bluuebunny/crossref_metadata_2025 huggingface dataset:
Myocardial Infarction with Nonobstructive Coronary Artery (MINOCA)
Authors: Archana R.
Published: August 2021

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is diagnosed in almost equal to 5 to 6% of patients who present with acute myocardial infarction (AMI). Causes of MINOCA are varied. Appropriate diagnosis and evaluation is important to uncover the correct cause and prescribe specific therapies to treat the underlying cause.

Women with evidence of MINOCA are being increasingly recognized. The mechanisms underlying MINOCA, such as coronary microvascular spasm, represent a diagnostic and therapeutic challenge to medical fraternity, as there is neither a uniform nor comprehensive diagnostic strategy for accurate risk stratification, in the present scenario, for these patients.

Here, we are reporting a case of MINOCA, which is rare and incompletely evaluated.
Association between Low Urban Neighborhood Greenness and Hypertensive Disorders of Pregnancy
Authors: Tiako Max Jordan Nguemeni , McCarthy Clare , Meisel Zachary F. , Elovitz Michal A. , Burris Heather H. , South Eugenia
Published: August 2021

Objective Urban neighborhood greenness is associated with greater cardiovascular health in the general population, and with better pregnancy and neonatal outcomes. Hypertension in pregnancy is a leading cause of maternal mortality and long-term cardiovascular morbidity and mortality in women. We sought to examine the association between greenness and hypertensive disorders of pregnancy.

Study Design This study is a secondary analysis of a prospective cohort study of 1,943 women who received prenatal care from December 2013 to December 2016 at a single, urban, and tertiary academic medical center in Philadelphia, PA. Greenness measure was quantified via residential tree canopy cover within circumferential buffers of 100- and 500-meter radii around participants' homes. Associations between greenness and hypertensive disorders of pregnancy (defined as gestational hypertension or preeclampsia) were estimated by using multilevel logistic regression accounting for maternal sociodemographic information (race-ethnicity, insurance status, and age) medical history (diabetes, body mass index, smoking history, and parity), neighborhood deprivation index, and including 1,225 Philadelphia residents for whom key exposure and outcome data were available.

Results At baseline, the participants' mean (SD) age was 27.5 (5.9) years, (range: 14–44 years). The majority of participants were non-Hispanic Black (857, 70.2%). Participants with less residential tree canopy cover were significantly more likely to have hypertensive disorders of pregnancy. The multivariable-adjusted odds ratio of hypertensive disorders of pregnancy among participants with less than 10% compared with those with greater than 30% tree canopy cover was 2.14 (95% confidence interval [CI]: 1.11–4.15) within 100-meter buffer.

Conclusion In our cohort, greenness was associated with lower hypertensive disorders of pregnancy odds. Our findings add to evidence that greenness may confer health benefits and warrant further investigations in identifying whether there is a causal pathway through which greenness may be protective against hypertensive disorders of pregnancy.

Key Points
Hemostatic Biomarkers and Cancer Prognosis: Where Do We Stand?
Authors: Falanga Anna , Marchetti Marina , Russo Laura
Published: August 2021

Cancer patients are characterized by hypercoagulable state and an increased rate of thrombotic events, the most common being venous thromboembolism. Several hemostatic pathways that are significantly implicated in mechanisms of thromboembolic disease are also involved in growth, invasion, and metastatic spread of malignant cells as well in tumor-induced neo-angiogenesis. This close connection between cancer and the hemostatic system has prompted numerous studies on the role of alterations in the level plasma biomarkers of the different compartments of hemostasis in predicting cancer prognosis. In this review, we collect the results of several exemplificative studies that have evaluated clotting activation biomarkers in relation to different cancer outcomes with a final emphasis on current research and forthcoming directions in this field.
Early Vital Sign Differences in Very Low Birth Weight Infants with Severe Intraventricular Hemorrhage
Authors: Zanelli Santina A. , Abubakar Maryam , Andris Robert , Patwardhan Kavita , Fairchild Karen D. , Vesoulis Zachary A.
Published: August 2021

Objective Severe intraventricular hemorrhage (sIVH, grades 3 and 4) is a serious complication for very low birth weight (VLBW) infants and is often clinically silent requiring screening cranial ultrasound (cUS) for detection. Abnormal vital sign (VS) patterns might serve as biomarkers to identify risk or occurrence of sIVH.

Study Design This retrospective study was conducted in VLBW infants admitted to two level-IV neonatal intensive care units (NICUs) between January 2009 and December 2018. Inclusion criteria were: birth weight <1.5 kg and gestational age (GA) <32 weeks, at least 12 hours of systemic oxygen saturation from pulse oximetry (SpO2) data over the first 24 hours and cUS imaging. Infants were categorized as early sIVH (sIVH identified in the first 48 hours), late sIVH (sIVH identified after 48 hours and normal imaging in the first 48 hours), and no IVH. Infants with grades 1 and 2 or unknown timing IVH were excluded. Mean heart rate (HR), SpO2, mean arterial blood pressure (MABP), number of episodes of bradycardia (HR < 100 bpm), and desaturation (SpO2 < 80%) were compared.

Results A total of 639 infants (mean: 27 weeks' gestation) were included (567 no IVH, 34 early sIVH, and 37 late sIVH). In the first 48 hours, those with sIVH had significantly higher HR compared with those with no IVH. Infants with sIVH also had lower mean SpO2 and MABP and more desaturations <80%. No significant differences in VS patterns were identified in early versus late sIVH. Logistic regression identified higher HR and greater number of desaturations <80% as independently associated with sIVH.

