bluuebunny/crossref_metadata_2025 huggingface dataset:
Sky Wave Propagation at Medium and High Frequencies
Authors: Davies Kenneth
Published: November 2024

In this article, we shall discuss the following topics: 1. Basic physical properties of sky wave propagation (namely, refraction, reflection, penetration, and absorption) 2. relationships between vertical propagation and oblique propagation 3. ionospheric models 4. characteristics of medium frequencies 5. characteristics of high frequencies 6. prediction programs for ionospheric sky wave performance 7. real‐time channel evaluation
Microwave Superconductor Devices
Authors: Sans Carles , Tzuzuki Genichi
Published: November 2024

Several superconductor device applications in the microwave area are very briefly discussed in the introduction. After that, the article focuses mostly on superconducting filters since it seems that the application that can grow first into commercial success is also the application that generates more interest. First, the basic categories of response used for superconductor filters are discussed. One of them, the quasielliptic response, is preferred for real applications because it provides better cutoff performance. However, filter synthesis and realization of this response is not as straightforward as the Chebyshev response. The synthesis of quasielliptic responses can be done by the cross‐coupling technique, one of the cutting‐edge topics in the microwave filter field.

Superconducting technology has opened new horizons in the microwave filter field because superconductors can realize filtering responses that are not realizable with other technologies. Superconductor technology allows very compact planar‐type filter circuits with lumped‐element or distributed structures with very high rejection performance. Many different designs and topologies of superconductor filters have been reported in technical journals and international conferences since the 1990s and to the present, but only several of those can be introduced here in the limited number of pages.

Finally, the application of superconductor filters in cellular networks in a form of cryogenic front‐end receivers is discussed. Various different technologies and their integration procedures are considered, such as low‐noise amplifiers, cryogenics, vacuum mechanics, and electronics. Reliability is one of the most important issues in the real world for these applications. Field test results of superconductor filter front‐end systems for TDMA and CDM a applications are also discussed.
Superconducting Cavity Resonators
Authors: Padamsee Hasan
Published: November 2024

A key component of the modern particle accelerator is the device that imparts energy to the charged particles. This is an electromagnetic radio frequency (RF) cavity resonating at microwave frequencies typically between 50MHz and 3000 MHz. Superconducting cavities economically provide high CW operating fields. Another benefit is that superconducting cavities can be designed to have a large beam aperture that reduces the beam cavity interactions, allowing higher beam quality and higher beam current. There are two distinct types of superconducting cavities, depending on the velocity of the particles. The first category is for accelerating charged particles that move at nearly the speed of light, such as electrons in a high‐energy linear accelerator [e.g., at TJNAF at Jefferson Lab in Newport News, VA] or a storage ring [e.g., LEP at CERN in Switzerland]. The second type is for particles that move at a small fraction (e.g., 0.01 to 0.3) of the speed of light, such as the heavy ions emerging from a dc highvoltage Van de Graaff accelerator.
Amplitude Shift Keying
Authors: Xiong Fuqin
Published: November 2024

Amplitude shift keying (ASK) is one of the earliest and simplest digital modulations used in telecommunications. The simplest form of ASK is the
ON
–
OFF
keying (OOK). To improve bandwidth efficiency,
M
‐ary ASK (MASK) must be used. MASK can be coherently demodulated and noncoherently demodulated, and the former has a lower bit error probability but a more complex demodulator. The signal expression, power spectral density, block diagrams of modulators and demodulators (coherent and noncoherent), and bit error rate, are described in detail for each ASK scheme. Comparisons are made between various ASK schemes and between coherent MASK and the popular MPSK (
M
‐ary phase shift keying). Advanced ASK‐based modulation schemes, namely, QAM (quadrature amplitude modulation) and coherent and noncoherent ASK‐OFDM (orthogonal frequency‐division multiplexing) are also briefly described.
Combline Filters
Authors: Wang Chi
Published: November 2024

The combline filter, which was first introduced by Matthaei in 1963, is one of the most commonly used bandpass filters in many communication systems and other microwave applications. With modern filter synthesis theory, combline filters having elliptic function frequency responses can be realized by using the nonadjacent couplings. In this article, the lumped‐element lowpass filter prototype is first presented. The equations for conversion between the lowpass prototypegvalues and the impedance/admittance inverters or coupling matrix elements are given. Matthaei's approximated design equations and procedures using Getsinger's design data for rectangular bars, and Cristal's design curves for cylindrical rods are described for design of direct‐coupled combline filters with narrow to moderate bandwidth. A compact tapped‐line input/output coupling configuration is addressed. The general filter topologies are then discussed. The commonly used cascaded triplet and cascaded quadruplet sections for creating more complicated filter structures are presented. Typical combline applications, including multiplexers, dielectric‐filled miniature combline filters, and linear phase or delay filters are presented.
Antenna Arrays for Mobile Communications
Authors: Paulraj Arogyaswami , Gesbert David , Papadias Constantinos
Published: November 2024

Smart antennas constitute a promising but still emerging technology. Spacetime processing algorithms provide powerful tools to enhance the overall performance of wireless cellular networks. Improvements, typically by a factor of 2 in cell coverage or capacity, are shown to be possible according to results from field deployments using simple beamforming. Greater improvements can be obtained from some of the more advanced spacetime processing solutions described in this article.
Pulse Compression
Authors: Biegert Jens , Diels Jean-Claude
Published: November 2024

Three‐wave interaction in a nonlinear medium can be used to efficiently compress transform‐limited laser pulses with the additional option of shifting the center light frequency.

