bluuebunny/crossref_metadata_2025 huggingface dataset:
Massive black holes at high redshifts from superconducting cosmic strings
Authors: Cyr Bryce , Jiao Hao , Brandenberger Robert
Published: August 2022

The observation of quasars at high redshifts presents a mystery in the theory of black hole formation. In order to source such objects, one often relies on the presence of heavy seeds ($M \approx 10^{4-6}{\rm M}_{\odot }$) in place at early times. Unfortunately, the formation of these heavy seeds are difficult to realize within the standard astrophysical context. Here, we investigate whether superconducting cosmic string loops can source sufficiently strong overdensities in the early universe to address this mystery. We review a set of direct collapse conditions under which a primordial gas cloud will undergo monolithic collapse into a massive black hole (forming with a mass of $M_{\rm BH} \approx 10^5{\rm M}_{\odot }$ at z ≈ 300 in our scenario), and systematically show how superconducting cosmic string loops can satisfy such conditions in regions of the Gμ − I parameter space.
Four new fast radio bursts discovered in the Parkes 70-cm pulsar survey archive
Authors: Crawford F , Hisano S , Golden M , Kikunaga T , Laity A , Zoeller D
Published: August 2022

We present four new fast radio bursts discovered in a search of the Parkes 70-cm pulsar survey data archive for dispersed single pulses and bursts. We searched dispersion measures (DMs) ranging between 0 and 5000 pc cm−3 with the HEIMDALL and FETCH detection and classification algorithms. All four of the fast radio bursts (FRBs) discovered have significantly larger widths (>50 ms) than almost all of the FRBs detected and catalogued to date. The large pulse widths are not dominated by interstellar scattering or dispersive smearing within channels. One of the FRBs has a DM of 3338 pc cm3, the largest measured for any FRB to date. These are also the first FRBs detected by any radio telescope so far, predating the Lorimer Burst by almost a decade. Our results suggest that pulsar survey archives remain important sources of previously undetected FRBs and that searches for FRBs on time-scales extending beyond ∼100 ms may reveal the presence of a larger population of wide-pulse FRBs.
Ensemble-based unsupervised machine learning method for membership determination of open clusters using Mahalanobis distance
Authors: Deb Sukanta , Baruah Amiya , Kumar Subhash
Published: August 2022

We present an improved method for the determination of membership of an open cluster using ensemble-based unsupervised machine learning techniques. The working principle of this method relies on two stages: (i) choosing a suitable range of three astrometric parameters (π, μαcos δ, μδ) using k-nearest neighbour (kNN) algorithm on the data downloaded for the cluster within a smaller search radius; (ii) application of two component Gaussian mixture modelling (GMM) on the resulting one dimensional Gaussian distribution of Mahalanobis distance (MD) of stars using the range of parameters obtained from the earlier step, but with the data downloaded within a bigger search radius. MD is calculated from the mean of each of the parameters in three dimensions. Thus the use of MD reduces the input of the GMM from the 3D parameter space into a 1D parameter space for the cluster membership determination. The method has been tested on a few clusters including those which have overlaps in some/all the parameters using the data obtained from the Gaia DR3 data base. It is found that the approach can easily separate the cluster members from the field stars. The clean colour-magnitude diagrams and similar direction of proper motions of the member stars obtained for the clusters shows that this method is very efficient and robust in segregating the cluster members from the field stars.
A photometry pipeline for SDSS images based on convolutional neural networks
Authors: Shi Jing-Hang , Qiu Bo , Luo A-Li , He Zhen-Dong , Kong Xiao , Jiang Xia
Published: August 2022

In this paper, we propose a convolutional neural network (CNN)-based photometric pipeline for the Sloan Digital Sky Survey (SDSS) images. The pipeline includes three main parts: the target source detection, the target source classification, and the photometric parameter measurement. The last part is completed using traditional methods. The paper mainly focuses on the first two parts and does not present the last. In the 1st part, a network named TSD-YOLOv4 is proposed to detect new sources missed by the SDSS photometric pipeline according to the PhotoObjAll catalogue of SDSS. In the second part, a target source classification network named TSCNet is constructed to classify sources into galaxies, quasars, and stars directly from photometric images. Experiments show that TSD-YOLOv4 outperforms other networks (Faster-RCNN, YOLOv4, YOLOX, etc.) in all metrics, with an accuracy of 0.988, a recall of 0.997, and an F1-score of 0.992, and TSCNet has good performance with a classification accuracy of 0.944 on the test set with 23 265 sources, and precision rates of 0.98, 0.908, and 0.918 for galaxies, quasars, and stars, respectively. On the other hand, the recall rates are 0.982, 0.903, and 0.921 for galaxies, quasars, and stars, respectively. The TSCNet has higher accuracy, fewer parameters, and faster inference speed than the leading astronomical photometric source classification network, the APSCNet model. In addition, the effect of magnitude distribution on the classification results is discussed in the experiments. The experiments prove that the proposed pipeline can be used as a powerful tool to supplement the SDSS photometric catalogue.
The GOGREEN survey: constraining the satellite quenching time-scale in massive clusters at z ≳ 1
Authors: Baxter Devontae C , Cooper M C , Balogh Michael L , Carleton Timothy , Cerulo Pierluigi , De Lucia Gabriella , Demarco Ricardo , McGee Sean , Muzzin Adam , Nantais Julie , Pintos-Castro Irene , Reeves Andrew M M , Rudnick Gregory H , Sarron Florian , van der Burg Remco F J , Vulcani Benedetta , Wilson Gillian , Zaritsky Dennis
Published: August 2022

