bluuebunny/crossref_metadata_2025_split huggingface dataset:
β-Blocker Use and Delayed Onset and Progression of Huntington Disease
Authors: Schultz Jordan L. , Ogilvie Amy C. , Harshman Lyndsay A. , Nopoulos Peg C. 
Published: December 2024

ImportanceHuntington disease (HD) is characterized by motor, cognitive, and psychiatric decline. β-Blockers may play a therapeutic role by decreasing enhanced sympathetic tone in HD.ObjectiveTo evaluate the impact of β-blockers on the timing of motor diagnosis onset and progression of HD symptoms.Design, Setting, and ParticipantsThis observational, longitudinal multicenter study used the Enroll-HD platform database (initiated September 2011 to present), including propensity score–matched cohorts of patients with premanifest HD (preHD) and early motor-manifest HD (mmHD) who were either users or nonusers of β-blockers. Participants included patients with genetically confirmed preHD (n = 4683 eligible participants) or mmHD (n = 3024 eligible participants) who were taking a β-blocker and were matched to similar non–β-blocker users.ExposureUninterrupted use of a β-blocker for more than 1 year.Main Outcomes and MeasuresFor PreHD: risk of receiving a motor diagnosis of HD over time. For mmHD: progression rate of total motor score, total functional capacity score, and the symbol digit modalities test. Post hoc analyses were performed to test additional clarifying hypotheses after the primary analyses were completed.ResultsThis study included 174 preHD β-blocker users (59 males; 115 females) with a mean age of 46.4 (SD, 13.1) years and a mean cytosine-adenine guanine repeat length of 41.1 (SD, 2.4) who were well matched to 174 preHD non–β-blocker users. The preHD β-blocker users showed a statistically significant reduction in the annualized hazard of receiving a motor diagnosis compared with nonusers (n = 174) (hazard ratio, 0.66; 95% CI, 0.46-0.94; P = .02). There were 149 mmHD β-blocker users (86 males; 60 females) with a mean age of 58.9 (SD, 11.3) years and a mean cytosine-adenine guanine repeat length of 42.0 (SD, 2.3) matched to 149 mmHD non–β-blocker users. The β-blocker users had a slower mean annualized worsening in total motor score (mean difference [MD], −0.45; 95% CI, −0.85 to −0.06; q = 0.025), total functional capacity score (MD, 0.10; 95% CI, 0.02-0.18; q = 0.025), and symbol digit modalities test (MD, 0.33; 95% CI, 0.10-0.56; q = 0.017) compared with matched nonusers.Conclusions and RelevanceIn this study, β-blocker use was associated with delayed motor onset in preHD and reduced the rate of worsening of symptoms in mmHD. These findings demonstrated that β-blockers may have a therapeutic role in HD but further studies are required.
Adaptive Antenna Arrays
Authors: Sun Chen , Karmakar Nemai C. , Zomorodi Mohammad , Nguyen Dong H. 
Published: December 2024

AbstractAdaptive array antennas play an important role in wireless communications systems. The article begins with a brief introduction to the evolution of wireless communications systems and demands for adaptive array antennas. After that, the current and future applications of adaptive array antennas in wireless communications systems are described. Next, the structures and implementations of the adaptive array antenna systems, including switched‐beam antennas, phased‐array antennas, digital beamforming (DBF) array antennas, parasitic array antennas, diversity antennas, and multiple input multiple output (MIMO), are discussed. The article concludes with a comparison of different adaptive array antenna architectures.
Corrugated Horn Antennas
Authors: Gentili Gian Guido , Nesti Renzo , Pelosi Giuseppe , Selleri Stefano 
Published: December 2024

