bluuebunny/crossref_metadata_2025 huggingface dataset:
Technical note: Workload and transmission data for mobile C‐arm fluoroscopy in gastrointestinal endoscopy
Authors: Li Xinhua , Marschall Theodore A. , Yang Kai , Liu Bob
Published: February 2024

Background

Mobile C‐arms may be used in fixed locations, and it is recommended that qualified experts evaluate structural shielding.

Purpose

To assess clinical workload distributions for mobile C‐arms used in gastrointestinal endoscopy and determine the Archer equation parameters for the C‐arm beam spectra.

Methods

Consecutive (30 months) gastrointestinal endoscopic procedures on two Cios Alpha systems (Siemens) were retrospectively analyzed. X‐ray tube voltage, tube current‐time product, reference point air kerma (Ka,r), air kerma‐area product (PKA), and fluoroscopic time were examined. The primary beam half‐value layer (HVL) was measured with an ionization chamber and aluminum 1100 plates. Stray radiation fraction at 1 m from a scattering source (ACR R/F phantom) was directly measured. Monte Carlo (Geant4) simulation was performed to calculate the transmission of broad X‐ray beams through lead, concrete, gypsum, and steel, with X‐ray HVLs matching those of the C‐arm X‐ray beam. The transmission data were fitted to the Archer equation.

Results

The number of procedures (3509) was equivalent to 13.48 procedures per room per week. Dose quantities were 54.8 mGy (Ka,r), 18.3 Gy∙cm2 (PKA), and 7.8 min (fluoroscopic time) per procedure. X‐ray beam irradiation events were recorded for 2906 (82.8%) procedures with 160,009 events, whose mA‐minute weighted tube voltage was 91.0 kV and the workload was 0.68 mA‐minute per procedure. The two rooms had a significant difference in the number of procedures per week, 17.3 (29) [mean (maximum)] and 9.6 (16), respectively. The stray radiation fraction was 9.7×10−4 (80 kV) and 1.25×10−3 (120 kV). Transmission fitting parameters were provided for the tube voltage (on average, 90 kV; high end, 120 kV) of the C‐arm.

Conclusions

This work provides workload and transmission data for mobile C‐arm fluoroscopy in gastrointestinal endoscopy, which indicates a need for structural shielding evaluation of the procedure rooms.
Effects of different mass ratios on mechanical properties and impact energy release characteristics of Al/PTFE/W and Al/PTFE/CuO polymer composites
Authors: Xu Xiangchun , Fang Hongjie , Chen Rong , Yu Kun
Published: February 2024

Aluminum/polytetrafluoroethylene (Al/PTFE) is an impact‐initiated material that is extensively utilized in military and civilian applications due to its insensitivity, high energy density and ease of manufacturing. To increase both its compressive strength and energy density, Al/PTFE was doped with various amounts of W and CuO particles. These polymer composites exhibit elastoplastic properties, as well as significant strain hardening and strain‐rate hardening during compression deformation. At a strain rate of 5000 s−1, the compressive strength of the Al/PTFE/W and Al/PTFE/CuO specimens with an additive content of 30% reaches a peak of 194.1 and 189.2 MPa, which corresponds to an increase of 40.3% and 36.8%, respectively, compared with the compressive strength of Al/PTFE (138.3 MPa). The homogeneous bonding strength between the additives and PTFE and the fact that the elastic PTFE nanofibers inhibit the extension of microcracks are the main mechanical strengthening mechanisms. The reaction of the composites under high‐speed impact is violent and accompanied by sputtering sparks, and the reaction efficiency was determined using an improved drop‐hammer apparatus. As the W content increases, the impact reactivity of Al/PTFE/W decreases monotonically. However, as CuO content increases, the reaction intensity of Al/PTFE/CuO initially increases, and then decreases. At a CuO content of 30%, the energy release efficiency of Al/PTFE/CuO reaches its maximum (10.49%), which is 84.4% higher than that of Al/PTFE. TG‐DSC and XRD tests were performed to analyze the pyrolysis process and elucidate the reaction mechanism. A gas–solid chemical reaction model was developed, and the reactivity arises from multiple factors.

Highlights

Typical elastoplastic characteristics as well as strain hardening and strain‐rate hardening were observed.

The mechanical strengthening effect of W particles is higher than that of CuO particles of Al/PTFE specimen.

The addition of W particles decreases the impact reactivity, but the addition of CuO particles improves the energy density of Al/PTFE.

The reaction efficiency of Al/PTFE/CuO reaches a peak of 10.49%, which increased by 84.4% compared with that of Al/PTFE.
Carbon fiber reinforced composites with self‐sensing and self‐healing capabilities enabled by CNT‐modified nanofibers
Authors: Wan Wenhu , Shen Rulin , Tang Juntao , Xu Yangbo , Zou Xiangfu , Guo Haibo
Published: February 2024

Carbon fiber reinforced polymer (CFRP) composites with self‐sensing and self‐healing capabilities was developed in this work. Uniform dispersion of CNTs within a core‐shell nanofiber structure was achieved through a combination of electrospinning and subsequent surface spraying of CNTs. The resulting core‐shell nanofibers were incorporated into CFRP composites using a vacuum‐assisted resin transfer molding process. Mechanical testing demonstrated improved mechanical properties in the composites treated with CNT spraying. Real‐time, precise monitoring of structural damage was enabled through the measurement of electrical signal changes caused by composite deformation in static loading experiments. Furthermore, self‐healing experiments demonstrated that the thermally conductive network formed by CNTs facilitated more uniform heat transfer within the composites. During the healing process, resistive heating of damaged specimens was applied, resulting in a remarkable healing efficiency of 95.2%. The experiments indicate that the composite developed in this paper possess excellent self‐sensing and self‐healing capabilities.

