bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast and Reversible Quasi‐Solid‐State Anion Exchange in Highly Luminescent CsPbX3 Perovskite Nanocrystals for Dual‐Mode Encryption–Decryption
Authors: Lai Yueling , Zhou Yufeng , Liu Hongjiang , Guo Tongyin , Zou Anqi , Wang Lianju , Chen Yiqing , Zhao Xianglong , Zheng Kanghui , Tong Xin , Wang Ruilin
Published: August 2023

Solid‐state anion exchange method is easy to handle and beneficial to improve stability of CsPbX3 (X = Cl, Br, I) perovskites nanocrystals (NCs) with respect to anion exchange in liquid phase. However, the corresponding exchange rate is rather slow due to the limited diffusion rate of anions from solid phases, resulting in mixed‐halide perovskite NCs. Herein,  a fast and reversible post‐synthetic quasi‐solid‐state anion exchange method in CsPbX3 NCs with inorganic potassium halide KX salts/polyvinylpyrrolidone (PVP) thin film is firstly reported. Original morphology of the exchanged NCs is well‐preserved for all samples. Complete anion exchange from Br− to Cl− or I− is successfully achieved in CsPbX3 NCs within ≈20 min through possible vacancies‐assisted ion exchange mechanism, under ambient conditions and vice versa. Particularly, Br−‐exchanged CsPbCl3 and CsPbI3 NCs exhibit improved optical properties. Encouraged by the attractive fluorescence and persistent luminescence as well as good stability of the resulted CsPbX3 NCs, an effective dual‐mode information storage–reading application is demonstrated.  It is believed that this method can open a new avenue for the synthesis of other direct‐synthesis challenging quantum‐confined perovskite NCs/nanoplates/nanodisks or CsSnX3 NCs/thin film and provide an opportunity for advanced information storage compatible for practical applications.
Anchoring Polar Organic Molecules in Defective Ammonium Vanadate for High‐Performance Flexible Aqueous Zinc‐Ion Battery
Authors: Kong Shuo , Li Yuxin , Zhang Xiaojie , Xu Ziming , Wang Xianzhen , Feng Yongbao , Gong Wenbin , Liu Chenglong , Tian Konghu , Li Qiulong
Published: August 2023

Ammonium vanadate (NVO) often has unsatisfactory electrochemical performance due to the irreversible removal of NH4+ during the reaction. Herein, layered DMF‐NVO nanoflake arrays (NFAs) grown on highly conductive carbon cloth (CC) are employed as the binder‐free cathode (DMF‐NVO NFAs/CC), which produces an enlarged interlayer spacing of 12.6 Å (against 9.5 Å for NH4V4O10) by effective N, N‐dimethylformamide (DMF) intercalation. Furthermore, the strong attraction of highly polar carbonyl and ammonium ions in DMF can stabilize the lattice structure, and low‐polar alkyl groups can interact with the weak electrostatic generated by Zn2+, which allows Zn2+ to be freely intercalated. The DMF‐NVO NFAs/CC//Zn battery exhibits an impressive high capacity of 536 mAh g−1 at 0.5 A g−1, excellent rate capability, and cycling performance. The results of density functional theory simulation demonstrate that the intercalation of DMF can significantly reduce the band gap and the diffusion barrier of Zn2+, and can also accommodate more Zn2+. The assembled flexible aqueous rechargeable zinc ion batteries (FARZIBs) exhibit outstanding energy density and power density, up to 436 Wh kg−1 at 400 W kg−1, and still remains 180 Wh kg−1 at 4000 W kg−1. This work can provide a reference for the design of cathode materials for high‐performance FARZIBs.
Rapid Yet Efficient Reduction of Graphene Oxide Triggered by Semi‐Molten Metals
Authors: Liu Jianpeng , Zhang Wenchang , Cheng Chang , Zhu Juncheng , Wang Tianle , Ni Kun , Lin Zifeng , Guan Zefeng , Zhu Yanwu , Zhu Jiliang
Published: August 2023

Reduced graphene oxide (rGO) has garnered extensive attention as electrodes, sensors, and membranes, necessitating the efficient reduction of graphene oxide (GO) for optimal performance. In this work, a swift reduction of GO that involves bringing GO foam in contact with semi‐molten metals like tin (Sn) and lithium (Li) is presented. These findings reveal that the electrical resistance of GO foam is significantly diminished by its interaction with these metals, even in dry air. Taking inspiration from this technique, Sn foil is employed to encase the GO foam, followed by a calcination in 15 vol% H2/Ar environment at 235 °C to fabricate the rGO, which demonstrates a remarkably lower electrical resistivity of 0.42 Ω cm when compared to the chemically reduced GO via hydrazine hydrate (650 Ω cm). The reduction mechanism entails the migration of Sn on GO and its subsequent reaction with oxygen functional groups. SnO/Sn(OH)2 formed from the reaction can be subsequently reversed through reduction by H2 to Sn. Utilizing this rGO as the host material for a sulfur cathode, a lithium–sulfur battery is constructed that displays a specific capacity of 1146 mAh g−1 and maintains a capacity retention of 68.4% after 300 cycles at a rate of 0.2 C.
Improving Wettability at Positive Electrodes to Enhance the Cycling Stability of Bi‐Based Liquid Metal Batteries
Authors: Zhou Yan , Ning Xiaohui
Published: August 2023

