bluuebunny/crossref_metadata_2025 huggingface dataset:
Infinite versus finite 1D-dielectric gratings supporting SP-BIC modes for sensing applications
Authors: Djemaiai Lylia , Hamidi Mahdi , Mezeghrane Abdelaziz , Belkhir Abderrahmane , Baida Fadi Issam
Published: January 2024

In this paper, we investigate the existence of a special so-called Symmetry-Protected Bound state In the Continuum (SP-BIC) mode in a typical infinite and finite 1D-periodic TiO2-based dielectric structure. Using Finite-Difference Time-Domain (FDTD), Fourier-Modal Method (FMM) and N-order FDTD simulations, a complete optical characterization of the structure is performed. In comparison with the classical Guided Mode Resonance (GMR), the existence and the excitation efficiency of this particular mode are studied with respect to the illumination conditions of the structure and the number of periods when the structure is finite. Our results are an additional contribution to designing efficient resonators for sensing applications. It is shown that for a finite and then more realistic structure, the quality factor is directly related to the number of periods N. It reaches the same value as for the infinite case when the number of periods is N = 200. A high sensitivity, comparable to the infinite case, is also obtained from N = 50.
Image encryption algorithm based on improved iterative chaotic map with infinite collapses and Gray code
Authors: Wang Quanyv , Zhang Xiaoqiang , Zhao Xiaohu
Published: January 2024

The quick advancement of multimedia technology has led to the widespread utilization of digital images across various industries. Meanwhile, image security has become an urgent issue in need of resolution. To guarantee image security as well fulfill the requirements of real-time image cryptosystems, a novel image encryption algorithm is proposed based on the designed improved iterative chaotic map with infinite collapses (ICMIC), Gray code and semi-pixel level permutation and diffusion. Firstly, two chaotic sequences are produced using the improved ICMIC and then they are used to perform scrambling and diffusion operations. Secondly, the plain image is encoded using Gray code and then we convert each Gray code into two semi-pixels. Thirdly, the designed semi-pixel level permutation is used to scramble the semi-pixel vector. Finally, the scrambled semi-pixel vector is diffused using the designed dynamic semi-pixel level diffusion. The performance analyses illustrate that the proposed algorithm possesses robust security and high efficiency, making it ideally suited for application in real-time image cryptosystems.
Cosmic background neutrinos deflected by gravity: DEMNUni simulation analysis
Authors: Hernández-Molinero Beatriz , Carbone Carmelita , Jimenez Raul , Garay Carlos Peña
Published: January 2024

The local supercluster acts as a gravity deflection source for cosmic background
neutrinos. This deflection by gravity changes the neutrino helicity and therefore has important
consequences for ground based tritium capture experiments aimed at determining if the neutrino is
Dirac or Majorana. Here we explore the deflection effect of the local supercluster using two
simulations from the DEMNUni suite characterised by very different mass resolutions, as they are
both filled with 20483 dark matter particles (and an equal number of massive neutrino
particles) but have comoving volumes of (2 h
-1Gpc)3 and (500 h
-1Mpc)3, respectively. We reaffirm our previous results and show that the lightest
neutrinos are ultra-relativistic enough to suffer little deflection by gravity and at the same
time not relativistic enough to achieve the same capture rate for Dirac and Majorana cases. This
means that the capture rate in Ptolemy-like experiments will be sensitive to the neutrino nature
and that gravity deflection enlarges the difference between Majorana and Dirac rates. Moreover,
using the relation between mass and momentum of the neutrinos frozen Fermi-Dirac distribution, but
taking into consideration gravity corrections, we are able to calculate the deflection angle for
different neutrino masses from the same set of neutrinos obtained from the simulation. Doing so,
we provide a formula to compute the deflection angle for any neutrino mass, such that when
cosmology detects an absolute neutrino mass, precise predictions can be made for tritium
ground-based detectors on Earth aimed to determine neutrinos nature.
The fate of a quantum-corrected collapsing star in General Relativity
Authors: Gupta Choudhury Shibendu , Chakrabarti Soumya
Published: January 2024

We incorporate some corrections inspired by loop quantum gravity into the concept of gravitational collapse and propose a complete model of the dynamic process. The model carries the essence of a mass-independent upper bound on the curvature scalars, originally found as a crucial feature of black holes in loop quantum gravity. The quantum-inspired interior is immersed in a geometry filled with null radiation, and they are matched at a distinct boundary hypersurface. The ultimate fate of the process depends on the inhomogeneities of the metric tensor coefficients. We find a critical parameter λ embedded in the inhomogeneity of the conformal factor of the interior metric. Examples with λ< 0 enforce an eventual collapse to singularity, and λ> 0 cases produce a non-singular collapse resulting in a loop-quantum-corrected Schwarzschild geometry modulo a conformal factor. Interestingly, for λ< 0 as well, there exist situations where the quantum effects are able to cause a bounce but fall short of preventing the ultimate formation of a singularity. The trapped surface formation condition is studied for the λ<0 case to infer about the visibility of the final singularity. Interestingly, we find a possibility of the formation of three horizons during the course of the collapse. Eventually, all of them merge into a single horizon, which envelopes the final singularity. For the non-singular case, there is a possibility that the sphere can evolve into a wormhole throat whose radius is found to be inversely proportional to the critical parameter λ. Depending on the nature of evolution and the shell regions, the collapsing shells violate some standard energy conditions, which can be associated with quantum-inspired corrections.
Bimetallic solid solution MAX phase Ti2NbAlC2 as saturable absorber for passively Q-switched Er3+-doped fiber laser
Authors: Zhao Bin , Zhang Hong-Ping , Ma Rong-Ze , Farrell Gerald , Li Zhen-Rui , Wang Peng-Fei
Published: January 2024