Highlights

Damage self‐sensing and self‐healing CFRP composites were developed.

CNTs‐modified nanofibers were applied to endow the composite specific abilities.

Resistivity signals were collected for real‐time damage monitoring.

The self‐healing efficiency of the designed composite reached up to 95.2%.

Self‐sensing and self‐healing occurred autonomously within closed‐loop structure.
Experimental investigation on the mechanical and acoustic performance of hemp/kenaf hybrid composites: Influence of different stacking sequences
Authors: Arshad Muhammad Nadeem , Thiagamani Senthil Muthu Kumar , Jeyaguru Sangilimuthukumar , Muthukumar Chandrasekar , Krishnasamy Senthilkumar , Subramaniam Jeyanthi , Khan Anish , Althomali Raed H.
Published: February 2024

This study investigated the effect of various stacking sequences on the mechanical and acoustic characteristics of hemp and kenaf fibers reinforced hybrid composites. The mechanical study was done by using universal testing machine and izod imact tester. Further, acoustic study was done by using impendence tube method. Hemp/kenaf/kenaf/hemp hybrid laminates outperformed the other composites in terms of tensile strength, flexural strength and impact strength. In the mono reinforcements, hemp/epoxy composites demonstrated superior mechanical characteristics than the epoxy matrix and kenaf/epoxy composites. However, hybrid composites have superior mechanical behavior compared to pure composites. From the acoustic results revealed that the pure hemp and kenaf/hemp/hemp/kenaf hybrid composites exhibitted highest sound transmission loss level at lowest and highest frequency region. The bestmechanical characteristics of hybrid composites will be suggested for use in automobile door panels. Also, the optimal sound transmission coefficent values signifying their appropriateness for use in applications that encompass many frequency bands.

Highlights

Hybridization of kenaf/hemp fibers

Improved mechanical properties over the single fiber composites

Better acoustic properties
The curious case of the colored crystals of N‐substituted 2‐oxo‐1,2‐dihydropyridinyl‐3‐yl amines and amides: Self‐association in the solid state
Authors: Loughlin Wendy A. , Jenkins Ian D. , Healy Peter C. , Karis N. David , Pierens Gregory K.
Published: February 2024

During a previous investigation of pyridone derivatives as inhibitors of glycogen phosphorylase, we observed that some N‐substituted 2‐oxo‐1,2‐dihydropyridinyl‐3‐yl amines and amides exhibited different colors, ranging from red to green to blue to teal. Remarkably, one compound (compound 8) could be crystallized in both a red form and a green form. To try to understand these observations, we have carried out further spectroscopic studies in the solid state and in solution employing UV‐visible spectroscopy, NMR spectroscopy, and X‐ray crystallography, along with molecular mechanics and DFT calculations on selected compounds. Evidence was obtained in the solid state for the self‐association of pyridones into dimeric complexes or near‐planar dimers induced by intermolecular hydrogen bonding and possible π‐stacking, whereas monomeric structures for two compounds were proposed in chloroform, in agreement with the DFT calculated chemical shifts. In this study, it was determined that the colors observed could not be attributed to hydrogen bonding or possible π‐bond stacking in the novel relatively unconjugated pyridone derivatives. A possible explanation for the colors is suggested: a contaminant formed by aerial oxidation of trace amounts of the 3‐aminopyridone starting material. This result contrasts with existing literature reports of UV and fluorescence spectra, which indicated distinct coloration for conjugated 2‐pyridone compounds. The spectroscopic results, including X‐ray structural data for five pyridones, contribute to a deeper understanding of structural interactions in pyridone derivatives.
Isoperimetric inequalities for real‐valued functions with applications to monotonicity testing
Authors: Black Hadley , Kalemaj Iden , Raskhodnikova Sofya
Published: February 2024

We generalize the celebrated isoperimetric inequality of Khot, Minzer, and Safra (SICOMP 2018) for Boolean functions to the case of real‐valued functions . Our main tool in the proof of the generalized inequality is a new Boolean decomposition that represents every real‐valued function over an arbitrary partially ordered domain as a collection of Boolean functions over the same domain, roughly capturing the distance of to monotonicity and the structure of violations of to monotonicity. We apply our generalized isoperimetric inequality to improve algorithms for testing monotonicity and approximating the distance to monotonicity for real‐valued functions. Our tester for monotonicity has query complexity , where is the size of the image of the input function. (The best previously known tester makes queries, as shown by Chakrabarty and Seshadhri (STOC 2013).) Our tester is nonadaptive and has 1‐sided error. We prove a matching lower bound for nonadaptive, 1‐sided error testers for monotonicity. We also show that the distance to monotonicity of real‐valued functions that are ‐far from monotone can be approximated nonadaptively within a factor of with query complexity polynomial in and the dimension . This query complexity is nearly optimal for nonadaptive algorithms even for the special case of Boolean functions (The best previously known distance approximation algorithm for real‐valued functions, by Fattal and Ron (TALG 2010) achieves ‐approximation.).
Enhancement of Ligand Immobilization on Gold Surface by Optimizing Monolayer Concentration and Pre‐Concentration Studies for Surface Plasmon Resonance Analysis of Rutin‐Lysozyme Interaction
Authors: Türkoğlu Emir Alper
Published: February 2024