Conclusion VLBW infants who develop sIVH demonstrate VS differences with significantly lower SpO2 and higher mean HR over the first 48 hours after birth compared with VLBW infants with no IVH. Abnormalities in early VS patterns may be a useful biomarker for sIVH. Whether VS abnormalities predict or simply reflect sIVH remains to be determined.

Key Points
PPP2R5D-Related Neurodevelopmental Disorder or Developmental and Epileptic Encephalopathy?: A Novel Phenotypic Description and Review of Published Cases
Authors: Madaan Priyanka , Kaur Amrit , Saini Lokesh , Paria Pradip , Vyas Sameer , Sharma Amit R. , Sahu Jitendra K.
Published: August 2021

Background Protein phosphatase 2 regulatory subunit B′ delta (PPP2R5D)-related neurodevelopmental disorder is caused by pathogenic variations in the PPP2R5D gene, product of which is involved in dephosphorylation. This is a rare disorder with description limited to case reports. Its phenotypic spectrum has expanded over the last decade.

Methods We report a child with a developmental and epileptic encephalopathy phenotype with a pathogenic PPP2R5D variant. This phenotype has not been previously reported. We also reviewed the previously published reports of patients with this disorder.

Results Including the index child, 28 cases (15 girls) were identified from nine relevant research items for analysis. All patients had developmental delay. History of seizures was observed in seven patients while macrocephaly was seen in nearly 80% of patients. Nonneurological manifestations were observed in 13 patients with the most common one being ophthalmological manifestations. The most common genetic variation was c.G592A (p.E198K). The common phenotypic associations of this variation were developmental delay, macrocephaly (11/15), and epilepsy (6/15).

Conclusion PPP2R5D gene variations should be suspected in children with developmental delay, autistic features, macrocephaly with or without epilepsy in the absence of any clear etiology. Dysmorphic features might provide a diagnostic clue. DEE phenotype may also be the presenting feature and might be an underreported entity.
The Acceptance of Interruptive Medication Alerts in an Electronic Decision Support System Differs between Different Alert Types
Authors: Bittmann Janina A. , Rein Elisabeth K. , Metzner Michael , Haefeli Walter E. , Seidling Hanna M.
Published: August 2021

Background Through targeted medication alerts, clinical decision support systems (CDSS) help users to identify medication errors such as disregarded drug–drug interactions (DDIs). Override rates of such alerts are high; however, they can be mitigated by alert tailoring or workflow-interrupting display of severe alerts that need active user acceptance or overriding. Yet, the extent to which the displayed alert interferes with the prescribers' workflow showed inconclusive impact on alert acceptance.

Objectives We aimed to assess whether and how often prescriptions were changed as a potential result of interruptive alerts on different (contraindicated) prescription constellations with particularly high risks for adverse drug events (ADEs).

Methods We retrospectively collected data of all interruptive alerts issued between March 2016 and August 2020 in the local CDSS (AiDKlinik) at Heidelberg University Hospital. The alert battery consisted of 31 distinct alerts for contraindicated DDI with simvastatin, potentially inappropriate medication for patients > 65 years (PIM, N = 14 drugs and 36 drug combinations), and contraindicated drugs in hyperkalemia (N = 5) that could be accepted or overridden giving a reason in free-text form.

Results In 935 prescribing sessions of 500 274 total sessions, at least one interruptive alert was fired. Of all interruptive alerts, about half of the sessions were evaluable whereof in total 57.5% (269 of 468 sessions) were accepted while 42.5% were overridden. The acceptance rate of interruptive alerts differed significantly depending on the alert type (p <0.0001), reaching 85.7% for DDI alerts (N = 185), 65.3% for contraindicated drugs in hyperkalemia (N = 98), and 25.1% for PIM alerts (N = 185).

Conclusion A total of 57.5% of the interruptive medication alerts with particularly high risks for ADE in our setting were accepted while the acceptance rate differed according to the alert type with contraindicated simvastatin DDI alerts being accepted most frequently.
The history of the birth of the Asakura–Oosawa theory
Authors: Oosawa Fumio
Published: August 2021

The history of the birth of the Asakura–Oosawa theory is presented.
A numerical study of separation and stagnation points for steady and unsteady flow over an elliptic cylinder near a moving wall
Authors: Zhu Jianxun , Holmedal Lars Erik
Published: August 2021

Flow separation around an elliptic cylinder with an aspect ratio of 0.4 near a moving wall is investigated numerically for Re∈[5,150] with G/D∈[0.1,2] (where G denotes the distance between the cylinder bottom and the bottom wall, while D denotes the major-axis length of the cylinder). Four steady flow patterns are identified in (Re,G/D)-space. A new flow pattern where only an anti-clockwise vortex is formed behind the lower part of the cylinder is observed for G/D≥0.4 with Re≤24. For steady flow, the upper separation point moves upstream as Re increases, while it is less affected by G/D. The lower separation moves first downstream and then upstream as Re increases for G/D≤0.4, while for G/D=0.7, only a large upstream movement is observed. The front stagnation point moves downstream toward the gap as Re decreases (for a given G/D) or as G/D decreases (for a given Re). The rear stagnation point moves first upward and then downward as Re increases for G/D≤0.4, while for G/D=0.7, the opposite behavior is observed. For unsteady flow, the stagnation and separation points oscillate. Here, both the amplitude and the frequency decrease as G/D decreases. The oscillation amplitude for the lower separation point is slightly larger than for the upper separation point due to the stronger vortex shedding behind the cylinder bottom caused by the enhanced velocity through the gap. This mechanism also leads to larger oscillation amplitudes for both the front stagnation point and the lower separation point at larger G/D than for the isolated cylinder.
N-polar ScAlN and HEMTs grown by molecular beam epitaxy
Authors: Wang Ping , Wang Ding , Wang Boyu , Mohanty Subhajit , Diez Sandra , Wu Yuanpeng , Sun Yi , Ahmadi Elaheh , Mi Zetian
Published: August 2021

