bluuebunny/crossref_metadata_2025 huggingface dataset:
An iron oxyborate Fe3BO5material as a high-performance anode for lithium-ion and sodium-ion batteries
Authors: Ping Qiushi , Xu Beibei , Ma Xiao , Tian Jianliya , Wang Baofeng
Published: April 2019

The surface pseudocapacitance contribution is dominant in Na+storage processes in favour of the high rate performance of Fe3BO5.
The influence of metal-complexing macrocycle size on intramolecular movement in rotaxanes
Authors: Woźny Mateusz , Tomczyk Karolina M. , Więckowska Agnieszka , Sutuła Szymon , Trzybiński Damian , Woźniak Krzysztof , Korybut-Daszkiewicz Bohdan
Published: April 2019

New [2]rotaxanes composed of dibenzo-24-crown-8 wheel and the axle containing two metal-complexing 14- and/or 16-membered tetraazamacrocyclic units, coordinating the same or different metal ions (Ni and/or Cu) were synthesized and investigated.
Ring size effects in cyclic fluorophosphites: ligands that span the bonding space between phosphites and PF3
Authors: Miles-Hobbs Alexandra M. , Hunt Eliza , Pringle Paul. G. , Sparkes Hazel A.
Published: April 2019

From the evidence of the Mo(0), Pt(0) and Rh(i) complexes of cyclic fluorophosphites containing 5- to 8-membered rings, the binding properties depend critically on the ring size.
New anionic poly(alkylideneamine) dendrimers as microbicide agents against HIV-1 infection
Authors: Maciel Dina , Guerrero-Beltrán Carlos , Ceña-Diez Rafael , Tomás Helena , Muñoz-Fernández M. Ángeles , Rodrigues João
Published: April 2019

This type of dendrimers, specifically the low-generation G1, can directly interact with the viruses, hampering their entry in the cells, preventing the HIV-1 infection without the need of combined therapy.
Giant reduction of the random lasing threshold in CH3NH3PbBr3 perovskite thin films by using a patterned sapphire substrate
Authors: Weng Guoen , Tian Jiao , Chen Shiming , Xue Juanjuan , Yan Jiyu , Hu Xiaobo , Chen Shaoqiang , Zhu Ziqiang , Chu Junhao
Published: April 2019

Effective threshold reduction in a CH3NH3PbBr3 perovskite random laser due to multireflection processes at the perovskite/PSS interface.
Room-temperature superplasticity in Au nanowires and their atomistic mechanisms
Authors: Liu Pan , Wang Lihua , Yue Yonghai , Song Shuangxi , Wang Xiaodong , Reddy Kolan Madhav , Liao Xiaozhou , Zhang Ze , Chen Mingwei , Han Xiaodong
Published: April 2019

We report experimental observation of room-temperature superplasticity and the distinct nanosize effect on the deformation mechanisms of Au nanowires.
Synthesis, self-assembly and self-healing properties of organic–inorganic ABA triblock copolymers with poly(POSS acrylate) endblocks
Authors: Zhao Bingjie , Xu Sen , Zheng Sixun
Published: April 2019

A novel organic–inorganic ABA triblock copolymer with a poly(acrylate amide) (PAA) midblock and poly(POSS acrylate) [P(POSS)] endblocks was synthesized via sequential reversible addition–fragmentation chain transfer (RAFT) polymerization.
Spontaneous formation and reversible transformation between achiral J- and chiral H-aggregates of cyanine dye MTC
Authors: Guan Ai-Jiao , Zhang Jing-Tao , Wang Li-Xia , Cui Jie , Xiang Jun-Feng , Sun Xin , Chen Kuo , Li Qian , Tang Ya-Lin
Published: April 2019

Spontaneous transformation from achiral J-aggregates to chiral H-aggregates of cyanine dye MTC was investigated.
Biodegradable copolyester poly(butylene-co-isosorbide succinate) as hot-melt adhesives
Authors: Qu Dezhi , Sun Shuai , Gao Hongwei , Bai Yongping , Tang Ying
Published: April 2019

Biodegradable PBIS copolyesters can be used as hot-melt adhesives and tailored by varying the isosorbide content.
Correction: Cryogenic wormlike micelles
Authors: Yin Hongyao , Feng Yujun , Li Peixun , Doutch James , Han Yixiu , Mei Yongjun
Published: April 2019

Correction for ‘Cryogenic wormlike micelles’ by Hongyao Yin et al., Soft Matter, 2019, 15, 2511–2516.
ULA‐based near‐field source localisation in cognitive femtocell network: a comparative study of genetic algorithm hybridised with pattern search and swarm intelligence
Authors: Sultan Kiran , Alharbey R. A.
Published: April 2019

The rapidly proliferating wireless technology brings an overwhelming increase in wireless applications at a continuous pace. In this framework, a major proportion of overall voice and data traffic originates from indoor users, directing the research world towards the deployment of low‐power, low‐cost, and low‐range femtocell networks in the existing macrocells. However, this development will result in cross‐tier interference as well as interference to the primary or licensed users. Cognitive femtocell networks smartly address this challenge through their intelligent sensing and decision‐making capabilities. This study proposes a joint spectrum sensing technique, which involves individual sensing by multiple cognitive femtocell base stations (CFBSs), each equipped with a uniform linear array (ULA) of passive sensors. The local observations of CFBSs are then evaluated at the fusion centre to make final decision applying majority rule. In addition to the detection of a number of active primary femtocell networks (PFNs), the proposed near‐field source localisation technique provides four‐dimensional parameter estimation of each detected PFN signal, i.e. amplitude, angle‐of‐arrival, frequency, and range. Finally, the proposal is supported by three different implementations, i.e. Hybrid Genetic Algorithm, Particle Swarm Optimization, and Artificial Bee Colony. It also outsmarts an existing single‐ULA based spectrum sensing technique in the literature.
Rateless transmission of polar codes with information unequal error protection
Authors: Liang Hao , Liu Aijun , Zhang Ying Xian , Cheng Feng Yi
Published: April 2019

