bluuebunny/crossref_metadata_2025 huggingface dataset:
Medial Femoral Trochlea Osteochondral Graft: A Quantitative Anatomic Comparison to the Proximal Pole of the Scaphoid
Authors: Hill J. Ryan , Heckmann Nathanael , McKnight Braden , White Eric A. , Ghiassi Alidad , Patel Biren A.
Published: April 2020

Background Treatment of scaphoid proximal pole (SPP) nonunion with a vascularized osteochondral graft from the medial femoral trochlea (MFT) has been described, with positive outcomes thus far. However, our understanding of the congruency between the articular surfaces of these structures is incomplete.

Objective Our purpose was to evaluate the congruency of the MFT and SPP using a quantitative anatomical approach.

Methods The distal femur and ipsilateral scaphoid were dissected from 12 cadavers and scanned with computerized tomography. Three-dimensional models were created and articular surfaces were digitally “dissected.” The radius of curvature (RoC) of the radioulnar (RU) and proximodistal (PD) axes of the SPP and MFT, respectively, as well as the orthogonal axes (SPP, anteroposterior [AP]; MFT, mediolateral [ML]) were calculated. The RoC values were compared using the Wilcoxon signed-rank test.

Results The RoC values for the SPP and MFT were not significantly different in the RU–PD plane (p = 0.064). However, RoC values for the SPP and MFT were significantly different in the AP-ML plane (p = 0.001).

Conclusions For most individuals, the RU curvature of the SPP was similar to the PD curvature of the MFT. For nearly all individuals, the AP curvature of the SPP and the ML curvature of the MFT shared less congruence.

Clinical Relevance Articular surface congruity may not be a critical factor associated with improvements in wrist function following this procedure.
Arthroscopic Removal of a Screwdriver Fragment in a Dog 6 Years after Femoral Fracture Repair
Authors: Petazzoni Massimo
Published: April 2020

Objective The aim of this study was to report an unusual case of an iatrogenic foreign body within the stifle joint, removed 6 years after distal femoral fracture repair in a small dog. Acute lameness was caused by a migrating screwdriver fragment, which had been lost during initial fracture repair and which did not cause clinical signs for years until dislodged inside the joint.

Case Report A male Jack Russell, 7 years of age, underwent plate and screws fixation to treat a Salter-Harris type I fracture at the age of 9 months. Seven months after surgery, partial implant removal was performed. Six years after fracture repair, the dog presented for a non-weight-bearing lameness and pain on the previously operated stifle joint, which occurred suddenly while walking on the leash. Radiographs revealed a small intra-articular metallic radiodense foreign body. Arthroscopy was used to remove the migrating broken-tip of a screwdriver from the medial aspect of the tibiofemoral joint. Retrieving the foreign body led to the immediate resolution of clinical signs without complications.

Conclusion By reporting this case of a forgotten foreign body retained inside a stifle joint for 6 years, we aim to illustrate the potential risk of leaving a piece of metal inside the body. A high index of suspicion for such complications should be kept a long time after surgery. Arthroscopy was a useful first-line tool for efficiently and mini-invasively treating this unusual problem.
Large and Uneven Bites in End-to-End Anastomosis of the Rat Femoral Artery
Authors: Zheng Yuan Dian , Nicolas Celine F. , Corvi John J. , Kurtzman Joey S. , Park Katherine H. , Coley Shana M. , Marboe Charles C. , Akelina Yelena , Strauch Robert J.
Published: April 2020

Background Successful microvascular anastomosis depends on sutures that adequately oppose both cut vessel edges. Trainees tend to take oversized or uneven bite. To improve early microsurgical skill acquisition using the rat, this study tests the belief that such bites compromise early patency by applying exaggerated bites to end-to-end arterial anastomoses.

Methods Twelve Sprague–Dawley rats were randomly assigned to one of the four bite techniques to be applied to both femoral arteries (mean diameter, 0.8 mm). Large (L) and standard (S) bites measured 1.0 and 0.2 mm from the edge, respectively. Eight simple interrupted anastomoses were performed per bite technique, each labeled according to every proximal end bite size, followed by every distal end bite size: LL, LS, SL, and SS. Anastomosis time and blood flow rates were recorded and analyzed statistically. After sacrifice 5 days postoperation, anastomosis sections of each technique were examined histologically.