After introducing the general mechanism together with a simple numerical model, we derive a more extensive and complete numerical model to study pulse compression of long (ps) and ultrashort (fs) pulses. A comparison between theory and experiment is given, and limitations of the models are established.
Low Temperature Co‐Fired Ceramic (LTCC) Technology in RF and Microwave Engineering
Authors: Wu Ke-Li
Published: November 2024

This article outlines the low‐temperature cofired ceramic (LTCC) technology, from its historic evolvement to the basics of dielectric material properties and manufacturing process with emphasis on the design concept of multilayer LTCC RF and microwave embedded passive devices and modules. A detailed table containing most of commonly seen passive components is provided with layouts of their high‐frequency circuit models (Table 4 in the article).
Printed Inductors
Authors: Ooi Ban-Leong , Xu Dao-Xian
Published: November 2024

A new efficient method for calculating the inductance value of a spiral inductor with special emphasis on the nonuniform current distribution on the metallic trace is described. Based on the partial inductance method, a unified approach for modeling the eddy current and skin depth of spiral inductor has been presented. Our proposed method is validated with experimental results, and good agreement has been obtained.
Electromagnetics, Time‐Domain
Authors: Bushyager Nathan A. , Tentzeris Manos M.
Published: November 2024

In this article, various time‐domain electromagnetic simulation methods, including the finite‐difference time‐domain (FDTD), transmission‐line matrix (TLM), finite‐element time‐domain (FETD), and multiresolution time‐domain (MRTD) techniques are discussed in detail along with grid optimization approaches. In addition, conformal meshing techniques, specifically finite‐volume time‐domain (FVTD) and generalized Yee FDTD methods are briefly descirbed. Also included is a discussion of code parallelization, grid excitation, absorbing boundary conditions, antenna modeling, and methods that can be used to deriveSparameters from time‐domain output data.
Heterojunction Bipolar Transistor
Authors: Prasad Jayasimha
Published: November 2024

The major advances in heterojunction bipolar transistor (HBT) technology since the mid‐1980s is covered in this article. The cutoff frequency (fT) and the maximum oscillation frequency (fmax) have reached record highs. Indium phosphide (InP) HBTs have shown (fT) and (fmax) in excess of 450 GHz and gate delays of 1.95 ps. Silicon–germanium (SiGe) HBTs have demonstrated 350 GHz (fT) and gate delays of 3.6 ps. The improved performance of the devices has resulted in impressive circuit results. Static frequency dividers operating at 152 GHz has been reported in InP HBT technology. SiGe HBT technology has demonstrated dynamic frequency dividers running at 110 GHz. Multiplexer/demultiplexer (MUX/DMUX) circuits operating at 40 Gbps (gigabits per second) were demonstrated with InP HBTs. On the other hand, 50‐Gbps 4–1 MUX/DMUX circuits have been shown with SiGe HBTs.
PIN Diodes
Authors: Fathy Aly E. , Rosen Arye
Published: November 2024

A PIN diode is a semiconductor device that operates at RF and microwave frequencies as a variable resistor in the forward direction.

The PIN diode is useful for leveling, limiting, and amplitude modulating an RF signal, when the control current is varied continuously. However, the device can be used for pulse modulating, attenuating, and phase shifting of an RF signal if the control current is turned ON or OFF, or in discrete steps. In addition, the PINs small size, weight, high switching speed, and minimized parasitic elements make it ideally suited for miniature, broadband RF signal applications.
Schottky Barriers
Authors: Ashok S.
Published: November 2024

The Schottky barrier, one of the earliest and simplest semiconductor interfaces studied, consists of a metal in contact with a semiconductor.

The silicide Schottky barriers are of interest from both fundamental and practical viewpoints, as the MS interface here is buried inside the semiconductor bulk, thus obviating the deleterious influence of surface oxides and other contamination.

We will consider here two basic models, the earlier one due to Schottky and the later one inspired by Bardeen's postulation of the surface states.
Missile Guidance
Authors: Rodriguez Armando A.
Published: November 2024

Missile guidance addresses the problem of steering, or guiding, a missile to a target on the basis of a priori known target coordinate information and/or real‐time target measurements obtained from onboard or external sensors.
Electromagnetic Field Measurement
Authors: Kanda Motohisa
Published: November 2024

Various electromagnetic field sensors for measuring radiofrequency (RF) electric and magnetic fields are discussed.