In this paper, we demonstrated a stable Q-switched fiber laser operation with a central wavelength of 1531.43 nm using a bimetallic solid solution MAX phase Ti2NbAlC2 saturable absorber. The minimum pulse duration of 3.67 μs and the maximum repetition rate of 32.56 kHz were acquired at the pump power of 300 mW. Furthermore, the Q-switched pulse has a maximum output power of 1.08 mW and a maximum pulse energy of 33.14 nJ. Our results indicate that the Ti2NbAlC2 is a promising saturable absorber material. The bimetallic solid solution MAX phase materials may be developed as novel nonlinear photonic devices with outstanding performance.
Individual dynamics and local heterogeneity provide a microscopic view of the epidemic spreading
Authors: Zhu 朱 Youyuan 友源 , Shen 沈 Ruizhe 瑞哲 , Dong 董 Hao 昊 , Wang 王 Wei 炜
Published: January 2024

The COVID-19 pandemic has caused severe global disasters, highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures. While the widely used deterministic compartmental models have qualitatively presented continuous “analytical” insight and captured some transmission features, their treatment usually lacks spatiotemporal variation. Here, we propose a stochastic individual dynamical (SID) model to mimic the random and heterogeneous nature of epidemic propagation. The SID model provides a unifying framework for representing the spatiotemporal variations of epidemic development by tracking the movements of each individual. Using this model, we reproduce the infection curves for COVID-19 cases in different areas globally and find the local dynamics and heterogeneity at the individual level that affect the disease outbreak. The macroscopic trend of virus spreading is clearly illustrated from the microscopic perspective, enabling a quantitative assessment of different interventions. Seemingly, this model is also applicable to studying stochastic processes at the “meter scale”, e.g., human society’s collective dynamics.
Exploration of the coupled lattice Boltzmann model based on a multiphase field model: A study of the solid–liquid–gas interaction mechanism in the solidification process
Authors: Zhu 朱 Chang-Sheng 昶胜 , Wang 王 Li-Jun 利军 , Gao 高 Zi-Hao 梓豪 , Liu 刘 Shuo 硕 , Li 李 Guang-Zhao 广召
Published: January 2024

A multiphase field model coupled with a lattice Boltzmann (PF-LBM) model is proposed to simulate the distribution mechanism of bubbles and solutes at the solid-liquid interface, the interaction between dendrites and bubbles, and the effects of different temperatures, anisotropic strengths and tilting angles on the solidified organization of the SCN-0.24wt.% butanedinitrile alloy during the solidification process. The model adopts a multiphase field model to simulate the growth of dendrites, calculates the growth motions of dendrites based on the interfacial solute equilibrium; and adopts a lattice Boltzmann model (LBM) based on the Shan–Chen multiphase flow to simulate the growth and motions of bubbles in the liquid phase, which includes the interaction between solid–liquid–gas phases. The simulation results show that during the directional growth of columnar dendrites, bubbles first precipitate out slowly at the very bottom of the dendrites, and then rise up due to the different solid–liquid densities and pressure differences. The bubbles will interact with the dendrite in the process of flow migration, such as extrusion, overflow, fusion and disappearance. In the case of wide gaps in the dendrite channels, bubbles will fuse to form larger irregular bubbles, and in the case of dense channels, bubbles will deform due to the extrusion of dendrites. In the simulated region, as the dendrites converge and diverge, the bubbles precipitate out of the dendrites by compression and diffusion, which also causes physical phenomena such as fusion and spillage of the bubbles. These results reveal the physical mechanisms of bubble nucleation, growth and kinematic evolution during solidification and interaction with dendrite growth.
Period–Luminosity Relationship for δ Scuti Stars Revisited
Authors: Poro Atila , Jafarzadeh S. Javad , Harzandjadidi Roghaye , Madani Mohammad , Bozorgzadeh Elnaz , Jahangiri Esfandiar , Sarostad Ahmad , Alizadehsabegh Ailar , Hadizadeh Maryam , EsmaeiliVakilabadi Mohammad
Published: January 2024

The Gaia DR3 parallax approach was used to estimate the absolute parameters of 2375 δ Scuti stars from the ASAS catalog. The selected stars have a variety of observational characteristics, with a higher than 80% probability of being δ Scuti stars. We have displayed all the stars in the Hertzsprung–Russell diagram along with the δ Scuti instability strip, the Zero Age Main Sequence and the Terminal Age Main Sequence. Then, we determined which fundamental and overtone modes each star belongs to using pulsation constant (Q) calculations. In addition, we evaluated the parameters in the Q calculation equation using three machine learning methods, which showed that surface gravity and temperature have the greatest effect on its calculation. The Period–Luminosity (P-L) relationship of the δ Scuti stars was also revisited. Eventually, using least squares linear regression, we made four linear fits for fundamental and overtone modes and updated their relationships.
Graphene-based electrochemical system for tritium enrichment
Authors: Zabolockis R.J. , Sondars M. , Vaivars G. , Reinholds I. , Gostilo V. , Malgin V. , Kizilov A. , Lescinskis A. , Felsharuk A. , Avotina L. , Teimane A.S. , Sprugis E. , Pajuste E.
Published: January 2024

