bluuebunny/crossref_metadata_2025 huggingface dataset:
Closure of the Proterozoic Mozambique Ocean was instigated by a late Tonian plate reorganization event
Authors: Collins Alan S. , Blades Morgan L. , Merdith Andrew S. , Foden John D.
Published: April 2021

Plate reorganization events involve fundamental changes in lithospheric plate-motions and can influence the lithosphere-mantle system as well as both ocean and atmospheric circulation through bathymetric and topographic changes. Here, we compile published data to interpret the geological record of the Neoproterozoic Arabian-Nubian Shield and integrate this with a full-plate tectonic reconstruction. Our model reveals a plate reorganization event in the late Tonian period about 720 million years ago that changed plate-movement directions in the Mozambique Ocean. After the reorganization, Neoproterozoic India moved towards both the African cratons and Australia-Mawson and instigated the future amalgamation of central Gondwana about 200 million years later. This plate kinematic change is coeval with the breakup of the core of Rodinia between Australia-Mawson and Laurentia and Kalahari and Congo. We suggest the plate reorganization event caused the long-term shift of continents to the southern hemisphere and created a pan-northern hemisphere ocean in the Ediacaran.
Direct translocation of a negatively charged nanoparticle across a negatively charged model cell membrane
Authors: Ikeda Yoko , Nakamura Hideya , Ohsaki Shuji , Watano Satoru
Published: April 2021

Negatively charged nanoparticle can directly translocate across negatively charge cell membrane via a non-disruptive pathway under a weak external electric field with an ionic charge imbalance.
Effects of Pediococcus pentosaceus LI05 on immunity and metabolism in germ-free rats
Authors: Jiang Shiman , Xia Jiafeng , Lv Longxian , Wang Qiangqiang , Li Yating , Xu Qiaomai , Bian Xiaoyuan , Ye Jianzhong , Yang Liya , Jiang Huiyong , Yan Ren , Wang Kaicen , Fang Daiqiong , Li Lanjuan
Published: April 2021

Many Pediococcus spp. have health-promoting benefits, and Pediococcus pentosaceus LI05 is one such species that was proved to be beneficial in previous studies.
Fragmentation, catenation, and direct functionalisation of white phosphorus by a uranium(iv)–silyl–phosphino–carbene complex
Authors: Boronski Josef T. , Seed John A. , Wooles Ashley J. , Liddle Stephen T.
Published: April 2021

Unprecedented insertion of P4 into a MC double bond is reported, revealing overall catenation via P4-fragmentation into R2CP2 units.
An innovative GC-MS, NMR and ESR combined, gas-phase investigation during chemical vapor deposition of silicon oxynitrides films from tris(dimethylsilyl)amine
Authors: Decosterd Laura , Topka Konstantina Christina , Diallo Babacar , Samelor Diane , Vergnes Hugues , Senocq François , Caussat Brigitte , Vahlas Constantin , Menu Marie-Joëlle
Published: April 2021

Coupled analysis by GC-MS, ESR, NMR during CVD of SiOxNy implemented for the first time, highlighting reaction pathways. Silanamine precursor serves as dual source of Si and N, producing silylated radicals and at least fifteen gaseous by-products.
An electrically conducting molecular crystal composed of a magnetic iron(iii) complex (S = 1/2) with a large aromatic ligand, 1,2-naphthlalocyanine (C4h isomer): towards the development of molecular spintronics
Authors: Yamaguchi Masayuki , Iwamura Sayaka , Mine Kosuke , Murakawa Hiroshi , Hanasaki Noriaki , Matsuda Masaki
Published: April 2021

An electrically conducting molecular crystal, Ph4P[FeIII(1,2-Nc)(CN)2]2 (Ph4P = tetraphenylphosphonium and 1,2-Nc = C4h isomer of 1,2-naphthalocyanine), was fabricated as a new coordination compound with a strong π–d interaction.
Molecular light-upconversion: we have had a problem! When excited state absorption (ESA) overcomes energy transfer upconversion (ETU) in Cr(iii)/Er(iii) complexes
Authors: Golesorkhi Bahman , Taarit Inès , Bolvin Hélène , Nozary Homayoun , Jiménez Juan-Ramón , Besnard Céline , Guénée Laure , Fürstenberg Alexandre , Piguet Claude
Published: April 2021

Near-infrared to visible molecular upconversion exhibits quantum yields which are 2–6 orders of magnitude larger than those modeled with the accepted linear excited state absorption (ESA) or energy transfer (ETU) mechanisms: we have had a problem!
Mitigation of vacancy with ammonium salt-trapped ZIF-8 capsules for stable perovskite solar cells through simultaneous compensation and loss inhibition
Authors: Li Chi , Guo Shanshan , Chen Jingan , Cheng Zhibin , Zhu Mengqi , Zhang Jindan , Xiang Shengchang , Zhang Zhangjing
Published: April 2021

Sustained-release capsules were introduced to simultaneously compensate vacancies and reduce ammonium cation loss in perovskite.
Self-healing functionalization of sulfonated hafnium oxide and copper oxide nanocomposite for effective biocidal control of multidrug-resistant bacteria
Authors: Manoharan Ranjith Kumar , Gangadaran Prakash , Ayyaru Sivasankaran , Ahn Byeong-Cheol , Ahn Young-Ho
Published: April 2021