Liquid metal batteries (LMBs) are promising candidates for grid‐scale energy storage due to their exceptional kinetics, scalability, and long lifespan derived from the distinctive three‐liquid‐layer structure. However, the positive electrode (such as Bi) suffers from insufficient wettability on the current collector, resulting in excess electrical resistance and uneven current distribution, thus deteriorating the cycling stability. Here the incorporation of 4 mol% Se into Bi‐based metal is proposed producing an interface layer with highly surface‐active property that decreases the electrode's contact angle with the 304 stainless‐steel (SUS304) from 144.7° to 74.3°, so as to improve the wettability. The as‐prepared 20 Ah Li || Bi‐Se4 (the content of Se is 4 mol% of Bi) cell cycled 1200 times with capacity fade rate of merely 0.00174% per cycle. This facile and effective approach provides a pathway toward the production of stable cells with an extended lifespan and boosts the practical implementation of LMBs.
In Situ Transmission Electron Microscopy to Study the Location and Distribution Effect of Pt on the Reduction of Co3O4–SiO2
Authors: Tang Min , de Jongh Petra E. , de Jong Krijn P.
Published: August 2023

The addition of Pt generally promotes the reduction of Co3O4 in supported catalysts, which further improves their activity and selectivity. However, due to the limited spatial resolution, how Pt and its location and distribution affect the reduction of Co3O4 remains unclear. Using ex situ and in situ ambient pressure scanning transmission electron microscopy, combined with temperature‐programmed reduction, the reduction of silica‐supported Co3O4 without Pt and with different location and distribution of Pt is studied. Shrinkage of Co3O4 nanoparticles is directly observed during their reduction, and Pt greatly lowers the reduction temperature. For the first time, the initial reduction of Co3O4 with and without Pt is studied at the nanoscale. The initial reduction of Co3O4 changes from surface to interface between Co3O4 and SiO2. Small Pt nanoparticles located at the interface between Co3O4 and SiO2 promote the reduction of Co3O4 by the detachment of Co3O4/CoO from SiO2. After reduction, the Pt and part of the Co form an alloy with Pt well dispersed. This study for the first time unravels the effects of Pt location and distribution on the reduction of Co3O4 nanoparticles, and helps to design cobalt‐based catalysts with efficient use of Pt as a reduction promoter.
Enhanced Photothermal Activity of Nanoconjugated System via Covalent Organic Frameworks as the Springboard
Authors: Liang Hongzhi , Chen Shizhang , Qileng Aori , Liu Weipeng , Xu Zhenlin , Zhang Shengsen , Liu Yingju
Published: August 2023

The development of nanomaterials with high photothermal conversion efficiency has been a hot issue. In this work, a novel photothermal nanomaterial is synthesized using Prussian blue nanocubes (PBNCs) as the photothermal active substance and covalent organic framework (COF) as the substrate. The as‐prepared COF@PBNCs show a high photothermal conversion efficiency of 59.1%, significantly higher than that of pure PBNCs (32.5%). A new circuit path is generated with the combination of COF, which prevents the direct combination of thermal electrons and holes, as well as enhances the nonradiation transition of PBNCs. Besides, the imine groups on COF as the coordination and reduction agent allow the in situ growth of PBNCs, and the dense micropores of COF as the ideal heat conduction channels can also be the potential factors for the enhanced photothermal property. The photothermal property of COF@PBNCs is further used in the construction of immunosensor for the detection of furosemide (FUR). With the help of handheld thermal imager, the concentration of FUR can be easily read, thus shedding a new light in the construction of visual sensor for simple and low‐cost point‐of‐care testing.
Synergetic Self‐Assembly of Liquid Crystalline Block Copolymer with Amphiphiles for Fabrication of Hierarchical Assemblies
Authors: Lu Yue , Gao Juanjuan , Ren Yangge , Ding Yi , Jia Lin
Published: August 2023

Novel functions and advanced structure, where each single component could not be produced individually, can exhibit from the collective and synergistic behavior of component systems. This synergetic strategy has been successfully demonstrated for co‐assembly of polymer–polymer to construct hierarchical nanomaterials. However, differences in the natures of polymer and small molecules impose challenges in the construction of sophisticated co‐assemblies with geometrical and compositional control. Herein, a synergetic self‐assembly strategy is proposed to prepare organic–organic hybrid colloidal mesostructures by blending a liquid crystalline block copolymer (LC‐BCP) with small molecular amphiphiles. Through a classic solvent‐exchange process, amphiphiles embedded with LC‐BCP realize multi‐component nucleation and hierarchical assembly driven by anisotropic interaction from the LC ordering alignment of the core‐forming block. 1D nanofibers with a periodic striped structure are formed by further LC component fusion and refinement. In addition, LC ordering effect of LC‐BCP can be regulated by selecting appropriate solvents and leads to the formation of vesicular co‐micelles. By means of the thermal‐responsive behavior of amphiphiles, hexagonal pore arrays are finally generated on the surface of those vesicles.
Visible Light‐Activated Ultralong‐Lived Triplet Excitons of Carbon Dots for White‐Light Manipulated Anti‐Counterfeiting
Authors: Xu Bin , Jia Yuehan , Ning Huiying , Teng Qian , Li Chenhao , Fang Xiaoqi , Li Jie , Zhou Heng , Meng Xiangeng , Gao Zhenhua , Wang Xue , Wang Zifei , Yuan Fanglong
Published: August 2023

