bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reacceleration of Galactic Cosmic Rays beyond the Knee at the Termination Shock of a Cosmic-Ray-driven Galactic Wind
Authors: Mukhopadhyay Payel , Peretti Enrico , Globus Noémie , Simeon Paul , Blandford Roger 
Published: August 2023

Abstract
The origin of cosmic rays (CRs) above the knee in the spectrum is an unsolved problem. We present a wind model in which interstellar gas flows along a nonrotating, expanding flux tube with a changing speed and cross-sectional area. CRs from Galactic sources, such as supernova remnants, which are coupled to the plasma via Alfvén waves, provide the main pressure source for driving this outflow. These CRs are then subject to diffusive shock reacceleration at the Galactic wind termination shock, which is located at a distance ∼200 kpc. Some of the highest-energy reaccelerated particles propagate upstream against the wind and can contribute to the petaelectronvolt to exaelectronvolt range of the spectrum. We analyze the conditions under which efficient reacceleration can occur and find that rigidities ∼10–40 PV can be obtained and that the termination shock may account for between 10% and 50% of the proton spectrum measured in IceCube/IceTop experiment. In our model, the termination shock is unable to fully explain the CR spectrum in the petaelectronvolt to exaelectronvolt range. The highest-energy particles that escape downstream from our termination shock, and similar shocks surrounding most galaxies, can be further accelerated by intergalactic shock fronts.
Discrepant Approaches to Modeling Stellar Tides and the Blurring of Pseudosynchronization
Authors: Townsend R. H. D. , Sun 孙 M. 萌 
Published: August 2023

Abstract
We examine the reasons for discrepancies between two alternative approaches to modeling small-amplitude tides in binary systems. The direct solution (DS) approach solves the governing differential equations and boundary conditions directly, while the modal decomposition (MD) approach relies on a normal-mode expansion. Applied to a model for the primary star in the heartbeat system KOI-54, the two approaches predict quite different behavior of the secular tidal torque. The MD approach exhibits the pseudosynchronization phenomenon, where the torque due to the equilibrium tide changes sign at a single, well-defined, and theoretically predicted stellar rotation rate. The DS approach instead shows “blurred” pseudosynchronization, where positive and negative torques intermingle over a range of rotation rates. We trace a major source of these differences to an incorrect damping coefficient in the profile functions describing the frequency dependence of the MD expansion coefficients. With this error corrected, some differences between the approaches remain; however, both are in agreement that pseudosynchronization is blurred in the KOI-54 system. Our findings generalize to any type of star for which the tidal damping depends explicitly or implicitly on the forcing frequency.
HOW-MHD: A High-order WENO-based Magnetohydrodynamic Code with a High-order Constrained Transport Algorithm for Astrophysical Applications
Authors: Seo Jeongbhin , Ryu Dongsu 
Published: August 2023

Abstract
Due to the prevalence of magnetic fields in astrophysical environments, magnetohydrodynamic (MHD) simulation has become a basic tool for studying astrophysical fluid dynamics. To further advance the precision of MHD simulations, we have developed a new simulation code that solves ideal adiabatic or isothermal MHD equations with high-order accuracy. The code is based on the finite-difference weighted essentially nonoscillatory (WENO) scheme and the strong stability-preserving Runge–Kutta (SSPRK) method. Most of all, the code implements a newly developed, high-order constrained transport (CT) algorithm for the divergence-free constraint of magnetic fields, completing its high-order competence. In this paper, we present the version in Cartesian coordinates, which includes a fifth-order WENO and a fourth-order five-stage SSPRK, along with extensive tests. With the new CT algorithm, fifth-order accuracy is achieved in convergence tests involving the damping of MHD waves in 3D space. And substantially improved results are obtained in magnetic loop advection and magnetic reconnection tests, indicating a reduction in numerical diffusivity. In addition, the reliability and robustness of the code, along with its high accuracy, are demonstrated through several tests involving shocks and complex flows. Furthermore, tests of turbulent flows reveal the advantages of high-order accuracy and show that the adiabatic and isothermal codes have similar accuracy. With its high-order accuracy, our new code would provide a valuable tool for studying a wide range of astrophysical phenomena that involve MHD processes.
Quasi-periodic Oscillations in GX 339−4 during the 2021 Outburst Observed with Insight-HXMT
Authors: Jin Y. J. , Wang W. , Chen X. , Tian P. F. , Liu Q. , Zhang P. , Wu H. J. , Sai N. 
Published: August 2023