In this study, a rateless transmission scheme with information unequal error protection (UEP) is proposed by using polar codes. The proposed scheme is suitable for transmissions in time‐varying channels, as well as pursues UEP goal of information with different reliability requirements. Firstly, the authors design rateless transmission for an unknown channel via extending polarisation matrix and importance‐based puncturing. In particular, an algorithm ensuring full coding gain for UEP performance is proposed on the basis of rateless transmission. Moreover, in consideration of combining flexible successive cancellation list (SCL) decoding with UEP, they further present a size‐adapted SCL decoding scheme with reduced complexity. Numerical simulation shows that their proposed rateless scheme based on polar codes could achieve good UEP performance with low complexity in unknown channels.
Combinaisons de chimiothérapie ou de radiothérapie et d’inhibiteurs de checkpoints
Authors: Ghiringhelli François
Published: April 2019

Les progrès récents de l’immunothérapie en oncologie dus au développement des anticorps anti-PD1/PDL1 révolutionnent la prise en charge des patients. Malgré tout, l’efficacité de ces traitements en monothérapie est limitée à une sous-population représentant environ 25 à 30 % des patients dans la plupart des indications. Le développement de nouvelles stratégies se base sur les combinaisons entre les traitements standards (chimiothérapie cytotoxique et radiothérapie) et l’immunothérapie afin de trouver des combinaisons synergiques.
A Differentiated View on Short Stemmed Hip Arthroplasty – What are the Differences in Fixation and Biomechanics?
Authors: Jerosch Jörg , von Engelhardt Lars Victor
Published: April 2019

The present paper gives an overview of the different types of short stem total hip replacements. There is a pronounced inhomogeneity of the nomenclature in clinical practice as well as in regard to the scientific literature. Examples include neck preserving implants, meta-, epi- or metadiaphyseal fixed implants, microimplants, ultrashort implants, partial neck preserving implants, trochanteric sparing implants, implants with extra- and/or intramedullar fixation, implants without primary fixation, etc. Biomechanically, the short stems vary from very short, completely neck retaining versions up to implants which are just a shorter version of a standard implant. A frequently cited classification recommends the osteotomy level as a discriminating factor. This classification categorizes into a neck preserving, partial neck preserving and neck resecting short stems.
Thyroid hemiagenesis is combined with a variety of thyroid
disorders
Authors: Schneider Christina , Dietlein Markus , Faust Michael , Drzezga Alexander , Schmidt Matthias
Published: April 2019

Aim Thyroid hemiagenesis (TH) is a rare congenital anomaly in which one
thyroid lobe fails to develop. We describe our experience with at least 13
patients presenting with TH at our department.

Methods We retrospectively analysed patients with TH, who had been
referred primarily to our clinic between 2004 and 2010. In patients with TH,
thyroid function parameters and thyroid autoantibodies were examined.
99mTc-pertechnetate thyroid scintigraphy and sonography were
performed in all patients and confirmed the diagnosis of TH.

Results We identified 13 patients (11 women, 2 men) with TH in our patient
collective and calculated an estimated prevalence of TH of 0.08 %.

We found TH to occur more frequently in the left lobe and also more frequently in
females than in males. 9 patients presented with a total absence of one thyroid
lobe and 4 patients presented with severe hypoplasia of one thyroid lobe with an
isthmus appearing as a “hockey stick sign” on scintigraphic imaging. Associated
thyroid diseases could be observed in the remaining lobe in all patients and
included hyperthyroidism, hypothyroidism, nodular goiter, toxic goiter,
hypofunctioning nodules, Graves’ disease and Hashimoto-thyroiditis. The most
frequent thyroid disease in our patients with TH was nodular goiter. We did not
find any association of TH with malignancy.

Conclusion TH is mostly detected incidentally as the prevalence of TH is
extraordinary low. The fact that all of our patients with TH were also affected
by other forms of thyroid disease is reasonable since the patients were not
referred to the diagnostic centre due to TH but rather due to the associated
thyroid disease. Possibly there are different groups of TH: the symptomatic
hypothyroid children, the lifelong euthyroid adults who are diagnosed
incidentally through another thyroid disease and the patients with a molecular
failure of proper thyroid development.
Beginn der Insulintherapie bei Typ-2-Diabetes
Authors: Kress Stephan
Published: April 2019

Der erstmalige Beginn einer Insulintherapie beim Typ-2-Diabetes stellt für viele Patienten und Therapeuten eine Herausforderung dar. Die Notwendigkeit und der Beginn der Insulintherapie belasten den Patienten enorm und stellen oft einen schweren Einschnitt in seinem Leben dar. Dabei ist Typ-2-Diabetes nicht gleich Typ-2-Diabetes. Der Verlust der Betazellfunktion geschieht mit unterschiedlicher Geschwindigkeit. Und bereits zum Zeitpunkt der Diagnose kann die Betazellfunktion im Mittel um 50 % reduziert sein. Die Therapie sollte also vielmehr bedarfsgerecht auf mehrere Typen mit unterschiedlicher Betazellfunktion abgestimmt sein. Zahlreiche Studien demonstrieren, dass Patienten von einer frühen, sehr guten und stabilen Einstellung profitieren und vor einer Progression, d.h. dem weiteren Nachlassen der Betazellfunktion, geschützt werden. Darüber hinaus reduziert die frühe Therapieintensivierung nach Erstdiagnose eines Typ-2-Diabetes im Vergleich zum verzögerten Vorgehen das Risiko für kardiovaskuläre Erkrankungen bzw. Myokardinfarkte.
Update Hygiene: Prävention von Gefäßkatheter-assoziierten Infektionen bei Früh- und Neugeborenen
Authors: Eichel Vanessa , Papan Cihan , Mutters Nico T.
Published: April 2019

