bluuebunny/crossref_metadata_2025 huggingface dataset:
Resilienz in klinischen Populationen
Authors: Berndt Christina , Pfennig Andrea
Published: April 2021

Resilienz beschreibt den Prozess der Aufrechterhaltung und/oder kurzfristigen Wiederherstellung von Gesundheit nach Exposition mit einem Stressor. Resilienzforschende sind mit einer Vielzahl von Definitionen, Operationalisierungen und Messverfahren in Resilienzstudien konfrontiert. Die Untersuchung von Resilienzfaktoren und -mechanismen in klinischen Populationen birgt methodische Herausforderungen, verspricht jedoch, das Verständnis für die Entwicklung, Manifestation und den Verlauf psychischer Störungen zu vertiefen.

Die Autorinnen diskutieren konzeptuelle Überlegungen und deren Implikationen für die Resilienzforschung in klinischen Populationen. Hier liegt der Fokus auf der Erfassung von Gesundheitsmarkern bereits vor Auftreten (spezifischer) Stressoren, um konzeptuelle Verlaufshypothesen in klinischen Populationen zu prüfen. In Zukunft sind prospektive, longitudinale Studien notwendig, welche die dynamischen und prozessualen Veränderungen psychischer Gesundheit in Reaktionen auf evidente Risikofaktoren und Stressoren abbilden und mittels innovativer Analysemethoden untersuchen. Empirisch gewonnene Ansätze für Prävention und Intervention werden die Erhaltung von Lebensqualität, Wohlbefinden, psychosozialem und beruflichem Funktionsvermögen angesichts psychischer Stressoren fokussieren.
Magnesium verbessert Vitamin-D-Konzentration bei älteren Hypertonikern
Authors: Kisters Klaus , Kisters Lukas , Werner Tanja Verena , Gröber Uwe
Published: April 2021

Magnesiummangel verursacht neben zahlreichen weiteren Symptomen über die Steigerung von Gefäßtonus und Gefäßreaktivität einen Blutdruckanstieg. Eine optimale Magnesiumversorgung kann zur Prävention kardiovaskulärer Erkrankungen beitragen. In einer Untersuchung an älteren Hypertonikern bewirkte eine Therapie mit täglich 400 mg Magnesiumcitrat neben der Blutdrucksenkung eine signifikante Verbesserung des Vitamin-D-Status.
COVID-19: Mit ω-3 die physiologische Resilienz steigern
Authors: Gröber Uwe
Published: April 2021

Ein Mangel an den ω-3-Fettsäuren Eicosapentaensäure und Docosahexaensäure betrifft weltweit über 1 Mrd. Menschen. EPA und DHA besitzen endothel-, epithel-, kardio- sowie neuroprotektive Eigenschaften und entfalten auf mehreren Ebenen positive Wirkungen im Infektionsgeschehen. Neben der Steigerung der Immunität u. a. durch erhöhte Bildung von Neutrophilen greifen sie in die Inflammation ein. Die Hemmung des NLRP3-Inflammosoms verhindert einen Zytokinsturm, der zu schwersten systemischen Entzündungen mit tödlichem Ausgang führen kann. Besonders aus DHA werden entzündungsauflösende Lipidmediatoren gebildet, die für die Beendigung von Entzündungen wichtig sind. Eine aktuelle Pilotstudie zeigt ein erhöhtes COVID-19-Sterberisiko bei niedrigem ω-3-Index.
Revising the European Society of Gastrointestinal Endoscopy (ESGE) research priorities: a research progress update
Authors: Bhandari Pradeep , Longcroft-Wheaton Gaius , Libanio Diogo , Pimentel-Nunes Pedro , Albeniz Eduardo , Pioche Mathieu , Sidhu Reena , Spada Cristiano , Anderloni Andrea , Repici Alessandro , Haidry Rehan , Barthet Marc , Neumann Helmut , Antonelli Giulio , Testoni Alberto , Ponchon Thierry , Siersema Peter D. , Fuccio Lorenzo , Hassan Cesare , Dinis-Ribeiro Mario
Published: April 2021

Background One of the aims of the European Society of Gastrointestinal Endoscopy (ESGE) is to encourage high quality endoscopic research at a European level. In 2016, the ESGE research committee published a set of research priorities. As endoscopic research is flourishing, we aimed to review the literature and determine whether endoscopic research over the last 4 years had managed to address any of our previously published priorities.

Methods As the previously published priorities were grouped under seven different domains, a working party with at least two European experts was created for each domain to review all the priorities under that domain. A structured review form was developed to standardize the review process. The group conducted an extensive literature search relevant to each of the priorities and then graded the priorities into three categories: (1) no longer a priority (well-designed trial, incorporated in national/international guidelines or adopted in routine clinical practice); (2) remains a priority (i. e. the above criterion was not met); (3) redefine the existing priority (i. e. the priority was too vague with the research question not clearly defined).

Results The previous ESGE research priorities document published in 2016 had 26 research priorities under seven domains. Our review of these priorities has resulted in seven priorities being removed from the list, one priority being partially removed, another seven being redefined to make them more precise, with eleven priorities remaining unchanged. This is a reflection of a rapid surge in endoscopic research, resulting in 27 % of research questions having already been answered and another 27 % requiring redefinition.