We model satellite quenching at z ∼ 1 by combining 14 massive (1013.8 < Mhalo/M⊙ < 1015) clusters at 0.8 < z < 1.3 from the GOGREEN and GCLASS surveys with accretion histories of 56 redshift-matched analogues from the IllustrisTNG simulation. Our fiducial model, which is parametrized by the satellite quenching time-scale (τquench), accounts for quenching in our simulated satellite population both at the time of infall by using the observed coeval field quenched fraction and after infall by tuning τquench to reproduce the observed satellite quenched fraction versus stellar mass trend. This model successfully reproduces the observed satellite quenched fraction as a function of stellar mass (by construction), projected cluster-centric radius, and redshift and is consistent with the observed field and cluster stellar mass functions at z ∼ 1. We find that the satellite quenching time-scale is mass dependent, in conflict with some previous studies at low and intermediate redshift. Over the stellar mass range probed (M⋆ > 1010 M⊙), we find that the satellite quenching time-scale decreases with increasing satellite stellar mass from ∼1.6 Gyr at 1010 M⊙ to ∼0.6−1 Gyr at 1011 M⊙ and is roughly consistent with the total cold gas (HI + H2) depletion time-scales at intermediate z, suggesting that starvation may be the dominant driver of environmental quenching at z < 2. Finally, while environmental mechanisms are relatively efficient at quenching massive satellites, we find that the majority ($\sim 65{\!-\!}80{{\ \rm per\ cent}}$) of ultra-massive satellites (M⋆ > 1011 M⊙) are quenched prior to infall.
The redshift dependence of black hole mass distribution: is it reliable for standard sirens cosmology?
Authors: Mukherjee Suvodip
Published: August 2022

An upper limit on the mass of a black hole set by the pair-instability supernovae (PISN) process can be useful in inferring the redshift of the gravitational wave (GW) sources by lifting the degeneracy between mass and redshift. However, for this technique to work, it is essential that the PISN mass scale is redshift independent or at least has a predictable redshift dependence. We show that the observed PISN mass scale can get smeared and the position of the PISN mass scale is likely to exhibit a strong redshift dependence due to a combined effect from the non-zero value of the delay time between the formation of a star and the merging of two black holes and the metallicity dependence of PISN mass scale. Due to the unknown form of the delay-time distribution, the redshift dependence of the PISN mass cutoff of the binary black holes (BBHs) cannot be well characterized and will exhibit a large variation with the change in redshift. As a result, the use of a fixed PISN mass scale to infer the redshift of the BBHs from the observed masses will be systematically biased. Though this uncertainty is not severe for the third observation run conducted by the LIGO–Virgo–KAGRA collaboration, in the future this uncertainty will cause a systematic error in the redshift inferred from the PISN mass scale. The corresponding systematic error will be a bottleneck in achieving a few per cent precision measurements of the cosmological parameters using this method in the future.
Discovery and origin of the radio emission from the multiple stellar system KQ Vel
Authors: Leto P , Oskinova L M , Buemi C S , Shultz M E , Cavallaro F , Trigilio C , Umana G , Fossati L , Pillitteri I , Krtička J , Ignace R , Bordiu C , Bufano F , Catanzaro G , Cerrigone L , Giarrusso M , Ingallinera A , Loru S , Owocki S P , Postnov K A , Riggi S , Robrade J , Leone F
Published: August 2022

KQ Vel is a binary system composed of a slowly rotating magnetic Ap star with a companion of unknown nature. In this paper, we report the detection of its radio emission. We conducted a multifrequency radio campaign using the ATCA interferometer (band-names: 16 cm, 4 cm, and 15 mm). The target was detected in all bands. The most obvious explanation for the radio emission is that it originates in the magnetosphere of the Ap star, but this is shown unfeasible. The known stellar parameters of the Ap star enable us to exploit the scaling relationship for non-thermal gyro-synchrotron emission from early-type magnetic stars. This is a general relation demonstrating how radio emission from stars with centrifugal magnetospheres is supported by rotation. Using KQ Vel’s parameters the predicted radio luminosity is more than five orders of magnitudes lower than the measured one. The extremely long rotation period rules out the Ap star as the source of the observed radio emission. Other possible explanations for the radio emission from KQ Vel, involving its unknown companion, have been explored. A scenario that matches the observed features (i.e. radio luminosity and spectrum, correlation to X-rays) is a hierarchical stellar system, where the possible companion of the magnetic star is a close binary (possibly of RS CVn type) with at least one magnetically active late-type star. To be compatible with the total mass of the system, the last scenario places strong constraints on the orbital inclination of the KQ Vel stellar system.
Arp 58 and Arp 68: two M 51-type systems
Authors: Zasov Anatoly V , Saburova Anna S , Egorov Oleg V , Lander Vsevolod Yu , Makarov Dmitry I
Published: August 2022

