bluuebunny/crossref_metadata_2025 huggingface dataset:
A mathematical model of catalyst combination design and temperature control in the preparation of C4 olefins through ethanol coupling
Authors: Tang Pengxiang , Li Hongting , Zhang Xiaomei , Sun Xin
Published: April 2023

The preparation of C4 olefins through ethanol catalytic coupling is a crucial area of study.
Potential role of a novel biphenanthrene derivative isolated from Aerides falcata in central nervous system diseases
Authors: Rivai Bachtiar , Hasriadi  , Dasuni Wasana Peththa Wadu , Chansriniyom Chaisak , Towiwat Pasarapa , Punpreuk Yanyong , Likhitwitayawuid Kittisak , Rojsitthisak Pornchai , Sritularak Boonchoo
Published: April 2023

Central nervous system (CNS) diseases are a significant health burden globally, with the development of novel drugs lagging behind clinical needs.
Visible-light-induced chemo-, diastereo- and enantioselective α-C(sp3)–H functionalization of alkyl silanes
Authors: Feng Lili , Chen Xiaofan , Guo Ning , Zhou Yuqiao , Lin Lili , Cao Weidi , Feng Xiaoming
Published: April 2023

A visible-light-induced chemo-, diastereo- and enantioselective α-C(sp3)–H functionalization of alkyl silanes with benzosultams was realized under a bimetallic synergetic catalysis.
Analytical modelling of high‐frequency losses in toroidal inductors
Authors: Zhao Yuhu , Ming Zhengfeng , Han Binbin
Published: April 2023

Toroidal inductors are widely used in power electronic systems. With the increasing switching frequency of power devices, the AC losses of high‐frequency inductor windings have become an issue that cannot be ignored in design. A method with low computational time cost and high accuracy is urgently needed by designers. This paper proposes a modified analytical method for winding loss calculation of toroidal inductors based on the one‐dimensional Dowell method and the two‐dimensional Ferreira method, and proposes a compensated analytical model considering the proximity effect of inter‐turn conductors of toroidal windings. The analytical method calculates the non‐linear porosity of toroidal windings, and can accurately solve the AC losses of toroidal inductors with arbitrary porosity winding encapsulation. The analytical results are in good agreement with the finite element method (FEM) and experimental data. The experimental measurement data verifies the validity of the proposed model within 1‐MHz frequency, the calculation error of the modified analytical method is less than 25%, and the calculation error of the compensated analytical model is reduced to 10%.
Search for lithium-rich giants in 32 open clusters with high-resolution spectroscopy
Authors: Tsantaki M. , Delgado-Mena E. , Bossini D. , Sousa S. G. , Pancino E. , Martins J. H. C.
Published: April 2023

Context.Lithium-rich giant stars are rare and their existence poses a challenge to our understanding of stellar structure and evolution. In particular, open clusters aptly constrain the mass and age of their members, offering a unique opportunity to understand the evolutionary stage where Li enrichment occurs.

Aims.We take advantage of the high-quality sample gathered for the search for planets in open clusters with HARPS and UVES to look for Li-rich giants and to identify the Li enrichment mechanisms responsible.

Methods.We derived stellar parameters for 247 stars belonging to 32 open clusters, with 0.07 Ga < ages < 3.6 Ga. We employed the spectral synthesis technique code FASMA for the abundance analysis of 228 stars from our sample. We also determined the ages, distances, and extinction using astrometry and photometry fromGaiaand PARSEC isochrones to constrain their evolutionary stage. Our sample covers a wide range of stellar masses from 1 to more than 6M⊙where the majority of the masses are above 2M⊙.

Results.We find 14 canonical Li-rich giant stars that have experienced the first dredge-up. This corresponds to 6% of our total sample, higher than what is typically found for field stars. The majority of the stars (11/14) are located at the red clump, two lie on the red giant branch, and we could not conclude on its evolutionary stage for one. Apart from the canonical limit, we used the maximum Li abundance of the progenitor stars as a criterion for Li enrichment and found 12 Li enriched stars (five appearing in the red clump, five at the upper red giant branch, and two that are inconclusive). We find Li enhancement also among eight stars that have passed the first dredge-up and show strong Li lines based on the fact that stars at the same evolutionary stage in the same cluster have significantly different Li abundances. We confirm that giants with higher Li abundances correspond to a higher fraction of fast-rotating giants, suggesting a connection between Li enhancement and stellar rotation, as predicted by stellar models.

Conclusions.Our Li-rich giants are found in various evolutionary stages, implying that no unique Li production mechanism is responsible for Li enrichment. Instead, there are different intrinsic or external mechanisms that are simultaneously at play.
New constraints on the presence of debris disks around G 196-3 B and VHS J125601.92–125723.9 b
Authors: Zakhozhay Olga V. , Osorio María Rosa Zapatero , Béjar Víctor J. S. , Climent Juan Bautista , Guirado José Carlos , Gauza Bartosz , Lodieu Nicolas , Semenov Dmitry A. , Perez-Torres Miguel , Azulay Rebecca , Rebolo Rafael , Martín-Pintado Jesús , Lefèvre Charlène
Published: April 2023

Context. The existence of warm (protoplanetary) disks around very young isolated planetary and brown dwarf mass objects is known based on near- and mid-infrared flux excesses and millimeter observations. These disks may later evolve into debris disks or rings, although none have been observed or confirmed so far. Little is known about circum(sub)stellar and debris disks around substellar objects.