In this study, a tritium enrichment system in the water phase has been developed based on the combination of a proton exchange membrane (PEM) electrolysis cell and a fuel cell. As the PEM, NafionTM and laboratory-synthesized sulfonated poly(ether ether ketone) membranes modified with an additional graphene layer in order to enhance the tritium separation factor were used. Both differences in the kinetics of the hydrogen evolution reaction and transport through the graphene layer of different isotopes are the driving factors expected to affect the separation of hydrogen isotopes. The separation factor was measured both during the electrolysis and fuel cell stage using different membranes. The facilitating effect of the graphene on the separation efficiency was determined during the study. The separation factor obtained by the proposed method was evidently higher than that obtained by other conventional methods.
Solidification of aluminium alloys in different conditions
Authors: Petrova Anna , Yaneva Svetlana , Stoichev Nikolay
Published: January 2024

The development of modern nanotechnology has influenced the principles, design and characteristics of machines and parts. This applies mostly to materials that are used in the space industry. The first aspect concerns the technologies of synthesis, and the second - the qualities and applications of the materials.

To date, a limited number of scientific publications describing the preparation and production of materials in space conditions have been published. This article describes the equipment used during the second Russian-Bulgarian flight. In 1988, in space, on the MIR orbital station, 3 experiments related to materials science were conducted by Bulgarian researchers. One of the experiments is “Structure” led by N. Stoichev (BAS). A multifunctional apparatus “Kristalhizator CSK-1” manufactured in Czechoslovakia was used.
Improving Performance of Impact Point Determination Algorithms of Gamma Interaction in a Monolithic Scintillator Using ML and Numerical Methods
Authors: Ivanov Svetoslav , Ivanov Simeon , Lalkovski Stefan
Published: January 2024

Two algorithms for classification of the number of interaction points of gamma-ray in a Compton camera with scintillator crystal are developed, taking into account the limited processing power of the edge electronics in the space environment. One of the algorithms is relaying on a machine learning image classification convolution network, and the other is a numerical method, searching for multiple maxima peaks in the light intensity over the detector plane. Preliminary results of the accuracy of the two approaches are provided and discussed.
From biomimicry to robotic co-creation: rethinking the boundaries between nature and technology
Authors: Tamborini Marco
Published: January 2024

This paper is an invitation to an interdisciplinary dialogue on new possibilities for integrating robotics, design, and nature. I ask: how can new cross-movements between bio-inspired science and design be fostered? How might we envision the future possible intersection between technology and nature? First, I recall key aspects of classical bioinspired engineering and highlight the role of nature in the emergence of technology. Second, I introduce a new approach to bioinspired engineering. In this approach, robots play an active role in design and construction, learning from material properties to form new shapes and thus reshaping design paradigms. The distinctive elements of this approach depart from classical nature-inspired engineering and foster a symbiotic relationship between technology and nature. I conclude by reflecting on the intersections of nature, technology, and design, and envisioning new avenues for interdisciplinary dialogue that foster collaboration and innovation among diverse bio-inspired disciplines.
Impact of propagation losses on photon-pair generation in silicon
Authors: Sharma Shivani , Ghosh Joyee , Venkataraman Vivek
Published: January 2024

We present a semi-classical numerical model to estimate the impact of linear scattering loss and nonlinear absorption losses on the biphoton flux and their quantum correlations generated via spontaneous four-wave mixing in silicon nanowaveguides. The counter-intuitive observed enhancement of pair correlations with increasing loss is attributed to the dominant effect of reduced accidental counts from multiphoton generation, with a corresponding trade-off for the source brightness. Silicon nanowaveguides are shown to be capable of generating highly correlated paired photons with coincidental-to-accidental ratio as high as ∼3400 and spectral brightness

2.8
×

10

4

 pairs s−1 GHz−1 mW−1, even in the presence of linear propagation loss of 1 dB cm−1 and nonlinear losses (two-photon absorption and free-carrier absorption), over a length of 1 cm with an input pump power of 10 mW. Loss and the corresponding Langevin noise are modeled using distributed beam splitters along the waveguide length to encapsulate the phenomenological coupling to the background reservoir (vacuum fluctuations). The proposed numerical model is more general compared to previous analytical models, particularly for including dispersion and wavelength-dependent losses, and more accurate for noise estimation in the high-photon-flux regime such as optical parametric amplifiers and squeezed state generation.
Control of the valley polarization of monolayer WSe2 by Dexter-like coupling
Authors: Jasiński Jakub , Thompson Joshua J P , Palai Swaroop , Śmiertka Maciej , Dyksik Mateusz , Taniguchi Takashi , Watanabe Kenji , Baranowski Michał , Maude Duncan K , Surrente Alessandro , Malic Ermin , Płochocka Paulina
Published: January 2024

Intervalley scattering mechanisms strongly affect the dynamics of excitonic complexes in transition metal dichalcogenide monolayers. Here, we investigate the excitation energy dependence of the valley polarization of excitons in a WSe2 monolayer. We observe that the valley polarization drastically decreases when the excitation is resonant with the B

1
s

resonance. This behavior can be explained by a Dexter-like coupling in the momentum space between exciton states residing in opposite valleys but with the same spin configuration. This induces a net transfer of the exciton population from the optically driven valley towards the opposite, undriven valley. We observe the long-term fingerprints of this population transfer as a vanishing valley polarization for the neutral exciton, and a negative valley polarization for biexcitonic complexes, in qualitative agreement with theoretical predictions based on a fully microscopic many-particle approach. This, together with a decrease of the PL energy when the excitation is resonant with the B

