bluuebunny/crossref_metadata_2025 huggingface dataset:
Cortical signatures of auditory looming bias show cue-specific adaptation between newborns and young adults
Authors: Ignatiadis Karolina , Baier Diane , Barumerli Roberto , Sziller István , Tóth Brigitta , Baumgartner Robert
Published: June 2024

Adaptive biases in favor of approaching, or “looming”, sounds have been found across ages and species, thereby implicating the potential of their evolutionary origin and universal basis. The human auditory system is well-developed at birth, yet spatial hearing abilities further develop with age. To disentangle the speculated inborn, evolutionary component of the auditory looming bias from its learned counterpart, we collected high-density electroencephalographic data across human adults and newborns. As distance-motion cues we manipulated either the sound’s intensity or spectral shape, which is pinna-induced and thus prenatally inaccessible. Through cortical source localisation we demonstrated the emergence of the bias in both age groups at the level of Heschl’s gyrus. Adults exhibited the bias in both attentive and inattentive states; yet differences in amplitude and latency appeared based on attention and cue type. Contrary to the adults, in newborns the bias was elicited only through manipulations of intensity and not spectral cues. We conclude that the looming bias comprises innate components while flexibly incorporating the spatial cues acquired through lifelong exposure.
Thianthrenation-promoted photoinduced alkene difunctionalization and aryl allylation with Morita–Baylis–Hillman adducts
Authors: Mondal Biplab , Chatterjee Ayan , Saha Nitis Chandra , Jana Manoranjan , Saha Jaideep
Published: June 2024

An organophotoredox-catalyzed alkoxyallylation of feed-stock olefins, through thianthrenation using a Morita–Baylis–Hillman adduct as an allylating agent, is described.
Gold(i)-catalyzed homologation of aryl aldehydes with trimethylsilyldiazomethane
Authors: Bakhoda Abolghasem ‘Gus’
Published: June 2024

A methodology is described herein for the synthesis of 2-aryl acetaldehydes from aryl aldehydes using TMSCHN2 under Au(i) catalysis.
Prebiotic synthesis of dihydrouridine by photoreduction of uridine in formamide
Authors: Xu Jianfeng , Janicki Mikołaj J. , Szabla Rafał , Sutherland John D.
Published: June 2024

UV irradiation of mixtures of canonical ribonucleosides (C, U, A, G) leads to a mixture of dihydrouridine (DHU, modified nucleoside in tRNA) with all four RNA canonical nucleosides (C, U, A, G).
Phosphine-catalyzed (3+3) annulation of cinnamaldehyde-derived Morita–Baylis–Hillman carbonates with dinucleophiles
Authors: Ren Yue , Shi Wangyu , Tang Yi , Guo Hongchao
Published: June 2024

The phosphine-catalyzed (3+3) annulation of cinnamaldehyde-derived Morita–Baylis–Hillman carbonates with 1,3-dicarbonyl compounds as dinucleophiles gave hexahydrochromenone derivatives.
Boosting pollutant degradation with simultaneous H2O2 production from its electron delocalization and excitation co-triggered by microelectric field and visible light
Authors: Chen Zhihong , Pan Yilin , Zhang Xiaohan , Zhang Peng , Hu Chun
Published: June 2024

With the assistance of visible-light, MEF directly used pollutant energy to generate H2O2 and enhance removal, giving a new idea for pollutant resource recovery.
Concluding remarks: biocatalysis
Authors: Bornscheuer Uwe T.
Published: June 2024

The classes of compounds accessible via biocatalysis are as diverse as the concepts to make them, as presented at the Faraday Discussion on biocatalysis.
Metal ion attachment in cavities of metal organic polyhedra to enhance framework robustness and catalytic performance
Authors: Zhu Mengyu , Chen Hang , Li Hairong , Zhang Hao , Liu Lizhen , Hong Qichen , Yao Zizhu , Wang Lihua , Zhang Zhangjing
Published: June 2024

By adjusting the auxiliary ligands, the selective attachment of hydrated copper ions to the cage of metal organic polyhedra (MOP) was achieved. The introduction of hydrated metal ions improved the robustness and catalytic performance of MOPs.
Recent advances of optical fiber biosensors based on surface plasmon resonance: sensing principles, structures, and prospects
Authors: Lv Jingwei , Wang Jianxin , Yang Lin , Liu Wei , Fu Haihao , Chu Paul K. , Liu Chao
Published: June 2024

In this review, recent advances in fiber-optic biosensors based on the SPR phenomenon are summarized. The future development of SPR fiber optic biosensors is expected to identifying significant limitations and meeting specific requirements.
Fabricating mesoscale polymer ribbons with tunable mechanical properties via evaporative deposition and dewetting
Authors: Meissner Cornelia , Bhamla M. Saad , Emrick Todd , Crosby Alfred J.
Published: June 2024

Synthetic replication of the precise mesoscale control found in natural systems poses substantial experimental challenges due to the need for manipulation across multiple length scales (from nano- to millimeter).
Computational single-cell methods for predicting cancer risk
Authors: Teschendorff Andrew E.
Published: June 2024