Room temperature phosphorescence (RTP) has emerged as an interesting but rare phenomenon with multiple potential applications in anti‐counterfeiting, optoelectronic devices, and biosensing. Nevertheless, the pursuit of ultralong lifetimes of RTP under visible light excitation presents a significant challenge. Here, new phosphorescent materials that can be excited by visible light with record‐long lifetimes are demonstrated, realized through embedding nitrogen doped carbon dots (N‐CDs) into a poly(vinyl alcohol) (PVA) film. The RTP lifetime of the N‐CDs@PVA film is remarkably extended to 2.1 s excited by 420 nm, representing the highest recorded value for visible light‐excited phosphorescent materials. Theoretical and experimental studies reveal that the robust hydrogen bonding interactions can effectively reduce the non‐radiative decay rate and radiative transition rate of triplet excitons, thus dramatically prolong the phosphorescence lifetime. Notably, the RTP emission of N‐CDs@PVA film can also be activated by easily accessible low‐power white‐light‐emitting diode. More significantly, the practical applications of the N‐CDs@PVA film in state‐of‐the‐art anti‐counterfeiting security and optical information storage domains are further demonstrated. This research offers exciting opportunities for utilizing visible light‐activated ultralong‐lived RTP systems in a wide range of promising applications.
An Amiable Design of Cobalt Single Atoms as the Active Sites for Oxygen Evolution Reaction in Desalinated Seawater
Authors: Venkateswarlu Sada , Umer Muhammad , Son Younghu , Govindaraju Saravanan , Chellasamy Gayathri , Panda Atanu , Park Juseong , Umer Sohaib , Kim Jeonghyeon , Choi Sang‐Il , Yun Kyusik , Yoon Minyoung , Lee Geunsik , Kim Myung Jong
Published: August 2023

Green fuel from water splitting is hardcore for future generations, and the limited source of fresh water (<1%) is a bottleneck. Seawater cannot be used directly as a feedstock in current electrolyzer techniques. Until now single atom catalysts were reported by many synthetic strategies using notorious chemicals and harsh conditions. A cobalt single‐atom (CoSA) intruding cobalt oxide ultrasmall nanoparticle (Co3O4 USNP)‐intercalated porous carbon (PC) (CoSA‐Co3O4@PC) electrocatalyst was synthesized from the waste orange peel as a single feedstock (solvent/template). The extended X‐ray absorption fine structure spectroscopy (EXAFS) and theoretical fitting reveal a clear picture of the coordination environment of the CoSA sites (CoSA‐Co3O4 and CoSA‐N4 in PC). To impede the direct seawater corrosion and chlorine evolution the seawater has been desalinated (Dseawater) with minimal cost and the obtained PC is used as an adsorbent in this process. CoSA‐Co3O4@PC shows high oxygen evolution reaction (OER) activity in transitional metal impurity‐free (TMIF) 1 M KOH and alkaline Dseawater. CoSA‐Co3O4@PC exhibits mass activity that is 15 times higher than the commercial RuO2. Theoretical interpretations suggest that the optimized CoSA sites in Co3O4 USNPs reduce the energy barrier for alkaline water dissociation and simultaneously trigger an excellent OER followed by an adsorbate evolution mechanism (AEM).
RoboREIT: An interactive robotic tutor with instructive feedback component for requirements elicitation interview training
Authors: Görer Binnur , Aydemir Fatma Başak
Published: August 2023

Interviewing stakeholders is the most popular technique for eliciting requirements. The success of an interview depends on the interviewer's theoretical knowledge, preparedness, and communication skills. Practice interviews allow students to apply their knowledge and improve their skills through experience. This practical training is resource‐intensive, requiring the time and effort of a stakeholder for each student, which may not be feasible for a large number of students. This paper introduces RoboREIT, an interactive Robotic tutor for Requirements Elicitation Interview Training. RoboREIT addresses the scalability problem of practice sessions with a robotic tutor acting as a stakeholder during the interview and providing feedback after the interview. We performed an exploratory user study to evaluate RoboREIT and demonstrate its applicability in requirements elicitation interview training. The quantitative and qualitative analyses of the users' responses reveal the appreciation of RoboREIT. Our study is the first in the literature that utilizes a social robot in requirements elicitation interview education. RoboREIT's design incorporates replaying faulty interview stages and allows the student to learn from mistakes by a second time practicing. All participants praised the feedback component, which is not present in the state of the art, for being helpful in identifying the mistakes. A favorable response rate of 81% for the system's usefulness indicates the positive perception of the participants.
A lightweight adaptive random testing method for deep learning systems
Authors: Mao Chengying , Song Yue , Chen Jifu
Published: August 2023

In recent years, deep learning (DL) systems are increasingly used in the safety‐critical fields such as autonomous driving, medical diagnosis, and financial service. Although these systems have demonstrated an outstanding performance in enhancing the accuracy of decision‐making, they pose significant challenges to the trustworthiness due to their limited interpretability and inherent uncertainty. Adaptive random testing (ART) has been proved as an effective approach for ensuring the reliability of DL systems. However, existing ART methods for DL systems incur a heavy overhead in test case selection due to the computation of distances. To address this issue, we propose a lightweight adaptive random testing (Lw‐ARTDL) method for DL systems. In our improved algorithm, we employ the K‐Means technique to divide the entire test suite into several subsets. Then, for a candidate test case, we only calculate distances between it and the test cases within the category to which it belongs. This partition strategy ensures that the selected test cases are more representative while significantly reducing the computational cost. To validate the proposed algorithm, the comparison experiments between Lw‐ARTDL and the original ARTDL algorithm are conducted on two typical DL systems. The experimental results show that Lw‐ARTDL significantly reduces the overhead of failure detection, and exhibits stronger failure detection capability compared to ARTDL in most similarity metrics.
Effect of Residual Stress on the Continuous Cooling Transformation of High‐Strength Low‐Alloy Hot‐Rolled Strip
Authors: Fei Aigeng , Zhao Zhiyi , Xue Rundong
Published: August 2023

