bluuebunny/crossref_metadata_2025 huggingface dataset:
CRISPR/Cas9-mediated mosaic mutation of SRY gene induces hermaphroditism in rabbits
Authors: Song Yuning , Xu Yuanyuan , Liang Mingming , Zhang Yuxin , Chen Mao , Deng Jichao , Li Zhanjun
Published: February 2018

Hermaphroditism is a rare disorder that affects sexual development, resulting in individuals with both male and female sexual organs. Hermaphroditism is caused by anomalies in genes regulating sex determination, gonad development, or expression of hormones and their receptors during embryonic development during sexual differentiation. SRY is a sex-determination gene on the Y chromosome that is responsible for initiating male sex determination in mammals. In this study, we introduced CRISPR/Cas9-mediated mutations in the high-mobility-group (HMG) region of the rabbit SRY. As expected, SRY-mutant chimeric rabbits were diagnosed with hermaphroditism, characterized by possessing ovotestis, testis, ovary and uterus simultaneously. Histopathology analysis revealed that the testicular tissue was immature and lacked spermatogenic cells, while the ovarian portion appeared normal and displayed follicles at different stages. This is the first report of a rabbit hermaphroditism model generated by the CRISPR/Cas9 system. This novel rabbit model could advance our understanding of the pathogenesis of hermaphroditism, and identify novel therapies for human clinical treatment of hermaphroditism.
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE)
Authors: Fossati M. , Mendel J. T. , Boselli A. , Cuillandre J. C. , Vollmer B. , Boissier S. , Consolandi G. , Ferrarese L. , Gwyn S. , Amram P. , Boquien M. , Buat V. , Burgarella D. , Cortese L. , Côté P. , Côté S. , Durrell P. , Fumagalli M. , Gavazzi G. , Gomez-Lopez J. , Hensler G. , Koribalski B. , Longobardi A. , Peng E. W. , Roediger J. , Sun M. , Toloba E.
Published: February 2018

The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band Hα+ [NII] imaging survey carried out with MegaCam at the Canada-France-Hawaii Telescope. During pilot observations taken in the spring of 2016 we observed NGC 4330, an intermediate mass (M*≃ 109.8M⊙) edge-on star forming spiral currently falling into the core of the Virgo cluster. While previous Hαobservations showed a clumpy complex of ionised gas knots outside the galaxy disc, new deep observations revealed a low surface brightness ~10 kpc tail exhibiting a peculiar filamentary structure. The filaments are remarkably parallel to one another and clearly indicate the direction of motion of the galaxy in the Virgo potential. Motivated by the detection of these features which indicate ongoing gas stripping, we collected literature photometry in 15 bands from the far-UV to the far-IR and deep optical long-slit spectroscopy using the FORS2 instrument at the ESO Very Large Telescope. Using a newly developed Monte Carlo code that jointly fits spectroscopy and photometry, we reconstructed the star formation histories in apertures along the major axis of the galaxy. Our results have been validated against the output of CIGALE, a fitting code which has been previously used for similar studies. We found a clear outside-in gradient with radius of the time when the quenching event started: the outermost radii were stripped ~500 Myr ago, while the stripping reached the inner 5 kpc from the centre in the last 100 Myr. Regions at even smaller radii are currently still forming stars fueled by the presence of HI and H2gas. When compared to statistical studies of the quenching timescales in the local Universe we find that ram pressure stripping of the cold gas is an effective mechanism to reduce the transformation times for galaxies falling into massive clusters. Future systematic studies of all the active galaxies observed by VESTIGE in the Virgo cluster will extend these results to a robust statistical framework.
Alcohol-Initiated Dinitrile Cyclization in Basic Media: A Route Toward Pyrazino[1,2-a]indole-3-Amines
Authors: Voskressensky Leonid , Festa Alexey , Golantsov Nikita , Storozhenko Olga , Shumsky Alexey , Varlamov Alexey
Published: February 2018

A selective route to the formation of 1-alkoxypyrazino[1,2-a]indole-3-amines through alcohol-initiated dinitrile cyclization, starting from N-(cyanomethyl)indole-2-carbonitriles under basic conditions, was discovered. The resulting compounds were shown to be unstable in solution, and a three-component reaction of the dinitrile, alcohol, and aromatic aldehyde was used to overcome the problem.
Dihydroxylation of Olefins with Potassium Permanganate Catalyzed­ by Imidazolium Salt
Authors: Luo Zhi-Bin , Xie Ji-Min , Khan Imran , Valeru Anil , Xu Yin , Liu Bin , Sangepu Bhavanarushi
Published: February 2018

The development of an efficient and cost-effective cis-di­hydroxylation reaction of acrylate derivatives was achieved. The reaction proceeded in acetone with an imidazolium salt as catalyst to furnish the dihydroxylation of olefins at 0–5 °C using KMnO4 as the oxidant. This efficient and non-aqueous protocol was highly suitable for the large-scale preparation of cis-dihydroxylated compounds from the corresponding acrylate derivatives in high yields without overoxidation.
Free Radical Cyclization of N-Arylacrylamides: Mild and Facile
Synthesis of 3-Thiocyanato Oxindoles
Authors: Chen Fu-Xue , Karmaker Pran , Qiu Jiashen , Wu Di , Yin Hongquan
Published: February 2018