We study two M 51-type systems Arp 68 and Arp 58, which strongly differ by their stellar masses, gas content, and environment. Long-slit spectral observations obtained at the Russian 6-m telescope were used to trace the distributions of a line-of-sight (LOS) velocity and a gas-phase oxygen abundance along the spectral cuts. Two systems are compared by their observed properties. We found a very strong large-scale non-circular motion of gas in both systems and a kpc-size saw-edged velocity profile along the tidal spiral arm of Arp 68, probably caused by the gas outflow due to the stellar feedback. A deep decrease of LOS velocity is also found in the ‘hinge’ region in Arp 58, where the inner spiral arm transforms into the tidal spiral arm, which was predicted earlier for M 51-type galaxies. Local sites of star formation and the satellites are compared with the evolutionary models at the colour–colour diagrams. Unlike the spiral galaxy Arp 58, the main galaxy in Arp 68 system is experiencing an ongoing burst of star formation. Gas-phase metallicity estimates show that Arp 58 has a higher metal abundance and reveals a shallow negative radial gradient of the gas-phase oxygen abundance. The emission gas in Arp 68 has noticeably lower metallicity than it is expected for a given luminosity of this galaxy, which may be connected with its space position in the local void.
A double-peaked Lyman-α emitter with a stronger blue peak multiply imaged by the galaxy cluster RXC J0018.5+1626
Authors: Furtak Lukas J , Plat Adèle , Zitrin Adi , Topping Micheal W , Stark Daniel P , Strait Victoria , Charlot Stéphane , Coe Dan , Andrade-Santos Felipe , Bradač Maruša , Bradley Larry , Lemaux Brian C , Sharon Keren
Published: August 2022

We report the discovery of a double-peaked Lyman-α (Ly α) emitter (LAE) at z = 3.2177 ± 0.0001 in VLT/MUSE data. The galaxy is strongly lensed by the galaxy cluster RXC J0018.5+1626 recently observed in the RELICS survey, and the double-peaked Ly α emission is clearly detected in the two counter images in the MUSE field of view. We measure a relatively high Ly α rest-frame equivalent width (EW) of EWLy α, 0 = (63 ± 2) Å. Additional spectroscopy with Gemini/GNIRS in the near-infrared (NIR) allows us to measure the H β, [O iii] λ4959 Å, and [O iii] λ5007 Å emission lines, which show moderate rest-frame EWs of the order of a few ∼10–100 Å, an [O iii] λ5007 Å/H β ratio of 4.8 ± 0.7, and a lower limit on the [O iii]/[O ii] ratio of >9.3. The galaxy has very blue UV-continuum slopes of βFUV = −2.23 ± 0.06 and βNUV = −3.0 ± 0.2, and is magnified by factors μ ∼ 7–10 in each of the two images, thus enabling a view into a low-mass ($M_{\star }\simeq 10^{7.5}\, \mathrm{M}_{\odot }$) high-redshift galaxy analogue. Notably, the blue peak of the Ly α profile is significantly stronger than the red peak, which suggests an inflow of matter and possibly very low H i column densities in its circumgalactic gas. To the best of our knowledge, this is the first detection of such a Ly α profile. Combined with the high lensing magnification and image multiplicity, these properties make this galaxy a prime candidate for follow-up observations to search for LyC emission and constrain the LyC photon escape fraction.
Gamma-ray burst data strongly favour the three-parameter fundamental plane (Dainotti) correlation over the two-parameter one
Authors: Cao Shulei , Dainotti Maria , Ratra Bharat
Published: August 2022

Gamma-ray bursts (GRBs), observed to redshift z = 9.4, are potential probes of the largely unexplored z ∼ 2.7–9.4 part of the early Universe. Thus, finding relevant relations among GRB physical properties is crucial. We find that the Platinum GRB data compilation, with 50 long GRBs (with relatively flat plateaus and no flares) in the redshift range 0.553 ≤ z ≤ 5.0, and the LGRB95 data compilation, with 95 long GRBs in 0.297 ≤ z ≤ 9.4, as well as the 145 GRB combination of the two, strongly favour the 3D Fundamental Plane (Dainotti) correlation (between the peak prompt luminosity, the luminosity at the end of the plateau emission, and its rest-frame duration) over the 2D one (between the luminosity at the end of the plateau emission and its duration). The 3D Dainotti correlations in the three data sets are standardizable. We find that while LGRB95 data have ∼50 per cent larger intrinsic scatter parameter values than the better-quality Platinum data, they provide somewhat tighter constraints on cosmological-model and GRB-correlation parameters, perhaps solely due to the larger number of data points, 95 versus 50. This suggests that when compiling GRB data for the purpose of constraining cosmological parameters, given the quality of current GRB data, intrinsic scatter parameter reduction must be balanced against reduced sample size.
Targeting CDK4 and 6 in Cancer Therapy: Emerging Preclinical Insights Related to Abemaciclib
Authors: Wander Seth A , O’Brien Neil , Litchfield Lacey M , O’Dea Declan , Morato Guimaraes Claudia , Slamon Dennis J , Goel Shom
Published: August 2022

Pharmacologic inhibitors of cyclin-dependent kinases 4 and 6 (CDK4 and 6) are approved for the treatment of subsets of patients with hormone receptor positive (HR+) breast cancer (BC). In metastatic disease, strategies involving endocrine therapy combined with CDK4 and 6 inhibitors (CDK4 and 6i) improve clinical outcomes in HR+ BCs. CDK4 and 6i prevent retinoblastoma tumor suppressor protein phosphorylation, thereby blocking the transcription of E2F target genes, which in turn inhibits both mitogen and estrogen-mediated cell proliferation. In this review, we summarize preclinical data pertaining to the use of CDK4 and 6i in BC, with a particular focus on several of the unique chemical, pharmacologic, and mechanistic properties of abemaciclib. As research efforts elucidate the novel mechanisms underlying abemaciclib activity, potential new applications are being identified. For example, preclinical studies have demonstrated abemaciclib can exert antitumor activity against multiple tumor types and can cross the blood-brain barrier. Abemaciclib has also demonstrated distinct activity as a monotherapeutic in the treatment of BC. Accordingly, we also discuss how a greater understanding of mechanisms related to CDK4 and 6 blockade highlight abemaciclib’s unique in-class properties, and could pave new avenues for enhancing its therapeutic efficacy.
Matching in Dynamic Imbalanced Markets
Authors: Ashlagi Itai , Nikzad Afshin , Strack Philipp
Published: August 2022

