bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiuser beamforming optimization for IRS‐aided systems with discrete phase shifts
Authors: Shi Mingli , Li Xiaohui , Fan Tao , Liu Jiawen , Lv Siting
Published: May 2022

Here, the beamforming design for multiuser multiple‐input and multiple‐output (MIMO) downlink transmission aided by an intelligent reflecting surface (IRS) with discrete phase shifts is studied. The authors deduce a minimum signal‐to‐interference‐plus‐noise‐ratio (SINR) maximization fairness problem with the transmit beamformer, the receive beamformer and IRS phase shifts as optimization variables, which is generally NP‐hard. Hence, an alternating optimization algorithm based on the gradient extrapolated majorization‐minimization (GEMM) approach is employed to solve the above problem. Specifically, when the transmit beamformer and reflective phase shift are fixed, the authors give an optimal closed expression for the receive beamformer. Then, the receive beamformer is fixed, and the minimum SINR maximization problem at the transmitter is transformed into a power minimization problem. Finally, under the zero‐forcing (ZF) transmitter beamformer, the GEMM algorithm is used to optimize the reflective phase shift. Simulation results show that by comparing to existing methods, the proposed GEMM algorithm can almost achieve the same performance with lower complexity.
Research on tracking method of moving object under the dynamic background
Authors: Wang Jie , He Xin , Yu Jiahui , Wang Jianyu
Published: May 2022

In order to solve the problem that the traditional moving target tracking algorithm is vulnerable to interference and difficult to accurately track the target for a long time, we first introduce the common target tracking algorithm under the dynamic background, and then we determine the KCF algorithm which has better tracking effect and real-time performance. Then, aiming at the problem of target box offset in the longtime tracking, a tracking algorithm combining Kalman filter algorithm and KCF algorithm is proposed. Finally, the actual effect proves to be effective.
Information fusion structure of VTS sensors for multi-target tracking of vessels
Authors: Chen Jingxue , Wang Jie , Lu Hua
Published: May 2022

Information fusion using VTS sensors of AIS, radar and camera are of great significance to the waterborne traffic supervision. Firstly, this paper invites shore-based CCTV cameras into detection and location of vessel targets combining with bounding boxes generated by deep-learning based detectors. Besides, this paper compares information fusion structure of central-level and track-level in simulated waterborne traffic scenario. Finally, this paper introduces a track selection method for sensors with large false alarm rate to obtain tracks with better performance on both fusion structure when fully considering strengths and weaknesses of all kinds of VTS sensors.
The research of emotion recognition based on multi-source physiological signals with data fusion
Authors: Han Yuanteng , Xu Yong
Published: May 2022

In the context of the increasing application value of emotion recognition and the continuous development of data fusion technology, it is of great significance to study the emotion recognition model based on multi-source physiological signals with data fusion. In this paper, the onedimensional-convolutional neural network-support vector machine (1D-CNN-SVM) emotion recognition model is constructed to extract the emotional features of multi-source physiological signal data, realize data fusion and complete emotion recognition. Firstly, based on the data level fusion method, dimension splicing for data of each channel is used to compare and analyze different data splicing combinations to explore the best one. Secondly, based on the feature level fusion method, the depth features of each part are fused and extracted by convolutional neural network models. Finally, feature stitching and support vector machine algorithm are used to classify and recognize emotion categories. The experimental results verify the effectiveness of the proposed model in the valence-arousal of the four-class task on DEAP dataset, and the recognition accuracy of the optimal combination can reach 93.10%.
Assessment method of depressive disorder level based on graph attention network
Authors: Lu Shengfu , Kang Jiaming , Zhang Jinyu , Li Mi
Published: May 2022

This paper presents an approach to predict the depression self-rating scale of Patient Health Questions-9 (PHQ-9) values from pupil-diameter data based on the graph attention network (GAT). The pupil diameter signal was derived from the eye information collected synchronously while the subjects were viewing the virtual reality emotional scene, and then the scores of PHQ-9 depression self-rating scale were collected for depression level. The chebyshev distance based GAT (Chebyshev-GAT) was constructed by extracting pupil-diameter change rate, emotional bandwidth, information entropy and energy, and their statistical distribution. The results show that, the error (MAE and SMRE)of the prediction results using Chebyshev-GAT is smaller then the traditional regression prediction model.
Experimental and simulation study on the influence of sand on heat dissipation performance of special vehicle radiator
Authors: Gui Yong , Zhou Liang , Zhang Qianqian , Liu Hongbin , Luo Qingguo
Published: May 2022

The radiator of special vehicle often exposed to sand condition, and the sand have great influence on the performance of radiator, in order to figure out the impact, the physical model of a radiator is built, the three-dimensional numerical simulation of the gas and water flow field of the radiator is carried out by adopting discrete phase model (DPM) as well as the SIMPLE scheme. Then, the relationship between different factors (such as air velocity, sand particle size, sand concentration) and heat transfer coefficient are obtained by means of simulation, which provides a basis for the optimization design of the special vehicle radiator. A test bench is built, and the simulation is verified to be correct by comparing the simulation result with the test result.
Analysis of equilibrium point based on nonlinear traffic flow model
Authors: Zhang Yifan , Ai Wenhuan , Liu Dawei
Published: May 2022