Throughout the discussion, the interplay between measured quantities and predicted (modeled) quantities is emphasized. The ability of measurements and the restrictions imposed by rigorous theoretical analysis of given models are discussed for the frequencies from 10 kHz to 40GHz and upward.
Magnetic Microwave Devices
Authors: How Hoton
Published: November 2024

Magnetic microwave devices discussed in this article include ferrite junction devices, lumped‐element circulators, nonreciprocal resonators, YIG film and MSW devices, magnetooptic devices, absorbing/antireflection layers, and nonlinear magnetic devices. A general theoretical background underlying the physics for the operation of a ferrite microwave device is first reviewed. Discussions include the derivation of the Polder permeability tensor, the effective fields associated with electron spin motion, the general dispersion spectrum and plane‐wave solutions for electromagnetic wave propagation in a bulk magnetic medium, MSW (magnetostatic waves) admitted by the geometry of a yttrium iron garnet (YIG) film, and the nonlinear instabilities for spin waves occurring at high power, including their routes to chaos. Ferrite junction devices including circulators and isolators are discussed in terms of their bandwidth operation, size reduction, power handling, and other novel issues such as intermodulation noise. The operation of lumped‐element circulators is introduced and the interport impedances outlined. The effective field associated with a magnetic easy plane is defined from an operation point of view. A ferrite nonreciprocal resonator can be used as a phase shifter whose operation is independent of the derived phase shift angles. YIG film devices incorporating magnetostatic waves are introduced, including delay lines, filters, directional couplers, and resonators. Nonlinear magnetic devices are discussed, including frequency‐selective power limiters, signal‐to‐noise enhancers, amplitude correctors, and ferrimagnetic echoing devices. Magnetic solitons include Bloch domain wall solitions and microwave magnetic envelope solitons. Finally, magnetooptic Kerr and Faraday effects and the operation of magnetooptic Bragg diffraction devices are discussed, and the design of microwave absorbing layers and antireflection layers is briefly introduced.
Bandstop Filters
Authors: Choi Chiu H.
Published: November 2024

An approach to designing a circuit (a bandstop filter)with a frequency response that satisfies the bandstop requirements is described below. It consists of two steps: the approximation of the requirements by a transfer function and the synthesis of the transfer function. A bandstop filter (also known as
band-reject
,
band-elimination
, or
notch filter
) suppresses a band of frequencies of a signal, leaving intact the low‐ and high‐frequency bands.
Coplanar Stripline (CPS) Components
Authors: Suh Young-Ho
Published: November 2024

Coplanar stripline (CPS) is a balanced uniplanar transmission line, consisting of two metallic conductor strips separated by a certain gap width, on a substrate. Conventional CPS does not provide bottom metallization of the substrate for ground; instead, one of the conductor strips provides electric ground of the other signal strip.

This article investigates (1) CPS transmission‐line characteristics for practical circuit design and analysis using closed‐form equations; (2) CPS circuit components such as resonators, filters, and “tee” junctions; and (3) applications to antennas and wireless power transmission.

Various new CPS resonators are modeled and designed and their performance investigated in terms ofQfactor or bandwidth. As applications of the proposed CPS resonators, new CPS bandpass filters are demonstrated. The design methods of bandpass filters and their lumped‐element equivalent circuits are presented. A simple CPS lowpass filter is developed using interdigital capacitors and a CPS transmission line.

For CPS component measurements, two types of broadband CPS‐to‐microstrip transition are introduced. Printed dipole antenna feeding can also be easily implemented using this transition.

A novel CPS tee junction using coupled CPS (CCPS) is introduced. As an application of CPS tee junction, a twin‐dipole antenna fed by microstrip‐to‐CPS tee junction is presented at Ka band. A 1×8 printed dipole phased array is developed with the twin‐dipole antenna.

Finally, as a circuit application of CPS, a dual‐frequency rectenna is developed at 2.45 and 5.8 GHz. For dual‐frequency rectenna components, a dual‐frequency antenna, CPS lowpass filter, and CPS bandstop filters are developed. To achieve high RF ‐to‐DC conversion efficiencies at both frequencies, diode analyses are performed for frequency‐insensitive high conversion efficiency.
Directional Couplers
Authors: Rozzi Tullio , Morini Antonio
Published: November 2024

The directional coupler (DC) is the most useful four‐port microwave device. Substantially, it consists of a four‐port device, where a wave entering any port excites two other ports with prescribed amplitudes, whereas the remaining port is isolated. This property makes the DC an essential component when dealing with microwave devices, as it allows to distinguish reflected waves from incident ones. After a definition of the ideal DC, the typical parameters and the electrical characteristics of actual devices are illustrated, then, the main applications are considered and, finally, some common realizations of DC are shown, particularly focusing the attention on different coupling mechanisms and technologies.
Finlines
Authors: Hoefer Wolfgang J. R. , Vahldieck Ruediger
Published: November 2024

Finlines are guiding structures for electromagnetic waves that consist of one or several metallic fins suspended in theEplane of a waveguide enclosure. They are the basic transmission media for the so‐called integratedE‐plane circuit technology.