We study dynamic matching in exchange markets with easy- and hard-to-match agents. A greedy policy, which attempts to match agents upon arrival, ignores the positive externality that waiting agents provide by facilitating future matchings. We prove that the trade-off between a “thicker” market and faster matching vanishes in large markets; the greedy policy leads to shorter waiting times and more agents matched than any other policy. We empirically confirm these findings in data from the National Kidney Registry. Greedy matching achieves as many transplants as commonly used policies (1.8$\%$ more than monthly batching) and shorter waiting times (16 days faster than monthly batching).
Fibroblast expression of CD248 may contribute to exacerbation of microvascular damage during systemic sclerosis
Authors: Cipriani Paola , Ruscitti Piero , Di Cola Ilenia , Vomero Marta , Abbruzzese Franca , Di Nino Elena , Ross Rebecca , Del Galdo Francesco , Giacomelli Roberto
Published: August 2022

Objectives

CD248 is a glycoprotein, highly expressed on pericytes and fibroblasts (FBs), that is implicated in the fibrotic process. During angiogenesis, CD248 can promote vessel regression, binding multimerin-2 (MMRN-2). Thus, we investigated the expression of MMRN-2 in systemic sclerosis (SSc)-skin and of CD248 in isolated SSc-FBs. The anti-angiogenic property of CD248+ SSc-FBs was evaluated by co-culturing these cells with healthy control endothelial cells (HC-ECs). The apoptotic effect of CD248 on HC-ECs was evaluated. Finally, the ability of CD248 to prevent activation of VEGF receptor 2 (VEGFR2) was assessed.

Methods

By IF, MMRN-2 was investigated in SSc-skin and CD248 in SSc FBs. The anti-angiogenic property of CD248+ SSc-FBs was evaluated by HC-ECs/SSc-FBs co-cultures. Lentiviral-induced CD248 short-hairpin RNA delivery was employed for loss-of-function studies in SSc-FBs. HC-ECs were cultured in the presence of CD248 to assess apoptosis by IF and VEGFR2 phosphorylation by western blot.

Results

MMRN-2 expression was increased in skin SSc-ECs, whereas CD248 expression was increased in SSc-FBs. Functionally, CD248+-SSc-FBs suppressed angiogenesis in the organotypic model, as assessed by the reduction in total tube length of HC-ECs. This anti-angiogenetic behaviour was reversed by CD248 silencing. Furthermore, the presence of CD248 promoted the apoptosis of HC-ECs. Finally, CD248 prevented activation of VEGFR2 by reducing its phosphorylation after VEGF stimulation.

Conclusion

CD248 was anti-angiogenic in vitro due to a reduction in tube formation and to induction of apoptosis of ECs. Increased expression of CD248 in SSc could contribute to the microvascular rarefaction observed at the tissue level in SSc. Our results suggest a pathogenic role for CD248-MMRN-2 in SSc.
House dust mite‐induced Akt‐ERK1/2‐C/EBP beta pathway triggers CCL20‐mediated inflammation and epithelial–mesenchymal transition for airway remodeling
Authors: Park Shin‐Young , Kang Min‐Jeong , Jin Nuri , Lee So Young , Lee Yun Young , Jo Sungsin , Eom Jeong Yun , Han Heejae , Chung Sook In , Jang Kiseok , Kim Tae‐Hwan , Park Jungwon , Han Joong‐Soo
Published: August 2022

House dust mite (HDM) allergens cause inflammatory responses and chronic allergic diseases such as bronchial asthma and atopic dermatitis. Here, we investigate the mechanism by which HDM induces C–C chemokine ligand 20 (CCL20) expression to promote chronic inflammation and airway remodeling in an HDM‐induced bronchial asthma mouse model. We showed that HDM increased CCL20 levels via the Akt‐ERK1/2‐C/EBPβ pathway. To investigate the role of CCL20 in chronic airway inflammation and remodeling, we made a mouse model of CCL20‐induced bronchial asthma. Treatment of anti‐CCL20Ab in this mouse model showed the reduced airway hyper‐responsiveness and inflammatory cell infiltration into peribronchial region by neutralizing CCL20. In addition, CCL20 induced the Nod‐like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation through NLRP3 deubiquitination and transcriptional upregulation in BEAS‐2B cells. As expected, anti‐CCL20Ab markedly suppressed NLRP3 activation induced by CCL20. Moreover, HDM‐induced CCL20 leads to epithelial–mesenchymal transition in the lung epithelium which appears to be an important regulator of airway remodeling in allergic asthma. We also found that anti‐CCL20Ab attenuates airway inflammation and remodeling in an HDM‐induced mouse model of bronchial asthma. Taken together, our results suggest that HDM‐induced CCL20 is required for chronic inflammation that contributes airway remodeling in a mouse model of asthma.
BRAF increases endothelial cell stiffness through reorganization of the actin cytoskeleton
Authors: Hollósi Anna , Pászty Katalin , Bunta Bálint Levente , Bozó Tamás , Kellermayer Miklós , Debreczeni Márta Lídia , Cervenak László , Baccarini Manuela , Varga Andrea
Published: August 2022