The combination of copper and sulfonated hafnium oxide nanoparticles could be used as an alternative antimicrobial agent to combat multidrug resistant bacteria and membrane biofouling.
Boosting intermolecular interactions of fused cyclic explosives: the way to thermostable and insensitive energetic materials with high density
Authors: Chen Xiang , Guo Zhaoqi , Zhang Cong , Zhang Jianguo , Ma Haixia
Published: April 2021

Improving the packing efficiency of explosives by strong intermolecular interactions can acquire high density while avoiding the expense of stability.
Photoredox halogenation of quinolones: the dual role of halo-fluorescein dyes
Authors: Ritu  , Kumar Sharvan , Chauhan Parul , Jain Nidhi
Published: April 2021

An unprecedented visible light mediated regioselective C-3 halogenation of quinolones was achieved using halo-fluorescein dyes as a halogen source and air as an oxidant. This reaction has broad substrate scope and gives 3-halo quinolone derivatives.
Spatio-temporally controlled suppression of the coffee-ring phenomenon by cellulose nanofibers
Authors: Koyama Naoto , Hanasaki Itsuo
Published: April 2021

A droplet with a small portion of cellulose nanofibers (CNFs) has low viscosity to be compatible with inkjet discharge, but CNFs form structural order to prevent the coffee-ring phenomenon at the last stage of drying of the sessile droplet.
A self-healing, recyclable, and degradable fire-retardant gelatin-based biogel coating for green buildings
Authors: Zhang Lei , Huang Yubin , Sun Ping , Hai Yun , Jiang Saihua
Published: April 2021

Application of a self-healing, recyclable and fire-retardant gelatin-based biogel coating is a sustainable and eco-friendly method for the fire safety of green buildings.
Drastic changes of the amphipod fauna in northern Germany and the displacement of Gammarus lacustris G.O. Sars, 1864 to relict habitats/status
Authors: Meßner Ulrich , Zettler Michael Lothar
Published: April 2021

The amphipod fauna of Central Europe has changed dramatically over the last century. This change has increased dramatically over the past 30 years. This dynamic is well documented in northeast Germany. This study places it in a landscape-ecological context. An example of a displacement is Gammarus lacustris G.O. Sars, 1864, a circumpolar species with a variety of habitats, but relegated to relic habitats. The species turns out to be a very weak competitor. Already with the immigration of Gammarus roeselii Gervais, 1835 (probably in the 1960s), it became a relic species in northeast Germany. Massive waves of introduction of Pontocaspian species of the genera Dikerogammarus, Pontogammarus and Echinogammarus a few decades later intensified this process for this and other species.
Klebsiella Pneumoniae Liver Abscess Syndrome – A Challenge for
Contrast-Enhanced Ultrasound
Authors: Bielow Tobias , Blank Valentin , Opitz Sabine , Gößmann Holger , Hecker Martin , Seehofer Daniel , Lübbert Christoph , Karlas Thomas
Published: April 2021

Introduction

Invasive liver abscess syndrome (ILAS) is caused by strains of hypervirulent
Klebsiella pneumoniae (hvKp) and has emerged as the leading cause of liver abscesses
in immuno-competent patients (L.K. Siu et al. Lancet Infect Dis 2012; 12:
881–87). ILAS is frequently associated with metastatic spread including the
eyes, lungs, and the central nervous system. The morbidity and mortality of affected
patients are increased compared to liver abscesses of other origin, especially in
cases with concomitant diabetes mellitus (J. E. Choby et al. J Intern Med 2020;
287(3): 283–300). Immediate diagnosis and early intervention are essential
for an optimal outcome. Therefore, ultrasound plays a crucial role if hvKp is
suspected. However, experience with the characteristics of such abscesses on
contrast-enhanced ultrasound (CEUS) is very limited.
Effects of Different Onset Times of Early Caffeine Treatment on Mesenteric Tissue Oxygenation and Necrotizing Enterocolitis: A Prospective, Randomized Study
Authors: Ozkan Hilal , Cetinkaya Merih , Cakir Salih C. , Saglam Ozge , Koksal Nilgun
Published: April 2021

Objective Caffeine treatment is routinely used in premature infants to prevent development of apnea and bronchopulmonary dysplasia. Although a limited number of studies have reported that early caffeine treatment may cause development of necrotizing enterocolitis (NEC) by reducing mesenteric blood flow, this issue is still under discussion. The aim of this study is to investigate the possible effect of different onset times of early caffeine treatment on mesenteric tissue oxygen saturation and NEC development in premature infants.

Study Design A total of 87 preterm infants with ≤1,250-g birth weight (BW) was included in this prospective study. The cases were randomized as group 1 (first 24 hours) and group 2 (72nd hour) caffeine treatment groups and monitored by near-infrared spectroscopy (NIRS) for 72 hours from the time of admission until cerebral, renal, and mesenteric tissue oxygen saturations (rSO2) were recorded. The cases were followed-up to the 40th week in terms of NEC and other neonatal morbidities.

Results A total of 87 infants were included in the study, including 45 in group 1 and 42 in group 2. The groups were similar in terms of demographic characteristics. The incidence of NEC in group 1 (20%) was higher in comparison to group 2 (9%). The mesenteric rSO2 values in the first 72 hours of group 1 were lower than those of group 2. Low gestational week, BW, and late onset of enteral feeding were found to be other significant risk factors for NEC.

Conclusion In this study, mesenteric tissue oxygenation was lower, and NEC was higher in group 1. Mesenteric rSO2 measurements may be useful in predicting the development of NEC in patients receiving early caffeine therapy.