Despite recent biotechnological breakthroughs, cancer risk prediction remains a formidable computational and experimental challenge. Addressing it is critical in order to improve prevention, early detection and survival rates. Here, I briefly summarize some key emerging theoretical and computational challenges as well as recent computational advances that promise to help realize the goals of cancer-risk prediction. The focus is on computational strategies based on single-cell data, in particular on bottom-up network modeling approaches that aim to estimate cancer stemness and dedifferentiation at single-cell resolution from a systems-biological perspective. I will describe two promising methods, a tissue and cell-lineage independent one based on the concept of diffusion network entropy, and a tissue and cell-lineage specific one that uses transcription factor regulons. Application of these tools to single-cell and single-nucleus RNA-seq data from stages prior to invasive cancer reveal that they can successfully delineate the heterogeneous inter-cellular cancer-risk landscape, identifying those cells that are more likely to turn cancerous. Bottom-up systems biological modeling of single-cell omic data is a novel computational analysis paradigm that promises to facilitate the development of preventive, early detection and cancer-risk prediction strategies.
An orchestrated IoT‐based blockchain system to foster innovation in agritech
Authors: Tasic Igor , Cano Maria‐Dolores
Published: June 2024

Agritech uses advanced technologies to boost the efficiency, sustainability, and productivity of farming. The Internet of Things (IoT) in agriculture has brought sensors and networked technology to gather and analyse environmental and crop data, enabling precision farming that optimises resource usage and increases yields. Yet, current agricultural methods suffer from unsecured and decentralised data management, causing inefficiencies and complicating traceability across the supply chain. The integration of IoT with blockchain technology is seen as a promising solution to enhance data‐driven agriculture. Blockchain provides a secure, decentralised, and transparent ledger that enhances data integrity, reduces fraud, and improves traceability, which complements IoT applications. The authors detail the development of an innovative system that orchestrates IoT and blockchain technologies to facilitate the adoption of new technologies in agriculture and overcomes the lacked of comprehensive data connectivity. It outlines a conceptual framework and its preliminary empirical implementation. The system consists of three integrated layers: the IoT layer, which creates digital twins of field crops; the blockchain layer, which secures and manages data from the field and external stakeholders for dynamic applications such as track and tracing; and the orchestration layer, which fuses physical and digital data to optimise business models, enhance supply chain productivity, and support governmental policy‐making, thereby improving field productivity and food sector innovation.
4D foetal cardiac ultrasound image detection based on deep learning with weakly supervised localisation for rapid diagnosis of evolving hypoplastic left heart syndrome
Authors: Wang Gang , Li Weisheng , Zhou Mingliang , Zhu Haobo , Yang Guang , Yap Choon Hwai
Published: June 2024

Hypoplastic left heart syndrome (HLHS) is a rare, complex, and incredibly foetal congenital heart disease. To decrease neonatal mortality, evolving HLHS (eHLHS) in pregnant women should be critically diagnosed as soon as possible. However, diagnosis is currently heavily dependent on skilled medical professionals using foetal cardiac ultrasound images, making it difficult to rapidly and easily examine for this disease. Herein, the authors propose a cost‐effective deep learning framework for rapid diagnosis of eHLHS (RDeH), which we have named RDeH‐Net. Briefly, the framework implements a coarse‐to‐fine two‐stage detection approach, with a structure classification network for 4D human foetal cardiac ultrasound images from various spatial and temporal domains, and a fine detection module with weakly‐supervised localisation for high‐precision nidus localisation and physician assistance. The experiments extensively compare the authors’ network with other state‐of‐the‐art methods on a 4D human foetal cardiac ultrasound image dataset and show two main benefits: (1) it achieved superior average accuracy of 99.37% on three categories of foetal ultrasound images from different cases; (2) it demonstrates visually fine detection performance with weakly supervised localisation. This framework could be used to accelerate the diagnosis of eHLHS, and hence significantly lessen reliance on experienced medical physicians.
W‐band single‐layer circularly‐polarised antenna based on compact gap waveguide
Authors: Liu Zheng , Qi Shi‐Shan , Yu Yingrui , Wu Wen
Published: June 2024

A single‐layered W band circularly polarised (CP) antenna array fed by a sequential feeding network using compact gap waveguides (GWs) with reduced pins is presented. The radiating element consists of a pair of cross slots and an open‐ended rectangular cavity integrated into the top metal plate of the GW. A sequential rotation network (SRN) consisting of hybrid groove gap waveguide (GGW) and ridge gap waveguide (RGW) structure is presented. Due to the fact that conventional GWs with multiple rows of pins occupy large lateral size, thus making them difficult to realise a single‐layered CP array fed by SRN. Compared with conventional GW with multiple rows of pins, compact GGW with a single row of pins is deployed here to make the presented SRN more compact, thus combining SRN and multiple CP radiators in the same layer. Particularly, a comprehensive investigation on the choice of the GGW groove depth is carried out. The groove depth is designed carefully such that the electric‐field energy is more confined along the GGW line, and less rows of pins are required. For proof‐of‐concept demonstration, the proposed array has been fabricated and measured, exhibiting an overlapped bandwidth of 10.64% (89–99 GHz) and a peak gain of 19.48 dBi at 94 GHz. It presents a promising candidate for W band wireless applications.
Multichannel Wiener filter in active sound‐navigation‐and‐ranging systems—A joint beamformer and matched filter approach
Authors: Kaulen Bastian , Abshagen Jan , Schmidt Gerhard
Published: June 2024

