bluuebunny/crossref_metadata_2025 huggingface dataset:
Halogen Impact on the Supramolecular Organization of Chiral Phthalimide Emitters Displaying Room Temperature Phosphorescence
Authors: Demangeat Catherine , Remond Maxime , Roisnel Thierry , Quinton Cassandre , Favereau Ludovic
Published: July 2024

Room temperature phosphorescence from organic materials has attracted an increasing attention in the recent years due to their potential application in various advancing technologies, notably in bioimaging and displays. In this context, heavy atoms such as halogen ones revealed useful tools to enhance the spin‐orbit coupling (SOC) of molecular organic phosphors. However, the effect of halogen at the supramolecular level remains less understood, especially in the field of molecular crystals where additional factors can impact the phosphorescence emission. Here, we investigate external effect of halogens on the phosphorescence of chiral phthalimides molecular crystals. The results show that changing the nature of the halogen atom onto the phthalimide core leads to an evolution of the photophysical properties of the materials which does not necessarily follow the classical trend imposed by the expected internal heavy atom effect. Beyond this aspect, we showed that the halogen atom has a profound impact on the packing between the chromophores at the supramolecular level which is of paramount importance towards the optical properties (PLQY and lifetimes) of the different phosphors examined.
Robust and Irreversible Sortase‐Mediated Ligation by Empolyment of Sarkosyl
Authors: Xiao Yihang , Wu Mingxuan
Published: July 2024

Sortase‐mediated ligation (SML) is a widely used method for peptide and protein ligation due to ease of substrate preparation and fast enzymatic kinetics. But there are drawbacks that limit broader applications. Sorting motif in substrates may not be exposed to sortase efficiently due to folding or aggregation. In addition, the ligation is reversible under transpeptidation equilibrium that restricts ligation yield. Here we report a simple but robust method to overcome such limitations. By employment of sarkosyl, the detergent alters substrate conformation to raise sorting motif accessibility for sortase catalysis. Moreover, transpeptidation becomes irreversible presumably by formation of micelle to shield ligation products from sortase. In consequence, excellent yields were achieved from sortase variants with different substrate specificity. Notably, this method is compatible with peptides or proteins capable of forming liquid‐liquid phase separation (LLPS), presenting a powerful approach for the conjugation of aggregation‐prone substrates. Therefore, we believe the sarkosyl‐enhanced SML could be widely applied in peptide and protein chemistry and the unique irreversible transpeptidation mechanism offers an insight to detergent‐driven equilibrium.
Bridging Titanium Nitrido Complexes Containing A Linear Ti−N−Ti Core with A Two‐Coordinate Nitrido Ligand
Authors: Okumura Akira , Ghana Priyabrata , Spaniol Thomas P. , Okuda Jun
Published: July 2024

A series of titanium μ2‐nitrido complexes supported by the triamidoamine ligand Xy‐N3N (Xy‐N3N={(3,5‐Me2C6H3)NCH2CH2}3N3−) is reported. The titanium azido complex [(Xy‐N3N)TiN3] (1‐N3), prepared by salt metathesis of the chloride complex [(Xy‐N3N)TiCl] (1‐Cl) with NaN3, reacted with lithium metal or with alkali metal naphthalenides (alkali metal M=Na, K, and Rb) in THF to give the corresponding dinuclear μ2‐nitrido complexes M[(Xy‐N3N)Ti=N‐Ti(Xy‐N3N)] (2‐M; M=Li, Na, K, Rb). Single crystal X‐ray diffraction studies of 2‐Li, 2‐Na, and 2‐K revealed alkali metal dependent structures in the solid state. While 2‐Li and 2‐K contain a μ2‐nitrido ligand with a linear Ti−N−Ti core, 2‐Na includes a μ3‐nitrido ligand as part of a T‐shape Ti2NaN fragment with the sodium cation weekly coordinated to the nitrido nitrogen atom. When the synthesis of the nitrido complexes was carried out in the presence of excess alkali metals, decomposition of the nitrido complexes was observed affording some intractable titanium species along with the trialkali metal salts [M3(Xy‐N3N)] (3‐M) (M=Li, Na, K, and Rb). These salts were also prepared by deprotonation of (Xy‐N3N)H3 with the corresponding alkali metal hexamethyldisilazide and characterized by multinuclear NMR spectroscopy as well as single crystal X‐ray diffraction.
Structure‐Function Relationship of Iron Oxide Nanoflowers: Optimal Sizes for Magnetic Hyperthermia Depending on Alternating Magnetic Field Conditions
Authors: Bejko Megi , Yaman Yasmina Al , Keyes Anthony , Bagur Auriane , Rosa Patrick , Gayot Marion , Weill Francois , Mornet Stéphane , Sandre Olivier
Published: July 2024