Hintergrund Die Kommission für Krankenhaushygiene und Infektionsprävention (KRINKO) des Robert Koch-Instituts hat im Mai 2018 eine Empfehlung mit wichtigen Neuerungen zum Thema Prävention von Gefäßkatheter-assoziierten Infektionen bei Früh- und Neugeborenen herausgegeben.

Ziel Zusammenfassende Darstellung, Erläuterung und kritische Diskussion der KRINKO Empfehlung.

Methoden Die Empfehlungen der KRINKO wurden zusammengefasst und unter Berücksichtigung der Originalquellen diskutiert.

Ergebnisse Insbesondere wurden Aussagen zur Anlage und Erhaltungspflege von Gefäßkathetern und zur Zubereitung von Infusionen formuliert. Insgesamt ist die Evidenz der Empfehlungen jedoch niedrig. Etwa 26% (19 von 74) sind unter Kategorie IA oder IB eingestuft. 40% der Empfehlungen entsprechen jedoch nur der Kategorie II, basieren also auf hinweisenden klinischen oder epidemiologischen Studien oder nachvollziehbaren theoretischen Begründungen. Entsprechend fehlt es an dringend gebrauchten klinischen Studien.

Diskussion Präventionsstrategien wurden detailliert besprochen und Fragestellungen aus der Praxis aufgegriffen. Die hohe Anzahl von Einzelempfehlungen mit teils niedrigem Evidenzgrad erfordern eine gemeinsame Beurteilung von Krankenhaushygienikern und Klinikern, um eine erfolgreiche Implementierung in der Praxis und eine Fokussierung auf die wichtigsten Inhalte, adaptiert an die Situation vor Ort, zu gewährleisten.
Ruthenium-Catalyzed Annulation of N-Cbz Hydrazones via C–H/N–N Bond Activation for the Rapid Synthesis of Isoquinolines
Authors: Deshmukh Dewal S. , Bhanage Bhalchandra M.
Published: April 2019

In this work, N-Cbz hydrazone has been employed as a rarely explored directing group for the synthesis of isoquinolines by annulation with internal alkynes via C–H/N–N activation using Ru catalyst. Additive as well as external oxidant-free rapid protocol has been established for the synthesis of isoquinolines using microwave strategy. Use of non-volatile and biodegradable PEG as a green solvent with lower catalyst loading makes the proposed protocol environmentally benign. Further, higher functional group tolerance and wide substrate scope has been observed under the stated methodology with higher yields.
Digitale hilfe für die erkrankte Psyche: Optimale Unterstützung bei psychischen Erkrankungen
Authors: Tergast Carsten
Published: April 2019

Die unterschiedlichen Berufsgruppen bei der Patientenversorgung optimal zu unterstützen, ist ein wesentliches Anliegen der Thieme Gruppe. Digitale Lösungen bieten die Möglichkeit, Versorgungslücken zu schließen und eine professionelle Nachversorgung zu gewährleisten. Hier setzt das Online-Coaching-Programm ProPerspektive.online von Thieme TeleCare an: Es begleitet Patienten mit Depression und Burn-out durch den Alltag.
New laser power sensor using diamagnetic levitation
Authors: Pinot P. , Silvestri Z.
Published: April 2019

This paper presents a preliminary study of an elementary device consisting of a small plate made from pyrolytic carbon levitated above a magnet array which is sensitive to any irradiating laser power. This device might provide an interesting alternative to power meters based on thermal measurement techniques via the Stefan-Boltzmann law or the photon-electron interaction. We show that the photo-response of a pyrolytic carbon plate in terms of levitation height versus irradiation power in the range of 20 mW to 1 W is sufficiently linear, sensitive, and reproducible to be used as a laser power sensor. The elevation height change as a function of irradiance time appears to be a suitable measurement parameter for establishing a relation with the irradiating laser power. The influence of some quantities affecting the measurement results has been highlighted. The study demonstrates that such a device should prove useful for applications in metrology, industry, or emerging technologies.
Metallic AsSb nanoinclusions strongly enriched by Sb in AlGaAsSb metamaterial
Authors: Bert Nikolay A. , Chaldyshev Vladimir V. , Cherkashin Nikolay A. , Nevedomskiy Vladimir N. , Preobrazhenskii Valery V. , Putyato Michael A. , Semyagin Boris R. , Ushanov Vitaliy I. , Yagovkina Maria A.
Published: April 2019