Key Points
Clinical and Demographic Risk Factors for COVID-19 during Delivery Hospitalizations in New York City
Authors: Sutton Desmond , Wen Timothy , Staniczenko Anna P. , Huang Yongmei , Andrikopoulou Maria , D'Alton Mary , Feinberg Bruce B. , Fuchs Karin , Goffman Dena , Gyamfi-Bannerman Cynthia , Kahe Ka , Landau Ruth , Lasky James A. , Miller Russell , Ntoso Amma D. , Panzer Alexis , Sheen Jean-Ju , Simpson Lynn L. , Friedman Alexander M.
Published: April 2021

Objective This study was aimed to review 4 weeks of universal novel coronavirus disease 2019 (COVID-19) screening among delivery hospitalizations, at two hospitals in March and April 2020 in New York City, to compare outcomes between patients based on COVID-19 status and to determine whether demographic risk factors and symptoms predicted screening positive for COVID-19.

Study Design This retrospective cohort study evaluated all patients admitted for delivery from March 22 to April 18, 2020, at two New York City hospitals. Obstetrical and neonatal outcomes were collected. The relationship between COVID-19 and demographic, clinical, and maternal and neonatal outcome data was evaluated. Demographic data included the number of COVID-19 cases ascertained by ZIP code of residence. Adjusted logistic regression models were performed to determine predictability of demographic risk factors for COVID-19.

Results Of 454 women delivered, 79 (17%) had COVID-19. Of those, 27.9% (n = 22) had symptoms such as cough (13.9%), fever (10.1%), chest pain (5.1%), and myalgia (5.1%). While women with COVID-19 were more likely to live in the ZIP codes quartile with the most cases (47 vs. 41%) and less likely to live in the ZIP code quartile with the fewest cases (6 vs. 14%), these comparisons were not statistically significant (p = 0.18). Women with COVID-19 were less likely to have a vaginal delivery (55.2 vs. 51.9%, p = 0.04) and had a significantly longer postpartum length of stay with cesarean (2.00 vs. 2.67days, p < 0.01). COVID-19 was associated with higher risk for diagnoses of chorioamnionitis and pneumonia and fevers without a focal diagnosis. In adjusted analyses, including demographic factors, logistic regression demonstrated a c-statistic of 0.71 (95% confidence interval [CI]: 0.69, 0.80).

Conclusion COVID-19 symptoms were present in a minority of COVID-19-positive women admitted for delivery. Significant differences in obstetrical outcomes were found. While demographic risk factors demonstrated acceptable discrimination, risk prediction does not capture a significant portion of COVID-19-positive patients.

Key Points
Neonatal Outcomes after Uterus Transplantation: Dallas Uterus Transplant Study
Authors: York Jackie R. , Testa Giuliano , Gunby Robert T. , Putman J. Michael , McKenna Gregory J. , Koon Eric C. , Bayer Johanna , Zhang Lilly , Gregg Anthony R. , Johannesson Liza
Published: April 2021

Objective Limited data are available on the outcome of infants born after uterus transplantation. Our aim was to describe the hospital course and laboratory findings in the first 2 months of life of the 12 infants born in the Dallas UtErus Transplant Study (DUETS).

Study Design Based on the trial protocol, information about infants was collected in a prospective fashion, including infant demographics, hospital course, and laboratory values.

Results Twelve infants were delivered, all by cesarean section, from 11 mothers who had undergone uterus transplantation (one mother had two pregnancies and delivered two babies). All pregnancies were singleton. The mothers received immunosuppressive therapy, and one had a rejection episode that was detected during pregnancy. The rejection episode resolved after steroid treatment. The infants had a median gestational age of 366/7 weeks (range: 306/7–380/7 weeks) and median birth weight of 2,920 g (range: 1,770–3,470 g). The lowest Apgar's score at 5 minutes was 8. All infants were appropriate size for gestational age. Two infants presented with bandemia but negative blood cultures. At 2 months of age, all infants achieved the developmental and behavioral milestones outlined by the American Academy of Pediatrics.

Conclusion The 12 infants born from mothers with uterus transplants had a neonatal course that reflected the gestational age at delivery. No baby was born with an identified malformation or organ dysfunction. Longer follow-up and a larger number of infants are needed to confirm these observations.

Key Points
Comparison of Maternal and Neonatal Subspecialty Care Provision by Hospital
Authors: Clapp Mark A. , Srinivas Sindhu K. , Kozhimannil Katy B. , Grobman William A. , Kaimal Anjali J.
Published: April 2021

Objective The aim of the study is to determine the relationship between a hospital's provision of subspecialty neonatal and maternal care. Specifically, we sought to understand where women with high-risk maternal conditions received intrapartum care and estimate the potential transfer burden for those with maternal high-risk conditions delivering at hospitals without subspecialty maternal care.

Study Design This is a descriptive study using data from 2015 State Inpatient Databases and the American Hospital Association Annual Survey. Characteristics were compared between hospitals based on the concordance of their maternal and neonatal care. The incidences of high-risk maternal conditions (pre-eclampsia with severe features, placenta previa with prior cesarean delivery, cardiac disease, pulmonary edema, and acute liver failure) were compared. To determine the potential referral burden, the percent of women with high-risk conditions delivering at a hospital without subspecialty maternal care but delivering in a county with a hospital with subspecialty maternal care was calculated.