In this paper, the traveling wave solution of Kerner konhauser model is obtained by phase plane analysis method, and a new model suitable for stability analysis is obtained by variable transformation. The new model can describe and predict the nonlinear traffic phenomenon on Expressway from the perspective of system global stability. In this paper, the nonlinear system and linear system are obtained respectively by traveling wave substitution and Taylor expansion at the equilibrium point. According to the qualitative theory of differential equations, the equilibrium point type and stability of the linear system are determined. Finally, the simulation results show the consistency between the numerical results and the theoretical analysis.
Phase plane analysis of traffic flow based on driver’s expected response model
Authors: Xu Le , Ai Wenhuan , Liu Dawei
Published: May 2022

At present, researchers have proposed many traffic flow models and research methods of traffic phenomena, but few of them are analyzed from the perspective of system stability. Therefore, this paper proposes a phase plane analysis method from the perspective of traffic flow stability. This method can describe the nonlinear traffic flow phenomenon on the road from the perspective of system global stability. The nonlinear system of the model is obtained by traveling wave substitution and Taylor expansion, and the equilibrium point of the model is solved by specifying the model parameters. According to the qualitative theory of differential equation, the model is further analyzed to judge the type and stability of equilibrium point. Finally, the simulation diagram is used for numerical verification.
Enriched global horizontal irradiance prediction using novel ensemble improved backpropagation neural network
Authors: Madhiarasan M.
Published: May 2022

Penetration of solar energy into the power grid and smart grid is becoming an urge because of the continuous progress in industrialization and advancement. Requires a high accurate Global Horizontal Irradiance (GHI) prediction to achieve effective penetration of solar energy. This paper proposes a novel Ensemble Improved Backpropagation Neural Network (EIBPNN) with enhanced generalization ability because it is developed based on the various inputs’ individual improved backpropagation neural networks. Hence, the variance of individual IBPNN and input parameters based uncertainty are overcome and has the generic performance capability. The comparative analysis imparts the proposed prediction model results improved GHI prediction than the existing models. The proposed model has enriched GHI prediction with better generalization.
Super-metauniverse system engineering for ecosphere in internet of everything sky-earth computing (II) beyond cloud computing
Authors: Li Zongcheng
Published: May 2022

With the support of IT and network technology, we can develop and build a new system centered on cyber-tech users, integrating cyber-physical system (CPS-1) and its processes with cyber-physiological system (CPS-2) and its processes, cyber-psychological system (CPS-3) and its processes, as well as cyber-eventlogic system (CES) and its processes. It is proposed in this series of research to develop and produce a global service dispatcher (GSD) as the main component of a Sky-Earth computing console (SECC) for every user (individual, group, whole), and provide a customized world-wise brain. According to the analysis and design of this series of articles, through big data platform, Internet of things and artificial intelligence technology, we build intelligent integrated system, carry out data reconstruction system engineering, so as to establish the computer-like system (CLS) for big data processing, It combines all kinds of resource elements involved in computing in the information ecosphere with those involved in computing in the real ecosphere.
Research on space governance of scenic area village based on the concept of green sustainable development
Authors: Liu Weiyi , Yang Juan , Zhang Zhiqi
Published: May 2022

As a type of rural settlement left in the scenic area, scenic area village is faced with many practical problems, such as poor environmental quality, poor construction quality, lack of supporting service facilities, idle and wasteful houses of original residents, and the incompatibility between village appearance and scenic area. Therefore, it is urgent to strengthen space governance.Based on the new development concept and the framework of the linkage development of industry, village, landscape and people, taking Wuhan East Lake Scenic Spot as an example and combines the problem investigation, this article proposes a targeted approach through green construction, scenic area village style management and control, dynamic renewal and industrial upgrading to build a sustainable space governance framework of scenic area village that promotes production by landscape, optimizes village-industry cooperation, rejuvenates the village with production and strengthens integrated management of landscape and villages, and uses villages to rich landscapes and promotes the interaction of people and landscapes, with a view to provide technical reference for the construction of related “scenic area village” in China.
Research on the cooperation of industry-university-research in local universities based on game theory
Authors: Li Yang , Gao Rong
Published: May 2022

As the main part of China’s higher education system, local universities aim to serve regional economic and social development and focus on cultivating high-quality talents for the locality. However, compared with universities administrated by the ministry of education and other central agencies, local universities have certain disadvantages in the cooperation of Industry-University-Research. This research analyzes the difficulties and reasons of local universities in the cooperation of Industry-University-Research, and then puts forward corresponding suggestions for local governments and local universities from the perspective of game theory, including optimizing the promotion and regulation functions of the government, optimizing the mechanism of Industry-University-Research cooperation, and optimizing the school-running concept and evaluation system of local universities.
Multi-core fiber channel equalization algorithm based on K nearest neighbor method
Authors: Yu Yahui , Tian Feng
Published: May 2022

Aiming at the channel damage problems of multi-core fiber (Multi-core Fiber, MCF), the AKNN (Adapted K-Nearest Neighbor) algorithm is proposed. The MATLAB software was used to simulate the channel of the seven-core fiber, both the inter-core crosstalk (Crosstalk, XT) and nonlinear effects were considered. Then the KNN algorithm was adapted to equalize the damaged signal at the receiver. The simulation results show that the AKNN algorithm possesses better BER performance and lower OSNR requirements with the extension of transmission distance, compared to traditional KNN algorithm.
Two chaotic synchronizations in er-doped fiber lasers and their application in two-channel coding secure communications
Authors: Yan Senlin
Published: May 2022