Iron oxide nanoflowers (IONFs) that display singular magnetic properties can be synthesized through a polyol route first introduced almost 2 decades ago by Caruntu et al., presenting a multi‐core morphology in which several grains (around 10 nm) are attached together and sintered. These outstanding properties are of great interest for magnetic field hyperthermia, which is considered as a promising therapy against cancer. Although of significantly smaller diameter, the specific adsorption rate (SAR) of IONFs reach values on the order of 1 kW g−1, as large as “magnetosomes” that are natural magnetic nanoparticles typically ~40 nm found in certain bacteria, which can be grown artificially but with much lower yield compared to chemical synthesis such as the polyol route. This work aims at better understanding the structure‐property relationships, linking the internal IONF nanostructure as observed by high resolution transmission electron microscopy (HR‐TEM) to their magnetic properties. A library of mono‐ and multicore IONFs is presented, with diameters ranging from 11 to 30 nm in a narrow size distribution. More particularly, by relating their structural features (diameter, morphology, defects…) to their magnetic properties investigated by utilizing AC magnetometry over a wide range of alternating magnetic field (AMF) conditions, we showed that the SAR values of all synthesized batches vary with overall diameter and number of constituting cores. These variations are in qualitative agreement with theoretical predictions either by the Linear Response Theory (LRT) at low fields or with the Stoner‐Wohlfarth (SW) model at larger amplitudes, and with numerical simulations reported previously. More precisely, our results show a continuous (almost quadratic) increase of SAR with IONF diameter for AMF amplitudes of 20 kA m−1 and above, whatever the frequency between 146 and 344 kHz, and a pronounced maximum at an IONF diameter of 22 nm for amplitudes of 16 kA m−1 and below. Thank to this understanding of the impact of size and core multiplicity, stable colloidal solutions of IONPs can be synthesized with diameters targeting a SAR value adapted to the theragnostic approach envisioned.
Nitrile‐Stabilized Quaternary Ammonium Ylide as an Arylcyanomethylene Transfer Agent: Diastereoselective Synthesis of Spiro‐Cyanocyclopropyl‐2‐Oxindoles
Authors: Nagpure Mithilesh , Guchhait Sankar K.
Published: July 2024

Nitrile‐stabilized quaternary ammonium ylide as an effective aryl‐cyanomethylene transfer agent has been explored for the first time, which enables a spirocyclopropanation process with conjugated carboxamide of indole heterocycle. The developed In(OTf)3‐catalyzed method provides a straightforward, diastereoselective access to pharmaceutically relevant spiro‐cyclopropane‐2‐oxindole skeleton assembled with an α‐cyano and two (hetero)aromatic substitutions. The common difficulties of a cyclopropanation process, e. g., a conjugated carboxamide as valid substrate, cleavage‐susceptibility of amide bond, substrates scope limited to preferentially electron‐withdrawing group containing molecules, and the competing dehydrocyanation reaction of product generated from nitrile‐stabilized ylide have been overcome in the present spirocyclopropanation process.
Language barriers in head and neck cancer: Matched pair analysis of outcomes between non‐English speaking and English‐speaking patients
Authors: Chen Allen M.
Published: July 2024

Purpose

As society grows in cultural diversity, an increasing proportion of patients are expected to be from non‐English speaking backgrounds. This study sought to compare the clinical outcomes between non‐English speakers and English speakers treated by radiation therapy for head and neck cancer.

Methods and materials

Seventy‐five non‐English speaking patients with squamous cell carcinoma of the head and neck were matched to English‐speaking controls based on patient and disease variables; clinical outcomes were compared.

Results

Non‐English speaking patients had inferior 3‐year overall survival (64% vs. 77%, p = 0.02) and progression‐free survival (59% vs. 73%, p = 0.01) compared with the English‐speaking cohort. On logistical regression, non‐English‐speaking status was associated with a significantly increased risk of overall death (OR = 1.41; 95% CI, 1.09–1.92).

Conclusions

Prognosis differed significantly between non‐English speaking and English‐speaking patients. Culturally tailored programs to address language barriers should be considered to ameliorate disparities in outcome.
Special educational needs provision and academic outcomes for children with teacher reported language difficulties at school entry
Authors: Griffiths Sarah , Lucas Laura , Gooch Debbie , Norbury Courtenay Frazier
Published: July 2024

Background

Language ability predicts academic attainment across the curriculum. Teacher report of language difficulties may therefore help schools identify children that require Special Educational Needs (SEN) provision. Special Educational Needs provision is intended to enable children to reach their academic potential, however the effectiveness of this for children with language difficulties is unknown.

Methods

We linked teacher‐ratings on a brief language difficulties questionnaire (13‐item) collected in the first year of primary school (N = 7013), with data on SEN provision until age 12–13 and scores on statutory assessments at ages 5–6, 6–7 and 10–11 years from the National Pupil Database (UK). We conducted a preregistered analysis to (a) test the association between teacher‐reported language difficulties and later academic outcomes, (b) identify predictors of subsequent SEN provision for monolingual children with language difficulties and (c) test whether SEN provision is associated with better academic outcomes for these children.

Results

Teacher‐reported language difficulties predicted achievement in phonics (rs > 0.41), reading (rs > 0.38), writing (rs > 0.32) and maths (rs > 0.40) assessments up to 7 years later. For those with language difficulties, having an existing diagnosis of a neurodevelopmental condition or sensory impairment was the strongest predictor of SEN registration (OR [95% CI] 8.33 [4.12, 19.24]) and special education placement (OR [95% CI] 18.89 [9.29, 42.01]) during primary school. However, 38% of children registered as having a primary speech, language and communication need, lost this registration during transition to secondary education. We could not estimate the effect of SEN provision on academic outcomes, as the majority of children with high propensity to receive SEN provision did receive provision, and very few children in SEN settings completed statutory assessments.

