bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proper motion study of the 6.7 GHz methanol maser rings
Authors: Bartkiewicz A. , Sanna A. , Szymczak M. , Moscadelli L. , van Langevelde H. J. , Wolak P. , Kobak A. , Durjasz M. 
Published: April 2024

Context. Methanol masers at 6.7 GHz are well-known signposts of high-mass star-forming regions. Due to their high brightness, they enable us to derive the three-dimensional gas kinematics near protostars and young stars.
Aims. We aim to understand the origin of the ring-like structures outlined by methanol maser emission in a number of sources. This emission could be, a priori, spatially associated with an outflow and/or disc around a high-mass protostar. In cases of expansion or rotation, maser proper motions should be, for instance, diverging from the ring centre or perpendicular to the ring radius.
Methods. Using sensitive, three-epoch observations spanning over 8 yr with the European VLBI Network, we have started the most direct investigations of maser rings using very accurate proper motion measurements with uncertainties below ~1 km s−1.
Results. We present full results for the five targets of our sample, G23.207−00.377, G23.389+00.185, G28.817+00.365, G31.047+00.356, and G31.581+00.077, where proper motions show similar characteristics; maser cloudlets do not move inwards towards the centre of the rings but rather outwards. We also include the most circular source, G23.657−00.127, in the discussion as a reference. The magnitude of maser proper motions ranges from a maximum of about 13 km s−1 to 0.5 km s−1. In two of the five sources with a high number of maser spots (>100), namely G23.207−00.377 and G23.389+00.185, we show that the size of the best elliptical model, fitted to the distribution of persistent masers, increases in time in a manner similar to the case of G23.657−00.127. Moreover, we checked the separations between the pairs of spots from distinct regions, and we were able to assess that G28.817+00.365 and G31.047+00.356 can be interpreted as showing expanding motions. We analysed the profiles of single maser cloudlets and studied their variability. Contrary to single-dish studies, the interferometric data indicate variability of the emission of single-masing cloudlets.
Conclusions. In five of the six targets, namely, G23.207−00.377, G23.389+00.185, G23.657-00.127, G28.817+00.365, and G31.047+00.356, expansion motions prevail. Only in the case of G31.581+00.077 can a scenario of disc-like rotation not be excluded. Complementary observations of thermal tracers as well as searching for ultra-compact H II regions in the same sources are needed. Although the overall morphology of the maser emission has remained stable, the intensities of individual maser cloudlets varied from epoch to epoch, suggesting internal instabilities.
The AstraLux-TESS high spatial resolution imaging survey
Authors: Lillo-Box J. , Morales-Calderón M. , Barrado D. , Balsalobre-Ruza O. , Castro-González A. , Mendigutía I. , Huélamo N. , Montesinos B. , Vioque M. 
Published: April 2024

Context. Chance-aligned sources or blended companions can cause false positives in planetary transit detections or simply bias the determination of the candidate properties. In the era of high-precision space-based photometers, the need for high spatial resolution images has been demonstrated to be critical for validating and confirming transit signals. This already applied to theKeplermission, is now applicable to the TESS survey, and will be critical for the PLATO mission.Aims. In this paper we present the results of the AstraLux-TESS survey, a catalog of high spatial resolution images obtained with the AstraLux instrument at the Calar Alto observatory (Almería, Spain) in the context of the TESS Follow-up Observing Program.Methods. We used the lucky imaging technique to obtain high spatial resolution images from planet candidate hosts included mostly in two relevant regimes: exoplanet candidates belonging to the level one requirement of the TESS mission (planets with radiiR <4R⊕) and TESS planet candidates around intermediate-mass main-sequence stars.Results. Among the 185 planet host candidate stars observed, we found 13 (7%) to be accompanied by additional sources within a separation of 2.2 arcsec. Among them, six are not associated with sources in theGaiaDR3 catalog, thus contaminating the TESS light curve. Even if no contaminants have been detected, we can provide upper limits and probabilities to the possible existence of field contaminants through the sensitivity limits of our images. Among the isolated hosts, we can discard hazardous companions (bright enough to mimic a planetary transit signals) with an accuracy below 1% for all their planets.Conclusions. The results from this catalog are key to the statistical validation of small planets (prime targets of the TESS mission) and planets around intermediate-mass stars in the main sequence. These two populations of planets are difficult to confirm with the radial velocity technique because of the shallow amplitude of small planets and the high rotational velocities and low number of available spectral lines in the intermediate stellar mass regime. Our results also demonstrate the importance of this type of follow-up observation for future transit missions such as PLATO, even in theGaiaera.
The neutrino background from non-jetted active galactic nuclei
Authors: Padovani P. , Gilli R. , Resconi E. , Bellenghi C. , Henningsen F. 
Published: April 2024