A dual-ring erbium-doped fiber laser has nonlinear dynamic characteristics based on optical coupling interaction of lasing from the two laser rings and can send chaotic lasing to encode and mask an information to perform secure communication. Two independent groups of single-ring erbium-doped fiber lasers and a dual-ring erbium-doped fiber laser are used to construct two-channel chaos secure communication system while the synchronization’s physical mathematical model is presented by using the “active-passive” chaotic synchronization method, where a dual-ring erbium-doped fiber laser is used as a transmitter and two independent groups of single-ring erbium-doped fiber lasers are used as two receivers. Our numerical simulation shows that these two receivers can synchronize with the transmitter respectively. A two-channel chaotic hidden encoding secure communications with a modulation frequency of 10kHz analog signal and a rate of 20kbit/s digital signal are numerically simulated respectively, which shows to have good decoding quality and strong security. The obtained result shows that the chaotic coding system can be well applied in chaotic two channel secure communications. The research results have an important reference value for optical multi-channel secure communication and network security.
Preparation and Characterization of High Temperature Resistant Polyimide Films
Authors: Li Zhirui , Hou Yong , Ma Pengchang , Zhao Wenhua
Published: May 2022

To prepare high temperature resistant polyimide thin films, we have discussed the synthesis of high-purity diamine precursors in this study. We have prepared polyamide acid solutions first via two-step solution-based polymerization of heat-resisting diamine and dianhydride, and then obtain polyimides after dehydration during a high temperature curing process. The thermal, mechanical and hygroscopic properties of four polyimides thin films were tested and compared.
Immunologie Update für Dermatologen – woran wird geforscht?
Authors: Jahn Sigbert , Diamanti Evangelia , Herbst Matthias
Published: May 2022

Immuntherapien haben die Behandlung der chronischen Dermatosen enorm vorangebracht. Immunologische Diagnostik bestimmt den Alltag in der Praxis. Viele Dermatologen impfen. Nicht zuletzt die allgegenwärtige Corona-Pandemie und die Entwicklung entsprechender Impfstoffe verdeutlichen das große Forschungspotenzial in der Immunologie. Wir versuchen, einen Überblick zu geben, woran aktuell immunologisch geforscht wird und was wir in naher Zukunft zu erwarten haben.
Extraction algorithm for longitudinal and transverse mechanical information of AFM
Authors: Hao Chunxue , Wang Shoujin , Yuan Shuai , Wu Boyu , Yu Peng , Shi Jialin
Published: May 2022

The atomic force microscope (AFM) can measure nanoscale morphology and mechanical properties and has a wide range of applications. The traditional method for measuring the mechanical properties of a sample does so for the longitudinal and transverse properties separately, ignoring the coupling between them. In this paper, a data processing and multidimensional mechanical information extraction algorithm for the composite mode of peak force tapping and torsional resonance is proposed. On the basis of a tip–sample interaction model for the AFM, longitudinal peak force data are used to decouple amplitude and phase data of transverse torsional resonance, accurately identify the tip–sample longitudinal contact force in each peak force cycle, and synchronously obtain the corresponding characteristic images of the transverse amplitude and phase. Experimental results show that the measured longitudinal mechanical characteristics are consistent with the transverse amplitude and phase characteristics, which verifies the effectiveness of the method. Thus, a new method is provided for the measurement of multidimensional mechanical characteristics using the AFM.
Multi-field coupling mechanical failure of Pb(Zr0.95Ti0.05)O3 ferroelectric ceramics under shock compression
Authors: Zhang Fu-Ping , Du Jin-Mei , Liu Yu-Sheng , He Hong-Liang
Published: May 2022

PZT 95/5 ferroelectric ceramics have been used in shock-driven pulsed-power supplies for many years; their mechanical failure under shock compression plays an important role in their applications. Multi-field coupling shock experiments have been conducted to understand such failure by measuring the interface particle velocity of the quartz buffer/window interface, and the wave evolution was analyzed with or without the existence of failure zone inner PZT 95/5. Results confirm that the delay time of the failure wave decreased with increasing the electric field, and when the electric field reaches the dielectric strength, the electrical breakdown happens, which makes the threshold stress of mechanical failure shift to the low stress (2.0 GPa) and the delay time of the failure wave decreases dramatically at high stress. The phenomena that the delay time decreases with increasing shock stress are also observed. At the same time, ferroelectric → antiferroelectric phase transformation makes it so that the delay time of the poled state is longer than that of the unpoled state, so it has the effect of phase transformation toughening.
An angular-resolved scattered-light diagnostic for laser-plasma instability studies
Authors: Zhao X. , Yuan X. H. , Zheng J. , Dong Y. F. , Glize K. , Zhang Y. H. , Zhang Z. , Zhang J.
Published: May 2022