Results The analysis included 486,398 women who delivered at 544 hospitals, of which 104 (19%) and 182 (33%) had subspecialty maternal and neonatal care, respectively. Ninety-eight hospitals provided both subspecialty maternal and neonatal care; however, 84 hospitals provided only subspecialty neonatal care but no subspecialty maternal care. Among high-risk maternal conditions examined, approximately 65% of women delivered at a hospital with subspecialty maternal care. Of the remainder who delivered at a hospital without subspecialty maternal care, one-third were in a county where subspecialty care was present. For women with high-risk conditions who delivered in a county without subspecialty maternal care, the median distance to the closest county with subspecialty care was 52.8 miles (IQR: 34.3–87.7 miles).

Conclusion Approximately 50% of hospitals with subspecialty neonatal care do not provide subspecialty maternal care. This discordance may present a challenge when both high-risk maternal and neonatal conditions are present.

Key Points
Expect the unexpected? Challenges of prospectively exploring stakeholder engagement in research
Authors: O’Shea Alison , Boaz Annette , Hanney Stephen , Kok Maarten , Borst Robert , Pokhrel Subhash , Jones Teresa
Published: April 2021

Stakeholder engagement in research is increasingly viewed as making a major contribution to assisting impact. This paper draws on a longitudinal, prospective impact study exploring stakeholder engagement in a 3-year tobacco control research project which used stakeholder engagement in the development, testing and dissemination of its return on investment tool. The paper presents the challenges of data collection when undertaking prospective research on stakeholder engagement in health-related research. The impact study used mixed methods of data collection to explore stakeholder engagement in the target project, comprising surveys, interviews and observations of meetings and events involving stakeholders. Stakeholder engagement that actually occurred in the target project, and the data collection methods of stakeholder engagement that were actually used in the impact study, varied substantially from those intended in each case. Data collection for the impact study was dependent on the target project’s stakeholder engagement, which became substantially reduced. Modifications to data collection for the impact study were required. One of the reasons for the reduction of stakeholder engagement was linked to constraints on the target project to meet non-negotiable deadlines. Another factor was concerns about overburdening stakeholders. The knock-on effect of reduced stakeholder engagement highlighted the impact study’s lack of control over its data collection, which was related to the prospective nature of the study. The authors acknowledge that an advantage of a retrospective approach over a prospective one is researchers knowing about data availability and accessibility from the outset. However, the prospective approach of the impact study enabled insight into stakeholder engagement in real-time: how and when it occurred, the challenges, and the experiences of stakeholders and the target project researchers. While the quantity of data gathered was considerably less than anticipated, the quality of data was rich and enabled the impact study objectives to be achieved. With increasing emphasis on public engagement in research and calls for engagement to be evaluated for impact, this paper aims—by highlighting the challenges the impact study experienced—to provide some insight to future research that seeks to respond to those calls.
Magnetic resonance imaging of calcium ions could unlock the brain’s mysteries
Authors: Johnson-Groh Mara
Published: April 2021

A review of magnetic resonance imaging of calcium ions presents the highlights and potentials of the technology.
Human eye movements follow a pattern similar to foraging by hunter-gatherers
Authors: Bandari Anashe
Published: April 2021

Models used to describe animal foraging behavior prove successful for modeling how we shift our gazes from object to object.
Laser polishing 3D metallic surfaces with an optical pre-shaping device leads to a constant surface quality
Authors: McConnon Aili
Published: April 2021

Keeping the laser beam geometry constant on a workpiece regardless of the angle of incidence shows promise.
The compatibility dimension of quantum measurements
Authors: Loulidi Faedi , Nechita Ion
Published: April 2021

We introduce the notion of compatibility dimension for a set of quantum measurements: it is the largest dimension of a Hilbert space on which the given measurements are compatible. In the Schrödinger picture, this notion corresponds to testing compatibility with ensembles of quantum states supported on a subspace, using the incompatibility witnesses of Carmeli, Heinosaari, and Toigo [Phys. Rev. A 98,012126 (2018) and Phys. Rev. Lett. 122, 130402 (2019).]. We provide several bounds for the compatibility dimension using approximate quantum cloning or algebraic techniques inspired by quantum error correction. We analyze in detail the case of two orthonormal bases and, in particular, that of mutually unbiased bases.
Boundary contributions to three loop superstring amplitudes
Authors: Bettadapura Kowshik , Lin Hai
Published: April 2021

In type II superstring theory, the vacuum amplitude at a given loop order g can receive contributions from the boundary of the compactified, genus g supermoduli space of curves M̄g. These contributions capture the long distance or infrared behavior of the amplitude. The boundary parameterizes degenerations of genus g super Riemann surfaces. A holomorphic projection of the supermoduli space onto its reduced space would then provide a way to integrate the holomorphic, superstring measure and thereby give the superstring vacuum amplitude at g-loop order. However, such a projection does not generally exist over the bulk of the supermoduli spaces in higher genera. Nevertheless, certain boundary divisors in ∂M̄g may holomorphically map onto a bosonic space upon composition with universal morphisms, thereby enabling an integration of the holomorphic, superstring measure here. Making use of ansatz factorizations of the superstring measure near the boundary, our analysis shows that the boundary contributions to the three loop vacuum amplitude will vanish in closed oriented type II superstring theory with unbroken spacetime supersymmetry.
Study of magnetic switch for surface plasmon-polariton circuits
Authors: Bile Alessandro , Pepino Ricardo , Fazio Eugenio
Published: April 2021