The dynamics of the actin cytoskeleton and its connection to endothelial cell–cell junctions determine the barrier function of endothelial cells. The proper regulation of barrier opening/closing is necessary for the normal function of vessels, and its dysregulation can result in chronic and acute inflammation leading to edema formation. By using atomic force microscopy, we show here that thrombin‐induced permeability of human umbilical vein endothelial cells, associated with actin stress fiber formation, stiffens the cell center. The depletion of the MEK/ERK kinase BRAF reduces thrombin‐induced permeability prevents stress fiber formation and cell stiffening. The peripheral actin ring becomes stabilized by phosphorylated myosin light chain, while cofilin is excluded from the cell periphery. All these changes can be reverted by the inhibition of ROCK, but not of the MEK/ERK module. We propose that the balance between the binding of cofilin and myosin to F‐actin in the cell periphery, which is regulated by the activity of ROCK, determines the local dynamics of actin reorganization, ultimately driving or preventing stress fiber formation.
An overview of the current state of food desensitization
Authors: Galletta Francesca , Crisafulli Giuseppe , Arasi Stefania
Published: August 2022

Purpose of review

To highlight the current evidence on food desensitization in children with food allergy.

Recent findings

Food Allergen Specific Immunotherapy (FA-AIT) is currently recognised as a treatment option for treating children with allergy at least to the main common foods (i.e. milk, egg and peanut). The oral route of administration has been proven to be the most effective in achieving desensitisation. Efforts are devoted to overcome the current unmet needs mainly related to safety issues and long-term efficacy, as well as adherence to the treatment and improvement of health-related quality of life. In this perspective, alternative routes of administration and adjunctive treatments are under investigation.

The future of food allergy management is a personalised approach based on a shared decision-making that takes into account the needs of patients and families. Health professionals will be able to offer multiple treatment options, including FA-AIT with adjunctive or alternative therapies. Thus, patients should be correctly identified, using validated predictive factors, in order to select appropriate candidates for these therapies.
Outcomes of Reamed Intramedullary Nailing for Lower Extremity Diaphyseal Fractures in COVID-Positive Patients: A Multi-institutional Observational Study
Authors: Pectol Richard W. , Kavolus Matthew W. , Sneed Chandler R. , Albano Ashley Y. , Landy David C. , Aneja Arun ,   and the “COVID-ORTHO” research group
Published: August 2022

Objective:

To determine if reamed intramedullary nailing (IMN) of tibial and femoral shaft fractures exacerbated the hypercoagulable state of COVID infection, resulting in increased thromboembolic and pulmonary complications.

Design:

Retrospective chart review.

Setting:

Eleven Level I trauma centers.

Patients:

From January 1, 2020, to December 1, 2022, 163 patients with orthopaedic trauma and COVID positivity and 36 patients with tibial and femoral shaft fractures were included.

Intervention:

Reamed IMN.

Main Outcome Measures:

Incidence of postoperative thromboembolic and respiratory complications.

Results:

Thirty-six patients with a median age of 52 years (range, 18–92 years; interquartile range, 29–72 years) met criteria. There were 21 and 15 patients with femoral and tibial shaft fractures. There were 15 patients sustaining polytrauma; of which, 10 had a new injury severity score of >17. All patients underwent reamed IMN in a median of 1 day (range, 0–12 days; interquartile range = 1–2 days) after injury. Two patients developed acute respiratory distress syndrome (ARDS) and 3 pneumonia. No patients had pulmonary embolism, deep vein thrombosis, or died within 30 days.

Conclusion:

In this multi-institutional review of COVID-positive patients undergoing reamed IMN, there were no thromboembolic events. All patients developing pulmonary complications (ARDS or pneumonia) had baseline chronic obstructive pulmonary disease, were immune compromised, or sustained polytraumatic injuries with new injury severity score of >20. Given this, it seems reasonable to continue using reamed IMN for tibial and femoral shaft fractures after evaluation for COVID severity, comorbidities, and other injuries.

Levels of Evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Stress Hyperphenylalaninemia Is Associated With Mortality in Cardiac ICU: Clinical Factors, Genetic Variants, and Pteridines*
Authors: Wang Chao-Hung , Chen Wei-Siang , Liu Min-Hui , Lee Chi-Ying , Wang Mei-Ying , Liang Chung-Yu , Chu Chien-Ming , Wu Huang-Ping , Chen Wen-Hsin
Published: August 2022

OBJECTIVES:

Hyperphenylalaninemia predicts poor outcomes in patients with cardiovascular disease. However, the prognostic value and factors associated with stress hyperphenylalaninemia (SHP) were unknown in critical patients in the cardiac ICU.

DESIGN:

Prospective observational study.

SETTING:

Single-center, cardiac ICU in Taiwan.

PATIENTS:

Patients over 20 years old with Acute Physiology And Chronic Health Evaluation II scores greater than or equal to 15 and/or ventilatory support in the cardiac ICU.

INTERVENTIONS:

We measured plasma phenylalanine levels serially during patients’ stays in the ICU to investigate their prognostic value for 90-day mortality. Gene array was performed to identify genetic polymorphisms associated with SHP (phenylalanine level ≥ 11.2 μmol/dL) and to develop a Genetic Risk Score (GRS). We analyzed the associations between SHP and clinical factors and genetic variants and identified the correlation between pteridines and genetic variants.