Finlines are applied predominantly in the frequency range between 10 and 100 GHz; but some applications at frequencies up to 170GHz have been realized. Having losses of typically 0.1 dB per wavelength, finlines are not suitable for long‐distance transmission. However, they excel as a circuit medium for millimeter‐wave components and systems due to their low manufacturing cost, wide single‐mode bandwidth, compatibility with discrete active and passive devices, and suitability for integration with other hybrid circuit techniques as well as with standard rectangular waveguides.
Microwave Parametric Amplifiers
Authors: Faber Marek T.
Published: November 2024

An outline of the development of microwave parametric amplifiers (paramps) is presented as an introduction. The principle of their operation is explained leading to the classification of parametric amplifiers and frequency converters. (Photoparametric amplification is also referenced.) Varactor diodes are briefly presented in order to discuss in greater detail the operation of the most significant type of paramp—the nondegenerate parametric amplifier—including gain, noise, bandwidth, and stability. Degenerate, multiple‐idler and traveling‐wave parametric amplifiers are also discussed. Then the construction of a 3.25‐GHz nondegenerate parametric amplifier is presented as a representative example.
Microwave Solid‐State Devices
Authors: Schreurs Dominique M. M.-P.
Published: November 2024

This article presents an overview of the solid‐state devices that are now being used in telecommunication systems. We discuss several families of microwave and millimeter‐wave diodes and transistors. For each device type, we briefly describe the physical operation, discuss the properties and frequency limitations, and outline the main application areas.
Transmission Lines and Parameters
Authors: Chen Ji , Chen Richard L.
Published: November 2024

Transmission lines are defined as waveguiding structures that can support transverse electromagnetic (TEM) waves or quasi‐TEM waves. This article concentrates on five commonly used transmission‐line structures. The transmission‐line parameters are first introduced in the derivation of the telegrapher's equations by dividing the transmission line into electrically small segments that can be described by the lumped‐element circuit theory. The transmission‐line parameters are then derived from rigorous electromagnetic field analysis. Five commonly used transmission lines—parallel‐plate waveguides, coaxial cables, two‐wire lines, striplines, and microstrip lines—are presented, and the techniques used to extract their corresponding transmission‐line parameters are given. A common integrated circuit (IC)‐level transmission‐line structure is presented, and the challenges in parameter extraction for future micro‐ and nanoscale transmission lines are also discussed.
Waveguide Junctions
Authors: Levy Ralph
Published: November 2024

The properties ofn‐port waveguide junctions are described in fundamental terms, with methods for finding impedance and admittance representations from the scattering matrix, leading to equivalent‐circuit representations. Some of the general properties ofnports are treated, with most examples dealing with three‐ and four‐port junctions. Three‐port networks includeE‐ andH‐plane T junctions andE‐plane bifurcations, and the discussion of four ports includes magic‐Ts and ring hybrids. Emphasis is placed on fundamental properties, the understanding of which is important for future research.
Target Tracking
Authors: Drummond Oliver E.
Published: November 2024

Target tracking design and development is challenging if the measurement density is not sparse. Close targets, clutter , or false signal can cause conditions of dense measurements. The tracking algorithms used for a system need to be selected based on the specifics of the application. This article addresses alternative algorithms for both single and multiple target tracking; tracking using either a single sensor or data from multiple sensors (sensor data fusion); and discusses trade‐offs considerations for selecting appropriate algorithms for a system.
Radiometry
Authors: Glover Ian A.
Published: November 2024

Radiometry is concerned with the measurement, analysis, and interpretation of radiant electromagnetic energy. The simplest and most common measurement, made using an instrument called aradiometer, is of received electromagnetic power in a given frequency band. Some instruments, however, analyze the received energys spectral distribution (spectroradiometers), its polarization (polarimeters), or its angular distribution in space (imaging radiometers). The usual objective of radiometric measurements is the inference from them of the physical and/or chemical state of the material from, or through which, the received electromagnetic energy has been emitted, reflected, or transmitted. Radiometry is therefore a branch of remote sensing and could be considered to include radar.
Accelerated Polysulfide Conversion by Rationally Designed NiS2‐CoS2 Heterostructure in Lithium–Sulfur Batteries
Authors: Ye Xing , Wu Fang , Xue Zhiyu , Yuan Haowei , Mei Shijie , Wang Jiacheng , Yang Ruizhe , Wu Xiaomeng , Zhao Xiaoli , Pan Hong , Zhang Qinyong , Xiang Yong , Huang Ming , Li Fei
Published: November 2024

Lithium–sulfur (Li–S) batteries are considered as potential candidates for future‐oriented energy storage systems. However, their practical deployment is hampered by the shuttle effect and the sluggish reaction kinetics of lithium polysulfides (LiPSs). A key strategy to mitigate these challenges is to develop efficient heterojunction catalysts to enhance reaction kinetics and suppress the shuttle effect. In this study, a NiS2‐CoS2 heterojunction is introduced to address these challenges with density functional theory (DFT) calculations employed to determine the optimal combination from 5  ×  5 crystal plane configurations. The identified NiS2(210)‐CoS2(200) combination demonstrates excellent anchoring effects and catalytic properties for LiPSs, significantly enhancing rate performance (839.9 mAh g−1 at 2 C and 730.8 mAh g−1 at 3 C) and cycling stability. Furthermore, in situ Raman and X‐ray diffraction (XRD) analyses reveal that the NiS2‐CoS2 heterojunction rapidly catalyzes the conversion of LiPSs, reducing their migration toward the lithium anode and thereby suppressing the shuttle effect. The design strategy for transition metal sulfide heterojunctions offers an efficient approach to accelerating polysulfide conversion kinetics, effectively addressing the limitations of Li–S batteries.
Triboelectric Pulse Promotes Self‐Cleaning, Catalysis of Nano‐Confined Domain Lamellar Membranes for Effective Water Decontamination
Authors: Zhao Changrong , Liu Bin , Chang Haiqing , Xie Fazhi , Wu Ruoxi , Zhou Shiqing , Zhu Xuewu , Liang Heng , Zhu Junyong
Published: November 2024