Aims. We calculate the contribution to the neutrino background from the non-jetted active galactic nuclei (AGN) population following the recent IceCube association of TeV neutrinos with NGC 1068.
Methods. We exploited our robust knowledge of the AGN X-ray luminosity function and evolution and converted it to the neutrino band by using NGC 1068 as a benchmark, together with a theoretically motivated neutrino spectrum.
Results. The resulting neutrino background up to redshift 5 does not violate either the IceCube diffuse flux or the upper bounds for non-jetted AGN, although barely so. This is consistent with a scenario in which the latter class makes a substantial contribution mostly below 1 PeV, while jetted AGN, that is, blazars, dominate above this energy, in intriguing agreement with the dip in the neutrino data at ∼300 TeV. More and better IceCube data on Seyfert galaxies will allow us to constrain the fraction of neutrino emitters among non-jetted AGN.
Statement of the Uterus Commission of the Gynecological Oncology Working Group (AGO) on Neoadjuvant Chemotherapy Prior to Definitive Radiochemotherapy in Patients with Locally Advanced Cervical Cancer
Authors: Tempfer Clemens , Fehm Tanja , Vordermark Dirk , Marnitz-Schulze Simone , Beckmann Matthias W. , Denschlag Dominik , Brucker Sara , Wallwiener Markus , Eichbaum Michael , Ataseven Beyhan , Hillemanns Peter ,   für die Kommission Uterus der AGO
Published: April 2024

AbstractThe presentation of the results of the prospective randomized international multicenter GCIG INTERLACE trial at the 2023 congress of the European Society of Medical Oncology (ESMO) is likely to change the therapy for locally advanced cervical cancer. In the GCIG INTERLACE trial, six cycles of neoadjuvant chemotherapy administered weekly and consisting of carboplatin AUC2 and paclitaxel 80 mg/m2 followed by definitive radiochemotherapy with pelvic radiotherapy (40 – 50.4 Gray) and cisplatin (40 mg/m2 once a week for 5 weeks) and brachytherapy (total dose EQD2 at least 78 Gy at point A) (experimental arm) were compared with definitive radiochemotherapy alone (standard arm) in patients with locally advanced cervical cancer (Fédération Internationale de Gynécologie et dʼObstétrique [FIGO] 2008 stage IB1/node positive, IB2, II, IIIB and IVA) and was found to be significantly superior with significantly longer recurrence-free survival (hazard ratio [HR] 0.65;
95% confidence interval [CI] 0.64 – 0.91; p = 0.013) and significantly longer overall survival rates (HR 0.61; 95% CI: 0.40 – 0.91; p = 0.04) after 5 yearsʼ follow-up. After considering the results of the GCIG INTERLACE trial published at the congress, the Uterus Commission of the AGO is of the opinion that neoadjuvant chemotherapy with carboplatin AUC2 and paclitaxel 80 mg/m2 d1, q7, x6 may be offered to patients with locally advanced cervical cancer (FIGO stage IB1/node positive, IB2, II, IIIB and IVA) in addition to the current standard therapy after the patient has been informed about the risks, with the decision taken on a case-by-case basis. However, before this approach can be discussed at guideline level or defined as the new therapy standard, it will be necessary to wait until the data from the full publication are available.
Dual-Catalysis-Enabled Construction of Vicinal Stereogenic Centers through Diastereo- and Enantioselective Allylic Substitution
Authors: Su Bo , Yang Kai , Chen Lu 
Published: April 2024