Conclusions

Teacher perceptions of language difficulties at school entry, in the presence of additional risk factors, should prompt SEN provision. Recognition and support for language difficulties should be sustained throughout children's education.
Resolving abrupt frontal gradients in zooplankton community composition and marine snow fields with an autonomous Zooglider
Authors: Gastauer Sven , Ohman Mark D.
Published: July 2024

An autonomous Zooglider navigated across the California Current Front into low salinity, minty waters characteristic of the California Current proper in both summers of 2019 and 2021. Diving to 400 m depth, Zooglider transited another near‐surface frontal gradient somewhat inshore. These frontal gradients were generally associated with changes in intensity, size composition, and Diel Vertical Migration responses of acoustic backscatterers. They were also associated with pronounced changes in zooplankton community composition, as assessed by a shadowgraph imaging Zoocam. Zoocam detected a decline in concentrations of copepods, appendicularians, and marine snow in the offshore direction, and an overall shift in community structure to a higher proportion of carnivorous taxa (and, in 2019, of planktonic rhizaria). No taxon was consistently elevated at all the peak frontal gradients, but appendicularians, copepods, and rhizarians sometimes showed front‐related increases in concentration. Such frontal gradient regions represent relatively abrupt transitions to different communities of planktonic organisms and suspended marine snow particles, with consequences for predator–prey relationships and the dominant vectors of particle export into subsurface waters.
High‐frequency stability estimates for the linearized inverse boundary value problem for the biharmonic operator with attenuation on some bounded domains
Authors: Choudhury Anupam Pal , Kumar T. Ajith
Published: July 2024

In this article, high‐frequency stability estimates are explored for the determination of the zeroth‐order perturbation of the biharmonic operator with constant attenuation from the linearized partial Dirichlet‐to‐Neumann map when part of the boundary is inaccessible and flat. The results obtained suggest improvement of the stability with an appropriate choice of frequency.
Radiomic feature robustness in CT scans affected by fiducial marker induced streak artifacts for patients with hepatocellular carcinoma
Authors: Verstappen Damon , Pasquier David , Chen Yi , Lambin Phillipe , Woodruff Henry C.
Published: July 2024

Background

Stereotactic body radiation therapy for hepatocellular carcinoma necessitates the implantation of gold fiducial markers in the liver, resulting in artifacts on computed tomography (CT) scans, which affect radiomic feature values.

Purpose

This report aims to assess the effect of these artifacts on radiomic features and how removing CT slices affects radiomic features extracted from 3D regions of interest (ROI).

Methods

First, the range variation in 38 tumor contours unaffected by artifacts was assessed after sequentially and randomly removing 25%, 50%, 75% of slices. Subsequently, the agreement of feature values before and after removing ROI slices containing artifacts from 186 patients’ CT scans was assessed with Lin's concordance correlation coefficient (CCC) and a Wilcoxon signed‐rank test.

Results

In artifact‐free tumor volumes, at least 71% of features remain robust with up to 50% of slices removed, while 56% remains robust with up to 75% of slices removed. When comparing contours before and after removing slices containing artifacts, around a third of features in the tumor contour and surrounding area remain robust (CCC > 0.9), compared to 44% in the healthy liver. Concerning the tumor, 13% (Gray Level Size Zone Matrix) to 61% (first order) of the features remain robust (CCC > 0.9). Over 90% of features differ significantly as assessed by Wilcoxon signed‐rank test, however.

Conclusions

This study demonstrates that removing slices containing artifacts is a feasible solution for the CT fiducial problem in this patient population and provides insight into which features are affected.
A feasibility study of dosimetry for breast cancer radiotherapy based on body surface changes
Authors: Deng Yongjin , Qiu Minmin , Zhong Jiajian , Xiao Zhenhua , Bao Yong , Huang Botian
Published: July 2024

Background

The requirement for precise and effective delivery of the actual dose to the patient grows along with the complexity of breast cancer radiotherapy. Dosimetry during treatment has become a crucial component of guaranteeing the efficacy and security.

Purpose

To propose a dosimetry method during breast cancer radiotherapy based on body surface changes.

Methods

A total of 29 left breast cancer radiotherapy cases were retroactively retrieved from an earlier database for analysis. Non‐rigid image registration and dose recalculation of the planning computed tomography (CT) referring to the Cone‐beam computed tomography were performed to obtain dose changes. The study used 3D point cloud feature extraction to characterize body surface changes. Based on the correlation proof, a mapping model is developed between body surface changes and dose changes using neural network framework. The MSE metrics, the Euclidean distances of feature points and the 3D gamma pass rate metric were used to assess the prediction accuracy.

Results

A strong correlation exist between body surface changes and dose changes (first canonical correlation coefficient = 0.950). For the dose deformation field and dose amplitude difference in the test set, the MSE of the predicted and actual values were 0.136 pixels and 0.229 cGy, respectively. After deforming the planning dose into a deformed one, the feature points’ Euclidean distance between it and the recalculated dose changes from 9.267 ± 1.879 mm to 0.456 ± 0.374 mm. The 3D gamma pass rate of 90% or higher for the 2 mm/2% criteria were achieved by 80.8% of all cases, with a minimum pass rate of 75.9% and a maximum pass rate of 99.6%. Pass rate for the 3 mm/2% criteria ranged from 87.8% to 99.8%, with 92.3% of the cases having a pass rate of 90% or higher.

Conclusions

This study provides a dosimetry method that is non‐invasive, real‐time, and requires no additional dose for breast cancer radiotherapy.
Generalized inhomogeneity‐resilient relaxation along a fictitious field (girRAFF) for improved robustness in rotating frame relaxometry at 3T
Authors: Coletti Chiara , Naaktgeboren Roeland , Tourais Joao , Van De Steeg‐Henzen Christal , Weingärtner Sebastian
Published: July 2024

Purpose

To optimize Relaxation along a Fictitious Field (RAFF) pulses for rotating frame relaxometry with improved robustness in the presence of and field inhomogeneities.