In recent years, technological development has focused on the construction of ever smaller devices, characterized by dimensions limited to the nanometer order and by a very low energy requirement to be able to function. This allows them to be integrated into chips, which are then able to perform many tasks from filtering to computation. Here, we present a magnetic switch capable of working with surface plasmon polaritons.
Calcium-responsive contrast agents for functional magnetic resonance imaging
Authors: Miller Austin D. C. , Ozbakir Harun F. , Mukherjee Arnab
Published: April 2021

Calcium ions represent one of the key second messengers accompanying neural activity and synaptic signaling. Accordingly, dynamic imaging of calcium fluctuations in living organisms represents a cornerstone technology for discovering neural mechanisms that underlie memory, determine behavior, and modulate emotional states as well as how these mechanisms are perturbed by neurological disease and brain injury. While optical technologies are well established for high resolution imaging of calcium dynamics, physical limits on light penetration hinder their application for whole-brain imaging in intact vertebrates. Unlike optics, magnetic resonance imaging (MRI) enables noninvasive large-scale imaging across vertebrates of all sizes. This has motivated the development of several sensors that leverage innovative physicochemical mechanisms to sensitize MRI contrast to intracellular and extracellular changes in calcium. Here, we review the current state-of-the-art in MRI-based calcium sensors, focusing on fundamental aspects of sensor performance, in vivo applications, and challenges related to sensitivity. We also highlight how innovations at the intersection of reporter gene technology and gene delivery open potential opportunities for mapping calcium activity in genetically targeted cells, complementing the benefits of small molecule probes and nanoparticle sensors.
A fast-reciprocating probe array for two-dimensional measurements in the divertor region of the Tokamak à configuration variable
Authors: De Oliveira H. , Theiler C. , Elaian H. ,   TCV Team
Published: April 2021

A detailed description of the construction and commissioning of the fast-moving reciprocating divertor Langmuir probe array on the Tokamak à Configuration Variable (TCV) is presented. A horizontal array of 24 Langmuir probes (12 Mach probes) combined with a fast vertical movement provides unprecedented two-dimensional measurements of the plasma properties across the entire divertor outer leg volume and up to the X-point. The L-shape probe arm has to be very compact to minimize plasma perturbations and, at the same time, has to house 24 coaxial transmission lines, withstand time-averaged heat fluxes of up to ≈30 MW/m2 and accelerations of up to 8 g, and be resilient to violent plasma disruptions. For the fast vertical motion of the probe arm, extending up to 38 cm into the TCV vacuum vessel, an assembly with a precise and powerful linear electric motor (up to 4000 N of force) was mounted in a 4 m high structure within the limited space below the TCV. The diagnostic has already performed measurements in ≈200 plasma discharges and has been hit by ≈20 disruptions without suffering any critical damage. The measurements are qualitatively and quantitatively consistent with other reference diagnostics, such as upstream electron Thomson scattering and downstream wall-embedded Langmuir probes, and are used extensively on the TCV for experimental divertor studies and for comparisons with edge transport and turbulence code results.
A general framework for multimode Gaussian quantum optics and photo-detection: Application to Hong–Ou–Mandel interference with filtered heralded single photon sources
Authors: Thomas Oliver F. , McCutcheon Will , McCutcheon Dara P. S.
Published: April 2021

The challenging requirements of large scale quantum information processing using parametric heralded single photon sources involve maximizing the interference visibility while maintaining an acceptable photon generation rate. By developing a general theoretical framework that allows us to include a large number of spatial and spectral modes together with linear and non-linear optical elements, we investigate the combined effects of spectral and photon number impurity on the measured Hong–Ou–Mandel interference visibility of parametric photon sources, considering both threshold and number resolving detectors, together with the effects of spectral filtering. We find that for any degree of spectral impurity, increasing the photon generation rate necessarily decreases the interference visibility, even when using number resolving detection. While tight spectral filtering can be used to enforce spectral purity and increased interference visibility at low powers, we find that the induced photon number impurity results in a decreasing interference visibility and heralding efficiency with pump power, while the maximum generation rate is also reduced.
Generation of B
y in Earth’s magnetotail with the effect of IMF B
y during southward interplanetary magnetic field
Authors: Li Lingjie
Published: April 2021

Based on the three-dimensional compressible resistive MHD models, the Earth’s dipole magnetic field is employed to investigate IMF By penetration driven by the solar wind during southward interplanetary magnetic field (IMF) with uniform resistivity. It is found that the magnetic field By is built up in the central plasma sheet of the Earth’s magnetotail. When θ = 30° (where BIMFy = BIMF  sin θ), the magnetic field By in the plasma sheet is the strongest and even larger than the initial imposed BIMFy. In addition, BIMFy promotes the reconnection process of dayside magnetopause. With a further increase in θ, the reconnection rate of dayside magnetopause and the magnetic field By decrease, and the structure changes significantly. The results can be used to analyze the observed data of IMF By penetration.
Realization of ultra-small stress birefringence detection with weak-value amplification technique
Authors: Wang Yongsheng , Chen Shizhen , Wen Shuangchun , Luo Hailu
Published: April 2021

How to realize the detection of tiny birefringence is an important but challenging issue for investigations and applications in optics. In weak measurements, weak-value amplification has been widely applied to the precise estimation of time delay. Here, we show that the linear amplification in weak measurements has the potential to outperform standard weak-value amplification for ultra-small parameter characterization. The higher measurement accuracy in the linear amplification enables us to achieve a measurement of stress-induced birefringence with a high resolution of 5×10−10. Compared with existing methods, the accuracy based on weak measurements for birefringence detection can improve two orders of magnitude. Our method may have important applications in a variety of fields involving the precise measurement of time delay or birefringence.
A study of Darcy–Bénard regular and chaotic convection using a new local thermal non-equilibrium formulation
Authors: Siddheshwar P. G. , Kanchana C. , Laroze D.
Published: April 2021