Surface plasmon resonance (SPR) is a versatile tool for real time monitoring of molecular interactions, providing biophysical data such as affinity and kinetics. Rutin is found in various plants and fruits and is utilized in several industries. Because of its therapeutic and industrial importance, the binding of rutin to one of the major proteins found in blood and saliva, lysozyme (LZM), was investigated to determine the affinity constants of the rutin‐LZM interaction. Chicken egg white lysozyme (CEWLZM) was selected as a model ligand. 11‐mercaptoundecanoic acid (MUA) was chosen for the self‐assembled monolayer (SAM) design on the gold chip surface. After optimizing MUA concentration and pre‐concentration studies to enhance ligand immobilization, optimum MUA concentration in SAM formation, ideal running and coupling buffers, flow rate and ligand concentration were determined to perform SPR analysis. Various concentrations of rutin (20–300 μM) were injected into the SPR for kinetic analysis. The association (ka), dissociation (kd) rate constants, and equilibrium constant (KD) were calculated from the kinetics of the binding curves. SPR binding results indicated that the KD value of rutin‐CEWLZM binding was determined as 80.07±1.22 μM. This study demonstrates the binding affinity of rutin to CEWLZM, offering potential insights for medical and pharmaceutical sciences.
DNA tetrahedron as a carrier of doxorubicin for metastatic breast cancer treatment
Authors: Vaswani Payal , Naveena A Hema , Kansara Krupa , Dahle Landon , Kumar Ashutosh , Bhatia Dhiraj
Published: February 2024

Metastatic breast cancer is a significant clinical challenge calling for novel and efficient therapeutic approaches. DNA tetrahedron, a highly programmable nanocage, offers some promising attributes including biocompatibility, stability, and functionalization making it an attractive candidate for drug delivery. In this study, we have explored the potential of DNA tetrahedron as a carrier of doxorubicin, a DNA and RNA synthesis‐inhibiting chemotherapy drug. We have encapsulated doxorubicin in DNA tetrahedron (TD : Dox) and subsequently focused on metastatic breast cancer cells for the effect of the same. We showed that TD : Dox has the potential to inhibit the migration of cancerous cells in the 2D model and inhibit the invasion of tumor cells in the 3D model as well. This system also can be uptaken in in vivo zebrafish model as well. Overall, this study promises the TD : Dox system as an ideal drug delivery model and a viable approach for metastatic breast cancer treatment.
Talking About Digital Responsibility: Children’s and Young People’s Voices
Authors: Gudmundsdottir Greta Björk , Holmarsdottir Halla , Mifsud Louise , Teidla-Kunitsõn Gertha , Barbovschi Monica , Sisask Merike
Published: February 2024

This chapter delves into the prevailing discourse surrounding the digital generation and the role of digital technology in shaping their lives. We raise the pertinent question of whether the emphasis on connectivity overlooks aspects of digital responsibility and hinders online well-being. Drawing from interview data, we investigate how children in Estonia, Norway and Romania comprehend digital responsibility. We delve into themes such as online identity, integrity, interactions, critical evaluation of online content, copyright concerns, digital citizenship, rights and participation. The study highlights the necessity of developing digital responsibility as a means to navigate the intricate complexities and risks posed by digital technology. Through an analysis of interview data, we shed light on ethical, legal and attitudinal dimensions of digital responsibility. Our findings reveal that source awareness is closely linked to the cultivation of digital responsibility in school. Furthermore, we identify challenges posed by the ethical dimension, while recognising the influential role played by peers. In conclusion, we emphasise the importance of amplifying children’s voices, comprehending their perspectives and actively involving them in the process of fostering digital responsibility. By doing so, we recognise the indispensable role of their active engagement and strive to ensure their well-being and healthy digital lives.
Intersecting Knowledge on Young People’s Well-Being and Use of Digital Technology Across Contexts: A Scoping Review Synthesis
Authors: Seland Idunn
Published: February 2024

This literature review adds to the existing literature on the relationships between young people’s use of digital technology and their well-being by investigating how perceived excessive use of the Internet in one social setting may increase a person’s well-being in a different social setting. By combining clinical-psychological and digital literacy perspectives on well-being with a theoretical framework focussing on human vulnerability and the protective potential of human agency, the review’s thematic synthesis of 21 studies between 2011 and 2021 supports previous research suggesting that digital engagement can be a coping strategy for young people experiencing problems. First, the analysis examines how young people’s activity across social contexts represented by family, leisure, school and a digital space for democratic participation may affect their predefined roles as children or students, and how new possibilities for development and learning emerge. Second, the discussion combines the clinical-psychological and digital literacy perspectives for a deeper understanding of how young people’s agency may help them overcome different sources of vulnerability as obstacles to well-being. Thus, the review nuances the discussion on digital technology and well-being to understand what this technology represents to young people as they navigate, negotiate and struggle with the normal pitfalls of life.
Developing a Toolkit for Contributing to Digital Competence: A Review of Existing Resources
Authors: Bărbut¸ă Alina , Roth Maria
Published: February 2024