We have elucidated the microstructure of Al0.28Ga0.72As0.972Sb0.028 metamaterial containing a developed array of AsSb nanoinclusions. The AlGaAsSb films were grown by low-temperature molecular-beam epitaxy followed by high-temperature postgrowth thermal treatment. The process resulted in an array of self-organized AsSb nanoinclusions with an average diameter of 15 nm (after annealing at 750 °C), which occupied about 0.003 of the volume of the crystalline AlGaAsSb matrix. The nanoinclusions were found to have an A7-type rhombohedral microstructure and contained a very high concentration of antimony that exceeded 90%, whereas the Sb content in the AlGaAsSb matrix was 2.8 at. %. The strong enrichment of the inclusion with Sb resulted from the local thermodynamic equilibrium between the solid AlGaAsSb matrix and the As0.1Sb0.9 inclusions that became liquid at an annealing temperature of 750 °C. The inclusion-matrix orientation relationship was established to be (003)p || {111}m and [2¯110]p || 〈220〉m, similar to that for pure As precipitates in low-temperature grown GaAs despite a rather large difference in particle lattice constants and the c/a ratio. The increased inclusion-matrix lattice mismatch resulted in the generation of (001) prismatic dislocation loops associated with the inclusions bigger than 8.5 nm in diameter. The Burgers vector of the dislocation was determined as b = amatrix[001]. The established microstructural and compositional features create an opportunity to specify plasmonic resonance conditions in the low-temperature grown AlGaAsSb metamaterial.
Tantalum sound velocity under shock compression
Authors: Akin Minta C. , Nguyen Jeffrey H. , Beckwith Martha A. , Chau Ricky , Ambrose W. Patrick , Fat’yanov Oleg V. , Asimow Paul D. , Holmes Neil C.
Published: April 2019

We used several variations of the shock compression method to measure the longitudinal sound velocity of shocked tantalum over the pressure range 37–363 GPa with a typical uncertainty of 1.0%. These data are consistent with Ta remaining in the bcc phase along the principal Hugoniot from ambient pressure to ≈300 GPa, at which pressure melting occurs. These data also do not support the putative melting phenomena reported below 100 GPa in some static compression experiments.
A filter or oscillator by a simple density hump for an intense laser propagating in a preformed plasma channel
Authors: Zhang Lei , Tang Rong-An , Hong Xue-Ren , Gao Ji-Ming , Yin Li-Ru , Tian Jian-Min , Cheng Rui-Jin , Xue Ju-Kui
Published: April 2019

Considering the relativistic self-focusing, the ponderomotive self-channel, and the preformed channel focusing, the effect of a density hump on the laser propagation in a preformed plasma channel is studied. The evolution equation of the laser spot size is derived by using the source-dependent expansion technique. It is found that the laser behavior after the hump strongly depends on the hump position and width and is also related to the hump altitude. For the incident laser with a constant spot size, the laser after the hump may oscillate or not change, only depending on the hump width under a certain hump altitude. For the incident laser with oscillation, the laser oscillation can be enlarged, decreased, unchanged, according to the hump width, position, and altitude. So, the density hump can play the role like a filter, or like an oscillator, or be ineffective by adjusting its width, position, and altitude. These results are well confirmed by the final numerical simulations.
Role of ion thermal velocity in the formation and dynamics of electrostatic solitary waves in plasmas
Authors: Kakad Amar , Kakad Bharati , Lotekar Ajay , Lakhina G. S.
Published: April 2019

We perform fluid simulations to examine the effect of ion thermal velocity on the formation and dynamics of solitary waves in an unmagnetized two-component plasma consisting of ions and electrons. Based on the linear and nonlinear fluid theories, some of the previous studies have reported that the plasma with the electron temperature greater than the ion temperature (i.e., Te > Ti) supports ion acoustic solitary waves (IASWs), whereas the plasma with Te ≪ Ti supports electron acoustic waves (EASWs). In this paper, we have considered a wide range of ion temperatures (with fixed electron temperature) to examine the criteria of temperature and thermal velocities in the generation of EASWs and IASWs in plasmas. Our simulation shows that the plasma with Ti > Te possesses two wave modes depending on the ratio of its thermal velocities. When the ratio of electron to ion thermal velocities R = Vthe/Vthi > 1, the system supports the generation of IASWs, whereas for R < 1, it supports the generation of EASWs. The analysis of characteristics like the amplitude, width, and phase speed of these solitary waves implies that the EASWs have a negative potential, whereas the IASWs have the positive potential. The transition from IASWs to EASWs occurs when the phase speed of the solitary wave exceeds the limiting value of 3Vthe. This simulation study presents the detailed investigation of the evolution of EASWs and IASWs generated in plasmas having Ti > Te, which will have implications in modeling such waves in space and laboratory plasmas.
Application of viscoelasticity to nonlinear analyses of circular and spherical dielectric elastomers
Authors: Zhang Hui , Dai Min , Zhang Zhisheng
Published: April 2019

Time-dependent dissipative behaviors of circular and spherical dielectric elastomer (DE) membranes were investigated, and viscoelastic models based on nonlinear theory were developed. Using these formulas, one can easily understand the electromechanical performance of DEs. By combining the Maxwell stress, mechanical stress, energy principle, Gent model (for circular membranes), and neo-Hookean model (for balloon-shaped membranes), we derived governing equations that describe membrane deformation. The voltage versus stretch curves of VHB-based thin films was N-shaped, and the peak applied voltage decreased as the viscoelastic stretch grew. Membranes with smaller original radii required shorter relaxation times. When the viscoelastic relaxation time was very short, the viscoelasticity could be negligible. There were clear differences between the theoretical analyses of circular and spherical DE membranes. For example, the radial stretch was different and the ideal gas law was used for DE balloons but not for circular films. Our experiments indicated large deformations of both types of DE membranes at 5 kV. However, electromechanical instability can appear over time. According to our theoretical analysis, a DE membrane can reach equilibrium after viscoelastic relaxation. The presence of viscoelasticity lowered the response speeds but increased the mean stretch of DE films. These models are expected to provide guidance for DE device design and application.
Local-structure effects on 31P NMR chemical shift tensors in solid state
Authors: Chernyshov Ivan Yu. , Vener Mikhail V. , Shenderovich Ilya G.
Published: April 2019