AbstractVicinal stereogenic centers represent prevalent structural motifs in organic synthetic chemistry, and their construction poses a longstanding challenge. Transition-metal-catalyzed asymmetric allylic substitution has become a well-established enantioselective C–C bond-forming reaction. When these reactions involve a prochiral nucleophile and an allylic electrophile with a terminal substituent, the creation of vicinal stereogenic centers becomes feasible. However, despite remarkable achievements having been accomplished, realizing this transformation with precise control over both the enantio- and diastereoselectivity remains a significant challenge. To address the stereoselective challenges, the introduction of a second catalyst to the transition-metal-catalyzed asymmetric allylic alkylation to control the diastereoselectivity during C–C bond formation has proven particularly fruitful. In this short review, we aim to highlight recent advances in dual catalysis that enable diastereo- and enantioselective allylic substitutions.1	Introduction2	Construction of Vicinal Stereogenic Centers by Organo and Metal Dual Catalysis2.1	Chiral Phase-Transfer Catalysis and Transition-Metal Dual Catalysis2.2	Chiral Amine and Transition-Metal Dual Catalysis2.3	NHC and Transition-Metal Dual Catalysis2.4	Chiral Aldehyde and Transition-Metal Dual Catalysis2.5	Chiral Lewis Base and Transition-Metal Dual Catalysis3	Construction of Vicinal Stereogenic Centers by Metal and Metal Dual Catalysis3.1	Lewis Acidic Metal and Iridium Dual Catalysis3.2	Lewis Acidic Metal and Palladium Dual Catalysis3.3	Palladium and Ruthenium Dual Catalysis3.4	Other Advancements in the Construction of Vicinal Stereogenic Centers through Synergistic Bimetallic Catalysis Enabling Asymmetric Allylic Alkylation4	Conclusions and Future Outlook
Synthesis of α-Phenyl β-Enamino γ-Sultims: the New Horizon of the CSIC Reaction
Authors: Dobrydnev Alexey V. , Chuchvera Yaroslav O. , Tararina Valentyna , Chuchvera Inna , Ostapchuk Eugeniy N. , Popova Maria V. , Shishkina Svitlana V. , Volovenko Yulian M. 
Published: April 2024

AbstractHerein, we report the novel strategy for the synthesis of 4-enamino-5-phenyl-2,3-dihydroisothiazole 1-oxides (in other words α-phenyl β-enamino γ-sultims) based on the CSIC reaction. Particularly, readily available α-amino nitriles (the Strecker products) reacted with benzyl sulfinyl chloride to give the corresponding sulfinamides, which upon treatment with excess of LiHMDS converted into the target α-phenyl β-enamino γ-sultims. The method works well and tolerates strained 3- and 4-membered spirocyclic substituents. A preliminary in silico study indicated that the γ-sultim scaffold can be considered a promising pharmacophore template.
MesoHOPS: Size-invariant scaling calculations of multi-excitation open quantum systems
Authors: Citty Brian , Lynd Jacob K. , Gera Tarun , Varvelo Leonel , Raccah Doran I. G. B. 
Published: April 2024

The photoexcitation dynamics of molecular materials on the 10–100 nm length scale depend on complex interactions between electronic and vibrational degrees of freedom, rendering exact calculations difficult or intractable. The adaptive Hierarchy of Pure States (adHOPS) is a formally exact method that leverages the locality imposed by interactions between thermal environments and electronic excitations to achieve size-invariant scaling calculations for single-excitation processes in systems described by a Frenkel–Holstein Hamiltonian. Here, we extend adHOPS to account for arbitrary couplings between thermal environments and vertical excitation energies, enabling formally exact, size-invariant calculations that involve multiple excitations or states with shared thermal environments. In addition, we introduce a low-temperature correction and an effective integration of the noise to reduce the computational expense of including ultrafast vibrational relaxation in Hierarchy of Pure States (HOPS) simulations. We present these advances in the latest version of the open-source MesoHOPS library and use MesoHOPS to characterize charge separation at a one-dimensional organic heterojunction when both the electron and hole are mobile.
Metasurface-enhanced photochemical activity in visible light absorbing semiconductors
Authors: Paudel Yamuna , Chachayma-Farfan Diego J. , Alù Andrea , Sfeir Matthew Y. 
Published: April 2024