Conclusions Our extensive review process has led to the removal of seven research priorities from the previous (2016) list, leaving 19 research priorities that have been redefined to make them more precise and relevant for researchers and funding bodies to target.
Auswirkungen von COVID-19 auf nuklearmedizinische Untersuchungen und Therapien im Verlauf von 2020 – Ergebnisse einer nationalen Umfrage
Authors: Freudenberg Lutz S , Essler Markus , Herrmann Ken
Published: April 2021

Einleitung Die COVID-19-Pandemie stellt weltweit die Gesundheitssysteme vor eine in ihrem Ausmaß nicht zu erahnende Herausforderung. Diese Online-Umfrage erfasste die Auswirkungen der COVID-19-Pandemie auf die Leistungszahlen der Nuklearmedizin in Deutschland im Jahresvergleich 2020 zu 2019.

Materialien und Methoden Ein webbasierter Fragebogen wurde entwickelt, um die Leistungszahlen 2020 und insbesondere die Veränderungen im Jahresvergleich zu 2019 zu erfassen. Abgefragt wurden die Veränderungen in der nuklearmedizinischen Diagnostik und Therapie sowie inwieweit die Handlungsempfehlungen „Coronavirus SARS-CoV-2“ umgesetzt wurden.

Ergebnisse 91 vollständige Antworten wurden erfasst und ausgewertet, was rund 20 % aller deutschen nuklearmedizinischen Einrichtungen entspricht. In der Diagnostik zeigte sich im Vergleich zu 2019 eine Abnahme der Szintigrafien der Schilddrüse (15,9 %), der Knochen (8,8 %), der Lunge (7,6 %), der Sentinel-Lymphknoten (5,5 %) und des Myokards (1,4 %) bei geringem Anstieg der PET/CT-Untersuchungen (1,2 %). Bei den nuklearmedizinischen Therapien war die Reduktion bei den benignen Erkrankungen am höchsten (benigne Schilddrüse 13,3 %, RSO 7,7 %), während die Veränderungen zu 2019 bei den malignen Indikationen weniger ausgeprägt waren (PRRT + 2,2 %, PSMA + 7,4 %, SIRT –5,9 % und RJT bei Schilddrüsenkarzinom –2,4 %). Die Handlungsempfehlungen der DGN wurden zu 90 % ganz oder teilweise angewendet.

Schlussfolgerungen Die initial deutliche Reduktion der nuklearmedizinischen Leistungen in den ersten 3 Wochen der COVID-19-Pandemie hat sich im weiteren Verlauf nicht fortgesetzt, ein Nachholen der nicht durchgeführten Untersuchungen hat allerdings nicht stattgefunden. Besonders schwerwiegend war der Rückgang bei Diagnostik und Therapie der benignen Erkrankungen.
Sulfur Amino Acids: From Prebiotic Chemistry to Biology and Vice Versa
Authors: Vallée Yannick , Youssef-Saliba Sparta
Published: April 2021

Two sulfur-containing amino acids are included in the list of the 20 classical protein amino acids. A methionine residue is introduced at the start of the synthesis of all current proteins. Cysteine, thanks to its thiol function, plays an essential role in a very large number of catalytic sites. Here we present what is known about the prebiotic synthesis of these two amino acids and homocysteine, and we discuss their introduction into primitive peptides and more elaborate proteins.

1 Introduction

2 Sulfur Sources

3 Prebiotic Synthesis of Cysteine

4 Prebiotic Synthesis of Methionine

5 Homocysteine and Its Thiolactone

6 Methionine and Cystine in Proteins

7 Prebiotic Scenarios Using Sulfur Amino Acids

8 Introduction of Cys and Met in the Genetic Code

9 Conclusion
Chalcogenylation of Naphthalene Derivatives Catalyzed by Iron(III) Chloride and Potassium Iodide
Authors: Rampon Daniel S. , Seckler Diego , da Luz Eduardo Q. da , Silvério Gabriel L. , Badshah Gul , Lima David B. , Abreu Emerson A. , Albach Breidi , Ribeiro Ronny R.
Published: April 2021

We have developed an efficient chalcogenylation of electron-rich naphthalene derivatives catalyzed by FeCl3 and KI. The methodology provides access to several nonsymmetrical diorganoyl chalcogenides (S, Se) by selective C1 chalcogenylation of 2-naphthols or 2-naphthylamines using simple and cheap catalysts. Several control experiments supported the hypothesis that a redox reaction between Fe(III) and KI produces I2, which catalyzed the chalcogenylation.
Management Options for Suprasellar Cystic Craniopharyngioma: Endoscopic Transventricular Approach and Microsurgical Approach
Authors: Konar Subhas K. , Kulkarni Akshay V. , Shukla Dhaval , Misra Tejesh , Devi Bhagavatula Indira , Peer Sameer , Lanka Vivek
Published: April 2021

Objective The treatment of cystic craniopharyngioma in children is varied. The treatment ranges from radical excision to direct radiotherapy. As the morbidity of excision is high, more conservative approaches are used. Transventricular endoscopy is a minimally invasive treatment for cystic craniopharyngiomas. The objective of this study is to compare the outcome of microscopic versus endoscopic transventricular approach for cystic craniopharyngioma.

Methods This is a retrospective study of series of children managed with microscopic excision and endoscopic transventricular approach for suprasellar cystic craniopharyngiomas. Operative details, visual outcome, endocrinological outcome, tumor-related cyst recurrence rate, and complication were compared between microscopic and endoscopic groups.

Results A total of 28 children underwent microscopic excision and 14 children underwent endoscopic procedure. The anesthesia time was significantly lower with endoscopic as compared to microscopic group (p = 0.0001) as well as blood loss during surgery (p = 0.0001). Hospital stay after surgery was shorter in endoscopic group. Incidence of diabetes insipidus was more in microscopic group (25%) compared to endoscopic group (7.14%). Visual outcome was almost same with approaches. Requirement of hormone replacement was more in microscopic group than in endoscopic group (p = 0.006). Incidence of cyst recurrence was more in microscopic (39.3%) compared to endoscopic group (7.7%).

