bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterobimetallic Au(i)/Y(iii) single chain nanoparticles as recyclable homogenous catalysts
Authors: Bohlen Josina L. , Kulendran Bragavie , Rothfuss Hannah , Barner-Kowollik Christopher , Roesky Peter W.
Published: June 2021

Au(i)/Y(iii) single chain nanoparticles (SCNPs) are potent homogenous, recyclable catalysts for the hydroamination. The SCNPs consist of terpolymer chains with orthogonal ligand units, enabling the selective embedding of different metals.
Programmed topographical features generated on command in confined electroactive films
Authors: Visschers Fabian L. L. , Broer Dirk J. , Liu Danqing
Published: June 2021

This work describes a method to create dynamic pre-programmed surface textures by an alternating electric field on coatings that consist of a silicon oxide reinforced viscoelastic siloxane network.
The corona – chromosphere connection studied with simultaneous eROSITA and TIGRE observations
Authors: Fuhrmeister B. , Czesla S. , Robrade J. , González-Pérez J. N. , Schneider C. , Mittag M. , Schmitt J. H. M. M.
Published: June 2021

Stellar activity manifests itself in a variety of different phenomena, some of which we can measure as activity tracers from different atmospheric layers of the star, typically at different wavelengths. Stellar activity is furthermore inherently time variable, therefore simultaneous measurements are necessary to study the correlation between different activity indicators. In this study we compare X-ray fluxes measured within the first all-sky survey conducted by the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) instrument on board the Spectrum-Roentgen-Gamma observatory to Ca II H&K excess flux measurements RHK+, using observations made with the robotic TIGRE telescope. We created the largest sample of simultaneous X-ray and spectroscopic Ca II H&K observations of late-type stars obtained so far, and in addition, previous measurements of Ca II H&K for all sample stars were obtained. We find the expected correlation between our log(LX/Lbol) to log(RHK+) measurements, but when the whole stellar ensemble is considered, the correlation between coronal and chromospheric activity indicators does not improve when the simultaneously measured data are used. A more detailed analysis shows that the correlation of log(LX/Lbol) to log(RHK+) measurements of the pseudo-simultaneous data still has a high probability of being better than that of a random set of non-simultaneous measurements with a long time baseline between the observations. Cyclic variations on longer timescales are therefore far more important for the activity flux-flux relations than short-term variations in the form of rotational modulation or flares, regarding the addition of “noise” to the activity flux-flux correlations. Finally, regarding the question of predictability of necessarily space-based log (LX/Lbol) measurements by using ground-based chromospheric indices, we present a relation for estimating log (LX/Lbol) from RHK+ values and show that the expected error in the calculated minus observed (C-O) log (LX/Lbol) values is 0.35 dex.
Dynamics of nanodust in the vicinity of a stellar corona: Effect of plasma corotation
Authors: Czechowski A. , Mann I.
Published: June 2021

Context. In the vicinity of the Sun or other stars, the motion of the coronal and stellar wind plasma must include some amount of corotation, which could affect the dynamics of charged dust particles. In the case of the Sun, this region is now investigated in situ by the Parker Solar Probe. Charged dust particles coming from the vicinity of the Sun can also reach, and possibly be detected by, the Solar Orbiter.

Aims. We use numerical simulations and theoretical models to study the effect of plasma corotation on the motion of charged nanodust particles released from the parent bodies moving in Keplerian orbits, with particular attention to the case of trapped particles.

Methods. We used two methods: the motion of nanodust is described either by numerical solutions of full equations of motion, or by a two-dimensional (distance vs. radial velocity) model based on the guiding centre approximation. The models of the plasma and magnetic field in the vicinity of the star are based on analytical solutions that satisfy the freezing-in equations.

Results. Including plasma corotation does not prevent trapping of nanodust in the vicinity of the Sun or other stars. This result can be understood with the help of the model based on the guiding centre approximation. For the amount of corotation expected near the Sun, the outer limit of the trapped region is almost unaffected. If the corotation persists outside the trapping region, the speed of particles ejected from the Sun is moderately increased. A strong effect of plasma corotation on charged particle dynamics occurs for the star with a high rotation rate and/or a low value of the stellar wind speed.
Noble liquid calorimetry at the LHC and prospects of its application in future collider experiments
Authors: Aleksa Martin
Published: June 2021

Calorimetry is an important measurement technique in experimental particle physics. Although calorimeters based on liquefied noble gases were first proposed 50 years ago, they continue to play an important role in modern particle physics and have substantially contributed to the discovery of the Higgs boson at the Large Hadron Collider (LHC) at CERN in 2012.
Another hitchhiker exposed: Diceratocephala boschmai (Platyhelminthes: Temnocephalida) found associated with ornamental crayfish Cherax spp.
Authors: Ložek Filip , Patoka Jiří , Bláha Martin
Published: June 2021

There are known plenty tiny invertebrate species associated with decapod crustaceans. Our contribution documents the first record of New Guinean ornamental Cherax crayfish epibiont, Diceratocephala boschmai (Platyhelminthes: Temnocephalida) found in pet trade in the Czech Republic. Correct species assignment was confirmed by genetic barcoding. The pathway for introductions of organisms unintentionally moved in association with ornamental crayfish via the international trade has been highlighted. Although Cherax species survive in thermal waters in Europe, even potential introduction to these habitats posed threat to native crayfish ectosymbionts (branchiobdellids) thought similar ecological niche.
Évolution des usages contraceptifs
Authors: Le Guen Mireille
Published: June 2021