A novel and convenient oxidative radical cyclization of N-substituted N-arylacrylamides for the synthesis of 3-thiocyanated oxindoles has been developed by using AgSCN and K2S2O8 as the radical source. This process allows a consistent and convenient access to SCN-containing heterocycles bearing a broad range of functional groups in good to excellent yields (up to 91%). Moreover, the use of inexpensive and readily available starting materials, operational simplicity, and excellent functional group tolerance makes this protocol practically attractive.
Formal Synthesis of Kanamienamide
Authors: Ye Tao , Li Yang , Guo Yian , Xu Zhengshuang
Published: February 2018

A formal total synthesis of the anticancer natural product kanamienamide has been accomplished. This communication describes two approaches to the macrocyclic core of the natural product. The key features of the route include an eﬃcient macrolactamization, a Corey–Bakshi–Shibata asymmetric reduction, and a Stork–Zhao–Wittig olefination.
Remote C–H Functionalization via Selective Hydrogen Atom Transfer
Authors: Nagib David , Stateman Leah , Nakafuku Kohki
Published: February 2018

The selective functionalization of remote C–H bonds via intramolecular hydrogen atom transfer (HAT) is transformative for organic synthesis. This radical-mediated strategy provides access to novel reactivity that is complementary to closed-shell pathways. As modern methods for mild generation of radicals are continually developed, inherent selectivity paradigms of HAT mechanisms offer unparalleled opportunities for developing new strategies for C–H functionalization. This review outlines the history, recent advances, and mechanistic underpinnings of intramolecular HAT as a guide to addressing ongoing challenges in this arena.

1 Introduction

2 Nitrogen-Centered Radicals

2.1 sp3 N-Radical Initiation

2.2 sp2 N-Radical Initiation

3 Oxygen-Centered Radicals

3.1 Carbonyl Diradical Initiation

3.2 Alkoxy Radical Initiation

3.3 Non-alkoxy Radical Initiation

4 Carbon-Centered Radicals

4.1 sp2 C-Radical Initiation

4.2 sp3 C-Radical Initiation

5 Conclusion
Locking Dorsal Plate in Four-Bone Arthrodesis in SLAC and SNAC 3 Wrist
Authors: Querenghi Amos M. , Locatelli Francesco M. , Dacatra Ugo , Creta Elia , Tos Pierluigi , Odella Simona
Published: February 2018

Purpose The aim of this study was to evaluate the effectiveness and the safety of performing a four-bone arthrodesis (FBA) with dorsal locking plate in patients suffering from stage III scapholunate advanced collapse/scaphoid nonunion advance collapse (SLAC/SNAC) wrist.

Methods We evaluated retrospectively 20 patients surgically treated by a FBA with the use of locking dorsal plate. All the patients were clinically evaluated at follow-up for grip strength, range of motion, and pain (visual analog scale), and with the Disability of the Arm, Shoulder and Hand score and the Mayo wrist score. Imaging evaluation was performed on standard X-rays.

Results The mean follow-up was 6 years (range: 1–11 years). During follow-up, the patients showed good clinical outcomes in terms of pain relief and grip strength. Revision surgery was necessary only in one case because of screws loosening. In all cases, a solid bone fusion was achieved except in one patient, who presented a healing of lunocapitate joint. This condition did not affect the clinical outcomes.

Conclusion FBA performed using a dorsal locking plate is a salvage procedure effective in treating stage III SLAC/SNAC wrist. In our study, this technique provided good clinical outcomes at mid-term follow-up with a very low complication rate.

Level of Evidence Level IV, therapeutic case series.
Population Impact of Drug Interactions with Warfarin: A Real-World Data Approach
Authors: Martín-Pérez Mar , Gaist David , de Abajo Francisco , Rodríguez Luis
Published: February 2018

Objective To investigate the population impact of previously reported interactions between warfarin and other drugs on international normalized ratio (INR) levels.

Methods Using The Health Improvement Network (THIN), a United Kingdom primary care database, a cohort of warfarin users between 2005 and 2013 (N = 121,962) was followed until the first qualifying prescription for the potential interacting drugs was evaluated. Sixteen sub-cohorts, one for each study drug, and a control sub-cohort of warfarin were ascertained. Short-term changes in INR levels were assessed by comparing INR values measured before and after initiation of the interacting drug with paired Student's t-test. We also evaluated the proportion of patients with INR values outside the therapeutic range (INR: 2–3).

Results Miconazole use was associated with the highest mean increase in INR (+3.35), followed by amiodarone (+1.28), fluconazole (+0.79), metronidazole (+0.75) and nystatin (+0.65). After subtracting the natural INR variation observed in the control sub-cohort, supra-therapeutic levels (INR > 3) were found in 53.2% (miconazole), 45.5% (amiodarone), 23.3% (metronidazole), 23.2% (fluconazole) and 17.6% (nystatin) of patients initiating treatment with these drugs. Carbamazepine use was associated with a mean INR decrease of –0.63 and infra-therapeutic levels (INR < 2) were observed in 46.2% of patients initiating carbamazepine. For all other drugs, the change was small to moderate, in absolute INR units (+0.23 to +0.55) and in the proportion of patients with INR levels out of therapeutic range (<16%).

Conclusions Clinically potentially important interactions were observed in several study drugs. The majority of them, although confirmed, had little impact after adjusting for standard INR variability in the general population of warfarin users.
The Effect of Axial Loading on Ulnar Variance
Authors: Zhu Andy , Siljander Breana , Lawton Jeffrey , Waljee Jennifer , Ozer Kagan
Published: February 2018

Background Forearm rotation results in change in ulnar variance. Axial loading of the wrist is required to maintain daily activities. Change in ulnar variance during axial loading has not been investigated previously.

Purpose To measure the change in ulnar variance on axially loaded wrists.