Aims. We aim to investigate the presence of debris disks around two of the closest (~20 pc), young substellar companions, namely G196-3 B and VHS J125601.92–125723.9 b (VHS J1256–1257 b), whose masses straddle the borderline between planets and brown dwarfs. Both are companions at wide orbits (≥100 au) of M-type dwarfs and their ages (50–100 Myr and 150–300 Myr, respectively) are thought to be adequate for the detection of second-generation disks.

Methods. We obtained deep images of G196-3 B and VHS J1256–1257 b with the NOrthern Extended Millimeter Array (NOEMA) at 1.3 mm. These data were combined with recently published Atacama Large Millimeter Array (ALMA) and Very Large Array (VLA) data of VHS J1256–1257 b at 0.87 mm and 0.9 cm, respectively.

Results. Neither G196-3 B nor VHS J1256–1257 b were detected in the NOEMA, ALMA, and VLA data. At 1.3 mm, we imposed flux upper limits of 0.108 mJy (G196-3 B) and 0.153 mJy (VHS J1256–1257 b) with a 3-σ confidence. Using the flux upper limits at the millimeter and radio wavelength regimes, we derived maximum values of 1.38×10−2 MEarth and 5.46 × 10−3 MEarth for the mass of any cold dust that might be surrounding G196-3 B and VHS J1256–1257 b, respectively.

Conclusions. We put our results in the context of other deep millimeter observations of free-floating and companion objects with substellar masses smaller than 20 MJup and ages between approximately one and a few hundred million years. Only two very young (2–5.4 Myr) objects are detected out of a few tens of them. This implies that the disks around these very low-mass objects must have small masses, and possibly reduced sizes, in agreement with findings by other groups. If debris disks around substellar objects scale down (in mass and size) in a similar manner as protoplanetary disks do, millimeter observations of moderately young brown dwarfs and planets must be at least two orders of magnitude deeper to be able to detect and characterize their surrounding debris disks.
Relevanz der Laser-Flare-Photometrie bei retinalen Pathologien
Authors: Schöneberger Verena , Menghesha Leonie , Feltgen Nicolas , Fuchsluger Thomas Armin , Cursiefen Claus , Schaub Friederike
Published: April 2023

Mithilfe der Laser-Flare-Photometrie kann eine nicht invasive und objektive Messung des Tyndall-Effekts in der Vorderkammer erfolgen. Der Laser-Flare-Wert (Tyndallometrie; gemessen in
Photonenzahl pro Millisekunde [pc/ms]) quantifiziert somit das Ausmaß einer Störung der Blut-Kammerwasser-Schranke und kann dadurch in der klinischen Anwendung zur Überwachung einer
Uveitistherapie oder zum Messen eines postoperativen Entzündungsgrades verwendet werden. Bei der Messung ist eine standardisierte Durchführung zu beachten. Publikationen der letzten 35 Jahre
zur Laser-Flare-Photometrie beschäftigen sich neben dem Messverfahren mit dessen Einsatz in der klinischen Praxis bei unterschiedlichen ophthalmologischen Erkrankungen. Ebenso wurden bereits
verschiedene Einflussfaktoren untersucht und beschrieben, die bei der Messung und Auswertung von Laser-Flare-Werten zu beachten sind. Fokus dieses Beitrags ist die Relevanz der
Laser-Flare-Photometrie in der Retinologie. In kürzlich veröffentlichten Studien zeigt sich die Höhe der objektiven Tyndallometrie bei einer primären rhegmatogenen Amotio abhängig vom
Linsenstatus, der Symptomdauer und dem Ausmaß der Netzhautablösung. Je mehr Fläche der Netzhaut betroffen ist, desto größer scheint die Störung der Blut-Kammerwasser-Schranke. Erhöhte
Laser-Flare-Werte galten zudem bislang als Prädiktor für die Entwicklung einer proliferativen Vitreoretinopathie (PVR), jedoch muss diese Annahme nach aktuellem Kenntnisstand relativiert
werden. Die objektive Tyndallometrie kann nach derzeitiger Datenlage zur Verlaufskontrolle bei intraokularen Entzündungen und zur Quantifizierung der Blut-Kammerwasser-Schranke genutzt
werden. Die Werte korrelieren mit dem Ausmaß und anatomischen Gegebenheiten sowie der Symptomdauer bei Netzhautablösung. Es gibt viele bereits identifizierte Einflussfaktoren, eine weitere
Evaluation ist jedoch wünschenswert und erforderlich. Ob der Laser-Flare-Wert zukünftig als Prädiktor für Folgeerkrankungen wie bspw. die PVR-Entwicklung genutzt werden kann, ist derzeit
noch unklar.
Belastungen erfolgreich meistern – Psychische Schutzfaktoren trainieren
Authors: Kirschner Theresa
Published: April 2023

Immer mehr Klient*innen in zunehmend weniger Zeit behandeln, dazu noch gestresste Kolleg*innen und Katastrophen wie die Pandemie, Kriege und Erdbeben. Viele Therapeut*innen kommen in solchen Zeiten an ihre Belastungsgrenzen. Die Freude sinkt, die emotionale Anspannung steigt. Da hilft nur eins: psychische Schutzfaktoren wie die Resilienz stärken, um mit den Belastungen umgehen zu lernen.
Bedeutsame Betätigungen als Mittel und Ziel – Klientenzentrierung in der pädiatrischen Handtherapie
Authors: Heij Donnée Op
Published: April 2023