Il est difficile de dire avec précision depuis quand les êtres humains ont souhaité contrôler leur fécondité, tant cette pratique paraît ancienne. Toutefois, on observe au fil du temps deux évolutions majeures. Au cours desxviiieetxixesiècles en Europe, la « première révolution contraceptive » se caractérise par l’adoption du « retrait » au sein des couples mariés. Quant à la « seconde révolution contraceptive », elle n’intervient qu’à partir de la seconde moitié duxxesiècle, avec la diffusion progressive de la pilule et du dispositif intra-utérin (DIU) au sein des différents groupes sociaux. Depuis lors, les pratiques contraceptives sont largement médicalisées et le contrôle de la fécondité est devenue une responsabilité exclusivement féminine.
IAP et cancer : le NO contre-attaque
Authors: Guérin Eva , Meunier Mélina , Plenchette Stéphanie
Published: June 2021

Dans le cadre du Master 2 de l’université EPHE-PSL (Master Sciences du vivant, cursus IMaGHE, parcours Physiopathologie intégrative [PPI]), des étudiants se sont confrontés à la rédaction d’une nouvelle scientifique. Ces étudiants ayant choisi une spécialisation en cancérologie, l’équipe pédagogique leur a proposé de faire une synthèse d’articles sur deux thématiques : 1) les protéines IAP et un mécanisme original de régulation de leur activité par S-nitrosylation et 2) la séparase, dont un article paru récemment dans Nature montre qu’elle jouerait un rôle inattendu dans la protection des cellules contre la transformation tumorale. Organisés en binôme ou trinôme, les étudiants ont rédigé deux nouvelles qui soulignent l’intérêt des travaux analysés, ainsi que leur originalité. Ils se sont pleinement investis dans cette tâche et ont su faire preuve d’un bel esprit de synthèse. Ils ont apprécié cet exercice nouveau pour eux, mais qui leur a permis d’avoir un aperçu de la publication scientifique inhérente au métier de chercheur auquel ils se destinent.
La mucoviscidose
Authors: Férec Claude
Published: June 2021

La mucoviscidose est, aujourd’hui, une maladie devenue chronique chez l’adulte. Les progrès dans la connaissance de la physiopathologie de cette maladie, de sa prise en charge, de l’organisation des soins, du diagnostic, et de la thérapeutie, sont à mettre au crédit de la découverte en 1989 du gène responsable de cette maladie, le gène CFTR (cystic fibrosis transmembrane conductance regulator). Cette découverte a ouvert un champ, jusqu’alors inexploré, d’études du spectre des mutations de ce gène et de l’impact de ces dernières sur la fonction de la protéine, apportant un nouvel éclairage sur les relations entre génotype et phénotype. La découverte de molécules modulatrices agissant sur la protéine CFTR a enrichi considérablement notre arsenal thérapeutique. Elle illustre l’un des succès de la médecine dite de précision.
La photonique en Allemagne
Authors: Raspa Antonio
Published: June 2021

La forte croissance mondiale de la photonique au cours de la dernière décennie n'est nulle part mieux illustrée qu'en Allemagne. Selon Max Milbredt, de Germany Trade & Invest, l'Allemagne est la première nation photonique d'Europe, employant près de 142 500 personnes et représentant un peu plus de 41 % de la production du continent.
ω-3-Fettsäuren – gesundheitliche Effekte und Diagnose des Mangels
Authors: von Schacky Prof. Dr. med. Clemens
Published: June 2021

Ein Mangel an ω-3-Fettsäuren ist weltweit verbreitet. Ursache sind u. a. ein zu geringer Fischverzehr sowie rückläufige Gehalte von Eicosapentaensäure (EPA) und Docosahexaensäure (DHA) in Zuchtlachs. Es deutet sich an, dass die Mortalität an COVID-19 durch die Gabe von EPA und DHA reduziert werden kann. Zudem können diese Fettsäuren den mit der Alterung verbundenen Abbau von Muskeln und Gehirn verlangsamen und sich günstig auf Entzündungen auswirken. Über die Bestimmung des Versorgungsstatus mit ω-3-Fettsäuren und die Effekte der maritimen Fettsäuren sprach Herausgeber Uwe Gröber mit Professor Dr. Clemens von Schacky.
Management of Leukemia and Partial Atrioventricular Septal Defect during Pregnancy
Authors: Li Zhi , Sun Haoliang , Li Jinghang , Zhu Yu
Published: June 2021

Background Pregnancy-associated acute myeloid leukemia (PA-AML) is rare. Cardiac surgery in the context of AML poses challenges that are seldom encountered.

Case Description The subject is a 31-year-old woman at 38 weeks' gestational age diagnosed with AML and partial atrioventricular septal defect. After multidisciplinary consulting, an urgent cesarean section was performed, then chemotherapy was initiated, followed by minimally invasive cardiac surgery with an uneventful recovery.