Patients and Methods We examined 21 asymptomatic individuals and 24 patients with unilateral ulnar-sided wrist pain. All patients underwent standard neutral posteroanterior wrist radiographs without load and under axial loading on bilateral wrists. Axial loading was standardized at 18.1 kgf using an analog weight scale. A magnetic resonance (MR) arthrogram was obtained only in patients with ulnar-sided wrist pain. Beighton flexibility score was recorded on healthy volunteers. Change in ulnar variance between 0 and 18.1 kgf was compared for each wrist among all subjects. A correlation was sought between the change in ulnar variance, MR arthrogram findings, and physical examination.

Results In individuals without wrist pain, on average, 0.4 mm increase in ulnar variance was measured between 0 and 18.1 kgf. There was no difference between the dominant and nondominant side. No correlation was found with increasing age. In contrast, patients with ulnar-sided wrist pain displayed an average increase of 0.8 mm in ulnar variance. Compared with the contralateral wrist, more than 1 mm increase in ulnar variance was correlated with intra-articular pathologies including dorsoulnar ligament disruption, central triangular fibrocartilage complex (TFCC) perforation, and foveal detachment.

Conclusion Compared with contralateral side, more than 1 mm increase in ulnar variance is suggestive of longitudinal instability or TFCC pathology.

Level of Evidence Level II, diagnostic.
Synthesis and Molecular Docking Studies of (E)-4-(Substituted-benzylideneamino)-2H-Chromen-2-one Derivatives: Entry to New Carbonic Anhydrase Class Of Inhibitors
Authors: Fattah Tanzeela , Saeed Aamer , Channar Pervaiz , Larik Fayaz , Hassan Mubashir , Raza Hussain , Abbas Qamar , Seo Sung-Yum
Published: February 2018

The present article illustrated the synthesis and characterization of a novel series of (E)-4-(substituted-benzylideneamino)-2H-chromen-2-one derivatives 4a-4j in good to excellent yields. The target compounds were synthesized by refluxing 4-aminocoumarin with aromatic aldehydes in ethanol. The structural confirmation was achieved by spectroscopic techniques such as (1H, 13C-NMR and FT-IR) and elemental analysis. The synthesized compounds were evaluated for carbonic anhydrase II (CA-II) inhibition and free radical scavenging activity. All the compounds showed CA-II inhibition in the micro molar range. The compound 4c exhibited higher potential in the series with IC50=0.0928±0.00545 µM (standard Acetazolamide IC50=0.997±0.0586 µM). Pharmacological investigations showed that the synthesized compounds 4a-4j obey Lipinsk’s rule. Compound 4c elicited drug likeness and showed drug score value of 0.05. Molecular docking analysis showed that compound 4c interacts with Asn66 and Gln91 amino acid residues. Graphical Abstract.
Diagnosenkodierung in deutschen Arztpraxen aus klassifikatorischer Sicht: Eine retrospektive Studie mit Routinedaten
Authors: Carnarius Sebastian , Heuer Joachim , Stausberg Jürgen
Published: February 2018

Ziel der Studie Niedergelassene Haus- und Fachärzte behandeln ein breites Spektrum an Erkrankungen. Das Kodieren von Diagnosen erfolgt mittels der jahresaktuellen Version der Internationalen statistischen Klassifikation der Krankheiten und verwandter Gesundheitsprobleme, 10. Revision, German Modification (ICD-10-GM). Das Ziel dieser Studie war, die aktuelle Breite und Tiefe der Diagnosendokumentation in der vertragsärztlichen Versorgung zu beschreiben. Unter den gegebenen Rahmenbedingungen konnte diese in einer Nutzung unterschiedlichster aber vielfach nicht-terminaler ICD-10-GM-Kodes erwartet werden.

Methodik Der retrospektiven Studie lagen Abrechnungsdatensätze von 900 Praxen aus 13 Arztgruppen der KV-Regionen Brandenburg und Nordrhein aus dem Abrechnungszeitraum Oktober 2014 – September 2015 zu Grunde. Eingeschlossen wurden 22 287 583 Datensätze. Der normierte Gini-Koeffizient wurde als Maß zur Darstellung der Konzentration verwendet.

Ergebnisse Der Anteil terminaler ICD-10-GM-Kodes an der Gesamtheit der Datensätze lag bei 97,6 %. Hierbei verzeichneten die HNO-Ärzte den größten Anteil (99,6 %), den geringsten Anteil die Orthopäden und Kardiologen (jeweils 94,0 %). Die größte Breite an unterschiedlichen ICD-10-GM-Kodes zeigte sich bei den Hausärzten (71,1 % aller terminalen Kodes), die geringste Breite bei den Augenärzten (22,9 %). Die geringste Konzentration von ICD-10-GM-Kodes zeigte sich bei den Hausärzten (Gini-Koeffizient: 0,56), die größte Konzentration bei den Augenärzten (0,93).