The onset of Darcy–Bénard regular and chaotic convection in a porous medium is studied by considering phase-lag effects that naturally arise in the thermal non-equilibrium heat transfer problem between the fluid and solid phases. A new type of heat equation is derived for both the phases. Using a double Fourier series and a novel decomposition, an extended Vadasz–Lorenz model with three phase-lag effects is derived. New parameters arise due to the phase-lag effects between local acceleration, convective acceleration, and thermal diffusion. The principle of exchange of stabilities is found to be valid and the subcritical instability is discounted. The new perspective supports the finding of an analytical expression for the critical Darcy–Rayleigh numbers representing, respectively, the onset of regular and chaotic convection. The understanding of the transition from the local thermal non-equilibrium situation to the local thermal equilibrium one is also best explained through the new perspective. In its present elegant form, the extended Vadasz–Lorenz system with three phase-lag effects is analyzed using the largest Lyapunov exponent and the bifurcation diagram. It is found that the lag effects not only give rise to a quantitative difference in the above two metrics concerning chaos, but also present a qualitative difference as well in the form of the very nature of chaos.
Band alignment and defects influence the electron–phonon heat transport mechanisms across metal interfaces
Authors: Olson David H. , Sales Maria G. , Tomko John A. , Lu Teng-Fei , Prezhdo Oleg V. , McDonnell Stephen J. , Hopkins Patrick E.
Published: April 2021

We report on the experimental determination of electron–electron conductance at Au/TiOx interfacial regions and electron–phonon coupling of thin TiOx layers for x = 0–2.62. Our study demonstrates that the electronic energy transport mechanisms at metal/metal oxide interfaces are enhanced through metallic defects that lead to electronic band alignment between the metal and metal oxide (in our case, Au and TiOx). Electronic heat transport processes are interrogated via a pump/probe technique, utilizing sub-picosecond laser pulses to monitor the ultrafast thermoreflectance responses of Au/TiOx systems, which were analyzed using a two-temperature model to extract electron–electron conductances at Au/TiOx interfaces and the electron–phonon coupling in TiOx layers. We find that TiOx stoichiometries near TiO2 have ultrahigh electron–phonon coupling factors similar to that of pure Ti and that electronic energy transmission from Au to TiOx layers is comparable to that of Au to Ti due to the presence of Ti0 defects. For x = 2.62 in TiOx, electron–phonon coupling is reduced by more than a factor of 5. Our experimental data are corroborated by real-time time-dependent density functional theory calculations, which show that excited electrons in Au do not participate in the TiOx phonon relaxation process, resulting in lower electron–electron energy transmission from Au and electron–phonon coupling due to the difference in the Fermi energy of Au relative to the conduction band minimum of TiOx when x >2.
Unitary coupled-cluster approach for the calculation of core-excited states and x-ray absorption spectra
Authors: Thielen Sebastian M. , Hodecker Manuel , Piazolo Julia , Rehn Dirk R. , Dreuw Andreas
Published: April 2021

In this work, we present the core–valence separation (CVS) approximation applied to unitary coupled-cluster (UCC) theory for the calculation of core-excited states and the simulation of x-ray absorption spectroscopy (XAS). Excitation energies and oscillator strengths of small- to medium-sized organic molecules have been computed using the second-order and extended second-order UCC schemes (CVS-UCC2 and CVS-UCC2-x) as well as the third-order scheme (CVS-UCC3). All results are compared to the corresponding algebraic-diagrammatic construction methods and experimental data. The agreement between CVS-UCC and experimental data demonstrates its potential as a new approach for the calculation of XAS.
Experimental and theoretical study on p-aminophenylthyil radical geminate recombination in ionic liquids; analysis using the Smoluchowski–Collins–Kimball equation
Authors: Fujii Kaori , Yagi Tomoaki , Nakano Hiroshi , Sato Hirofumi , Kimura Yoshifumi
Published: April 2021

Recombination dynamics of geminate p-aminophenylthiyl (PAPT) radicals produced from the photodissociation of bis(p-aminophenyl) disulfide in ionic liquids (ILs) were investigated by transient absorption spectroscopy. ILs with various cationic species were used to examine the effect of viscosity and polarity on recombination dynamics. Experimentally obtained recombination yields and dynamics were found to be virtually independent of the cation species, despite the viscosity range of the solvent ILs being extensive, spanning from a few tens of mPa s to several hundred mPa s. We applied a theoretical analysis model based on the diffusion equation to the time profiles of the experimentally determined recombination yields of geminate PAPT radicals. The square well potential was incorporated into the diffusion equation to consider the concerted dynamics of solvent cage formation and recombination. A long-time asymptotic expression for the survival probability of the photodissociated products was derived and used to simulate the experimentally obtained time profile of the recombination yield. The time profiles in the range of 20–1000 ps and the final yield were successfully simulated by the asymptotic expression of the square well potential model. The optimized parameters used for the fit, including the mutual diffusion coefficient of the radical pairs, cage radius of the potential well, and well depth, were discussed in terms of the diffusion coefficient conventional theory and the potential mean force estimated from the molecular dynamics simulation for the photodissociation reaction in ILs.
An ABC transporter Wzm–Wzt catalyzes translocation of lipid-linked galactan across the plasma membrane in mycobacteria
Authors: Savková Karin , Huszár Stanislav , Baráth Peter , Pakanová Zuzana , Kozmon Stanislav , Vancová Marie , Tesařová Martina , Blaško Jaroslav , Kaliňák Michal , Singh Vinayak , Korduláková Jana , Mikušová Katarína
Published: April 2021