AbstractIn this work, the basic theory of circular corrugated horn antennas is presented, using easy concepts with simple mathematics. The aim is to give the reader an understanding of the fundamental electromagnetic properties of these devices and to provide a set of quantitative design tools for the electromagnetic engineer.The wave propagation problem in corrugated waveguides is approached by approximating the field boundary conditions on the corrugation limit surface and by making further assumptions, suggested by practical considerations, with a consequent mathematical simplification of the theory. This approach has the major advantage of providing an analytical solution for the electromagnetic field, which is accurate as far as the approximate boundary conditions are valid, highlighting the most relevant features of corrugated waveguides.The problem of radiation from corrugated horns is addressed in a similar way by choosing an approximated model sufficiently accurate for almost all practical needs. This model, the “Gaussian beam model,” has a simple analytical formulation and is rigorously treated. The final result of this approach is a set of analytical formulas relating electromagnetic properties to geometric parameters that are very useful in the design.Then, further design aspects concerning the throat region, the phase center, and cross‐polarization are introduced and numerical methods for highly accurate analysis of corrugated horns are described, ending with some design examples.
Frequency Selective Surfaces
Authors: Wu Te‐Kao 
Published: December 2024

AbstractA summary description of frequency‐selective surface (FSS) is provided. Subjects covered include various kinds of FSS and characteristics, bandpass and bandstop FSS, aperture and patch element FSS, thin/thick‐screen FSS, FSS analysis techniques and design tools, dielectric loading effects, grating lobe and Wood's anomaly, as well as various FSS applications and developments. An FSS bibliography is also provided listing all the references necessary for further research on the subject of FSS.
Lens Antennas
Authors: Malherbe Johannes A. G. 
Published: December 2024

AbstractLenses can be employed to act as high‐gain scannable antennas. The optical principles that apply to lens antennas are discussed, as well as the materials used in the construction of lenses. The basic lens function is discussed, and examples given of simple planoconvex and planoconcave lenses, together with the equations that describe the lens surfaces. In order to reduce the lens size, lenses are zoned, and equations for lens zoning are given. Other lens parameters such as gain, sidelobe level, reflections, loss, and bandwidth are treated. Lens systems for scannable or multibeam antennas are described, and design and analysis procedures for Rotman lenses given. Other lenses discussed include Luneburg,R‐2R, integrated dielectric, and Fresnel zone lenses. Physical construction methods for Rotman, Luneburg, and Fresnel zone plate lenses are discussed. This includes three‐dimensional (3D) printing and use of metamaterials.
Orthomode Transducers
Authors: Gentili Gian Guido , Nesti Renzo , Pelosi Giuseppe , Selleri Stefano 
Published: December 2024

AbstractIn the present work, orthomode transducers (OMTs) and polarizers are presented. First, field configurations and propagation properties in common waveguides, which are extensively used in OMTs and polarizers, are analyzed to provide the reader with the necessary background to understand both devices.As a second step, some OMTs and polarizers are described in an attempt to highlight their electromagnetic features; this is not intended as a full review of all the known OMT and polarizer configurations, which is beyond the scope of this work, but to provide the reader with a basic knowledge of the principles of their operation. This is done by choosing a small, but representative, set of configurations largely used in practice that analyzed in depth, in the author's opinion, gives the reader a fundamental understanding and a broad knowledge of the argument.Finally, three example designs of two OMTs and one polarizer are presented.
Radar Antennas
Authors: Li Long , Xu Peng , Han Jiaqi , Feng Qiang , Cui Tie J. 
Published: December 2024

AbstractThe radar antenna plays an important role in the radar system, and the requirement of radar antenna performances and functions is varied with different radar types. The radar antenna forms a highly directive beam in both transmit and receive modes, which achieve accurate angular targets and resolve closely located targets, and this important feature of the radar antennas can be quantitatively expressed in terms of the beamwidth, gain, and sidelobes. Besides, the functions of radar antennas can be classified into beam scanning (search or surveillance target) and target tracking. In the increasingly complex electromagnetic (EM) world, digital coding and programmable metamaterials and metasurfaces have been enabling commercial opportunities with a broad impact on radars and wireless communications. Because the subject of radar antennas is very extensive, in this chapter, only selected types and performances of radar antennas are discussed and then four different antennas (reflector antennas, phased‐array antennas, space‐fed arrays, and metamaterial antennas) are summarized.
RADIO RECEPTION
Authors: Zvonar Zoran 
Published: December 2024