Conclusion Endoscopic transventricular approach is a safe alternative for initial treatment of suprasellar cystic craniopharyngioma in children.
Determinants of Mental Health Care Access in a Tribal District of Central India: Findings from a Health Camp
Authors: Sutar Roshan , Lahiri Anuja , Diwan Sanjeet , Satpathy Parmeshwar , Rozatkar Abhijit
Published: April 2021

Objective Mental health care needs of urban, rural, and tribal regions of India are varied and challenging, which require region-specific approaches. A significant treatment gap calls out for a state-wise introspection of existing service delivery models to cater to the specific mental health needs. In Madhya Pradesh, key findings were noted from a camp conducted in one of the tribal districts. To establish patient-centered services, it is important to understand their mental health care needs.

Materials and Methods A cross-sectional study within a mental health camp was conducted in the east-central tribal district of Madhya Pradesh by using a semi-structured interview.

Statistical Analysis Treatment deficit, pathways to care, and treatment barriers were assessed for correlation with demographic and clinical variables and analyzed by using the Chi-square test and logistic regression method using SPSS version 20.

Results Among 113 patients who sought help, treatment deficit was 85% with patient factors contributing 76% predominantly affecting the unmarried group of patients. Common mental illnesses (CMIs) outnumbered severe mental illnesses (SMIs) of which anxiety spectrum disorder contributed the most. SMIs still appear to remain undiagnosed till late in the course of illness. Nicotine dependence was higher in males (p < 0.001), and an increase in the dependence pattern was observed with increasing age (p = 0.001).

Conclusion Rising awareness and recognition of CMIs as a common mental health concern while under-recognition of SMIs among tribal communities needs further research. Considering attribution of symptoms to unknown factors, treatment barriers revolving around patient factors, and higher nicotine dependence in males, a timely evaluation of a multitargeted intervention to establish the balance in access to mental health care among the tribal population of Madhya Pradesh is warranted.
Global value chains, import orientation, and the state: South Africa’s pharmaceutical industry
Authors: Horner Rory
Published: April 2021

As opposed to the predominant focus of global value chain (GVC) research on export-oriented contexts, this article examines the prospects for development in places where the dominant form of engagement with GVCs is import-oriented. Through the case of South Africa’s pharmaceutical industry, this analysis demonstrates the challenge for local manufacturing to compete, and the associated state policy responses, in a place which is largely plugged into GVCs as an end market rather than as a production location. As multinationals have concentrated production elsewhere, South Africa’s manufacturing capacity in the pharmaceutical industry has relatively declined in recent decades. Having struggled in its facilitator role, the South African state’s efforts to promote local manufacturing have turned to the producer role through a state-owned company and especially the buyer role through public procurement. Motivations for state policy in this context, however, must navigate the tension which sometimes exists between the industrial interest in local manufacturing and the consumer and health policy interest in access to medicines. The experience of South Africa’s pharmaceutical industry points to the wider challenge and consequences of import-oriented engagement with GVCs for local industrial development.
Comparison of local and global gyrokinetic calculations of collisionless zonal flow damping in quasi-symmetric stellarators
Authors: Smoniewski J. , Sánchez E. , Calvo I. , Pueschel M. J. , Talmadge J. N.
Published: April 2021

The linear collisionless damping of zonal flows is calculated for quasi-symmetric stellarator equilibria in flux-tube, flux-surface, and full-volume geometry. Equilibria are studied from the quasi-helical symmetry configuration of the Helically Symmetric eXperiment (HSX), a broken symmetry configuration of HSX, and the quasi-axial symmetry geometry of the National Compact Stellarator eXperiment (NCSX). Zonal flow oscillations and long-time damping affect the zonal flow evolution, and the zonal flow residual goes to zero for small radial wavenumber. The oscillation frequency and damping rate depend on the bounce-averaged radial particle drift in accordance with theory. While each flux tube on a flux surface is unique, several different flux tubes in HSX or NCSX can reproduce the zonal flow damping from a flux-surface calculation given an adequate parallel extent. The flux-surface or flux-tube calculations can accurately reproduce the full-volume long-time residual for moderate kx, but the oscillation and damping time scales are longer in local representations, particularly for small kx approaching the system size.
Progressive RESET induced by Joule heating in hBN RRAMs
Authors: Zhuang Pingping , Ma Wenzhuang , Liu Jing , Cai Weiwei , Lin Weiyi
Published: April 2021

This Letter reports a progressive RESET operation in multilayer-hBN-based resistive random access memories (RRAMs) using Ti/hBN/Au as a prototype. An isotropic Joule heat effect governing the rupture of conductive filaments (CFs) is identified and then validated by a “re-SET” process, in which CFs are broken and reconnected under identically directional electrical fields. SET operations cannot be achieved if the device is incompletely RESET. This progressive switching behavior differs from multi-state memristors' counterparts and, thus, should be ruled out from RRAMs in binary systems. The study of progressively one-by-one rupture of CFs serves as a more comprehensive understanding of the resistive switching mechanism of hBN RRAMs and could facilitate the investigation of practical applications of 2D RRAMs.
Dispersion in dielectric-lined waveguides designed for terahertz-driven deflection of electron beams
Authors: Georgiadis V. , Healy A. L. , Hibberd M. T. , Burt G. , Jamison S. P. , Graham D. M.
Published: April 2021