1
s

state, points to the prominent role of the Dexter-like coupling in the exciton dynamics of atomically thin semiconductors.
Investigation on the effects of changing automotive vehicles leaf springs from steel to hybrid polymer composite leaf springs
Authors: P Vijayalakshmi , K Pazhanivel , P Praveen Raj , K Muruganantham
Published: January 2024

Weight reduction is a critical factor in the vehicles and numerous researchers worked on better materials and design optimization to achieve that goal. This paper is focused to design a natural fibre reinforced hybrid polymer composite mono leaf parabolic spring to replace the existing steel multi-leaf semi-elliptical spring in an attempt of reducing the unsprung mass and to investigate its characteristics. The spring so designed is analyzed for its deflection and stiffness, by Virtual work method, whose complex integral was solved numerically by Gauss Quadrature. Along with this, SolidWorks was used to construct a model and ANSYS tests were used to compute the deflection, analyze the stress pattern and verify that the fail proof condition is met. Subsequently, three prototypes of the springs were fabricated by hand lay-up method. These springs were subjected to a static load test which results in deflection values similar to that of laminated steel springs with an appreciable 83 percent weight reduction. Modal Analysis conducted ensures that the fundamental frequencies of different modes are conveniently away from values of human discomfort and also from the nominal driving engine speed of 2000 rpm. The responses to harmonic disturbances which were studied experimentally, analytically and by ANSYS which indicates that vibration amplitudes due to average road undulations are under control, limiting the amplitude within 12 mm. The newly designed spring shall be recommended as a potential replacement, which can further be augmented by future works to be carried out on pot holes and studying the force transmitted on to the vehicle.
Imperfect Information About Consumer Rights: Implications for Efficiency and Distribution
Authors: Baumann Florian , Friehe Tim , Wenzel Tobias
Published: January 2024

This paper shows that the provision of consumer rights can induce unintended distributional effects and may, under specific circumstances, even decrease welfare when some consumers are unaware of these rights. We find that consumers who are uninformed about a mandated warranty may demand excessively safe products when the share of informed consumers is high. In other circumstances, uninformed consumers buy the efficient or an inefficiently unsafe products like informed consumers, but the former cross-subsidize the latter via firms’ pricing. Concerning the salient policy option of improving information about consumer rights, we find that increasing the share of informed consumers may raise the risk of inefficiency.
A Case for Pay Secrecy
Authors: Blumkin Tomer , Lagziel David , Margalioth Yoram
Published: January 2024

In this paper, we study a labor market setup in which workers exhibit relative remuneration concerns with respect to their peers. We first characterize the optimal labor contract offered by the firm and provide necessary and sufficient conditions for the desirability of incorporating pay-secrecy clauses in such a contract. We then demonstrate that, in contrast to conventional wisdom viewing wage-secrecy arrangements as detrimental for workers, the latter may, in fact, gain from the lack of pay transparency.
Embedding-based alignment: combining protein language models with dynamic programming alignment to detect structural similarities in the twilight-zone
Authors: Pantolini Lorenzo , Studer Gabriel , Pereira Joana , Durairaj Janani , Tauriello Gerardo , Schwede Torsten
Published: January 2024

Motivation

Language models are routinely used for text classification and generative tasks. Recently, the same architectures were applied to protein sequences, unlocking powerful new approaches in the bioinformatics field. Protein language models (pLMs) generate high-dimensional embeddings on a per-residue level and encode a “semantic meaning” of each individual amino acid in the context of the full protein sequence. These representations have been used as a starting point for downstream learning tasks and, more recently, for identifying distant homologous relationships between proteins.

Results

In this work, we introduce a new method that generates embedding-based protein sequence alignments (EBA) and show how these capture structural similarities even in the twilight zone, outperforming both classical methods as well as other approaches based on pLMs. The method shows excellent accuracy despite the absence of training and parameter optimization. We demonstrate that the combination of pLMs with alignment methods is a valuable approach for the detection of relationships between proteins in the twilight-zone.

Availability and implementation

The code to run EBA and reproduce the analysis described in this article is available at: https://git.scicore.unibas.ch/schwede/EBA and https://git.scicore.unibas.ch/schwede/eba_benchmark.
Who am I?
Authors: Routledge Brian
Published: January 2024

Winner of the Brain Essay Competition 2023, Brian Routledge considers where gene repair technology might take us, in this fictional account written from the perspective of a parent whose child has a severe neurodevelopmental condition.
Transcriptomics reveals CSF cellular composition in multiple sclerosis but detects no viral RNA
Authors: Schwab Nicholas
Published: January 2024

This scientific commentary refers to ‘Expression profiling of cerebrospinal fluid identifies dysregulated antiviral mechanisms in multiple sclerosis’ by Ban et al. (https://doi.org/10.1093/brain/awad404).
Extracellular Vesicles as Liquid Biopsy Biomarkers across the Cancer Journey: From Early Detection to Recurrence
Authors: Rayamajhi Sagar , Sipes Jared , Tetlow Ashley L , Saha Souvik , Bansal Ajay , Godwin Andrew K
Published: January 2024

Background

Cancer is a dynamic process and thus requires highly informative and reliable biomarkers to help guide patient care. Liquid-based biopsies have emerged as a clinical tool for tracking cancer dynamics. Extracellular vesicles (EVs), lipid bilayer delimited particles secreted by cells, are a new class of liquid-based biomarkers. EVs are rich in selectively sorted biomolecule cargos, which provide a spatiotemporal fingerprint of the cell of origin, including cancer cells.