Heterogeneous photocatalysis is an important research problem relevant to a variety of sustainable energy technologies. However, obtaining high photocatalytic efficiency from visible light absorbing semiconductors is challenging due to a combination of weak absorption, transport losses, and low activity. Aspects of this problem have been addressed by multilayer approaches, which provide a general scheme for engineering surface reactivity and stability independent of electronic considerations. However, an analogous broad framework for optimizing light–matter interactions has not yet been demonstrated. Here, we establish a photonic approach using semiconductor metasurfaces that is highly effective in enhancing the photocatalytic activity of GaAs, a high-performance semiconductor with a near-infrared bandgap. Our engineered pillar arrays with heights of ∼150 nm exhibit Mie resonances near 700 nm that result in near-unity absorption and exhibit a field profile that maximizes charge carrier generation near the solid–liquid interface, enabling short transport distances. Our hybrid metasurface photoanodes facilitate oxygen evolution and exhibit enhanced incident photon-to-current efficiencies that are ∼22× larger than a corresponding thin film for resonant excitation and 3× larger for white light illumination. Key to these improvements is the preferential generation of photogenerated carriers near the semiconductor interface that results from the field enhancement profile of magnetic dipolar-type modes.
Confined and spontaneously transformed oxidation structures due to the intrinsic heterogeneous surface morphology of C3N monolayer
Authors: Luo Wenjin , Zhao Liang , Huang Zhijing , Ni Junqing , Tu Yusong 
Published: April 2024

Identifying the oxidation structure of two-dimensional interfaces is crucial to improve surface chemistry and electronic properties. Beyond graphene with only phenyl rings, a novel carbon-nitrogen material, C3N, presents an intrinsic heterogeneous surface morphology where each phenyl ring is encircled by six nitrogen atoms, yet its atomistic oxidation structure remains unclear. Here, combining a series of density functional theory calculations and ab initio molecular dynamics simulations, we demonstrate that thermodynamically favorable oxidation loci are confined to the phenyl ring, and kinetic transformations of oxidation structures are feasible along the phenyl ring, whereas those toward nitrogen atoms are proven to be extremely difficult. These results are attributed to the lower barrier of oxygen atom migration along the phenyl ring, while the significantly high barriers toward nitrogen atoms are due to the heterogeneous potential energy surface for oxygen–C3N interaction. This work highlights the significance of surface morphology on the characteristics of oxidation structure, offering insights into tunable electronic properties via confined interfacial oxidation.
The photochemistry of Rydberg-excited cyclobutanone: Photoinduced processes and ground state dynamics
Authors: Eng J. , Rankine C. D. , Penfold T. J. 
Published: April 2024

Owing to ring strain, cyclic ketones exhibit complex excited state dynamics with multiple competing photochemical channels active on the ultrafast timescale. While the excited state dynamics of cyclobutanone after π* ← n excitation into the lowest-energy excited singlet (S1) state has been extensively studied, the dynamics following 3s ← n excitation into the higher-lying singlet Rydberg (S2) state are less well understood. Herein, we employ fully quantum multiconfigurational time-dependent Hartree (MCTDH) simulations using a model Hamiltonian as well as “on-the-fly” trajectory-based surface-hopping dynamics (TSHD) simulations to study the relaxation dynamics of cyclobutanone following 3s ← n excitation and to predict the ultrafast electron diffraction scattering signature of these relaxation dynamics. Our MCTDH and TSHD simulations indicate that relaxation from the initially-populated singlet Rydberg (S2) state occurs on the timescale of a few hundreds of femtoseconds to a picosecond, consistent with the symmetry-forbidden nature of the state-to-state transition involved. There is no obvious involvement of excited triplet states within the timeframe of our simulations (&lt;2 ps). After non-radiative relaxation to the electronic ground state (S0), vibrationally hot cyclobutanone has sufficient internal energy to form multiple fragmented products including C2H4 + CH2CO (C2; 20%) and C3H6 + CO (C3; 2.5%). We discuss the limitations of our MCTDH and TSHD simulations, how these may influence the excited state dynamics we observe, and—ultimately—the predictive power of the simulated experimental observable.
Is HealthPathways viewed as a useful and trustworthy source of information by health professionals?
Authors: Tretheway Rebecca , Visser Victoria , Mollard Sarah 
Published: April 2024