The effect of the local structure on the 31P NMR chemical shift tensor (CST) has been studied experimentally and simulated theoretically using the density functional theory gauge-independent-atomic-orbital approach. It has been shown that the dominating impact comes from a small number of noncovalent interactions between the phosphorus-containing group under question and the atoms of adjacent molecules. These interactions can be unambiguously identified using the Bader analysis of the electronic density. A robust and computationally effective approach designed to attribute a given experimental 31P CST to a certain local morphology has been elaborated. This approach can be useful in studies of surfaces, complex molecular systems, and amorphous materials.
Noncontact evaluation of electrical passivation of oxidized silicon using laser terahertz emission microscope and corona charging
Authors: Mochizuki T. , Ito A. , Nakanishi H. , Tanahashi K. , Kawayama I. , Tonouchi M. , Shirasawa K. , Takato H.
Published: April 2019

We evaluated electrical passivation of crystalline silicon wafers possessing oxidized layers using a laser terahertz (THz) emission microscope, measuring waveforms of laser-excited THz emission from those surfaces with a corona charging setup to tune surface potential without electrical contact. The THz waveform strongly correlated to the surface potential, evaluated by measuring surface photovoltage using a Kelvin probe when the surface was depleted or inverted. The waveform also correlated to the potential of the surface in the accumulation mode and inverted near the flatband condition. The minority carrier lifetime agreed with the theoretically determined dependence on the charge density. These results indicate that the surface potential of a semiconductor covered by an insulator which can be charged by the corona charging setup can be evaluated by assessing the THz emission. Further, such a sample can also be used as a reference to quantitatively relate the waveform of the THz emission and the internal field of surface band bending in semiconductors.
Influences of out-of-plane elastic energy and thermal effects on friction between graphene layers
Authors: Dong Yun , Wang Fuqiang , Zhu Zongxiao , He Tianjing
Published: April 2019

Through molecular dynamic simulations, a system for investigating the contributions of elastic deformation energy and thermal activation effects to friction has been constructed. In this system, a graphene flake slides on a suspended graphene layer anchored on a bed of springs. The “graphene–spring” system provides a useful ideal approach to model different layers of graphene through changing the stiffness of the springs. The results first indicate that both the friction force and the elastic deformation energy have an exponential dependence on the support stiffness. Second, the observed non-monotonic variation in friction manifested by peaks and plateaus with increasing temperature results from the changing rate of energy dissipation due to the transition of slip regimes. Therefore, we suggest that the friction force emanates from the competition between the interfacial energy barrier and out-of-plane elastic deformation energy, as well as the competition between the thermal activation effects and transition of slip regimes. Therefore, the observation can extend the validity of the Prandtl–Tomlinson model on friction phenomena. Our simulations are intended to provide theoretical guidance when considering the influence of stiffness on the friction between graphene layers in the design of nanodevices.
Stability of iron selenide nanophases prepared by mechanosynthesis
Authors: Ulbrich K. F. , Campos C. E. M.
Published: April 2019

We have recently reported a method for obtaining about 30% of tetragonal β-FeSe in coexistence with hexagonal δ-FeSe and α-Fe phases by ball milling under an inert atmosphere, starting from FexSe powders with x = 1.00, 1.25 or 1.50, in which the use of Fe1.25Se or Fe1.50Se leads to more than 93% of β-FeSe after annealing at 400 °C for 1 h under vacuum [K. F. Ulbrich and C. E. M. Campos, RSC Adv. 8(15), 8190–8198 (2018)]. In this paper, we describe the phase stability of the samples and reveal a remarkable δ→β phase transition with storage time. The β-FeSe phase content increased exponentially during the first 30 days of storage, reaching about 70% in Fe1.5Se. X-ray powder diffraction and Rietveld analysis were used to evaluate changes in crystal structure and microstructure. Aging had only a mild effect on the magnetization curves of the samples, suggesting that the magnetism of mechanically alloyed iron selenide is governed mainly by the content of α-Fe.
Gyrokinetic continuum simulations of plasma turbulence in the Texas Helimak
Authors: Bernard T. N. , Shi E. L. , Gentle K. W. , Hakim A. , Hammett G. W. , Stoltzfus-Dueck T. , Taylor E. I.
Published: April 2019

The first gyrokinetic simulations of plasma turbulence in the Texas Helimak device, a simple magnetized torus, are presented. The device has features similar to the scrape-off layer region of tokamaks, such as bad-curvature-driven instabilities and sheath boundary conditions on the end plates, which are included in these simulations. Comparisons between simulations and measurements from the experiment show not only similarities, including equilibrium profiles and fluctuation amplitudes that approach experimental values, but also some important quantitative differences. Both experimental and simulation results exhibit turbulence statistics that are characteristic of blob transport.
Simulation of surface deformation control during selective laser melting of AlSi10Mg powder using an external magnetic field
Authors: Chen Liwei , Li Hui , Liu Sheng , Shen Shengnan , Zhang Tao , Huang Yicang , Zhang Guoqing , Zhang Yunfan , He Bo , Yang Chongkun
Published: April 2019

Selective laser melting (SLM) produces complex physical behaviors. After laser melting, the molten pool condenses with an uneven surface, which influences the next powder spreading process and affects the quality of the final product. This phenomenon is mainly caused by the Marangoni effect, which is generated by the surface tension of the liquid. This paper describes a method to control the surface deformation during the SLM of AlSi10Mg powder. It is assumed that there is a magnetic field (MF) added to the alloy powder generating a Lorentz force in the molten pool (MP). The Lorentz force can decrease the impact of the Marangoni effect and change the velocity field. Our work simulates the AlSi10Mg alloy melting process, and analyzes the physical parameters of the MP with or without an MF. It is found that increasing the MF within a certain range decreases the impact of the Marangoni effect, resulting in a smoother surface.
Motion of active tracer in a lattice gas with cross-shaped particles
Authors: Chatterjee Rakesh , Segall Nimrod , Merrigan Carl , Ramola Kabir , Chakraborty Bulbul , Shokef Yair
Published: April 2019