Conventional active SONAR systems often use beamformers and matched filters separately to extract bearing and range information from the received signal and offer a straightforward way of creating a two‐dimensional map of the environment. In SONAR systems the minimum‐variance‐distortionless‐response beamformer (MVDR beamformer) is a commonly used type of beamformer, which will reconstruct the receive signal from a certain direction optimally. In terms of detecting the transmit signal, the most used method is the conventional matched filter. Both algorithms are simple to implement and perform well under various noise scenarios. The proposed method combines the beamformer and matched filter by introducing an extended channel model that allows the derivation of a multichannel Wiener filter to solve for the unknown reflection coefficients of the complete two‐dimensional environment. This results in adaptively calculated filter weights that will drastically improve the performance compared to a separate MVDR beamformer and matched filter. In addition, a parameter is introduced with which one can arbitrarily adjust the focus between angular and temporal resolution depending on the application. After the derivation, the performance is demonstrated with simulations and measurements.
Revealing the potential role of hub metabolism‐related genes and their correlation with immune cells in acute ischemic stroke
Authors: Zhang Xianjing , Xu Tengxiao , Wang Chen , Lin Yueyue , Hu Weimi , Yue Maokui , Li Hao
Published: June 2024

Objectives

Acute ischemic stroke (AIS) is caused by cerebral ischemia due to thrombosis in the blood vessel. The purpose of this study is to identify key genes related to metabolism to aid in the mechanism research and management of AIS.

Materials and Methods

Gene expression data were downloaded from the Gene Expression Omnibus database. Weighted gene co‐expression network analysis, Gene Ontology and kyoto encyclopedia of genes and genomes analysis were used to identify metabolism‐related genes that may be involved in the regulation of AIS. A protein protein interaction network was mapped using Cytoscape based on the STRING database. Subsequently, hub metabolism‐related genes were identified based on Cytoscape‐CytoNCA and Cytoscape‐MCODE plug‐ins. Least absolute shrinkage and selection operator algorithm and differential expression analysis. In addition, drug prediction, molecular docking, ceRNA network construction, and correlation analysis with immune cell infiltration were performed to explore their potential molecular mechanisms of action in AIS. Finally, the expression of hub gene was verified by real‐time PCR.

Results

Metabolism‐related genes FBL, HEATR1, HSPA8, MTMR4, NDUFC1, NDUFS8 and SNU13 were identified. The AUC values of FBL, HEATR1, HSPA8, MTMR4, NDUFS8 and SNU13 were all greater than 0.8, suggesting that they had good diagnostic accuracy. Correlation analysis found that their expression levels were also related to the infiltration levels of multiple immune cells, such as Activated.CD8.T.cell and Activated.dendritic.cell. It was found that only HSPA8 was successfully matched to drugs with literature support, and these drugs were acetaminophen, bupivacaine, dexamethasone, gentamicin, tretinoin and cisplatin. Moreover, it was also identified that the ENSG000000218510‐hsa‐miR‐330‐3p‐HEATR1 axis may be involved in regulating AIS.

Conclusions

The identification of FBL, HEATR1, HSPA8, MTMR4, NDUFC1, NDUFS8 and SNU13 provides a new research direction for exploring the molecular mechanisms of AIS, which can help in clinical management and diagnosis.
Optimising multi‐user wireless networks through discrete Fourier transform‐based channel estimation with cascaded intelligent reflecting surfaces
Authors: Monga Sakhshra , Saluja Nitin , Prabha Chander , Garg Roopali , Bairagi Anupam Kumar , Hassan Md. Mehedi
Published: June 2024

Wireless communication systems are inherently challenged by factors such as fading, path loss, and shadowing, leading to potential errors in data transmission. Traditional methods to mitigate these issues include power control, diversification, variable beamforming, and modulation techniques. However, the unpredictable nature of the wireless medium often limits their effectiveness. A new approach to address these challenges is the implementation of cascaded intelligent reflecting surfaces (IRS). IRS systems consist of multiple passive elements that intelligently reflect electromagnetic waves, thereby enhancing signal quality. The Advanced Discrete Fourier Transform (ADFT) matrix scheme is explored in channel estimation, a novel method particularly suitable for wireless networks utilising cascaded IRS. The ADFT matrix scheme is significant for its efficiency in managing the common‐link configuration of cascading channel coefficients, which effectively reduces pilot overhead. When compared to traditional channel estimation methods like the Least Square|least squares, Maximal a posteriori probability, and Linear Minimum Mean Square Error, the ADFT matrix scheme exhibits superior performance. It achieves a remarkable reduction in normalised mean squared error (NMSE) – 66% and 80% at 20 dB and 15 dB Signal to‐Noise Ratios (SNR), respectively. Furthermore, increasing the pilot length correlates with enhanced NMSE performance, with a noted 33% improvement as the base station distance increases. Simulations demonstrate that with an escalation in the number of IRS elements and SNR, the ADFT matrix scheme consistently surpasses conventional methods. This advancement represents a significant leap in the field of wireless communication technology.
Particle acceleration, escape, and non-thermal emission from core-collapse supernovae inside non-identical wind-blown bubbles
Authors: Das Samata , Brose Robert , Pohl Martin , Meyer Dominique M.-A. , Sushch Iurii
Published: June 2024

Context.In the core-collapse scenario, supernova remnants (SNRs) evolve inside complex wind-blown bubbles structured by massive progenitors during their lifetime. Therefore, particle acceleration and the emissions from these SNRs can carry the fingerprints of the evolutionary sequences of the progenitor stars.

Aims.We investigate the impact of the ambient environment of core-collapse SNRs on particle spectra and emissions for two progenitors with different evolutionary tracks while accounting for the spatial transport of cosmic rays (CRs) and the magnetic turbulence that scatters CRs.