Schlussfolgerung Die Fachärzte nutzten hauptsächlich ein umschriebenes Set an ICD-10-GM-Kodes. Hausärzte nutzten nicht nur eine sehr weite Palette von ICD-10-GM-Kodes sondern kodierten diese sehr häufig terminal. Dies spricht für eine hohe Kodierqualität.
The shape and dynamics of the generation of the splash forms in single-phase systems after drop hitting
Authors: Sochan Agata , Beczek Michał , Mazur Rafał , Ryżak Magdalena , Bieganowski Andrzej
Published: February 2018

The splash phenomenon is being increasingly explored with the use of modern measurement tools, including the high-speed cameras. Recording images at a rate of several thousand frames per second facilitates parameterization and description of the dynamics of splash phases. This paper describes the impact of a single drop of a liquid falling on the surface of the same liquid. Three single-phase liquid systems, i.e., water, petrol, and diesel fuel, were examined. The falling drops were characterized by different kinetic energy values depending on the height of the fall, which ranged from 0.1 to 7.0 m. Four forms, i.e., waves, crowns, semi-closed domes, and domes, were distinguished depending on the drop energy. The analysis of the recorded images facilitated determination of the static and dynamic parameters of each form, e.g., the maximum height of each splash form, the width of the splash form at its maximum height, and the rate of growth of the splash form. We, Re, Fr, and K numbers were determined for all analyzed liquid systems. On the basis of the obtained values of dimensionless numbers, the areas of occurrence of characteristic splash forms were separated.
Core radial electric field and transport in Wendelstein 7-X plasmas
Authors: Pablant N. A. , Langenberg A. , Alonso A. , Beidler C. D. , Bitter M. , Bozhenkov S. , Burhenn R. , Beurskens M. , Delgado-Aparicio L. , Dinklage A. , Fuchert G. , Gates D. , Geiger J. , Hill K. W. , Höfel U. , Hirsch M. , Knauer J. , Krämer-Flecken A. , Landreman M. , Lazerson S. , Maaßberg H. , Marchuk O. , Massidda S. , Neilson G. H. , Pasch E. , Satake S. , Svennson J. , Traverso P. , Turkin Y. , Valson P. , Velasco J. L. , Weir G. , Windisch T. , Wolf R. C. , Yokoyama M. , Zhang D. ,   W7-X Team
Published: February 2018

The results from the investigation of neoclassical core transport and the role of the radial electric field profile (Er) in the first operational phase of the Wendelstein 7-X (W7-X) stellarator are presented. In stellarator plasmas, the details of the Er profile are expected to have a strong effect on both the particle and heat fluxes. Investigation of the radial electric field is important in understanding neoclassical transport and in validation of neoclassical calculations. The radial electric field is closely related to the perpendicular plasma flow (u⊥) through the force balance equation. This allows the radial electric field to be inferred from measurements of the perpendicular flow velocity, which can be measured using the x-ray imaging crystal spectrometer and correlation reflectometry diagnostics. Large changes in the perpendicular rotation, on the order of Δu⊥∼ 5 km/s (ΔEr ∼ 12 kV/m), have been observed within a set of experiments where the heating power was stepped down from 2 MW to 0.6 MW. These experiments are examined in detail to explore the relationship between heating power temperature, and density profiles and the radial electric field. Finally, the inferred Er profiles are compared to initial neoclassical calculations based on measured plasma profiles. The results from several neoclassical codes, sfincs, fortec-3d, and dkes, are compared both with each other and the measurements. These comparisons show good agreement, giving confidence in the applicability of the neoclassical calculations to the W7-X configuration.
Three-body dissociation of OCS3+: Separating sequential and concerted pathways
Authors: Kumar Herendra , Bhatt Pragya , Safvan C. P. , Rajput Jyoti
Published: February 2018

Events from the sequential and concerted modes of the fragmentation of OCS3+ that result in coincident detection of fragments C+, O+, and S+ have been separated using a newly proposed representation. An ion beam of 1.8 MeV Xe9+ is used to make the triply charged molecular ion, with the fragments being detected by a recoil ion momentum spectrometer. By separating events belonging exclusively to the sequential mode of breakup, the electronic states of the intermediate molecular ion (CO2+ or CS2+) involved are determined, and from the kinetic energy release spectra, it is shown that the low lying excited states of the parent OCS3+ are responsible for this mechanism. An estimate of branching ratios of events coming from sequential versus concerted mode is presented.
The performance and limitations of FPGA-based digital servos for atomic, molecular, and optical physics experiments
Authors: Yu Shi Jing , Fajeau Emma , Liu Lin Qiao , Jones David J. , Madison Kirk W.
Published: February 2018

In this work, we address the advantages, limitations, and technical subtleties of employing field programmable gate array (FPGA)-based digital servos for high-bandwidth feedback control of lasers in atomic, molecular, and optical physics experiments. Specifically, we provide the results of benchmark performance tests in experimental setups including noise, bandwidth, and dynamic range for two digital servos built with low and mid-range priced FPGA development platforms. The digital servo results are compared to results obtained from a commercially available state-of-the-art analog servo using the same plant for control (intensity stabilization). The digital servos have feedback bandwidths of 2.5 MHz, limited by the total signal latency, and we demonstrate improvements beyond the transfer function offered by the analog servo including a three-pole filter and a two-pole filter with phase compensation to suppress resonances. We also discuss limitations of our FPGA-servo implementation and general considerations when designing and using digital servos.
Study of magneto-electric coupling between ultra-thin Fe films and PMN-PT using X-ray magnetic circular dichroism
Authors: Avula S. R. V. , Heidler J. , Dreiser J. , Vijayakumar J. , Howald L. , Nolting F. , Piamonteze C.
Published: February 2018

X-ray absorption spectra and magnetic circular dichroism were measured at the Fe L3, 2-edges of an iron wedge deposited on a ferroelectric substrate in the total electron yield mode. Upon switching the ferroelectric polarization from Pup to Pdown, we observe a relative change in the total magnetic moment of 20% for 1.5 nm thin Fe. For 3 nm thin Fe, the relative change is within the sum rule error bar. Taking the sampling depth of the measurement method into account, this difference is compatible with a magnetic anisotropy change taking place in the first interfacial layer in contact with the ferroelectric substrate. We attribute this interfacial coupling to a charge accumulation or depletion at the interface.
Energy management and control system of DC-DC converter with super-capacitor and battery for recovering of train kinetic energy
Authors: Fallah M. , Asadi M. , Moghbeli H. , Dehnavi Gh. R.
Published: February 2018