The external stress will change the transformation process and microstructure of the material, and the residual stress generated during the processing of the material will also affect the transformation. Herein, the effect of residual stress is simulated by applying uniaxial elastic loads during the continuous cooling of high‐strength low‐alloy hot‐rolled strip. The transformation process and microstructure of the samples under different stress conditions are investigated. The results show that residual stress can accelerate the transformation process, and the tensile stress is greater than the compressive stress. The degree of lattice mismatch in stressed samples is larger than that in unstressed samples, leading to dislocation proliferation. It is found that there is a phenomenon of residual stress‐induced grain growth according to the statistics of grain size of different samples. Due to the higher dislocation density and smaller curvature of the parent phase interface under compressive stress, the compressive stress samples have a higher nucleation rate, resulting in smaller grain size than the tensile stress samples. In addition, the transformation texture also changes under residual stress.
Conditional mixture modelling for heavy‐tailed and skewed data
Authors: Dong Aqi , Melnykov Volodymyr , Wang Yang , Zhu Xuwen
Published: August 2023

Overparameterization is a serious concern for multivariate mixture models as it can lead to model overfitting and, as a result, mixture order underestimation. Parsimonious modelling is one of the most effective remedies in this context. In Gaussian mixture models, the majority of parameters is associated with covariance matrices and parsimonious models based on factor analysers and spectral decomposition of dispersion parameters are the most popular in literature. Some drawbacks of these models include the lack of flexibility in imposing different covariance structures for individual components and limitations in modelling compact clusters. Recently introduced conditional mixture models provide substantial flexibility in addressing these concerns. The components of such mixtures are formulated as a product of conditional distributions with univariate Gaussian densities being the primary choice. However, the presence of heavy tails or skewness in any dimension can lead to fitting problems. We propose a flexible model that is free of the above‐mentioned limitations and name it a contaminated transformation conditional mixture model and demonstrate on a series of simulation studies that it can effectively account for skewness and heavy tails. Applications to real‐life data sets show good results and highlight the promise of the proposed model.
Recent Advances in the Development of Sustainable Composite Materials used as Membranes in Microbial Fuel Cells
Authors: James Anina , Velayudhaperumal Chellam Padmanaban
Published: August 2023

MFC can have dual functions; they can generate electricity from industrial and domestic effluents while purifying wastewater. Most MFC designs comprise a membrane which physically separates the cathode and anode compartments while keeping them electrically connected, playing a significant role in its efficiency. Popular commercial membranes such as Nafion, Hyflon and Zifron have excellent ionic conductivity, but have several drawbacks, mainly their prohibitive cost and non‐biodegradability, preventing the large‐scale application of MFC. Fabrication of composite materials that can function better at a much lower cost while also being environment‐friendly has been the endeavor of few researchers over the past years. The current review aims to apprise readers of the latest trends of the past decade in fabricating composite membranes (CM) for MFC. For emphasis on environmental‐friendly CM, the review begins with biopolymers, moving on to the carbon‐polymer, polymer‐polymer, and metal‐polymer CM. Lastly, critical analysis towards technology‐oriented propositions and realistic future directives in terms of strengths, weakness, opportunities, challenges (SWOC analysis) of the application of CM in MFC have been discussed for their possible large‐scale use. The focus of this review is the development of hybrid materials as membranes for fuel cells, while underscoring the need for environment‐friendly composites and processes.
Single‐cell combined with bulk‐RNA data reveal a pattern related to angiogenesis in breast cancer patients: Individualized medicine
Authors: Zhang Wei , Yu Yan , Yang Fan
Published: August 2023

Angiogenesis contributes to tumor progression, aggressive behavior, and metastasis. Although several endothelial dysfunction genes (angiogenesis‐related genes [ARGs]) have been identified as diagnostic biomarkers of breast cancer in a few studies, the mixed effects of ARGs have not been thoroughly investigated. The RNA sequencing data and patient survival datasets of breast cancer were obtained for further analysis. MSigDB website includes angiogenesis‐related mechanisms. The consensus clustering analysis identifies 1082 breast cancer patients as three clusters. differential expression genes (DEGs) were identified by limma package. GO combined with gene set enrichment analysis (GSEA) to identify cytogenetic functions between two predefined clusters. Then Serpin Family F Member 1 (SERPINF1), angiomotin (AMOT), promyelocytic leukemia (PML), and BTG anti‐proliferation factor 1 (BTG) were selected to construct prediction models using random forest survival analysis. External validation was performed using the GSE58812 triple‐negative breast cancer cohort as the validation set. The median scoring system was used to discern the high‐ and low‐risk groups, and there was a significant difference in their diagnostic results. Immunological infiltration scores were calculated using single sample gene set enrichment analysis (ssGSEA) and xCell algorithms, and consciousness scores were calculated using the R package “oncoPredict” for drugs in the Genomics of Drug Sensitivity in Cancer (GDSC) database. In addition, the single‐cell analysis of seven triple‐negative breast cancers using scRNA‐seq information from GSE118389 demonstrated the interpretation of SERPINF1, AMOT, PML, and BTG1. In conclusion, this investigation engineered ARG‐centric disease paradigms that not only prognosticated prospective therapeutic compounds, but also projected their mechanistic trajectories, thereby facilitating the proposition of tailored treatments within diverse patient cohorts diagnosed with breast cancer.
Re: Correspondence on ‘Fetal myocardial deformation measured with two‐dimensional speckle‐tracking echocardiography: longitudinal prospective cohort study of 124 healthy fetuses’
Authors: DeVore G. R.
Published: August 2023