Content

This review summarizes the performance characteristics of EV-based biomarkers at different stages of cancer progression, from early malignancy to recurrence, while emphasizing their potential as diagnostic, prognostic, and screening biomarkers. We discuss the characteristics of effective biomarkers, consider challenges associated with the EV biomarker field, and report guidelines based on the biomarker discovery pipeline.

Basic science and clinical trial studies have shown the potential of EVs as precision-based biomarkers for tracking cancer status, with promising applications for diagnosing disease, predicting response to therapy, and tracking disease burden. The multi-analyte cargos of EVs enhance the performance characteristics of biomarkers. Recent technological advances in ultrasensitive detection of EVs have shown promise with high specificity and sensitivity to differentiate early-cancer cases vs healthy individuals, potentially outperforming current gold-standard imaging-based cancer diagnosis. Ultimately, clinical translation will be dictated by how these new EV biomarker-based platforms perform in larger sample cohorts. Applying ultrasensitive, scalable, and reproducible EV detection platforms with better design considerations based upon the biomarker discovery pipeline should guide the field towards clinically useful liquid biopsy biomarkers.
Frequency and Prognostic Value of Circulating Tumor Cells in Cancer of Unknown Primary
Authors: Pouyiourou Maria , Bochtler Tilmann , Coith Cornelia , Wikman Harriet , Kraft Bianca , Hielscher Thomas , Stenzinger Albrecht , Riethdorf Sabine , Pantel Klaus , Krämer Alwin
Published: January 2024

BACKGROUND

Cancer of unknown primary (CUP) is defined as a primary metastatic malignancy, in which the primary tumor remains elusive in spite of a comprehensive diagnostic workup. The frequency and prognostic value of circulating tumor cells (CTCs), which are considered to be the source of metastasis, has not yet been systematically evaluated in CUP.

METHODS

A total of 110 patients with a confirmed diagnosis of CUP according to the European Society for Medical Oncology (ESMO) guidelines, who presented to our clinic between July 2021 and May 2023, provided blood samples for CTC quantification using CellSearch methodology. CTC counts were correlated with demographic, clinical, and molecular data generated by comprehensive genomic profiling of tumor tissue.

RESULTS

CTCs were detected in 26% of all patients at initial presentation to our department. The highest CTC frequency was observed among patients with unfavorable CUP (35.5%), while patients with single-site/oligometastatic CUP harbored the lowest CTC frequency (11.4%). No statistically significant association between CTC positivity and the number of affected organs (P = 0.478) or disease burden (P = 0.120) was found. High CTC levels (≥5 CTCs/7.5 mL; 12/95 analyzed patients) predicted for adverse overall survival compared to negative or low CTC counts (6-months overall survival rate 90% vs 32%, log-rank P < 0.001; HR 5.43; 95% CI 2.23–13.2). CTC dynamics were also prognostic for overall survival by landmark analysis (log-rank P < 0.001, HR 10.2, 95% CI 1.95–52.9).

CONCLUSIONS

CTC frequency is a strong, independent predictor of survival in patients with CUP. CTC quantification provides a useful prognostic tool in the management of these patients.
Cyclophilin A is a ligand for RAGE in thrombo-inflammation
Authors: Seizer Peter , von Ungern-Sternberg Saskia N I , Haug Verena , Dicenta Valerie , Rosa Annabelle , Butt Elke , Nöthel Moritz , Rohlfing Anne-Katrin , Sigle Manuel , Nawroth Peter P , Nussbaum Claudia , Sperandio Markus , Kusch Charly , Meub Mara , Sauer Markus , Münzer Patrick , Bieber Kristin , Stanger Anna , Mack Andreas F , Huber René , Brand Korbinian , Lehners Moritz , Feil Robert , Poso Antti , Krutzke Konstantin , Schäffer Tilman E , Nieswandt Bernhard , Borst Oliver , May Andreas E , Zernecke Alma , Gawaz Meinrad , Heinzmann David
Published: January 2024

Aims

Cyclophilin A (CyPA) induces leucocyte recruitment and platelet activation upon release into the extracellular space. Extracellular CyPA therefore plays a critical role in immuno-inflammatory responses in tissue injury and thrombosis upon platelet activation. To date, CD147 (EMMPRIN) has been described as the primary receptor mediating extracellular effects of CyPA in platelets and leucocytes. The receptor for advanced glycation end products (RAGE) shares inflammatory and prothrombotic properties and has also been found to have similar ligands as CD147. In this study, we investigated the role of RAGE as a previously unknown interaction partner for CyPA.

