bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐Frequency Broadcasting
Authors: Elliot Kim Andrew
Published: November 2024

High‐frequency (HF) broadcasting, more commonly known as
shortwave broadcasting
, employs the long‐distance capabilities of skywave propagation for transmissions over long distances. HF is used for international broadcasting. Some international broadcasters additionally use the mediumwave broadcast band (standard AM) to reach audiences in nearer target countries. HF is also used for domestic broadcasting in countries with large remotely populated regions (e.g., Russia, China, Canada, Australia) and in tropical countries, where the effectiveness of mediumwave broadcasting is reduced by poor soil conductivity and static from lightning.
Gyrators
Authors: Frey Douglas R.
Published: November 2024

Agyratoris a nonreciprocal electrical network. It is capable of transforming signals or energy represented in terms of one electrical quantity, such as voltage or magnetic field, to another electrical quantity that may be of similar type or of a complementary type, such as current or electric field. Such networks are quite useful in electronic systems, since one often wishes to design systems with a limited set of component types or with restrictions regarding certain physical parameters.
Microwave Heating
Authors: Osepchuk John M.
Published: November 2024

Microwave heating is only part of the noncommunications applications of electromagnetic energy and only part of the range of electromagnetic heating. The
microwave
range of the spectrum is variously defined. One prefers to think it is characterized by the fact that the dimension of the object to be heated is of the order of the wavelength. In practical terms this means heating at either 915 or 2450 MHz, two of the industrial, scientific, and medical (ISM) frequency assignments (in the United States) power or noncommunication applications.

By far the most dominant heating application is the microwave oven, which today operates at only 2450 MHz.
Amplifiers in RF Transceiver for Wireless Communication
Authors: Heo Deukhyoun , Upadhyaya Parag , Rajashekharaiah Mallesh
Published: November 2024

Wireless communication entails transmission and reception of data with air and surrounding environment as a communication channel. The channel, in this case the surrounding environment, therefore, dictates the quality of wireless communication. Wireless communication uses radio frequency (RF) as carrier frequency for data transmission and reception. The channel for RF communication (surrounding environment) is lossy, and thus, it is necessary to boost or amplify the signal levels during both transmission and reception. In the transmitter, the power amplifier (PA) is used to boost the signal power levels, and at the receiver, the low noise amplifier (LNA) is used to amplify the weak RF signals. The power amplifier and the low noise amplifier, consequently, dictate the quality of wireless or RF communication and therefore are critical in RF transceiver design.
Attenuators
Authors: Sundararajn Raji , Peterson Edward , Nowlin Robert
Published: November 2024

Attenuators are linear, passive, or active networks or devices that attenuate electrical or microwave signals, such as voltages or currents, in a system by a predetermined ratio. They may be in the form of transmission‐line, stripline, or wave‐guide components. The most commonly used method in attenuators is to place resistors at the center of an electric field. Due to the electric field, there is current induced, resulting in ohmic loss.
Fabry–Perot Resonators
Authors: Sauleau Ronan
Published: November 2024

The characteristics and the main applications of Fabry–Perot (FP) resonators are described at microwave frequencies, referring to a well‐documented state of the art.

This article is organized in three sections. In the first, we present the basic properties of plane‐parallel FP interferometers using the traditional ray approach. Their performance is defined mainly in terms of power reflectivity of both partially transparent mirrors. Nevertheless many microwave and millimeter‐wave FP cavities employ metallic strip gratings or meshes as reflecting parts. The impact of the dispersive characteristics of these mirrors is investigated in details in Section 2. For that purpose, we first study the scattering parameters of inductive and capacitive meshes using transmission‐line models and compare them to rigorous numerical results. Then we analyze the influence of the grid geometries on the performance of plane‐parallel FP cavities (frequency responses, resonant frequencies, half‐power bandwidth, and insertion loss). Finally design rules and multilayer FP structures with metallic or dielectric mirrors are briefly considered. Various applications are discussed in Section 3: (1) frequency filters and diplexers, (2) directive antennas and multibeam and frequency beam scanning antennas, (3) open resonators with spherical mirrors for dielectric measurement, and (4) quasioptical power combiners and oscillators.
IMPATT Diodes and Circuits
Authors: Mc Clymonds James W.
Published: November 2024

This article will explain the basic principles for designing IMPATT diode circuits, beginning with the characteristics of the diodes. General circuit principles will be discussed, and calculations of amplifier circuit performance will be illustrated. The general principles then will be applied to several types of single‐diode circuits. Last, an approach for building very high‐power transmitters with hundreds of diodes will be shown.
Leaky Modes and High‐Frequency Effects in Microwave Integrated Circuits
Authors: Mesa Francisco , Jackson David R.
Published: November 2024

This article investigates the high‐frequency effects that occur when sources or discontinuities are present on printed‐circuit transmission lines. Although many of the conclusions are general, the analysis and the results will focus on microstrip and stripline types of transmission lines, where there is a single‐strip conductor that is within a layered structure that may contain either one or two ground planes.
Transmission Line Theory
Authors: Settaluri Raghu K.
Published: November 2024