Conclusion Efficient multidisciplinary approach is essential in the management of PA-AML and cardiac disease. Minimally invasive cardiac surgery may be safe and useful in patients with AML.
Biomedical Waste and Solid Waste Management in the Time of COVID-19: A Comprehensive Review of the National and International Scenario and Guidelines
Authors: Capoor Malini R. , Parida Annapurna
Published: June 2021

Biomedical waste generated during the diagnosis, isolation, and treatment of coronavirus disease 2019 (COVID-19) patients can also be the source of new infections; hence, it needs special consideration. Previous guidelines for the management of biomedical waste need to be revisited as the majority of COVID-19 patients remain asymptomatic and reside in community. Personal protective equipment (PPE) like masks, hazmat suits, gloves, and visors are now being used by the public also. Thus, the general household waste and disposables now make an exponential increase in the waste that can be considered an environmental hazard. In this article, the authors have tried to present the problems arising from COVID-19 waste and the recommendations put forth by competent authorities both nationally and internationally on COVID-19 waste management. Furthermore, in all the guidelines, it is crucial that the COVID-19 waste management follows environmentally sound principles and practices of biomedical waste management, with safe work and infection-control practices. Segregation of COVID-19 waste at source, awareness, and precautions at all steps of the waste-cycle are the only way ahead in this crisis.
Lipschütz Ulcer: An Unusual Diagnosis that Should Not be Neglected
Authors: Pereira Daniela Alexandra Gonçalves , Teixeira Eliana Patrícia Pereira , Lopes Ana Cláudia Martins , Sarmento Ricardo José Pina , Lopes Ana Paula Calado
Published: June 2021

The diagnosis of genital ulcers remains a challenge in clinical practice. Lipschütz ulcer is a non-sexually transmitted rare and, probably, underdiagnosed condition, characterized by the sudden onset of vulvar edema along with painful necrotic ulcerations. Despite its unknown incidence, this seems to be an uncommon entity, with sparse cases reported in the literature. We report the case of an 11-year-old girl who presented at the emergency department with vulvar ulcers. She denied any sexual intercourse. The investigation excluded sexually transmitted infections, so, knowledge of different etiologies of non-venereal ulcers became essential. The differential diagnoses are extensive and include inflammatory processes, drug reactions, trauma, and malignant tumors. Lipschütz ulcer is a diagnosis of exclusion. With the presentation of this case report, the authors aim to describe the etiology, clinical course, and outcomes of this rare disease, to allow differential diagnosis of genital ulceration.
Immunological Characteristics between αβ TDC and γδ TDC Cells in the Spleen of Breast Cancer-Induced Mice
Authors: Silva Polyana Barbosa , Michelin Márcia Antoniazi , Jammal Millena Prata , Murta Eddie Fernando Cândido
Published: June 2021

Objective To evaluate the antitumoral role of γδ TDC cells and αβ TDC cells in an experimental model of breast cancer.

Methods Thirty female Balb/c mice were divided into 2 groups: control group (n = 15) and induced-4T1 group (n = 15), in which the mice received 2 × 105 4T1 mammary tumor cell line. Following the 28-day experimental period, immune cells were collected from the spleen and analyzed by flow cytometry for comparison of αβ TDC (TCRαβ+ CD11c+MHCII+) and γδ TDC (TCRγδ+CD11c+MHCII+) cells regarding surface markers (CD4+ and C8+) and cytokines (IFN-γ, TNF-α, IL-12 and IL-17).

Results A total of 26.53% of γδ TDC - control group (p < 0.0001) - the proportion of αβ TDC was lower in splenic cells than γδ TDC; however, these 2 cell types were reduced in tumor conditions (p < 0.0001), and the proportion of IFN-γ, TNF-α, IL-12 and IL-17 cytokines produced by γδ TDC was higher than those produced by αβ TDC, but it decreased under conditions of tumor-related immune system response (p < 0.0001).

Conclusion Healthy mice engrafted with malignant cells 4T1 breast tumor presented TDC with γδ TCR repertoire. These cells express cytotoxic molecules of lymphocytes T, producing anti-tumor proinflammatory cytokines.
Recurrent Primary Sclerosing Cholangitis: Current Understanding, Management, and Future Directions
Authors: Leung Kristel K. , Deeb Maya , Fischer Sandra E. , Gulamhusein Aliya
Published: June 2021

Patients with primary sclerosing cholangitis (PSC) constitute 5 to 15% of patients listed for liver transplantation worldwide. Although post-transplant outcomes are favorable, recurrent PSC (rPSC) occurs in an important subset of patients, with higher prevalence rates reported with increasing time from transplant. Given its association with poor graft outcomes and risk of retransplant, effort has been made to understand rPSC, its pathophysiology, and risk factors. This review covers these facets of rPSC and focuses on implicated risk factors including pretransplant recipient characteristics, inflammatory bowel-disease-related factors, and donor-specific and transplant-specific factors. Confirming a diagnosis of rPSC requires thoughtful consideration of alternative etiologies so as to ensure confidence in diagnosis, management, subsequent risk assessment, and counseling for patients. Unfortunately, no cure exists for rPSC; however, future large-scale efforts are underway to better characterize the natural history of rPSC and its associated risk factors with hopes of identifying potential key targets for novel therapies.
Breast Milk and Breastfeeding of Infants Born to SARS-CoV-2 Positive Mothers: A Prospective Observational Cohort Study
Authors: Kunjumon Bgee , Wachtel Elena V. , Lumba Rishi , Quan Michelle , Remon Juan , Louie Moi , Verma Sourabh , Moffat Michael A. , Kouba Insaf , Bennett Terri-Ann , Mejia Claudia Manzano De , Mally Pradeep V. , Lin Xinhua , Hanna Nazeeh
Published: June 2021

Objective There are limited published data on the transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus from mothers to newborns through breastfeeding or from breast milk. The World Health Organization released guidelines encouraging mothers with suspected or confirmed COVID-19 to breastfeed as the benefits of breastfeeding outweighs the possible risk of transmission. The objective of this study was to determine if SARS-CoV-2 was present in the breast milk of lactating mothers who had a positive SARS-CoV-2 nasopharyngeal swab test prior to delivery, and the clinical outcomes for their newborns.