The variety and increased accessibility of digital technologies has accelerated and facilitated children and young people’s use of digital devices, but accelerated use can also lead to increased risk (Livingstone et al., 2017). Children and young people’s relationship with the digital world, their level of digital skills, and their opportunities to use devices and benefit from this use differ due to various issues and lead to inequalities related to access, literacy and engagement (Helsper, 2021). To reduce these inequalities and help support children and young people to navigate competently, safely, creatively and critically in the digital world, there is a need for strategies, policies, resources and guidelines to inform and support them. This chapter explores the results of a scoping review aimed at assessing guidelines and toolkits for supporting children and young people’s use of digital technology. The analysis reveals the existence of a large pool of resources available not only for children and young people but also for their parents and teachers. At the same time, the analysis shows a gap in toolkits supporting children and young people's communication with their parents and other adults.
EU Policy Reflections on the Intersections Between Digital and Social Policies Supporting Children as Digital Citizens
Authors: Shorey Holly
Published: February 2024

This chapter analyses EU digital and social inequalities and rights-based policies from the early 2010s–2020s to explore how policies are evolving to further reflect how digital technologies are embedded in children’s everyday realities. Progress made to bring the social lens into digital policymaking and the digital dimension into social and rights-based policies is highlighted whilst places are identified for further integration. In the early 2010s, EU policies focused on child safety concerns without taking a holistic approach to how digitalisation interacts with children’s rights. Policymakers were concerned with whether children should be granted access to the digital world rather than how. Today’s children’s social environments increasingly have a digital dimension, one that brings home, school, family, and civic participatory spaces together. The more integrated digital technologies become in children’s lives, the more key it is that policymakers take a social inequalities approach to ensure that the digital environment acts as a venue for children’s rights and not a point of further division. To respond to this reality, policy frameworks must reflect the porous boundaries opening up between policy areas. Digital policies and social and rights-based policies must recognise the intersections between these fields to the digital generation.
Discourses and Gender Divides in Children’s Digital Everyday Lives
Authors: Wilhelmsen Janniche Elisabeth Broch , Lafton Tove
Published: February 2024

In this qualitative study, we seek to contribute knowledge about how children talk about their digital everyday lives in peer groups and how boys and girls talk about it differently. The empirical material consists of transcripts taken from five focus group interviews with Norwegian children aged eight to ten. We use a Foucauldian-inspired discursive approach by analyzing how the participants position children, including themselves (with their spoken words), as subjects toward (spoken) objects connected to digital technology, and we identify eight different approaches when the participants talk about themselves (and other children) as subjects in relation to digital technology. Six of the ways the participants talk about children are gendered and the main difference we find is that the girls present themselves as more connected to their parents and present themselves as aware of negative content online, while the boys are either very cheeky or present themselves as sensible and social in their online activities. In the discussion we examine the findings as part of dominating discourses. We discuss if different expectations according to gender can be linked to girls not exploiting the learning potential of technology in the same way as boys do and whether boys do not have the same opportunities as girls to come to their parents with their negative online experiences.
ASTRA, A Transition Density Matrix Approach to the Interaction of Attosecond Radiation with Atoms and Molecules
Authors: Randazzo Juan M. , Marante Carlos , Chattopadhyay Siddhartha , Gharibnejad Heman , Schneider Barry I. , Olsen Jeppe , Argenti Luca
Published: February 2024

A new formalism and computer code, ASTRA (AttoSecond TRAnsitions), has been developed to treat the interactions of short, intense radiation with molecules. The formalism makes extensive use of transition density matrices, computed using a state-of-the-art quantum chemistry code (LUCIA), to efficiently calculate the many-body inter-channel-coupling interactions required to simulate the highly correlated electron dynamics due to atoms and molecules exposed to attosecond laser radiation.
Simulating Strong Field Tunnel Ionization of Molecules
Authors: Ortmann L. , AlShafey A. , Staudte A. , Landsman A. S.
Published: February 2024

Recently we introduced a method to quantify the relative contribution of upfield versus downfield ionization when a diatomic molecule is exposed to intense infrared light [1]. Applying this to previously measured electron momenta distributions following strong field ionization of N2, we found approximately a 2∶1 ratio of electrons ionized from a downfield atom, relative to upfield. This suggests that the bound state wave function largely adapts adiabatically to the changing laser field, although the nonadiabatic process of ionization enhancement still contributes significantly even in neutral molecules. Here, we discuss the Quantum Trajectory Monte Carlo (QTMC) used to simulate electron trajectories, and explore possible modifications of the model [1].
Control of Photoelectron-Ion Entanglement in Attosecond Laser-Induced Photoionization of H2
Authors: Koll Lisa-Marie , Witting Tobias , Vrakking Marc J. J.
Published: February 2024

We report experiments where vibrational wave packets are produced in H2+ by the ionization of neutral H2 by a sequence of two phase-locked attosecond pulse trains (APTs) with a variable time delay. Changes in the degree of vibrational coherence in the H2+ cation with the XUV-XUV time delay can be explained in terms of the dependence of the degree of ion+photoelectron entanglement on the two-pulse delay.
Ultrafast Second-Harmonic XUV Spectroscopy: A Novel Probe for Symmetry
Authors: Zuerch Michael
Published: February 2024