AbstractMultiple factors influence the radio system performance, including radio propagation, radio link design, radio receiver design, and radio network design. The focus of this section is on the key elements of the radio reception that are starting point for the radio system design.Radio propagation addresses fundamentals of path loss prediction models, outdoor and indoor prediction models, and effects of environment and small‐scale variations resulting in multipath fading. The emphasis is on channel characterization and statistical propagation models. Radio link design part covers link budget and frequency planning. Section on man‐made noise and interference completes the list of external factors that influence radio performance. The aspects of radio receiver design include introduction to radio front‐end parameters, diversity techniques, modulation and coding, and interference suppression techniques.
WIRELESS COMMUNICATION SYSTEMS
Authors: Armada Ana G. , Gil Jiménez Víctor P. , Morales Céspedes Máximo , Chen Hu Kun 
Published: December 2024

AbstractThis chapter introduces wireless communications systems and explains the different products and standards related to wireless communications. The chapter is divided into five main sections.A brief introduction offers a perspective on the evolution of wireless communications systems and introduces a useful classification. After this introduction, an explanation of basic concepts and fundamentals of the different wireless products, followed by a presentation of the related technology the related technology.The introduction and the basic concepts showed make it easy to understand the presentation of the most important wireless products and related standards are detailed: cellular, cordless, trunking, paging, wireless local‐area network (WLAN), wireless metropolitan‐area network (WMAN), and wireless personal‐area network (WPAN) systems.Finally, a brief vision of the future evolution of wireless is disclosed, introducing advanced technologies and applications such as massive multiple input–multiple output (MIMO), light‐fidelity (LiFi), drones, and Internet of Things (IoT), and of actual research toward the next generation of mobile communications.
GYROTRONS
Authors: Ives Robert L. 
Published: December 2024

AbstractThe gyrotron is a vacuum tube capable of delivering high levels of radio‐frequency (RF) power at frequencies from several gigahertz to more than 500 GHz, which covers the microwave and millimeter‐wave band. Because of the structure of the RF fields in the cavity, the magnitude of the electric fields and the RF losses in the cavity walls are much lower in gyrotrons than in most microwave and millimeter‐wave vacuum tubes. As the RF frequency increases, it is not necessary to reduce the size of the cavity and output waveguide. For these reasons, the gyrotron is the principal RF device for delivering high levels of RF power at frequencies between 30 and 500 GHz.
STABILITY OF NONLINEAR SYSTEMS
Authors: Chen Guanrong 
Published: December 2024

AbstractThis chapter briefly presents the notion of stability of nonlinear systems in both continuous‐time and discrete‐time settings. Basic concepts and fundamental theorems of various system stabilities are introduced. These mainly include the important Lyapunov stability theory, along with some others particularly the orbital stability and the structural stability. The bounded‐input bounded‐output stability of maps is also discussed.
MONOPULSE TRACKING SYSTEMS
Authors: Sierra‐Pérez Manuel 
Published: December 2024

AbstractSince its first conception at the end of World War II, the monopulse principle has become the most extended way to get accurate information about the target angular position in radar systems. Both tracking radars and scan radars use this principle in the accurate determination of the angular deviation with respect to the antenna axis (OBA, off‐boresight angle). Now, not only radar but any radio communication systems that need to orientate a narrow beam antenna to the transmitter use monopulse tracking systems. Satellite or deep space sound communications use this kind of system to secure links with very narrow beam antennas. Identification friend and foe (IFF) military systems use this principle to get narrow beam information links.In this paper, the main characteristics of a monopulse tracking system are presented. First, a comparison to other angular detection tracking system is done to give the advantages of the monopulse. A brief description of the monopulse principle is introduced and a more extended description of antennas to obtain the main diagrams and monopulse processors to get the error signals are presented in the third and fourth sections.
VARIABLE‐FREQUENCY OSCILLATORS
Authors: Gutierrez Germán 
Published: December 2024

Abstract
Oscillators are abundant around us. Most oscillators are of two basic kinds: sinusoidal and relaxation. This chapter covers the main topologies for all popular oscillators and the ways to make their frequency of oscillation variable. The description is independent of frequency and can be applied from very‐low‐frequency to microwave oscillators. Mechanical examples give a very simple explanation for the mechanism of oscillators and the concept of resonance.

An
oscillator
is defined as anything that swings back and forth like a pendulum (vibrates) or travels back and forth between two points. An
electronic oscillator
is a device used for producing alternating current (e.g., a radio frequency or audio frequency generator).
Frequency
is the number of times that a periodic function repeats the same sequence of values during a unit of time or the number of complete oscillations of a wave per second.