One of the most important issues in power systems is the energy. Due to the fossil fuel downfall, global warming and greenhouse effect which are important environmental effects of fossil fuel burning to produce energy and energy price variation, energy saving, and recycling in industry especially in electrical vehicles and electrical trains are very important and vital. In this paper, the main aim is using a battery and a supercapacitor for train kinetic energy recovery in the braking mode and grid demand reduction in the acceleration mode. In this regard, a new DC-DC converter is proposed. An algorithm control that manages energy flow between the battery and super-capaciror (SC) in the proposed converter is designed. The control method is based on the sliding mode. Because of immeasurable internal and initial voltage of the supercapacitor, an observer extracts the internal voltage of the supercapacitor. In addition, acceleration and braking conditions of electrical trains and energy storage systems are simulated in MATLAB Simulink, and effectiveness of the proposed converter, energy management algorithm, and control system in different phases has been proven.
Molecular dynamics study of structure and vibrational spectra at zwitterionoic lipid/aqueous KCl, NaCl, and CaCl2 solution interfaces
Authors: Ishiyama Tatsuya , Shirai Shinnosuke , Okumura Tomoaki , Morita Akihiro
Published: February 2018

Molecular dynamics (MD) simulations of KCl, NaCl, and CaCl2 solution/dipalmytoylphosphatidylcholine lipid interfaces were performed to analyze heterodyne-detected vibrational sum frequency generation (HD-VSFG) spectra in relation to the interfacial water structure. The present MD simulation well reproduces the experimental spectra and elucidates a specific cation effect on the interfacial structure. The K+, Na+, and Ca2+ cation species penetrate in the lipid layer more than the anions in this order, due to the electrostatic interaction with negative polar groups of lipid, and the electric double layer between the cations and anions cancels the intrinsic orientation of water at the water/lipid interface. These mechanisms explain the HD-VSFG spectrum of the water/lipid interface and its spectral perturbation by adding the ions. The lipid monolayer reverses the order of surface preference of the cations at the solution/lipid interface from that at the solution/air interface.
Thermal diffusivity measurement in thin metallic filaments using the mirage method with multiple probe beams and a digital camera
Authors: Vargas E. , Cifuentes A. , Alvarado S. , Cabrera H. , Delgado O. , Calderón A. , Marín E.
Published: February 2018

Photothermal beam deflection is a well-established technique for measuring thermal diffusivity. In this technique, a pump laser beam generates temperature variations on the surface of the sample to be studied. These variations transfer heat to the surrounding medium, which may be air or any other fluid. The medium in turn experiences a change in the refractive index, which will be proportional to the temperature field on the sample surface when the distance to this surface is small. A probe laser beam will suffer a deflection due to the refractive index periodical changes, which is usually monitored by means of a quadrant photodetector or a similar device aided by lock-in amplification. A linear relationship that arises in this technique is that given by the phase lag of the thermal wave as a function of the distance to a punctual heat source when unidimensional heat diffusion can be guaranteed. This relationship is useful in the calculation of the sample’s thermal diffusivity, which can be obtained straightforwardly by the so-called slope method, if the pump beam modulation frequency is well-known. The measurement procedure requires the experimenter to displace the probe beam at a given distance from the heat source, measure the phase lag at that offset, and repeat this for as many points as desired. This process can be quite lengthy in dependence of the number points. In this paper, we propose a detection scheme, which overcomes this limitation and simplifies the experimental setup using a digital camera that substitutes all detection hardware utilizing motion detection techniques and software digital signal lock-in post-processing. In this work, the method is demonstrated using thin metallic filaments as samples.
Influence of pre-annealing of printed silver electrodes on ultrafast laser ablation of short thin-film transistor channels on flexible substrates
Authors: Wiig M. S. , You C. C. , Brox-Nilsen C. , Foss S. E.
Published: February 2018

The cutoff frequency and current from an organic thin-film transistor (OTFT) are strongly dependent on the length and to some extent on the uniformity of the transistor channel. Reducing the channel length can improve the OTFT performance with the increase in the current and frequency. Picosecond laser ablation of the printed Ag electrodes, compatible with roll-to-roll fabrication, has been investigated. The ablation threshold was found to be similar for the laser wavelengths tested: 515 nm and 1030 nm. Short transistor channels could be opened both after light annealing at 70 °C and after annealing at 140 °C. The channels in the lightly cured films had a significantly less scale formation, which is critical for avoiding shunts in the device. By moving from bottom electrodes fully defined by printing to the bottom electrodes where the transistor channel is opened by the laser, the channel length could be reduced from 40 μm to less than 5 μm.
A comparison of choline:urea and choline:oxalic acid deep eutectic solvents at 338 K
Authors: Gilmore Mark , Moura Leila M. , Turner Adam H. , Swadźba-Kwaśny Małgorzata , Callear Samantha K. , McCune Jade A. , Scherman Oren A. , Holbrey John D.
Published: February 2018

1:2 choline chloride:urea and 1:1 choline chloride:oxalic acid deep eutectic solvents are compared at 338 K using liquid-phase neutron diffraction with H/D isotopic substitution to obtain differential neutron scattering cross sections and fitting of models to the experimental data using Empirical Potential Structure Refinement. In comparison to the previously reported study of choline chloride:urea at 303 K, we observed significant weakening and lengthening of choline–OH⋯Cl− and choline–OH⋯hydrogen-bond acceptor correlations.
Nanoscale hydrodynamics near solids
Authors: Camargo Diego , de la Torre J. A. , Duque-Zumajo D. , Español Pep , Delgado-Buscalioni Rafael , Chejne Farid
Published: February 2018