Results All 24 anastomoses (100%) maintained patency for 5 days. There was no statistical difference between all postoperative blood flow measurements at any given time. Anastomosis times using LL, LS, SL, and SS bite techniques were 41.6, 33.2, 34.8, and 25.5 minutes, respectively. Anastomosis time for the traditional bite technique (SS) was significantly shorter than all other bite techniques (p < 0.05). Histological examination of the harvested segments from each group revealed similar pathophysiological features.

Conclusion Oversized bites (1 mm), placed symmetrically and asymmetrically across the anastomosis, do not affect early patency in the rat femoral artery. A reduced reliance on conventional guidelines for suture bites appears acceptable during microarterial anastomoses if the goal is vessel patency. However, we believe clinical competence involves the ability to place small, even bites consistently and uniformly. During microsurgical training, the occasional large bite need not be replaced; however, the trainee should be encouraged to take standard bites.
Simultaneous Opponensplasty and Free Gracilis Muscle Flap for Thenar Reconstruction after Arteriovenous Malformation Resection
Authors: Garcia-Vilariño Elena , Thione Alessandro , Salmeron-Gonzalez Enrique , Sanchez-Garcia Alberto , Perez-Garcia Alberto
Published: April 2020

We report the case of a thenar eminence arteriovenous malformation presenting with continuous growth and pain that was treated with surgical excision after embolization. Extracapsular resection compromised thenar muscles which function was reconstructed with extensor indicis proprius transfer for opposition and abduction, and neurotized free gracilis muscle flap for opposition and adduction, as well as thenar eminence reconstruction.
A simplified cryogenic optical resonator apparatus providing ultra-low frequency drift
Authors: Wiens Eugen , Kwong Chang Jian , Müller Timo , Schiller Stephan
Published: April 2020

A system providing an optical frequency with instability comparable to that of a hydrogen maser is presented. It consists of a 5 cm long, vertically oriented silicon optical resonator operated at temperatures between 1.5 K and 3.6 K in a closed-cycle cryostat with a low-temperature Joule–Thomson stage. We show that with a standard cryostat, a simple cryogenic optomechanical setup, and no active or passive vibration isolation, a minimum frequency instability of 2.5 × 10−15 at τ = 1500 s integration time can be reached. The influence of pulse-tube vibrations was minimized by using a resonator designed for low acceleration sensitivity. With reduced optical laser power and interrogation duty cycle, an ultra-low fractional frequency drift of −2.6 × 10−19/s is reached. At 3.5 K, the resonator frequency exhibits a vanishing thermal sensitivity and an ultra-small temperature derivative 8.5 × 10−12/K2. These are favorable properties that should lead to high performance also in simpler cryostats not equipped with a Joule–Thomson stage.
A simple extended-cavity diode laser using a precision mirror mount
Authors: Yim Sin Hyuk , Kim Tae Hyun , Choi Jai-Min
Published: April 2020

We have developed an extended-cavity diode laser (ECDL) with a simple design by using a commercial precision mirror mount with minor modifications. Our design allows tuning of the external cavity configuration by tweaking the volume holographic grating without troublesome changes in the beam path of the laser output. The mode-hop-free tuning range of the presented ECDL is about 8 GHz with a linewidth of 475 kHz.
[(FeCoB/Ru/FeCoB)/ZnO]n superlattice multilayer: A real optical mode ferromagnetic resonance thick-film
Authors: Du Honglei , Xue Qian , Li Shandong , Miao Guo-Xing , Chu Xian-Ming , Dai Youyong , Yu Meijie , Zhao Guoxia , Yan Shishen
Published: April 2020

A pure optical mode (OM) resonance with ultrahigh resonance frequency (frO) and permeability μ at zero bias field was observed in 50-nm FeCoB/Ru/FeCoB sandwich trilayers due to the presence of strong antiferromagnetic interlayer exchange coupling. However, the necessary thickness for creating practical microwave devices cannot be readily achieved by increasing the FeCoB layer thickness or stacking FeCoB/Ru units due to dramatically deteriorated high-frequency performance. In this study, several 50-nm FeCoB/Ru/FeCoB OM units were stacked to form a superlattice structure, with 10-nm ZnO insulator spacers separating the units. It is interesting that the superlattice multilayers not only retain excellent high-frequency OM resonance performance comparable to the single OM unit but also increase the effective magnetic film thickness by a factor of 5. This can be attributed to the positive superposition of the almost identical OM units as well as the effective decoupling between them by thick ZnO spacers. This study provides a promising way to fabricate thicker films while still maintaining excellent OM resonance performance.
Linear dispersion theory of parallel electromagnetic modes for regularized Kappa-distributions
Authors: Husidic Edin , Lazar Marian , Fichtner Horst , Scherer Klaus , Astfalk Patrick
Published: April 2020