This article presents an overview of one of the important topics in RF and microwave engineering, the transmission line theory. In several ways, transmission line theory bridges the gap between electromagnetic theory and basic circuit theory. At high frequencies, when the physical lengths of transmission lines are comparable with wavelength, time‐delay effects become predominant, leading to the distributed nature of the transmission line. This article focuses on studying the phenomenon of wave propagation on transmission lines by using the cascaded equivalent lumped‐element representation and application of basic circuit theory principles. First, a quick description of several commonly used transmission line structures and a brief description about the propagating modes are presented. Transmission line equations, relating the voltage and current on a general transmission line are derived in time‐ and frequency‐domains. Next, wave propagation on infinitely long and finite length transmission lines is described. Propagation parameters, such as characteristic impedance and propagation constant, are derived in terms of transmission line parameters. Special cases of lossless, and distortionless lines are cosidered and their propagation characteristics are studied. Terminations such as open‐circuit, short‐circuit, and matched‐load are described, and the variation of input impedance, voltage, and current on the line is discussed. Next, the concept of standing wave ratio and reflection coefficient and their relationship to the input impedance is presented. Smith chart, a graphical representation to solve transmission line problems, is described along with few numerical examples. The article finally presents various network parameters of a general transmission line for application to microwave network analysis.
Waveguide Discontinuities
Authors: Sorrentino R. , Alimenti F.
Published: November 2024

This article deals with waveguide discontinuities that are unavoidably present in any microwave circuit either unintentionally or to the purpose of performing a prescribed function. After a brief introduction, this contribution illustrates the basic theory behind the modal analysis of such structures and their general properties. Finally a categorization of waveguide discontinuity is proposed with reference to some geometric characteristics that are related to the corresponding electromagnetic problem.
Waveguide Oscillators
Authors: Holzman Eric L.
Published: November 2024

Waveguide oscillators are DC‐to‐RF converters most commonly used as millimeter‐wave sources. This article describes the fundamentals of solid‐state, two‐terminal device oscillators employing waveguide circuits as resonators. Single‐device oscillators, varactor‐controlled oscillators, and waveguide resonant cavity combiners are overviewed.
Retrodirective Systems
Authors: Shiroma Wayne A. , Miyamoto Ryan Y. , Shiroma Grant S. , Ohta Aaron T. , Tamamoto Michael A. , Murakami Blaine T.
Published: November 2024

A retrodirective system reacts to an incoming signal from an unspecified direction by transmitting a response to that same direction, regardless of what that direction is. This automatic beamsteering feature, performed without any prior knowledge of the location of the source, makes retrodirective systems attractive for automatic pointing and tracking systems, microwave‐tracking beacons, radiofrequency identification, solar power satellites, and small‐satellite crosslinks. This article focuses on retrodirective antenna arrays and their applications and characterization. After reviewing the two basic retrodirective array architectures (Van Atta and phase‐conjugating arrays), several two‐dimensional and millimeter‐wave arrays are then discussed, as well as several key applications in wireless communications.
Telemetry
Authors: Boyadzhyan Victor
Published: November 2024

The purpose of a telemetry system is to convey measurement information reliably and transparently from a remotely located data generating source to users located in space or on earth. Typically, data generators are scientific sensors, science housekeeping sensors, engineering sensors, and other subsystems on board a spacecraft. The telemetry link is the voice of the spacecraft, providing two basic types of information: performance and experimental information.
Diodes
Authors: Misiakos Konstantinos
Published: November 2024

In electronics terminology, diode refers to a two‐terminal device that allows current to flow in one direction while it blocks the flow of current in the opposite direction. Such devices usually employ semiconductor junctions or metalsemiconductor junctions. There are also diodes made of vacuum tubes or metalpurely ionic crystal contacts. This article deals with semiconductor p‐n‐junction diodes because they are the most widely used in practice because of their versatility, reproducibility, stability, and compatibility with integrated circuit technology.
History of Wireless Communication
Authors: Leggatt Patt
Published: November 2024

Beginning with the discoveries of Michael Faraday and then examining the work of the Maxwellians, Lodge, Fitzgerald, Heaviside, Hertz, Edison, Armstrong, and others, the history of wireless communications from 1831 to 1915 is presented. The article leaves off with Armstrong in 1915, whose triode oscillator paved the way for modern electronics and specifically wireless devices.
Data Analytics for Organizational Development Operations Analytics
Authors: Kaufmann Uwe H. , Tan Amy B.C.
Published: November 2024

For organizations to stay competitive, the need for emphasizing data‐driven analysis and decision‐making in operations rather than just customer‐focused processes is becoming a strategic priority. Operations analytics is important as all organizations consist of a multitude of processes with many steps and activities. Describing them with relevant data, building a data‐driven model, and establishing a relationship between process output and process parameters are key in operations analytics.

This has been done in manufacturing processes for decades and is also feasible in non‐manufacturing transactional processes.
MILITARY COMMUNICATIONS
Authors: Nguyen Tien M. , Wang Charles C. , Goo Gary W.
Published: December 2024

In general, military communication systems are different from ordinary systems in various specific security requirements, namely, robustness in hostile environments, shielding from adversaries, and immunity from unfriendly eavesdropping. Hostile environments to communications are radiofrequency interference (RFI), spoofing, jamming, and fading, either natural or human made. In recent years, synthetic aperture radar (SAR) has been extensively utilized for remote sensing.
HYBRID CAD TECHNIQUES
Authors: Arndt Fritz
Published: December 2024