Density Functional Theory (DFT) is a successful and well-established theory for the study of the structure of simple and complex fluids at equilibrium. The theory has been generalized to dynamical situations when the underlying dynamics is diffusive as in, for example, colloidal systems. However, there is no such a clear foundation for Dynamic DFT (DDFT) for the case of simple fluids in contact with solid walls. In this work, we derive DDFT for simple fluids by including not only the mass density field but also the momentum density field of the fluid. The standard projection operator method based on the Kawasaki-Gunton operator is used for deriving the equations for the average value of these fields. The solid is described as featureless under the assumption that all the internal degrees of freedom of the solid relax much faster than those of the fluid (solid elasticity is irrelevant). The fluid moves according to a set of non-local hydrodynamic equations that include explicitly the forces due to the solid. These forces are of two types, reversible forces emerging from the free energy density functional, and accounting for impenetrability of the solid, and irreversible forces that involve the velocity of both the fluid and the solid. These forces are localized in the vicinity of the solid surface. The resulting hydrodynamic equations should allow one to study dynamical regimes of simple fluids in contact with solid objects in isothermal situations.
Divacancy-tin related defects in irradiated germanium
Authors: Khirunenko L. I. , Sosnin M. G. , Duvanskii A. V. , Abrosimov N. V. , Riemann H.
Published: February 2018

A new absorption spectrum has been detected in the region of 770–805 cm−1 following the annealing of low temperature irradiated Sn-doped Ge. The spectrum develops simultaneously with the disappearance of the V2-related absorption band. The new spectra arise both in p- (doping with gallium) and n- (doping with antimony) type samples and are completely identical to the absorption spectrum of the corresponding dopants. The studies have shown that the defects responsible for the registered spectra have hydrogen-like excited states similar to those observed for hydrogen-like group-III acceptors and group-V donors in Ge. The defects are identified as SnV2Ga and SnV2Sb. The formation of the revealed complexes consists of two stages. During the first stage, the defects are created as a result of the direct interaction of SnV2 diffusing upon the annealing with atoms Ga or Sb. The second stage arises, apparently, due to the participation of SnV2 in the formation of intermediate defects that are optically inactive and transform into the revealed defects at annealing temperatures Tann. > 243 K.
Resonance fluorescence revival in a voltage-controlled semiconductor quantum dot
Authors: Reigue Antoine , Lemaître Aristide , Gomez Carbonell Carmen , Ulysse Christian , Merghem Kamel , Guilet Stéphane , Hostein Richard , Voliotis Valia
Published: February 2018

We demonstrate systematic resonance fluorescence recovery with near-unity emission efficiency in single quantum dots embedded in a charge-tunable device in a wave-guiding geometry. The quantum dot charge state is controlled by a gate voltage, through carrier tunneling from a close-lying Fermi sea, stabilizing the resonantly photocreated electron-hole pair. The electric field cancels out the charging/discharging mechanisms from nearby traps toward the quantum dots, responsible for the usually observed inhibition of the resonant fluorescence. Fourier transform spectroscopy as a function of the applied voltage shows a strong increase in the coherence time though not reaching the radiative limit. These charge controlled quantum dots can act as quasi-perfect deterministic single-photon emitters, with one laser pulse converted into one emitted single photon.
Optical AND operation in n-AlGaAs/GaAs heterojunction field effect transistor
Authors: Kawazu T. , Noda T. , Sakuma Y.
Published: February 2018

The near-infrared photoresponses of an n-AlGaAs/GaAs heterojunction field-effect transistor (FET) were investigated for the irradiation of two lights: (A) a laser beam with the energy above the Schottky-barrier which uniformly illuminates the gate region and (B) a laser beam with the energy above the GaAs bandgap which locally illuminates the ungate region. We measured a lateral photocurrent in the two dimensional electron gas (2DEG) channel at the n-AlGaAs/GaAs heterojunction and found that the FET acts as an optical AND element; the lateral photocurrent is generated only when both the light A and B simultaneously illuminate the FET. The lateral current flows from left to right when the left side of the FET is illuminated with the light B, while the right side irradiation leads to the current from right to left. The experimental findings are well explained by a theory based on the current-continuity equation, where the lateral current in the 2DEG channel is driven by an asymmetric electron transfer resulting from the simultaneous irradiation of the light A and B.
DFT study of structural and electronic properties of MoS2(1−x)Se2x alloy (x = 0.25)
Authors: Gusakova Julia , Gusakov Vasilii , Tay Beng Kang
Published: February 2018

First-principles calculations have been performed to study the structural features of the monolayer MoS2(1-x)Se2x (x = 0.25) alloy and its electronic properties. We studied the effects of the relative positions of Se atoms in a real monolayer alloy. It was demonstrated that the distribution of the Se atoms between the top and bottom chalcogen planes was most energetically favorable. For a more probable distribution of Se atoms, a MoS2(1-x)Se2x (x = 0.25) monolayer alloy is a direct semiconductor with a fundamental band gap equal to 2.35 eV (calculated with the GVJ-2e method). We also evaluated the optical band gap of the alloy at 77 K (1.86 eV) and at room temperature (1.80 eV), which was in good agreement with the experimentally measured band gap of 1.79 eV.
Radial confinement of deeply trapped particles in a non-symmetric magnetohydrodynamic equilibrium
Authors: Sengupta Wrick , Weitzner Harold
Published: February 2018