Methods

The resilience of RAFF pulses against and inhomogeneities was studied using Bloch simulations. A parameterized extension of the RAFF formulation was introduced and used to derive a generalized inhomogeneity‐resilient RAFF (girRAFF) pulse. RAFF and girRAFF preparation efficiency, defined as the ratio of the longitudinal magnetization before and after the preparation (), were simulated and validated in phantom experiments. and parametric maps were acquired at 3T in phantom, the calf muscle, and the knee cartilage of healthy subjects. The relaxation time maps were analyzed for resilience against artificially induced field inhomogeneities and assessed in terms of in vivo reproducibility.

Results

Optimized girRAFF preparations yielded improved preparation efficiency (0.95/0.91 simulations/phantom) with respect to RAFF (0.36/0.67 simulations/phantom). preparations showed in phantom/calf 6.0/4.8 times higher resilience to inhomogeneities than RAFF, and a 4.7/5.3 improved resilience to inhomogeneities. In the knee cartilage, (53 14 ms) was higher than (42 11 ms). Moreover, girRAFF preparations yielded 7.6/4.9 times improved reproducibility across / inhomogeneity conditions, 1.9 times better reproducibility across subjects and 1.2 times across slices compared with RAFF. Dixon‐based fat suppression led to a further 15‐fold improvement in the robustness of girRAFF to inhomogeneities.

Conclusions

RAFF pulses display residual sensitivity to off‐resonance and pronounced sensitivity to inhomogeneities. Optimized girRAFF pulses provide increased robustness and may be an appealing alternative for applications where resilience against field inhomogeneities is required.
Fecal incontinence is not associated with UTI: A contemporary case–control study
Authors: Stair Sabrina L. , Yoon Jamie H. , Dymanus Kyle A. , Lee Una J. , Adelstein Sarah A.
Published: July 2024

Introduction

Urinary tract infections (UTIs) are a leading cause of infection in adults. The most common cause is gastrointestinal bacteria ascending the urethra into the bladder. Studies showing fecal incontinence (FI) is a risk factor for UTI have been limited to nursing home populations. Healthy patients with recurrent UTI, especially women, often receive counseling, suggesting improper personal hygiene contributes to UTIs. This advice can be stigmatizing. Given UTI prevalence, it is important to elucidate risk factors for improved diagnosis, treatment, and patient education. Our objective was to perform a hospital‐centered, retrospective case‐control analysis to assess the effect of FI on UTI development in ambulatory patients.

Methods

Patients (n = 3035) with a diagnosis of FI were identified from a single institution and propensity score‐matched with screening colonoscopy patients (n = 3035) from 2018 to 2021. Patients were matched on age, sex, race, ethnicity, body mass index, and comorbidities, for example, diabetes, vesicoureteral reflux, and urinary incontinence. The association between FI and UTI was tested using Pearson's χ2 test.

Results

Median age was 64 years with more females than males (73.81% vs. 71.20% female for case/control, p = 0.02). Patients with FI were more often to have concurrent urinary incontinence (18.62% vs. 10.25% for case/control, p < 0.001), as well as specifically urgency incontinence (13.28% vs. 11.57% for case/control, p = 0.04). There was no significant difference in the incidence of UTI between patients with FI and those presenting for screening colonoscopy (p = 0.44).

Conclusion

FI was not associated with an increased number of UTIs. Based on our results, current stigmatizing beliefs regarding the association between FI and UTI should be reevaluated.
Slugs Count: Assessing citizen scientist engagement and development, and the accuracy of their identifications
Authors: Cavadino I. , Port G. , Mill A. , Clover G. , Roy H. E. , Jones H.
Published: July 2024

How accurately can citizen science participants identify species, and can the information they provide be used to calculate accurate estimates of species richness, abundance and diversity measures? In this paper, we address these questions using data from a citizen science project assessing slug species diversity in gardens.

Sixty participants were selected from over 2700 applicants across Britain to sample their gardens regularly for slugs following a standardised method. All slugs collected during the 30‐min search were posted to the lead investigator for verification throughout the 12‐month project. The resulting data were analysed to explore how accurate participants were in identifying slugs and whether this improved over the study period. Prior experience in slug identification was evaluated as a predictor of accuracy.

Participants overestimated slug abundance and species richness, which led to overestimates in species diversity indices, illustrating the importance of verification in citizen science projects involving identification.

Accuracy of slug identifications increased significantly over time in quantitative analysis of ecological data. However, self‐defined prior experience of identifying slugs before participation was not a good predictor of participant accuracy.

Participants reported perceived improvement in slug identification skills to an evaluation survey after the project. However, confidence in identifying and explaining identification of slugs was lower than confidence in understanding and explaining other new science topics.

This citizen science approach, including expert verification of physical specimens, illustrates how this method can be used successfully to provide accurate data on species' abundance and richness, alongside improving identification skills among the public for an understudied taxon. Continued engagement and feedback for participants is key in retaining citizen science participation in a project of this type, particularly if the taxon is challenging to identify correctly to species.