We developed an angular-resolved scattered-light diagnostic station (ARSDS) to extend the study of laser-plasma instabilities (LPIs) by simultaneously diagnosing their features at different angles in a single shot. The ARSDS angularly samples the scattered light using an array of fibers with flexible setups. The collected light is detected with an imaging spectrometer, a streaked spectrometer, or a fiber-optic spectrometer to provide time-integrated/time-resolved spectral information. The ARSDS was implemented at Shenguang-II Upgrade laser facility for the double-cone ignition campaigns. Preliminary results confirm the importance of an angular-resolved detection due to the angular dependence of LPI processes, such as stimulated Raman scattering.
When and how much a non-native tree species changes the temporal patterns and biomass of litterfall input in subtropical streams
Authors: Fontana Lucas Eugenio , Biasi Cristiane , Restello Rozane Maria , Hepp Luiz Ubiratan , Petrucio Mauricio Mello
Published: May 2022

Context In headwater streams, allochthonous litterfall input is an essential process to maintain the ecosystem functioning. The presence of non-native species in the riparian vegetation, with phenological characteristics distinct from those of most native tree species, can alter this process. Aims We evaluated the effect of the phenology of a non-native species (Hovenia dulcis) on the temporal patterns and biomass of litterfall input into streams by comparing one stream with (Hovenia stream) and another without (Native stream) H. dulcis in their riparian vegetation. Methods We quantified the litterfall input from native tree species and H. dulcis for 1 year by using buckets suspended above the streambeds. Key results The temporal pattern of litterfall input changed between streams, with quantitative differences between them during autumn and winter. In the Native stream, litterfall input was slightly higher in spring (∼79 g m−2 month−1), followed by winter (∼68 g m−2 month−1) and autumn (∼54 g m−2 month−1), whereas in the Hovenia stream, it was concentrated in autumn (∼126 g m−2 month−1). Conclusions and implications Our results indicated that the presence of H. dulcis in the riparian vegetation, when in high density, changes the temporal pattern and biomass of litterfall input into subtropical streams.
ENPP1’s regulation of extracellular cGAMP is a ubiquitous mechanism of attenuating STING signaling
Authors: Carozza Jacqueline A. , Cordova Anthony F. , Brown Jenifer A. , AlSaif Yasmeen , Böhnert Volker , Cao Xujun , Mardjuki Rachel E. , Skariah Gemini , Fernandez Daniel , Li Lingyin
Published: May 2022

Significance

The immune system strikes a careful balance between launching a robust response to threats and avoiding overactivation. The molecule cGAMP is an immunotransmitter that activates innate immunity and signals extracellularly, where it is subject to degradation by the enzyme ENPP1. Here, we engineer ENPP1 to lose activity toward cGAMP but not other substrates, thus creating a biochemically precise tool to understand how ENPP1 regulates extracellular cGAMP and thus innate immunity. We uncover that ENPP1's degradation of extracellular cGAMP has a long evolutionary history, and that this mechanism is critical for controlling diverse immune threats, including viral infection and inflammation.
Caspase-4/11 exacerbates disease severity in SARS–CoV-2 infection by promoting inflammation and immunothrombosis
Authors: Eltobgy Mostafa M. , Zani Ashley , Kenney Adam D. , Estfanous Shady , Kim Eunsoo , Badr Asmaa , Carafice Cierra , Daily Kylene , Whitham Owen , Pietrzak Maciej , Webb Amy , Kawahara Jeffrey , Eddy Adrian C. , Denz Parker , Lu Mijia , KC Mahesh , Peeples Mark E. , Li Jianrong , Zhu Jian , Que Jianwen , Robinson Richard , Rosas Mejia Oscar , Rayner Rachael E. , Hall-Stoodley Luanne , Seveau Stephanie , Gavrilin Mikhail A. , Zhang Xiaoli , Thomas Jeronay , Kohlmeier Jacob E. , Suthar Mehul S. , Oltz Eugene , Tedeschi Andrea , Robledo-Avila Frank H. , Partida-Sanchez Santiago , Hemann Emily A. , Abdelrazik Eman , Forero Adriana , Nimjee Shahid M. , Boyaka Prosper N. , Cormet-Boyaka Estelle , Yount Jacob S. , Amer Amal O.
Published: May 2022

Significance

We report the discovery of fundamental roles for the noncanonical inflammasome molecule Caspase-4/11 in promoting pathological inflammatory and prothrombotic pathways in severe acute respiratory syndrome coronavirus 2 (SARS–CoV-2) infections. Our work demonstrates that Caspase-11 has a broader role in immune responses beyond its previously appreciated effects in bacterial infections. Further, we show that Caspase-11–deficient mice infected with SARS–CoV-2 fare significantly better in terms of overall illness, lung inflammation, and thrombosis than wild-type (WT) mice, thus implicating Caspase-11 as a new therapeutic target for preventing or treating COVID-19.
Assessment of radiological health risk and radiogenic heat production changeability of different sedimentary rocks at Gabal Um Hamd, Southwestern Sinai, Egypt
Authors: Zaghloul Aya M , Abu-Zeid Hosnia M , El Aassy Ibrahim E , Talaat Shadia M , Abd El Maksoud Thanaa M
Published: May 2022