We analyze the dynamics of an active tracer particle embedded in a thermal lattice gas. All particles are subject to exclusion up to third nearest neighbors on the square lattice, which leads to slow dynamics at high densities. For the case with no rotational diffusion of the tracer, we derive an analytical expression for the resulting drift velocity v of the tracer in terms of non-equilibrium density correlations involving the tracer particle and its neighbors, which we verify using numerical simulations. We show that the properties of the passive system alone do not adequately describe even this simple system of a single non-rotating active tracer. For large activity and low density, we develop an approximation for v. For the case where the tracer undergoes rotational diffusion independent of its neighbors, we relate its diffusion coefficient to the thermal diffusion coefficient and v. Finally, we study dynamics where the rotation of the tracer is limited by the presence of neighboring particles. We find that the effect of this rotational locking may be quantitatively described in terms of a reduction in the rotation rate.
A method for reducing errors of magnetization modeling of nanocrystalline alloy cores based on modified Jiles-Atherton model
Authors: Zhang He , Liu Yi , Liu Siwei , Lin Fuchang
Published: April 2019

The Jiles-Atherton (J-A) model is widely used in the modeling of the magnetization process of magnetic cores, but its simulation accuracy in the nonlinear section of hysteresis loops is low due to its theoretical defect. To improve its simulation accuracy, a method for reducing simulation errors arising from the original J-A model is proposed, and thereby a modified J-A model is established. Measured hysteresis loops of nanocrystalline alloy cores at different frequencies are simulated using the original J-A model, and simulation errors are concentrated mainly in the nonlinear section of the hysteresis loops. Simulation results of the original J-A model are modified using the modified J-A model, and thereby the simulation errors in the nonlinear section are greatly reduced. This indicates that the modified J-A model can more accurately describe the magnetization process of cores.
Critical neuromorphic computing based on explosive synchronization
Authors: Choi Jaesung , Kim Pilwon
Published: April 2019

Synchronous oscillations in neuronal ensembles have been proposed to provide a neural basis for the information processes in the brain. In this work, we present a neuromorphic computing algorithm based on oscillator synchronization in a critical regime. The algorithm uses the high-dimensional transient dynamics perturbed by an input and translates it into proper output stream. One of the benefits of adopting coupled phase oscillators as neuromorphic elements is that the synchrony among oscillators can be finely tuned at a critical state. Especially near a critical state, the marginally synchronized oscillators operate with high efficiency and maintain better computing performances. We also show that explosive synchronization that is induced from specific neuronal connectivity produces more improved and stable outputs. This work provides a systematic way to encode computing in a large size coupled oscillator, which may be useful in designing neuromorphic devices.
Low-field formation of room-temperature biskyrmions in centrosymmetric MnPdGa magnet
Authors: Xiao Xiaofei , Peng Licong , Zhao Xinguo , Zhang Ying , Dai Yingying , Guo Jie , Tong Min , Li Ji , Li Bing , Liu Wei , Cai Jianwang , Shen Baogen , Zhang Zhidong
Published: April 2019

Magnetic skyrmions, a kind of localized spin texture topologically protected in magnetic materials, characterized by smaller size and much lower manipulating current density in comparison with ferromagnetic domain walls, are highlighted as potential information carriers for high-density magnetic storage devices. For technological applications, the stabilization of skyrmions in a temperature range around room temperature under a low magnetic field is essential. Here, we demonstrate the formation of magnetic biskyrmions in a low magnetic field at room temperature in a centrosymmetric hexagonal MnPdGa magnet via Lorentz transmission electron microscopy in combination with transport and magnetic measurements. High-density biskyrmions are generated at 300 K in a magnetic field of 0.15 T. In addition, biskyrmions can be generated from ferromagnetic domains and partly remained at zero field when the magnetic field is decreased. A large topological Hall resistivity is observed near room temperature. Furthermore, a wide temperature and magnetic-field window for biskyrmions is deduced from transport and magnetic properties. The simultaneous features of high-density and low magnetic field near room temperature in a single-component material make MnPdGa a promising candidate for future skyrmion-based topological spintronic applications.
High photoresponsivity in a GaAs film synthesized on glass using a pseudo-single-crystal Ge seed layer
Authors: Nishida T. , Moto K. , Saitoh N. , Yoshizawa N. , Suemasu T. , Toko K.
Published: April 2019

Research to synthesize a high-quality GaAs film on an inexpensive substrate has been continuing for decades in the quest to develop a solar cell that achieves both high efficiency and low-cost. Here, we applied a large-grained Ge layer on glass, formed by Al-induced layer exchange, to an epitaxial template for a GaAs film. The GaAs film, grown epitaxially from the Ge seed layer at 520 °C, became a pseudosingle crystal (grain size > 100 μm) with high (111) orientation. Reflecting the large grain size, the internal quantum efficiency reached 70% under a bias voltage of 1.0 V. This value approaches that of a simultaneously formed GaAs film on a single-crystal Ge wafer and is the highest for a GaAs film synthesized on glass at a low temperature. The application of a Ge seed layer formed by layer exchange offers excellent potential to develop high-efficiency thin-film solar cells with III–V compound semiconductors based on low-cost glass substrates.
Nature of the floppy-to-rigid transition in chalcogenide glass-forming liquids
Authors: Sen Sabyasachi , Xia Yiqing , Zhu Weidi , Lockhart Mark , Aitken Bruce
Published: April 2019