Significance

The cell envelope of
Mycobacterium tuberculosis
serves as a primary protective barrier of the pathogen, which claims more than a million lives each year. Its basis, the unique mycobacterial cell wall core, is composed of covalently linked peptidoglycan, branched heteropolysaccharide arabinogalactan, and mycolic acids. Construction of this complex structure located on the bacterial surface requires an array of enzymes acting on both sides of the plasma membrane, as well as translocation of metabolic intermediates from the cytoplasm to the periplasmic space. In this work, we characterized an ATP-binding cassette (ABC) transporter involved in the export of galactan polymer produced by cytoplasmic enzymes across the plasma membrane, providing an important insight into the biogenesis of a structure critical for pathogen survival.
The JOREK non-linear extended MHD code and applications to large-scale instabilities and their control in magnetically confined fusion plasmas
Authors: Hoelzl M. , Huijsmans G.T.A. , Pamela S.J.P. , Bécoulet M. , Nardon E. , Artola F.J. , Nkonga B. , Atanasiu C.V. , Bandaru V. , Bhole A. , Bonfiglio D. , Cathey A. , Czarny O. , Dvornova A. , Fehér T. , Fil A. , Franck E. , Futatani S. , Gruca M. , Guillard H. , Haverkort J.W. , Holod I. , Hu D. , Kim S.K. , Korving S.Q. , Kos L. , Krebs I. , Kripner L. , Latu G. , Liu F. , Merkel P. , Meshcheriakov D. , Mitterauer V. , Mochalskyy S. , Morales J.A. , Nies R. , Nikulsin N. , Orain F. , Pratt J. , Ramasamy R. , Ramet P. , Reux C. , Särkimäki K. , Schwarz N. , Singh Verma P. , Smith S.F. , Sommariva C. , Strumberger E. , van Vugt D.C. , Verbeek M. , Westerhof E. , Wieschollek F. , Zielinski J.
Published: April 2021

JOREK is a massively parallel fully implicit non-linear extended magneto-hydrodynamic (MHD) code for realistic tokamak X-point plasmas. It has become a widely used versatile simulation code for studying large-scale plasma instabilities and their control and is continuously developed in an international community with strong involvements in the European fusion research programme and ITER organization. This article gives a comprehensive overview of the physics models implemented, numerical methods applied for solving the equations and physics studies performed with the code. A dedicated section highlights some of the verification work done for the code. A hierarchy of different physics models is available including a free boundary and resistive wall extension and hybrid kinetic-fluid models. The code allows for flux-surface aligned iso-parametric finite element grids in single and double X-point plasmas which can be extended to the true physical walls and uses a robust fully implicit time stepping. Particular focus is laid on plasma edge and scrape-off layer (SOL) physics as well as disruption related phenomena. Among the key results obtained with JOREK regarding plasma edge and SOL, are deep insights into the dynamics of edge localized modes (ELMs), ELM cycles, and ELM control by resonant magnetic perturbations, pellet injection, as well as by vertical magnetic kicks. Also ELM free regimes, detachment physics, the generation and transport of impurities during an ELM, and electrostatic turbulence in the pedestal region are investigated. Regarding disruptions, the focus is on the dynamics of the thermal quench (TQ) and current quench triggered by massive gas injection and shattered pellet injection, runaway electron (RE) dynamics as well as the RE interaction with MHD modes, and vertical displacement events. Also the seeding and suppression of tearing modes (TMs), the dynamics of naturally occurring TQs triggered by locked modes, and radiative collapses are being studied.
Construction and Applications of Stairboxplot for Exploratory Data Analysis
Authors: Babura Babangida Ibrahim , Adam Mohd Bakri , Sani Muhammad , Waziri Usman , Eguda Felix Yakubu
Published: April 2021

The classical construction of boxplot requires estimates of five robust statistics of interest namely, the first quartile, the median, the third quartile, the lower fence and the upper fence. The fence estimate is usually dependent on the three quartiles and is utilized to visually identify outliers in a batch of univariate dataset. Some scholars are critical of the limitation of boxplox to display individual data points, density of observations and distributional shape in multiple batch comparison among to mention. In this paper display enhancement to address the limitations of classical boxplot is proposed according to a new construction method called stairboxplot. The construction begins with display of four stairs of consecutive boxes according to quadbins to replace box and whiskers in the classical boxplot construction and an inscription of individual observations using scale adjusted outlyingness estimate of each data point. The advantage of stairboxplot as a data display toolkit was explored using simulation and real life dataset.
Experimental study of gas jet outflow from a supersonic nozzle with a screen into vacuum
Authors: Vyazov Y N , Prikhodko V G , Yarygin I V
Published: April 2021

The flow structure formed behind supersonic nozzle with a screen under joint outflow of gas and near-wall liquid film into vacuum is studied experimentally. Pressure in cavity between the nozzle and the screen is measured. Transversal pressure profiles in a jet behind the nozzle for different values of background gas pressure in the vacuum chamber are obtained. The significant effect of the screen on droplet phase flow structure behind the nozzle is shown.
Deposition of fluoropolymer coating on a metal mesh for manufacturing of oil-water emulsion separating membranes
Authors: Melnik A V , Petrova A V , Bogoslovtseva A L , Safonov A I
Published: April 2021