Soil is a source of natural radionuclides and a source of natural radiation risk to humans. This study aims to measure the radioactivity concentrations, contributions, radiological hazards and to quantify the radiogenic heat productions in thirty two rock samples having different lithology from the middle member of Um Bogma Formation in Gabal Um Hamd, southwestern Sinai, Egypt. The concentration of natural radionuclides was determined using a p-type Hyper Pure Germanium (HPGe) detector. The average activity concentrations of uranium

U

238

,
radium

R

226

a

,

thorium

T

232

h

,

and potassium

K

40

in the interested area were found to be 4909.58 ± 54.34

B
q
k

g

−
1

,

5003.12 ± 17.56

B
q
k

g

−
1

,

79.04 ± 8.82

B
q

kg

−
1

and 137.35 ± 8.64

B
q

kg

−
1

respectively. Other hazard indices average values were measured, such as: annual effective dose equivalent, radium equivalent activity, external and internal indices, annual gonad equivalent dose, and excess lifetime cancer risk. The radiologic hazards results, obtained in this study shows that the radiation levels are higher than the internationally approved values and the recommended safety limits. Furthermore, the results show that the radiogenic heat value ranged from 3.58 to 402.45 μW m

−3 with an average value of 60.11 ± 0.79μW m

−3 in the studied area which is higher than previously reported averages.
Quantum coherence protection by noise
Authors: Yang Xiuyi , Yin Hongjie , Zhang Feng , Nie Jing
Published: May 2022

In this paper, we propose a scheme to protect quantum coherence by adding another noise. We consider an example of a Jaynes–Cummings model coupled to an external non-Markovian bosonic bath. We solve this model by using the dressed state method in the presence of a stochastic coupling and obtain the density matrix by numerically averaging many stochastic trajectories. We show that the noisy atom-cavity coupling can effectively suppress both the relaxation and dephasing effects caused by the leakage of the cavity. Besides, we further illustrate the impacts of the standard deviation of the noisy coupling and the non-Markovian memory effect on the coherence protection. Then, the mechanism of the protection is analyzed. It is our hope that our research may open a new path to consider the role of noise in quantum coherence preservation.
Two near-infrared fluorescent probes based on dicyanoisfluorone for rapid monitoring of Zn2+ and Pb2+
Authors: Li Jia , Zhou Cuiping , Yang Hong , Wu Xiongzhi , Yan Liqiang
Published: May 2022

Zinc (Zn2+) and lead (Pb2+) ions in the environment have important effects on human health and environmental safety. Therefore, it is necessary to effectively detect them by a convenient and reliable analysis method. In this study, two near-infrared fluorescent probes for the fast determination of Zn2+ and Pb2+ were synthesized by a simple Schiff base reaction between the dicyanoisophorone skeleton and carbohydrazide derivatives. Among them, the probe with the thiophene-2-carbohydrazide group showed a selective fluorescence response to Zn2+ and Pb2+ with a maximum emission wavelength of 670 nm. And the detection limits of the probe for Zn2+ and Pb2+ were 1.59 nM and 1.65 nM, respectively. In contrast the probe modified by the furan-2-carbohydrazide group achieved quantitative detection of Zn2+, with a detection limit of 2.7 nM. These results were attributed to the fact that the probes bind to Zn2+ and Pb2+ in stoichiometric ratios of 1:1, blocking the intramolecular PET effect. Furthermore, these two probes can be recycled through the action of EDTA and have been successfully used to detect Zn2+ and Pb2+ in real water samples.
Fabrication of Cu-adhered silicon carbide particles and its effect on properties of Fe-based matrix composites
Authors: Jin Wubin , Zhou Yongmin
Published: May 2022

In present study, copper powders (Cu) and silicon carbide (SiC) particles were used to produce Cu-adhered SiC particles (Cu/SiC), which were used to reinforce Fe-based matrix materials to modify properties. The orthogonal experimental design was used to investigate the relationship between ball mill parameters and particle size. Next, the mixed powders were pressed at 500 MPa using a hydraulic press. Then, the green compacts were wrapped in graphite powders, and sintered using a resistance furnace. Metallurgical microscopy, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS) and x-ray diffraction were employed to investigate the microstructures, element distribution, and phase of SiC-reinforced Fe-based matrix composites. The properties of the SiC-reinforced metal matrix composites were determined using the Microhardness test and Charpy pendulum impact test. The orthogonal experimental results indicated that the influence degree of milling parameters on particle size was the powder to ball ratio>milling time>milling speed. The milling parameters to obtain the smallest Cu/SiC particle were powder to ball ratio of 20:1, milling time of 15 h, and milling speed of 300 r min−1. However, the adhesive effect was bad. The properties test results indicated that Cu/SiC particles reinforced with Fe matrix composites had better properties. Furthermore, the hardness and impact toughness improved up to 239.97 HV0.5 and 12.1 KJ·m−2, respectively. Moreover, compared to raw SiC particles, the hardness and impact toughness increased by 12% and 15%, respectively. The improvement in properties was attributed to the Cu adhesion to the SiC surface, which effectively alleviated the difference in thermal expansion coefficient between SiC and Fe, and formed a chemical bond at the interface to improve the interfacial binding
Single-Molecule Sequencing Enables Long Cell-Free DNA Detection and Direct Methylation Analysis for Cancer Patients
Authors: Choy L Y Lois , Peng Wenlei , Jiang Peiyong , Cheng Suk Hang , Yu Stephanie C Y , Shang Huimin , Olivia Tse O Y , Wong John , Wong Vincent Wai Sun , Wong Grace L H , Lam W K Jacky , Chan Stephen L , Chiu Rossa W K , Chan K C Allen , Lo Y M Dennis
Published: May 2022

Background

Analysis of circulating tumor DNA has become increasingly important as a tool for cancer care. However, the focus of previous studies has been on short fragments of DNA. Also, bisulfite sequencing, a conventional approach for methylation analysis, causes DNA degradation, which is not ideal for the assessment of long DNA properties and methylation patterns. This study attempted to overcome such obstacles by single-molecule sequencing.