Methods and results

Confocal imaging, proximity ligation, co-immunoprecipitation, and atomic force microscopy were performed and demonstrated an interaction of CyPA with RAGE on the cell surface. Static and dynamic cell adhesion and chemotaxis assays towards extracellular CyPA using human leucocytes and leucocytes from RAGE-deficient Ager−/− mice were conducted. Inhibition of RAGE abrogated CyPA-induced effects on leucocyte adhesion and chemotaxis in vitro. Accordingly, Ager−/− mice showed reduced leucocyte recruitment and endothelial adhesion towards CyPA in vivo. In wild-type mice, we observed a downregulation of RAGE on leucocytes when endogenous extracellular CyPA was reduced. We furthermore evaluated the role of RAGE for platelet activation and thrombus formation upon CyPA stimulation. CyPA-induced activation of platelets was found to be dependent on RAGE, as inhibition of RAGE, as well as platelets from Ager−/− mice showed a diminished activation and thrombus formation upon CyPA stimulation. CyPA-induced signalling through RAGE was found to involve central signalling pathways including the adaptor protein MyD88, intracellular Ca2+ signalling, and NF-κB activation.

Conclusion

We propose RAGE as a hitherto unknown receptor for CyPA mediating leucocyte as well as platelet activation. The CyPA–RAGE interaction thus represents a novel mechanism in thrombo-inflammation.
Diagnostic Accuracy of Intestinal Ultrasound in the Detection of Intra-Abdominal Complications in Crohn’s Disease: A Systematic Review and Meta-Analysis
Authors: Pruijt Maarten J , de Voogd Floris A E , Montazeri Nahid S M , van Etten-Jamaludin Faridi S , D’Haens Geert R , Gecse Krisztina B
Published: January 2024

Background

Crohn’s disease [CD] is frequently associated with the development of strictures and penetrating complications. Intestinal ultrasound [IUS] is a non-invasive imaging modality ideal for point-of-care assessment. In this systematic review and meta-analysis we provide a current overview on the diagnostic accuracy of IUS and its advanced modalities in the detection of intra-abdominal complications in CD compared to endoscopy, cross-sectional imaging, surgery, and pathology.

Method

We conducted a literature search for studies describing the diagnostic accuracy of IUS in adult patients with CD-related intra-abdominal complications. Quality of the included studies was assessed with the QUADAS-2 tool. Meta-analysis was performed for both conventional IUS [B-mode] and oral contrast IUS [SICUS].

Results

Of the 1498 studies we identified, 68 were included in this review and 23 studies [3863 patients] were used for the meta-analysis. Pooled sensitivities and specificities for strictures, inflammatory masses, and fistulas by B-mode IUS were 0.81 and 0.90, 0.87 [sensitivities] and 0.95, and 0.67 and 0.97 [specificities], respectively. Pooled overall log diagnostic odds ratios were 3.56, 3.97 and 3.84, respectively. Pooled sensitivity and specificity of SICUS were 0.94 and 0.95, 0.91 and 0.97 [sensitivities], and 0.90 and 0.94 [specificities], respectively. The pooled overall log diagnostic odds ratios of SICUS were 4.51, 5.46, and 4.80, respectively.

Conclusion

IUS is accurate for the diagnosis of intra-abdominal complications in CD. As a non-invasive, point-of-care modality, IUS is recommended as the first-line imaging tool if there is a suspicion of CD-related intra-abdominal complications.
Contact with general practice in patients with suspected chronic coronary syndrome before and after CT angiography compared with the general population
Authors: Nissen Louise , Søby Jacob Hartmann , de Thurah Annette , Prescott Eva , Prior Anders , Winther Simon , Bøttcher Morten
Published: January 2024

Background

Most patients undergoing coronary computed tomography angiography (CCTA) to diagnose coronary artery disease (CAD) are referred from general practitioners (GPs). The burden of contacts to GP in relation to investigation of suspected CAD is unknown.

Methods and results

All patients undergoing CCTA in Western Denmark from 2014 to 2022 were included. CCTA stenosis was defined as diameter stenosis of ≥50%. Patients with and without stenosis were matched, in each group, 1:5 to a reference population based on birth year, gender, and municipality using data from national registries. All GP visits were registered up to 5 years preceding and 1 year after the CTA and stratified by gender and age. Charlson comorbidity index (CCI) was calculated in all groups.

Of the 62 512 patients included, 12 886 had a stenosis, while 49 626 did not. Patients in both groups had a substantially higher GP visit frequency compared with reference populations. In the year of coronary CTA, the median GP contacts in patients with stenosis were 11 (6–17) vs. 6 (2–11) in the reference population (P < 0.001), and in patients without stenosis, the median GP contacts were 10 (6–17) vs. 5 (2–11) (P < 0.001). These findings were consistent across age and gender. CCI was higher among both patients with and without stenosis compared with reference groups.

Conclusion

In patients undergoing CCTA to diagnose CAD, a substantially increased frequency of contacts to GP was observed in the 5-year period prior to examination compared with the reference populations, regardless of the CCTA findings. Obtaining the CCTA result did not seem to substantially affect the GP visit frequency.
Post-mortem examination of fatal acute type A aortic dissection: what does it teach us?
Authors: Karadzha Anastasiia , Schaff Hartzell V , Frye Robert L , Bois Melanie C , Crestanello Juan A , Bagameri Gabor , Greason Kevin L , Shrestha Malakh L
Published: January 2024

OBJECTIVES

Acute type A aortic dissection (ATAAD) remains a highly life-threatening condition. This study investigates factors associated with fatal ATAAD prior to surgical treatment.

METHODS

We reviewed autopsy reports of ATAAD decedents who died before surgical intervention and underwent postmortem examination at our clinic from 1994 to 2022.