Molecular beam epitaxy of single-phase wurtzite N-polar ScxAl1−xN (x ∼ 0.11–0.38) has been demonstrated on sapphire substrates by locking its lattice-polarity to the underlying N-polar GaN buffer. Coherent growth of lattice-matched Sc0.18Al0.82N on GaN has been confirmed by x-ray diffraction reciprocal space mapping of the asymmetric (105) plane, whereas lattice-mismatched, fully relaxed Sc0.11Al0.89N and Sc0.30Al0.70N epilayers exhibit a crack-free surface. The on-axis N-polar crystallographic orientation is unambiguously confirmed by wet chemical etching. High electron mobility transistors using N-polar Sc0.18Al0.82N as a barrier have been grown on sapphire substrates, which present the existence of well confined two-dimensional electron gas. A Hall mobility of ∼564 cm2/V s is measured for a 15-nm-thick Sc0.18Al0.82N barrier sample with a sheet electron concentration of 4.1 × 1013 cm−2, and the corresponding sheet resistance is as low as 271 Ω/sq. The polarity-controlled epitaxy of ScxAl1−xN provides promising opportunities for applications in high-frequency and high-power electronic and ferroelectric devices.
The effect of thermal annealing on the optical properties of Mg-doped zincblende GaN epilayers
Authors: Dyer D. , Church S. A. , Jain M. , Kappers M. J. , Frentrup M. , Wallis D. J. , Oliver R. A. , Binks D. J.
Published: August 2021

The effects of thermal annealing on the optical properties of Mg-doped cubic zincblende GaN epilayers grown by metalorganic chemical vapor deposition on 3C-SiC/Si (001) substrates are investigated. The photoluminescence spectra show near band edge features and a blue luminescence band that depend on Mg concentration, temperature, and excitation power density. Annealing the sample in a N2 atmosphere causes the intensity of the blue band to increase by a factor of 5. Power dependent photoluminescence measurements show a reduction in the laser excitation density required for saturation of the blue band after annealing, indicating an increase in the recombination lifetime. Time decay measurements confirm this increase, which is attributed to a reduction in the concentration of non-radiative defects after annealing. The results presented here are compared to those reported previously for Mg-doped hexagonal wurtzite GaN.
Stability of two-layer flows past slippery surfaces. II. Inclined channels
Authors: Mishra Himanshu , Roy Anubhab , Vengadesan S.
Published: August 2021

In this paper, the linear stability characteristics of a two-layered liquid–liquid flow in an inclined channel with slippery walls are investigated. Previous studies on two-layered inclined channel flows have observed the presence of multiple base state flow profiles, two for countercurrent flow and up to three base states for co-current flow. The role of wall slip on the multiple base states associated with each holdup solution is analyzed here. Subsequently, a linear stability analysis, using a combination of a long-wave asymptotic analysis and finite wavenumber numerical calculation, is carried out with the slip boundary condition. Neutral stability boundaries are presented for each base state, with comparisons made with the previous results obtained for the no-slip boundary condition. It was found that the wall slip could have both stabilizing and destabilizing effects depending on the flow rates and the value of holdup—the location of an interface.
Strain rate-dependent tensile response of glassy silicon nanowires studied by accelerated atomistic simulations
Authors: Zhang Yanming , Cao Penghui , Deng Binghui , Huang Liping , Shi Yunfeng
Published: August 2021

Mechanical properties of glassy nanowires have been intensively investigated recently by both nanomechanical experiments and atomic-level simulations. Unfortunately, there exists a huge gap in the strain rate of the nanomechanical tests between experiments and simulations, which makes it difficult to compare results even for the same material system. Using accelerated atomistic simulations based on a self-learning metabasin escape algorithm, here, we report the tensile mechanical properties of amorphous Stillinger–Weber silicon nanowires with different intrinsic ductility under strain rates ranging from 1010 to 10−1 s−1. It is found that both brittle and ductile glassy silicon nanowires display weakened strength with a decreasing strain rate, in agreement with the cooperative shear model. Moreover, as the strain rate decreases, the amount of plasticity remains unchanged for the brittle nanowires, yet it decreases for the ductile ones. Such deteriorated plasticity in ductile glassy nanowires is caused by enhanced strain localization at low strain rates. Lastly, we show that via the distance matrix of nonaffine displacement, a more hierarchical potential energy landscape is responsible for the higher strain localization propensity in ductile silicon glassy nanowires.
Palliative care and COVID-19 in the Australian context: a review of patients with COVID-19 referred to palliative care
Authors: Mendis Ruwani , Haines Anita , Williams Loretta , Mitchener Kirsten , Grimaldi Fiona , Phillips Marianne , Shaw Margaret , Nguyen Thy Pham Hoai , Dabscheck Adrian , Spruijt Odette , Coperchini Maria
Published: August 2021