Methods

Single-molecule real-time (SMRT) sequencing was used to sequence plasma DNA. We performed fragment size and direct methylation analysis for each molecule. A methylation score concerning single-molecule methylation patterns was used for cancer detection.

Results

A substantial proportion of plasma DNA was longer than 1 kb with a median of 16% in hepatocellular carcinoma (HCC) patients, hepatitis B virus carriers, and healthy individuals. The longest plasma DNA molecule in the HCC patients was 39.8 kb. Tumoral cell-free DNA (cfDNA) was generally shorter than nontumoral cfDNA. The longest tumoral cfDNA was 13.6 kb. Tumoral cfDNA had lower methylation levels compared with nontumoral cfDNA (median: 59.3% vs 76.9%). We developed and analyzed a metric reflecting single-molecule methylation patterns associated with cancer, named the HCC methylation score. HCC patients displayed significantly higher HCC methylation scores than those without HCC. Interestingly, compared to using short cfDNA (area under the receiver operating characteristic [ROC] curve, AUC: 0.75), the use of long cfDNA molecules greatly enhanced the discriminatory power (AUC: 0.91).

Conclusions

A previously unidentified long cfDNA population was revealed in cancer patients. The presence and direct methylation analysis of these molecules open new possibilities for cancer liquid biopsy.
Modification of reconstruction of left ventricular outflow tract, aortic root and the intervalvular fibrous body for extensive infective endocarditis: a single-centre experience
Authors: El-Sayed Ahmad Ali , Salamate Saad , Amer Mohamed , Abdullaahi Abdisalan , Bayram Ali , Sirat Sami , Bakhtiary Farhad
Published: May 2022

OBJECTIVES

Extensive infective endocarditis (IE) stays a serious life-threatening disease with high mortality and morbidity. The aim of this study is to analyse our experience with our modified surgical technique for extensive IE during the last 4 years.

METHODS

Between March 2017 and February 2021, all patients with extensive IE required our modified technique consisting of a radical surgical resection of all infected cardiac tissues, the replacement of infected valves and a reconstruction of the intervalvular fibrous body, the aortic root and the left ventricular outflow tract with modified elephant trunk were included in this study.

RESULTS

Our modified technique was performed on 41 patients during the study period. The age median was 74 [interquartile range (IQR): 66.5–76.5] and 61.0% (n = 25) were female. Thirty-three patients (80.5%) were in New York Heart Association Class III–IV and 7 patients (17.1%) in cardiogenic shock. The median logistic European system for cardiac operative risk evaluation II as predicted risk of mortality was 35% (IQR: 28–78%). The median cardiopulmonary bypass time and cross-clamping time were 126 (IQR: 86.5–191) and 78 (IQR: 55.5–108) min, respectively. Intraoperative mortality and 30-day mortality were 4.8% (2 patients) and 19.5% (8 patients), respectively. Low cardiac output with necessity for mechanical support, stroke and new renal dialysis developed in 9.8% (4 patients), 17.1% (7 patients) and 22.0% (9 patients), respectively. New pacemaker implantation was noted in 39.0% (16 patients). Intensive care stay and hospital stay had medians of 6 (IQR: 5–12) and 14 (IQR: 12.5–20.5) days, respectively. One-year mortality and 4-year mortality were 34.1% (14 patients) and 39.0% (16 patients), respectively. Kaplan–Meier survival estimates were 60.3% (95% confidence interval: 46.2–78.6%) at 3 years.

CONCLUSIONS

Our modified technique can be performed in patients with extensive IE with acceptable early and mid-term morbidity and mortality. We believe that this technique is an available option for this ill-fated group of patients.
C2 STEREOTACTIC ABLATIVE RADIOTHERAPY (STAR) IN PATIENTS WITH ICD AND ARRHYTHMIC STORMS
Authors: Molon G , Costa A , Bonapace S , Marinelli A , Alongi F , Giaj Levra N , Sicignano G , Cuccia F
Published: May 2022

Background

The current therapy of recurrent ventricular tachycardia (VT) and arrhythmic storms is the radiofrequency catheter ablation (RFCA). The first experiences of stereotaxic radioablation of arrhythmia (STAR) as an alternative in patients (pts) with defibrillator (ICD) and Arrhythmic Storms are emerging. However, a standardized method for STAR is not yet available and many issues are still under discussion. We present the preliminary results of STAR in the pts of our Center.