Methods.We used theRATPaCcode to model the particle acceleration at the SNRs with progenitors having zero-age main sequence (ZAMS) masses of 20M⊙and 60M⊙. We constructed the pre-supernova circumstellar medium (CSM) by solving the hydrodynamic equations for the lifetime of the progenitor stars. Then, the transport equation for cosmic rays, the magnetic turbulence in test-particle approximation, and the induction equation for the evolution of a large-scale magnetic field were solved simultaneously with the hydro-dynamic equations for the expansion of SNRs inside the pre-supernova CSM in 1-D spherical symmetry.

Results.The profiles of gas density and temperature of the wind bubbles along with the magnetic field and the scattering turbulence regulate the spectra of accelerated particles for both of the SNRs. For the 60M⊙progenitor, the spectral index reaches 2.4, even below 10 GeV, during the propagation of the SNR shock inside the hot shocked wind. In contrast, we did not observe a persistent soft spectra at earlier evolutionary stages of the SNR with the 20M⊙progenitor, for which the spectral index becomes 2.2 only for a brief period during the interaction of SNR shock with the dense shell of red supergiant (RSG) wind material. At later stages of evolution, the spectra become soft above ~10 GeV for both SNRs, as weak driving of turbulence permits the escape of high-energy particles from the remnants. The emission morphology of the SNRs strongly depends on the type of progenitors. For instance, the radio morphology of the SNR with the 20M⊙progenitor is centre-filled at early stages, whereas that of the more massive progenitor is shell-like.
How informative are summaries of the cosmic 21 cm signal?
Authors: Prelogović David , Mesinger Andrei
Published: June 2024

The cosmic 21 cm signal will bring data-driven advances to studies of Cosmic Dawn (CD) and the Epoch of Reionization (EoR). Radio telescopes such as the Square Kilometre Array (SKA) will eventually map the HI fluctuations over the first billion years – the majority of our observable Universe. With such large data volumes, it becomes increasingly important to develop “optimal” summary statistics, which will allow us to learn as much as possible about the CD and EoR. In this work we compare the astrophysical parameter constraining power of several 21 cm summary statistics, using the determinant of the Fisher information matrix, detF. Since we do not have an established “fiducial” model for the astrophysics of the first galaxies, we computed for each summary the distribution of detFacross the prior volume. Using a large database of cosmic 21 cm light cones that include realizations of telescope noise, we compared the following summaries: (i) the spherically averaged power spectrum (1DPS), (ii) the cylindrically averaged power spectrum (2DPS), (iii) the 2D wavelet scattering transform (WST), (iv) a recurrent neural network (RNN) trained as a regressor; (v) an information-maximizing neural network (IMNN); and (vi) the combination of 2DPS and IMNN. Our best performing individual summary is the 2DPS, which provides relatively high Fisher information throughout the parameter space. Although capable of achieving the highest Fisher information for some parameter choices, the IMNN does not generalize well, resulting in a broad distribution across the prior volume. Our best results are achieved with the concatenation of the 2DPS and IMNN. The combination of only these two complimentary summaries reduces the recovered parameter variances on average by factors of ∼6.5–9.5, compared with using each summary independently. Finally, we point out that that the common assumption of a constant covariance matrix when doing Fisher forecasts using 21 cm summaries can significantly underestimate parameter constraints.
Croissance et développement dento-cranio-facial chez des jumeaux monozygotes
Authors: Benoît Roland , Falque Elisabeth
Published: June 2024

L’étude du développement, chez des jumeaux, montrent des diversités dans leur croissance et développement. L’axe de développement est un instrument qui caractérise ces croissances. Le travail de recherche a particulièrement révélé l’axe de développement de 30°. Pour compléter cette recherche, il est utile de multiplier le nombre de patients.
A comparison of novel electrocautery-enhanced lumen-apposing metal stents and plastic stents in endoscopic ultrasound-guided drainage of infected walled-off necrosis: a multicenter randomized study
Authors: Moon Jong Ho , Park Se Woo , Lee Yun Nah , Lee Sang Hyub , Kim Seong-Hun , Lee Dong Wook , Cho Chang Min , Kim Sung Bum , Park Chan Hyuk
Published: June 2024

Background Although lumen-apposing metal stents (LAMSs) have been increasingly used for walled-off necrosis (WON), their advantages over plastic stents in infected WON are unclear. We investigated the safety and efficacy of a novel electrocautery-enhanced LAMS for managing infected WON.

Methods Patients who required endoscopic ultrasound-guided WON drainage were randomly assigned to LAMS or plastic stent groups. The primary outcome was total number of direct endoscopic necrosectomy (DEN) procedures required to achieve clinical success. Secondary outcomes included rates of technical success, clinical success, and adverse events.

Results 46 patients were included in the LAMS (n = 23) and plastic stent (n = 23) groups. The median total number of DEN procedures did not differ significantly between the plastic stent group (4 procedures, interquartile range [IQR] 2.5–5.0) and LAMS group (9 procedures, IQR 8.0–9.0) (P = 0.07). The LAMS group demonstrated a significantly higher clinical success rate than the plastic stent group based on intention-to-treat analysis (100% vs. 73.9%, P =0.03) at 8 weeks but not at 4 weeks. Significant bleeding occurred in one patient in the plastic stent group and no patients in the LAMS group.