Read the free Plain Language Summary for this article on the Journal blog.
Role of reinforcement on the tribological properties of polytetrafluoroethylene composites: A comprehensive review
Authors: Deshwal Dhruv , Belgamwar Sachin U. , Bekinal Siddappa I. , Doddamani Mrityunjay
Published: July 2024

Polytetrafluoroethylene (PTFE) is widely used in tribological applications. However, it faces challenges due to its high wear rate. Reinforcement of additives in PTFE reduces its wear rate by up to 10,000 times in dry conditions. Infusing metallic filler materials like Al, Cu, and Pb improves PTFE wear performance but increases the coefficient of friction (COF). However, it may not be suitable for corrosive environments due to potential metal reactivity. Reinforcing PTFE composites with carbon‐based materials reduces weight, improves wear properties, and lowers COF. Pre‐treated materials enhance bonding for improved anti‐friction and anti‐wear properties. PTFE and its composites are widely used in journal bearings, bearing pads, and ball bearings due to their excellent low‐speed, low‐load lubrication properties. They outperform Babbitt alloy in bearing pads, except in heat conductivity. PTFE can also be used as a solid lubricant and can be combined with additives for improved performance. Apart from it, achieving an optimal combination of properties for all forms of reinforcement can be challenging due to the difficulty in determining exact values for multiple properties with specific types of reinforcement. This article provides a comprehensive review that delves into the significant findings pertaining to reinforcement and its application in bearing technology.

Highlights

Metals and carbon‐based fillers improve tribo‐properties.

Polytetrafluoroethylene (PTFE) provides lubrication and thermal stability to the polymeric materials.

Estimation of tribo‐thermal properties in combination is a challenge.

Testing conditions greatly impact PTFE composites performance.

PTFE as a solid lubricant suitable for low‐speed/load applications.
The Guanxi mediating role linking organizational justice to contextual performance with age as a moderator
Authors: Tan Lei , Guan Yi , Sheng Guojun
Published: July 2024

Guanxi, a distinctive Chinese concept, reflects a shared vision of relationships and connections that include mutual understanding, trust, and a deep bond between individuals. Recognized for its potency in shaping the relationships that facilitate business undertakings and access to key resources, Guanxi is postulated as a potential mediator in the nexus between organizational justice and contextual work performance. The depth of Guanxi, intertwined with Chinese culture and values, may be perceived differently across age groups. Specifically, as Chinese millennials usually interact with global paradigms, generational disparities might emerge in valuing these traditional constructs. This study delves into how the dimensions of Guanxi—Ganqing (emotional connection), Renqing (reciprocity), and Xinren (loyalty)—mediate the relationship between organizational justice and contextual work performance, with chronological age as a moderator. The present study includes a convenience sample of 630 Chinese employees, aged 22–67 years, who participated in a quantitative online survey. The findings endorse the mediation role of Guanxi. The total influence of justice was found to be significant, as well as the indirect impacts, that were statistically salient. Although the age‐moderated mediation was not wholly substantiated, the age‐specific indirect effects of Renqing and Xinren did present significant variances between millennials and those above 42 years. The relevance of this study extends beyond the academic field, shedding light on the cultural dynamics at play within Chinese organizational settings. By unveiling the relationships between Guanxi, organizational justice, and performance, and by elucidating the age‐specific variations therein, this research provides insights for organizational leaders and human resource professionals. Based on these findings, businesses can craft targeted interventions that capitalize on the strengths of Guanxi, ensuring fair practices and enhancing performance across diverse age groups. Further, recognizing the unique attributes and values of different generational cohorts can aid in fostering a harmonious, culturally attuned, and efficient workplace environment.
Insulated π‐Conjugated Azido Scaffolds for Stepwise Functionalization via Huisgen Cycloaddition on Metal Oxide Surfaces
Authors: Jiang Qi‐Chun , Iwai Tomohiro , Jo Morihiro , Hosomi Takuro , Yanagida Takeshi , Uchida Ken , Hashimoto Kazuki , Nakazono Takashi , Yamada Yusuke , Kobayashi Atsushi , Takizawa Shin‐ya , Masai Hiroshi , Terao Jun
Published: July 2024

In organic−inorganic hybrid devices, fine interfacial controls by organic components directly affect the device performance. However, fabrication of uniformed interfaces using π‐conjugated molecules remains challenging due to facile aggregation by their strong π‐π interaction. In this report, a π‐conjugated scaffold insulated by covalently linked permethylated α‐cyclodextrin moiety with an azido group is synthesized for surface Huisgen cycloaddition on metal oxides. Fourier‐transformed infrared (FT‐IR) spectroscopy and X‐ray photoelectron spectroscopy confirm the successful immobilization of the insulated azido scaffold on ZnO nanowire array surfaces. Owing to the highly independent immobilization, the scaffold allows rapid and complete conversion of the surface azido group in Huisgen cycloaddition reactions with ethynyl‐terminated molecules, as confirmed by FT‐IR spectroscopy monitoring. Cyclic voltammetry analysis of modified indium tin oxide substrates shows the positive effects of cyclic insulation toward suppression of intermolecular interaction between molecules introduced by the surface Huisgen cycloaddition reactions. The utility of the scaffold for heterogeneous catalysis is demonstrated in electrocatalytic selective O2 reduction to H2O2 with cobalt(II) chlorin modified fluorine doped tin oxide electrode and photocatalytic H2 generation with iridium(III) dye‐sensitized Pt‐loaded TiO2 nanoparticle. These results highlight the potential of the insulated azido scaffold for a stepwise functionalization process, enabling precise and well‐defined hybrid interfaces.
The interplay of intelligent manufacturing, innovation equilibrium and cost stickiness in the artificial intelligence era
Authors: Wang Fang , Li Qiang , Chen Hong
Published: July 2024