Extreme-ultraviolet second-harmonic generation spectroscopy (XUV-SHG) is a novel spectroscopy that enables probing element-selective symmetry-broken states. This renders XUV-SHG especially useful to study surfaces, interfaces, and symmetry-broken bulk states in otherwise complex chemical environments. In a string of recent works, XUV-SHG was successfully applied to study the role of lithium in various compounds. One of the most striking recent results studied the role of Li symmetry-breaking displacement causing the emergence of polarity in the polar metal LiOsO3. Furthermore, the directional dependence of the SHG process allows geometry specific measurements. Given the femtosecond nature of the probe pulses, one can readily envision this method to be applied to study interfacial carrier dynamics in complex in-operando environments that are difficult to probe with conventional ultrafast methods.
Attosecond Core-Exciton Dynamics in Wide-Gap Insulators
Authors: Inzani Giacomo , Sato Shunsuke A. , Lucarelli Giacinto D. , Moio Bruno , Borrego-Varillas Rocío , Frassetto Fabio , Poletto Luca , Hübener Hannes , Giovannini Umberto De , Rubio Angel , Nisoli Mauro , Lucchini Matteo
Published: February 2024

An option to overcome the limits of electronics are excitons, quasi-particles generated by the electron-hole Coulomb interaction. A fundamental prerequisite is the possibility to control their properties with optical fields. We adopted attosecond reflection spectroscopy to investigate the interplay between core excitons and ultrashort infrared pulses in MgF$${ }_2$$

2

. Their ultrafast response is divided into two contributions, unfolding on different time scales, related to the exciton dual nature. Namely, we discern the atomic-like behaviour, dominating the few-femtosecond response, from the excitonic solid-like characteristics, with sub-femtosecond timing. Theoretical models highlight the role of the exciton binding energy in dictating their optical response.
Increase in Photon Flux of Attosecond Pulses
Authors: Xue Bing , Nishimura Kotaro , Takahashi Eiji J. , Midorikawa Katsumi
Published: February 2024

High-intensity attosecond pulses capable of inducing a two-photon process are desired to realize an attosecond pump–attosecond probe experiment. In this work, we show the increase of the intensity of attosecond pulses in the water-window region by combining a loose focusing method with high-energy mid-IR drivers. Meanwhile, the effectiveness of an ideal driving field waveform produced by a multi-wavelength synthesizer is demonstrated to improve the conversion efficiency.
Imaging Ultrafast Dissociation Dynamics: OCS & Roaming in Formaldehyde
Authors: Endo Tomoyuki , Neville Simon P. , Ziems Karl Michael , Lassonde Philippe , Qu Chen , Schmidt Bruno E. , Fujise Hikaru , Fushitani Mizuho , Hishikawa Akiyoshi , Gräfe Stefanie , Houston Paul L. , Bowman Joel M. , Schuurman Michael S. , Légaré François , Ibrahim Heide
Published: February 2024

Upon photoexcitation, molecules break apart, following different dissociation reactions. We can image these dissociation pathways using Coulomb explosion imaging (CEI) and sometimes we can control them using asymmetric laser fields. In the formaldehyde molecule, we can see fragments following the direct, conventional dissociation path, as well as fragments deviating from this minimum energy path. So-called roaming fragments or “roamers” explore the potential energy landscape in a statistical manner and could be directly captured in real-time, despite the signal’s statistical character. This is possible due to the single-molecule sensitivity of CEI and we could show that the onset of roaming occurs actually several orders of magnitude earlier than previously expected. In the polar molecule OCS we go one step further by controlling the fragmentation process using two-color asymmetric laser fields. In addition to expected direct ionization effects, we also see post-ionization contributions, which are usually not visible in heavy polar molecules. We thus show in two different examples that CEI provides the means to extract new, unexpected pathways, which would otherwise remain hidden underneath a strong background.
Augmentation of Cardiac Ischemic Geometry for Improving Machine Learning Performance in Arrhythmic Risk Stratification
Authors: Bertrand Ambre , Yamamoto Carolyna , Monopoli Giulia , Schrotter Thomas , Myklebust Lena , Uv Julie J , Arevalo Hermenegild J , Maleckar Mary M
Published: February 2024

Ventricular arrhythmias frequently occur as a complication of myocardial infarction (MI), due to significant changes in the heart’s structure and electrophysiology. If left untreated, these alterations may lead to sudden cardiac death (SCD). It is therefore critical to evaluate risk prediction accurately in post-infarction patients to enable early intervention and improve patient outcomes. This work introduces a novel approach to improve arrhythmia risk assessment in post-infarction patients. We propose a new pipeline to build physiologically realistic image-based models of patient hearts, producing more realistic meshes compared to publicly available pipelines. We generate a library of 90 cardiac geometries of MI patients and use these cardiac models to estimate likelihood of reentry using electrophysiological (EP) simulations. However, due to the computationally expensive nature of this approach, we also introduce a data augmentation pipeline to train a machine learning (ML) model for risk stratification, enabling accurate and real-time prediction of the simulation outcomes. Our trained ML model achieved an accuracy of 88.0% and F1 score of 48%, with a prediction time of 0.01 seconds per case (compare with approximately 5 hours per case for EP simulations). In conclusion, the work presented here improved the accuracy of personalised biventricular geometries, introduced a novel data augmentation approach for scar distribution, and decreased prediction time of risk of arrhythmias post-MI by more than five orders of magnitude.
Impact of Modeling Assumptions on Hemodynamic Stresses in Predicting Cerebral Aneurysm Rupture Status
Authors: Nozaleda Guillermo L , Poloni Sofia , Soliveri Luca , Valen-Sendstad Kristian
Published: February 2024