Abstract
A new outburst of GX 339−4 in 2021 was monitored by the Hard X-ray Modulation Telescope (Insight-HXMT). By using the data of Insight-HXMT from 2021 February to March, we make an X-ray timing analysis of this new outburst. Based on the results of the count rates, hardness–intensity diagram, and power density spectrum (PDS), we confirm that the source exhibits spectral transitions from the low-hard state (LHS) to the hard-intermediate state (HIMS). During the transition from the LHS to the HIMS, low-frequency quasi-periodic oscillations (QPOs) are detected in the PDS. We found that these QPOs are all type C QPOs with centroid frequencies evolving from 0.1 to 0.6 Hz in the LHS and in the 1–3 Hz frequency range in HIMS. The QPO features above 50 keV are reported for the first time in this black hole by Insight-HXMT. The QPO rms stays stable with time but decreases with energy at a higher energy above ∼10 keV. We also find that the phase lag of the type C QPO is close to zero in the early outburst stage but becomes positive as the outburst evolves, with a hard lag of ∼0.6–1.2 rad in 50–100 keV. The implications of the phase lag in high energy bands and the possible physical mechanisms to explain those observations are also discussed.
AT 2021loi: A Bowen Fluorescence Flare with a Rebrightening Episode Occurring in a Previously Known AGN
Authors: Makrygianni Lydia , Trakhtenbrot Benny , Arcavi Iair , Ricci Claudio , Lam Marco C. , Horesh Assaf , Sfaradi Itai , Bostroem K. Azalee , Hosseinzadeh Griffin , Howell D. Andrew , Pellegrino Craig , Fender Rob , Green David A. , Williams David R. A. , Bright Joe 
Published: August 2023

Abstract
The optical-ultraviolet transient AT 2021loi is located at the center of its host galaxy. Its spectral features identify it as a member of the Bowen fluorescence flare (BFF) class. The first member of this class was considered to be related to a tidal disruption event, but enhanced accretion onto an already active supermassive black hole was suggested as an alternative explanation. Having occurred in a previously known unobscured active galactic nucleus, AT 2021loi strengthens the latter interpretation. Its light curve is similar to those of previous BFFs, showing a rebrightening approximately 1 yr after the main peak (which was not explicitly identified but might be the case in all previous BFFs). An emission feature around 4680 Å, seen in the preflare spectrum, strengthens by a factor of ∼2 around the optical peak of the flare and is clearly seen as a double-peaked feature then, suggesting a blend of N iii
λ4640 with He ii
λ4686 as its origin. The appearance of O iii
λ3133 and possible N iii
λλ4097, 4103 (blended with Hδ) during the flare further support a Bowen fluorescence classification. Here we present ZTF, ATLAS, Keck, Las Cumbres Observatory, NEOWISE-R, Swift AMI, and Very Large Array observations of AT 2021loi, making it one of the best-observed BFFs to date. It thus provides some clarity on the nature of BFFs but also further demonstrates the diversity of nuclear transients.
Advanced Γ Method for Small-scale Vortex Detection in the Solar Atmosphere
Authors: Yuan Yuyang , de Souza e Almeida Silva Suzana , Fedun Viktor , Kitiashvili Irina N. , Verth Gary 
Published: August 2023

Abstract
Ubiquitous vortical structures are considered to act as a natural source of various solar plasma phenomena, for example, a wide range of magnetohydrodynamic waves and jet excitations. This work aims to develop an advanced vortex detection algorithm based on the Γ method and using a separable convolution kernel technique. This method is applied to detect and analyze the photospheric vortices in 3D realistic magnetoconvection numerical and observational data. We present the advanced Γ method (AGM), and our results indicate that the AGM performs with better accuracy in comparison with the original Γ method. The AGM allows us to identify small- and large-scale vortices with no vortex interposition and without requiring the changing of the threshold. In this way, the nondetection issue is mostly prevented. It was found that the Γ method failed to identify the large and longer-lived vortices, which were detected by the AGM. The size of the detected vortical structures tends to vary over time, with most vortices shrinking toward their end. The vorticity at the center is also not constant, presenting a sharp decay as the vortex ceases to exist. Due to its capability of identifying vortices with minimum nondetection, the vortex properties—such as lifetime, geometry, and dynamics—are better captured by the AGM than by the Γ method. In this era of new high-resolution observation, the AGM can be used as a precise technique for identifying and performing statistical analysis of solar atmospheric vortices.
A Luminous Red Supergiant and Dusty Long-period Variable Progenitor for SN 2023ixf
Authors: Jencson Jacob E. , Pearson Jeniveve , Beasor Emma R. , Lau Ryan M. , Andrews Jennifer E. , Bostroem K. Azalee , Dong 董 Yize 一泽 , Engesser Michael , Gomez Sebastian , Guolo Muryel , Hoang Emily , Hosseinzadeh Griffin , Jha Saurabh W. , Karambelkar Viraj , Kasliwal Mansi M. , Lundquist Michael , Meza Retamal Nicolas E. , Rest Armin , Sand David J. , Shahbandeh Melissa , Shrestha Manisha , Smith Nathan , Strader Jay , Valenti Stefano , Wang Qinan , Zenati Yossef 
Published: August 2023