Study Design This was a single-center, observational, prospective cohort study. Maternal–newborn dyads that delivered at New York University Langone Hospital Brooklyn with confirmed maternal SARS-CoV-2 positive screen test at the time of admission were recruited for the study. Breast milk samples were collected during postpartum hospitalization and tested for the presence of SARS-CoV-2 genes N1 and N2 by two-step reverse transcription polymerase chain reaction. Additionally, the clinical characteristics of the maternal newborn dyad, results of nasopharyngeal SARS-CoV-2 testing, and neonatal follow-up data were collected.

Results A total of 19 mothers were included in the study and their infants who were all fed breast milk. Breast milk samples from 18 mothers tested negative for SARS-CoV-2, and 1 was positive for SARS-CoV-2 RNA. The infant who ingested the breast milk that tested positive had a negative nasopharyngeal test for SARS-CoV-2, and had a benign clinical course. There was no evidence of significant clinical infection during the hospital stay or from outpatient neonatal follow-up data for all the infants included in this study.

Conclusion In a small cohort of SARS-CoV-2 positive lactating mothers giving birth at our institution, most of their breast milk samples (95%) contained no detectable virus, and there was no evidence of COVID-19 infection in their breast milk-fed neonates.

Key Points
New Greek migrant (dis)identifications in social media: Evidence from a discourse-centred online ethnographic study
Authors: Georgalou Mariza
Published: June 2021

Since the eruption of the Greek crisis in 2010, thousands of highly educated and skilled Greeks have chosen or have been forced to migrate abroad in pursuit of better career prospects and living standards. This recent migratory wave has been termed ‘new’ Greek migration (Panagiotopoulou et al., 2019). Considering the transformative impact of social media on the lives and experiences of migrants as well as the pivotal role of social media in (dis)identification and identity construction processes, this paper aims at exploring the ways in which new Greek migrants construct their identities in their social media discourse. Based on a synergy between the constructionist approach to identity, discourse studies, and online ethnography, the paper presents and discusses empirical data (social media content and interviews) from five selected new Greek migrants settled in the UK and Germany, who write about and capture their migration experiences on their blogs, Facebook, Twitter, and Instagram accounts. As shown in the analysis, new Greek migrant identities are hybrid and multifaceted, constructed and negotiated through a gamut of discursive means, including stance-taking, intertextuality, entextualization, and coupling. Having the migrants’ own voice and perspective at the heart of the analysis brings to the forefront significant socio-cultural dimensions of new Greek migration, often downplayed in economic and political analyses of the phenomenon. In this fashion, the potential of social media to heighten awareness of new Greek migrants’ (dis)identification processes is verified.
Absolute laser energy absorption measurement of relativistic 0.7 ps laser pulses in nanowire arrays
Authors: Park J. , Tommasini R. , Shepherd R. , London R. A. , Bargsten C. , Hollinger R. , Capeluto M. G. , Shlyaptsev V. N. , Hill M. P. , Kaymak V. , Baumann C. , Pukhov A. , Cloyne D. , Costa R. , Hunter J. , Maricle S. , Moody J. , Rocca J. J.
Published: June 2021

Laser absorption is one of the most important parameters governing laser–matter interactions. The laser energy absorption on nanowire array targets is measured for the first time in the relativistic regime at intensities of 1019 W/cm2 and compared to foil targets. The results show that the laser energy absorption of 0.7 ps frequency doubled (527 nm) pulses on Au nanowire targets varies widely with nanowire parameters, reaching laser energy absorption values up to ∼71% of the incident energy, significantly exceeding those of solid flat targets obtained in similar irradiation conditions. The analysis shows that the increase in absorption strongly correlates with larger effective target surface area over a broad range of nanowire parameters explored. These direct absorption measurements provide valuable data to benchmark simulations of the relativistic laser pulse interactions with nanostructures.
A new tri-particle backlighter for high-energy-density plasmas (invited)
Authors: Sutcliffe Graeme , Adrian Patrick , Pearcy Jacob , Johnson Timothy , Kabadi Neel , Haque Shaherul , Parker Cody , Lahmann Brandon , Frenje Johan , Gatu-Johnson Maria , Sio Hong , Séguin Fredrick , Pollock Brad , Moody John , Glebov Vladmir , Janezic Roger , Koch Michael , Petrasso Richard , Li Chikang
Published: June 2021

A new tri-particle mono-energetic backlighter based on laser-driven implosions of DT3He gas-filled capsules has been implemented at the OMEGA laser. This platform, an extension of the original D3He backlighter platform, generates 9.5 MeV deuterons from the T3He reaction in addition to 14.7 and 3.0 MeV protons from the deuterium and helium-3 reactants. The monoenergetic 14.7 and 3.0 MeV protons have been used with success at OMEGA and the NIF for both radiography and stopping-power studies. There are several advantages of having a third particle to diagnose plasma conditions: an extra time-of-flight-separated radiograph and an improved ability to discern between electric and magnetic fields. In cases where the 3.0 MeV protons cannot penetrate an experiment, the benefit of the additional 9.5 MeV deuterons is magnified. This capability is well-suited for NIF experiments, where large fields and plasma densities often preclude useful 3.0 MeV proton data. The advantages are demonstrated with radiographs of OMEGA plasmas with magnetic and electric fields. Tests using backlighter-scale 420 μm diameter thin glass capsules validate the platform’s extended backlighting capability. The performance characteristics of this backlighter, such as source size and timing, are discussed.
Thermal effect inside bubbles for weakly nonlinear pressure waves in bubbly liquids: Theory on short waves
Authors: Kanagawa Tetsuya , Kamei Takafumi
Published: June 2021