Ein klientenzentrierter Therapieansatz ist auch in der pädiatrischen Handtherapie sehr erfolgversprechend. Im Vergleich zur Arbeit mit Erwachsenen gibt es jedoch einige Unterschiede und Besonderheiten. Donnée Op Heij gibt einen Einblick in ihren Berufsalltag und beschreibt, warum es wichtig ist, betätigungsorientierte Assessments einzusetzen und das Umfeld als Ressource zu berücksichtigen.
Forschungsdatenzentrum Gesundheit – Vision für eine
Weiterentwicklung aus Sicht der Forschung
Authors: March Stefanie , Hoffmann Falk , Andrich Silke , Gothe Holger , Icks Andrea , Meyer Ingo , Nimptsch Ulrike , Scholten Nadine , Schulz Mandy , Semler Sebastian Claudius , Stallmann Christoph , Swart Enno , Ihle Peter
Published: April 2023

Das Forschungsdatenzentrum (FDZ) Gesundheit nach der Datentransparenzverordnung
(DaTraV), angesiedelt am Bundesinstitut für Arzneimittel und
Medizinprodukte (BfArM) wird Routinedaten der Gesetzlichen Krankenversicherung
für die Forschung bereitstellen. Die Bereitstellung der Daten von knapp
90% der Bevölkerung in Deutschland dient dem
übergeordneten Ziel, die gesundheitliche Versorgung im Hinblick auf
Unter-, Über- und Fehlversorgung zu evaluieren und daraus
Handlungsempfehlungen für eine evidenzbasierte Gesundheitsversorgung
abzuleiten. Der gesetzliche Rahmen wird im Sozialgesetzbuch (§§
303a-f SBG V) und zwei dazu gehörigen Verordnungen gesteckt,
lässt jedoch hinreichend großen Spielraum für die
Ausgestaltung auf der Organisations- und Arbeitsebene. Hier setzt das
vorliegende Papier an. Aus Forscher*innensicht wurden zehn Statements
für eine Weiterentwicklung formuliert, die das Potential eines
Forschungsdatenzentrums aufzeigen und Ideen für die weitere
zukunftsfähige Ausgestaltung und Entwicklung mit Bestandskraft
darlegen.
Pre-hospital and Hospital Trauma Care during the Covid-19 Lockdown – Experience in a Metropolitan European Level 1 Trauma Centre
Authors: Scherer Julian , Canal Claudio , Kaufmann Ernest , Jensen Kai Oliver , Pape Hans-Christoph , Neuhaus Valentin
Published: April 2023

Background Trauma case load is said to have declined during the Covid-19 pandemic, especially during the national lockdowns. Due to the altered frequency and changes in daily life, pre-hospital care (altered personal protective measurements) as well as mechanisms of trauma and initial trauma treatment may have changed. The purpose of this study was to assess differences in pre-hospital as well as initial treatment of trauma victims and trauma mechanisms during a national lockdown compared to the year before.

Material and Methods Pre-hospital as well as clinical data from all trauma patients admitted to our metropolitan level 1 trauma center resuscitation room during the hard lockdown in Switzerland (March 17 to April 26, 2020) and the same time period in 2019 were analyzed retrospectively.

Results In total, we assessed 91 patients (51 lockdown cohort, 40 control cohort) with a mean age of 50.7 years. Significantly more trauma was sustained in the household environment during the lockdown (p = 0.015). Pre-hospital treatment remained similar between the two assessed groups. No difference was found in length of stay or mortality. In severely injured patients (ISS > 15), we found significantly fewer motor vehicle accidents (p = 0.018) and fewer horizontal decelerations (p = 0.006), but insignificantly more falls (p = 0.092) in the lockdown cohort. None of the patients in the lockdown cohort had a positive PCR test for Covid-19 on admission.

Conclusion Trauma systems seem not to have changed during hard lockdowns in terms of pre-hospital treatment. Fewer severely injured patients due to motor vehicle accidents and horizontal decelerations, but more household-related injuries were seen in the lockdown cohort than in the control cohort. A qualitative analysis of treatment during the hard lockdown is needed to gain further insights into the effect of the pandemic on trauma care.
Bio-evaluation of Untapped Alkaloids from Vinca minor Enriched by Methyl-jasmonate-induced Stress: an Integrated Approach
Authors: El-Senduny Fardous F. , Elgazar Abdullah A. , Alwasify Heba Allah , Abed Alaa , Foda Mohamed , Abouzeid Sara , Lewerenz Laura , Selmar Dirk , Badria Farid
Published: April 2023

The low amount of metabolites isolated from natural products is one of the challenges preventing their biological evaluation. The modulation of biosynthetic pathways by stimulating
stress-induced responses in plants was proven to be a valuable tool for diversification of already known natural products. Recently, we reported the dramatic effect of methyl jasmonate
(MeJA) on Vinca minor alkaloids distribution. In this study, three compounds identified as 9-methoxyvincamine, minovincinine, and minovincine are successfully isolated in good yield
and subjected to several bioassays based on a network pharmacology study. The extracts and isolated compounds show weak to moderate antimicrobial and cytotoxic activities. Also, they are
found to significantly promote wound healing in scratch assay, and transforming growth factor-β (TGF-β) modulation is suggested to be the potential pathway based on
bioinformatic analysis. Hence, Western blotting is used to assess the expression of several markers related to this pathway and wound healing. The extracts and isolated compounds are able to
increase the expression of Smad3 and Phosphatidylinositol-3-kinase (PI3K), while downregulating the levels of cyclin D1 and the mammalian target of rapamycin (mTOR) except for minovincine,
which increases the mTOR expression, inferring that it might act through a different mechanism. Molecular docking is used to give insights on the ability of isolated compounds to bind with
different active sites in mTOR. Collectively, the integrated phytochemical, in silico, and molecular biology approach reveal that V. minor and its metabolite could be
repurposed for the management of dermatological disorders where these markers are dysregulated, which opens the gate to develop new therapeutics in the future.
Boronic Acids and Their Derivatives as Continuous-Flow-Friendly Alkyl Radical Precursors
Authors: Sharma Upendra Kumar , Oliva Monica , Chernobrovkina Viktoriia V. , Van der Eycken Erik V.
Published: April 2023