Linked article: This Correspondence comments on van Oostrum et al. Click here to view the article.
Seasonality and evaporation of water resources in Reynolds Creek Experimental Watershed and Critical Zone Observatory, Southwestern Idaho, USA
Authors: Schlegel Melissa E. , Souza Jennifer , Warix Sara R. , MacNeille Ruth , Murray Erin , Radke Anna , Godsey Sarah E. , Seyfried Mark S. , Finney Bruce , Flerchinger Gerald , Lohse Kathleen A.
Published: August 2023

The Reynolds Creek Experimental Watershed (RCEW) and Critical Zone Observatory (CZO), located south of the western Snake River Plain in the Intermountain West of the United States, is the site of over 60 years of research aimed at understanding integrated earth processes in a semi‐arid climate to aid sustainable use of environmental resources. Meteoric water lines (MWLs) are used to interpret hydrologic processes, though equilibrium and nonequilibrium processes affect the linear function and can reveal seasonal and climatological effects, necessitating the development of local meteoric water lines (LMWLs). At RCEW‐CZO, an RCEW LMWL was developed using non‐volume‐weighted, orthogonal regression with assumed error in both predictor and response variables from several years of precipitation (2015, 2017, 2019, 2020, and 2021) primarily at three different elevations (1203, 1585, and 2043 m). As most precipitation is evaporated or intercepted by vegetation in the driest months, an RCEW LMWL for groundwater recharge (RCEW LMWL‐GWR) was also developed using precipitation from the wettest months (November through April). The RCEW LMWL (δ2H = 7.41 × δ18O – 3.09) is different from the RCEW LMWL‐GWR (δ2H = 8.21 × δ18O + 9.95) and compares favorably to other LMWLs developed for the region and climate. Comparative surface, spring, and subsurface water datasets within the RCEW‐CZO are more similar to precipitation during the wettest months than dry months, illustrating that some semi‐arid hydrologic systems may most appropriately be compared to MWLs developed from precipitation only from the wettest season.
Performance of variable characteristics on MHD Jeffery nanofluid over spinning disk with Cattaneo‐Christov heat flux and microswimmers
Authors: Khan Noor Saeed , Alshammari Basmah H. , Noor Adeeb , Hassine Siwar Ben Hadj
Published: August 2023

Variable properties like thermal conductivity and variable thickness of the disk are analyzed for the Jeffery nanofluid and gyrotactic microorganisms in rotating system taking into account the Cattaneo‐Christov heat flux, velocity slip and thermal radiation effects. Zero mass flux is assumed at the disk surface for the better and high accuracy of the out‐turn. The governing equations of the problem are transformed into nonlinear ordinary differential equations by introducing the appropriate similarity transformations which are solved analytically by the homotopy analysis method. The effects of all the parameters are given in detail through the graphs.
Constraining Vector Dark Matter with neutrino experiments
Authors: Brzeminski Dawid , Das Saurav , Hook Anson , Ristow Clayton
Published: August 2023

Abstract

Vector Dark Matter (VDM) that couples to lepton flavor (Le, Lμ, Lτ) acts similarly to a chemical potential for the neutrino flavor eigenstates and modifies neutrino oscillations. VDM imparts unique signatures such as time and directional dependence with longer baselines giving better sensitivity. We use the non-observation of such a signal at Super-Kamiokande to rule out the existence of VDM in a region of parameter space several orders of magnitude beyond other constraints and show the projected reach of future experiments such as DUNE.
’t Hooft loops and integrability
Authors: Kristjansen Charlotte , Zarembo Konstantin
Published: August 2023

Abstract

We consider the defect CFT defined by a ’t Hooft line embedded in $$ \mathcal{N} $$
N
= 4 super Yang-Mills theory. By explicitly quantizing around the given background we exactly reproduce a prediction from S-duality for the correlators between the ’t Hooft line and chiral primaries in the bulk and pave the way for higher loop analyses for non-protected operators. Furthermore, we demonstrate at the leading perturbative order that correlators between the ’t Hooft line and non-protected bulk operators can be efficiently computed using integrability. As a byproduct we find new integrable overlaps in $$ \mathfrak{sl} $$
sl
(2) spin chains in different representations.
A Rutherford-like formula for scattering off Kerr-Newman BHs and subleading corrections
Authors: Bianchi Massimo , Gambino Claudio , Riccioni Fabio
Published: August 2023

Abstract

By exploiting the Kerr-Schild gauge, we study the scattering of a massive (charged) scalar off a Kerr-Newman black hole. In this gauge, the interactions between the probe and the target involve only tri-linear vertices. We manage to write down the tree-level scattering amplitudes in analytic form, from which we can construct an expression for the eikonal phase which is exact in the spin of the black hole at arbitrary order in the Post-Minkowskian expansion. We compute the classical contribution to the cross-section and deflection angle at leading order for a Kerr black hole for arbitrary orientation of the spin. Finally, we test our method by reproducing the classical amplitude for a Schwarzschild black hole at second Post-Minkowskian order and outline how to extend the analysis to the Kerr-Newman case.
Explaining large electromagnetic logarithms from loops of inflationary gravitons
Authors: Glavan D. , Miao S. P. , Prokopec T. , Woodard R.P.
Published: August 2023