Oscillators are abundant all around us: light, sound, the rotation of the Earth, electric AC power, heartbeats, musical instruments, motors, microprocessor clocks, etc. Some of these oscillatory systems have variable frequencies, and some have fixed frequency. We will first describe all the different types of electronic oscillators to appreciate what determines their operating frequency and how it can be varied.
SILICON MILLIMETER‐WAVE PHASED ARRAYS
Authors: Lee Wooram , Sadhu Bodhisatwa 
Published: December 2024

AbstractMillimeter‐wave technology, with its large available bandwidth, promises many new wireless applications, from cellular communications to automotive radar for self‐driving vehicles. The silicon integration of mmWave and phased array technology has opened the door for large‐scale deployment of such systems. This chapter provides an overview tutorial of silicon‐based millimeter‐wave phased arrays and key building blocks.
Efficient and Stable Perovskite Solar Cells with a Multifunctional Spiro‐Based Hole Transport Material
Authors: Liu Xuepeng , Zhang Xianfu , Zhou Ying , Dai Weiqing , Chen Jianlin , Syzgantseva Olga A. , Syzgantseva Maria A. , Li Botong , Ghadari Rahim , Han Mingyuan , Du Weilun , Shao Zhipeng , Wang Qian , Dai Songyuan , Nazeeruddin Mohammad Khaja , Ding Yong 
Published: December 2024

AbstractThe widely used spiro‐OMeTAD exhibits moderate interaction with the perovskite layer, which does not decrease the defect on the perovskite surface, thus limiting the photoelectric performance of perovskite solar cells. In this work, the spiro‐OMeTAD structure is functionalized with chlorine (Cl), resulting in a new material labeled spiro‐mCl, which interacts more effectively with the perovskite and passivating interface defects. In addition, the strong electronegativity of Cl lowers the Highest Occupied Molecular Orbitals (HOMO) energy level of spiro‐mCl, resulting in a better match with the valence band of perovskite. Additionally, the asymmetry introduced by Cl enhances the hole mobility and increases the glass transition temperature of spiro‐mCl. As a result, the device incorporating spiro‐mCl achieved an open‐circuit voltage of 1.16 V and a remarkable power conversion efficiency of 25.26% (certified at 24.88%), marking it as one of the highest‐performing spirobifluorene‐based HTMs in PSCs. Importantly, this device also demonstrated significantly improved operational stability compared to the one utilizing spiro‐OMeTAD.
High‐Performance and Scalable Organosilicon Membranes for Energy‐Efficient Alcohol Purification
Authors: Zhu Tengyang , Shen Dongchen , Dong Jiayu , Liu Huan , Xia Qing , Li Song , Shao Lu , Wang Yan 
Published: December 2024

AbstractThe production of bio‐alcohol is increasingly gaining international attention due to its potential as a viable alternative to fossil fuels and its ability to mitigate carbon dioxide emissions. However, the cost of bio‐alcohol production is almost double that of fossil fuels, primarily because of the low yield of the purification process. Herein, a high‐performance and scalable organosilicon membrane with high chain flexibility and controllable crosslinking density is developed for energy‐efficient alcohol purification. The synthesized organosilicon membrane achieves an ultrahigh total flux (5.8 kg·m−2·h−1) with a comparable separation factor (8.7) for ethanol/water separation, outperforming most state‐of‐the‐art polymer‐based membranes. Integrated experiments and molecular dynamics simulations confirm that the ultrafast alcohol permeation of the membrane originates from its high chain flexibility, large fractional free volume, and weak interactions between feed molecules and membranes. The universal applicability of the low‐crosslinking mechanism for the formation of high‐performance organosilicon membranes is also validated. Moreover, its high efficiency and scalability in membrane production, along with the stability of the casting solution, offer promising prospects for industrial applications.
A Mechanoluminescence‐Based Stress Sensing Hydrogel for Intelligent Artificial Ligament
Authors: Yan Chunmei , He Xiao , Yu Bo , Zhou Bo , Fang Shaofan , Xu Jia , Liu Bin , Wang Zhaofeng 
Published: December 2024