Quasisymmetry and omnigeneity of an equilibrium magnetic field are two distinct properties proposed to ensure radial localization of collisionless trapped particles in any stellarator. These constraints are incompletely explored, but have stringent restrictions on a magnetic geometry. This work employs an analytical approach to understand the implications of the constraints. The particles move in an intrinsically three dimensional equilibrium whose representation is given by the earlier work of Weitzner and its extension here. For deeply trapped particles, a local equilibrium expansion around a minimum of the magnetic field strength along a magnetic line suffices. This analytical non-symmetric equilibrium solution enables explicit representation of the constraints. The results show that it is far easier to satisfy the omnigeneity condition than the quasisymmetry requirement. Correspondingly, there exists a large class of equilibrium close to quasisymmetry that remains omnigeneous while allowing inclusion of error fields, which may destroy quasisymmetry.
Drop splashing is independent of substrate wetting
Authors: Latka Andrzej , Boelens Arnout M. P. , Nagel Sidney R. , de Pablo Juan J.
Published: February 2018

A liquid drop impacting a dry solid surface with sufficient kinetic energy will splash, breaking apart into numerous secondary droplets. This phenomenon shows many similarities to forced wetting, including the entrainment of air at the contact line. Because of these similarities and the fact that forced wetting has been shown to depend on the wetting properties of the surface, existing theories predict splashing to depend on wetting properties as well. However, using high-speed interference imaging, we observe that at high capillary numbers wetting properties have no effect on splashing for various liquid-surface combinations. Additionally, by fully resolving the Navier-Stokes equations at length and time scales inaccessible to experiments, we find that the shape and motion of the air-liquid interface at the contact line/edge of the droplet are independent of wettability. We use these findings to evaluate existing theories and to compare splashing with forced wetting.
Characterization of aluminum nitride based films with high resolution X-ray fluorescence spectroscopy
Authors: Anagnostopoulos D. F. , Siozios A. , Patsalas P.
Published: February 2018

X-ray fluorescence spectra of Al based films are measured, using a lab-scale wavelength dispersive flat crystal spectrometer. Various structures of AlN films were studied, like single layered, capped, stratified, nanostructured, crystalline, or amorphous. By optimizing the set-up for enhanced energy resolution and detection efficiency, the measured line shapes of Κα, Kβ, and KLL radiative Auger transitions are shown to be adequately detailed to allow chemical characterization. The chemistry identification is based on the pattern comparison of the emitted line shape from the chemically unknown film and the reference line shapes from standard materials, recorded under identical experimental conditions. The ultimate strength of lab-scale high resolution X-ray fluorescence spectroscopy on film analysis is verified, in cases that ordinary applied techniques like X-ray photoelectron and X-ray diffraction fail, while the characterization refers to the non-destructive determination of the bulk properties of the film and not to its surface, as the probed depth is in the micrometer range.
Effect of thermal insulation on the electrical characteristics of NbOx threshold switches
Authors: Wang Ziwen , Kumar Suhas , Wong H.-S. Philip , Nishi Yoshio
Published: February 2018

Threshold switches based on niobium oxide (NbOx) are promising candidates as bidirectional selector devices in crossbar memory arrays and building blocks for neuromorphic computing. Here, it is experimentally demonstrated that the electrical characteristics of NbOx threshold switches can be tuned by engineering the thermal insulation. Increasing the thermal insulation by ∼10× is shown to produce ∼7× reduction in threshold current and ∼45% reduction in threshold voltage. The reduced threshold voltage leads to ∼5× reduction in half-selection leakage, which highlights the effectiveness of reducing half-selection leakage of NbOx selectors by engineering the thermal insulation. A thermal feedback model based on Poole-Frenkel conduction in NbOx can explain the experimental results very well, which also serves as a piece of strong evidence supporting the validity of the Poole-Frenkel based mechanism in NbOx threshold switches.
Magnetostrictive clad steel plates for high-performance vibration energy harvesting
Authors: Yang Zhenjun , Nakajima Kenya , Onodera Ryuichi , Tayama Tsuyoki , Chiba Daiki , Narita Fumio
Published: February 2018

Energy harvesting technology is becoming increasingly important with the appearance of the Internet of things. In this study, a magnetostrictive clad steel plate for harvesting vibration energy was proposed. It comprises a cold-rolled FeCo alloy and cold-rolled steel joined together by thermal diffusion bonding. The performances of the magnetostrictive FeCo clad steel plate and conventional FeCo plate cantilevers were compared under bending vibration; the results indicated that the clad steel plate construct exhibits high voltage and power output compared to a single-plate construct. Finite element analysis of the cantilevers under bending provided insights into the magnetic features of a clad steel plate, which is crucial for its high performance. For comparison, the experimental results of a commercial piezoelectric bimorph cantilever were also reported. In addition, the cold-rolled FeCo and Ni alloys were joined by thermal diffusion bonding, which exhibited outstanding energy harvesting performance. The larger the plate volume, the more the energy generated. The results of this study indicated not only a promising application for the magnetostrictive FeCo clad steel plate as an efficient energy harvester, related to small vibrations, but also the notable feasibility for the formation of integrated units to support high-power trains, automobiles, and electric vehicles.
Fabrication of thin films of two-dimensional triangular antiferromagnet Ag2CrO2 and their transport properties
Authors: Taniguchi Hiroki , Suzuki Shota , Arakawa Tomonori , Yoshida Hiroyuki , Niimi Yasuhiro , Kobayashi Kensuke
Published: February 2018