Microwave components, antennas, and systems that meet the tight requirements of today's advanced wireless terrestrial and satellite‐based communication systems—in particular concerning increased specifications and performance—demandfastEM‐based computer‐aided design (CAD) tools yielding accurate, highly optimized components within adequately short design times. This goal makes flexible and efficient hybrid solutions desirable, which typically go beyond the design capabilities of the involved single methods. The chapter presents an overview of the state of the art of hybrid CAD mode‐matching (MM)/finite‐element (FE)/method‐of‐moments (MoM) techniques applied for the rigorous, fast CAD and optimization of waveguide components, antennas and arrays and describes recent advances. The hybrid techniques presented combine advantageously the efficiency of the MM method with the flexibility of the FE method and the efficiency and flexibility of MoM for radiating structures. Typical application examples illustrate the versatility and high efficiency of these hybrid techniques.
CONFORMAL MAPPING TECHNIQUES
Authors: Akan Volkan , Yazgan Erdem
Published: December 2024

Conformal mapping techniques (CMTs) can be applied in the analysis of many engineering applications such as boundary value problems and electromagnetic field problems. This article presents information about the formulation of the potential and flux functions and the most important properties and application procedures of some RF, microwave, and antenna engineering techniques.
MODE‐MATCHING METHODS
Authors: Arndt Fritz
Published: December 2024

The article presents an overview of the state of the art of mode‐matching (MM) methods applied for the rigorous, fast CAD and optimization of waveguide components and describes some recent advances. The great technical importance of the MM technique is its extremely high computational efficiency, achieving complete full‐wave analyses of typical waveguide components orders of magnitude faster than electromagnetics (EM)‐based methods applying space discretization techniques. Hence, the MM technique allows advantageously the direct EM‐based optimization of waveguides components toward given specifications within shortest response times. Hybrid combinations with other EM methods, such as the finite‐element (FE) method and method of moments (MoM), provide extended flexibility. Typical application examples will illustrate the versatility of the MM methods.
MONTE CARLO SIMULATION IN RELIABILITY
Authors: Leemis Lawrence M.
Published: December 2024

Simulation is a generic term used loosely in engineering, with application areas ranging from flight simulators used in cockpit design to simulated annealing used in optimization. Simulation is presented here as a mathematical and computational technique used to analyze probabilistic models. Simulation can be divided intoMonte Carlo simulation, in whichstaticmodels are analyzed, anddiscrete‐event simulation, in whichdynamicmodels involving the passage of time are analyzed. This chapter surveys algorithms for generating random variates for simulation in the setting of a reliability application.
SYNTHETIC APERTURE RADAR
Authors: Özdemir Caner
Published: December 2024

Since its invention in the early 1950s, synthetic aperture radar (SAR) has gathered increasing attention thanks to its attractive capabilities such as providing good resolutions both in range and in cross‐range dimensions. Although primary practices of airborne and spaceborne SAR systems were for surveillance purposes of geophysical remote sensing, other numerous applications of SAR have also been implemented in many areas from subsurface imaging to crop monitoring. This chapter begins with the history of SAR and presents the basic principles of SAR signal processing procedures such as range compression, range cell migration correction, and azimuth compression. Applications and some common problems in SAR imagery are covered as well. Principles of inverse synthetic aperture radar (ISAR) and its applications are demonstrated with examples. Advanced SAR concepts such as motion compensation, interferometric SAR, and polarimetric SAR imaging applications are also presented. The concluding remarks are devoted on some hot topics and emerging technologies in SAR imagery.
RADIO ASTRONOMY
Authors: Davidson David B.
Published: December 2024

This chapter addresses radio astronomy. Following a brief history by way of introduction, the historical impact of radio astronomy on astrophysics is discussed, as is its contemporary role in multi‐wavelength astronomy. Major contemporary science cases motivating the development of future radio telescopes are outlined. Sensitivity and resolution are introduced as two of the most fundamental metrics of a radio telescope, and the improvement over time of these metrics is documented. Thereafter, design considerations for radio telescopes are discussed. These include single‐dish systems and interferometric synthesis arrays. Design issues for both dish and aperture arrays are considered. The basic principles of interferometry and aperture synthesis are outlined, as well as very long baseline interferometry. New technologies impacting on current designs are highlighted, including phased array feeds, very low noise amplifiers, and electromagnetic simulation methods. Radio frequency interference is briefly considered. The chapter concludes with a look to the future of radio astronomy, in particular the Square Kilometer Array; construction of this international project was starting as this book was going to press.
THE USE OF PHOTONICS FOR ANALOG RF APPLICATIONS
Authors: Devgan Preetpaul S.
Published: December 2024

This chapter reviews the use of photonics for RF and microwave applications. As the need for more bandwidth increases, higher frequencies are being accessed. Photonics provides advantages over electronics at operating frequencies in the microwave and millimeter wave bands. This chapter provides examples of applications where photonics can be used. These applications include radio over fiber links, low phase noise clock signals, clock synchronization and simultaneous transmission and reception of RF signals. Photonics can address these applications and many more future use cases.
Evaluation and comparison of synthetic computed tomography algorithms with 3T MRI for prostate radiotherapy: AI‐based versus bulk density method
Authors: Karhula Sakari S. , Karppinen Piia , Hietala Henna , Nikkinen Juha
Published: November 2024

Purpose

Synthetic computed tomography (sCT)‐algorithms, which generate computed tomography images from magnetic resonance imaging data, are becoming part of the clinical radiotherapy workflow. The aim of this retrospective study was to evaluate and compare commercial bulk‐density‐method (BM)‐based and AI (artificial intelligence)‐based‐algorithms using 3T magnetic resonance imaging (MRI) with patient data as part of the local clinical commissioning process.