We have developed dielectric-lined rectangular waveguide structures for terahertz (THz)-driven ultrafast deflection of 100 keV electron beams. The structures were designed to achieve THz phase velocity matching with co-propagating electron bunches. The phase-matching capability was experimentally confirmed through time-frequency analysis of the broadband coherent THz transmission measured by electro-optic sampling. The analysis determined both the frequency-dependent propagation constants in the electron interaction region and the propagation characteristics of the integrated THz tapered coupler.
Single- and dual-mode Rayleigh–Taylor instability at microscopic scale
Authors: Ding Juchun , Sun Pengyue , Huang Shenghong , Luo Xisheng
Published: April 2021

The microscopic Rayleigh–Taylor instability (RTI) is studied via molecular dynamics (MD) simulation for single- and dual-mode interfaces under a strong acceleration. The growth behavior of microscopic RTI as well as the underlying regime exhibits considerable differences from the macroscopic counterpart. At a microscopic scale, the flow Reynolds number is very low and thus viscosity effect plays an important role, namely, it suppresses the growth of overall perturbation amplitude and also damps the growth of harmonics. As a result, the microscopic RTI presents a much weaker nonlinearity. Also, the motion of atoms produces random fluctuations to the evolving interface, which cause the detachment of droplets from the spike under the action of surface tension at late stages. In addition, the mode coupling behavior in dual-mode RTI at a microscopic scale is evidently different from the macroscopic counterpart, and a new prescription dominating the growth of each mode is proposed. Based on these findings, a semi-empirical model applicable to the microscopic RTI from early to late stages is developed, which gives a satisfactory prediction of the MD results.
Giant magnetoelectric effect in an L21-ordered Co2FeSi/Pb(Mg1/3Nb2/3)O3-PbTiO3 multiferroic heterostructure
Authors: Usami T. , Fujii S. , Yamada S. , Shiratsuchi Y. , Nakatani R. , Hamaya K.
Published: April 2021

We experimentally show a giant magnetoelectric (ME) effect at room temperature in an interfacial multiferroic heterostructure consisting of L21-ordered Co2FeSi and Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT). Molecular beam epitaxy growth at 400 °C enables us to obtain epitaxial and L21-ordered Co2FeSi films on PMN-PT(001). For the epitaxial Co2FeSi/PMN-PT heterostructure, the remanent magnetization state can be largely modulated by varying electric fields. We note that the room-temperature ME coupling coefficient (α) is estimated to be 6.0–6.3 ×10−6 s/m, comparable to the highest α value reported previously. Nonvolatile and repeatable magnetization changes in remanent states are also demonstrated. These results will pave the way for room-temperature electric-field control of the magnetization of half-metallic Heusler alloys in high-performance spintronic devices.
Deterioration of the piezoelectric properties of (Bi0.5Na0.5)TiO3 when using Na2CO3 as a sintering aid: A crystallographic and microstructural study
Authors: Mahon Tadhg , Giannopoulos Dimosthenis , van der Zwaag Sybrand , Groen Pim
Published: April 2021

In this work, we present the impact of using Na2CO3 as a sintering aid and grain growth agent on the crystal structure, microstructure, and piezoelectric properties of (Bi0.5Na0.5)TiO3 ceramics. The addition of Na2CO3 leads to a substantial increase in the grain size and density even at a reduced sintering temperature of 1025 °C. However, at the same time, the value of the piezoelectric constant d33 drops dramatically. Using high-resolution x-ray diffraction analysis, we demonstrate that the decrease in piezoelectric constant is due to a change in the chemical composition of the (Bi0.5Na0.5)TiO3 base material rather than due to the change in the grain size. High Na2CO3-addition levels lead to the formation of Bi2O3 as a secondary phase during sintering too.
Narrow inhomogeneous distribution of spin-active emitters in silicon carbide
Authors: Nagy Roland , Dasari Durga Bhaktavatsala Rao , Babin Charles , Liu Di , Vorobyov Vadim , Niethammer Matthias , Widmann Matthias , Linkewitz Tobias , Gediz Izel , Stöhr Rainer , Weber Heiko B. , Ohshima Takeshi , Ghezellou Misagh , Son Nguyen Tien , Ul-Hassan Jawad , Kaiser Florian , Wrachtrup Jörg
Published: April 2021

Optically active solid-state spin registers have demonstrated their unique potential in quantum computing, communication, and sensing. Realizing scalability and increasing application complexity require entangling multiple individual systems, e.g., via photon interference in an optical network. However, most solid-state emitters show relatively broad spectral distributions, which hinders optical interference experiments. Here, we demonstrate that silicon vacancy centers in semiconductor silicon carbide (SiC) provide a remarkably small natural distribution of their optical absorption/emission lines despite an elevated defect concentration of ≈0.43 μm−3. In particular, without any external tuning mechanism, we show that only 13 defects have to be investigated until at least two optical lines overlap within the lifetime-limited linewidth. Moreover, we identify emitters with overlapping emission profiles within diffraction-limited excitation spots, for which we introduce simplified schemes for the generation of computationally relevant Greenberger–Horne–Zeilinger and cluster states. Our results underline the potential of the CMOS-compatible SiC platform toward realizing networked quantum technology applications.
Generation of reproductively mature offspring from the endangered green and golden bell frog
Authors: Upton Rose , Clulow Simon , Calatayud Natalie E. , Colyvas Kim , Seeto Rebecca G. Y. , Wong Lesley A. M. , Mahony Michael J. , Clulow John
Published: April 2021