We fabricated 100 nm thick films of two-dimensional triangular antiferromagnet Ag2CrO2 using the mechanical exfoliation technique, and performed the transport measurements down to 5 K. As in the case of polycrystalline samples, a large reduction of the resistivity due to the antiferromagnetic ordering was clearly observed at around 25 K. Surprisingly, the resistivity for the thin films is one order magnitude smaller than that for the polycrystalline samples, indicating that the crystalline nature is much better in the former than in the latter. The present result sheds new light on the use of atomic-layer antiferromagnetic materials for device applications.
Product interactions and feedback in diffusion-controlled reactions
Authors: Roa Rafael , Siegl Toni , Kim Won Kyu , Dzubiella Joachim
Published: February 2018

Steric or attractive interactions among reactants or between reactants and inert crowders can substantially influence the total rate of a diffusion-influenced reaction in the liquid phase. However, the role of the product species, which has typically different physical properties than the reactant species, has been disregarded so far. Here we study the effects of reactant–product and product–product interactions as well as asymmetric diffusion properties on the rate of diffusion-controlled reactions in the classical Smoluchowski-setup for chemical transformations at a perfect catalytic sphere. For this, we solve the diffusion equation with appropriate boundary conditions coupled by a mean-field approach on the second virial level to account for the particle interactions. We find that all particle spatial distributions and the total rate can change significantly, depending on the diffusion and interaction properties of the accumulated products. Complex competing and self-regulating (homeostatic) or self-amplifying effects are observed for the system, leading to both decrease and increase in the rates, as the presence of interacting products feeds back to the reactant flux and thus the rate with which the products are generated.
Micropillars with a controlled number of site-controlled quantum dots
Authors: Kaganskiy Arsenty , Gericke Fabian , Heuser Tobias , Heindel Tobias , Porte Xavier , Reitzenstein Stephan
Published: February 2018

We report on the realization of micropillars with site-controlled quantum dots (SCQDs) in the active layer. The SCQDs are grown via the buried stressor approach which allows for the positioned growth and device integration of a controllable number of QDs with high optical quality. This concept is very powerful as the number and the position of SCQDs in the cavity can be simultaneously controlled by the design of the buried-stressor. The fabricated micropillars exhibit a high degree of position control for the QDs above the buried stressor and Q-factors of up to 12 000 at an emission wavelength of around 930 nm. We experimentally analyze and numerically model the cavity Q-factor, the mode volume, the Purcell factor, and the photon-extraction efficiency as a function of the aperture diameter of the buried stressor. Exploiting these SCQD micropillars, we experimentally observe a Purcell enhancement in the single-QD regime with FP = 4.3 ± 0.3.
Multilayered current-induced domain wall motion in Pt/Tb-Co/Ta/Tb-Co/Pt magnetic wire
Authors: Kurokawa Yuichiro , Awano Hiroyuki
Published: February 2018

We fabricated a Pt (3 nm)/Tb0.28Co0.72 (4 nm)/Ta (4 nm)/Tb0.26Co0.74 (4 nm)/Pt (3 nm) multilayered magnetic wire and investigated current-induced domain wall motion within it. We found that the Hall resistance of the Pt/Tb-Co/Ta/Tb-Co/Pt wire has four stable levels under a magnetic field of zero. Moreover, we observed that the domain walls in both the upper and lower ferromagnetic layers are controlled by a single current source. This indicates that Pt/Tb-Co/Ta/Tb-Co/Pt wire can be used in multi-level magnetic wire memory.
The ecology of flows and drift wave turbulence in CSDX: A model
Authors: Hajjar R. J. , Diamond P. H. , Tynan G. R.
Published: February 2018

This paper describes the ecology of drift wave turbulence and mean flows in the coupled drift-ion acoustic wave plasma of a CSDX linear device. A 1D reduced model that studies the spatiotemporal evolution of plasma mean density n¯, and mean flows v¯y and v¯z, in addition to fluctuation intensity ε, is presented. Here, ε=〈ñ2+(∇⊥ϕ̃)2+ṽz2〉 is the conserved energy field. The model uses a mixing length lmix inversely proportional to both axial and azimuthal flow shear. This form of lmix closes the loop on total energy. The model self-consistently describes variations in plasma profiles, including mean flows and turbulent stresses. It investigates the energy exchange between the fluctuation intensity and mean profiles via particle flux 〈ñṽx〉 and Reynolds stresses 〈ṽxṽy〉 and 〈ṽxṽz〉. Acoustic coupling breaks parallel symmetry and generates a parallel residual stress Πxzres. The model uses a set of equations to explain the acceleration of v¯y and v¯z via Πxyres∝∇n¯ and Πxyres∝∇n¯. Flow dynamics in the parallel direction are related to those in the perpendicular direction through an empirical coupling constant σVT. This constant measures the degree of symmetry breaking in the 〈kmkz〉 correlator and determines the efficiency of ∇n¯ in driving v¯z. The model also establishes a relation between ∇v¯y and ∇v¯z, via the ratio of the stresses Πxyres and Πxzres. When parallel to perpendicular flow coupling is weak, axial Reynolds power PxzRe=−〈ṽxṽz〉∇v¯z is less than the azimuthal Reynolds power PxyRe=−〈ṽxṽy〉∇v¯y. The model is then reduced to a 2-field predator/prey model where v¯z is parasitic to the system and fluctuations evolve self-consistently. Finally, turbulent diffusion in CSDX follows the scaling: DCSDX=DBρ⋆0.6, where DB is the Bohm diffusion coefficient and ρ⋆ is the ion gyroradius normalized to the density gradient |∇n¯/n¯| −1.