Abstract
We analyze pre-explosion near- and mid-infrared (IR) imaging of the site of SN 2023ixf in the nearby spiral galaxy M101 and characterize the candidate progenitor star. The star displays compelling evidence of variability with a possible period of ≈1000 days and an amplitude of Δm ≈ 0.6 mag in extensive monitoring with the Spitzer Space Telescope since 2004, likely indicative of radial pulsations. Variability consistent with this period is also seen in the near-IR J and K

s
bands between 2010 and 2023, up to just 10 days before the explosion. Beyond the periodic variability, we do not find evidence for any IR-bright pre-supernova outbursts in this time period. The IR brightness (

M

K

s

=
−
10.7

mag) and color (J − K

s
= 1.6 mag) of the star suggest a luminous and dusty red supergiant. Modeling of the phase-averaged spectral energy distribution (SED) yields constraints on the stellar temperature (

T

eff

=

3500

−
1400

+
800

K) and luminosity (

log
L

/

L

⊙

=
5.1
±
0.2

). This places the candidate among the most luminous Type II supernova progenitors with direct imaging constraints, with the caveat that many of these rely only on optical measurements. Comparison with stellar evolution models gives an initial mass of M
init = 17 ± 4 M
⊙. We estimate the pre-supernova mass-loss rate of the star between 3 and 19 yr before explosion from the SED modeling at

M

̇

≈
3
×

10

−
5

to 3 × 10−4
M
⊙ yr−1 for an assumed wind velocity of v

w
= 10 km s−1, perhaps pointing to enhanced mass loss in a pulsation-driven wind.
Photospheric Velocity Evolution of SN 2020bvc: Signature of r-process Nucleosynthesis from a Collapsar
Authors: Li Long , Zhong Shu-Qing , Dai Zi-Gao 
Published: August 2023

Abstract
Whether binary neutron star mergers are the only astrophysical site of rapid neutron-capture process (r-process) nucleosynthesis remains unknown. Collapsars associated with long gamma-ray bursts (GRBs) and hypernovae are promising candidates. Simulations have shown that outflows from collapsar accretion disks can produce enough r-process materials to explain the abundances in the universe. However, there is no observational evidence to confirm this result at present. SN 2020bvc is a broad-lined Type Ic (Ic-BL) supernova (SN) possibly associated with a low-luminosity GRB. Based on semi-analytic SN emission models with and without r-process materials, we perform a fitting to the multiband light curves and photospheric velocities of SN 2020bvc. We find that in a r-process-enriched model the mixing of r-process materials slows down the photospheric recession and therefore matches the velocity evolution better. The fitting results show that r-process materials with mass of ≈0.36 M
⊙ and opacity of ≈4 cm2 g−1 is needed to mix with about half of the SN ejecta. Our fitting results are weakly dependent on the nebular emission. Future statistical analysis of a sample of Type Ic-BL SNe helps us understand the contribution of collapsars to the r-process abundance.
Choosing Wisely: The Canadian Rheumatology Association Pediatric Committee’s List of Items Physicians and Patients Should Question
Authors: Lim Lillian , McMillan Tara , Chédeville Gaëlle , Lahiry Piya , Lee Jennifer J.Y. , Heale Liane D. , Human Andrea L. , McGrath Tara R. , MacQueen Sue E. , Stringer Elizabeth , Jariwala Mehul P. , Neufeld Kate M. , Soon Gordon S. , Spiegel Lynn R. , Luca Nadia J.C. 
Published: August 2023