This study investigates the impact of intelligent manufacturing methods driven by artificial intelligence (AI) on cost stickiness in Chinese manufacturing enterprises. Leveraging the ABJ model， a regression analysis explores how different AI‐enabled intelligent manufacturing approaches influence cost stickiness through the lens of innovation equilibrium. The sample comprises manufacturing companies listed on China's A‐share market from 2013 to 2021. The findings reveal a negative correlation between intelligent manufacturing adoption and cost stickiness among these firms. Specifically, production‐based intelligent manufacturing exhibits a more significant effect on reducing cost stickiness compared with collaborative intelligent manufacturing methods. Moreover, intelligent manufacturing positively impacts both joint equilibrium innovation and matching equilibrium innovation. While joint equilibrium innovation is negatively associated with cost stickiness, matching equilibrium innovation shows no significant relationship with cost stickiness. The results indicate that innovation equilibrium plays a mediating role in the relationship between AI‐driven intelligent manufacturing and cost stickiness. Overall, this research sheds light on how AI capabilities enabling intelligent manufacturing processes and innovation equilibrium dynamics can help alleviate cost stickiness issues faced by manufacturing enterprises. It highlights the strategic value of adopting AI systems to enhance operational efficiency and cost management flexibility within manufacturing contexts.
soid: A Tool for Legal Accountability for Automated Decision Making
Authors: Judson Samuel , Elacqua Matthew , Cano Filip , Antonopoulos Timos , Könighofer Bettina , Shapiro Scott J. , Piskac Ruzica
Published: July 2024

We present $$\textsf{soid}$$
soid
, a tool for interrogating the decision making of autonomous agents using SMT-based automated reasoning. Relying on the Z3 SMT solver and KLEE symbolic execution engine, $$\textsf{soid}$$
soid
allows investigators to receive rigorously proven answers to factual and counterfactual queries about agent behavior, enabling effective legal and engineering accountability for harmful or otherwise incorrect decisions. We evaluate $$\textsf{soid}$$
soid
qualitatively and quantitatively on a pair of examples, i) a buggy implementation of a classic decision tree inference benchmark from the explainable AI (XAI) literature; and ii) a car crash in a simulated physics environment. For the latter, we also contribute the $$\textsf{soid}\hbox {-}\!\textsf{gui}$$

soid
-

gui

, a domain-specific, web-based example interface for legal and other practitioners to specify factual and counterfactual queries without requiring sophisticated programming or formal methods expertise.
Certified Robust Accuracy of Neural Networks Are Bounded Due to Bayes Errors
Authors: Zhang Ruihan , Sun Jun
Published: July 2024

Adversarial examples pose a security threat to many critical systems built on neural networks. While certified training improves robustness, it also decreases accuracy noticeably. Despite various proposals for addressing this issue, the significant accuracy drop remains. More importantly, it is not clear whether there is a certain fundamental limit on achieving robustness whilst maintaining accuracy. In this work, we offer a novel perspective based on Bayes errors. By adopting Bayes error to robustness analysis, we investigate the limit of certified robust accuracy, taking into account data distribution uncertainties. We first show that the accuracy inevitably decreases in the pursuit of robustness due to changed Bayes error in the altered data distribution. Subsequently, we establish an upper bound for certified robust accuracy, considering the distribution of individual classes and their boundaries. Our theoretical results are empirically evaluated on real-world datasets and are shown to be consistent with the limited success of existing certified training results, e.g., for CIFAR10, our analysis results in an upper bound (of certified robust accuracy) of 67.49%, meanwhile existing approaches are only able to increase it from 53.89% in 2017 to 62.84% in 2023.
Unifying Qualitative and Quantitative Safety Verification of DNN-Controlled Systems
Authors: Zhi Dapeng , Wang Peixin , Liu Si , Ong C.-H. Luke , Zhang Min
Published: July 2024

The rapid advance of deep reinforcement learning techniques enables the oversight of safety-critical systems through the utilization of Deep Neural Networks (DNNs). This underscores the pressing need to promptly establish certified safety guarantees for such DNN-controlled systems. Most of the existing verification approaches rely on qualitative approaches, predominantly employing reachability analysis. However, qualitative verification proves inadequate for DNN-controlled systems as their behaviors exhibit stochastic tendencies when operating in open and adversarial environments. In this paper, we propose a novel framework for unifying both qualitative and quantitative safety verification problems of DNN-controlled systems. This is achieved by formulating the verification tasks as the synthesis of valid neural barrier certificates (NBCs). Initially, the framework seeks to establish almost-sure safety guarantees through qualitative verification. In cases where qualitative verification fails, our quantitative verification method is invoked, yielding precise lower and upper bounds on probabilistic safety across both infinite and finite time horizons. To facilitate the synthesis of NBCs, we introduce theirk-inductive variants. We also devise a simulation-guided approach for training NBCs, aiming to achieve tightness in computing precise certified lower and upper bounds. We prototype our approach into a tool called and showcase its efficacy on four classic DNN-controlled systems.
Collective Contracts for Message-Passing Parallel Programs
Authors: Luo Ziqing , Siegel Stephen F.
Published: July 2024