Since its recognition as an enabling tool to form challenging C–C and C–heteroatom bonds under mild and sustainable conditions, photoredox catalysis has been in the spotlight within the synthetic community. As a consequence, the interest in developing novel synthetic strategies has spiked together with the need to define suitable technologies to overcome scale-up issues dictated by the Bouguer–Beer–Lambert law. In this context, continuous-flow reactors play a major role in increasing the efficiency of a given photocatalyzed reaction, thus rendering scale-up processes more accessible. In the alkyl radical precursor landscape, boron-based species have begun to play a predominant role. Though the reactivity of trifluoroborates has been deeply investigated, the interest in using other boron species as radical precursors in photocatalyzed reactions has recently arisen. This late exploration lies in the fact that the high oxidation potential of boronic acids (BAs) hinders their possible applications. Nevertheless, to circumvent this issue, a diverse array of activation modes has been developed, exploiting in most cases the inherent Lewis acidity of the boronic acid. The aim of this Account is to highlight our recent contribution to this vibrant field with a focus on broad applicability, selectivity, and scalability via continuous-flow methodology. For the sake of clarity, the Account is discussed under the following sections.

1 Introduction

2 Why Photochemistry in Flow?

2.1 Preliminary Considerations

2.2 Batch vs. Flow Photochemical Reactions

2.3 Commercially Available Lab-Scale Solutions for Photoflow Chemistry

3 Organoboron Compounds

3.1 The Evolution of Organoboron Compounds as Radical Precursors in Photoredox Catalysis

3.2 Organoboron Compounds in Flow

4 Activation of Boronic Acids towards Radical Formation

4.1 Giese-Type Addition

4.2 Petasis Reaction

4.3 Light-Driven Four-Component Reaction

4.4 Minisci Reaction

5 Conclusion and Future Perspective
Prospective Comparative Short-Term Study of Autologous Leucocyte-Rich Platelet-Rich Plasma vs. Local Steroids in Chronic Plantar Fascitis
Authors: Sakharkar Nilesh Shravan , Tathe Pankaj Vijay , Jain Prateek , Adewar Aniket N. , Pol Santosh
Published: April 2023

Objectives

Plantar fasciitis is the most common cause of heel pain and is difficult to treat in most chronic and severe forms. Management of plantar fasciitis includes non-surgical options such as non-steroidal anti-inflammatory drugs and corticosteroids, physical therapy, orthotics, and surgical management includes plantar fasciotomy. Local injection of platelet-rich plasma as well as local steroids is an emerging concept in treating recalcitrant tendon and ligament pathology, including plantar fasciitis.

The aim of the study was to evaluate and compare the outcome of patients treated with a single injection of autologous leucocyte-rich platelet-rich plasma with single-injection local steroids triamcinolone in chronic plantar fasciitis.

Material and Methods

The study was conducted for a duration of 24 months. In total, 60 patients with clinically diagnosed chronic plantar fasciitis were selected for study and divided in two groups using the single allocation randomization method as those treated with autologous injection leucocyte-rich platelet-rich plasma and those with injection local steroid triamcinolone and prospectively followed and compared.

Results

Both groups were evaluated subjectively and functionally at primary visit and then on follow-up at 2 weeks, 4 weeks, 8 weeks, and 12 weeks by VAS and hind foot AOFAS score.

Conclusion

We concluded that both injection platelet-rich plasma-treated and injection local steroid-treated patients provide symptomatic relief in the treatment of chronic plantar fasciitis both subjectively and functionally. The steroid treated group showed early symptomatic improvement at 2 weeks, and results at 12 weeks to further follow-up were suggestive that single-injection leucocyte-rich platelet-rich plasma provided better functional results.
Antimicrobial Prescription Pattern in ENT Outpatient Department in a Tertiary Care Teaching Hospital, Telangana, India
Authors: Aalasyam Naveen , Potnuru Shilpa , Sileveru Chandra Mouli , Pokala Uma , P. Naveen
Published: April 2023

Objectives

Otorhinolaryngological infections are very common in adults and in children also. These infections are caused by various microorganisms and to treat these infections, antimicrobial agents are used frequently. As irrational use of antimicrobials leads to the development of antibiotic resistance and it is a big threat to the society, the present study was planned to get awareness among the practitioners regarding the antimicrobial prescription pattern.

To study the prescription pattern of antimicrobial agents in outpatient department of otorhinolaryngology in a tertiary care teaching hospital.

Material and Methods

An observational study was planned over a period of 8 months from July 2019 to February 2020 in ENT outpatient department (OPD) at Mamata General Hospital, Khammam in Telangana. In total, 562 prescriptions were collected. Patient's details, probable diagnosis, prescribed medication details such as generic name, dose, and dosage forms were taken. The collected data was analyzed and the conclusions were drawn using descriptive analysis.

Results

Total number of prescriptions were 562. The majority of the prescriptions belonged to the 21 to 40 years of age group. Males were included more than females (males 320 and females 242). Chronic suppurative otitis media (CSOM) (16.2%) was the commonest infection. Most commonly prescribed antimicrobial was amoxicillin and clavulanic acid combination (26.17%), followed by cefpodoxime with clavulanic acid (21.9%) and ciprofloxacin (19.06%). In 371 (66.01%) prescriptions, only one antimicrobial was prescribed, whereas in 36 (6.40%) prescriptions no antibiotic was given. The average number of drugs per prescription was 3.18 and the average number of antimicrobials per prescription was 1.25. Tablet form (52.9%) was the commonest dosage form and most of the drugs were prescribed by generic name (74.06%).