The viscoelastic properties of supercooled AsxSe100−x and GexSe100−x (0 ≤ x ≤ 30) liquids are studied using oscillatory parallel plate rheometry. The liquids with average selenium chain segment length L longer than ∼3 to 5 atoms or average coordination number ⟨r⟩ less than ∼2.2 are characterized by the coexistence of a low-frequency bond scission/renewal based relaxation process as well as high-frequency segmental chain dynamics. The latter process disappears for liquids with higher connectivity, thus implying a dynamical rigidity transition. The temporal decoupling of the high-frequency chain mode from that of the bond scission/renewal process and the shear modulus Gs associated with the low-frequency mode are shown to be unique functions of L or ⟨r⟩ and display strong similarity with the corresponding variation in the fragility m and the conformational entropy of the chain segments. When taken together, these results provide direct experimental support to the entropic rigidity argument originally proposed by Phillips but suggest a floppy-to-rigid transition of the structural network at ⟨r⟩ ∼ 2.2, instead of the conventional rigidity percolation threshold value of 2.4.
Highly efficient top-emission organic light-emitting diode on an oxidized aluminum anode
Authors: Lee Jae-Jin , Li Peicheng , Kung Hao-Ting , Lu Zheng-Hong
Published: April 2019

In today's manufacturing of organic light-emitting diode on silicon for microdisplay technologies, a top-emitting OLED (TEOLED) is required to be fabricated on top of an active-matrix circuitry located on the silicon backplane. This requires a highly reflective anode to enhance the luminance output. However, during the production process of a TEOLED, the hole injection efficiency and electrical conductivity may be suppressed by environmental exposure, in particular, moisture and oxygen. Given this, aluminum is an unfavorable reflective anode due to the primary concern of its native insulating oxide layer. The native oxide tends to grow during the patterning of the metal anode. In this paper, we have discovered that, by utilizing an Al2O3/MoO3 heterojunction anode structure, a highly efficient device can be made to achieve a current efficiency of 94 cd/A at a luminance of 1000 cd/m2. X-ray/ultraviolet photoelectron spectroscopy measurements show the formation of molybdenum gap states and favorable energy level alignment for hole injection.
Reduction of light shifts in Ramsey spectroscopy with a combined error signal
Authors: Shuker M. , Pollock J. W. , Boudot R. , Yudin V. I. , Taichenachev A. V. , Kitching J. , Donley E. A.
Published: April 2019

Light-induced frequency shifts can be a key limiting contribution to the mid- and long-term frequency instabilities in atomic clocks. In this letter, we demonstrate the experimental implementation of the combined error signal interrogation protocol to a cold-atom clock based on coherent population trapping (CPT) and Ramsey spectroscopy. The method uses a single error signal that results from the normalized combination of two error signals extracted from two Ramsey sequences of different dark periods. The single combined error signal is used to stabilize the atomic clock frequency. Compared to the standard Ramsey-CPT interrogation, this method reduces the clock frequency sensitivity to light-shift variations by more than one order of magnitude. This method can be applied in various kinds of Ramsey-based atomic clocks, sensors, and instruments.
Seed-germination ecology of glyphosate-resistant and glyphosate-susceptible biotypes of Echinochloa colona in Australia
Authors: Mutti Navneet Kaur , Mahajan Gulshan , Chauhan Bhagirath Singh
Published: April 2019

Echinochloa colona L. (Link) (awnless barnyard grass) is one of the top three most problematic weeds of summer crops in Australia. This weed has evolved resistance to glyphosate. A study was conducted to evaluate the effect of environmental factors on the germination and seedling emergence of a glyphosate-resistant (GR) and a glyphosate-susceptible (GS) biotype of E. colona. The two biotypes had similar germination and emergence responses to light and temperature conditions, water stress, solution pH, sorghum residue cover and seed burial depth. Light stimulated germination more than dark conditions, and seeds germinated at a wide range of alternating day/night temperatures, from 20°C/10°C to 35°C/25°C, whereas no seeds germinated at 15°C/5°C. These results suggest that E. colona can emerge in spring, summer and autumn in Queensland. The sodium chloride concentration required to inhibit 50% germination was greater for the GR biotype (209 mm) than the GS biotype (174 mm). Seed germination was not affected by pH in the range 4–10. Water stress reduced germination by 50% at an osmotic potential of –0.44 MPa. In a shade-house study, retention of sorghum residue cover on the soil surface reduced the seedling emergence of E. colona. Emergence was 70% in the absence of crop residue, whereas a residue amount of 8 t ha–1 reduced emergence to 47%. Emergence was greatest for seeds placed on the soil surface and declined linearly with increasing burial depth; no seedlings emerged from 8 cm depth. The GR biotype had higher germination than the GS biotype under high sodium chloride concentrations; therefore, this biotype may be highly competitive with crops under highly saline conditions. Because germination was high on the soil surface and was stimulated by light, this weed will remain problematic under no-till farming systems in Australia.
Sex determining region Y (SRY) sequencing and non-invasive molecular sexing in three wild species: brown (Parahyaena brunnea) and spotted (Crocuta crocuta) hyenas and aardvark (Orycteropus afer)
Authors: Vozdova Miluse , Kubickova Svatava , Rubes Jiri
Published: April 2019