Procedure contracts are a well-known approach for specifying programs in a modular way. We investigate a new contract theory for collective procedures in parallel message-passing programs. As in the sequential setting, one can verify that a procedure f conforms to its contract using only the contracts, and not the implementations, of the collective procedures called by f. We apply this approach to C programs that use the Message Passing Interface (MPI), introducing a new contract language that extends the ANSI/ISO C Specification Language. We present contracts for the standard MPI collective functions, as well as many user-defined collective functions. A prototype verification system has been implemented using the CIVL model checker for checking contract satisfaction within small bounds on the number of processes.
Entanglement structures from modified IR geometry
Authors: Ju Xin-Xiang , Lai Teng-Zhou , Liu Bo-Hao , Pan Wen-Bin , Sun Ya-Wen
Published: July 2024

Abstract

We investigate a new proposal connecting the geometry at various radial scales in asymptotic AdS spacetime with entanglement structure at corresponding real-space length scales of the boundary theory. With this proposal, the bulk IR geometry encodes the long-scale entanglement structure of the dual quantum system. We consider two distinct types of IR geometries, namely the spherical case and the hyperbolic case, which are intimately related to the physics of differential entropy and brane-world holography separately. We explore the corresponding change in the dual long-scale entanglement structures, utilizing the tools of the Ryu-Takayanagi formula, conditional mutual information, and partial entanglement entropy. The results indicate that modifying the IR geometry leads to a redistribution of entanglement at scales longer than a critical length determined by the location of the IR region, with the two modified IR geometries corresponding to two opposite ways of redistribution. Furthermore, we establish the maximum amount of entanglement that can be modified, which is proportional to the area of the IR region.
A two parameter family of lightcone-like hyperbolic string vertices
Authors: Bernardes Vinícius , Portugal Ulisses
Published: July 2024

Abstract

We introduce a two parameter family of string field theory vertices, which we refer to as hyperbolic Kaku vertices. It is defined in terms of hyperbolic metrics on the Riemann surface, but the geometry is allowed to depend on inputs of the states. The vertices are defined for both open and closed strings. In either case, the family contains the hyperbolic vertices. Then we show that the open string lightcone vertex is obtained as the flat limit of the hyperbolic Kaku vertices. The open string Kaku vertices, which interpolate between the Witten vertex and the open string lightcone vertex, is also obtained as a flat limit. We use the same limit on the case of closed strings to define the closed string Kaku vertices: a one parameter family of vertices that interpolates between the polyhedral vertices — which are covariant, but not cubic — and the closed string lightcone vertex — which is cubic, but not Lorentz covariant.
First constraints on the Lμ − Lτ explanation of the muon g-2 anomaly from NA64-e at CERN
Authors: Andreev Yu. M. , Antonov A. , Banerjee D. , Banto Oberhauser B. , Bernhard J. , Bisio P. , Celentano A. , Charitonidis N. , Cooke D. , Crivelli P. , Depero E. , Dermenev A. V. , Donskov S. V. , Dusaev R. R. , Enik T. , Frolov V. N. , Gardikiotis A. , Gertsenberger S. V. , Girod S. , Gninenko S. N. , Hösgen M. , Kachanov V. A. , Kambar Y. , Karneyeu A. E. , Kasianova E. A. , Kekelidze G. , Ketzer B. , Kirpichnikov D. V. , Kirsanov M. M. , Kolosov V. N. , Kramarenko V. A. , Kravchuk L. V. , Krasnikov N. V. , Kuleshov S. V. , Lyubovitskij V. E. , Lysan V. , Marini A. , Marsicano L. , Matveev V. A. , Mena Fredes R. , Mena Yanssen R. , Molina Bueno L. , Mongillo M. , Peshekhonov D. V. , Polyakov V. A. , Radics B. , Salamatin K. , Samoylenko V. D. , Sieber H. , Shchukin D. , Soto O. , Tikhomirov V. O. , Tlisova I. , Toropin A. N. , Tuzi M. , Ulloa P. , Volkov P. V. , Volkov V. Yu. , Voronchikhin I. V. , Zamora-Saá J. , Zhevlakov A. S.
Published: July 2024

Abstract

The inclusion of an additional U(1) gauge Lμ − Lτ symmetry would release the tension between the measured and the predicted value of the anomalous muon magnetic moment: this paradigm assumes the existence of a new, light Z′ vector boson, with dominant coupling to μ and τ leptons and interacting with electrons via a loop mechanism. The Lμ − Lτ model can also explain the Dark Matter relic abundance, by assuming that the Z′ boson acts as a “portal” to a new Dark Sector of particles in Nature, not charged under known interactions. In this work we present the results of the Z′ search performed by the NA64-e experiment at CERN SPS, that collected ~ 9 × 1011 100 GeV electrons impinging on an active thick target. Despite the suppressed Z′ production yield with an electron beam, NA64-e provides the first accelerator-based results excluding the g − 2 preferred band of the Z′ parameter space in the 1 keV <$$ {m}_{Z^{\prime }} $$

m

Z
′

≲ 2 MeV range, in complementarity with the limits recently obtained by the NA64-μ experiment with a muon beam.
Searching for a new light gauge boson with axial couplings in muon beam dump experiments
Authors: Fayet Pierre , Olea-Romacho María Olalla
Published: July 2024

Abstract

We present a formalism for new U(1) interactions involving weak hypercharge, baryon, and lepton numbers, and a possible axial symmetry generator FA in the presence of a second Brout-Englert-Higgs doublet. The resulting U boson, after mixing with the Z, interpolates between a generalised dark photon, a dark Z, and an axially coupled gauge boson. We especially focus on the axial couplings originating from FA or from mixing with the Z, determined by the scalar sector via parameters like tan β and the v.e.v. of an extra dark singlet.