Methods

44 prostate radiotherapy patients were subjected to MRI and treatment planning CT (TPCT) scans. From the MRI images, sCT images with two different sCT algorithms were generated. The sCT images were evaluated by visual inspection of artifacts. Both sCT methods were compared to TPCT, with Dice similarity score(DSC) of bone and body contours, DVH parameters for CTV, bladder and rectum, and gamma‐analysis. Accuracy for treatment alignment using sCT images was also tested. Various limits were used to define whether the differences between sCT methods to TPCT were clinically relevant (DVH parameters <2%, gamma‐analysis passing rates 90%, 95%, and 98%, and the DSC 0.98 for body and 0.7 for bone).

Results

Our results show that, differences in CTV‐dose coverage values were <2% in most of the patients with both sCT algorithms when compared to reference dose coverage. While AI‐sCT had mean dose coverage difference <0,5% and BM‐sCT <1%. Gamma‐analysis showed that the AI‐sCT mean passing rates were 95.4%, 98.6%, and 99.4% with 1mm1%, 2mm2%, and 3mm3% criteria, respectively. Similarly for BM‐sCT the mean passing rates were 93.4%, 98.2%, and 99.2%. For the treatment alignment accuracy, the mean difference in magnitude of the translational shifts was 1.43 mm for BM‐sCT and 1.57 mm for AI‐sCT. Even though AI‐sCT showed statistically better correspondence to TPCT, the differences were not clinically relevant with any of the limits. Visual evaluation showed artifacts in the AI‐sCT especially in the bowel area and fiducial markers were not generated with either of the sCT algorithms.

Conclusions

In conclusion, sCT‐algorithms were clinically usable on prostate treatments using 3T MR‐only workflow. While AI‐sCT showed better correspondence to TPCT than BM‐sCT, it generated characteristic artifacts. As sCT algorithms perform well, we still recommend testing the sCT‐algorithms with retrospective analyses from patient data prior to implementing sCT into the routine workflow to better understand the specific limitations and capabilities of these algorithms.
pH‐Responsive and Therapeutic Liposomes for Enhanced High‐Intensity Focused Ultrasound Imaging and Therapy in Gynecologic Malignancies
Authors: Zhang Lin , Gao Xiaoyan , Yuan Jiangjing , Sheng Yaru , Chen Linfu , Shen Jingjing , Xu Chen , Wang Qi , Xiao Zhisheng , Wang Chunjie , Liu Nanhui , Liu Zhuang , Chen Qian , Wang Yudong
Published: December 2024

Clinical evidence suggests that high‐intensity focused ultrasound (HIFU) is emerging as an increasingly viable non‐invasive treatment for various gynecological diseases, demonstrating both high safety and effectiveness. Nevertheless, HIFU presents challenges in terms of energy dissipation and prolonged treatment time during the therapeutic process. In this study, liposomes containing ammonium bicarbonate (NH4HCO3) and paclitaxel (PTX), a first‐line chemotherapy drug, are utilized to enhance HIFU imaging and therapy. During HIFU treatment, the NH4HCO3 and PTX‐loaded liposomes (PTN@Lip) can release CO2 and NH3 in the tumor's acidic environment. These not only improve HIFU imaging but also regulate the tumor's acidic environment, thereby enhancing the uptake of PTX by tumor cells. Notably, the implementation of PTN@Lip and HIFU activates the immune system, leading to tumor inhibition or even elimination ultimately. This approach has the potential to address existing clinical treatment challenges and lay the groundwork for new directions in the treatment of gynecological tumors.
Reducing Surface Roughness to Achieve Li2CO3‐Existent Lithiophilic Interface in Garnet‐Type Solid‐State Batteries
Authors: Zhang Jiaxu , Wang Changhong , Fu Jiamin , Ye Minghao , Zhai Huiyu , Li Jun , Tan Gangjian , Tang Xinfeng , Sun Xueliang
Published: November 2024

The presence of Li2CO3 has been identified as the cause of poor lithophilicity in garnet‐type Li7La3Zr2O12 (LLZO) solid‐state batteries. A Li2CO3‐free garnet is expected to enhance the Li/LLZO interface contact. However, permanently eradicating regenerative Li2CO3 from the LLZO surface is extremely challenging and the influence of regenerated Li2CO3 is often ignored. Herein, it is found that glossy Li2CO3 pellets can also be perfectly wetted by molten Li, contradicting the common belief that Li2CO3 is lithiophobic. Therefore, reducing the surface roughness of LLZO allows it to be directly wetted by lithium metal, regardless of the presence of Li2CO3. Additionally, smooth LLZO exhibits better air stability due to its reduced active area. The symmetric cell with a smooth LLZO pellet shows a low interfacial impedance of 2 Ω cm2 and a high critical current density of 1.4 mA cm−2 at 25 °C. This work highlights the surface physics of garnet which significantly influences its interface properties, apart from surface chemistry.
Multifunctional Polymeric Nanoneedles with “Full‐Spectrum Intrinsic Internal Standard” for Precise SERS Biosensing
Authors: Wang Li , Li Chonghui , Cao Chongfeng , Lei Fengcai , Zhao Xiaofei , Li Zhen , Zhang Chao , Jiao Yang , Yu Jing
Published: November 2024