RESULTS

Among 94 eligible cases, 50 (53.2%) decedents had DeBakey type I dissection, and 44 (46.8%) had DeBakey type II dissection. Most were males, 63 (67%), and 72 (77%) had a history of hypertension. The median age was 70.5 years, and the type II group was a decade older than the type I group (P < 0.001). Decedents in the type II group predominantly died during the first hour after symptoms onset 16 (52%), while in the type I group, fatalities occurred between 1 h and 1 day, 27 (66%). The most common site of the intimal tear was the midportion of the ascending aorta, 45 (48%). The median ascending aorta size was 5 cm for the entire cohort, 5.2 cm for type I and 4.6 cm for type II (P < 0.045).

CONCLUSIONS

In this autopsy study of fatal acute aortic dissection, the median aortic size was below the current guideline threshold for elective repair. Type II acute aortic dissections were found more frequently than expected and were characterized by older age, advanced aortic atherosclerosis, smaller aortic size, a shorter interval from symptom onset to death and a higher frequency of syncope compared to type I dissection.
Compactness estimates for difference schemes for conservation laws with discontinuous flux
Authors: Karlsen Kenneth H , Towers John D
Published: January 2024

We establish quantitative compactness estimates for finite difference schemes used to solve nonlinear conservation laws. These equations involve a flux function $f(k(x,t),u)$, where the coefficient $k(x,t)$ is $BV$-regular and may exhibit discontinuities along curves in the $(x,t)$ plane. Our approach, which is technically elementary, relies on a discrete interaction estimate and one entropy function. While the details are specifically outlined for the Lax-Friedrichs scheme, the same framework can be applied to other difference schemes. Notably, our compactness estimates are new even in the homogeneous case ($k\equiv 1$).
Knock It Down? Unmaking, Deconstruction, and Destruction as/in Politics Research
Authors: Sjoberg Laura
Published: January 2024

Unmaking, deconstruction, and destruction are part of the everyday life of politics. This article makes an initial case for the plausibility of the argument that International Relations (IR) should expand its gaze and scholarly practice not only into material-aesthetic making, as suggested by the International Political Design (IPD) project, but also into material-aesthetic unmaking and destruction. If making is thinking, as Austin and Leander (2021) suggest, unmaking is also a scholarly enterprise, one that might be as intellectually significant as making, and have important implications for the project specifically and IR scholarship more generally. While I am not arguing that unmaking or destruction is always or even usually normatively good, I am arguing that it is intellectually important to understand and engage, and that thinking about unmaking has important normative implications for making. The first section of this article introduces the IPD project, and suggests that it is operationally and necessarily positive in its current instantiations, despite its criticality. The second section, drawing on inspirations as divergent as queer theory and realist IR, sets out an onto-epistemologically negative approach to IR/the world and uses that approach to problematize the positivity of the IPD project. The following three sections engage with potential negative approaches to making-as-scholarship: negative design, deconstruction, and destruction, engaging with the potential implications for both disciplinary inquiry in IR and the practices of IR scholars in the “world” as such. A conclusion talks about the importance of including deconstruction, demolition, destruction, tearing down, and unmaking in IR scholarship.
OHDSI Standardized Vocabularies—a large-scale centralized reference ontology for international data harmonization
Authors: Reich Christian , Ostropolets Anna , Ryan Patrick , Rijnbeek Peter , Schuemie Martijn , Davydov Alexander , Dymshyts Dmitry , Hripcsak George
Published: January 2024

Importance

The Observational Health Data Sciences and Informatics (OHDSI) is the largest distributed data network in the world encompassing more than 331 data sources with 2.1 billion patient records across 34 countries. It enables large-scale observational research through standardizing the data into a common data model (CDM) (Observational Medical Outcomes Partnership [OMOP] CDM) and requires a comprehensive, efficient, and reliable ontology system to support data harmonization.

Materials and methods

We created the OHDSI Standardized Vocabularies—a common reference ontology mandatory to all data sites in the network. It comprises imported and de novo-generated ontologies containing concepts and relationships between them, and the praxis of converting the source data to the OMOP CDM based on these. It enables harmonization through assigned domains according to clinical categories, comprehensive coverage of entities within each domain, support for commonly used international coding schemes, and standardization of semantically equivalent concepts.

Results

The OHDSI Standardized Vocabularies comprise over 10 million concepts from 136 vocabularies. They are used by hundreds of groups and several large data networks. More than 8600 users have performed 50 000 downloads of the system. This open-source resource has proven to address an impediment of large-scale observational research—the dependence on the context of source data representation. With that, it has enabled efficient phenotyping, covariate construction, patient-level prediction, population-level estimation, and standard reporting.

Discussion and conclusion

OHDSI has made available a comprehensive, open vocabulary system that is unmatched in its ability to support global observational research. We encourage researchers to exploit it and contribute their use cases to this dynamic resource.
Adaptations of bone and bone vasculature to muscular stretch training
Authors: Eazer Julia , Barsoum Mina , Smith Cole , Hotta Kazuki , Behnke Brad , Holmes Christina , Caldwell Jacob , Ghosh Payal , Reid-Foley Emily , Park Hyerim , Delp Michael , Muller-Delp Judy
Published: January 2024