The membranes were synthesized by deposition of fluoropolymer coatings on metal meshes using the Hot Wire Chemical Vapor Deposition (HW CVD). The obtained membranes were used for the separation of an oil-water emulsion in a simple filtration facility. The main process parameters influencing the separation efficiency were determined and the optimal separation mode was selected. It was shown that the highest efficiency on the obtained membranes is achieved by separating emulsions containing water less 10%.
Gradient heatmetry in the study of boiling on spherical surface
Authors: Sapoznikov S Z , Mityakov V Yu , Pavlov A V , Bobylev P G , Vinogradov M D
Published: April 2021

The combination of methods of gradient heatmeatry and high-speed visualization made it possible to compare the distribution of the local heat flux and the hydrodynamics of the process during boiling of subcooled water on the surface of the sphere. The results are compared with the works of other authors and conclusions are drawn about the effect of subcooling of water on the intensity of heat transfer.
Experimental study of the plug flow of immiscible liquids with non-Newtonian properties in a T-shaped microchannel
Authors: Yagodnitsyna A A , Kovalev A V , Bilsky A V
Published: April 2021

The present paper aims to study the plug flow of immiscible liquids when the dispersed phase exhibits non-Newtonian properties. Plug formation regimes were studied both for the non-Newtonian dispersed phase case and three sets of Newtonian liquids with different viscosities. Plug length was measured and compared for various flow rates of the continuous and dispersed phases. It was shown that plug length could be dramatically increased by using non-Newtonian liquid as the dispersed phase.
An experimental investigation of the heat transfer dynamics during drop impact onto a liquid layer
Authors: Gigola T G , Cheverda V V , Karchevsky A L , Kabov O A
Published: April 2021

In the present work an experimental investigation of a drop impact onto a liquid layer of certain thickness placed on a heated thin foil is presented. The heat transfer and dynamics of drop impact on liquid surface has been studied and visualised with using infrared thermography. The experimental data obtained by means of an infrared scanner, that is, the measured temperature distributions on the opposite side of the foil will be used for the next stage of the research. The primary task of the research is to determine the heat flux from the foil by solving Cauchy problem for the non-stationary heat transfer equation that describes the heat conductivity inside the foil.
NORBY CubeSat nanosatellite: design challenges and the first flight data
Authors: Prokopyev V Yu , Bakanov S S , Bodrov V K , Chernodarov E N , Doroshkin A A , Gorev V N , Kolesnikova A Yu , Kozlov A S , Kus O. N. , Melkov A V , Mitrokhin A A , Morsin A A , Nazarenko A E , Neskorodev I V , Pelemeshko A V , Prokopyev Yu M , Romanov D A , Shilov A M , Shirokih M V , Sidorchuk A A , Styuf A S , Zadorozhny A M
Published: April 2021

The paper presents the NORBY 6U CubeSat nanosatellite’ launched on 28 September 2020 into a low-Earth orbit. The design of NORBY is briefly described’ the main characteristics of its subsystems are given’ and the results of the first flight tests are presented. The main features of the NORBY design are full hardware duplication of all subsystems and information interfaces’ as well as the use of LoRa modulation in radio communications between the satellite and a ground station. The first results of the NORBY flight tests confirm the effectiveness of the key technical solutions applied in the NORBY design. For the first time’ the operability of the LoRa modulation in satellite radio communications has been experimentally confirmed. The LoRa satellite-to-ground radio channel functioned sustainably at all tested parameters.
Micro-arc method for the synthesis of silicon nanostructures
Authors: Kaleeva A. A. , Timerkaev B. A. , Shamsutdinov R. S. , Saifutdinova A. A. , Shakirov B. R.
Published: April 2021

This paper presents the results of plasma synthesis of silicon nanostructures in an air-argon medium. The synthesis of silicon nanostructures was carried out in a vacuum chamber at a gas mixture pressure of 500 Torr, with partial pressures of argon and air in the ratio of 4:1. Molybdenum and silicon embedded in a copper tube were used as electrodes. Current and voltage were maintained in the range of 8-25 A and 30-50 V, corresponding. As a result of experiments, silicon nanostructures were deposited on the surface of the electrodes. Nanostructures were studied by optical and electron microscopes. Forms of silicon nanostructures were mainly in the form of nanotubes. Their diameters range from 200 nm to 500 nm, and their length reaches 1 mm. On the surface of these nanotubes, nanovilli with a diameter of about 5 nm and a length of 100 nm are observed.
Calculation of conditions for maintaining an ICRF-plasma using a self-consistent model
Authors: Zheltukhin V S , Terentev T N , Shemakhin A Y , Samsonova E S
Published: April 2021

The article proposes a new approach to calculating the strength of the magnetic field on the inner wall of the discharge chamber, which is necessary to maintain a steady state of a low-pressure ICRF discharge. The model is treate as a nonlinear eigenproblem. The influence of the third type boundary conditions for electron density as well as and the nonlinear boundary conditions for electrical strength is considered. This approach makes it possible solving two problems of designing ICRF plasma torches: for a given electron density in the discharge find the magnetic field strength that ensures the maintenance of the discharge, or, conversely, at a given magnetic field strength, determine the value of the electron density that can be created in the discharge. In addition, the radial distributions of the electric and magnetic fields and the electron concentration can be determined.