The velocity particle distributions measured in situ in space plasmas deviate from Maxwellian (thermal) equilibrium, showing enhanced suprathermal tails that are well described by the standard Kappa-distribution (SKD). Despite its successful application, the SKD is frequently disputed due to a series of unphysical implications such as diverging velocity moments, preventing a macroscopic description of the plasma. The regularized Kappa-distribution (RKD) has been introduced to overcome these limitations, but the dispersion properties of RKD-plasmas have not yet been explored. In the present paper, we compute the wavenumber dispersion of the frequency and damping or growth rates for the electromagnetic modes in plasmas characterized by the RKD. This task is accomplished by using the grid-based kinetic dispersion solver LEOPARD (“Linear Electromagnetic Oscillations in Plasmas with Arbitrary Rotationally symmetric Distributions”) developed for arbitrary gyrotropic distributions [P. Astfalk and F. Jenko, J. Geophys. Res. 122, 89 (2017)]. By reproducing previous results obtained for the SKD and Maxwellian, we validate the functionality of the code. Furthermore, we apply the isotropic and anisotropic RKDs to investigate stable electromagnetic electron-cyclotron (EMEC) and ion-cyclotron (EMIC) modes, as well as temperature-anisotropy-driven instabilities, for both T⊥/T∥>1 (EMEC and EMIC instabilities) and T⊥/T∥<1 cases (proton and electron firehose instabilities), where ∥ and ⊥ denote directions parallel and perpendicular to the local time-averaged magnetic field. Provided that the cutoff parameter α is small enough, the results show that the RKDs reproduce the dispersion curves of the SKD plasmas at both qualitative and quantitative levels. For higher values, however, a physically significant deviation occurs.
Stacking order driving bandgap and conductance of graphene/C3B (C3N) van der Waals heterostructures
Authors: Kang Dawei , Zuo Zheng-Wei , Zhang Shuai , Wang Zhaowu , Zhang Longlong
Published: April 2020

Constructing a van der Waals (vdW) heterostructure is a promising approach to tackle the bandgap hurdle of graphene meanwhile preserving its excellent electronic properties. The unique symmetry of atomic arrangement in C3B and C3N monolayers could induce interesting properties in the graphene/C3B (C3N) heterostructure. Based on the density functional theory calculation, we demonstrate that the bandgap near the Dirac cone depends sensitively on the stacking order in the graphene/C3B (C3N) vdW heterostructure. The bandgap is opened in the AB stacking order, but is completely closed in the AA stacking order. The bandgap closing is protected by the AA stacking order even under vertical strain, while the bandgap increases in the AB stacking order with a positive vertical strain. Based on the tight-binding model, the origin of the bandgap opening and closing is explained by the stacking-order dependent charge transfer. Moreover, the transport properties of the devices assembled by the graphene/C3B vdW heterostructures are investigated based on the non-equilibrium Green's function method plus the density functional theory. The conductance can be turned on or off depending on the stacking order. This finding is useful for the future design of on/off devices based on graphene/C3B (C3N) heterostructures.
Accuracy of genomic prediction using mixed low-density marker panels
Authors: Hou Lianjie , Liang Wenshuai , Xu Guli , Huang Bo , Zhang Xiquan , Hu Ching Yuan , Wang Chong
Published: April 2020

Low-density single-nucleotide polymorphism (LD-SNP) panel is one effective way to reduce the cost of genomic selection in animal breeding. The present study proposes a new type of LD-SNP panel called mixed low-density (MLD) panel, which considers SNPs with a substantial effect estimated by Bayes method B (BayesB) from many traits and evenly spaced distribution simultaneously. Simulated and real data were used to compare the imputation accuracy and genomic-selection accuracy of two types of LD-SNP panels. The result of genotyping imputation for simulated data showed that the number of quantitative trait loci (QTL) had limited influence on the imputation accuracy only for MLD panels. Evenly spaced (ELD) panel was not affected by QTL. For real data, ELD performed slightly better than did MLD when panel contained 500 and 1000 SNP. However, this advantage vanished quickly as the density increased. The result of genomic selection for simulated data using BayesB showed that MLD performed much better than did ELD when QTL was 100. For real data, MLD also outperformed ELD in growth and carcass traits when using BayesB. In conclusion, the MLD strategy is superior to ELD in genomic selection under most situations.
Deer blood effectively improved clinical signs of anaemia in a rodent model
Authors: Qi Xiaoyan , Zhao Haiping , Shang Yudong , Xu Yuan , Yao Mengjie , Wang Changfeng , Hu Pengfei , Li Chunyi
Published: April 2020