Abstract

Recent progress on nonlinear sigma models on de Sitter background has permitted the resummation of large inflationary logarithms by combining a variant of Starobinsky’s stochastic formalism with a variant of the renormalization group. We reconsider single graviton loop corrections to the photon wave function, and to the Coulomb potential, in light of these developments. Neither of the two 1-loop results have a stochastic explanation, however, the flow of a curvature-dependent field strength renormalization explains their factors of ln(a). We speculate that the factor of ln(Hr) in the Coulomb potential should not be considered as a leading logarithm effect.
Primordial black hole archaeology with gravitational waves from cosmic strings
Authors: Ghoshal Anish , Gouttenoire Yann , Heurtier Lucien , Simakachorn Peera
Published: August 2023

Abstract

Light primordial black holes (PBHs) with masses smaller than 109 g (10−24M⊙) evaporate before the onset of Big-Bang nucleosynthesis, rendering their detection rather challenging. If efficiently produced, they may have dominated the universe energy density. We study how such an early matter-dominated era can be probed successfully using gravitational waves (GW) emitted by local and global cosmic strings. While previous studies showed that a matter era generates a single-step suppression of the GW spectrum, we instead find a double-step suppression for local-string GW whose spectral shape provides information on the duration of the matter era. The presence of the two steps in the GW spectrum originates from GW being produced through two events separated in time: loop formation and loop decay, taking place either before or after the matter era. The second step — called the knee — is a novel feature which is universal to any early matter-dominated era and is not only specific to PBHs. Detecting GWs from cosmic strings with LISA, ET, or BBO would set constraints on PBHs with masses between 106 and 109 g for local strings with tension Gμ = 10−11, and PBHs masses between 104 and 109 g for global strings with symmetry-breaking scale η = 1015 GeV. Effects from the spin of PBHs are discussed.
Multipoint correlators on the supersymmetric Wilson line defect CFT. Part II. Unprotected operators
Authors: Barrat Julien , Liendo Pedro , Peveri Giulia
Published: August 2023

Abstract

We continue our study of multipoint correlators of scalar fields on the 1d defect CFT generated by inserting operators along the Maldacena-Wilson line in $$ \mathcal{N} $$
N
= 4 SYM. We present a weak-coupling recursion relation that captures correlators at next-to-leading order involving an arbitrary number of the elementary scalar fields ϕi and ϕ6, the latter being unprotected. We can then build correlators of composite operators by pinching the scalar fields together. As a demonstration of our method, we give explicit results for correlators containing up to six points. We also expand some selected correlators using recently obtained conformal blocks in the comb and snowflake channel, and check that the extracted low-lying CFT data is consistent with explicit computations.
Towards AdS distances in string theory
Authors: Li Yixuan , Palti Eran , Petri Nicolò
Published: August 2023

Abstract

The AdS Distance Conjecture proposes to assign a notion of distance between AdS vacua in quantum gravity. We perform some initial developments of this idea. We first propose more sharply how to define a metric on conformal variations of AdS through the action. This metric is negative, making the distance ill-defined, a property relating to the famous conformal factor problem of quantum gravity. However, in string theory, variations of the AdS conformal factor are accompanied by variations of the internal dimensions and of the background flux. We propose an action metric, which accounts for all of these variations simultaneously. Accounting for the variations of the overall volume of the internal dimensions can flip the sign of the action metric making it positive. This positivity is related to the absence of scale separation between the internal and external dimensions: the negative external conformal contribution must be sub-dominant to the positive internal contribution. We then focus specifically on the families of solutions of eleven-dimensional supergravity on AdS4 × S7 and AdS7 × S4. For these, there is only a single further additional contribution to the action metric coming from variations of the Freund-Rubin flux. This contribution is subtle to implement, and the unique prescription we find requires singling out the radial direction of AdS as special. Adding the flux contribution yields an overall total action metric which becomes positive for both the AdS4 and AdS7 families of solutions. The final result is therefore a procedure which yields a well-defined distance for these families of solutions.
Development and internal validation of a clinical prediction model for serious complications after emergency laparotomy
Authors: Kokkinakis Stamatios , Kritsotakis Evangelos I. , Paterakis Konstantinos , Karali Garyfallia-Apostolia , Malikides Vironas , Kyprianou Anna , Papalexandraki Melina , Anastasiadis Charalampos S. , Zoras Odysseas , Drakos Nikolas , Kehagias Ioannis , Kehagias Dimitrios , Gouvas Nikolaos , Kokkinos Georgios , Pozotou Ioanna , Papatheodorou Panayiotis , Frantzeskou Kyriakos , Schizas Dimitrios , Syllaios Athanasios , Palios Ifaistion M. , Nastos Konstantinos , Perdikaris Markos , Michalopoulos Nikolaos V. , Margaris Ioannis , Lolis Evangelos , Dimopoulou Georgia , Panagiotou Dimitrios , Nikolaou Vasiliki , Glantzounis Georgios K. , Pappas-Gogos George , Tepelenis Kostas , Zacharioudakis Georgios , Tsaramanidis Savvas , Patsarikas Ioannis , Stylianidis Georgios , Giannos Georgios , Karanikas Michail , Kofina Konstantinia , Markou Markos , Chrysos Emmanuel , Lasithiotakis Konstantinos
Published: August 2023

Purpose

Emergency laparotomy (EL) is a common operation with high risk for postoperative complications, thereby requiring accurate risk stratification to manage vulnerable patients optimally. We developed and internally validated a predictive model of serious complications after EL.