Conclusion

The present study though prescription pattern of antibiotics and adherence to the hospital formulary by the physicians in the hospital is encouraging, still there is a chance in reducing the number of drugs prescribed per patient. The findings of this study will be useful to prescribe antimicrobials rationally so that the patient and health care system on the whole will be benefited.
Clinical and Radiological Results of Minimally Invasive Two-Hole Dynamic Hip Screw Fixation of Stable Intertrochanteric Fractures: A Prospective Study of 50 Patients
Authors: Dar Fiaz Ahmad , Iqbal Zaffar , Lone Ansarul Haq , Ali Nadeem
Published: April 2023

Objectives

Intertrochanteric fractures are fractures of elderly population and are known for morbidity and mortality. Early stabilization with minimal surgical trauma is important for early mobilization to prevent recumbence-related complications.

Material and Methods

This prospective study was conducted on 50 stable intertrochanteric fractures that were managed by fixation with a small two-hole dynamic hip screw –(DHS) side plate using a minimally invasive technique. The surgical time, intraoperative blood loss, length of the skin incision, duration of hospital stay, time to full weight bearing and fracture union, and complications were recorded.

Results

The mean age of the patients was 60.2 years with 64% belonging to male sex. The mean operative time, average blood loss, and mean incision length were 35.6 minutes, 68.4 mL, and 3.7 cm, respectively. Time to bone healing ranged from 10 to 16 weeks (mean 13 weeks). Two patients had hip screw backout but that did not interfere with failure of fixation.

Conclusion

Stabilization of stable intertrochanteric fractures with two-hole DHS using minimally invasive approach is a viable option with negligible complication rate related to failure of small DHS side plate.
Iatrogenic Injuries Related to Thermal Ablation of the Liver and Pancreas
Authors: HonShideler Curtis , Lin Liz , HonShideler Kelsey , Guez David , Bader Mohammad
Published: April 2023

Thermal ablation is a widely utilized treatment option for tumors of the liver and pancreas; procedures may be performed intraoperatively or percutaneously, under image guidance (more recently, endoscopy-guided ablation of pancreatic tumors has also been introduced). Through differing mechanisms, radiofrequency ablation, microwave ablation, and cryoablation aim to precisely eradicate tumor, with adequate margins and minimal injury to normal surrounding tissue. Knowledge of thermal ablative risks and complications is crucial for both therapeutic planning and postprocedural management to optimize outcomes and avoid significant patient injury. In this review, we discuss iatrogenic injuries related to thermal ablation of hepatic and pancreatic malignancies.
The Emerging Spectrum of Respiratory Diseases in the U.S. Cannabis Industry
Authors: Sack Coralynn , Simpson Christopher , Pacheco Karin
Published: April 2023

While the cannabis industry is one of the fastest growing job markets in the United States and globally, relatively little is known about the occupational hazards that cannabis production workers face. Based on the closely related hemp industry and preliminary studies from recreational cannabis grow facilities, there is concern for significant respiratory exposures to bioaerosols containing microbial and plant allergens, chemicals such as pesticides, volatile organic compounds, and other irritant gases. Components of the cannabis plant have also recently been identified as allergenic and capable of inducing an immunoglobulin E-mediated response. Accumulating evidence indicates a spectrum of work-related respiratory diseases, particularly asthma and other allergic diseases. Disentangling causal relationships is difficult given the heterogeneity of mixed exposures, diagnostic challenges, and confounding by personal cannabis use. Despite and because of these uncertainties, better regulatory guidance and exposure controls need to be defined in order to reduce the risk of work-related disease.
The Bush Doctrine redux: changes and continuities in American grand strategy since ‘9/11’
Authors: Löfflmann Georg
Published: April 2023

This article examines the ideational dimension and political performance of American grand strategy since ‘9/11’ and explores to what extent the strategic assumptions, ideological dispositions, and security practices of the Bush Doctrine have endured since the 2001 terrorist attacks. It advances a constructivist understanding of American grand strategy as a nexus of national identity discourses and security practices. The article will first explore the significance of American exceptionalism in the ideational dimension of the Bush Doctrine and its practical impact in the pursuit of US national security. The article will then focus on the Obama Doctrine, arguing that its embrace of cooperative engagement and multilateralism represented a limited strategic course correction within the paradigm of liberal hegemony. Finally, the article will contrast grand strategy discourses under Bush and Donald Trump, exploring their shared foundations in Jacksonian nationalism and unilateralism that demonstrate the continued relevance of Bush’s strategic vision of US primacy.
On the impact of electric field fluctuations on microtearing turbulence
Authors: Hamed M. , Pueschel M. J. , Citrin J. , Muraglia M. , Garbet X. , Camenen Y.
Published: April 2023

The magnetic drift and the electric potential play an important role in microtearing destabilization by increasing the growth rate of this instability in the presence of collisions, while in electrostatic plasma micro-turbulence, zonal electric potentials can have a strong impact on turbulent saturation. A reduced model has been developed, showing that the Rechester–Rosenbluth model is a good model for the prediction of electron heat diffusivity by microtearing turbulence. Here, nonlinear gyrokinetic flux-tube simulations are performed in order to compute the characteristics of microtearing turbulence and the associated heat fluxes in tokamak plasmas and to assess how zonal flows and zonal fields affect saturation. This is consistent with a change in saturation mechanism from temperature corrugations to zonal field- and zonal flow-based energy transfer. It is found that removing the electrostatic potential causes a flux increase, while linearly stabilization is observed.
Octahedral to tetrahedral bonding transitions in the local structure of phase change optical media Ge2Sb2Se5xTe5−5x with Se doping
Authors: Xu Zhenyang , Restrepo Francisco , Zhao Junjing , Chatterjee Utpal , Louca Despina
Published: April 2023