In this study, weakly nonlinear pressure waves in quiescent compressible liquids comprising several uniformly-distributed spherical microbubbles, at moderately high-frequency and short-wavelength, are theoretically investigated. The energy equation at the bubble–liquid interface and the effective polytropic exponent are utilized to clarify thermal effects inside bubbles on wave dissipation. In addition, thermal conduction is investigated in detail using four temperature-gradient models. The following results are drawn: (i) Nonlinear Schrödinger equation is derived as an effective equation, wherein three types of dissipation factors, i.e., liquid viscosity, liquid compressibility, and thermal conduction, are unified into a linear combination as the dissipation coefficient. This is different from our previous result treating the low-frequency and long-wavelength case [Kamei et al., Phys. Fluids 33, 053302 (2021)], i.e., two types of dissipation terms appeared and did not unify into a linear combination. (ii) Dissipation due to thermal conduction is more than four times larger than that due to other dissipation factors. (iii) Dissipation due to thermal conduction at the bubble–liquid interface is considerably larger than that due to thermal conduction through the bubbly liquid. (iv) It is found that the dissipation effect in the short-wave case is smaller than that in the long-wave case.
An Au2S network model for exploring the structural origin, evolution, and two-electron (2e−) reduction growth mechanism of Aun(SR)m clusters
Authors: Wang Pu , Peng Jiao , Pei Yong
Published: June 2021

An Au2S network model was proposed to study the structural origin, evolution, and formation mechanism of the Aun(SR)m clusters containing quasi-face-centered-cubic (fcc) cores. The Au–S framework structures of 20 quasi-fcc gold clusters had been determined from the Au2S network. Based on the Au2S network, some new quasi-fcc clusters, such as 8e− clusters Au24(SR)16, Au26(SR)18, Au26(SR)19−, Au29(SR)21, Au30(SR)22, and Au32(SR)24, and a class of Au24+8n(SR)20+4n (n = 1, 2, 3, …) clusters were predicted. Furthermore, by studying the evolution of Au–S frameworks, it was possible to construct molecular-like reaction equations to account for the formation mechanism of quasi-fcc gold clusters, which indicated that the formation of quasi-fcc gold clusters can be understood from the stepwise 2e−-reduction cluster growth pathways. The present studies showed that the Au2S network model provided a “parental” Au–S network for exploring the structural evolution of the quasi-fcc Aun(SR)m clusters. Moreover, it was possible to study the formation pathways of the Aun(SR)m clusters by studying the evolution of their Au–S frameworks.
Comparison of the dielectric and magnetocaloric properties of bulk and film of GdFe0.5Cr0.5O3
Authors: Shi Jianhang , Seehra Mohindar S. , Dang Yanliu , Suib Steven L. , Jain Menka
Published: June 2021

Reported here is a comparison of the magnetic, magnetocaloric, and dielectric properties of 50% iron substituted GdCrO3 (GdFe0.5Cr0.5O3) bulk pellet and 960 nm thick film of GdFe0.5Cr0.5O3 (GFCO). The 960 nm film was synthesized on a platinized-silicon substrate by chemical solution deposition and spin-coating methods. The X-ray diffraction scans of the bulk sample and the film as well as the morphology of the film as examined by the field-emission scanning electron microscope indicate phase-pure and polycrystalline nature of these samples. X-ray photoelectron spectroscopy was used to determine the valence states of Gd, Fe, and Cr. The temperature dependence of the dielectric constant from 225 to 700 K shows peaks at TC = 525 K for the bulk and ∼450 K for the film due to ferroelectric to paraelectric transitions, since electric polarization vs electric field hysteresis loops are observed at room temperature. The dielectric studies in the bulk GFCO for T > TC indicate a relaxor-like behavior. The measurements of the magnetization (M) of the samples as a function of temperature (5–350 K) and magnetic field (H) up to 7 T (=70 kOe) depict hysteresis behavior at low temperatures due to the canted antiferromagnetic order of Fe3+/Cr3+ below the Néel temperature of ∼275 K. The M vs H isotherms at various temperatures are used to determine and compare the magnetic entropy change (−ΔS) and relative cooling power (RCP) of the two samples, yielding (−ΔS) = 30.7 J/kg K (18.8 J/kg K) and RCP = 566.5 J/kg (375 J/kg) for the bulk (960 nm film) samples of GFCO at 7 K and 7 T, respectively. The plot of RCP vs T shows that magnetic cooling for this system is most effective for T < 30 K. Comparatively smaller magnitudes of (−ΔS) and RCP for the film vis-à-vis the bulk sample of GFCO scale with its reduced magnetization. This suggests that further improvements in the quality of the films are needed to improve their magnetization and hence their magnetocaloric properties, possibly making them useful for on-chip cooling in miniaturized devices.
First principles reactive simulation for equation of state prediction
Authors: Jadrich Ryan B. , Ticknor Christopher , Leiding Jeffery A.
Published: June 2021