Triboelectric nanogenerators are promising green electrocatalytic alternative energy sources; however, their low current density renders practical applications challenging. Herein, a self‐generating electricity mode based on a droplet friction strategy that significantly mitigates membrane fouling while facilitating the contact of oxidizing substances and sulfamethoxazole within the nanoconfined spaces of 2D conductive catalytic membranes is proposed, which are elaborately designed via the co‐assembly of CoFeMoOOH and MXene laminates. In the confined domain space of the membrane, triboelectric pulses resulted in a 267% (1800  to 4800 min−1) enhancement of the degradation rate constant of sulfamethoxazole, which is significantly higher than the 17% (0.35  to 0.41 min−1) for the suspension system. In situ filtration and kinetic modeling revealed that the pulsed electrical signal generated by the permeate promoted molecular polarization and longitudinal mass transfer within the confined domain space. The alteration in the adsorption‐desorption behavior of solvent/solute molecules between the confined domain layers leads to the migration of water molecules and pollutants in opposite directions, facilitating positive catalytic reactions and fouling inhibition. The proposed self‐generating pulsed electricity‐assisted nanoconfined catalysis offers a powerful tool for efficiently harnessing environmental micro‐energy for the green upgrading of water treatment processes.
Synergistic Electroconversion of CO2‐to‐n‐Propanol Over Atomically Dispersed Lewis Acid Zr‐Doped Cuδ+ Catalysts
Authors: Zhou Linjiao , Huang Zichao , Guan Chaoqun , Zhang Yingbing , Bai Suxin , Kuang Min , Yang Jianping
Published: November 2024

Electrochemical carbon dioxide reduction to n‐propanol, a high‐energy‐density C3 chemical, presents a promising method for the long‐term storage of renewable electricity. However, the C1‐C2 coupling step, crucial for C3 conversion, suffers from low selectivity and sluggish conversion rate. In this study, a strategy is proposed to regulate the adsorption of C2 active species on Cu by introducing an atomically dispersed Zr, which can effectively enhance the electroreduction of CO2 to n‐propanol. In situ infrared spectroscopy and theoretical studies unveil that the introduce of atomically dispersed Zr modulates the adsorption configuration of *C2 intermediates and strengtnens the binding with *C2 intermediates, thus lowing the energy barrier of the C1–C2 coupling process and accelerating the conversion efficiency. This novel catalyst achieves a n‐propanol Faradaic efficiency of 14.4 ± 0.3% and a high production rate of 70.0 ± 1.0 mA cm−2, comparable to the best reported values of the CO2‐to‐propanol electroconversion. This study highlights the effectiveness of designing synergistic electrocatalysts to boost the production of high‐value energy products, providing a promising path toward achieving carbon neutrality.
Plasma Treatment Induced Charge Transfer for Realization of Negative Differential Transconductance in Van Der Waals Single‐Channel
Authors: Han Kyu Hyun , Kim Seung‐Hwan , Kim Jong‐Hyun , Yu Hyun‐Yong
Published: November 2024

For upcoming AI computing era, the multi‐valued logic (MVL) is promising for processing multiple information with high‐density device. Particularly, the negative differential transconductance (NDT) devices as element of MVL have been needed to overcome complicated heterostructures with multiple stacking process. Herein, the single‐channel device is developed with NDT phenomenon through plasma treatment in van der Waals (vdW) transistor. The O2 plasma treatment formed amorphous oxidation layer capable of charge transfer on vdW materials. Through O2 plasma treatment on single‐channel, the NDT phenomenon is implemented by forming the multiple VTH in single‐channel electrical curve due to charge transfer p‐doping effect. The peak‐to‐valley current ratio (PVCR) of NDT phenomenon is achieved to 102. Furthermore, ternary inverter is demonstrated in single‐channel combined with NDT and load device. Finally, by implementing NDT peak in single‐channel transistor, the complexity and size of MVL circuit is reduced, moving away multiple heterostructure.
U‐Shaped Dimeric Acceptors for Balancing Efficiency and Stability in Organic Solar Cells
Authors: Ding Pengfei , Chen Zhenyu , Yang Daobin , Yu Xueliang , Shi Jingyu , Chen Yiyu , Zhu Jintao , Wu Jie , Cao Xinyue , Xie Lin , Chen Fei , Ge Ziyi
Published: November 2024