Iron-deficiency anaemia (IDA) is one of the most common health problems in the world. As a type of traditional Chinese medicine, deer blood (DB) is often used to treat IDA in China. However, no scientifically designed studies with strict controls were available for the evaluation of therapeutic effects of DB on IDA. In the present study, IDA rat model was first established through feeding iron-deficient diet and then three doses of DB treatment (low, mid and high) were used to feed these rats. During the 30-day treatment period, body condition of the negative-control rats continued to decline. There was no significant difference among the groups of DB-high, positive control and overall intact control in haemoglobin concentration, haematocrit concentration and the number of red blood cells. Results showed that both groups DB-mid and DB-high showed significantly increased iron concentrations in the three organs including liver, spleen and kidney of the rats, compared with all other groups, including the positive-control group. We believe our study has opened a new avenue for the development of DB as a drug to treat IDA in clinics.
Moderation of mitochondrial respiration mitigates metabolic syndrome of aging
Authors: Tavallaie Mojdeh , Voshtani Ramouna , Deng Xinxian , Qiao Yixue , Jiang Faqin , Collman James P. , Fu Lei
Published: April 2020

Significance

The efforts toward minimizing oxidative stress and maintaining mitochondrial energy metabolism for promoted healthy aging are at the forefront of current research on aging. We have characterized a treatment that, by reversible inhibition of mitochondrial respiration in mice through cytochrome c oxidase (CcO), markedly improves mitochondrial bioenergetics and delays the lead health concerns associated with aging in mice. We demonstrated that chronic moderate inhibition of CcO reduces ATP synthesis, promotes mitochondrial biogenesis and mitophagy, subsequently decreases ROS production and mitochondrial decay, and rectifies vital cellular energy metabolism regulators, thus, effectively refining energy homeostasis and curbing obesity and glucose irregularities linked to aging.
The development of intonation in L2 Spanish
Authors: Brandl Anel , González Carolina , Bustin Amy
Published: April 2020

This study explores the perceptual development of
intonation in questions and statements in L2 Spanish. It presents
cross-sectional data from 189 L2 learners from five different
proficiency levels and 10 Spanish native controls. Participants
performed an intonation matching task consisting of deciding whether
sentences presented aurally and visually matched. Perception
accuracy and reaction time results are consistent with the gradual
acquisition of intonational cues, particularly for statements and
yes-no questions. Statements are identified faster and more
accurately than yes-no questions, suggesting that the latter are
harder to process and acquire. Consistent with Trimble (2013) and Nibert (2005, 2006), our findings suggest that
intermediate II learners are beginning to acquire the intonational
cues that distinguish statements from yes-no questions in
Spanish.
What derivational suffixes should we teach in Spanish as a Second
Language courses?
Authors: Sanchez-Gutierrez Claudia H. , Marcos Nausica , Robles García Pablo
Published: April 2020

Morphological awareness in a second language (L2)
enhances depth of vocabulary knowledge and is better developed when
taught explicitly than by mere exposure to morphologically complex
words. However, suffixes are not sufficiently treated in L2
textbooks, and little is known about which suffixes should be taught
and which suffixes are more easily learned. Based on a corpus
analysis of Spanish L1 and L2 speakers, as well as a correlational
study about the characteristics of Spanish suffixes, this paper
proposes 12 derivational suffixes that should be introduced in
Spanish L2 classrooms.
Futurity and probability in Spanish as a heritage
language
Authors: Pascual y Cabo Diego , Vela Gema
Published: April 2020

Focusing on Spanish future morphology as the property
under investigation, this study contributes to the literature on
heritage speaker bilingualism by exploring whether adult Spanish
heritage speakers are able to distinguish between its two possible
interpretations: temporal and epistemic. To this end, we present
production and comprehension data from adult heritage speakers as
well as from dialect-matched adult immigrants living in the United
States. While both groups show robust knowledge of future morphology
to express temporal futurity, our findings reveal significant
differences in their access to and production of the epistemic
interpretation. We document a case of convergent
simplification whereby the outcome observed constitutes a reduction
of the possibilities associated with future tense morphology to make
Spanish more similar to English.
Modality-specificity of iconicity
Authors: Akita Kimi
Published: April 2020