Methods

Data for eleven carefully selected candidate predictors of 30-day postoperative complications (Clavien-Dindo grade >  = 3) were extracted from the HELAS cohort of EL patients in 11 centres in Greece and Cyprus. Logistic regression with Least Absolute Shrinkage and Selection Operator (LASSO) was applied for model development. Discrimination and calibration measures were estimated and clinical utility was explored with decision curve analysis (DCA). Reproducibility and heterogeneity were examined with Bootstrap-based internal validation and Internal–External Cross-Validation. The American College of Surgeons National Surgical Quality Improvement Program’s (ACS-NSQIP) model was applied to the same cohort to establish a benchmark for the new model.

Results

From data on 633 eligible patients (175 complication events), the SErious complications After Laparotomy (SEAL) model was developed with 6 predictors (preoperative albumin, blood urea nitrogen, American Society of Anaesthesiology score, sepsis or septic shock, dependent functional status, and ascites). SEAL had good discriminative ability (optimism-corrected c-statistic: 0.80, 95% confidence interval [CI] 0.79–0.81), calibration (optimism-corrected calibration slope: 1.01, 95% CI 0.99–1.03) and overall fit (scaled Brier score: 25.1%, 95% CI 24.1–26.1%). SEAL compared favourably with ACS-NSQIP in all metrics, including DCA across multiple risk thresholds.

Conclusion

SEAL is a simple and promising model for individualized risk predictions of serious complications after EL. Future external validations should appraise SEAL’s transportability across diverse settings.
Prenatal Diagnosis Rate of Critical Congenital Heart Disease Remains Inadequate with Significant Racial/Ethnic and Socioeconomic Disparities and Technical Barriers
Authors: Davtyan Arpine , Ostler Heidi , Golding Ian Fraser , Sun Heather Y.
Published: August 2023

Prenatal diagnosis (preDx) of critical congenital heart disease (CCHD) decreases neonatal morbidity and mortality. Obstetrical fetal cardiac imaging guidelines in 2013 aimed to increase preDx. The objectives of this study were to determine the contemporary preDx rate of CCHD and identify maternal–fetal factors and variations in prenatal care that may be potential barriers. This retrospective single center study evaluated maternal demographics and characteristics of infants with CCHD (requiring cardiac catheterization or surgical intervention before 6 months-old) between 2016 and 2019. 58% of the 339 infants with CCHD had preDx. Infants with preDx were more likely to have mothers ≥ 35 years-old (p = 0.028), family history of CHD (p = 0.017), health insurance (p = 0.002), or anatomic scan with perinatology (p < 0.001). Hispanic infants were less likely to have preDx (45.6%, p = 0.005). PreDx rates were higher in infants with extracardiac/genetic anomalies (p < 0.001) and significantly different between CCHD subtypes (76% for single ventricle, 51% for biventricular/four-chamber view, 59% for proximal outflow tract anomalies, and 48% for distal great artery anomalies; p = 0.024). In infants without preDx, 25% of their mothers had indication for, but did not undergo, fetal echocardiography. PreDx rates of CCHD remains inadequate across subtypes detectable by standard fetal cardiac screening views, particularly in uninsured and Hispanic communities.
High prevalence of past hepatitis B virus infection in diffuse large B cell lymphoma: a retrospective study from Italy
Authors: Visentini Marcella , Pica Andrea , D’Ippolito Giancarlo , Sculco Eleonora , La Gualana Francesca , Gragnani Laura , Miglionico Marzia , Mazzaro Cesare , Fiorilli Massimo , Basili Stefania , Martelli Maurizio , Di Rocco Alice , Casato Milvia , Gentile Giuseppe , Pulsoni Alessandro
Published: August 2023

Studies from high endemic areas, mostly China, indicate that surface antigen positive (HBsAgpos) chronic hepatitis B virus (HBV) infection is associated with an increased risk of developing diffuse large B-cell lymphoma (DLBCL), whereas studies in low endemic areas have provided conflicting results. Past infection, serologically defined by negative HBsAg and positive anti-core antibody (HBsAgnegHBcAbpos), has also been suggested to increase the risk of B-cell non-Hodgkin’s lymphoma (NHL) in high endemic areas. We retrospectively reviewed unselected clinical records of 253 patients with DLBCL (54% male, aged 60.3 ± 14.6 years at diagnosis) and 694 patients with different types of indolent B-cell NHL (46% male, aged 61.7 ± 12.8 years). Patients were seen at a single center in Italy between 2001 and 2022 and HBV serological status (HBsAg, HBsAb, HBcAb, HBeAg, HBeAb, and HBV DNA) was analyzed through enzyme-linked immunosorbent assays and molecular assays; patients infected with hepatitis C virus or human immunodeficiency virus were excluded. We used an unconditional multiple logistic regression model including as matching variables gender, age at diagnosis, immigrant status, and HBV serological status. Patients with DLBCL had, compared to indolent NHL, a higher prevalence of HBsAgpos active infection (odds ratio (OR) 2.8, 95% confidence interval (95% CI) 1.2–6.3, p = 0.014). Strikingly, patients with DLBCL had also a significantly higher prevalence of past infection (OR 2.4, 95% CI 1.5–4.0, p = 0.0006). Male gender was associated with increased risk of DLBCL independently of the HBV serological status. These findings suggest that both past and active HBV infection may increase the risk of DLBCL in a low endemic area. Our study needs confirmation by studies in areas or populations with different rates of chronic or past HBV infection.
The validity of ultrasound and shear wave elastography to assess the quality of the rotator cuff
Authors: Peeters Nina H. C. , van der Kraats Annick M. , van der Krieken Thomas E. , van Iersel Dave , Janssen Esther R. C. , Heerspink Frederik O. Lambers
Published: August 2023

Objectives

US with shear wave elastography (SWE) could reduce the burden and costs of the diagnostic process for patients with rotator cuff disorders. The aim of this study is to investigate the validity of US and SWE in preoperative assessment of fatty infiltration (FI) and muscle atrophy of the supraspinatus (SSP) and infraspinatus (ISP) muscles.