The magnitude of bone formation and remodeling is linked to both the magnitude of strain placed on the bone and the perfusion of bone. It was previously reported that an increase in bone perfusion and bone density occurs in the femur of old rats with moderate aerobic exercise training. This study determined the acute and chronic effects of static muscle stretching on bone blood flow and remodeling. Old male Fischer 344 rats were randomized to either a naive or stretch-trained group. Static stretching of ankle flexor muscles was achieved by placement of a dorsiflexion splint on the left ankle for 30 min/d, 5d/wk for 4wk. The opposite hindlimb served as a contralateral control (nonstretched) limb. Bone blood flow was assessed during and after acute stretching in naive rats, and at rest and during exercise in stretch-trained rats. Vascular reactivity of the nutrient artery of the proximal tibia was also assessed in stretch-trained rats. MicroCT analysis was used to assess bone volume and micro-architecture of the trabecular bone of both tibias near that growth plate. In naive rats, static stretching increased blood flow to the proximal tibial metaphasis. Blood flow to the proximal tibial metaphysis during treadmill exercise was higher in the stretched limb after 4 wk of daily stretching. Daily stretching also increased tibial bone weight and increased total volume in both the proximal and distal tibial metaphyses. In the trabecular bone immediately below the proximal tibial growth plate, total volume and bone volume increased, but bone volume/total volume was unchanged and trabecular connectivity decreased. In contrast, intravascular volume increased in this region of the bone. These data suggest that blood flow to the tibia increases during bouts of static stretching of the hindlimb muscles, and that 4 wk of daily muscle stretching leads to bone remodeling and an increase in intravascular volume of the tibial bone.
Defining the Minimal Clinically Important Difference (MCID) and Patient Acceptable Symptom State (PASS) at 2 years following open gluteus medius and/or minimus repair
Authors: Rice Morgan W , Browning Robert B , Fenn Thomas W , Hevesi Mario , Nho Shane J
Published: January 2024

To define Minimally Clinically Important Difference (MCID) and Patient Acceptable Symptomatic State (PASS) threshold scores after open gluteus medius and/or minimus repair. Primary open gluteus medius and/or minimus repair patients from November 2013 to March 2020 were identified. Patient reported outcomes (PROs) were assessed preoperatively, 1- and 2-year follow-up, including the Hip Outcome Score Activities of Daily Living (HOS-ADL), modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (iHOT-12) and Visual Analog Scale (VAS) Pain. Thresholds for achieving a MCID and PASS postoperatively were calculated using the distribution method and receiver operator curve analysis; 25 patients (24 females, 1 male, age: 69 ± 6.8 years, body mass index: 26.9 ± 5.0 kg/m2) were included in final analyses. MCID threshold scores for HOS-ADL, mHHS, iHOT-12 and VAS Pain were calculated as 11.1, 6.2, 15.3 and 14.0, respectively. PASS threshold scores for each of the PROs were as follows: HOS-ADL (71.9), mHHS (60.0), iHOT-12 (49.2) and VAS Pain (36.8). MCID thresholds for HOS-ADL, mHHS, iHOT-12 and VAS Pain were achieved by 58.3%, 83.3%, 66.7% and 57.1% of patients, respectively. PASS thresholds for HOS-ADL, mHHS, iHOT-12 and VAS Pain were achieved by 52.4%, 44.8%, 65% and 59.1% of patients, respectively. Open gluteus medius and/or minimus repair results in a high rate of achievement of clinically significant outcomes at a minimum of 2 years postoperatively. MCID threshold values for HOS-ADL, mHHS, iHOT-12 and VAS Pain were 11.1, 6.2, 15.3 and 14.0, respectively. PASS threshold values for HOS-ADL, mHHS, iHOT-12 and VAS Pain were 71.9, 60.0, 49.2 and 36.8, respectively. The majority of patients achieved clinically significant outcomes with 81.3% and 77.3% achieving MCID and PASS for at least one PRO, respectively.
Periacetabular osteotomy with and without concomitant arthroscopy: a systematic review of evidence on post-operative activity levels and return to sport
Authors: Wyatt Phillip , Cole Sarah , Satalich James , Ernst Brady S , Cyrus John , Vap Alexander , O’Connell Robert
Published: January 2024

The purpose of this systematic review is to (i) compare post-operative activity levels after periacetabular osteotomy (PAO) versus PAO + HA (concomitant PAO and hip arthroscopy) using patient-reported outcomes that specifically assess activity and sports participation [Hip Disability and Osteoarthritis Outcome Score—Sport and Recreation subscale (HOOS-SR), University of California Los Angeles (UCLA) activity score, Hip Outcome Score—Sport-Specific Subscale (HOS-SSS)] and (ii) compare post-operative return to sport (RTS) data between PAO and PAO + HA groups. A systematic review of literature was conducted on 1 June 2023, utilizing PubMed, Cochrane and Embase (OVID). Articles were screened for inclusion using specific inclusion and exclusion criteria. Twenty-six out of 1610 articles met all inclusion criteria, without meeting any exclusion criteria. In the 12 studies containing only subjects who underwent PAO alone, 11 demonstrated an average score improvement in UCLA, HOOS-SR or HOS-SSS post-operatively (P < 0.05). In the three studies containing subjects who underwent PAO with concomitant HA, significant improvements were seen in the HOS-SS and UCLA scores (P < 0.05). In the five studies that directly compared UCLA, HOS-SSS and HOOS-SSS scores between PAO groups and PAO + HA groups, all demonstrated statistically significant improvement post-operatively (P < 0.05). The rate of RTS ranged from 63% to 90.8% among PAO studies and was found to be 81% in the single PAO + HA study that assessed RTS. When performed in patients with intra-articular pathology, concomitant PAO + HA may provide similar sport-related outcomes to PAO alone in patients without intra-articular pathology.