Conclusions We found no significant difference in the total number of DEN procedures between LAMSs and plastic stents for managing infected WON. The only statistically significant finding was a higher clinical success rate at 8 weeks for patients treated with LAMS. The use of LAMS did not result in any adverse events, such as bleeding or buried LAMS syndrome, within the study duration.
Biomechanical Profile after Dry Needling in Mixed Martial
Arts
Authors: Trybulski Robert , Kużdżał Adrian , Stanula Arkadiusz , Klich Sebastian , Clemente Filipe Manuel , Kawczyński Adam , Fernández-de-las-Peñas Cesar
Published: June 2024

The purpose of this study was to compare the effects of dry needling (DN)
intervention on the responses of muscle tone, stiffness, and elasticity, as well
as power, pressure pain thresholds, and blood perfusion of the flexor carpi
radialis muscle in mixed martial arts (MMA) athletes. Thirty-two
trained/developmental men MMA fighters (25.5±4.5 years; 24.5±3 body mass index)
participated in a randomized crossover study. Participants underwent a single
intervention, receiving both DN and placebo. Laser Doppler flowmetry measured
blood perfusion, while a myotonometer assessed the mechanical characteristics of
muscle tone, stiffness, and elasticity of the flexor carpi radialis muscle.
Pressure pain thresholds (PPT) were measured using an algometer, and maximal
forearm muscle force was measured using a hand dynamometer. Outcomes were
assessed at baseline, immediately after, and 24 hours and 48 hours
post-intervention. A two-way repeated-measures ANOVA revealed significant
Intervention*Time interaction for all outcomes: perfusion unit
(p<0.001), muscle tone (p<0.001), stiffness (p<0.001),
elasticity (p<0.001), PPT (p<0.001) and maximal forearm
muscle force (p<0.001). The current study suggests that a single
session of DN enhances muscle recovery, increases muscle strength, and improved
PPT in MMA athletes. These positive adaptations appear to last up to 48 hours in
some variables.
Pregnancy Outcomes after Uterine Preservation Surgery for Placenta Accreta Spectrum: A Retrospective Cohort Study
Authors: Ohayon Aviran , Castel Elias , Friedrich Lior , Mor Nitzan , Levin Gabriel , Meyer Raanan , Toussia-Cohen Shlomi
Published: June 2024

Objective This study aimed to investigate maternal and neonatal outcomes in subsequent pregnancies of women with a history of placenta accreta spectrum (PAS) compared with women without history of PAS.

Study Design A retrospective cohort study conducted at a single tertiary center between March 2011 and January 2022. We compared women with a history of PAS who had uterine preservation surgery and a subsequent pregnancy, to a control group matched in a 1:5 ratio. The primary outcome was the occurrence of a composite adverse outcome (CAO) including any of the following: uterine dehiscence, uterine rupture, blood transfusion, hysterectomy, neonatal intensive care unit admission, and neonatal mechanical ventilation. Multivariable logistic regression was performed to evaluate associations with the CAO.

Results During the study period, 287 (1.1%) women were diagnosed with PAS and delivered after 25 weeks of gestation. Of these, 32 (11.1%) women had a subsequent pregnancy that reached viability. These 32 women were matched to 139 controls. There were no significant differences in the baseline characteristics between the study and control groups. Compared with controls, the proportion of CAO was significantly higher in women with previous PAS pregnancy (40.6 vs. 19.4%, p = 0.019). In a multivariable logistic regression analysis, previous PAS (adjusted odds ratio [aOR] = 3.31, 95% confidence interval [CI] = 1.09–10.02, p = 0.034) and earlier gestational age at delivery (aOR = 3.53, 95% CI = 2.27–5.49, p < 0.001) were independently associated with CAOs.

Conclusion A history of PAS in a previous pregnancy is associated with increased risk of CAOs in subsequent pregnancies.

Key Points
Renal Cortical Imaging with Tc-99m DMSA in Children: An Institutional Review
Authors: Hardina Septi , Nugrahadi Trias , Budiawan Hendra , Kartamihardja Achmad Hussein Sundawa
Published: June 2024

Background Urinary tract infection (UTI) is one of the commonly encountered conditions in children. Dimercaptosuccinic acid (DMSA) scintigraphy is widely advocated for functional and morphological evaluation of the renal cortex including parenchymal defect. Moreover, only a small percentage of renal defects are detected by ultrasound. We aimed to examine DMSA scintigraphy of children and identify factors associated with cortical defect.

Methods Patients aged ≤ 18 years old who underwent DMSA scintigraphy (November 18, 2019–February 2, 2023, 30 children) were included. All children received intravenous injections of 99mTc-DMSA followed by static planar and single-photon-emission computed tomography imaging at 3 hours. Cortical findings and differential functions of the worst affected kidney were graded accordingly. Grade I has no more than two cortical defects, grade II has more than two cortical defects with normal parenchyma between the defects, while grade III is when generalized damage is noted, and grade IV is when a shrunken kidney is seen with no DMSA uptake. Normal functioning kidney is when the relative function at 45 to 55%, mildly reduced function at 40 to 44%, and substantially impaired function at 10 to 39%, while nonfunctioning is when the differential split renal function < 10%. All data were then statistically analyzed.