Non-invasive molecular sexing methods are useful in captive breeding programs and field studies; these methods enable sex identification without immobilisation or stressful handling of animals. We developed a method enabling fast and reliable sex identification in three species with limited external sexual dimorphism: the brown and spotted hyenas and the aardvark. We used the sex determining region Y (SRY) gene as the male-specific sequence and the c-myc gene, highly conserved among mammals, as the control sequence present in both sexes. Primers designed on the basis of the feline and human SRY gene enabled us to amplify and sequence the SRY gene fragment in hyenas and the aardvark. Subsequently, we used specific primers designed on the basis of the newly obtained sequences for sex determination in two brown hyenas, three spotted hyenas and six aardvarks. The sequences of the SRY gene fragments were further studied. Interspecies comparisons revealed high similarity in SRY sequences between both hyena species, as well as their relationships with the Felidae lineage. The aardvark, as the only species of the order Tubulidentata (Afrotheria), showed SRY gene similarities with Sirenia and Primates. Knowledge of phylogenetic relationships can be beneficial in genetic studies focused on species with limited sequence data.
Conserved serum protein biomarkers associated with growing early colorectal adenomas
Authors: Ivancic Melanie M. , Anson Leigh W. , Pickhardt Perry J. , Megna Bryant , Pooler Bryan D. , Clipson Linda , Reichelderfer Mark , Sussman Michael R. , Dove William F.
Published: April 2019

Significance

The premalignant colonic adenoma presents a long-lived target to prevent colon cancer. The levels of peptide biomarkers for four serum proteins—F5, ITIH4, LRG1, and VTN—are each elevated in sera in two adenoma-bearing animal models and in patients. The elevated levels of these serum proteins are correlated with total colonic adenoma number in the rat model. Longitudinal analysis of patients demonstrated their association with the subset of adenomas that continue to grow, but not with the total volume of the adenoma burden. This pattern of correlation with the number and growth, but not total adenoma volume, indicates that this class of marker can complement an emergent class of volume-dependent markers to detect the growing early colonic adenoma, minimizing overdiagnosis.
Locus coeruleus toggles reciprocal prefrontal firing to reinstate fear
Authors: Giustino Thomas F. , Fitzgerald Paul J. , Ressler Reed L. , Maren Stephen
Published: April 2019

Significance

Fear relapse represents a significant problem for individuals suffering from stress- and trauma-related disorders such as posttraumatic stress disorder. Here, we show that locus coeruleus norepinephrine activation produces fear relapse in rats. In addition, locus coeruleus activation inverts neuronal firing properties of the prelimbic and infralimbic cortices to drive this fear relapse. Elevated noradrenergic tone and subsequent changes in prefrontal firing properties represent a therapeutic target for combating fear relapse.
Genome-wide effects on
Escherichia coli
transcription from ppGpp binding to its two sites on RNA polymerase
Authors: Sanchez-Vazquez Patricia , Dewey Colin N. , Kitten Nicole , Ross Wilma , Gourse Richard L.
Published: April 2019

The second messenger nucleotide ppGpp dramatically alters gene expression in bacteria to adjust cellular metabolism to nutrient availability. ppGpp binds to two sites on RNA polymerase (RNAP) in
Escherichia coli
, but it has also been reported to bind to many other proteins. To determine the role of the RNAP binding sites in the genome-wide effects of ppGpp on transcription, we used RNA-seq to analyze transcripts produced in response to elevated ppGpp levels in strains with/without the ppGpp binding sites on RNAP. We examined RNAs rapidly after ppGpp production without an accompanying nutrient starvation. This procedure enriched for direct effects of ppGpp on RNAP rather than for indirect effects on transcription resulting from starvation-induced changes in metabolism or on secondary events from the initial effects on RNAP. The transcriptional responses of all 757 genes identified after 5 minutes of ppGpp induction depended on ppGpp binding to RNAP. Most (>75%) were not reported in earlier studies. The regulated transcripts encode products involved not only in translation but also in many other cellular processes. In vitro transcription analysis of more than 100 promoters from the in vivo dataset identified a large collection of directly regulated promoters, unambiguously demonstrated that most effects of ppGpp on transcription in vivo were direct, and allowed comparison of DNA sequences from inhibited, activated, and unaffected promoter classes. Our analysis greatly expands our understanding of the breadth of the stringent response and suggests promoter sequence features that contribute to the specific effects of ppGpp.
Use of extracellular vesicles from lymphatic drainage as surrogate markers of melanoma progression and BRAF
V600E mutation
Authors: García-Silva Susana , Benito-Martín Alberto , Sánchez-Redondo Sara , Hernández-Barranco Alberto , Ximénez-Embún Pilar , Nogués Laura , Mazariegos Marina S. , Brinkmann Kay , Amor López Ana , Meyer Lisa , Rodríguez Carlos , García-Martín Carmen , Boskovic Jasminka , Letón Rocío , Montero Cristina , Robledo Mercedes , Santambrogio Laura , Sue Brady Mary , Szumera-Ciećkiewicz Anna , Kalinowska Iwona , Skog Johan , Noerholm Mikkel , Muñoz Javier , Ortiz-Romero Pablo L. , Ruano Yolanda , Rodríguez-Peralto José L. , Rutkowski Piotr , Peinado Héctor
Published: April 2019

Liquid biopsies from cancer patients have the potential to improve diagnosis and prognosis. The assessment of surrogate markers of tumor progression in circulating extracellular vesicles could be a powerful non-invasive approach in this setting. We have characterized extracellular vesicles purified from the lymphatic drainage also known as exudative seroma (ES) of stage III melanoma patients obtained after lymphadenectomy. Proteomic analysis showed that seroma-derived exosomes are enriched in proteins resembling melanoma progression. In addition, we found that the BRAFV600E mutation can be detected in ES-derived extracellular vesicles and its detection correlated with patients at risk of relapse.