Random access memories utilize fast, reversible switching between ordered and disordered states of matter in phase change materials (PCMs) such as Ge2Sb2Te5−5x. The short-range structure in the disordered phase has been described either as (i) a network of Ge tetrahedra or (ii) Peierls distorted Ge/Sb octahedra. The PCM transition was investigated in bulk Ge2Sb2Se5xTe5−5x (GSST), in which amorphization sets in with Se doping (x ≈ 0.85) upon quenching. GSST has a hexagonal crystalline ground state with Ge/Sb octahedral coordination, but the phase change transition to the amorphous state that is only observed when the system is quenched brings a short-range structure with sharp, tetrahedrally coordinated Ge/Sb correlations and shortened bonds that are distinctly different from the expected octahedral pairing.
Automatic identification of edge localized modes in the DIII-D tokamak
Authors: O’Shea Finn H. , Joung Semin , Smith David R. , Coffee Ryan
Published: April 2023

Fusion power production in tokamaks uses discharge configurations that risk producing strong type I edge localized modes. The largest of these modes will likely increase impurities in the plasma and potentially damage plasma facing components, such as the protective heat and particle divertor. Machine learning-based prediction and control may provide for the automatic detection and mitigation of these damaging modes before they grow too large to suppress. To that end, large labeled datasets are required for the supervised training of machine learning models. We present an algorithm that achieves 97.7% precision when automatically labeling edge localized modes in the large DIII-D tokamak discharge database. The algorithm has no user controlled parameters and is largely robust to tokamak and plasma configuration changes. This automatically labeled database of events can subsequently feed future training of machine learning models aimed at autonomous edge localized mode control and suppression.
Constant chemical potential–quantum mechanical–molecular dynamics simulations of the graphene–electrolyte double layer
Authors: Di Pasquale Nicodemo , Finney Aaron R. , Elliott Joshua D. , Carbone Paola , Salvalaglio Matteo
Published: April 2023

We present the coupling of two frameworks—the pseudo-open boundary simulation method known as constant potential molecular dynamics simulations (CμMD), combined with quantum mechanics/molecular dynamics (QMMD) calculations—to describe the properties of graphene electrodes in contact with electrolytes. The resulting CμQMMD model was then applied to three ionic solutions (LiCl, NaCl, and KCl in water) at bulk solution concentrations ranging from 0.5 M to 6 M in contact with a charged graphene electrode. The new approach we are describing here provides a simulation protocol to control the concentration of electrolyte solutions while including the effects of a fully polarizable electrode surface. Thanks to this coupling, we are able to accurately model both the electrode and solution side of the double layer and provide a thorough analysis of the properties of electrolytes at charged interfaces, such as the screening ability of the electrolyte and the electrostatic potential profile. We also report the calculation of the integral electrochemical double layer capacitance in the whole range of concentrations analyzed for each ionic species, while the quantum mechanical simulations provide access to the differential and integral quantum capacitance. We highlight how subtle features, such as the adsorption of potassium graphene or the tendency of the ions to form clusters contribute to the ability of graphene to store charge, and suggest implications for desalination.
A self-powered MXene/InGaN van der Waals heterojunction mini-photodetector for visible light communication
Authors: Kong Deqi , Lin Tingting , Chai Jixing , Zhu Zihe , Liu Peixin , Lin Zhengliang , Lin Tingjun , Li Linhao , Chen Liang , Li Guoqiang , Wang Wenliang
Published: April 2023

A van der Waals heterojunction-based photodetector has attracted significant interest due to its potential for high-speed visible light communication (VLC) application. Herein, we report a self-powered and high-performance MXene/InGaN van der Waals heterojunction visible light mini-photodetector (mini-PD). The combination of MXene and InGaN creates a Schottky junction that effectively separates the photoinduced electron/hole pairs, resulting in a robust heterojunction structure while enhancing carrier mobility and lifetime. The mini-PD exhibits the responsivity of 6.0 A/W, a specific detection rate of 9 × 1011 Jones, and rise/decay times of 7.1/183.2 μs under 470 nm blue light (36.5 μW/cm2) without bias voltage. The results show that MXene forms a robust type-II band arrangement with InGaN, which converts the optical signal into a large electrical signal and improves the stability of the mini-PD. This work provides a strategy for high-speed VLC without external energy input that has great potential for applications such as energy-efficient communication, sensor networks, and low-sensitivity detection.
Hybrid ablation–expansion model for laser interaction with low-density foams
Authors: Hudec L. , Gintrand A. , Limpouch J. , Liska R. , Shekhanov S. , Tikhonchuk V. T. , Weber S.
Published: April 2023

A sub-grid foam model is developed to describe numerically a sequence of processes transforming solid elements in the foam into a hot plasma under the energy deposition by lasers. We account for three distinct processes: accurate laser energy absorption and scattering on the sub-wavelength cylindrical solid elements, expansion of the foam element due to the energy deposition in its volume, and ablation of the solid element due to the energy deposition on its surface. The foam element dynamics is modeled via a self-similar isothermal expansion combined with a stationary ablation model, and it is described by a set of ordinary differential equations. The microscopic single pore model is incorporated in the macroscopic hydrodynamic codes, and numerical simulations show a good agreement with available experimental data.
Sensitivity of synchrotron radiation to the superthermal electron population in mildly relativistic plasma
Authors: Mlodik M. E. , Munirov V. R. , Rubin T. , Fisch N. J.
Published: April 2023