Polymeric micro and nanoneedles have an exceptionally flexible bio‐SERS structure. However, during detection, Raman signals from the polymer often overlap with those from the target molecules, which is unavoidable and severely compromises the accuracy of the results. To address this issue, this study designed and fabricated a silver (poly(vinyl pyrrolidone)‐coated, PVP)/poly(vinylidene fluoride) (PVDF)/gold nanoneedles structure (Ag/PVDF/Au NNs) and proposed a full‐spectrum intrinsic internal standard (FS‐IS) analytical method. In this method, the entire spectra of PVP and PVDF within the Raman fingerprint region are used as an internal standard, and machine learning algorithms are employed to quantitatively analyze the relevant SERS detection from a statistical perspective. Both the experimental and theoretical results demonstrate that this method is more accurate than traditional analysis methods based on embedded or intrinsic internal standards. Using the FS‐IS analysis method, the Ag/PVDF/Au NNs are successfully applied to various biosensing applications, including cancer cell imaging and in situ monitoring of antibiotics in the urine of surgical patients. This study effectively addresses the issue of low detection accuracy in flexible nanoneedle SERS structures and provides valuable insights for the development of other high‐precision detection technologies based on flexible substrates.
Anomalous Electrochemical Aging Strengthening Behavior of MXene Electrodes for Synergistic Anion‐Cation Storage in Dual‐Ion Batteries
Authors: Jia Rui , Yang Rui , Zheng Yongping , Pan Qingguang , Zhang Fan , Tang Yongbing
Published: November 2024

Electrochemical aging of electrode materials usually leads to capacity decay and voltage drop in conventional rocking‐chair batteries. Here we report an anomalous electrochemical aging strengthening behavior of Ti3C2Tx MXene electrode in a dual‐ion battery, whose capacity/power grows under cycling and eventually reaches an optimal state once the co‐storage of PF6− anion and Li+ cation is activated by a wide electrochemical aging window. Experimental and theoretical results reveal that there is anion‐cation synergy between PF6− and Li+ during co‐storage process in Ti3C2Tx electrodes, where small Li+ intercalation expands interlayer spacing of Ti3C2Tx at low discharge voltages, and the residual Li+ during charging can act as an anchor center to promote storage of large PF6− at high charging voltages; meanwhile, the residual PF6− during discharge in turn provides additional active sites to coordinate with Li+, raising Li+ intercalation voltage and capacity. Thereafter, Ti3C2Tx electrode offers a high capacity of 310 mAh/g, robust cycling stability over 800 cycles, and rate performance up to 1000 mA/g, which is among the best reported results of anion‐cation co‐storage. This counter‐intuitive discovery, resembling aging‐strengthening phenomenon in metallurgy, deepens our understanding of unconventional battery chemistry and provides a new avenue for design of high‐performance electrode materials.
Ubiquitous Liquid Metal 3D Printing: From Gas, Liquid to Rigid Media
Authors: Shan Xiaohui , Feng Weichen , Cui Ziliang , Guo Minghui , Huang Hongshi , Wang Jian , Zhu Xiyu , Yuan Ruizhi , Cao Yingjie , Wang Bo , Qiao Huiyu , Wang Xuelin , Liu Jing
Published: November 2024

Liquid metals (LMs) are opening large spaces for achieving functional 3D printing. However, previous fabrication strategies ever developed so far can only address a specific printing task that has yet to fulfill various needs. Conceiving that all fabrications and their output quality are dominated by the interactions between printing inks and their ambient environment, this review is dedicated to presenting a generalized framework toward the ubiquitous LM 3D printing and summarizing its fabrication category thus integrated. A panoramic view is provided that intentionally administrating the interfacial interactions among different media can guide ink modification and printing optimization. Further, the interactions between LM inks and various media are interpreted, ranging from gases, and liquids to soft matters, biological tissues, and even rigid materials, exploring key mechanisms such as oxidation facilitation, heat dissipation, structural support, modulus matching, strong wettability, and high reactivity. Following that, the LM inks, typical printing technologies, diverse working media, and enabled applications are reviewed. The elucidation of these interactions, particularly physical and chemical effects, can lead to the incubation of future LM 3D printing centers. It is expected that interactional LM 3D printing can mold additive manufacturing into ever‐powerful tools in the coming time.
Layered Double Hydroxides for Radium‐223 Targeted Alpha Therapy with Elicitation of the Immune Response
Authors: Yang Mengdie , Li Jianguo , Han Zongtai , Luan Xiaohui , Zhang Xiaoyi , Gao Jie , Qin Shanshan , Yu Fei
Published: December 2024

Targeted Alpha therapy (TAT) has promising application prospects in tumor therapy. It is very appealing to design alpha‐emitting radiopharmaceuticals that can modulate the immune microenvironment to overcome the limitations of immunotherapy. Herein, Mg/Al layered double hydroxide nanomaterials (LDH) are utilized to load the alpha‐emitting nuclide Radium‐223 (223Ra), achieving precise delivery of 223Ra to the tumor microenvironment. Dual‐modal imaging is employed to dynamically monitor the in vivo distribution of 223Ra‐LDH, ensuring its prolonged retention at the tumor site. In vitro experimentsshowed that ionizing radiation from alpha‐emitting nuclides effectively reduced glutathione (GSH) and produced large amounts of reactive oxygen species (ROS), which damaged mitochondria and released free calcium (Ca2+), thereby aggravating tumor cell death. Additionally,  DNA double‐strand breaks induced by alpha‐emitting radiation triggered the STING signaling pathway, which in turn effectively induced immunogenic cell death (ICD) and promoted immune cell maturation and activation. The synergistic effect with immunotherapy triggered a powerful systemic antitumor immune response. Overall, this study develops a novel TAT therapeutic strategy with sufficient antitumor immunity.
Localized Hydrogel Microspheres for Osteoarthritis Treatment: Recruitment and Differentiation of Stem Cells
Authors: Pang Qiming , Chen Zhuolin , Zhan Jingdi , Liu Jiacheng , Liu Junyan , Zhao Weikang , Huang Wei , Dong Lili
Published: November 2024