The high cost of density functional theory (DFT) has hitherto limited the ab initio prediction of the equation of state (EOS). In this article, we employ a combination of large scale computing, advanced simulation techniques, and smart data science strategies to provide an unprecedented ab initio performance analysis of the high explosive pentaerythritol tetranitrate (PETN). Comparison to both experiment and thermochemical predictions reveals important quantitative limitations of DFT for EOS prediction and thus the assessment of high explosives. In particular, we find that DFT predicts the energy of PETN detonation products to be systematically too high relative to the unreacted neat crystalline material, resulting in an underprediction of the detonation velocity, pressure, and temperature at the Chapman–Jouguet state. The energetic bias can be partially accounted for by high-level electronic structure calculations of the product molecules. We also demonstrate a modeling strategy for mapping chemical composition across a wide parameter space with limited numerical data, the results of which suggest additional molecular species to consider in thermochemical modeling.
Theory of two-dimensional spectroscopy with intense laser fields
Authors: Bressan Giovanni , van Thor Jasper J.
Published: June 2021

Two-dimensional vibrational and electronic spectroscopic observables of isotropically oriented molecular samples in solution are sensitive to laser field intensities and polarization. The third-order response function formalism predicts a signal that grows linearly with the field strength of each laser pulse, thus lacking a way of accounting for non-trivial intensity-dependent effects, such as saturation and finite bleaching. An analytical expression to describe the orientational part of the molecular response, which, in the weak-field limit, becomes equivalent to a four-point correlation function, is presented. Such an expression is evaluated for Liouville-space pathways accounting for diagonal and cross peaks for all-parallel and cross-polarized pulse sequences, in both the weak- and strong-field conditions, via truncation of a Taylor series expansion at different orders. The results obtained in the strong-field conditions suggest how a careful analysis of two-dimensional spectroscopic experimental data should include laser pulse intensity considerations when determining molecular internal coordinates.
Adsorption of gas molecules on Co-doped SnO2 (110): First-principles investigation
Authors: Lin Long , Chen Ruixin , Huang Jingtao , Zhu Linghao , Wang Pengtao , Yan Longbin , Lou Mengsi , Chen Yujin , Tao Hualong , Zhang Zhanying
Published: June 2021

First-principles calculations based on density functional theory were employed to study the adsorption of gas molecules (CH4, CO, H2O) on various SnO2 (110) surfaces. We found that CO and CH4 molecules are weakly adsorbed on intrinsic SnO2 (110) surfaces, and intrinsic SnO2 is sensitive only to the H2O molecule. Compared with the gas molecules adsorbed on the intrinsic SnO2 surfaces, the significantly increased adsorption energy indicates that there is an improvement in the gas sensitivity properties of Co-doped SnO2 (Co/SnO2) and oxygen vacancy modified Co-doped SnO2 (Co/VO/SnO2) to CO, CH4, and H2O gas. The CO adsorbed on the Co/VO/SnO2 surface has the strongest adsorption energy (−1.402 eV). We also studied the optical properties of the Co/SnO2 and Co/VO/SnO2 surfaces influenced by the three gas molecules. We found that the three gas molecules cause an enhancement of the adsorption peaks of Co/SnO2 configuration in the visible light range. Our study benefits research on the potential application of SnO2 sensor materials.
Synergism of dynamics of tetrahedral hydrogen bonds of liquid water
Authors: Kholmanskiy Alexander
Published: June 2021

We used modified Arrhenius approximations to analyze known temperature dependences (TDs) of water microstructure parameters and its dielectric and dynamic characteristics. Analysis of activation energies showed a significant difference in the molecular dynamics of water in ranges 273–298 and 300–373 K. Features of TDs in the first range were associated with the dynamics of a metastable ice-like phase of water, in which hexagonal clusters with tetrahedral hydrogen bonds (HBs) predominate. Based on ratios of signs and values of activation energies of HBs' fluctuations and parameters of a microstructure, it was assumed that fluctuations of HBs' dipoles play a key role in the mechanism of resonant activation by a thermal energy of concertedly reactions of deformation, rupture, and formation of tetrahedral HBs in water clusters. Synergism of these reactions and interaction of charges of the vacant acceptor and donor tetrahedral orbitals of an oxygen atom trigger at 298 K an explosive transition of a metastable ice-like phase of water into an argon-like phase. Synergy of water dynamics above 298 K is adequately characterized by the product Dη, from which TDs follow the activation energies of reactions that determine the form of Stokes–Einstein relation in temperature ranges below and above 298 K point.
On the self-similarity of diffracting gaseous detonations and the critical channel width problem
Authors: Radulescu M. I. , Mével R. , Xiao Q. , Gallier S.
Published: June 2021

One strategy for arresting propagating detonation waves in pipes is by imposing a sudden area enlargement, which provides a rapid lateral divergence of the gases in the reaction zone and attenuates the leading shock. For sufficiently small tube diameter, the detonation decays to a deflagration and the shock decays to negligible strengths. This is known as the critical tube diameter problem. In the present study, we provide a closed form model to predict the detonation quenching for 2D channels. Whitham's geometric shock dynamics, coupled with a shock evolution law based on shocks sustained by a constant source obtained by the shock change equations of Radulescu, is shown to capture the lateral shock dynamics response to the failure wave originating at the expansion corner. A criterion for successful detonation transmission to open space is that the lateral strain rate provided by the failure wave does not exceed the critical strain rate of steady curved detonations. Using the critical lateral strain rate obtained by He and Clavin, a closed form solution is obtained for the critical channel opening permitting detonation transmission. The predicted critical channel width is found in very good agreement with our recent experiments and simulations of diffracting H2/O2/Ar detonations.
Impact of conductivity type change in InAs/GaSb superlattice on low frequency noise of photoconductive long-wavelength infrared detectors
Authors: Ciura Łukasz , Jasik Agata , Czuba Krzysztof
Published: June 2021