This study examines the semantic variety and specificity
of Japanese ideophones for spatial motion events to illustrate the
modality-specificity of iconicity. As verbal icons, motion
ideophones tend to depict dynamic (e.g., auditory, spatio-temporal)
aspects of motion events. Suprasegmental features that elaborate
ideophonic depiction also exhibit this tendency. In contrast, manual
icons, such as iconic gestures and sign language, are more
expressive of visual information, both dynamic and static. Motion
events, which involve various concepts, allow us to observe this
semiotic contrast clearly and reinforce the modality-specific view
of iconicity.
Iconicity in branding
Authors: Shibata Ayako
Published: April 2020

This paper demonstrates the complex iconicity of Japanese
whiskey by analysing brand identities represented on bottle designs
and advertisements. There are, chronologically, four phases in the
relationship between the names of products and the languages used on
the labels: (1) the application of Japanese names which were not
specified on the labels in English; (2) the usage of only English
names and logos; (3) the commencement of Japanese names on the
labels in Japanese calligraphy and (4) the utilisation of both
Japanese and English names and logos depending on the marketing
strategies. This study focusses on Phase 3 in order to identify how
graphic images of Japanese calligraphy and other design features
iconise the brand identities. It is thus argued that iconic effect
is a powerful branding device for establishing the convincing image
of Japanese whiskey in the global marketing context.
The cognitive function of iconicity
Authors: Santaella Lucia
Published: April 2020

Unfortunately, Peirce’s concept of the icon has been
reduced to the notion of a sign that represents its object by
similarity. It is true that Peirce considered a subdivision of the
icons into the image, the diagram, and the metaphor, which reveal
other facets of this sign type. However, even this subdivision does
not exhaust the whole picture of iconicity. Although no explicit
systematization can be found in Peirce’s work, the distinction
between pure icon on the one hand and actual icons on the other are
clearly drawn in some passages of his writings. The aim of this
paper is to discuss these passages in order to stress that the
notions of pure icon, actual icons, and hypoicons fit perfectly well
in the logical framework of the categories of Firstness, Secondness,
and Thirdness. Then, the distinct perceptual and cognitive functions
of these facets of iconicity will be explored.
Computational phraseology discovery in corpora with the
mwetoolkit
Authors: Ramisch Carlos
Published: April 2020

Computer tools can help discovering new phraseological units in
corpora, thanks to their ability to quickly draw statistics from large
amounts of textual data. While the research community has focused on
developing and evaluating original algorithms for the automatic discovery of
phraseological units, little has been done to transform these sophisticated
methods into usable software. In this chapter, we present a brief survey of
the main approaches to computational phraseology available. Furthermore, we
provide worked out examples of how to apply these methods using the
mwetoolkit, a free software for the discovery and identification of
multiword ex-pressions. The usefulness of the automatically extracted units
depends on various factors such as language, corpus size, target units, and
available taggers and parsers. Nonetheless, the mwetoolkit allows
fine-grained tuning so that this variability is taken into account, adapting
the tool to the specificities of each lexicographic environment.
Verbal collocations and pronominalisation
Authors: Wehrli Eric , Seretan Violeta , Nerima Luka
Published: April 2020

Precise identification of multiword expressions (MWEs) is an
important qualitative step for several NLP applications, including machine
translation. Since most MWEs cannot be translated literally, failure to
identify them yields, at best, inaccurate translation. While some
expressions are completely frozen and thus can be listed as compound words,
others display a sometimes very large degree of syntactic flexibility.

In this chapter, we argue not only that structural information is
necessary for an adequate treatment of collocations, but also that the
detection of collocations can be useful for the parser. For instance, it is
very useful for solving part-of-speech ambiguities and also some attachment
ambiguities. We therefore claim that collocation identification and parsing
are interrelated processes.