Osteoarthritis (OA) represents a common degenerative joint disorder marked by progressive cartilage degradation, necessitating innovative therapeutic approaches beyond symptom management. Here, this study introduces a novel strategy leveraging the regenerative capabilities of mesenchymal stem cells (MSCs) by utilizing a bioactive extracellular matrix (ECM) derived from IFN‐γ‐stimulated MSCs, encapsulated within aldehyde‐ and methacrylic anhydride‐modified hyaluronic acid hydrogel microspheres (AH). This engineered scaffold effectively mimics the native cartilage microenvironment, promoting targeted adhesion and retention at damaged sites via spontaneous Schiff base reactions. Notably, the IFN‐γ‐ECM@AH microspheres facilitate the localized release of key chemokines, such as CXCL12, enhancing endogenous stem cell recruitment, and bioactive factors (e.g., TGF‐βI and TGF‐β3) to drive chondrogenic differentiation. Additionally, the scaffold possesses binding sites for cellular integrins, further augmenting the regenerative potential of stem cells. Collectively, the approach presents a dual‐action mechanism that supports efficient cartilage repair and regeneration, positioning this engineered microenvironment as a promising therapeutic avenue for OA and potentially other degenerative conditions.
Surface‐Assisted Passivation Growth of 2D Ultrathin β‐Bi2O3 Crystals for High‐Performance Polarization‐Sensitive Photodetectors
Authors: Guo Yang , Zhang Qing , Ren Zebin , Li Lin , Ma Weijie , Shen Xianfeng , Dong Jichen , Li Rongjin , Geng Dechao , Hu Wenping
Published: December 2024

2D nonlayered materials (NLMs) have garnered considerable attention due to unique surface structure and bright application prospect. However, owing to the strong interatomic forces caused by intrinsic isotropic chemical bonds in all directions, the direct synthesis of ultrathin and large area 2D NLMs remains a tremendous challenge. Here, the surface‐assisted passivation growth strategy is designed to synthesize ultrathin and large size β‐Bi2O3 crystals with the thickness down to 0.77 nm and the lateral size up to 163 µm. These results are primarily ascribed to the bonding between Se atoms and the unsaturated Bi atoms on the surface of β‐Bi2O3, resulting in the surface passivation and promoting the obtaining of ultrathin β‐Bi2O3. Strikingly, the photodetectors based on β‐Bi2O3 flakes exhibit a high photoresponsivity of 71.91 A W−1, an excellent detectivity of 6.09 × 1013 Jones, a remarkable external quantum efficiency of 2.4 × 104%, an outstanding anisotropic photodetection and excellent UV imaging capability at 365 nm. This work sheds light on the synthesis of 2D ultrathin NLMs and promotes their applications in multifunctional optoelectronics.
Operando Studies Redirect Spatiotemporal Restructuration of Model Coordinated Oxides in Electrochemical Oxidation
Authors: Guan Daqin , Xu Hengyue , Huang Yu‐Cheng , Jing Chao , Tsujimoto Yoshihiro , Xu Xiaomin , Lin Zezhou , Tang Jiayi , Wang Zehua , Sun Xiao , Zhao Leqi , Liu Hanwen , Liu Shangheng , Chen Chien‐Te , Pao Chih‐Wen , Ni Meng , Hu Zhiwei , Shao Zongping
Published: December 2024

Tetrahedral, pyramidal, and octahedral metal‐oxygen coordinated ligands are fundamental components in all metal‐oxide structures. Understanding the impacts of their spatiotemporal behaviors during electrochemical oxidation is crucial for diverse applications, yet remains unsolved due to challenges in designing model oxides and conducting operando characterizations. Herein, combining a suite of advanced operando characterizations and systematic computations, a link between oxygen‐evolving performance and operational structural properties is established on model oxides. Compared with tetrahedral and octahedral structures, pyramidal structure is more susceptible to OH− attack due to its pristine unsaturated and asymmetric features and constant single‐electron occupancy on the active z2 orbital during reaction, leading to surface‐to‐bulk restructuration into active amorphous high‐valence CoOOHx with edge‐sharing configurations. This is accompanied by ion leaching to create nanoscale space, following a leaching tendency of Sr2+ > Ba2+ > La3+ > Y3+. Operando soft X‐ray absorption spectroscopy demonstrates a harder non‐uniform dehydrogenation process over time (Co3+OOH → Co3+/4+OOHx → Co4+OO) because of the enhanced CoO covalency with higher energy barriers. Lattice oxygen participates in active CoOOHx formation but sacrifices stability. To address this activity‐stability trade‐off, an ion‐tuning strategy is proposed to simultaneously enhance both activity and stability in electrode and device.
Crystallinity‐Controlled Hexagonal Boron Nitride‐Based Memristors for Fully Integrated Reservoir Computing Processors
Authors: Ahn Wonbae , Lee Sejin , Oh Jungyeop , Lee Hyeonji , Choi Sung‐Yool
Published: December 2024