This Letter focuses on the 1/f noise properties of InAs/GaSb superlattice (SL), which is a promising material for infrared radiation detection and represents one of the alternatives to well-established bulk HgCdTe material. The InAs/GaSb SL material changes the conductivity type at temperature T ≈ 190 K, which has been correlated with measured 1/f noise. It was shown that 1/f noise comes from resistance fluctuations of linear noise sources. According to the electronic transport and 1/f noise models, the observed 1/f noise is connected with the hole conductivity component rather than the electron conductivity component, which is absent or at least immeasurable, even though electron conductivity governs the total conductivity of the InAs/GaSb SL. In the high-temperature region, the 1/f noise of InAs/GaSb SL is significantly smaller than that of InAs/InAsSb SL. The results favor InAs/GaSb SL material over InAs/InAsSb SL for photoconductive infrared detectors operating at room temperature.
Scaling of global properties of fluctuating and mean streamwise velocities in pipe flow: Characterization of a high Reynolds number transition region
Authors: Basse Nils T.
Published: June 2021

We study the global, i.e., radially averaged, high Reynolds number (asymptotic) scaling of streamwise turbulence intensity squared defined as I2=u2¯/U2, where u and U are the fluctuating and mean velocities, respectively (overbar is time averaging). The investigation is based on the mathematical abstraction that the logarithmic region in wall turbulence extends across the entire inner and outer layers. Results are matched to spatially integrated Princeton Superpipe measurements [Hultmark et al., “Logarithmic scaling of turbulence in smooth- and rough-wall pipe flow,” J. Fluid Mech. 728, 376–395 (2013)]. Scaling expressions are derived both for log- and power-law functions of radius. A transition to asymptotic scaling is found at a friction Reynolds number Reτ∼11 000.
Numerical simulation of non-isothermal drainage flow of a viscous gas from a narrow channel
Authors: Huang Wei , Chen Kang Ping
Published: June 2021

Drainage of a compressed viscous gas from a semi-sealed narrow conduit to a large container is a model problem of fundamental interest to fluid production from subsurface porous rocks. The low Mach number drainage flow exhibits behaviors contrary to predictions from conventional incompressible flow approximations. This work employs direct numerical simulation to study non-isothermal drainage flow from a semi-sealed narrow channel to a laterally bounded large container. The Navier–Stokes characteristic boundary conditions are implemented at the open boundary downstream in the computational domain to avoid spurious wave reflection. For a laterally bounded container, wave transport dominates the drainage process. It is shown that in the absence of an imposed temperature drop, thermal effect slows down the drainage process with adiabatic walls. With large enough temperature drop, thermal effect speeds up the drainage, and it also produces excess mass beyond that of the isothermal model. These thermal effects are consistent with the previous results for a laterally unbounded container in a linear theory.
The role of the envelope protein in the stability of a coronavirus model membrane against an ethanolic disinfectant
Authors: Das Shubhadip , Meinel Melissa K. , Wu Zhenghao , Müller-Plathe Florian
Published: June 2021

Ethanol is highly effective against various enveloped viruses and can disable the virus by disintegrating the protective envelope surrounding it. The interactions between the coronavirus envelope (E) protein and its membrane environment play key roles in the stability and function of the viral envelope. By using molecular dynamics simulation, we explore the underlying mechanism of ethanol-induced disruption of a model coronavirus membrane and, in detail, interactions of the E-protein and lipids. We model the membrane bilayer as N-palmitoyl-sphingomyelin and 1-palmitoyl-2-oleoylphosphatidylcholine lipids and the coronavirus E-protein. The study reveals that ethanol causes an increase in the lateral area of the bilayer along with thinning of the bilayer membrane and orientational disordering of lipid tails. Ethanol resides at the head–tail region of the membrane and enhances bilayer permeability. We found an envelope-protein-mediated increase in the ordering of lipid tails. Our simulations also provide important insights into the orientation of the envelope protein in a model membrane environment. At ∼25 mol. % of ethanol in the surrounding ethanol–water phase, we observe disintegration of the lipid bilayer and dislocation of the E-protein from the membrane environment.
Counterflow slip in a two-fluid whirlpool
Authors: Naumov Igor V. , Skripkin Sergey G. , Shtern Vladimir N.
Published: June 2021

This experimental study reveals a counterflow slip at the interface of two immiscible fluids filling a sealed vertical cylindrical container whose bottom disk rotates while other walls are stationary. An advanced particle image velocimetry helps us analyze and quantify streamline patterns and velocity profiles of the steady axisymmetric flows of both fluids. As the angular velocity of a disk increases, starting from zero, three changes occur in topology of the upper-fluid flow while topology of the lower-fluid flow remains invariant. These changes result in the counterflow slip at the entire interface, whose nature is speculatively discussed and requires further research.
Electrical transport modulation of VO2/Si(111) heterojunction by engineering interfacial barrier height
Authors: Roul Basanta , Singh Deependra Kumar , Pant Rohit , Chowdhury Arun Malla , Nanda K. K. , Krupanidhi S. B.
Published: June 2021