MEASUREMENTS AND MAIN RESULTS:

The study enrolled 497 patients. Increased phenylalanine concentration was independently associated with increased mortality risk. Patients with SHP had a higher mortality risk compared with those without SHP (log rank = 41.13; p < 0.001). SHP was associated with hepatic and renal dysfunction and with genetic polymorphisms on the pathway of tetrahydrobiopterin (BH4) synthesis (CBR1 and AKR1C3) and recycling (PCBD2). Higher GRSs were associated with lower BH4 bioavailability in response to stress (p < 0.05). In patients without SHP at baseline, those with GRSs gretaer than or equal to 2 had a higher frequency of developing SHP during the ICU stay (31.5% vs 16.1%; p = 0.001) and a higher mortality risk (p = 0.004) compared with those with GRSs less than 2. In patients with SHP at baseline, genetic variants did not provide additional prognostic value.

CONCLUSIONS:

SHP in patients admitted to the ICU was associated with a worse prognosis. In patients without SHP, genetic polymorphisms associated with SHP measured using a GRS of greater than or equal to 2 was associated with the subsequent SHP and higher mortality risk.
#Menopause: the menopause ontology project
Authors: Trieu Elissa , Davenport Abigail P. , Kingsberg Sheryl A. , Iglesia Cheryl B.
Published: August 2022

Objective

To create a hashtag ontology specific to menopause.

Methods

This study analyzed tweets including the hashtag #menopause between November 2019 and November 2021. Tweets performed by international or national societies as well as expert social media influencers were included in the analysis. To analyze hashtag utilization amongst all Twitter users, hashtags from the “Top” tweets Twitter search function from October 2021 were also analyzed. Co-occurring hashtags were recorded as well as the type of user who performed the tweet during the “Top” tweets analysis. Social media influencers and experts reviewed and edited the hashtag list. The hashtags were then grouped by subject.

Results

We analyzed 382 tweets with #menopause. Of the users included in the “Top” tweets, 40% were patient advocates or advocacy groups; 38% were medical professionals, academics, societies, or journals; and 22% were general users. In total, 123 unique hashtags were identified. After social media influencer and expert review, 32 hashtags were included in the final ontology. The ontology was then grouped into the following categories based on subject matter: general, premature menopause, hormones, sexual function, and genital disorders.

Conclusions

Social media is an important tool for medical professionals and patients. Our study is the first to develop a hashtag ontology specific to menopause. Adoption of a hashtag ontology with standardized terminology by medical professionals may facilitate easier communication with peers and patients.
Gonadotropin-releasing hormone agonists for ovarian protection during breast cancer chemotherapy: a systematic review and meta-analysis
Authors: Li Zhen-Yu , Dong Ying-Li , Cao Xiao-Zhong , Ren Sha-Sha , Zhang Zhen
Published: August 2022

Importance

The increasing trend of delaying childbirth means that more women are being diagnosed with breast cancer before having given birth to their desired number of children. Although chemotherapy can significantly improve the prognosis of this population, it also causes ovarian damage, including premature ovarian insufficiency and infertility. Gonadotropin-releasing hormone agonists (GnRHa) have shown promising fertility protective activity in premenopausal women, but their clinical usage remains controversial.

Objective

Here, we conducted a meta-analysis to assess the efficacy of GnRHa when administered concurrently with chemotherapy that included cyclophosphamide in the prevention of chemotherapy-induced ovarian damage in premenopausal women.

Evidence Review

An extensive literature search was performed using the PubMed, Embase, and Cochrane databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were determined.

Findings

Eleven randomized controlled trials with a total of 1,219 participants were included in the analyses. A significantly higher number of women treated with GnRHa experienced the resumption of ovarian function after chemotherapy than those who did not receive this treatment (OR, 3.04; 95% CI, 1.87‐4.94; P < 0.001). Regarding spontaneous pregnancy, a statistically significant difference was observed only in hormone receptor-negative participants (OR, 2.06; 95% CI, 1.03‐4.11; P = 0.04).

Conclusions and Relevance

When treating premenopausal women with breast cancer, the administration of GnRHa concurrently with chemotherapy appeared to improve the resumption rate of ovarian function; however, the spontaneous pregnancy rate only improved in hormone receptor-negative patients. Thus, the use of GnRHa during chemotherapy may represent a feasible strategy for preserving ovarian function in women with breast cancer.
Prognostic Stratification of Multiple Myeloma Using Clinicogenomic Models: Validation and Performance Analysis of the IAC-50 Model
Authors: Mosquera Orgueira Adrián , González Pérez Marta Sonia , Díaz Arias José Ángel , Antelo Rodríguez Beatriz , Mateos María-Victoria
Published: August 2022

A growing need to evaluate risk-adapted treatments in multiple myeloma (MM) exists. Several clinical and molecular scores have been developed in the last decades, which individually explain some of the variability in the heterogeneous clinical behavior of this neoplasm. Recently, we presented Iacobus-50 (IAC-50), which is a machine learning-based survival model based on clinical, biochemical, and genomic data capable of risk-stratifying newly diagnosed MM patients and predicting the optimal upfront treatment scheme. In the present study, we evaluated the prognostic value of the IAC-50 gene expression signature in an external cohort composed of patients from the Total Therapy trials 3, 4, and 5. The prognostic value of IAC-50 was validated, and additionally we observed a better performance in terms of progression-free survival and overall survival prediction compared with the UAMS70 gene expression signature. The combination of the IAC-50 gene expression signature with traditional prognostic variables (International Staging System [ISS] score, baseline B2-microglobulin, and age) improved the performance well above the predictability of the ISS score. IAC-50 emerges as a powerful risk stratification model which might be considered for risk stratification in newly diagnosed myeloma patients, in the context of clinical trials but also in real life.
Private equity ownership of ophthalmology practices: how does it impact clinical research?
Authors: Chang Margaret A. , Pearlman Joel A.
Published: August 2022

Purpose of review

To explore the impact of private equity ownership of ophthalmology practices on the success of their clinical research programs.