Memristors based on 2D materials (2DMs) have attracted considerable research interest due to their excellent switching performance. Former synthesis methods for 2DMs aimed to synthesize 2DMs with a large grain size. However, these methods cause a stochastic distribution of defects in high‐density memristor arrays, resulting in device nonuniformity. Moreover, high synthesis temperatures and mechanical transfer make it difficult to implement large‐area memristor arrays and additional integration. Therefore, synthesis methods of nanocrystalline 2DMs for memristors are essential. In this study, crystallinity‐controlled hexagonal boron nitride is directly synthesized on metal electrodes, and a fully integrated memristor‐based reservoir computing processor is implemented. Memristors using nanocrystalline hexagonal boron nitride (NC h‐BN) exhibit volatile switching and reliable reservoir dynamics. Memristors using amorphous boron nitride (a‐BN) exhibit nonvolatile switching and linear potentiation/depression curves (αP = −0.475, αD = 0.656). By integrating NC h‐BN and a‐BN memristors in three dimensions, an efficient reservoir computing processor with integrated reservoir and readout layers is realized. Overall, the neural network of the integrated processor shows high accuracy for inferring temporal data. Hence, the crystallinity‐controlled hexagonal boron nitride synthesis method paves the way for the realization of fully integrated reservoir computing processors.
Highly‐Buckled Nanofibrous Ceramic Aerogels with Ultra‐Large Stretchability and Tensile‐Insensitive Thermal Insulation
Authors: Dang Shixuan , Guo Jingran , Deng Yuanpeng , Yu Hongxuan , Zhao Han , Wang Duola , Zhao Yingde , Song Chuanyun , Chen Jiali , Ma Minglei , Chen Wenshuai , Xu Xiang
Published: December 2024

Ceramic aerogels have exhibited many superior characteristics with promising applications. As an attractive material system for thermal insulation under extreme conditions, ceramic aerogels are required to withstand complex thermomechanical stress to retain their super‐insulating properties but, they often suffer from severe fracture damage that can lead to catastrophic failure. Herein, inspired by the tendrils of Parthenocissus, we report a design and synthesis of ultra‐stretchable ceramic aerogels constructed by highly buckled nanofibers. The buckling of nanofibers is formed by asymmetric deformation through two‐component off‐axial electrospinning method. The resulting aerogels feature an ultra‐large stretchability with a tensile strain of up to 150% and high restorability with a tensile strain of up to 80%. They also display a near‐zero Poisson's ratio (4.3 × 10−2) and a near‐zero thermal expansion coefficient (2.6 × 10−7 per °C), resulting in excellent thermomechanical stability. Benefiting from this ultra‐stretchability, the aerogels exhibit a unique tensile‐insensitive thermal insulation performance with thermal conductivities remaining only ≈106.7 mW m−1 K−1 at 1000 °C. This work promotes the development of ceramic aerogels for robust thermal insulation under extreme conditions and establishes a set of fundamental considerations in structural design of stretchable aerogels for a wide spectrum of applications.
Asbestos Burden in Lungs of Subjects Deceased From Mesothelioma Who Lived in Proximity to an Asbestos Factory: A Topographic Post‐Mortem SEM‐EDS Study
Authors: Visonà Silvia Damiana , Untalan Matthew , Bertoglio Barbara , Capella Silvana , Belluso Elena , Billò Marco , Ivic‐Pavlicic Tara , Taioli Emanuela
Published: November 2024

Background

Asbestos exposure and its pathological consequences, especially malignant mesothelioma (MM) still represent a major public health problem on a global scale. After the ban of asbestos in most western countries, nonoccupational exposure plays an essential role in MM pathogenesis. However, few studies have quantified asbestos lung burden after environmental exposure. The main objective of this work is to understand if asbestos lung content is different between occupationally and environmentally exposed individuals, and if the distance between the subjects' residences and the source of exposure is significantly associated with the asbestos lung burden.

Methods

In this retrospective, observational study we quantified, with analytical scanning electron microscopy, asbestos content in lungs of individuals deceased from MM between 2005 and 2019, who were exposed to asbestos (occupationally and/or environmentally) in Broni, a small town in northern Italy where an important asbestos‐cement plant operated until 1993.

Results

We analyzed asbestos lung content of 77 subjects. We found that the asbestos lung content in MM patients who lived around the asbestos factory was as high as that seen in occupationally exposed individuals; this holds true in residents up to 10 km radius from the factory. We found no significant associations between the residence duration/distance ratio and asbestos lung burden.

Conclusions

This study suggests that heavy asbestos pollution involves not only the area adjacent to the factory, but the entire town of Broni and the surroundings. This is alarming if we consider that most asbestos factories still active in some countries are located close to towns and dwellings.
Sex differences in the trajectories of plasma biomarkers, brain atrophy, and cognitive decline relative to amyloid onset
Authors: Joynes Cassandra M. , Bilgel Murat , An Yang , Moghekar Abhay R. , Ashton Nicholas J. , Kac Przemysław R. , Karikari Thomas K. , Blennow Kaj , Zetterberg Henrik , Thambisetty Madhav , Ferrucci Luigi , Resnick Susan M. , Walker Keenan A.
Published: November 2024

INTRODUCTION

The factors that influence the progression of Alzheimer's disease (AD) after individuals become amyloid‐positive are poorly understood. This study examines how sex influences the longitudinal trajectories of plasma AD and neurodegenerative biomarkers in the years following a person's estimated onset of amyloid‐β.