Despite significant improvements in power conversion efficiencies (PCEs) of organic solar cells (OSCs), achieving excellent stability remains a great challenge to their commercial feasibility. Here, U‐shaped dimeric acceptors (5‐IDT and 6‐IDT) with different molecular lengths are introduced into the binary OSCs as a third component, respectively. The introduction of the third component effectively reduces the energetic disorder and non‐radiative voltage losses and improves the exciton dissociation and charge transport of the devices. Consequently, the PCEs of the 6‐IDT‐ and 5‐IDT‐treated OSCs are significantly improved to 19.32% and 19.96%, respectively, which is the highest PCE for oligomeric acceptors‐based ternary OSCs to date. Meanwhile, the thermal stability of the treated devices is dramatically improved, with the initial efficiency retention of the 6‐IDT‐ and 5‐IDT‐treated devices increasing from 18% to 32% and 75%, respectively, after 1000 h of thermal stress. This is mainly attributed to the ability of the smaller molecular length of 5‐IDT to stabilize the phase‐separated morphology of the polymeric donor and small molecular acceptor, rather than the high glass transition temperature and low diffusion coefficient.
Carbon Quantum Dots in Biomedical Applications: Advances, Challenges, and Future Prospects
Authors: Pechnikova Nadezhda A. , Domvri Kalliopi , Porpodis Konstantinos , Istomina Maria S. , Iaremenko Aleksandra V. , Yaremenko Alexey V.
Published: November 2024

Carbon quantum dots (CQDs) represent a rapidly emerging class of nanomaterials with significant potential in biomedical applications due to their tunable fluorescence, high biocompatibility, and versatile functionalization. This review focuses on the recent progress in utilizing CQDs for drug delivery, bioimaging, biosensing, and cancer therapy. With their unique optical properties, such as tunable fluorescence, high quantum yield, and photostability, CQDs enable precise bioimaging and sensitive biosensing. Their small size, biocompatibility, and ease of surface functionalization allow for the development of targeted drug delivery systems, enhancing therapeutic precision and minimizing side effects. In cancer therapy, CQDs have shown potential in photodynamic and photothermal treatments by generating reactive oxygen species under light exposure, selectively targeting cancer cells while sparing healthy tissues. Furthermore, CQDs’ ability to penetrate biological barriers including the blood–brain barrier opens new possibilities for delivering therapeutic agents to hard‐to‐reach areas, such as tumors or diseased tissues. However, challenges such as optimizing synthesis, ensuring long‐term stability, and addressing safety concerns in biological environments remain critical hurdles. This review discusses current efforts to overcome these barriers and improve CQD performance in clinical settings, including scalable production methods and enhanced biocompatibility. As research progresses, CQDs are expected to play an important role in improving healthcare by offering more targeted treatment options and contributing to advancements in personalized medicine.
A Novel Mixed Convolution Transformer Model for the Fast and Accurate Diagnosis of Glioma Subtypes
Authors: Nobel S. M. Nuruzzaman , Swapno S. M. Masfequier Rahman , Islam Md Babul , Azad AKM , Alyami Salem A. , Alamin Md , Liò Pietro , Moni Mohammad Ali
Published: November 2024

Glioblastoma is the most common adult brain tumor, significantly impacts disability and mortality. Early and accurate diagnosis of glioma subtypes is essential, but manual categorization is challenging due to their complexity, prompting the need for automated solutions. We developed an innovative mixed convolution‐transformer model to classify glioma subtypes, including astrocytoma, glioblastoma, oligodendroglioma, and normal brain tissue, using whole slide images. The novelty of this model lies in its remarkable efficiency and precise results. Multiple advanced and complex layers are incorporated during its development to enhance its performance, ensuring that it delivers fast and accurate classification results for glioma. This proposed model obtains an overall training accuracy of 97.41%, peaking at 98.12% for validation and 97.35% for testing. Next, our model architecture is independently evaluated by comparing its training performances on the CIFAR‐10 and CIFAR‐100 datasets with the vision transformer and compact convolutional transformer models. Results across various datasets demonstrate that the model consistently outperforms existing models. This performance underscores the effectiveness of our proposed approach in classifying glioma subtypes accurately and efficiently, highlighting its potential impact on healthcare and disability. This system enhances the classification of glioma subtypes and facilitates swift identification, ensuring appropriate and timely treatment.
Model Selection for Ordinary Differential Equations: A Statistical Testing Approach
Authors: Dattner Itai , Gugushvili Shota , Laskorunskyi Oleksandr
Published: November 2024

Ordinary differential equations (ODEs) are foundational tools in modeling intricate dynamics across a gamut of scientific disciplines. Yet, a possibility to represent a single phenomenon through multiple ODE models, driven by different understandings of nuances in internal mechanisms or abstraction levels, presents a model selection challenge. This study introduces a testing‐based approach for ODE model selection amidst statistical noise. Rooted in the model misspecification framework, we adapt classical statistical paradigms (Vuong and Hotelling) to the ODE context, allowing for the comparison and ranking of diverse causal explanations without the constraints of nested models. Our simulation studies numerically investigate the statistical properties of the test, demonstrating its attainment of the nominal size and power across various settings. Real‐world data examples further underscore the algorithm's applicability in practice. To foster accessibility and encourage real‐world applications, we provide a user‐friendly Python implementation of our model selection algorithm, bridging theoretical advancements with hands‐on tools for the scientific community.
Improved Effectiveness of Combined Screening for Multiple Cancers: A Government‐Organized Population‐Based Study in China
Authors: Lu Qian , Liang Di , Shi Jin , Wu Siqi , Du Xinyu , He Yutong
Published: November 2024

Objective

The purpose of this study was to analyze the effectiveness of the Cancer Screening Program in Urban China (CanSPUC) in Hebei Province, 2016–2023.