Methods

Patients with a rotator cuff disorder and a recent shoulder CT or MRI scan were eligible to participate. Goutallier and Warner stages of the SSP and ISP muscle were measured on the scan, for assessment of FI and muscle atrophy, respectively. These findings were compared with shear wave velocities (SWVs) assessed on US. Visual assessment of FI on US was compared with the Goutallier stage. To quantify the amount of muscle atrophy, the occupation ratio between SSP fossa and muscle was measured on MRI and US.

Results

Seventy-eight shoulders were included in the analysis. The correlation found between the occupation ratio on US and Warner and Goutallier stage and ratio on MRI ranged between r =  − 0.550 to 0.589. The Goutallier stage of ISP and SSP muscle assessed on US showed a fair correlation with the Goutallier stage on a scan of r = 0.574 and r = 0.582, respectively. There was a poor correlation between the SWVs and scan results (r =  − 0.116 to 0.07).

Conclusion

SWE is not a valid method to measure the amount of FI or muscle atrophy in the SSP muscle. Therefore, SWE is not a suitable alternative for MRI in standard preoperative diagnostics in rotator cuff pathologies.

Clinical relevance statement

Shear wave elastography should not be used in the diagnostics of rotator cuff pathologies.

Key Points

• There is a fair correlation between the Goutallier stage of the supraspinatus and infraspinatus muscle assessed on MRI and CT and visual assessment of fatty infiltration achieved on US.

• Shear wave elastography is not a valid tool for the determination of the amount of fatty infiltration or muscle atrophy.

• Shear wave elastography should not be used as a cheaper and less burdensome alternative for diagnostics in rotator cuff pathologies.
Determination of the absorption function of laser-heated soot particles from spectrally resolved laser-induced incandescence signals using multiple excitation wavelengths
Authors: Lang Peter , Braeuer Phillipp A. B. , Müller Marcel N. , Faderl Sebastian R. , Huber Franz J. T. , Bauer Florian J. , Will Stefan
Published: August 2023

In this work, the optical properties of soot particles from a Gülder burner fueled with both ethylene or propane gas were investigated in situ using laser-induced incandescence. The particles in the flame were irradiated with four different laser wavelengths, namely 450 nm, 532 nm, 600 nm and 650 nm. The resulting laser-induced emissions were detected spectrally and temporally resolved by means of a spectrograph and an intensified camera at different delay times with respect to the laser pulse. To determine the optical properties of the particles from the data, the emitted spectra were simulated using a spectroscopic model with variable input parameters, and a regression was performed against the measured data. On the basis of an functional approach of the absorption function on wavelength, the dispersion exponent for soot was evaluated for a reference position on the centre axis at 40 mm height above the burner. It was found that the different fuel gases lead to similar values with regard to the absorption function, which can be expressed by a mean dispersion exponent with a value of 1.75 for ethylene and 1.68 for propane.
Endoscopic trans-sphenoidal pituitary surgery does not impact postoperative nasal quality of life
Authors: Weiland Thomas , Gellner Verena , Pondorfer Prisca , Hortobagyi David , Maitz Emanuel , Kiss Peter , Borenich Andrea , Reininghaus Eva Z. , Thurnher Dietmar , Tomazic Peter Valentin
Published: August 2023

Purpose

The aim of this prospective longitudinal study was to assess both subjective quality of life using questionnaires and objective examination of nasal function with regard to olfaction, nasal air flow and mucociliary clearance in patients after minimally invasive, turbinate-preserving endoscopic transnasal trans-sphenoidal pituitary surgery.

Methods

Patients undergoing endoscopic transnasal pituitary surgery were recruited prospectively and examined during three study visits, preoperatively and 3 and 6 months postoperatively. We examined nasal function using sniffin' sticks test, rhinomanometry, saccharin transit time test, and endoscopic and radiological scores. In addition, the influence on subjective quality of life and mental health was recorded using the Sinonasal-Outcome-Test-20 (SNOT-20) and the Hospital-Anxiety-and-Depression-Scale (HADS).

Results

20 patients undergoing endoscopic pituitary tumor resections were included. No significant changes in olfaction or mucociliary clearance were noted. Nasal air flow showed a tendency to increase in the postoperative course lacking significance. Both the endoscopy and the radiological scores showed a significant deterioration, especially after 3 months, with a trend towards improvement over time. However, neither the SNOT-20 nor the HADS showed significant changes compared to baseline.

Conclusions

Our concept of minimally invasive endoscopic tumor resections on the pituitary gland with preservation of nasal turbinates shows low morbidity for the patient. Despite objectifiable surgery-associated changes in the nose, nasal physiology in terms of smell, airflow and mucociliary clearance can be preserved and the subjective quality of life of our patients remains stable.