METHODS

Linear mixed‐effects modeling investigated overall and sex‐specific longitudinal trajectories of plasma biomarkers, brain volumes, and cognition relative to the estimated age of amyloid onset in a cohort of 78 amyloid‐positive Baltimore Longitudinal Study of Aging (BLSA) participants (n = 45 male; follow‐up time: 6.8 years [SD 3.31]). Amyloid status was ascertained with 11C‐Pittsburgh compound B (PiB) PET imaging.

RESULTS

After amyloid onset, men displayed steeper increases in pTau181, pTau231, and neurofilament light (NfL) compared to women. In this same period, men demonstrated steeper declines in brain volume and cognitive performance.

DISCUSSION

These findings suggest that sex influences the trajectory of AD pathology, neuronal injury, and symptom progression after individuals become amyloid‐positive.

Highlights

Steeper rates of increase in pTau and GFAP among amyloid‐positive individuals.

After amyloid onset, steeper increases in pTau and NfL concentrations in men than in women.

Steeper declines in brain volume and cognition in men corroborate biomarker results.
Engineered Reactive Oxygen Species (ROS)‐Responsive Artificial H+/Cl− Ion Channels for Targeted Cancer Treatment
Authors: Jia Chunyan , Luo Daoxin , Zhou Jin , Xie Xiaopan , Yuen In Lam Hilbert , Li Pengzhe , Mu Yuguang , Zeng Zhiping , Ren Changliang
Published: December 2024

Reactive oxygen species (ROS)‐responsive ion channels regulate the ion flow across the membranes in response to alterations in the cellular redox state, playing a crucial role in cellular adaptation to oxidative stress. Despite their significance, replicating ROS‐responsive functionality in artificial ion channels remains elusive. In this study, we introduce a novel class of artificial H+/Cl− ion channels activatable by elevated ROS levels in cancer cells. ROS‐induced decaging of the phenylboronate group triggers the rapid release of the channel‐forming units, leading to self‐assembly of the H‐bonded cascades facilitating the synergistic transport of H+ and Cl− ions, with H+/Cl− ion transport selectivity of 7.7. Upon activation, ROS‐C‐Cl exhibits significant apoptotic activity against human breast cancer cells, achieving an IC50 of 2.8 μM, comparable to that of paclitaxel. Exploiting the intrinsic oxidative microenvironment of cancer cells, along with the enhanced oxidative stress arising from H+/Cl− co‐transport, ROS‐C‐Cl demonstrates exceptional selectivity in targeting cancer cells with a selectivity index of 10.2 over normal breast cells, outperforming that of paclitaxel by 19.4 folds.
Electrochemical CO2 Fixation and Release Cycle Featuring a Trinuclear Zinc Complex for Direct Air Capture
Authors: Murase Masakazu , Sakamoto Naonari , Uyama Takeshi , Nonaka Takamasa , Ohashi Masataka , Sato Shunsuke , Arai Takeo , Itoh Toshiyuki
Published: November 2024

CO2 capture technology can mitigate greenhouse gas emissions and global warming. CO2 capture driven by electrochemical reactions is attractive because the operation is carried out at normal temperature and pressure and involves a simple input system using electrical energy. Although promising metal complexes with high CO2 fixation performance have been reported, there are few studies on systems that combine electrochemical reactions and metal complexes. Here, we demonstrated stable CO2 fixation‐release cycles using an electrochemical system with trinuclear Zn(II) complex (Zn3L) as the CO2 fixative and an ionic liquid as a supporting electrolyte for the stable operation. This system showed a faster CO2 fixation rate than that of an aqueous alkaline solution at the same concentration. Continuous release and refixation of CO2 were achieved by decomposition and reconstruction of the complex structure induced by H+ and OH− supplied from a bipolar membrane equipped in the electrolytic cell. The CO2 fixation‐release cycle was demonstrated even for dilute CO2 (450 ppm) in air, where the CO2 capture rate reached approximately 46 % of CO2 contained in the air under an air flow condition of 200 mL ⋅ min−1. This case, combining electrochemical drive and metal complexes, will provide a new option for CO2 capture technology.
Fighting Antimicrobial Resistance: Innovative Drugs in Antibacterial Research
Authors: Süssmuth Roderich D. , Kulike‐Koczula Marcel , Gao Peng , Kosol Simone
Published: November 2024

In the fight against bacterial infections, particularly those caused by multi‐resistant pathogens known as “superbugs”, the need for new antibacterials is undoubted in scientific communities and is by now also widely perceived by the general population. However, the antibacterial research landscape has changed considerably over the past years. With few exceptions, the majority of big pharma companies has left the field and thus, the decline in R&D on antibacterials severely impacts the drug pipeline. In recent years, antibacterial research has increasingly relied on smaller companies or academic research institutions, which mostly have only limited financial resources, to carry a drug discovery and development process from the beginning and through to the beginning of clinical phases. This review formulates the requirements for an antibacterial in regard of targeted pathogens, resistance mechanisms and drug discovery. Strategies are shown for the discovery of new antibacterial structures originating from natural sources, by chemical synthesis and more recently from artificial intelligence approaches. This is complemented by principles for the computer‐aided design of antibacterials and the refinement of a lead structure. The second part of the article comprises a compilation of antibacterial molecules classified according to bacterial target structures, e.g. cell wall synthesis, protein synthesis, as well as more recently emerging target classes, e.g. fatty acid synthesis, proteases and membrane proteins. Aspects of the origin, the antibacterial spectrum, resistance and the current development status of the presented drug molecules are highlighted.