Material and method

Pts with ICDs and Arrhythmic Storms, excluded from RFCA, were referred to STAR. Diagnostics performed were Electrophysiological study (EPS) using 3D electroanatomical mapping (3DEAM) using CardioInsightTM vest (Medtronic, Minneapolis, MN), cardio–CT scan and 18F–fluorine–2–deoxy–D–glucose positron emission tomography (18FDG – PET scan) in order to identify the target area of the ventricle. In all pts a sustained monomorphic VT was induced during EPS, and 3DEAM was used to identify the exit point of the VT (Fig. 1). In all cases, a 3 mm thick 4D CT scan was used (Fig. 2) with the aid of an abdominal thermoplastic mask. Each patient was treated with a TrueBeam Linac (Varian Medical Systems, Palo Alto, CA). The prescription of the dose from 21 to 25 Gy in a single delivery. Ethics committee approval was obtained prior to each treatment.

Results

From January 2020 to March 2021, 6 patients (5 M, 1 F), mean age 78 years (58–80) were treated with STAR. The median delivered dose was 25 Gy (range 21–25 Gy). In follow–up (FU) one patient died from end–stage heart failure after 30 days. At a median FU of 13 months, STAR treatment efficacy was observed in 3/5 patients, in whom no defibrillator activation was recorded. 2/5 patients had recurrence of TV, 2 and 6 months after STAR. No severe acute toxicity was recorded after radiotherapy.

Conclusions

Arrhythmic stereotaxic radioablation appears to be a safe and effective therapy in PTS with ICDs and arrhythmic storms. Completely non–invasive diagnostics and therapy make it very interesting and ambitious. Additional data is needed to improve the definition of the target zone and to standardize it in patients not eligible for RFCA.
C3 A RARE AND ATYPICAL CASE OF ICD POCKET HEMATOMA CONTAINING PSEUDOCHYLOUS
Authors: Maffè S , Paffoni P , Bergamasco L , Facchini E , Prenna E , Careri G , Franchetti Pardo N , Paino A , Dellavesa P
Published: May 2022

Subcutaneous hematoma is a complication in 2–9% of cardiac device implants.In most cases, it is drained or spontaneously reabsorbed; if untreated, there is a risk of infection.While cases of chylothorax and pseudochylothorax are rare, no previous cases of accumulation of chyliform material in the subcutaneous pockets of cardiac devices have ever been documented.We present the case of a 60–year–old man with antibody syndrome antiphospholipids, rheumatoid arthritis, previous acute anterior myocardial infarction and aorto–coronary by–pass surgery, paroxysmal atrial fibrillation, in oral anticoagulant therapy. In 2020, the patient underwent primary prophylactic dual–chamber ICD implantation (EF 33%) at another center, complicated by the formation of a large pocket hematoma, which required drainage and evacuation. In the following weeks, the patient noticed the reappearance of a large swelling in the ICD pocket; however, as it was painless and not troublesome, he did not seek medical attention. After 7 months he came to our observation with signs of heart failure. Clinical examination revealed a large swelling in the left pectoral area (Fig. 1), extending to the nipple, soft, not painful, not hot or red.The patient had no signs of infection (normal ESR, CRP, procalcitonin and WBC). We decided to drain the hematoma, given the size. At the level of the defibrillator pocket, we made a small incision, from wich 100ml of gold–colored, odorless liquid leaked out (Fig. 2), with no evidence of blood material in the pocket. The ICD–case was then wrapped in a rifampicin–releasing antibacterial bag and reinserted into the subcutaneous pocket, without further complications. The chemical–physical examination revealed a cloudy, gold–colored liquid, density of 1020, pH 8.5, high protein content (>400g/l), absence of glucose.Microscopic examination shows isolated leukocytes, rare erythrocytes immersed in mucoid material; this was not pus, as culture testing was negative for bacterial growth. The cholesterol concentration was 704mg/dl, triglycerides 80mg/dl (plasma cholesterol values were 91mg/dl, triglycerides 48mg/dl). The cytological analysis showed a carpet of foamy macrophages filled with cholesterol crystals (Fig. 3). Such evidence supports the diagnosis of pseudochilous, formed from the evolution of an untouched hematoma in a fibrous subcutaneous pocket for more than 6 months.This is the first case in which the presence of chyliform material is documented in an ICD pocket.
C4 PERMANENT HIS BUNDLE PACING USING STYLET–DRIVEN LEAD IN PATIENTS WITH RIGHT ATRIOMEGALY: A SINGLE–CENTER EXPERIENCE
Authors: Marinaccio L , Giacopelli D , Rocchetto E , Vetta F , Marchese D
Published: May 2022

Background

His bundle pacing (HBP) is becoming an increasing widespread approach for physiological pacing. However, successful HBP procedure could be hampered by limited implantation tools especially in challenging anatomies. We aimed to report our experience with HBP technique using a novel stylet–driven lead system in patients with right atriomegaly.

Methods

Consecutive patients with right atrium (RA) volume >25 mL/m2 in men and >21 mL/m2 in women who underwent permanent HBP for standard indications were enrolled from March 2020 to March 2021. The tool of first choice for HBP attempt was a stylet–driven lead (Solia S 60, Biotronik) delivered via a dedicated introducer sheath (Selectra 3D, Biotronik). The acute, 1–month and 6–month procedural success rate was assessed.