Amphibians are becoming increasingly reliant on captive breeding programs for continued survival. Assisted reproductive technologies including gamete cryopreservation and IVF can help reduce costs of breeding programs, provide insurance against extinction and assist genetic rescue in wild populations. However, the use of these technologies to produce reproductively mature offspring has only been demonstrated in a few non-model species. We aimed to optimise sperm cryopreservation in the threatened frog Litoria aurea and generate mature offspring from frozen–thawed spermatozoa by IVF. We tested three concentrations (1.4, 2.1 and 2.8 M) of the cryoprotectants dimethylsulfoxide (DMSO) and glycerol with 0.3 M sucrose. Using DMSO was more likely to result in recovery of sperm motility, vitality and acrosome integrity than glycerol, regardless of concentration, with forward progressive motility being most sensitive to damage. The lowest concentrations of 1.4 and 2.1 M provided the best protection regardless of cryoprotectant type. Spermatozoa cryopreserved in 2.1 M DMSO outperformed spermatozoa cryopreserved in equivalent concentrations of glycerol in terms of their ability to fertilise ova, resulting in higher rates of embryos hatching and several individuals reaching sexual maturity. We have demonstrated that sperm cryopreservation and subsequent offspring generation via IVF is a feasible conservation tool for L. aurea and other threatened amphibians.
EPH/EPHRIN regulates cellular organization by actomyosin contractility effects on cell contacts
Authors: Kindberg Abigail A. , Srivastava Vasudha , Muncie Jonathon M. , Weaver Valerie M. , Gartner Zev J. , Bush Jeffrey O.
Published: April 2021

EPH/EPHRIN signaling is essential to many aspects of tissue self-organization and morphogenesis, but little is known about how EPH/EPHRIN signaling regulates cell mechanics during these processes. Here, we use a series of approaches to examine how EPH/EPHRIN signaling drives cellular self-organization. Contact angle measurements reveal that EPH/EPHRIN signaling decreases the stability of heterotypic cell:cell contacts through increased cortical actomyosin contractility. We find that EPH/EPHRIN-driven cell segregation depends on actomyosin contractility but occurs independently of directed cell migration and without changes in cell adhesion. Atomic force microscopy and live cell imaging of myosin localization support that EPH/EPHRIN signaling results in increased cortical tension. Interestingly, actomyosin contractility also nonautonomously drives increased EPHB2:EPHB2 homotypic contacts. Finally, we demonstrate that changes in tissue organization are driven by minimization of heterotypic contacts through actomyosin contractility in cell aggregates and by mouse genetics experiments. These data elucidate the biomechanical mechanisms driving EPH/EPHRIN-based cell segregation wherein differences in interfacial tension, regulated by actomyosin contractility, govern cellular self-organization.
On the geometry of Petrov type II spacetimes
Authors: Aksteiner Steffen , Andersson Lars , Araneda Bernardo , Whiting Bernard
Published: April 2021

In general, geometries of Petrov type II do not admit symmetries in terms of Killing vectors or spinors. We introduce a weaker form of Killing equations which do admit solutions. In particular, there is an analog of the Penrose–Walker Killing spinor. Some of its properties, including associated conservation laws, are discussed. Perturbations of Petrov type II Einstein geometries in terms of a complex scalar Debye potential yield complex solutions to the linearized Einstein equations. The complex linearized Weyl tensor is shown to be half Petrov type N. The remaining curvature component on the algebraically special side is reduced to a first order differential operator acting on the potential.
Two photon pumped nanowire laser based on all inorganic perovskite with high exciton binding energy grown by physical vapor deposition
Authors: Sun Mingfei , Wang Jian , Li Qicong , Jia Xiaohao , Huang Zhitao , Sun Jiaqian , Chu Kaiwen , Liu Kong , Jin Peng , Wang Zhijie , Qu Shengchun
Published: April 2021

Cesium lead halide (CsPbBr3) perovskite nanomaterials exhibit attractive optical properties, particularly in higher nonlinear optical effects and larger multiphoton absorption efficiency, compared with conventional semiconductors. The unique feature of stable lasing action under photon pumping conditions grants such materials great potential in photonics. Herein, through an in-depth study of the growing mechanism, all-inorganic perovskite nanomaterials with a high crystalline quality and tunable morphologies were synthesized, by a modified physical vapor deposition procedure. The prepared nanowire laser not only presents a high-performance laser output under single-photon pumping conditions, but also maintains decent behavior under two-photon pumping conditions. Importantly, the temperature-dependent fluorescence spectroscopy test of the nanowires reveals that the high exciton binding energy, twice as large as the thermal disturbance at room temperature, is the dominant reason for maintaining stable lasing under high energy density injection conditions.
Mid-infrared adaptive thermal camouflage using a phase-change material coupled dielectric nanoantenna
Authors: Buhara Ebru , Ghobadi Amir , Khalichi Bahram , Kocer Hasan , Ozbay Ekmel
Published: April 2021

Recently, camouflage technology has attracted researchers’ attention in a large variety of thermal applications. As a special phase change material (PCM), vanadium dioxide (VO2) is an excellent candidate for the studies conducted on thermal camouflage technology. VO2 has a transition from the insulator phase to the metal phase with the increase of the temperature. With regards to this unique feature, VO2 can contribute dynamic properties to the camouflage design. In this paper, a PCM–dielectric based metamaterial mid-infrared adaptive thermal camouflage nanoantenna is designed to perfectly mimic the atmospheric windows. The adaptive property of the proposed structure is obtained by using an ultrathin VO2 interlayer embedded within the grating. The spectral responses of the structure are computed using the finite difference time domain method, and the invisibility of the structure is proved using power calculations in the different mid-infrared regions.
Magnetoelectric control of antiferromagnetic domain state in Cr2O3 thin film
Authors: Shiratsuchi Yu , Toyoki Kentaro , Nakatani Ryoichi
Published: April 2021