Objective Palliative care has played a key role in the response to the coronavirus disease 2019 (COVID-19) pandemic in Australia. This review of consecutive patients with COVID-19 referred to the palliative care consultancy service of a tertiary health service in Melbourne describes the palliative care experience with COVID-19 in Australia. Methods The experiences of 55 patients (median age 86 years; interquartile range (IQR) 81–90 years; 55% male; median Charlson comorbidity score 6 (IQR 5–8); 85% with Australia-modified Karnofsky Performance Status ≤50; 67% from residential aged care facilities) were reviewed to collect relevant data points. Results Most patients were referred for end-of-life care with symptoms including dyspnoea (80%) and agitation/delirium (60%). Continuous subcutaneous infusions were commenced in 71% of patients, with the most frequent medications being opioids and benzodiazepines in relatively small doses; 81% required ≤20 mg subcutaneous morphine equivalent and 64% required ≤10 mg subcutaneous midazolam over 24 h. Fifty patients (91%) died in hospital and the median time from palliative care referral to death was 3 days (IQR 1–5 days). Five patients were discharged back to residential aged care facilities. Overall, 80% of referrals were from the aged care team. Conclusion Our patients had similar demographics, symptoms, medication needs and outcomes to patients in similar settings overseas. We found the symptom management of patients with COVID-19 to be generally straightforward. However, the psychosocial needs of patients were predominant and contributed to complexity. This study highlights the need for well-integrated relationships between the palliative care consultancy service and the diverse range of key treating teams involved in the delivery of pandemic health care. What is known about the topic? Palliative care has played a key role in the response to the COVID-19 pandemic in Australia. There is limited research describing the Australian palliative care experience with the COVID-19 pandemic. What does this paper add? Patients with COVID-19 referred to a hospital-based palliative care consultancy service in Australia had similar demographic characteristics, symptoms, medication needs and outcomes to patients with COVID-19 referred to other palliative care services in the UK and the US. There were significant psychosocial issues affecting patients, families and staff in the context of the pandemic. What are the implications for practitioners? This study highlights the need for well-functioning working relationships between the palliative care consultancy service and other hospital teams that can be leveraged at a time of crisis, such as a pandemic, to provide optimal palliative care to patients.
METTL14 facilitates global genome repair and suppresses skin tumorigenesis
Authors: Yang Zizhao , Yang Seungwon , Cui Yan-Hong , Wei Jiangbo , Shah Palak , Park Gayoung , Cui Xiaolong , He Chuan , He Yu-Ying
Published: August 2021

Significance

N
6
-methyladenosine (m
6
A) RNA methylation is the most-abundant modification in messenger RNA and noncoding RNA in eukaryotic cells. However, the regulatory and functional role of m
6
A in response to DNA damage remains poorly understood. Here, using the combination of in vitro models and mice with skin-specific genetic deletion of the key m
6
A writer factor METTL14, we have demonstrated a crucial role of METTL14 in global genome repair and ultraviolet B (UVB) radiation–induced skin tumorigenesis. Such a role of METTL14 may serve as an emerging epitranscriptomic mechanism to coordinate RNA metabolism and UVB damage response in tumorigenesis. We anticipate that these findings may be translated into potential strategies to improve genome stability and cancer prevention by targeting the METTL14 pathway.
Dual-mechanism estrogen receptor inhibitors
Authors: Min Jian , Nwachukwu Jerome C. , Min Charles K. , Njeri Jacqline W. , Srinivasan Sathish , Rangarajan Erumbi S. , Nettles Charles C. , Sanabria Guillen Valeria , Ziegler Yvonne , Yan Shunchao , Carlson Kathryn E. , Hou Yingwei , Kim Sung Hoon , Novick Scott , Pascal Bruce D. , Houtman Rene , Griffin Patrick R. , Izard Tina , Katzenellenbogen Benita S. , Katzenellenbogen John A. , Nettles Kendall W.
Published: August 2021

Significance

To address the unmet clinical need for effectively suppressing estrogen receptor (ER) activity with both de novo resistance and in advanced ER-positive breast cancers that are resistant to standard-of-care antiestrogens, we have developed dual-mechanism ER inhibitors (DMERIs) that employ two distinct ER-targeting moieties. These DMERI elicited noncanonical structural perturbations of the receptor ligand-binding domain and stabilized multiple antagonist substates within the dimer to generate highly efficacious antagonism of proliferation in ER-positive breast cancer cells and in allele-specific resistance models. This work reveals conformational modes by which the activity of ER can be effectively suppressed to block breast cancer proliferation.
Structural basis for the activation of the DEAD-box RNA helicase DbpA by the nascent ribosome
Authors: Wurm Jan Philip , Glowacz Katarzyna-Anna , Sprangers Remco
Published: August 2021