ObjectiveTo develop a list of tests or treatments frequently used in pediatric rheumatology practice that may be unnecessary based on existing evidence.MethodsA Choosing Wisely (CW) working group composed of 16 pediatric rheumatologists, 1 allied health professional, 1 parent, and 1 patient used the Delphi method to generate, rank, and refine a list of tests and treatments that may be unnecessary or harmful. The items with the highest content agreement and perceived impact were presented in a survey to all Canadian Rheumatology Association (CRA) physicians who practice pediatric rheumatology. Respondents were asked to rate their agreement and impact, and to rank the items. Five items with the highest composite scores and 2 additional items selected by the CW working group were put forward for literature review.ResultsThe initial Delphi procedure generated 80 items. After 3 rounds, the list was narrowed to 13 items. The survey was completed by 41/81 (51%) CRA pediatric members across Canada. Respondent characteristics were similar to those of the CRA pediatric membership for self-reported gender, geographical location, and career stage. The highest composite score items were antinuclear antibody testing, drug toxicity monitoring, HLA-B27 testing, rheumatoid factor/anticyclic citrullinated peptide testing, and Lyme serology testing. Two additional items (numerous or repeated intraarticular corticosteroid injections, and autoinflammatory diseases genetic testing) were also selected. Literature review was performed for these 7 highest priority items.ConclusionWe have identified areas for quality improvement in the evaluation and treatment of rheumatic diseases in Canadian children.
Safe Patient Handling and Pressure Injury Prevention for Patients With Delayed Sternal Closure
Authors: Stokes Jason , Seabrooks Jessica , Yeung Yeu-Li , Richardson Angela , Pena Heather , Kester Kelly 
Published: August 2023

Background
Pressure injuries are associated with increased morbidity, mortality, and cost. Patients with delayed sternal closure after cardiac surgery are at increased risk of developing pressure injury because of their reduced mobility and inability to undergo complete skin assessment.

Local Problem
Safe patient handling of patients with delayed sternal closure is challenging because of mobility restrictions, leading to increased risk for patient and staff harm.

Methods
An interprofessional team composed of bedside nurses, ergonomic specialists, a wound ostomy continence nurse, and cardiothoracic surgeons developed a patient mobility protocol for patients with delayed sternal closure consisting of levitating the patient for thorough skin assessment and care. A multimodal educational strategy was used to disseminate the new protocol. Patient information was collected on the type of surgery, results of the levitation, completion of the skin assessment, and subsequent interventions. Staff injury related to this work was monitored.

Results
After implementation of the protocol, 84 levitations were performed including 50 patients. No staff injuries were reported. Comprehensive skin assessments and care were completed for 98% of patients. Five patients were identified with pressure injury development, and appropriate interventions were applied.

Discussion
A standardized patient mobility protocol for patients with delayed sternal closure that leveraged available equipment was successful in reducing the risk for injury among staff and patients. The protocol allowed assessment and care and thus also reduced the risk for pressure injury development in these patients.

Conclusion
Development of an innovative protocol to safely mobilize patients with delayed sternal closure resulted in improved patient care and increased staff safety.
Protocolization of Analgesia and Sedation Through Smart Technology in Intensive Care: Improving Patient Safety
Authors: Ojeda Isabel Muñoz , Sánchez-Cuervo Marina , Candela-Toha Ángel , Serrano-López Dolores R. , Bermejo-Vicedo Teresa , Alcaide-López-de-Lerma Juan Miguel 
Published: August 2023

Background
The risk of medication errors in intensive care units is high, primarily in the drug administration phase.

Local Problem
Management of high-alert medications within intensive care units in the study institution varied widely. The aim of this quality improvement project was to protocolize and centralize the management of high-alert medications in acute care settings and to implement smart intravenous infusion pump technology in intensive care units.

Methods
The project was conducted in 4 phases: (1) protocolization and standardization of intravenous mixtures, (2) centralization of intravenous mixture preparation in the Pharmacy Department, (3) programming of the smart pumps, and (4) dissemination and staged implementation of intravenous mixture protocols. Smart pumps (Alaris, CareFusion) were used to deliver the medicines, and the manufacturer’s software (Alaris Guardrails, CareFusion) was used to analyze data regarding adherence to the drug library and the number of programming errors detected.

Results
Morphine, remifentanil, fentanyl, midazolam, dexmedetomidine, and propofol were included. After implementation of the smart pumps, 3283 infusions were started; of these, 2198 were programmed through the drug library, indicating 67% compliance with the safety software. The pumps intercepted 398 infusion-related programming errors that led to cancellation or reprogramming of drug infusions.