Methods

A questionnaire for risk factors of lung, breast, upper gastrointestinal, liver, and colorectal cancers was administered to urban residents aged 40–74 years in five cities to assess their cancer risk. High‐risk participants were invited for screening and classified into five groups on the basis of the number of cancer types that were assessed to be high risk. The participation and positive outcome rates were analyzed. The incidence and the mortality of five types of cancer and all‐cause mortality of the screened and nonscreened participants were calculated via inverse probability weighting.

Results

A total of 237,975 eligible participants were enrolled in our study and 118,339 participants (49.94%) were assessed to be at high risk for one or more of the five cancer types. The number of screenings performed was 103,824, with a screening participation rate of 40.49%. Among the 57,315 screening participants, 9077 (15.84%) had positive cancer diagnoses and 871 (1.52%) were diagnosed with suspected cancer. Compared with the participants at high risk for a single cancer type, the participation and positive outcome rate increased by 45% and 71.5% in the participants at high risk for multiple cancer types. Compared with the non‐screened participants, the screened participants had a 27.0% decrease in mortality due to the five types of cancer and a 45.8% decrease in all‐cause mortality.

Conclusion

A combined screening program for multiple cancers could increase participation and positive outcome rates. It could also decrease the five types of cancer mortality and all‐cause mortality. Our findings highlight the effectiveness of combined screening for multiple cancers with limited health care resources, and may provide foundational evidence for the feasibility of conducting combined screening programs.
Ensure your emergency response plans comply with NATA's updated EAP position statement
Authors: Neal Timothy
Published: November 2024

Having the right plans in place can help your athletics department respond promptly and effectively to emergencies while limiting liability and preventing those emergencies from turning into out‐of‐control crises. To help college athletics departments prepare for any emergency, the National Athletic Trainers’ Association released new guidance earlier this year, the 2024 “National Athletic Trainers’ Association Position Statement: Emergency Action Plan Development and Implementation in Sport.” This updated plan outlines substantial advancements from the 2002 “National Athletic Trainers’ Association Position Statement: Emergency Planning in Athletics.” The emergency action plan is a written document that details the steps for athletic trainers, team physicians, and other health care professionals and stakeholders to take in order to ensure they’re prepared for on‐site emergency response to catastrophic or potentially catastrophic injuries in athletics‐related settings. The EAP is designed to facilitate emergency preparedness via an efficient and coordinated emergency response, and shouldn’t be mistaken for being the same as policies and procedures. Instead, an outgrowth of the EAP is a protocol in the form of a document that provides guidance for steps, decisions, and actions in sports medicine.
School‐based mental health curriculum nationally available at no cost: Adolescent Depression Awareness Program (ADAP)
Authors: Espinoza Candice S. , Swartz Karen L.
Published: November 2024

According to Substance Abuse and Mental Health Services Administration (SAMHSA), as of 2021, an estimated 5.0 million (20.1%) adolescents in the United States aged 12 to 17 have had at least one major depressive episode with approximately 3.7 million having significant impairment (defined as difficulty doing well at work or school, issues having a social life, problems doing chores at home, and/or struggles getting along with family). The prevalence of having a major depressive episode was nearly three times higher among adolescent females when compared to males and was highest among adolescents reporting two or more races.
Decoding youth substance use: Insights and strategies
Authors: Gomes Nicole , Paccione‐Dyszlewski Margaret
Published: November 2024

Substance use among youth aged 12 to 17 presents a major public health concern in the United States with statistics revealing that one in eight youths have engaged in illicit substance misuse within the past year (National Center for Drug Abuse Statistics, 2023). The long‐term consequences of youth substance use include complicated medical issues, mental health disorders, impaired brain development, social and behavioral issues, addiction and dependence problems, and financial and legal consequences. By comprehending, preventing, and addressing factors of youth substance use, parents, educators, and healthcare providers can protect the well‐being of young individuals, their families, and the community.
Parents now more than ever need to help keep kids safe
Authors: Knopf Alison
Published: November 2024

The outgoing president of the American Academy of Pediatrics listed the many ways in which the organization has protected children over the past year, but parents clearly need to be there as well. Keeping health insurance and access to mental health care, promoting vaccine confidence, keeping children safe online, challenging bans on gender‐affirming care and reproductive health services are just some of the important protections for children.
Integrated Assessment of Coronary Physiology Based on Coronary Angiography in Heart Transplant Patients
Authors: Fezzi Simone , Pesarini Gabriele , Guerrieri Ludovica , Urbani Allegra , Bottardi Andrea , Tavella Domenico , Wijns William , Tu Shengxian , Scarsini Roberto , Ribichini Flavio
Published: November 2024

Background

Early detection of cardiac allograft vasculopathy after heart transplant (HTx) with invasive coronary angiography is challenging.