Magnetoelectric (ME) effect is a type of cross-coupling between unconjugated physical quantities, such as the interplay between magnetization and electric field. The ME effect requires simultaneous breaking of spatial and time inversion symmetries, and it sometimes appears in specific antiferromagnetic (AFM) insulators. In recent years, there has been a growing interest for applying the ME effect to spintronic devices, where the effect is utilized as an input method for the digital information. In this article, we review the recent progress of this scheme mainly based on our own achievements. We particularly focus on several fundamental issues, including the ME control of the AFM domain state, which is detectable through the perpendicular exchange bias polarity. The progress made in understanding the switching mechanism, interpretation of the switching energy, switching dynamics, and finally, the future prospects are included.
Lung cancer risk and effective dose coefficients for radon: UNSCEAR review and ICRP conclusions
Authors: Harrison J D
Published: April 2021

The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has provided a detailed and authoritative update of its reviews of the epidemiology and dosimetry of radon and progeny. Lifetime risk of lung cancer calculated using data for several miner cohorts were 2.4–7.5 × 10−4 per working level month (WLM) of radon-222 progeny exposure for a mixed male/female population and 3.0–9.6 × 10−4 per WLM for a male population. Dosimetric models gave mean values of effective dose coefficients from radon-222 progeny of 12 mSv per WLM for mines, 16 mSv per WLM for indoor workplaces and 11 mSv per WLM for homes. The lifetime risk coefficient used by the International Commission on Radiological Protection (ICRP) is 5 × 10−4 per WLM and it has recently recommended an effective dose coefficient for radon-222 and progeny of 3 mSv per mJ h m−3 (about 10 mSv per WLM) for most circumstances of exposure. The ICRP risk and dose coefficients are supported by the UNSCEAR review and provide a clear and firm basis for current international advice and standards for protection from radon. Notwithstanding this evidence and the ICRP advice, UNSCEAR will continue to use a lower value of effective dose coefficient of 5.7 mSv per WLM for assessments of population exposures.
Resistive pulse sensing device with embedded nanochannel (nanochannel-RPS) for label-free biomolecule and bionanoparticle analysis
Authors: Han Ziyu , Liu Jiantao , Liu Zhanning , Pan Wenwei , Yang Yang , Chen Xuejiao , Gao Yunhua , Duan Xuexin
Published: April 2021

This paper reports an IC-compatible method for fabricating a PDMS-based resistive pulse sensing (RPS) device with embedded nanochannel (nanochannel-RPS) for label-free analysis of biomolecules and bionanoparticles, such as plasmid DNAs and exosomes. Here, a multilayer lithography process was proposed to fabricate the PDMS mold for the microfluidic device, comprising a bridging nanochannel, as the sensing gate. RPS was performed by placing the sensing and excitation electrodes symmetrically upstream and downstream of the sensing gate. In order to reduce the noise level, a reference electrode was designed and placed beside the excitation electrode. To demonstrate the feasibility of the proposed nanochannel-RPS device and sensing system, polystyrene micro- and nanoparticles with diameters of 1μm and 300 nm were tested by the proposed device with signal-to-noise ratios (SNR) ranging from 9.1–30.5 and 2.2–5.9, respectively. Furthermore, a nanochannel with height of 300 nm was applied for 4 kb plasmid DNA detection, implying the potential of the proposed method for label-free quantification of nanoscale biomolecules. Moreover, HeLa cell exosomes, known as a well-studied subtype of extracellular vesicles, were measured and analyzed by their size distribution. The result of the resistive pulse amplitude corresponded well to that of nanoparticle tracking analysis (NTA). The proposed nanochannel-RPS device and the sensing strategy are not only capable of label-free analysis for nanoscale biomolecules and bionanoparticles, but are also cost-effective for large-scale manufacturing.
Investigation of the effect of acquisition schemes on time-resolved magnetic resonance fingerprinting
Authors: Li Tian , Cui Di , Ren Ge , Hui Edward S , Cai Jing
Published: April 2021

Purpose. This study aims to investigate the feasibility of different acquisition methods for time-resolved magnetic resonance fingerprinting (TR-MRF) in computer simulation. Methods. An extended cardiac-torso (XCAT) phantom is used to generate abdominal T1, T2, and proton density maps for MRF simulation. The simulated MRF technique consists of an IR-FISP MRF sequence with spiral trajectory acquisition. MRF maps were simulated with different numbers of repetitions from 1 to 15. Three different methods were used to generate TR-MRF maps: (1) continuous acquisition without delay between MRF repetitions; (2) continuous acquisition with 5 s delay between MRF repetitions; (3) triggered acquisition with variable delay between MRF repetitions to allow the next acquisition to start at different respiration phase. After the generation of TR-MRF maps, the image quality indexes including the absolute T1 and T2 values, signal-to-noise-ratio (SNR), tumor-to-liver contrast-to-noise ratio, error in the amplitude of diaphragm motion and tumor volume error were used to evaluate the reconstructed parameter maps. Three volunteers were recruited to test the feasibility of the selected acquisition method. Results. Dynamic MR parametric maps using three different acquisition methods were estimated. The overall and liver T1 value error, liver SNR in T1 and T2 maps, and tumor SNR from T1 maps from triggered method is statistically significantly better than the other two methods (p-value < 0.05). The other image quality indexes have no significant difference between the triggered method and the other two continuous acquisition methods. All image quality indexes exhibit no significant difference between the acquisition methods with 0 s and 5 s delay. The triggered method was successfully performed in three healthy volunteers. Conclusion. TR-MRF technique was investigated using three different acquisition methods in computer simulation where the triggered method showed better performance than the other two methods. The triggered method has been tested successfully in healthy volunteers.
Quasilinear treatment of wave–particle interactions in the electron cyclotron range and its implementation in a gyrokinetic code
Authors: Donnel P , Cazabonne J , Villard L , Brunner S , Coda S , Decker J , Murugappan M , Sadr M
Published: April 2021