Approximately 3% of the population is estimated to have cerebral aneurysms, which are the leading cause of subarachnoid haemorrhage. Convincing evidences suggest that wall shear stresses (WSS) play a role in vessel remodeling and in the development of vascular diseases. SinceWSS cannot be directly measured, researchers have resorted to using medical images available in routine clinical practice to simulate computational fluid dynamics (CFD) and investigate patient-specific vascular conditions. They retrospectively analyse the correlation between WSS and disease outcomes to find potential clinical tools for future use. However, most of these models are based on assumptions that introduce variability and error. In this work we investigated the effects of a non-Newtonian viscosity model and inflow uncertainty on the prediction of commonly computed hemodynamic metrics. Our results show a substantial influence of the non-Newtonian model and blood flow rate on CFD outcomes, highlighting the need of incorporating non-Newtonian rheology and patient-specific blood flow measurements in CFD simulations.
Capital Networks and Early Papermaking
Authors: Ehrich Martha Emilie
Published: February 2024

This chapter explores the emergence of the Dutch paper industry in the phase of Dutch capitalism starting from 1580. Swiftly earning acclaim as the most reputable paper industry in Europe and beyond, the chapter elucidates the distinctions between the primary paper production regions during this period, namely the Zaanstreek and the Veluwe. Offering an intricate analysis of the contrasting organization of employers and laborers, diverse politico-economic conditions and industrial integration, as well as variations in resource availability and pre-industrial innovation in each region, the chapter eloquently highlights the transitional and non-linear character of the succession from feudalism to capitalism during that era.
Inclusive semileptonic $$ b\to c\ell \overline{\nu} $$ decays to order $$ 1/{m}_b^5 $$
Authors: Mannel Thomas , Milutin Ilija S. , Vos K. Keri
Published: February 2024

Abstract

Inclusive semileptonic

$$ B\to {X}_c\ell \overline{\nu} $$

B
→

X
c

ℓ

ν
¯

decays can be described in the Heavy Quark Expansion (HQE) and allow for a precision determination of the CKM element |V

cb
|. We calculate the terms of

$$ 1/{m}_b^5 $$

1
/

m
b
5

and derive a “trace formula” which allows for the computation of the decay rate and kinematic moments of the spectrum up to this order in the HQE. We focus specifically on the reparametrization invariant (RPI) dilepton invariant mass q
2 moments of the spectrum, which depend on a reduced set of HQE parameters. At this order, “intrinsic charm” (IC) contributions proportional to

$$ 1/\left({m}_b^3{m}_c^2\right) $$

1
/

m
b
3

m
c
2

enter, which are numerically expected to be sizeable. Using the “lowest-lying state saturation ansatz” (LLSA), we estimate the size of these contributions. Within this approximation, we observe a partial cancellation between the IC and the “genuine”

$$ 1/{m}_b^5 $$

1
/

m
b
5

contributions, resulting in a small overall contribution.
Parametric generation of optimal structures through discrete exponential functions: unveiling connections between structural optimality and discrete isothermicity
Authors: Hayashi Kazuki , Jikumaru Yoshiki , Yokosuka Yohei , Hayakawa Kentaro , Kajiwara Kenji
Published: February 2024

This study discusses an equilibrium state of structures endowed with integrability and relates the structural optimality for Michell’s classic problem and the isothermicity in discrete differential geometry. This discussion leads to a new approach for the parametric generation of quasi-optimal layouts of bar members. The layout of bar members is determined by taking the diagonals of a quadrilateral mesh constructed from a discrete exponential function. The configuration of the planar layout can be changed by adjusting the parameters of a discrete exponential function. In addition, the inverse stereographic projection allows for obtaining spherical shapes from the planar layouts, and the Möbius transformations enable the generation of eccentric near-optimal shapes. It is also demonstrated that the structural layouts generated in this study are the exact optimal or near-optimal solution to Michell’s optimization problem.
Optimize or satisfice in engineering design?
Authors: Guo Lin , Allen Janet K. , Mistree Farrokh
Published: February 2024

In this paper, we address the issue of whether to optimize or satisfice in model-based engineering design. When dealing with operations research problems in the context of engineering design, one may encounter (i) nonlinear, nonconvex objectives and constraints, (ii) objectives with different units, and (iii) computational models that are abstractions of reality and fidelity, Seeking a single-point optimal solution that meets the necessary and sufficient Karush–Kuhn–Tucker (KKT) conditions makes it impossible to obtain a solution that satisfies all the targeted goals. Instead, a method to identify satisficing solutions that satisfies necessary KKT condition but not the sufficient condition is proposed. These solutions are relatively robust, easy to acquire, and often good enough. In this paper, we demonstrate the combined use of the compromise Decision Support Problems and the adaptive linear programming algorithm, as proposed by Mistree and co-authors. This method is appropriate in formulating design problems and obtaining solutions that satisfy only the necessary KKT condition. Further, the use of the proposed method circumvents complications associated with the use of gradient-based optimization algorithms typically used to solve optimization problems. We discuss the efficacy of our proposed method using four test problems to illustrate how the satisficing strategy outperforms the optimizing strategy in model-based engineering design.
Analyzing microbial community and volatile compound profiles in the fermentation of cigar tobacco leaves
Authors: Zhang Mingzhu , Guo Dongfeng , Wang Haiqing , Wu Guanglong , Shi Yaqi , Zhou Jinlong , Zhao Eryong , Zheng Tianfei , Li Xingjiang
Published: February 2024