Synchrotron radiation has markedly different behavior in ∼ 10     keV and in ∼ 100     keV plasma. We show that high-energy electrons that occupy the tail of velocity distribution function have disproportionate impact on power loss of ∼ 100     keV plasma. If electrons with energy more than cutoff energy are redistributed while keeping the Maxwellian distribution function below cutoff energy intact, both emission and absorption of synchrotron radiation act to decrease the lost power. These novel radiation transport effects in non-equilibrium plasma suggest large utility in the deconfinement of high-energy electrons to reduce synchrotron radiation in applications where the radiation is deleterious.
Laminar separation bubble on a rotating cylinder in uniform flow
Authors: Chopra Gaurav , Mittal Sanjay
Published: April 2023

We study the effect of spin ( 0 ≤ α ≤ 2) of a cylinder, placed in uniform flow, on the transition of the boundary layer. Large Eddy Simulation, with the Sigma turbulence model to account for the sub-grid scales, is carried out using a stabilized finite element formulation. The Reynolds numbers ( R e = 0.6 × 10 5 and 1.0 × 10 5) lie in the high-subcritical regime for a non-rotating cylinder where the boundary layer separates in a laminar state and does not reattach. Magnus effect is observed at low α wherein separation is delayed on the retreating side and preponed on the advancing side, resulting in a lift force that increases with increase in α. At a certain critical α, the boundary layer on the advancing side transitions to a turbulent state, causing it to reattach. A laminar separation bubble (LSB) forms, significantly delaying the final separation and increasing suction. At R e = 1.0 × 10 5, this suction overcomes that on the retreating side, leading to a reversal in the direction of lift force, referred to as the inverse Magnus effect. The LSB is accompanied by weakened vortex shedding at increased frequency. The spatial extent of the LSB and the magnitude of reverse lift, at a given Re, decreases with increase in α. The lift force changes direction yet again at a certain α marking the end of the inverse Magnus effect regime and beginning of the second Magnus effect regime. The LSB vanishes beyond a certain spin rate, and the boundary layer directly transitions to a turbulent state.
Ideal MHD induced temperature flattening in spherical tokamaks
Authors: Jardin S. C. , Ferraro N. M. , Guttenfelder W. , Kaye S. M. , Munaretto S.
Published: April 2023

This paper extends the analysis first presented in Jardin et al. [Phys. Rev. Lett. 128, 245001 (2022)] to more thoroughly examine the stability of spherical torus equilibrium to ideal magnetohydrodynamic (MHD) infernal modes and their nonlinear consequences. We demonstrate that in a 3D resistive magnetohydrodynamic (MHD) simulation of a NSTX discharge, anomalous transport can occur due to these instabilities. We generate a family of equilibrium of differing β and use this to show that these instabilities could explain the experimentally observed flattening of the electron temperature profile at modest β. The modes studied in this paper are found to occur with poloidal mode number m and toroidal mode number n when the ratio m/n is in the range of 1.2–1.5, when the central safety factor is in this range or slightly lower, and when the central region has very low magnetic shear. Our analysis gives some insight as to why the unstable linear growth rates are oscillatory functions of the toroidal mode number n. We present a simulation of an initially stable configuration that passes through a stability boundary at a critical β as it is heated. We also show that a particular NSTX discharge is unstable to these modes over a timescale of several hundred ms. We conclude that these modes must be taken into account when performing predictive modeling. An appendix shows that similar modes can be found in R / a = 4 tokamaks for certain q-profiles and β values.
K-space interpretation of image-scanning-microscopy
Authors: Sommer Tal I. , Weinberg Gil , Katz Ori
Published: April 2023

In recent years, image-scanning microscopy (ISM, also termed pixel-reassignment microscopy) has emerged as a technique that improves the resolution and signal-to-noise compared to confocal and widefield microscopy by employing a detector array at the image plane of a confocal laser scanning microscope. Here, we present a k-space analysis of coherent ISM, showing that ISM is equivalent to spotlight synthetic-aperture radar and analogous to oblique-illumination microscopy. This insight indicates that ISM can be performed with a single detector placed in the k-space of the sample, which we numerically demonstrate.
Modeling of dispersion of aerosolized airborne pathogens exhaled in indoor spaces
Authors: Sharma Praveen , Bahga Supreet Singh , Gupta Amit
Published: April 2023

Since the beginning of the COVID19 pandemic, there has been a lack of data to quantify the role played by breathing-out of pathogens in the spread of SARS-Cov-2 despite sufficient indication of its culpability. This work aims to establish the role of aerosol dispersion of SARS-Cov-2 virus and similar airborne pathogens on the spread of the disease in enclosed spaces. A steady-state fluid solver is used to simulate the air flow field, which is then used to compute the dispersion of SARS-Cov-2 and spatial probability distribution of infection inside two representative classrooms. In particular, the dependence of the turbulent diffusivity of the passive scalar on the air changes per hour and the number of inlet ducts has been given due consideration. By mimicking the presence of several humans in an enclosed space with a time-periodic inhalation–exhalation cycle, this study firmly establishes breathing as a major contributor in the spread of the pathogen, especially by superspreaders. Second, a spatial gradient of pathogen concentration is established inside the domain, which strongly refutes the well-mixed theory. Furthermore, higher ventilation rates and proximity of the infected person to the inlet and exhaust vents play an important role in determining the spread of the pathogen. In the case of classrooms, a ventilation rate equivalent to 9 air changes or more is recommended. The simulations show that the “one-meter distance rule” between the occupants can significantly reduce the risk of spreading infection by a high-emitter.
Sex, ducks, and rock “n” roll: Mathematical model of sexual response
Authors: Blyuss K. B. , Kyrychko Y. N.
Published: April 2023

