeyer Herman J , Breen Martin J
Published: February 2024

Purpose

This article discusses key considerations regarding ticagrelor’s reported effect on heparin-induced thrombocytopenia functional assays, such as literature gaps and possible management strategies.

Limited data indicate that ticagrelor may induce false-negative results in functional assays used in the diagnosis of heparin-induced thrombocytopenia. False-negative functional assays for heparin-induced thrombocytopenia could have catastrophic consequences. The manufacturer labeling of ticagrelor now includes a warning for this potential drug-laboratory interaction. This article suggests areas that would benefit from further research and strategies in navigating this possible interaction.

Conclusion

Clinicians should exercise caution when evaluating functional assays for heparin-induced thrombocytopenia in patients receiving ticagrelor. This article offers suggestions for future areas of research and potential management strategies.