Aims

The study aimed to determine if computational techniques able to assess epicardial lesions, by means of Murray's law‐based quantitative flow ratio (μFR), and microvascular physiology, by means of angiography microvascular resistance (AMR), enhance risk stratification in HTx patients with nonsignificant coronary artery disease.

Methods

The cohort consisted of 86 consecutive HTx patients (200 epicardial vessels) with stenosis < 50% at baseline. μFR ≤ 0.80 indicated coronary ischemia, while AMR ≥ 2.5 suggested microvascular dysfunction. Clinical events were assessed over a median follow‐up of 43 months, focusing on the relationship between μFR and target vessel failure (TVF), and between AMR and heart failure (HF) hospitalizations.

Results

At baseline, mean μFR was 0.94 ± 0.08, with eight vessels (4.0%) disclosing flow‐limiting lesions, while AMR was 2.4 ± 0.7, with 80 vessels/40 patients (40.0%/46.5%) having microvascular dysfunction. TVF‐related segments were associated with lower mean μFR values (0.89 ± 0.14 vs. 0.95 ± 0.05; p < 0.007) compared TVF‐free segments. At the receiver operating characteristic curve a μFR ≤ 0.93 demonstrated an area under the curve of 0.632 (95% CI: 0.562–0.699) in predicting TVF occurrence, showing an accuracy of 76.0%, a sensitivity of 46.9%, a specificity of 81.6%, a negative predictive value of 89.0%, and a positive predictive value of 32.6%. μFR ≤ 0.93 showed a significant interaction with TVF occurrence at 43 months (32.6% vs. 11.0%; HR: 2.96; 95% CI: 1.26–6.96; p = 0.013). Microvascular dysfunction showed a significant interaction with HF hospitalizations occurence (AMR: 2.8 ± 4.4 vs. 2.4 ± 4.5; p = 0.001; CMD: 27.5% vs. 4.3%; HR: 7.36; 95% CI: 2.45–22.07; p = 0.002).

Conclusions

Angiography‐derived epicardial and microvascular physiology computation may improve risk stratification of heart transplanted patients.
Drivers of Anuran Assemblage Structure in a Subtropical Montane Region
Authors: Bassetto Kauan , Carvalho‐Rocha Vítor , Peres Carlos A. , Neckel‐Oliveira Selvino
Published: November 2024

Elevation gradients provide excellent semi‐experimental conditions to investigate how the spatial distribution of biodiversity is shaped by the environment. Here, we investigate how temperature, productivity, and elevation are related to the diversity of anuran assemblages in a montane region of the southern Brazilian Atlantic Forest. We sampled 20 half‐hectare plots between 2020 and 2021, distributed along a sharp elevation gradient. Anuran species richness and abundance decreased with increasing elevation. We show a positive relationship between ambient temperature and frog species richness and abundance, highlighting the importance of temperature in shaping assemblages along the elevation gradient. In contrast, productivity did not affect species richness and abundance, suggesting that available energy via resources does not limit local frog diversity. We further observed marked differences in the composition of anuran assemblages between low and high elevation areas, which were related to temperature. Beta diversity is mainly driven by species replacements among assemblages, which were likely related to environmental conditions. These findings highlight the importance of incorporating protected areas that encompass the entire range of elevations to capture the full complement of landscape‐scale diversity. This is crucial as species showed limited distributions, and the marked effects of temperature should be explicitly considered under future scenarios of elevated upslope warming.
Governing of Melt Pool Solidification Parameters and Microstructure Evolution Indicator During SLM‐Ti6Al4V Alloy Through Parametric Sweep Optimization
Authors: Weldeanenia Kidu Gebrecherkos , Kassegne Samuel Kinde , Ramulu Perumalla Janaki
Published: November 2024

Selective laser melting (SLM) process offers a versatile additive manufacturing technology. However, the wide range of process parameters and complex thermophysical phenomenon necessitate optimization of process parameters for obtaining a high‐quality finished product. The optimization of process parameters through experiment is expensive and time‐consuming. On the other hand, computational approaches offer a fast and economical way to predict the contributions of process parameters. In this article, therefore, a multiphysics finite‐element model and phase‐filed model of solidification process were used to investigate the effects of process parameters on the melt pool solidification parameters and microstructure evolution of SLM‐Ti6Al4V process. Simulations were performed using the single‐level setup method followed by a parametric sweep optimization (PSO) approach that helped identify the best‐suited process parameters. Through the PSO, reductions in temperature gradient by 9.7% and 13.7%, and cooling rate by 23.6% and 14.3% were found at a fixed laser scan speed and laser power, respectively. The associated solidification morphology factor was found to be 5.8 × 105 Ks/m2. In addition, the primary dendrite arm spacing (PDAS) was found to be at 3.6% and 6.8% increments at a fixed laser speed and laser power, respectively. Finally, optimal results of the solidification parameters were compared with the existing data to validate the approach. The simulation results have been shown that reduction in the temperature gradient by 28.5%, cooling rate by 48.6%, and solidification morphology factor by 3.3% tend to minimize fluctuation of melt pool. The comparisons have also shown that the PSO approach is effective and accurate for predicting the solidification behaviors of SLM‐Ti6Al4V process.