Conclusions
Protocolization and centralization of the preparation of high-alert sedative and analgesic medications for critically ill patients and the administration of these drugs using smart pump technology decrease variability of clinical practice and intercept potentially serious medication errors.
My X-nit
Authors: Bharti Chhaya 
Published: August 2023

This article explains a technique of scleral fixation of intraocular lens (SFIOL) by using a 30-gauge (g) needle.

Background:
The X-nit needle by “Aurolab” uses a 26-g needle, while in this technique, a 30-g needle is used, thus reducing the incision size and relevant complications.

Purpose:
In this technique, glue or end-gripping forceps are not used, thus making it hassle free and more economical. There is no dependency on assistant; because of using 30 g needle, bleeding is minimal and wound healing is faster.

Synopsis:
A 30-g needle is bent at 3/4–1/4 junction (from the tip) and a piece of 240 silicon band is inserted into the needle to be used as a stopper. After completing vitrectomy, a 1.5-mm marking is done perpendicular to the limbus at 3’o clock and 9’o clock positions. Another marking is done 1.5 mm away from the first mark parallel to the limbus. A 30-g needle is inserted into partial-thickness sclera from the second mark toward the first marking, thus making a tunnel. The needle is penetrated into the sclera to enter in the vitreous cavity. The needle is then progressed toward the anterior vitreous cavity and brought out through the lip of previously made scleral tunnel in the superior quadrant. The tip of leading haptic of three-piece intraocular lens (IOL) is fed into the tip of needle and gradually, the needle is withdrawn. As soon as the tip of needle is visualized, the piece of band is gradually slipped into the haptic and the needle freed from the haptic. In a similar fashion, the trailing haptic is withdrawn from the opposite side. The bands are removed and the haptics are adjusted by pulling or pushing to centralize the IOL in the pupillary axis. Haptics are trimmed and ends are cauterized to make them blunt. Tunnel and conjunctiva are sutured with one or two (8-0) absorbable Vicryl sutures. The 25-g ports are removed and no suturing of ports is done.

Highlights:
It is a minimally invasive and glueless technique in which end-gripping forceps is not used. So, it is very economical with faster wound healing and minimal bleeding and no post-op hypotony. Since the temporal scleral flaps are not made and 30 g needle is used so minimal invasive. Astigmatiam induced by scleral tunnel is seen i;e about 0.75- 1.15 D of cylinder.

Video Link:
https://youtu.be/1msuS5KySOk

Key words: 30 gauge, intraocular lens, scleral fixation of IOL
Gonioscopy-assisted transluminal trabeculotomy in patients with advanced glaucoma
Authors: Dar Nimrod , Naftali Ben Haim Liron , Yehezkeli Veronika , Sharon Tal , Belkin Avner 
Published: August 2023

Purpose:
To evaluate the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in patients with advanced glaucoma.

Methods:
Records of 46 patients with advanced glaucoma were reviewed retrospectively in this single-center chart review. The main outcome measure was surgical success; intra-ocular pressure (IOP) and IOP lowering medication use were secondary outcome measures. Success was defined as an IOP of 18 mmHg or lower (criterion A) or 14 mmHg or lower (criterion B) and one of the following: IOP reduction >30% from baseline on the same or fewer medications or IOP ≤ of baseline on fewer medications as compared to baseline.

Results:
Forty-seven eyes were included in the analysis. The average mean deviation was -17.5 ± 7.2 dB (range −8.0 to -33.0). The average follow-up was 6.8 months (range 3.2–22.3). Success at 6 months was 91% for criterion A and 75% for criterion B (n = 33). Mean IOP was reduced from 19.3 ± 6 mmHg (12–40) on 3.7 ± 1.4 medications to 13.2 ± 5.8 mmHg on 1.6 ± 1.4 medications at the 6th post-operative month (P < 0.001 for both IOP and medications). At the last follow-up visit, 37 patients (78%) had an IOP of 14 mmHg or lower, and ten of these patients were unmedicated. Transient hyphema and IOP spikes were the most prevalent adverse events following surgery. Three eyes required further surgery for IOP control. None of the patients lost vision because of surgery.

Conclusions:
GATT is a viable surgical option in cases of advanced glaucoma. Careful patient selection and attentive post-operative management are imperative.