Smart multifunctional materials such as vanadium dioxide (VO2), which exhibit a reversible semiconductor-to-metal transition (SMT), provide a new route toward engineering high speed switchable devices. Here, we present a detailed report on the modulation in the electrical properties of VO2/Si heterostructures by application of an external electrical field across VO2 thin films. Single-phase VO2 thin films have been deposited on an Si(111) substrate using the pulsed laser deposition technique. The electrical transport behavior across the VO2/Si heterostructure has been studied in the temperature range of 35–105 °C, and a reversible SMT can be seen at 68 and 63 °C for heating and cooling cycles, respectively. The temperature-dependent resistance of the device shows a hysteresis loop around the transition temperature of the VO2 thin film. In addition, the device shows a significant change in junction current when an external bias is applied on the VO2 thin film, and this phenomenon has been utilized to study the switching behavior of the device. Such behavior is due to the change in interfacial barrier height because of the bias dependent tilting of electronic energy bands of the VO2 thin film. Our results offer novel opportunities to externally control the electrical transport of vertical heterostructures and can be beneficial for extending the notion of electrical field modulation in electrical switches and sensors.
Quantum Hall effect of the topological insulator state of cadmium arsenide in Corbino geometry
Authors: Galletti Luca , Rashidi Arman , Kealhofer David A. , Goyal Manik , Guo Binghao , Li Yuntian , Shang Chen , Bowers John E. , Stemmer Susanne
Published: June 2021

The surfaces of a three-dimensional topological insulator each host a single Dirac fermion, which, in a strong magnetic field, contribute to the transverse conductance in integer-and-a-half multiples of the conductance quantum. The direct observation of this extra half integer, the hallmark of the two-dimensional Dirac state, is usually thwarted by the fermion doubling theorem—top and bottom surfaces are not measured independently. Here, we employ a Corbino measurement geometry in which a current, induced by an ac magnetic field, is driven around the ring, as a complementary measurement to the conventional Hall bar geometry. As the device enters the quantum Hall regime, the transverse voltage reaches a series of plateaus when the current is carried by the incompressible bulk states. We compare the results with the corresponding Hall bar measurements.
Nonvolatile switching of magnetostrictive nanodot from single-domain to vortex states by voltage at room temperature
Authors: Liu J. H. , Yang X. K. , Cui H. Q. , Hong D. H. , Li C. , Chen Y. B. , Xu N. , Yang B. B. , Qiu S. , Zhu J. W. , Fang L.
Published: June 2021

We report the voltage regulation of electrodeposited elliptical magnetostrictive Ni nanodot arrays from single-domain to nonvolatile vortex state at room temperature. On the piezoelectric substrate, isolated elliptical Ni nanodots are fabricated between a pair of square electrodes, with the long axis parallel to the joint line of the electrodes. By applying a voltage to the surface electrodes pair, local stress is generated to induce the magnetization of the nanodots from single-domain to vortex state. The magnetization state of the nanodots is characterized by a magnetic force microscope. Even after the voltage is removed or applying another voltage, the nanodots maintain a stable vortex magnetization state, which shows that the vortex state after regulation is nonvolatile. These results are of great significance for the study of the low-energy-consumption regulation of the nano-dimensional magnetic material and vortex state-based nonvolatile memory.
An evaluation of automated dispensing cabinets and inventory robots for centralised distribution of medication in an Australian hospital
Authors: Fox Emma , Misko Jeanie , Cheaib Angela , Caird Paula , Tam Kenneth , Rawlins Matthew , Jenkins Barry
Published: June 2021

Objective In Australian hospitals, a central distribution system is often utilised to supply medication to clinical areas. This study investigated the impact of automated dispensing cabinets (ADCs) and inventory robots in medication distribution within an Australian hospital. Methods A prospective observational study of pharmacy technician medication supply to clinical areas was conducted over a 2-week period pre- and post-implementation of ADCs and inventory robots. Information was collected on the time taken to perform all tasks required to provide a weekly medication supply service for medication other than drugs of addiction. Results There was no significant reduction of total duration for medication supply, pre-implementation mean 73.08 min versus post-implementation 68.59 min (P = 0.567). An instance of automation downtime occurred during the post-implementation period for which manual downtime procedures were implemented. Without downtime, a significant reduction in overall time taken was observed, 74.25 min versus 63.18 min (P = 0.019). Pre-restocking medication selection errors were reduced non-significantly after implementation of inventory robots, 11 (0.43%) versus 4 (0.21%) errors (P = 0.090). Conclusions Implementation of ADCs and robots did not significantly reduce the total time to provide a weekly medication supply service when downtime occurred, although a significant reduction was observed when downtime did not occur. Pharmacy medication selection errors were non-significantly lower. What is known about the topic? Australian hospitals are increasingly implementing automated technology such as ADCs and inventory robotics in an attempt to improve efficiency and accuracy of medication supply; however, limited literature is available in an Australian setting. What does this paper add? This paper describes the impact of implementing ADCs in clinical areas (e.g. inpatient wards) and inventory robots in a main store pharmacy on the medication supply process. This paper highlights the benefit of improved efficiency and accuracy in selecting medication in pharmacy for distribution and identifies time to restock the ADCs is significantly increased. What are the implications for practitioners? Implementing ADCs and inventory robotics in Australian hospitals can provide benefits in efficiency and accuracy; however, robust downtime procedures are essential.