Variations in industrial fermentation techniques have a significant impact on the fermentation of cigar tobacco leaves (CTLs), consequently influencing the aromatic attributes of the resulting cigars. The entire fermentation process of CTLs can be categorized into three distinct phases: phase 1 (CTLs prior to moisture regain), phase 2 (CTLs post-moisture regain and pile fermentation), and phase 3 (CTLs after fermentation and drying). These phases were determined based on the dynamic changes in microbial community diversity. During phase 2, there was a rapid increase in moisture and total acid content, which facilitated the proliferation of Aerococcus, a bacterial genus capable of utilizing reducing sugars, malic acid, and citric acid present in tobacco leaves. In contrast, fungal microorganisms exhibited a relatively stable response to changes in moisture and total acid, with Aspergillus, Alternaria, and Cladosporium being the dominant fungal groups throughout the fermentation stages. Bacterial genera were found to be more closely associated with variations in volatile compounds during fermentation compared to fungal microorganisms. This association ultimately resulted in higher levels of aroma components in CTLs, thereby improving the overall quality of the cigars. These findings reinforce the significance of industrial fermentation in shaping CTL quality and provide valuable insights for future efforts in the artificial regulation of secondary fermentation in CTLs.

Key points

• Industrial fermentation processes impact CTLs microbial communities.

• Moisture and total acid content influence microbial community succession in fermentation.

• Bacterial microorganisms strongly influence CTLs’ aldehyde and ketone flavors over fungi.
Secretory IgA reduced the ergosterol contents of Candida albicans to repress its hyphal growth and virulence
Authors: Wang Jiannan , Shen Jiawei , Chen Ding , Liao Binyou , Chen Xi , Zong Yawen , Wei Yu , Shi Yangyang , Liu Yaqi , Gou Lichen , Zhou Xuedong , Cheng Lei , Ren Biao
Published: February 2024

Candida albicans, one of the most prevalent conditional pathogenic fungi, can cause local superficial infections and lethal systemic infections, especially in the immunocompromised population. Secretory immunoglobulin A (sIgA) is an important immune protein regulating the pathogenicity of C. albicans. However, the actions and mechanisms that sIgA exerts directly against C. albicans are still unclear. Here, we investigated that sIgA directs against C. albicans hyphal growth and virulence to oral epithelial cells. Our results indicated that sIgA significantly inhibited C. albicans hyphal growth, adhesion, and damage to oral epithelial cells compared with IgG. According to the transcriptome and RT-PCR analysis, sIgA significantly affected the ergosterol biosynthesis pathway. Furthermore, sIgA significantly reduced the ergosterol levels, while the addition of exogenous ergosterol restored C. albicans hyphal growth and adhesion to oral epithelial cells, indicating that sIgA suppressed the growth of hyphae and the pathogenicity of C. albicans by reducing its ergosterol levels. By employing the key genes mutants (erg11Δ/Δ, erg3Δ/Δ, and erg3Δ/Δ erg11Δ/Δ) from the ergosterol pathway, sIgA lost the hyphal inhibition on these mutants, while sIgA also reduced the inhibitory effects of erg11Δ/Δ and erg3Δ/Δ and lost the inhibition of erg3Δ/Δ erg11Δ/Δ on the adhesion to oral epithelial cells, further proving the hyphal repression of sIgA through the ergosterol pathway. We demonstrated for the first time that sIgA inhibited C. albicans hyphal development and virulence by affecting ergosterol biosynthesis and suggest that ergosterol is a crucial regulator of C. albicans-host cell interactions.

Key points

• sIgA repressed C. albicans hyphal growth

• sIgA inhibited C. albicans virulence to host cells

• sIgA affected C. albicans hyphae and virulence by reducing its ergosterol levels
The non-mevalonate pathway requires a delicate balance of intermediates to maximize terpene production
Authors: Raghavan Indu , Juman Rosheena , Wang Zhen Q.
Published: February 2024

Terpenes are valuable industrial chemicals whose demands are increasingly being met by bioengineering microbes such as E. coli. Although the bioengineering efforts commonly involve installing the mevalonate (MVA) pathway in E. coli for terpene production, the less studied methylerythritol phosphate (MEP) pathway is a more attractive target due to its higher energy efficiency and theoretical yield, despite its tight regulation. In this study, we integrated an additional copy of the entire MEP pathway into the E. coli genome for stable, marker-free terpene production. The genomically integrated strain produced more monoterpene geraniol than a plasmid-based system. The pathway genes’ transcription was modulated using different promoters to produce geraniol as the reporter of the pathway flux. Pathway genes, including dxs, idi, and ispDF, expressed from a medium-strength promoter, led to the highest geraniol production. Quantifying the MEP pathway intermediates revealed that the highest geraniol producers had high levels of isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP), but moderate levels of the pathway intermediates upstream of these two building blocks. A principal component analysis demonstrated that 1-deoxy-D-xylulose 5-phosphate (DXP), the product of the first enzyme of the pathway, was critical for determining the geraniol titer, whereas MEP, the product of DXP reductoisomerase (Dxr or IspC), was the least essential. This work shows that an intricate balance of the MEP pathway intermediates determines the terpene yield in engineered E. coli. The genetically stable and intermediate-balanced strains created in this study will serve as a chassis for producing various terpenes.