Results Majority was female (53%). The mean age was 5.85 years. UTI episodes were 73%. Twenty-two children had congenital urinary tract anomalies. All patients with vesicoureteric refluxes (VURs) had positive defects. Scintigraphy showed abnormalities in 17 children affecting unilateral (64%) or both kidneys (36%). There were 17 children (57%) respectively in the abnormal DMSA scan findings category with normal until significant impairment of the functioning kidney category. VURs were significantly associated with abnormal scintigraphy (p < 0.05). A significant association was found between abnormal DMSA scan findings and differential renal function (p < 0.05).

Conclusion Significant association was noted between VURs and abnormal DMSA scintigraphy, abnormal DMSA scan findings, and impaired differential renal function. Special consideration should be given to these cases.
Out-of-time ordered correlators in kicked coupled tops: Information scrambling in mixed phase space and the role of conserved quantities
Authors: Varikuti Naga Dileep , Madhok Vaibhav
Published: June 2024

We study operator growth in a bipartite kicked coupled tops (KCTs) system using out-of-time ordered correlators (OTOCs), which quantify “information scrambling” due to chaotic dynamics and serve as a quantum analog of classical Lyapunov exponents. In the KCT system, chaos arises from the hyper-fine coupling between the spins. Due to a conservation law, the system’s dynamics decompose into distinct invariant subspaces. Focusing initially on the largest subspace, we numerically verify that the OTOC growth rate aligns well with the classical Lyapunov exponent for fully chaotic dynamics. While previous studies have largely focused on scrambling in fully chaotic dynamics, works on mixed-phase space scrambling are sparse. We explore scrambling behavior in both mixed-phase space and globally chaotic dynamics. In the mixed-phase space, we use Percival’s conjecture to partition the eigenstates of the Floquet map into “regular” and “chaotic.” Using these states as the initial states, we examine how their mean phase space locations affect the growth and saturation of the OTOCs. Beyond the largest subspace, we study the OTOCs across the entire system, including all other smaller subspaces. For certain initial operators, we analytically derive the OTOC saturation using random matrix theory (RMT). When the initial operators are chosen randomly from the unitarily invariant random matrix ensembles, the averaged OTOC relates to the linear entanglement entropy of the Floquet operator, as found in earlier works. For the diagonal Gaussian initial operators, we provide a simple expression for the OTOC.
Modeling defect-level switching for nonlinear and hysteretic electronic devices
Authors: Dong Jiahao , Jaramillo R.
Published: June 2024

Previously, we demonstrated hysteretic and persistent changes of resistivity in two-terminal electronic devices based on charge trapping and detrapping at immobile metastable defects [Yin et al., Phys. Rev. Appl. 15, 014014 (2021)]; we termed these defect-level switching (DLS) devices. DLS devices feature all-electronic resistive switching and thus are volatile because of the “voltage-time” dilemma. However, the dynamics of volatile resistive switches may be valuable for emerging applications such as selectors in crosspoint memory and neuromorphic computing concepts. To design circuits using these volatile resistive switches, accurate modeling is essential. In this work, we develop an accurate and analytical model to describe the switching in DLS devices, based on the established theories of point defect metastability in Cu(In,Ga)Se2 (CIGS) and II–VI semiconductors. The analytical nature of our model allows for time-efficient simulations of dynamical behavior of DLS devices. We model the time durations of SET and RESET programming pulses, which can be exponentially shortened with respect to the pulse amplitude. We also demonstrate the concept of inverse design: given desired resistance states, the width and amplitude of the programming signal can be chosen accordingly.
Effect of amplitude measurements on the precision of thermal parameters’ determination in GaAs using frequency-resolved thermoreflectance
Authors: Chatterjee Ankur , Dziczek Dariusz , Song Peng , Liu J. , Wieck Andreas. D. , Pawlak Michal
Published: June 2024

Non-contact photothermal pump-probe methodologies such as Frequency-Domain Thermo-Reflectance (FDTR) systems facilitate the examination of thermal characteristics spanning semiconductor materials and their associated interfaces. We underscore the significance of meticulous measurements and precise error estimation attained through the analysis of both amplitude and phase data in Thermo-Reflectance (TR). The precision of the analytical estimation hinges greatly on the assumptions made before implementing the method and notably showcases a decrease in errors when both the amplitude and phase are incorporated as input parameters. We demonstrate that frequency-domain calculations can attain high precision in measurements, with error estimations in thermal conductivity (k), thermal boundary resistance (Rth), and thermal diffusivity (α) as low as approximately 2.4%, 2.5%, and 3.0%, respectively. At the outset, we evaluate the uncertainty arising from the existence of local minima when analyzing data acquired via FDTR, wherein both the phase and amplitude are concurrently utilized for the assessment of cross-plane thermal transport properties. Expanding upon data analysis techniques, particularly through advanced deep learning approaches, can significantly enhance the accuracy and precision of predictions when analyzing TR data across a spectrum of modulation frequencies. Deep learning models enhance the quality of fitting and improve the accuracy and precision of uncertainty estimation compared to traditional Monte Carlo simulations. This is achieved by providing suitable initial guesses for data fitting, thereby enhancing the overall performance of the analysis process.
Strain effect on thermal conductivity of 3C-SiC nanowire
Authors: Chen Wenkang , Wu Xiangshui , Deng Shichen , Yang Nuo , Xu Xiangfan
Published: June 2024