In this paper, we derive and analyze a mathematical model of a sexual response. As a starting point, we discuss two studies that proposed a connection between a sexual response cycle and a cusp catastrophe and explain why that connection is incorrect but suggests an analogy with excitable systems. This then serves as a basis for derivation of a phenomenological mathematical model of a sexual response, in which the variables represent levels of physiological and psychological arousal. Bifurcation analysis is performed to identify stability properties of the model’s steady state, and numerical simulations are performed to illustrate different types of behavior that can be observed in the model. Solutions corresponding to the dynamics associated with the Masters–Johnson sexual response cycle are represented by “canard”-like trajectories that follow an unstable slow manifold before making a large excursion in the phase space. We also consider a stochastic version of the model, for which spectrum, variance, and coherence of stochastic oscillations around a deterministically stable steady state are found analytically, and confidence regions are computed. Large deviation theory is used to explore the possibility of stochastic escape from the neighborhood of the deterministically stable steady state, and the methods of an action plot and quasi-potential are employed to compute most probable escape paths. We discuss implications of the results for facilitating better quantitative understanding of the dynamics of a human sexual response and for improving clinical practice.
Monolithic
β
-Ga2O3 NMOS IC based on heteroepitaxial E-mode MOSFETs
Authors: Khandelwal Vishal , Yuvaraja Saravanan , García Glen Isaac Maciel , Wang Chuanju , Lu Yi , AlQatari Feras , Li Xiaohang
Published: April 2023

In this Letter, we report on a monolithically integrated β-Ga2O3 NMOS inverter integrated circuit (IC) based on heteroepitaxial enhancement mode (E-mode) β-Ga2O3 metal-oxide-semiconductor field-effect transistors on low-cost sapphire substrates. A gate recess technique was employed to deplete the channel for E-mode operation. The E-mode devices showed an on-off ratio of ∼105 with a threshold voltage of 3 V. In comparison, control devices without the gate recess exhibited a depletion mode (D-mode) with a threshold voltage of −3.8 V. Furthermore, depletion-load NMOS inverter ICs were fabricated by monolithically integrating D- and E-mode transistors on the same substrate. These NMOS ICs demonstrated inverter logic operation with a voltage gain of 2.5 at VDD = 9 V, comparable with recent GaN and other wide-bandgap semiconductor-based inverters. This work lays the foundation for heteroepitaxial low-cost and scalable β-Ga2O3 ICs for monolithic integration with (ultra)wide bandgap Ga2O3 power devices.
Deformations of an active liquid droplet
Authors: Kree R. , Zippelius A.
Published: April 2023

A fluid droplet, in general, deforms if subject to active driving, such as a finite slip velocity or active tractions on its interface. Starting from Stokes equations, we show that these deformations and their dynamics can be computed analytically in a perturbation theory in the inverse of the surface tension γ, by using an approach based on vector spherical harmonics. We consider squirmer models and general active tractions, such as inhomogeneous surface tensions, which may result from the Marangoni effects. In the lowest order, the deformation is of order ε∝1/γ, yet it affects the flow fields inside and outside of the droplet in order to ε0. Hence, a correct description of the flow has to allow for shape fluctuations, —even in the limit of large surface tension. We compute stationary shapes and relaxation times and compare our results to an approach, which discards all effects of deformations on surface tensions. This approach leads to the same propulsion velocity but to significantly different flow fields.
Understanding stable/unstable miscible A+B→C reaction front and mixing in porous medium
Authors: Verma Priya , Sharma Vandita , Mishra Manoranjan
Published: April 2023

The transport phenomena of A + B → C type reactive miscible front undergoing radial displacement in a porous medium are numerically investigated. For a stable displacement when the viscosity of fluids A, B, and C is same, the dependence of various reaction characteristics on the Damköhler number (Da) is analyzed. The total reaction rate is found to be a non-monotonic function of time depending upon Da, while the total amount of product follows the temporal scaling ∝ t f ( D a ). The viscosity contrast in the system renders unstable flow and results in a hydrodynamic instability called viscous fingering. The effect of hydrodynamics on the reaction product formation is discussed. An insight into the reaction characteristics due to interaction of chemical reaction and instability is obtained for various log-mobility ratios R b   and   R c. It is observed that the onset of instability, as well as the mixing of the fluids, depends on whether the reaction generates a high or less viscous product or equivalently, the sign of | R b − R c |, keeping Rb fixed. Furthermore, the relation between the first moment of averaged reaction rate for stable and unstable displacement is influenced by the sign of | R b − R c | and Da. The coupling of convection and diffusion on the chemo-hydrodynamic instability is presented, and the existence of the frozen fingers in this reactive fluid system is reported. Our numerical results allow us to understand how instability and chemical reaction interplay to affect the reaction characteristics and the mixing of fluids.
From a single dust grain to basic thermodynamics
Authors: Block Dietmar , Wohlfahrt Sören , Wieben Frank
Published: April 2023

This contribution summarizes recent experiments in dusty plasmas and puts their results into context. The aim is to discuss the fundamental question whether a dusty plasma can be regarded as a model system for strong coupling and whether the treatment as a one-component plasma is a good and valid approximation.