We explore the distinctive features of axially coupled interactions, especially in the ultrarelativistic limit, where the U boson behaves much as an axion-like particle, with enhanced interactions to quarks and leptons. This enhancement is particularly relevant for future muon beam dump experiments, since the muon mass considerably increases the effective coupling, proportional to 2mμ/mU, compared to analogous experiments with electrons.

We also analyse the shape of the expected beam dump exclusion or discovery regions, influenced by U boson interactions and the experiment geometry. Different situations are considered, limited in particular by cases for which the U decays before reaching the detector, or has too small couplings to produce detectable events. We also compare to vectorially coupled bosons and axion-like pseudoscalars, highlighting the importance of understanding the parameter space for future experiment design and optimisation.
Non-relativistic intersecting branes, Newton-Cartan geometry and AdS/CFT
Authors: Lambert Neil , Smith Joseph
Published: July 2024

Abstract

We discuss non-relativistic variants of four-dimensional $$ \mathcal{N} $$
N
= 4 super-Yang-Mills theory obtained from generalised Newton-Cartan geometric limits of D3-branes in ten-dimensional spacetime. We argue that the natural interpretation of these limits is that they correspond to non-relativistic D1-branes or D3-branes intersecting the original D3-branes. The resulting gauge theories have dynamics that reduce to quantum mechanics on monopole moduli space or two-dimensional sigma-models on Hitchin moduli space respectively. We show that these theories possess interesting infinite-dimensional symmetries and we discuss the dual AdS geometries.
The Role of Self-Management in Pessary Therapy for Pelvic Organ Prolapse—A retrospective cohort study
Authors: Paulussen Evy , Börger Renée , van Eijndhoven Hugo , Engberts Marian , Steures Pieternel , Weemhoff Mirjam
Published: July 2024

Introduction and Hypothesis

This study investigated pessary self-management (PSM). The primary outcome was how often PSM was taught to patients with pelvic organ prolapse (POP). Secondary outcomes were associations of PSM with treatment continuation, side effects, changing to surgery, and number of doctor consultations in the first year after treatment initiation compared with clinical management (CM).

Methods

A retrospective cohort study was conducted in 300 patients visiting three Dutch medical centres in 2019, and receiving a pessary for POP. The t test, Chi-squared test and logistic regression were performed to compare PSM with CM and to identify factors associated with treatment continuation.

Results

A total of 35% of patients received PSM instructions, of which 92% were able to perform PSM successfully. Treatment was continued by 83% of patients practicing PSM and 75% of patients having CM (p = 0.16), side effects occurred in 26% and 39% respectively (p = 0.18). Pain or discomfort was associated with treatment discontinuation (p < 0.01). In a subgroup analysis of patients who had a pessary suitable for PSM, treatment continuation was significantly higher in the PSM group (97%) than in the CM group (74%; p < 0.01).

Conclusions

Pessary self-management was only taught to 35% of patients who received a pessary, although the ability to perform PSM was high (92%). Treatment discontinuation was significantly lower in the PSM subgroup, when assessing the subgroup of patients using a pessary suitable for PSM. The large number of patients using a pessary suitable for PSM in the CM group implies that there is a lot to gain by promoting PSM.
Six-month follow-up of multidomain cognitive impairment in non-hospitalized individuals with post-COVID-19 syndrome
Authors: Schild Ann-Katrin , Scharfenberg Daniel , Regorius Anton , Klein Kim , Kirchner Lukas , Yasemin Goereci , Lülling Joachim , Meiberth Dix , Schweitzer Finja , Fink Gereon R. , Jessen Frank , Franke Christiana , Onur Oezguer A. , Jost Stefanie Theresa , Warnke Clemens , Maier Franziska
Published: July 2024

Some people infected with SARS-CoV-2 report persisting symptoms following acute infection. If these persist for over three months, they are classified as post-COVID-19 syndrome (PCS). Although PCS is frequently reported, detailed longitudinal neuropsychological characterization remains scarce. We aimed to describe the trajectory of cognitive and neuropsychiatric PCS symptoms. 42 individuals with persisting cognitive deficits after asymptomatic to mild/moderate acute COVID-19 at study inclusion received neuropsychological assessment at baseline (BL) and follow-up (FU; six months after BL). Assessments included comprehensive testing of five neurocognitive domains, two cognitive screening tests, and questionnaires on depression, anxiety, sleep, fatigue, and health-related quality of life. Results showed high rates of subjective cognitive complaints at BL and FU (95.2% versus 88.1%) without significant change over time. However, objectively measured neurocognitive disorder (NCD) decreased (61.9% versus 42.9%). All cognitive domains were affected, yet most deficits were found in learning and memory, followed by executive functions, complex attention, language, and perceptual motor functions. In individuals with NCD, the first three domains mentioned improved significantly over time, while the last two domains remained unchanged. Cognitive screening tests did not prove valuable in detecting impairment. Neuropsychiatric symptoms remained constant except for quality of life, which improved. This study emphasizes the importance of comprehensive neuropsychological assessment in longitudinal research and provides valuable insights into the trajectory of long-term neuropsychological impairments in PCS. While cognitive performance significantly improved in many domains, neuropsychiatric symptoms remained unchanged.