Significance

DEAD-box RNA helicases are essential cellular enzymes that remodel misfolded RNA structures in an adenosine triphosphate (ATP)-dependent process. The DEAD-box helicase DbpA is involved in the complex and highly regulated process of ribosome maturation. To prevent wasteful hydrolysis of ATP by DbpA, the enzyme is only active when bound to maturing ribosomes. Here, we elucidate the structural basis behind this important regulatory mechanism and find that the recruited ribosome substrate is able to stabilize the catalytically important closed state of the helicase. In addition, our data identify the natural site of action for DbpA in the maturing ribosome and provide a molecular explanation for the observed ribosome maturation defects that result from the overexpression of a DbpA mutant form.
Protease cleavage of RNF20 facilitates coronavirus replication via stabilization of SREBP1
Authors: Zhang Shilei , Wang Jingfeng , Cheng Genhong
Published: August 2021

Significance

SARS-CoV-2 has a main protease for viral polyprotein processing. But too few studies addressed this protease’s target of host factors. Here, we screen nearly 300 interferon-stimulated genes (ISGs) and identify that RNF20 is cleaved by 3Clpro, which prevents SREBP1 degradation mediated by RNF20/RNF40 complex, thus promoting SARS-CoV-2 replication. Our study will encourage people to develop drugs against not only coronavirus protease but also host factors.
Rapid sulfuric acid–dimethylamine nucleation enhanced by nitric acid in polluted regions
Authors: Liu Ling , Yu Fangqun , Du Lin , Yang Zhi , Francisco Joseph S. , Zhang Xiuhui
Published: August 2021

Significance

Nucleation of atmospheric aerosol particles can contribute to nearly half of global cloud condensation nuclei. Nitric acid (NA) is one of the most abundant atmospheric pollutants. A recent study suggested that NA is likely to participate in the sulfuric acid–ammonia nucleation only in the clean and cold upper free troposphere, but its role in the polluted atmospheric boundary layer was not considered. Herein, we found that NA can extensively participate in and significantly enhance the predominant sulfuric acid–dimethylamine nucleation in the polluted boundary layer. Thus, controls on the emissions of nitrogen pollutants are likely significant for the reduction of particulate pollution, especially in the polluted regions.
The Meaningfulness of Grandiose and Vulnerable Narcissism in Forensic Mental Health Rehabilitation Practice: A Systematic Review
Authors: Keune Lobke H. , de Vogel Vivienne , Eisenberg Mara , van Marle Hjalmar J. C.
Published: August 2021

Narcissism is a personality construct with grandiose, and vulnerable aspects, that are interconnected through antagonistic characteristics. While antagonism is strongly related to antisocial behavior, the role of narcissism remains underexplored in offender rehabilitation practice. Research in non-forensic samples has already shown promising results in the differential associations for grandiose and vulnerable narcissism in relation to violent and antisocial behavior and treatment responsiveness that could be relevant for offender rehabilitation. To research the meaningfulness of both narcissism aspects for forensic offender rehabilitation practice, we systematically reviewed the electronic literature databases CINAHL EBSCOhost, Cochrane CENTRAL, EMBASE, Medline All Ovid, PsycINFO Ovid, and Web of Science Core Collection. Subsequently, we synthesized the outcome into meaningful data classifications related to the risk of violence in offender populations and treatment responsivity. In total, 14 publications on forensic samples were included. Overall, the findings suggest that grandiose narcissism was strongly related to proactive violence and a low treatment responsiveness. Vulnerable narcissism was associated with reactive aggression, mediated by impulsivity and negative emotions, and with a moderate responsivity level. As such, both narcissism aspects seem relevant for the development of structured and focused treatment plans in offender rehabilitation practice. The implications for offender rehabilitation practice are provided.
Hydrogen etch resistance of aluminium oxide passivated graphitic layers
Authors: Kizir Seda , van den Beld Wesley T E , Verbakel Jort D , Pushkarev Roman , Houweling Z Silvester , van de Kruijs Robbert W E , Benschop Jos P H , Bijkerk Fred
Published: August 2021

Graphene inherently possesses defect sites and grain boundaries that are vulnerable to chemical etching by hydrogen radicals. In this study, an etch-mitigation method is presented to selectively passivate these sites using atomic layer deposition (ALD) of a H etch-resistant material. First, as a reference experiment, pristine exfoliated graphitic layers are exposed to H radicals to determine the lateral etch rate from defect sites. Next, these samples are compared to graphitic layers in which the defects are selectively passivated by Al2O3, in the same exposure conditions, using atomic force microscopy at every step in the experiment. The results show that etching is slowed down by local deposition of Al2O3 ALD at sites vulnerable to H radical etching.
Concentration versus absorption for the Vlasov–Navier–Stokes system on bounded domains
Authors: Ertzbischoff Lucas , Han-Kwan Daniel , Moussa Ayman
Published: August 2021

We study the large time behaviour of small data solutions to the Vlasov–Navier–Stokes system set on

Ω
×

R

3

, for a smooth bounded domain Ω of

R

3

, with homogeneous Dirichlet boundary condition for the fluid and absorption boundary condition for the kinetic phase. We prove that the fluid velocity homogenizes to 0 while the distribution function concentrates towards a Dirac mass in velocity centred at 0, with an exponential rate. The proof, which follows the methods introduced in Han-Kwan et al (2020 Arch. Ration. Mech. Anal.
236 1273–323), requires a careful analysis of the boundary effects. We also exhibit examples of classes of initial data leading to a variety of asymptotic behaviours for the kinetic density, from total absorption to no absorption at all.
Experimental study of recombining nitrogen plasmas: II. Electronic population distributions and nonequilibrium radiation of atoms
Authors: Tibère-Inglesse Augustin C , McGuire Sean D , Mariotto Pierre , Laux Christophe O
Published: August 2021