A quasilinear operator for wave–particle interactions in the electron cyclotron range is derived using the cold plasma dispersion relation. The finite width of the beam implies a broadening of the resonance layer in the velocity space which allows the use of a numerically efficient treatment of the operator. The specific case of a pure heating injected at the outer mid-plane is then treated. It allows to treat the beam propagation and absorption easily, simplifying the implementation of the source term in the gyrokinetic code. This specific case is implemented in the gyrokinetic particle-in-cell code ORB5 using a Langevin approach. The derivation and verification of the source operator are presented.
Overview of the isotope effects in the ASDEX Upgrade tokamak
Authors: Schneider P A , Hennequin P , Bonanomi N , Dunne M , Conway G D , Plank U
Published: April 2021

In recent years, measurements on the ASDEX Upgrade tokamak and modelling performed for plasmas with hydrogen (H) and deuterium (D) as the main gas have improved our understanding of the ion mass dependencies in fusion plasmas. The observed isotope effects can be explained with established physics processes which highlight the importance of treating heat transport with coupled electron and ion heat channels. In the core of electron heated L-mode plasmas, the mass dependence of the electron–ion equipartition results in a reduction of

q

i

/

q

e

with increasing ion mass. Combined with higher profile stiffness in the ions compared to the electrons, this results in improved core confinement for higher ion masses. At the edge of L-mode plasmas where a higher collisionality is observed, parallel electron dynamics is fundamental for turbulence. The parallel electron dynamics term in the gyrokinetic equations directly depends on

m

i

/

m

e

, resulting in a different kinetic response with different ion mass. Higher turbulent fluxes are expected with lower ion mass. This is consistent with the difference in

L

n

e

observed in the experiment. The mass dependence of turbulent transport in the L-mode edge has direct consequences for the L–H transition. More heating power is required to enter the H-mode at lower mass (

P

L-H

H

∼
2

P

L-H

D

). This is expected if the critical E × B shearing rate

γ

E
×
B

is important for the transition from L to H mode. In the H-mode pedestal,

γ

E
×
B

remains important to regulate the turbulent transport. The electrons do not contribute to

γ

E
×
B

and the enhanced equipartition for lower ion masses causes a shift from the ion channel to the electron channel in the absolute heat fluxes. Consequently, the inter edge localised mode (ELM) transport is found to be higher with lower isotope mass. This enhanced transport in H can prevent the pedestal from reaching the peeling–ballooning stability boundary with engineering parameters where D plasmas are peeling–ballooning unstable. Increasing the triangularity reduces the inter ELM transport in H stronger than in comparable D plasmas. For matched pedestal top and matched heat sources, the core heat transport is found to be similar for H and D when the fast-ion content is low. When ion temperature gradient turbulence stabilisation by fast ions becomes relevant, the mass dependent fast-ion slowing down results in higher fast-ion content in D and therefore in a reduction of ion heat transport in the core. Then, even for matched pedestals

τ

E

D

>

τ

E

H

.
Improvement of the first flux entry field by laser post-treatment of the thin Nb film on Cu
Authors: Ries R , Seiler E , Gömöry F , Medvids A , Onufrijevs P , Pira C , Chyhyrynets E , Malyshev O B , Valizadeh R
Published: April 2021

In superconducting radiofrequency accelerating cavities for particle accelerators, the Nb/Cu structure is one of the alternatives to bulk Nb but R&D is required to achieve a reproducible performance that competes with bulk Nb. The DC entry field H
en and critical temperature were studied in the thin Nb films deposited by magnetron sputtering on Cu substrate. The Nb surfaces were further treated by Nd:YAG laser at four energy doses (D1 = 350, D2 = 233, D3 = 175 and D4 = 140 J cm−2). The superconducting properties and other characteristics obtained by atomic force microscope, scanning electron microscope and x-ray diffraction were compared before and after laser treatment. The laser treatment increased the field of first flux entry by up to 65% compared to a non-irradiated sample. The laser irradiation also led to reduction of surface roughness, improvement of the surface morphology, reduction in crystallite size and increase of lattice parameter.
Quench and self-protecting behaviour of an intra-layer no-insulation (LNI) REBCO coil at 31.4 T
Authors: Suetomi Y , Yoshida T , Takahashi S , Takao T , Nishijima G , Kitaguchi H , Miyoshi Y , Hamada M , Saito K , Piao R , Takeda Y , Maeda H , Yanagisawa Y
Published: April 2021

This paper presents experimental results on a quench of an intra-layer no-insulation (LNI) (RE: rare earth)Ba2Cu3O7−δ
(REBCO) coil in a 31.4 T central magnetic field and simulated results on the quench. We have been designing a persistent-mode 1.3 GHz (30.5 T) nuclear magnetic resonance (NMR) magnet with a layer-wound REBCO inner coil. Protection of the REBCO coil from quench is a significant issue and the coil employs the LNI method to obtain self-protecting characteristics. We conducted high-field generation and quench experiments on an LNI-REBCO coil connected to an insulated Bi2Sr2Ca2Cu3O
x
(Bi-2223) coil under a background magnetic field of 17.2 T as a model of the 1.3 GHz NMR magnet. The coils successfully generated a central magnetic field of 31.4 T. Although the LNI-REBCO coil quenched at 31.4 T, this quench did not cause any degradation to the coil. A numerical simulation showed the current distribution during the quench was non-uniform and changed rapidly over time due to current bypassing through copper sheets between layers, resulting in faster quench propagation than in an insulated REBCO coil. During the quench propagation, the peak temperature (T
peak) and the peak hoop stress BzJR (σθ,