Strain provides an additional mechanism in tuning the thermal/electrical properties of nanostructures and therefore has triggered lots of interest in recent years. However, experimental research about the strain effect on the thermal conductivity of nanowires is still limited, especially in the low-temperature range, which is important in understanding the physics of strain-induced regulation in thermal conductivity. Here, we present thermal transport measurements of bent silicon carbide nanowires at temperatures ranging from 20 to 300 K. Reduction in thermal conductivity compared to their straight counterparts is observed. More specifically, the relative change is up to 55% at 20 K and descends with temperature, which is due to the inhomogeneous strain-induced phonon scattering. This study will deepen the understanding of thermal properties in nanostructures with strain.
Measuring line tension: Thermodynamic integration during detachment of a molecular dynamics droplet
Authors: Shintaku Minori , Oga Haruki , Kusudo Hiroki , Smith Edward R. , Omori Takeshi , Yamaguchi Yasutaka
Published: June 2024

The contact line (CL) is where solid, liquid, and vapor phases meet, and Young’s equation describes the macroscopic force balance of the interfacial tensions between these three phases. These interfacial tensions are related to the nanoscale stress inhomogeneity appearing around the interface, and for curved CLs, e.g., a three-dimensional droplet, another force known as the line tension must be included in Young’s equation. The line tension has units of force, acting parallel to the CL, and is required to incorporate the extra stress inhomogeneity around the CL into the force balance. Considering this feature, Bey et al. [J. Chem. Phys. 152, 094707 (2020)] reported a mechanical approach to extract the value of line tension τℓ from molecular dynamics (MD) simulations. In this study, we show a novel thermodynamics interpretation of the line tension as the free energy per CL length, and based on this interpretation, through MD simulations of a quasi-static detachment process of a quasi-two-dimensional droplet from a solid surface, we obtained the value τℓ as a function of the contact angle. The simulation scheme is considered to be an extension of a thermodynamic integration method, previously used to calculate the solid–liquid and solid–vapor interfacial tensions through a detachment process, extended here to the three-phase system. The obtained value agreed well with the result by Bey et al. and showed the validity of thermodynamic integration at the three-phase interface.
Characterization of an RF-excited broad beam ion source operated with a mixture of CHF3 and O2
Authors: Rohkamm Erik , Spemann Daniel , Scholze Frank , Frost Frank
Published: June 2024

The composition and ion energy distributions of the main ion species of an ion beam were recorded and analyzed. The RF-type broad beam ion source was operated with a mixture of CHF3 and O2. A plasma bridge neutralizer operating with Ar was employed for ion beam neutralization. The data were collected with an energy-selective mass spectrometer (ESMS). The mass spectrum showed numerous ion species, beginning with ionized molecules, dissociation products of the process gases and products from reactions with background gas and the plasma discharge vessel, and the extraction system. For a quantification of the ion beam composition, the mass dependent transmission functions for two ESMS were determined. The ion energy distributions show that, in comparison to operation with inert gases, there are additional slower ions present. These ions can be related to dissociation processes outside of the ion beam source. As a result of their typically lower etching yield, these slower ions affect the etching behavior.
Exciton–photocarrier interference in mixed lead-halide-perovskite nanocrystals
Authors: Rojas-Gatjens Esteban , Akkerman Quinten A. , Manna Liberato , Srimath Kandada Ajay Ram , Silva-Acuña Carlos
Published: June 2024

The use of semiconductor nanocrystals in scalable quantum technologies requires characterization of the exciton coherence dynamics in an ensemble of electronically isolated crystals in which system–bath interactions are nevertheless strong. In this communication, we identify signatures of Fano-like interference between excitons and photocarriers in the coherent two-dimensional photoluminescence excitation spectral lineshapes of mixed lead-halide perovskite nanocrystals in dilute solution. Specifically, by tuning the femtosecond-pulse spectrum, we show such interference in an intermediate coupling regime, which is evident in the coherent lineshape when simultaneously exciting the exciton and the free-carrier band at higher energy. We conclude that this interference is an intrinsic effect that will be consequential in the quantum dynamics of the system and will thus dictate decoherence dynamics, with consequences in their application in quantum technologies.
Quantum chemical calculations of electron affinities of alkaline earth metal atoms (Ca, Sr, Ba, and Ra)
Authors: Park Eunji , Park Jeongmin , Kim Ingyeong , Kim Jungyoon , Seo Wonil , Yadav Rajesh K. , Kim Joonghan
Published: June 2024

We performed high-level ab initio quantum chemical calculations, incorporating higher-order excitations, spin–orbit coupling (SOC), and the Gaunt interaction, to calculate the electron affinities (EAs) of alkaline earth (AE) metal atoms (Ca, Sr, Ba, and Ra), which are notably small. The coupled-cluster singles and doubles with perturbative triples [CCSD(T)] method is insufficient to accurately calculate the EAs of AE metal atoms. Higher-order excitations proved crucial, with the coupled-cluster singles, doubles, and triples with perturbative quadruples [CCSDT(2)Q] method effectively capturing dynamic electron correlation effects. The contributions of SOC (ΔESOs) to the EAs calculated using the multireference configuration interaction method with the Davidson correction, including SOC, positively enhance the EAs; however, these contributions are overestimated. The Dirac–Hartree–Fock (DHF)-CCSD(T) method addresses this overestimation and provides reasonable values for ΔESO (ΔESO−D). Employing additional sets of diffuse and core–valence correlation basis sets is critical for accurately calculating the EAs of AE metal atoms. The contributions of the Gaunt interaction (ΔEGaunt) to the EAs of AE metal atoms are negligible. Notably, the CCSDT(2)Q with the complete basis set limit + ΔESO−D + ΔEGaunt produced EA values for Ca, Sr, and Ba that closely aligned with experimental data and achieved accuracy exceeding the chemical accuracy. Based on our findings, the accurately proposed EA for Ra is 9.88 kJ/mol.
Excessive charge, beam loading, and impedance collapse thresholds for a velvet emitter
Authors: Coleman J. E. , Howard M. R.
Published: June 2024

