European Physical Journal-special Topics最新文献

Radio antennas have become a standard tool for the detection of cosmic-ray air showers in the energy range above ${10}^{16}$ eV. The radio signal of these air showers is generated mostly due to the deflection of electrons and positrons in the geomagnetic field, and contains information about the energy and the depth of the maximum of the air showers. Unlike the traditional air-Cherenkov and air-fluorescence techniques for the electromagnetic shower component, radio detection is not restricted to clear nights, and recent experiments have demonstrated that the measurement accuracy can compete with these traditional techniques. Numerous particle detector arrays for air showers have thus been or will be complemented by radio antennas. In particular when combined with muon detectors, the complementary information provided by the radio antennas can enhance the total accuracy for the arrival direction, energy and mass of the primary cosmic rays. Digitization and computational techniques have been crucial for this recent progress, and radio detection will play an important role in next-generation experiments for ultrahigh-energy cosmic rays. Moreover, stand-alone radio experiments are under development and will search for ultrahigh-energy photons and neutrinos in addition to cosmic rays. This article provides a brief introduction to the physics of the radio emission of air showers, an overview of air-shower observatories using radio antennas, and highlights some of their recent results.

Coupled non-linear Schrödinger equations are crucial in describing dynamics of many-particle systems. We present a quantum imaginary time evolution (ITE) algorithm as a solution to such equations in the case of nuclear Hartree-Fock approach. Under a simplified Skyrme interaction model, we calculate the ground state energy of an oxygen-16 nucleus and demonstrate that the result is in agreement with the classical ITE algorithm. We examine bottlenecks and deficiencies in the quantum algorithm and suggest possible improvements.

This mini-review examines functional connectivity in resting-state functional magnetic resonance imaging (rs-fMRI) among opioid users. The goal is to summarize existing research data and clarify the implications of altered brain connectivity in this population. The first part of the review addresses the critical question of how opioid addiction influences the functional connectivity of key brain networks, such as the default mode network (DMN), salience network (SN), and executive control network (ECN). It examines the neurological basis of opioid addiction, the principles of rs-fMRI, different methodologies employed in this type of research, and inconsistencies and methodological challenges that complicate the interpretation of findings. The second part of the article presents findings derived from our ongoing research in the field. We tested 42 participants of whom 23 healthy controls and 19 patients with opioid use disorder. Each participant underwent an MRI scanning procedure comprised of structural, resting-state and task sequences. The neuroimaging data was processed using the CONN Toolbox running on MATLAB. Our preliminary rs-fMRI findings reveal significant disruptions in functional connectivity in individuals with opioid addiction within DMN and SN networks involved in cognitive functions such as decision-making and impulse control. The review concludes by emphasizing the importance of standardizing research practices, conducting longitudinal randomized studies, and developing a more holistic approach to understanding the effects of heroin addiction. These efforts would contribute to the development of personalized and effective intervention strategies.

Supplementary information: The online version contains supplementary material available at 10.1140/epjs/s11734-025-01591-2.

The dip-coating geometry, where a solid plate is withdrawn from or plunged into a liquid pool, offers a prototypical example of wetting flows involving contact-line motion. Such flows are commonly studied using the lubrication approximation approach which is intrinsically limited to small interface slopes and thus small contact angles. Flows for arbitrary contact angles, however, can be studied using a generalized lubrication theory that builds upon viscous corner flow solutions. Here we derive this generalized lubrication theory for viscoelastic liquids that exhibit normal stress effects and are modelled using the second-order fluid model. We apply our theory to advancing and receding contact lines in the dip-coating geometry, highlighting the influence of viscoelastic normal stresses for contact line motion at arbitrary contact angle.

Accurately sampling the membrane-bound conformations of peripheral membrane proteins (PMP) using classical all-atom molecular dynamics simulations (AAMD) is a formidable enterprise due to the wide rugged free energy landscape of the protein-membrane system. In general, AAMD-based extraction of binding geometry requires simulations of multiple systems with different initial user-defined binding poses that may not be exhaustive. As an alternative, advanced sampling methods are also applied to elucidate the membrane-binding mechanism of PMPs. But these techniques are generally computationally expensive and often depend on the choice of the collective variables (CV). In this work, we showcase the utility of CV-free replica exchange with the hybrid tempering (REHT) method in capturing the membrane-bound conformations of PMPs by testing it on the Osh4 amphipathic lipid-packing sensor (ALPS) motif, a 27 amino-acid membrane-binding peptide. We show that REHT samples all the membrane-bound conformations of the Osh4 ALPS peptide observed in AAMD simulations and does it in a highly efficient manner. We clearly show that, out of the two significant conformations, the peptide prefers horizontal conformations over vertical ones. In both the conformations, REHT captures all the vital residue-wise membrane contacts. The transition between the two configurations is not uncommon as our calculations reveal a ~1 kT free energy difference between the two conformations. Interestingly, from our simulations, we also find that the transition from vertical to horizontal conformation involves limited unfolding of the main helix's last turn. From our findings, we conclude that REHT samples the membrane-bound conformations of Osh4 ALPS peptide very efficiently and also provides additional insights and information that are often not available with regular piece-wise AAMD simulations. The method can be used as an efficient tool to explore the membrane-binding mechanisms of PMPs.

Background and study aims There is still a lack of evidence-based recommendations concerning endoscopic bougienage in benign esophageal strictures. Our study aimed to assess the relevance of the time interval between endoscopic dilation (ED) sessions with regard to endoscopic and clinical response. Patients and methods We performed a retrospective study including patients treated with endoscopic bougienage for a benign esophageal stricture in two German centers. Primary endpoint was the number of ED until freedom from dysphagia was achieved. Secondary endpoints were analyses on reaching a diameter of 15 mm and on achieving clinical freedom from symptoms. Results Between April 2014 and March 2020, bougienage was used as the primary treatment for benign esophageal strictures in 238 patients (194 patients in Center 1; 44 patients in Center 2). Both centers differed in their endoscopic bougienage regime: Center 1 was characterized by a higher frequency of interventions compared to Center 2 (median: 2 days [range 1-28] vs. 10 days [range 1-41]; P <0.001). Clinical response was achieved significantly earlier using the high-frequency regimen in all patients except for those with post-radiogen strictures, who clinically benefited from a low-frequency ED program. Accordingly, patients receiving higher-frequency ED reached a significantly larger post-dilation diameter and considerably larger diameter differences. Conclusions The results of our study demonstrate that a treatment concept consisting of higher-frequency bougienages seems to be more effective in treating most types of esophageal stricture. Radiogenic strictures were the only types of stenoses that benefited from a lower frequency ED program.