Recent findings

Private equity partnership in the clinical research space has been steadily occurring over the past decades. In addition to contract research organizations, private equity groups have also consolidated multiple independent clinical research networks. By investing in an increasing number of retina practices, one private equity group is attempting to create a synergistic relationship between clinical practice and clinical research with the goal of supporting a larger, more robust clinical research network.

Although there are physician concerns about the potential deleterious effects of private equity ownership on clinical research capabilities, private equity support has the potential to be an important stimulus for clinical research growth.

Video abstract

http://links.lww.com/COOP/A48.
Transitioning from a standalone practice to a private equity-partnered practice and impact on clinical operations
Authors: Donnenfeld Eric
Published: August 2022

Purpose of review

Private equity has made significant inroads into the specialty of ophthalmology. The purpose of this review is to evaluate the effect of private equity on clinical operations in an ophthalmic practice.

Recent findings

Private equity had become an important source of capital and management expertise that has resulted in the consolidation of many ophthalmic practices as an alternative to working for a hospital system, insurance carrier, or independent private practice.

The recent growth of private equity presence in ophthalmology has resulted in significant changes in clinical operations. These changes in clinical operations include the increased importance of data management and data analytics, economies of scale, synergies, and introduction of patient-shared billing opportunities. Although physician input into clinical operations is decreased, provisional care decision-making can be maintained.
Current Practices Supporting Rigid Bronchoscopy—An International Survey
Authors: Matus Ismael , Wilton Shannon , Ho Elliot , Raja Haroon , Feng Lei , Murgu Septimiu , Sarkiss Mona
Published: August 2022

Background:

There are no guidelines for anesthesia or staff support needed during rigid bronchoscopy (RB). Identifying current practice patterns for RB pertinent to anesthesia, multidisciplinary teams, and algorithms of intra and post-procedural care may inform best practice recommendations.

Methods:

Thirty-three-question survey created obtaining practice patterns for RB, disseminated via email to the members of the American Association of Bronchology and Interventional Pulmonology and the American College of Chest Physicians Interventional Chest Diagnostic Procedures Network.

Results:

One hundred seventy-five clinicians participated. Presence of a dedicated interventional pulmonology (IP) suite correlated with having a dedicated multidisciplinary RB team (P=0.0001) and predicted higher likelihood of implementing team-based algorithms for managing complications (39.4% vs. 23.5%, P=0.024). A dedicated anesthesiology team was associated with the increased use of high-frequency jet ventilation (P=0.0033), higher likelihood of laryngeal mask airway use post-RB extubation (P=0.0249), and perceived lower rates of postprocedural anesthesia adverse effects (P=0.0170). Although total intravenous anesthesia was the most used technique during RB (94.29%), significant variability in the modes of ventilation and administration of muscle relaxants was reported. Higher comfort levels in performing RB are reported for both anesthesiologists (P=0.0074) and interventional pulmonologists (P=0.05) with the presence of dedicated anesthesia and RB supportive teams, respectively.

Conclusion:

Interventional bronchoscopists value dedicated services supporting RB. Multidisciplinary dedicated RB teams are more likely to implement protocols guiding management of intraprocedural complications. There are no preferred modes of ventilation during RB. These findings may guide future research on RB practices.
Iron status of blood donors
Authors: Spencer Bryan R. , Mast Alan E.
Published: August 2022

Purpose of review

This review examines recent research on the prevalence and importance of iron deficiency in blood donors, and on efforts to mitigate it.

Recent findings

Premenopausal females, teenagers, and high-frequency donors are at the highest risk for donation-induced iron deficiency, in both high-resource and low-resource settings. The physiology relating iron stores to hemoglobin levels and low hemoglobin deferral is well elucidated in blood donor populations, yet the clinical effects attributable to iron loss in the absence of anemia are challenging to identify. Expanded adoption of ferritin testing is improving donor management but may cause decreases in the blood supply from temporary donor loss. The potential for personalized donor management is emerging with development of computational models that predict individual interdonation intervals that aim to optimize blood collected from each donor while minimizing low hemoglobin deferrals.

Measures to reduce iron deficiency are available that can be deployed on a standardized or, increasingly, personalized basis. Blood centers, regulators, and donors should continue to evaluate different tactics for addressing this problem, to obtain a balanced approach that is optimal for maintaining adequate collections while safeguarding donor health.
Challenges in the Management of Wilms Tumor in a Developing Country: A Twenty Years’ Experience From a Single Center in Pakistan
Authors: Khan Muhammad Rahil , Maaz Ata Ur Rehman , Ashraf Muhammad Shamvil
Published: August 2022

Background:

Wilms Tumor (WT) is one of the most curable childhood cancers. High cure rates seen in the developed countries are not reproduced in developing countries. Lack of access to cancer treatment facilities, financial constraints, late presentation, and abandonment have previously been described. We reviewed our data over the last 20 years to highlight some of these challenges.

Methods:

This is a retrospective chart review of children with WT at our center up to the age of 18 years between 1 November 1997 and 30 November 2017. Demographic details, presentation characteristics and treatment details were recorded. Factors associated with poor outcome were analyzed.

Results:

Two hundred eleven children were registered; 117(55.5%) were males. Median age at presentation was 3 (range 0 to 18) years. Presentation data were available for 184/211 patients, staging details for 159/211 and metastatic status for 178/211. Of the available dataset, 60% presented without prior treatment, whereas 40% presented atleast after primary surgical excision. High-stage (stage III or above) disease was present in 79 (49.7%) patients; 61 (34.3%) was presented with metastases or recurrence; 63 (29.8%) abandoned or refused treatment; 99/172 (57.6%) patients finished treatment, 23 (13.4%) died during treatment, and 6 died before treatment. Of the 99 patients who finished treatment 83 (83.8%) are well off therapy; 15(15.2%) relapsed; 6 (40%) are alive after salvage therapy, while 9 (60%) died.