We present optical emission spectroscopy measurements from the vacuum ultraviolet to the near-infrared in a recombining nitrogen plasma flow. An inductively coupled plasma torch is used to create an equilibrium plasma at atmospheric pressure. This plasma is then forced to recombine by flowing through a water-cooled tube. For certain conditions, the plasma is forced out of chemical equilibrium. The emission of excited nitrogen atoms, essential for reentry radiation, is measured to study the nonequilibrium distributions of the electronic states. The densities of the low-lying energy states are found to follow a Boltzmann distribution while the high-lying states are closer to a Saha–Boltzmann distribution—consistent with previous predictions of recombining nonequilibrium plasmas. The measured densities are then compared with the predictions of a two-temperature model, which is found to underpredict the measured densities. The total measured radiation is around 5 orders of magnitude stronger than the equilibrium radiation. The 2-T model estimate of this radiation is much closer yet still underestimates the measured radiation. A model using a single electronic temperature is therefore not sufficient to predict the measurements. The measurements presented in this paper will be useful to test more detailed state-to-state recombination models.
Measurements and analysis of rotational temperatures obtained with Raman and optical emission spectroscopy in a nonequilibrium nitrogen plasma
Authors: Tibère-Inglesse Augustin C , McGuire Sean D , Mariotto Pierre , Laux Christophe O
Published: August 2021

Rotational temperature measurements of N2(B3Πg), N2(C3Πu) and

N

2

+

(

B

2

Σ

u

+

)

obtained by optical emission spectroscopy (OES) are compared with previous gas temperature measurements obtained with Raman spectroscopy in a nonequilibrium recombining nitrogen plasma at atmospheric pressure. The plasma is produced in a state of thermal and chemical equilibrium at about 7000 K using an inductively coupled plasma torch. It is then forced out of chemical equilibrium by imposing rapid cooling through a water-cooled tube. The gas temperature measured by Raman spectroscopy is about 3200 K at the exit of the tube. The rotational temperatures of N2(B) and N2(C) measured with OES are found to be in good agreement with the gas temperature, but the rotational temperature of N2
+(B) is found to be significantly above the gas translational temperature. We propose that this higher rotational temperature is the result of N2
+(B) being formed by the charge exchange reaction between N2(A3Σu
+) and N+. Kinetic and QSS simulations are performed to support this assumption and a rate constant for this reaction is proposed.
Theoretical study of reflection spectroscopy for superconducting quantum parametrons
Authors: Masuda S , Yamaguchi A , Yamaji T , Yamamoto T , Ishikawa T , Matsuzaki Y , Kawabata S
Published: August 2021

Superconducting parametrons in the single-photon Kerr regime, also called KPOs, have been attracting increasing attention in terms of their applications to quantum annealing and universal quantum computation. It is of practical importance to obtain information of superconducting parametrons operating under an oscillating pump field. Spectroscopy can provide information of a superconducting parametron under examination, such as energy level structure, and also useful information for calibration of the pump field. We theoretically study the reflection spectroscopy of superconducting parametrons, and develop a method to obtain the reflection coefficient. We present formulae of the reflection coefficient, the nominal external and the internal decay rates, and examine the obtained spectra. It is shown that the difference of the populations of energy levels manifests itself as a dip or peak in the amplitude of the reflection coefficient, and one can directly extract the coupling strength between the energy levels by measuring the nominal decay rates when the pump field is sufficiently large.
The determination of white dwarf parameters in dwarf novae by optical spectral modeling
Authors: Andreevna Dudnik Anastasiya , Alekseevna Mitrofanova Arina , Vladimirovich Shimansky Vladislav , Vladimirovich Borisov Nikolay , Abdullovich Sakhibullin Nail
Published: August 2021

This paper presents the results of a model analysis of optical spectra and determination of the parameters of three individual SU UMa and WZ Sge type dwarf novae. The moderate resolution spectra of TY Psc, FL Psc and V455 And were obtained at the 6-m BTA of the SAO RAS in the low state of these systems with the determination of white dwarf radiation. The theoretical spectra were calculated using the grid models of hydrogen dwarf atmospheres of white dwarfs by varying the parameters (T
eff and log g) to reach the best agreement with the observed ones. We highlight different effects of the parameters on the shape and intensity of the HI lines. Therefore, it is possible to unambiguously determine T
eff and log g from the analysis of observations. The fundamental parameters of white dwarfs (M and R) were found by comparing the parameters of atmospheres with theoretical models of the internal structure. The obtained parameters of the primaries of TY Psc, FL Psc and V455 And are consistent with the average values for SU UMa and WZ Sge systems. As a result, we demonstrate the efficiency of the method for determining the parameters of such systems based on the analysis of a limited set of observed optical spectra.
A relativistic model of stellar objects with core-crust-envelope division
Authors: Bisht Ravindra K. , Gedela Satyanarayana , Pant Neeraj , Tewari Neeraj
Published: August 2021