Results

We enrolled 24 patients (median age 75 [70–79] years, 85% men) with an average RA volume of 50.7±7.8 mL/m2. At implant, conduction system pacing using stylet–driven lead was achieved in 21 patients (87%): 12 (50%) selective HBP, 6 non–selective HBP (25%) and 3 left bundle branch area pacing (12.5%). In the 3 failures, HBP was further attempted with a different system with final procedural success in 2 cases. In the successful cases, there was a significant reduction of QRS duration between paced and spontaneous beats (152.5 (130–167.5) ms vs 130 (122.5– 137.5) ms, p = 0.003). No lead dislodgment nor significant pacing threshold increase was observed at 1–month (1.30±0.76 V@0.4 vs. 1.32±0.80 V@0.4ms, p > 0.9) and 6–month follow–up (1.30±0.76 V@0.4 vs. 1.38±0.97 V@0.4ms, p = 0.66).

Conclusions

In our experience, the novel stylet–driven lead system showed high implant success rates and capture threshold stability also in patients with right atriomegaly.
C10 IN–HOSPITAL MANAGEMENT AND OUTCOMES OF ELECTRICAL STORM: SINGLE CENTER RETROSPECTIVE STUDY
Authors: Di Fusco S , Pignalberi C , Spinelli A , Matteucci A , Aquilani S , Pandozi C , Imperoli G , Colivicchi F
Published: May 2022

Background

Electrical storm (ES) is a condition characterized by the recurrence of malignant ventricular arrhythmia and is associated with significant morbidity and mortality. The aim of this study was to report the pharmacological and non–pharmacological interventions used to treat ES during hospitalization in an arrhythmia reference center.

Methods

We reviewed the medical record of patients consecutively admitted for ES in the intensive care unit of our center over a period of 6 years. Data on diagnostic tests and therapies used during hospitalization to manage these patients were retrospectively collected.

Results

Over the study period, 85 patients ((86% male, mean age 74±10 years) were admitted to the intensive care unit of our center for ES. Patient clinical, electrocardiographic, echocardiographic, and laboratory characteristics at hospitalization are reported in Table 1. Twenty–five patients had electrolytic disorders that required intravenous infusion of potassium and/or magnesium. Most patients (53%) were treated with at least one antiarrhythmic drug administered intravenously (Table 2). The most commonly used antiarrhythmic drug was amiodarone (38%). Twenty patients (24%) required more than one antiarrhythmic drug administered intravenously. Twenty–four patients (28%) underwent coronary angiography and seven patients (8%) required percutaneous coronary intervention (PCI). Twenty patients (24%) were treated with catheter ablation of the ventricular tachycardia during the index hospitalization, none of these also required PCI during the hospitalization. Six patients (7%) died during hospitalization after 9±10 days from ES onset, their mean left ventricle ejection fraction was 28% and none of them underwent ablation or PCI during the index hospitalization.

Conclusion

ES management in a reference center involves a comprehensive approach that includes multiple pharmacological and non–pharmacological interventions. Furthermore, our study confirms the severe prognosis associated with hospitalization due to ES.
C19 REMOTE MONITORING OF IMPLANTABLE CARDIAC DEVICES: ANALYSIS AND CHARACTERISATION OF ONE CENTRE‘S ACTIVITY SINCE THE START OF THE COVID–19 PANDEMIC
Authors: Campacci F , Biancoli S , Mazzotti A , Mattarocchia B , Cavezzi P , Orlati C , Biserni R , Galvani M , Bandini A
Published: May 2022

Introduction

The COVID–19 outbreak has accelerated the diffusion of remote monitoring (RM) in patients with Cardiac Implantable Electronic Devices (CIEDs). The primary objective of this analysis was to characterize the number of remotely monitored CIEDs in our centre since the start of the programme (November 2017) by comparing the number of patients monitored before and after the beginning of the pandemic (1 March 2020). The secondary objective was to quantify the number of scheduled hospital visits following the introduction of RM as an alternative to traditional outpatient monitoring from the first scheduled remote follow–up (1 November 2020) to the end the observation period (30 November 2021).

Materials and Methods

All patients with CIED compatible with RM technology (860 patients) were included. Information regarding CIED was obtained from CardioRef software (3A Sistemi, Castel San Pietro Terme, BO) and from the informative system in use in our Cardiology Department Log80 (Log80, Forlì, FC). All data were collected and analysed using Microsoft Excel software (Office 365 version).

Results

Seven hundred sixty–eight patients were provided with RM devices, which represent the 89.3% of monitorable CIEDs. Fig. 1 shows the number of RM patients characterised by type: pacemaker (PM), implantable cardiac defibrillator (ICD) and loop recorder (LR). The number of RM patients has substantially increased in the months following the start of the pandemic. Moreover, during the 13 months observation period, hospital visits decreased by an average of 42%, excluding the period July–August 2021, during which no scheduled follow–up visits in our centre are performed (Fig. 2).

Discussion

Our RM activity, which started only for ICD and LR patients, was extended since March 2020 to PM patients, increasing from 125 to 768 MR patients. This has reduced the time spent by the patient and the caregiver in travelling to the hospital, attending for the visit. As a consequence, also the consumption of healthcare resources accordingly decreased, as documented by the 42% reduction in hospital visits. This result was achieved through the setting up of a multi–professional working group (doctor, nurses, biomedical engineer) dedicated to the daily management of incoming transmissions and phone interviews.