Key points

• Genome-integrated MEP pathway afforded higher strain stability

• Genome-integrated MEP pathway produced more terpene than the plasmid-based system

• High monoterpene production requires a fine balance of MEP pathway intermediates
Predicting and optimizing marketing performance in dynamic markets
Authors: Guhl Daniel , Paetz Friederike , Wagner Udo , Wedel Michel
Published: February 2024

Our world is turbulent: ecological, social, political, technological, economic, and competitive business environments change constantly. Consumers have changing preferences, learn, build trust in brands, adopt new products, and are persuaded by advertising. Firms innovate and engage in and respond to competition. Exogenous events, such as changes in economic conditions and regulations, as well as human crises, also cause major shifts in markets. This special issue focuses on novel Marketing data and modern methodologies from different fields (e.g., Operations Research (OR), Statistics, Econometrics, and Computer Science), which help firms understand, utilize, and respond to market dynamics more efficiently. Here we propose a framework comprising analytical methods and data for dynamic markets that is useful for structuring research in this domain. Next, we summarize the history of the Marketing/OR interface. We highlight studies at the Marketing/OR interface from the last decade focusing specifically on dynamic markets and use our proposed framework to identify trends and gaps in the extant literature. After that, we present and summarize the papers of the current special issue and their contributions to the field against the backdrop of our framework and the trends in the literature. Finally, we conclude and discuss which future Marketing/OR research could tackle important issues in dynamic markets.
Die Geschichte des implantierbaren Kardioverter-Defibrillators in Deutschland
Authors: Block Michael , Klein Helmut U.
Published: February 2024

Der implantierbare Kardioverter-Defibrillator (ICD) war ein Durchbruch in der Prävention des plötzlichen Herztodes. Nach jahrelanger technischer Entwicklung durch Michel Mirowski erfolgten trotz vieler Widerstände in den USA 1980 erste Implantationen. Es konnte gezeigt werden, dass Kammerflimmern zuverlässig durch den ICD automatisch erkannt und defibrilliert wurde. Knapp 4 Jahre nach den USA begannen mehrere Zentren, in Deutschland ICDs zu implantieren. Bald wurden außerhalb der USA in Deutschland die meisten Patienten versorgt. Die absolute Zahl der Implantationen war weiterhin klein, solange nur Implantationen mittels Thorakotomie und epikardialen Defibrillationselektroden möglich waren. Anfang der 1990er Jahre konnte ein ICD pektoral, wie ein Schrittmacher, in Kombination mit einer transvenösen Defibrillationselektrode implantiert werden. Die Implantationszahlen stiegen sprunghaft an. Die klinische Forschung in Deutschland begleitete die technischen Fortentwicklungen und hier erfolgten viele First-in-human-Studien. In den USA und Deutschland wurden 1991 erste Leitlinien zur Indikation herausgegeben. Randomisierte Studien zur Mortalität, zumeist unter amerikanischer Leitung mit deutscher Beteiligung, aber auch unter deutscher Leitung (CASH, CAT, DINAMIT, IRIS), wurden zwischen 1996 und 2009 publiziert. Die Ergebnisse dieser lang zurückliegenden Studien wurden 2016 in Frage gestellt, als die DANISH-Studie keine signifikante Verbesserung der Mortalität ergab. Die Implantationszahlen sind seitdem rückläufig. Derzeit wird daran geforscht, genau die Patienten zu versorgen, die trotz optimaler Therapie vor dem plötzlichen Herztod geschützt werden müssen. Risikoscores unter Einbeziehung myokardialer Narben in der Magnetresonanztomographie (MRT) und genetischer Information sollen hierzu beitragen.
White matter brain age as a biomarker of cerebrovascular burden in the ageing brain
Authors: Du Jing , Pan Yuangang , Jiang Jiyang , Lam Ben C. P. , Thalamuthu Anbupalam , Chen Rory , Tsang Ivor W. , Sachdev Perminder S. , Wen Wei
Published: February 2024

As the brain ages, it almost invariably accumulates vascular pathology, which differentially affects the cerebral white matter. A rich body of research has investigated the link between vascular risk factors and the brain. One of the less studied questions is that among various modifiable vascular risk factors, which is the most debilitating one for white matter health? A white matter specific brain age was developed to evaluate the overall white matter health from diffusion weighted imaging, using a three-dimensional convolutional neural network deep learning model in both cross-sectional UK biobank participants (n = 37,327) and a longitudinal subset (n = 1409). White matter brain age gap (WMBAG) was the difference between the white matter age and the chronological age. Participants with one, two, and three or more vascular risk factors, compared to those without any, showed an elevated WMBAG of 0.54, 1.23, and 1.94 years, respectively. Diabetes was most strongly associated with an increased WMBAG (1.39 years, p < 0.001) among all risk factors followed by hypertension (0.87 years, p < 0.001) and smoking (0.69 years, p < 0.001). Baseline WMBAG was associated significantly with processing speed, executive and global cognition. Significant associations of diabetes and hypertension with poor processing speed and executive function were found to be mediated through the WMBAG. White matter specific brain age can be successfully targeted for the examination of the most relevant risk factors and cognition, and for tracking an individual’s cerebrovascular ageing process. It also provides clinical basis for the better management of specific risk factors.