In this work, we present a cogent and physically well-behaved solution for neutron stars envisaged with a core layer having quark matter satisfying the MIT-bag equation of state (EoS), meso layer with Bose-Einstein condensate (BEC) matter satisfying modified BEC EoS and an envelope having neutron fluid and Coulomb liquids satisfying quadratic EoS. All the required physical and geometrical parameters like gravitational potentials, pressures, radial velocity, anisotropy, adiabatic index, mass function, compactification factor, and gravitational and surface redshift functions show a feasible trend and are continuous with smooth variation throughout the interior and across the regions of the star. Further, causality condition, energy conditions, static stability criterion (using Tolman-Oppenheimer-Volkoff equation) and Herrera cracking stability criterion are met throughout the star. The approach seems to be resulting in more realistic and accurate modeling of stellar objects, particularly realized by us for X-ray binary stars 4U 1608–52 (M = 1.7 M
⊙, R = 9.5 km) and SAX J1808.4–3658 (M = 1.2 M
⊙, R = 7.2 km). Furthermore, we have ascertained that the continuity of the stability factor in all three regions of the stars demand a smaller core. As the core region of the star increases, the stability factor becomes discontinuous at all the interfaces inside the star.
BGLS-based method of estimating the rotational periods of asteroids
Authors: Ren Yan-Qiong , Lu Xiao-Ping , Liang Yong
Published: August 2021

As the asteroid rotational period is important to the study of the properties of asteroids (e.g., super-fast rotators have structures owing an internal cohesion (rather than being rubble piles bounded by gravity only) so as not to fly apart), constructing an effective and fast method used to search the period attracts much researchers’ attention. Recently, the Bayesian generalized Lomb–Scargle (BGLS) periodogram was developed to improve the convergence efficiency of the Lomb–Scargle method. However, the result of BGLS varies with the frequency range and cannot meet the two minimum/maximum requirements for a complete rotation of the asteroid. We propose a robust BGLS-based method that efficiently determines rotational periods. The proposed method employs a polynomial series to fit folded light curves with potential periods, initially calculated using the BGLS periodogram, and adopts a merit function to estimate and refine best-fit periods. We estimate the rotational periods of 30 asteroids applying the new method to light curves from the Palomar Transient Factory. Results confirm the effectiveness of the BGLS-based method in deriving rotational periods from ground-based observations of asteroids. Further application of the BGLS-based method to sparse light curves, such as Gaia data, is discussed.
Nereid’s orbit based on new precise observations
Authors: Tang Kai , Zhang Hui-Yan , Yu Yong , Yan Dan , Mao Yin-Dun
Published: August 2021

A new orbit of Triton was provided by our previous work, benefitted by new Gaia Data, both in a new precise reduction of charge-coupled device observations and in the planetary ephemeris INPOP19a. In this paper, we provide a new ephemeris for another main Neptunian satellite, Nereid. The orbit is fitted for the newest observations, including 2 075 ground-based observations during the period 1949-2018 and 83 space observations acquired by the Voyager 2 spacecraft in 1989. The dynamical model used here is consistent with that of our previous work. For the ground-based absolute observations of Nereid, the root-mean-square deviations are 0.201″ in right ascension and 0.189″ in declination. Finally, a comparison with the HORIZONS ephemeris is made and discussed.
Power spectral properties of the soft spectral states in four black hole transients
Authors: Mao Dong-Ming , Yu Wen-Fei
Published: August 2021

The X-ray variability in the soft X-ray spectral state of black hole binaries is primarily characterized by a power-law noise (PLN), which is thought to originate from the propagation of the modulation in the mass accretion rate of a standard accretion disk flow. Such a PLN has also been revealed in the disk spectral component in the hard and the intermediate states in several black hole binaries. Here we present an investigation of the Rossi X-ray Timing Explorer (RXTE) observations of four black hole transients in which soft spectral states were observed twenty times or more. We show that in the soft spectral state, the PLN index varied in a large range between –1.64 and –0.62, and the fractional rms variability calculated in the 0.01 – 20 Hz frequency range reached as large as 7.67% and as low as 0.83%. Remarkably, we have found evidence of an inclination dependence of the maximal fractional rms variability, the averaged fractional rms variability and the fractional rms variability of the median in the sample based on current knowledge of inclination of black hole binaries. An inclination dependence has only been predicted in early magnetohydrodynamic simulations of isothermal disks limited to a high-frequency regime. In theory, the noise index is related to the physics of inward propagation of disk fluctuations, while the fractional rms amplitude reflects the intrinsic properties of the magnetohydrodynamic nature of the accretion flow. Our results therefore suggest that X-ray variability in the soft state can be used to put constraints on the properties of the accretion flow as well as the inclination of the accretion disk.
A photometric study of two neglected eclipsing binaries
Authors: Kudak V. , Fedurco M. , Perig V. , Parimucha Š.
Published: August 2021

We present the first BVR photometry, period variation and photometric light curve analysis of two poorly studied eclipsing binaries, V1321 Cyg and CR Tau. Observations were carried out from November 2017 to January 2020 at the observatory of Uzhhorod National University. Period variations were studied using all available early published as well as our minima times. We used the newly developed ELISa code for the light curve analysis and determination of photometric parameters for both systems. We found that V1321 Cyg is a close detached eclipsing system with a low photometric mass ratio of q = 0.28 which suggests that the binary is a post-mass transfer system. No significant period changes in this system are detected. CR Tau is, on the other hand, a semi-detached system where the secondary component almost fills its Roche lobe. We detected a long-term period increase at a rate of 1.49 × 10−7 d yr−1, which supports mass transfer from the lower mass secondary component to the more massive primary.
SETI strategy with FAST fractality
Authors: Chen Yi-Xuan , Liu Wen-Fei , Zhang Zhi-Song , Zhang Tong-Jie
Published: August 2021