AbstractRobust and biocompatible hydrogels are recognized as promising biomimetic soft materials to improve human life quality. To ensure their stable, reliable, and safe service, the hydrogels are further required to have non‐contact and wireless stress sensing ability. Herein, a mechanoluminescence (ML) based micellar hydrogel is developed, in which the surface‐modified BaSi2O2N2: Eu2+ (M‐BSON) particles are chemically incorporated into the cross‐linked polyacrylamide/polymethyl acrylate (PAM/PMA) network structure. Because of the interactions between the M‐BSON particles and the PMA micelles, the as‐fabricated composite hydrogel exhibits enhanced mechanical properties with a mechanical strength of 2.73 MPa and a toughness of 3.40 MJ m−3, respectively. The chemical wrapping of the M‐BSON particles by the hydrophobic PMA micelles further protects the ML properties from water quenching, leading to remarkable stress‐induced luminescence under the water environment of hydrogel. Because of its desirable mechanical performance, attractive stress‐light responsiveness, and good biocompatibility, the M‐BSON incorporated hydrogel has the potential to be applied as an intelligent artificial ligament for stress self‐monitoring and failure warning. This work addresses the inhomogeneous dispersion and water quenching issues of the ML particles in hydrogel structure, which significantly promote ML applications in bionic engineering.
3D Printing of Proteins Via Temperature‐Dependent Amyloid Aggregation
Authors: Fu Chengyu , Pang Yanyun , Zhang Jinrui , Zhou Xingyu , Liu Yongchun , Li Min , Song Jinhua , Gao Yingtao , Wang Zhengge , Hu Bowen , Ji Wenrui , Hui Ziling , Wang Jinglin , Ma Jianing , Huang Zhaofang , Zhang Xu , Zhao Jian , Yang Peng 
Published: December 2024

Abstract3D printing of protein materials for creating bioactive scaffolds has attracted significant interest. However, achieving controllable and stable printing while replicating the ordered structure found in natural protein materials remains a key challenge. Herein, a universally applicable temperature‐dependent protein aggregation (TPA) strategy is reported to manipulate the unfolding, relaxation, and reorganization of protein chains to enable the 3D printing of amyloid‐like proteins. The disruption of internal disulfide bonds induces the unfolding and relaxation of protein, leading to the formation of an amorphous protein sol through chain entanglement as primary cross‐linking points. These relaxed protein chains further aggregate through conformational transition to initiate amyloid‐like protein aggregation rich in β‐sheet structures at high temperature, resulting in a protein gel with β‐sheet nanocrystals serving as secondary cross‐linking points. This gel facilitates the stable and precise extrusion‐based 3D printing of proteinaceous scaffolds with a hierarchically ordered structure. The biomedical potential of this 3D‐printed protein scaffold is preliminarily validated through its biomineralization capability and following application in bone tissue regeneration using rat skull defect models. This strategy demonstrates a facile approach for the controllable structural aggregation of proteins in vitro and holds great potential in the field of protein‐based scaffolds.
Green Engineering of Silicon and Titanium Dioxide Architectures and Realizing Downstream Applications
Authors: Dirkzwager Adriaan , Mallee Lloyd , Groeneveld Tim , Quayson Essi B. , Qumber Mohammed Al , van Dongen Teresa , McMillan Duncan G. G. 
Published: December 2024

AbstractBiomineralization has long been a source of inspiration and frustration for researchers in a wide variety of disciplines from ecologists and dental practitioners to materials scientists. An amazing variety of organisms have the capacity to produce inorganic mineral complexes through biomineralization. In this context, different organisms use proteins, peptides, and polysaccharides as templates to control the nucleation, growth, and morphology of structures containing minerals and metals. Due to lack of clarity in the field, distinctions are provided between the various biomineralization processes as Type I, II, and III biomineralization. Synthetic biomineralization is an emerging field in which these processes are applied to unnatural substrates to create useful inorganic materials with applications in a variety of fields. A comprehensive overview of silica and titanium oxide biomineralization is given, covering the major achievements this sub‐field has attained since its emergence. The ground‐breaking discoveries are focused based on the templating agent used and the mechanisms that are proposed in the field are discussed. Synthetic biomineralization are led, which are more recently demonstrated to have feasible applications in energy, electronics, construction, and biotechnology. These possibilities are discussed alongside prospects based on the current trend of research in the field.