peak) were calculated to be 330 K and 718 MPa, respectively. These are below critical values that cause degradation. The simulation also showed that the high electrical contact resistivity (ρ
ct) of 10 000 µΩ cm2, between REBCO conductors and copper sheets in the LNI-REBCO coil winding, played an important role in protection. When ρ
ct was as low as 70 µΩ cm2, the quench propagation became too fast and large additional currents were induced, resulting in an extremely high σθ,

peak of 1398 MPa, while the T
peak was as low as 75 K. In short, the high ρ
ct in the present coil caused a high T
peak, but succeeded in suppressing σθ,

peak and protecting the coil from the quench.
Practical limits of error correction for quantum metrology
Authors: Shettell Nathan , Munro William J , Markham Damian , Nemoto Kae
Published: April 2021

Noise is the greatest obstacle in quantum metrology that limits it achievable precision and sensitivity. There are many techniques to mitigate the effect of noise, but this can never be done completely. One commonly proposed technique is to repeatedly apply quantum error correction. Unfortunately, the required repetition frequency needed to recover the Heisenberg limit is unachievable with the existing quantum technologies. In this article we explore the discrete application of quantum error correction with current technological limitations in mind. We establish that quantum error correction can be beneficial and highlight the factors which need to be improved so one can reliably reach the Heisenberg limit level precision.
Cavity magnomechanical storage and retrieval of quantum states
Authors: Sarma Bijita , Busch Thomas , Twamley Jason
Published: April 2021

We show how a quantum state in a microwave cavity mode can be transferred to and stored in a phononic mode via an intermediate magnon mode in a magnomechanical system. For this we consider a ferrimagnetic yttrium iron garnet (YIG) sphere inserted in a microwave cavity, where the microwave and magnon modes are coupled via a magnetic-dipole interaction and the magnon and phonon modes in the YIG sphere are coupled via magnetostrictive forces. By modulating the cavity and magnon detunings and the driving of the magnon mode in time, a stimulated Raman adiabatic passage-like coherent transfer becomes possible between the cavity mode and the phonon mode. The phononic mode can be used to store the photonic quantum state for long periods as it possesses lower damping than the photonic and magnon modes. Thus our proposed scheme offers a possibility of using magnomechanical systems as quantum memory for photonic quantum information.
High sensitive, linear and thermostable pressure sensor utilizing bipolar junction transistor for 5 kPa
Authors: Basov Mikhail
Published: April 2021

Research of pressure sensor chip utilizing novel electrical circuit with bipolar-junction transistor-based (BJT) piezosensitive differential amplifier with negative feedback loop (PDA-NFL) for 5 kPa differential range was done. The significant advantages of developed chip PDA-NFL in the comparative analysis of advanced pressure sensor analogs, which are using the Wheatstone piezoresistive bridge, are clearly shown. The experimental results prove that pressure sensor chip PDA-NFL with 4.0 × 4.0 mm2 chip area has sensitivity S = 11.2 ± 1.8 mV/V/kPa with nonlinearity of 2KNLback = 0.11 ± 0.09%/FS (pressure is applied from the back side of pressure sensor chip) and 2KNLtop = 0.18 ± 0.09%/FS (pressure is applied from the top side of pressure sensor chip). All temperature characteristics have low errors, because the precision elements balance of PDA-NFL electric circuit was used. Additionally, the burst pressure is 80 times higher than the working range.
A memristive map with coexisting chaos and hyperchaos*
Authors: Kong Sixiao , Li Chunbiao , He Shaobo , Çiçek Serdar , Lai Qiang
Published: April 2021

By introducing a discrete memristor and periodic sinusoidal functions, a two-dimensional map with coexisting chaos and hyperchaos is constructed. Various coexisting chaotic and hyperchaotic attractors under different Lyapunov exponents are firstly found in this discrete map, along with which other regimes of coexistence such as coexisting chaos, quasi-periodic oscillation, and discrete periodic points are also captured. The hyperchaotic attractors can be flexibly controlled to be unipolar or bipolar by newly embedded constants meanwhile the amplitude can also be controlled in combination with those coexisting attractors. Based on the nonlinear auto-regressive model with exogenous inputs (NARX) for neural network, the dynamics of the memristive map is well predicted, which provides a potential passage in artificial intelligence-based applications.
Fewer deep cyclones projected for the midlatitudes in a warming climate, but with more intense rainfall
Authors: Pepler Acacia , Dowdy Andrew
Published: April 2021

Cyclones are a major cause of extreme weather in the extratropics. Projections of future climate change have focussed on extratropical cyclones identified close to the surface, but cyclones identified at multiple levels of the atmosphere (‘deep’ cyclones) make the largest contributions to total and extreme rainfall. Here we use ten CMIP5 models to assess projected changes in cyclone frequency and associated heavy rainfall between 1979–2005 and 2070–2099 under a high emissions scenario (RCP8.5), with a focus on changes in vertically organised (‘deep’) systems with cyclones present at both the surface and 500 hPa. We find a robust decrease in the number of deep cyclones by the end of the 21st century, together with an increase in the number of extreme rainfall events caused by deep cyclones. In contrast to deep cyclones, shallow cyclones identified only at the surface are found to produce less rain and are projected to increase in frequency in the future, particularly over land areas. Our findings demonstrate the benefits of considering vertically deep cyclones, as their connection to extreme rainfall has implications for risk assessment and climate adaptation strategies.