Excess emission has been observed from velvet cathodes with total emission times >150 ns. In this diode experiment, we produce a sub-relativistic electron beam with the ability to consistently change γ from 1.2 to 1.5 and β = 0.5–0.75. Electron emission in this particular diode geometry requires electric fields >40 kV/cm. The current increases at steady rates >0.05 A/ns after the head of the pulse, indicating an expansion of the emission surface and reduction in the effective AK gap. Small transients of excess emission (or arcs) are consistently observed for current pulses exceeding 150 ns. The excess emission results in beam loaded levels ≥10 kV on the diode voltage. The effects described here are compounded as diode voltage is increased. The principal objective of these experiments is to quantify electric field emission thresholds, current ramps, excess emission delays, effective beam loading, and impedance collapse.
Effectively detecting cardiac myoglobin by use of bound states in the continuum in silicon nitride gratings
Authors: Beliaev Leonid Yu. , Takayama Osamu , Xiao Sanshui
Published: June 2024

Optical biosensors with their sensitivity, compact design, and reliability stand out as versatile tools capable of detecting a wide range of analytes. Recently, nanophotonic structures supporting bound states in the continuum (BIC) modes have been actively studied, which is especially interesting for biosensing applications due to their high quality (Q) factor and strongly localized electric field, achieving favorable interaction between field and nanometer scale analyte on the sensing surface. Herein, we demonstrate an optical label-free sensing by accidental or Friedrich–Wintgen (FW) BIC supported on silicon nitride gratings. We compared the sensing performance in terms of bulk, and surface sensitivity, and figure of merit with FW-BIC in the leaky regime and with a symmetry-protected (SP) BIC, which are also supported by the studied platform. We exploit the fact that for FW-BIC a high-Q factor up to 498 comparable to that of SP-BIC (up to 425) retains for a much larger set of interrogation angles, providing excellent interrogation stability. We observed that FW-BIC has slightly higher bulk sensitivity than SP-BIC [186 and 158 nm/RIU (refractive index unit), respectively], but at the same time similar characteristics in terms of surface sensitivity and figure of merit. In addition, we show that both BIC resonances are significantly superior in all respects to the leaky regime due to better field confinement. Finally, the surface of sensing device was also functionalized to detect a cardiac biomarker, myoglobin, exhibiting the limit of detection of 49 ng/ml with clinically relevant level.
Inductive detection of temperature-induced magnetization dynamics of molecular spin systems
Authors: Melnikov Anatoly R. , Ivanov Mikhail Yu. , Samsonenko Arkady A. , Getmanov Yaroslav V. , Nikovskiy Igor A. , Matiukhina Anna K. , Zorina-Tikhonova Ekaterina N. , Voronina Julia K. , Goloveshkin Alexander S. , Babeshkin Konstantin A. , Efimov Nikolay N. , Kiskin Mikhail A. , Eremenko Igor L. , Fedin Matvey V. , Veber Sergey L.
Published: June 2024

The development and technological applications of molecular spin systems require versatile experimental techniques to characterize and control their static and dynamic magnetic properties. In the latter case, bulk spectroscopic and magnetometric techniques, such as AC magnetometry and pulsed electron paramagnetic resonance, are usually employed, showing high sensitivity, wide dynamic range, and flexibility. They are based on creating a nonequilibrium state either by changing the magnetic field or by applying resonant microwave radiation. Another possible source of perturbation is a laser pulse that rapidly heats the sample. This approach has proven to be one of the most useful techniques for studying the kinetics and mechanism of chemical and biochemical reactions. Inspired by these works, we propose an inductive detection of temperature-induced magnetization dynamics as applied to the study of molecular spin systems and describe the general design and construction of a particular induction probehead, taking into account the constraints imposed by the cryostat and electromagnet. To evaluate the performance, several coordination compounds of VO2+, Co2+, and Dy3+ were investigated using low-energy pulses of a terahertz free electron laser of the Novosibirsk free electron laser facility as a heat source. All measured magnetization dynamics were qualitatively or quantitatively described using a proposed basic theoretical model and compared with the data obtained by alternating current magnetometry. Based on the results of the research, the possible scope of applications of inductive detection and its advantages and disadvantages in comparison with standard methods are discussed.
Influence of swelling on the elasticity of polymer networks cross-linked in the melt state: Test of the localization model of rubber elasticity
Authors: Douglas Jack F. , Horkay Ferenc
Published: June 2024

The elasticity of polymer networks, formed by cross-linking high molecular mass polymers in the melt state and then swollen by a solvent, involves contributions from both the presence of cross-link network junctions and the interchain interactions associated with the combined effect of excluded volume interactions and topological constraints that become modified when the network is swollen. We test the capacity of the previously developed localization model of rubber elasticity, a mean field “tube model,” to describe changes in elasticity observed in classical experimental studies of the mechanical properties of this type of network. In order to obtain a satisfactory comparison to the experiments, it was found to be necessary to account for the independently observed tendency of the network junctions to become localized in the network with appreciable swelling, as well as the interchain interactions emphasized in previous discussions of the localization model.