Conclusions:

Our data highlights the challenges of managing WT in resource poor environments. Prior surgery, incomplete staging work-up and abandonment are some of the most frequently encountered barriers. A multipronged approach is required to overcome these challenges.
Re-evaluate the Prognostic Value of Absolute Lymphocyte Count in Pediatric Immune Thrombocytopenia
Authors: Yang Ximei , Wan Xianghui , Huang Chao , Fu Jingjing , Hu Xiaolu , Le Ping , Ke Jiangwei
Published: August 2022

To re-evaluate the prognostic value of absolute lymphocyte count (ALC) in pediatric immune thrombocytopenia (ITP) from the perspective of age. A total of 242 ITP pediatric patients, including 141 newly diagnosed ITP (nITP), 89 chronic ITP (cITP), and 12 persistent ITP, were retrospectively reviewed for this study. These patients were divided into 3 groups according to age (group 1, ≤24 m; group 2, 24−72 m; and group 3, >72 m). The ALC detected at admission was significantly different between nITP and cITP patients without considering their age difference (5.22 vs. 3.55×109/L, P<0.001). However, no significant difference was discovered after age stratification (≤24 m: 6.52 vs. 5.34×109/L, P=0.161; 24−72 m: 3.78 vs. 3.63×109/L, P=0.748; >72 m: 2.53 vs. 2.40×109/L, P=0.748). ROC analysis showed that the prognostic value of ALC in ITP children was limited (area under curve (AUC): ≤24 m, 24−72 m, and >72 m were 0.591, 0.570, and 0.542, respectively). Analysis of covariance showed there was no significant difference in ALC between nITP and cITP when considering age as a covariate (P=0.131). Instead, the ROC showing that platelet to lymphocyte ratio (PLR) has prognostic value in pediatric ITP independent of age stratification (≤24 m: AUC, 0.688; 24−72 m: AUC, 0.741; >72 m: AUC, 0.680). In conclusion, there was no significant difference of ALC between nITP and cITP patients when stratified by different age groups, and PLR may be an optional prognostic indicator for ITP.
Seeking Standardized Definitions for HLA-incompatible Kidney Transplants: A Systematic Review
Authors: Jatana Sukhdeep S. , Zhao Hedi , Bow Laurine M. , Cozzi Emanuele , Batal Ibrahim , Horak Tillie , Amar-Zifkin Alexandre , Schinstock Carrie , Askar Medhat , Dadhania Darshana M. , Cooper Matthew , Naesens Maarten , Kraus Edward S. , Sapir-Pichhadze Ruth ,   on behalf of the Banff Antibody-Mediated Injury Working Group
Published: August 2022

Background.

There is no standard definition for “HLA incompatible” transplants. For the first time, we systematically assessed how HLA incompatibility was defined in contemporary peer-reviewed publications and its prognostic implication to transplant outcomes.

Methods.

We combined 2 independent searches of MEDLINE, EMBASE, and the Cochrane Library from 2015 to 2019. Content-expert reviewers screened for original research on outcomes of HLA-incompatible transplants (defined as allele or molecular mismatch and solid-phase or cell-based assays). We ascertained the completeness of reporting on a predefined set of variables assessing HLA incompatibility, therapies, and outcomes. Given significant heterogeneity, we conducted narrative synthesis and assessed risk of bias in studies examining the association between death-censored graft failure and HLA incompatibility.

Results.

Of 6656 screened articles, 163 evaluated transplant outcomes by HLA incompatibility. Most articles reported on cytotoxic/flow T-cell crossmatches (n = 98). Molecular genotypes were reported for selected loci at the allele-group level. Sixteen articles reported on epitope compatibility. Pretransplant donor-specific HLA antibodies were often considered (n = 143); yet there was heterogeneity in sample handling, assay procedure, and incomplete reporting on donor-specific HLA antibodies assignment. Induction (n = 129) and maintenance immunosuppression (n = 140) were frequently mentioned but less so rejection treatment (n = 72) and desensitization (n = 70). Studies assessing death-censored graft failure risk by HLA incompatibility were vulnerable to bias in the participant, predictor, and analysis domains.

Conclusions.

Optimization of transplant outcomes and personalized care depends on accurate HLA compatibility assessment. Reporting on a standard set of variables will help assess generalizability of research, allow knowledge synthesis, and facilitate international collaboration in clinical trials.
Temporal Characteristics of Neonatal Chick Retinal Ganglion Cell Responses: Effects of Luminance, Contrast, and Color
Authors: CS Deepak , Krishnan Abhijith , Narayan K S
Published: August 2022

We perform microelectrode array recordings of neonatal chick retina explants and report stimulus-dependent response properties of different retinal ganglion cell (RGC) types to various luminance and contrast adaptation conditions. The isolated single units indicate wavelength-sensitive response properties for all the retinal ganglion cell types recorded from. Responses to different luminance and contrast conditions investigated as a function of wavelength indicates a combination of adaptation and sensitization features in the recorded population of RGCs. We further demonstrate the presence of complementary response properties in most of the RGCs to blue (450 nm) and green (530 nm) light input and infer that luminance, contrast and color information are encoded in a wide variety of metrics such as latency, response event duration and pairwise correlations.