Objective HealthPathways is a web-based platform designed for use during a consultation to offer health professionals locally agreed information to support clinical and referral decision making. This study aimed to investigate whether access to specific HealthPathways pages in the North Coast New South Wales (NSW) region increased during specific critical events. High pageviews is used as a proxy for platform usefulness, and/or trust as a source of up-to-date information. Methods Data were extracted from Google Analytics from December 2015 to December 2021. Descriptive statistics were generated for the total number of pageviews for all pages by month and year (2015–2021); for the top 15 most viewed pages in 2019, February–March 2020 inclusive (early COVID-19 pandemic period), 10–24 March 2021 (North Coast NSW region local disaster declaration period) and 26 June–11 October 2021 (NSW COVID-19 lockdown period); and for monthly pageviews for the Influenza Immunisation pathway (2016–2021). Results Access to specific pages in HealthPathways increased alongside the occurrence of critical events affecting the region. Spikes in access to specific pages were seen during COVID-19 lockdown periods, during natural disasters, as well as during the annual influenza season. Conclusions HealthPathways is viewed as a useful and trusted source of information for health professionals in the North Coast NSW region. HealthPathways provides an opportunity for timely dissemination of information during critical events, including natural disasters and emergencies.
Associations between receiving non-consensual image and video sexts and average sleep duration among adolescents and young adults
Authors: Ganson Kyle T. , O’Connor Carolyn , Nagata Jason M. , Testa Alexander , Jackson Dylan B. , Pang Nelson , Mishna Faye 
Published: April 2024

Background Sexting is the sending and receiving of nude or partially nude images or videos. Despite it being a part of contemporary relationships, it can have adverse effects. This is particularly the case when receiving non-consensual sexts. To date, there remains a gap in the literature on whether receiving non-consensual sexts is associated with poor sleep. Therefore, the aim of this study was to determine the association between receiving non-consensual sexts and average sleep duration. Methods Data from Wave 2 (2022) of the Canadian Study of Adolescent Health Behaviours (N = 906) were analysed. Multinomial logistic regression analyses were used to determine the association between receiving non-consensual sexts (both image and video) in the past 12 months and average sleep duration (≤5 h, 6 h, 7 h, 8 h, and ≥9 h) in the past 2 weeks. Analyses were stratified by gender. Results Girls and women who received non-consensual image and video sexts, compared to those who did not, were more likely to report ≤5 h of average sleep in the past 2 weeks, relative to 8 h of average sleep. There were no significant findings among boys and men. Conclusion Findings underscore that receiving non-consensual image and video sexts may negatively impact sleep among girls and women, which may be contextualised by trauma responses experienced because of gender-based sexual violence. Healthcare and mental health professionals should be made aware of this association to provide effective care to girls and women.
A realist interpretation of unitarity in quantum gravity
Authors: Sen Indrajit , Alexander Stephon , Dressel Justin 
Published: April 2024

Abstract
Unitarity is a difficult concept to implement in canonical quantum gravity because of state non-normalisability and the problem of time. We take a realist approach based on pilot-wave theory to address this issue in the Ashtekar formulation of the Wheeler–DeWitt equation. We use the postulate of a definite configuration in the theory to define a global time for the gravitational-fermionic system recently discussed in Alexander et al (2022 Phys. Rev. D 106 106012), by parameterising a variation of a Weyl-spinor that depends on the Kodama state. The total Hamiltonian constraint yields a time-dependent Schrodinger equation, without semi-classical approximations, which we use to derive a local continuity equation over the configuration space. We implement the reality conditions at the level of the guidance equation, and obtain a real spin-connection, extrinsic curvature and triad along the system trajectory. We obtain quantum corrections to deSitter spacetime from the guidance equation. The non-normalisable Kodama state is naturally factored out of the full quantum state in the conserved current density, opening the possibility for quantum-mechanical unitarity. We also give a pilot-wave generalisation of the notion of unitarity applicable to non-normalisable states, and show the existence of equilibrium density for our system. Lastly, we find unitary states in mini-superspace by finding an approximate solution to the Hamiltonian constraint.
The eye caustic of a ball lens
Authors: Quick Thomas , Grebe-Ellis Johannes 
Published: April 2024

Abstract
Lens phenomena, such as caustics, image distortions, and the formation of multiple images, are commonly observed in various refracting geometries, including raindrops, drinking glasses, and transparent vases. In this study, we investigate the ball lens as a representative example to showcase the capabilities of Berry’s eye caustic as an optical tool. Unlike the conventional paraxial approximation, the eye caustic enables a comprehensive understanding of image transformations throughout the entire optical space. Through experimental exploration, we establish the relationship between the eye caustic and traditional light caustics. Furthermore, we provide mathematical expressions to describe both the caustic and the image transformations that occur when viewing objects through the ball lens. This approach could be of interest for optics education, as it addresses two fundamental challenges in image formation: overcoming the limitations of the paraxial approximation and recognizing the essential role of the observer in comprehending lens phenomena.