We applied the Koch snowflake fractal antenna in planning calibration of the Five-hundred-meter Aperture Spherical radio Telescope (FAST), hypothesizing second-order fractal primary reflectors can optimize the orientated sensitivity of the telescope. Meanwhile, on the grounds of NASA Science Working Group Report in 1984, we reexamine the strategy of Search for Extraterrestrial Intelligence (SETI). A mathematical analysis of the radar equation will be performed in the first section, aiming to make it convenient to design a receiver system that can detect activities of an extraterrestrial civilization, according to the observable region of the narrowband. Taking advantage of the inherent potential of FAST, we simulate the theoretical detection of a Kardashev Type I civilization by a snowflake-selected reflecting area (Drake et al.).
Magneto-acoustic oscillations observed in a solar plage region
Authors: Ji Haisheng , Hashim Parida , Hong Zhenxiang , Xu Zhe , Shen Jinhua , Ji Kaifan , Cao Wenda
Published: August 2021

We gave an extensive study for the quasi-periodic perturbations on the time profiles of the line of sight (LOS) magnetic field in 10 × 10 sub-areas in a solar plage region (corresponds to a facula on the photosphere). The perturbations are found to be associated with the enhancement of He I 10830 Å absorption in a moss region, which is connected to loops with million-degree plasma. FFT analysis to the perturbations gives a kind of spectrum similar to that of Doppler velocity: a number of discrete periods around 5 minutes. The amplitudes of the magnetic perturbations are found to be proportional to magnetic field strength over these sub-areas. In addition, magnetic perturbations lag behind a quarter of the cycle in the phase with respect to the p-mode Doppler velocity. We show that the relationships can be well explained with an MHD solution for the magneto-acoustic oscillations in high-β plasma. Observational analysis also shows that, for the two regions with the stronger and weaker magnetic field, the perturbations are always anti-phased. All findings show that the magnetic perturbations are actually magneto-acoustic oscillations on the solar surface, the photosphere, powered by p-mode oscillations. The findings may provide a new diagnostic tool for exploring the relationship between magneto-acoustic oscillations and the heating of the solar upper atmosphere, as well as their role in helioseismology.
A correction method for the telluric absorptions and application to Lijiang Observatory
Authors: Lu Kai-Xing , Zhang Zhi-Xiang , Huang Ying-Ke , Ren An-Bing , Xu Liang , Feng Hai-Cheng , Xin Yu-Xin , Ding Xu , Yu Xiao-Guang , Bai Jin-Ming
Published: August 2021

Observing a telluric standard star for correcting the telluric absorption lines of spectrum will take a significant amount of precious telescope time, especially in the long-term spectral monitoring project. Beyond that, it is difficult to select a suitable telluric standard star near in both time and airmass to the scientific object. In this paper, we present a method of correcting the telluric absorption lines by combining the advantages of long slit spectroscopy. By rotating the slit, we observed the scientific object and a nearby comparison star in one exposure, so that the spectra of both objects should have the same telluric transmission spectrum. The telluric transmission spectrum was constructed by dividing the observed spectrum of the comparison star by its stellar template, and was used to correct the telluric absorption lines of the scientific object. Using the long slit spectrograph of the Lijiang 2.4-meter telescope, we designed a long-term spectroscopic observation strategy, and finished a four-year spectroscopic monitoring for a pair of objects (an active galactic nucleus and a non-varying comparison star). We applied this method to correct the telluric absorption lines of the long-term monitored spectra by the Lijiang 2.4-meter telescope, and investigated the variation of the telluric absorptions at Lijiang Observatory. We found that the telluric absorption transparency is mainly modulated by the seasonal variability of the relative humidity, airmass and seeing. Using the scatter of the [OIII] λ5007 fluxes emitted from the narrow-line region of active galactic nuclei as an indicator, we found that the correction accuracy of the telluric absorption lines is 1%.
ProteinEvolverABC: coestimation of recombination and substitution rates in protein sequences by approximate Bayesian computation
Authors: Arenas Miguel
Published: August 2021

Motivation

The evolutionary processes of mutation and recombination, upon which selection operates, are fundamental to understand the observed molecular diversity. Unlike nucleotide sequences, the estimation of the recombination rate in protein sequences has been little explored, neither implemented in evolutionary frameworks, despite protein sequencing methods are largely used.

Results

In order to accommodate this need, here I present a computational framework, called ProteinEvolverABC, to jointly estimate recombination and substitution rates from alignments of protein sequences. The framework implements the approximate Bayesian computation approach, with and without regression adjustments and includes a variety of substitution models of protein evolution, demographics and longitudinal sampling. It also implements several nuisance parameters such as heterogeneous amino acid frequencies and rate of change among sites and, proportion of invariable sites. The framework produces accurate coestimation of recombination and substitution rates under diverse evolutionary scenarios. As illustrative examples of usage, I applied it to several viral protein families, including coronaviruses, showing heterogeneous substitution and recombination rates.

Availability and implementation

ProteinEvolverABC is freely available from https://github.com/miguelarenas/proteinevolverabc, includes a graphical user interface for helping the specification of the input settings, extensive documentation and ready-to-use examples. Conveniently, the simulations can run in parallel on multicore machines.

Supplementary information

Supplementary data are available at Bioinformatics online.