Section 2 describes the
two processes of parsing and collocation detection and their interaction,
(i) when and how the collocation identification process is triggered during
parsing, and (ii) how the identification of a collocation helps the parser.
In Section 3 we describe how
anaphora resolution has been implemented in our parsing system, to handle
cases where the antecedent and the pronoun are within the same sentence or
in adjacent sentences. Section 4
focuses on more intricate cases of verbal collocations where their nominal
element has been pronominalised, in the form of a relative pronoun or a
personal pronoun. Verb-object collocations with a relative pronoun are
extremely frequent and relatively easy to handle for a “deep” parser. In
most cases, the relative clause is directly attached to the noun which is
part of the collocation. Collocations in which the nominal element takes the
form of a personal pronoun are much harder to deal with, as they depend on
the process of anaphora resolution, a very challenging task. The last
section describes an evaluation of the collocation detection procedure,
enhanced with anaphora resolution using a corpus of newspaper articles of
about 10 million words.
Isoimperatorin (ISO) reduces melanin content in keratinocytes via miR-3619/CSTB and miR-3619/CSTD axes
Authors: Zeng Bijun , Li Kai , Yang Zhibo , Wang Haizhen , Wang Chang , Huang Pan , Pan Yi
Published: April 2020

Melanin metabolism disorders may cause severe impacts on the psychological and social activities of patients. Different from the other two steps of melanin metabolism, namely synthesis and transport, little has been known about the mechanism of melanin degradation. Isoimperatorin (ISO) suppressed the activity of tyrosinase, an essential enzyme in melanin biosynthesis, hence, we investigated the effects and mechanism of ISO in melanin reduction. ISO stimulation significantly reduces the melanin contents and PMEL 17 protein levels; meanwhile, the activity and the protein levels of two critical lysosomal enzymes, Cathepsin B and Cathepsin D, can be significantly increased by ISO treatment. MiR-3619 inhibited the expression of CSTB and CSTD, therefore affecting ISO-induced degradation of melanin. In summary, ISO reduces the melanin content via miR-3619/CSTB and miR-3619/CSTD axes. ISO could be a potent skin-whitening agent, which needs further in vivo and clinical investigation.
Isometries from gauge transformations
Authors: Frodden Ernesto , Krasnov Kirill
Published: April 2020

In four dimensions one can use the chiral part of the spin connection as the main object that encodes geometry. The metric is then recovered algebraically from the curvature of this connection. We address the question of how isometries can be identified in this ‘pure connection’ formalism. We show that isometries are recovered from gauge transformation parameters satisfying the requirement that the Lie derivative of the connection along a vector field generating an isometry is a gauge transformation. This requirement can be rewritten as a first order differential equation involving the gauge transformation parameter only. Once a gauge transformation satisfying this equation is found, the isometry generating vector field is recovered algebraically. We work out examples of the new formalism being used to determine isometries, and also prove a general statement: a negative definite connection on a compact manifold does not have symmetries. This is the precise ‘pure connection’ analog of the well-known Riemannian geometry statement that there are no Killing vector fields on compact manifolds with negative Ricci curvature.
Anomalous pressure dependence of the electronic transport and anisotropy in SrIrO3 films
Authors: Zaitsev A G , Beck A , Jaiswal A K , Singh R , Schneider R , Le Tacon M , Fuchs D
Published: April 2020

Iridate oxides display exotic physical properties that arise from the interplay between a large spin–orbit coupling and electron correlations. Here, we present a comprehensive study of the effects of hydrostatic pressure on the electronic transport properties of SrIrO3 (SIO), a system that has recently attracted a lot of attention as potential correlated Dirac semimetal. Our investigations on untwinned thin films of SIO reveal that the electrical resistivity of this material is intrinsically anisotropic and controlled by the orthorhombic distortion of the perovskite unit cell. These effects provide another evidence for the strong coupling between the electronic and lattice degrees of freedom in this class of compounds. Upon increasing pressure, a systematic increase of the transport anisotropies is observed. The anomalous pressure-induced changes of the resistivity cannot be accounted for by the pressure dependence of the density of the electron charge carriers, as inferred from Hall effect measurements. Moreover, pressure-induced rotations of the IrO6 octahedra likely occur within the distorted perovskite unit cell and affect electron mobility of this system.
Mode properties of telecom wavelength InP-based high-(Q/V) L4/3 photonic crystal cavities
Authors: Rickert L , Fritsch B , Kors A , Reithmaier J P , Benyoucef M
Published: April 2020

We present finite-difference time domain simulations and optical characterizations via micro-photoluminescence measurements of InP-based L4/3 photonic crystal cavities with embedded quantum dots (QDs) and designed for the M1 ground mode to be emitting at telecom C-band wavelengths. The simulated M1 Q-factor values exceed 106, while the M1 mode volume is found to be 0.33 × (λ/n)3, which is less than half the value of the M1 mode volume of a comparable L3 cavity. Low-temperature micro-photoluminescence measurements revealed experimental M1 Q-factor values on the order of 104 with emission wavelengths around 1.55 μm. Weak coupling behavior of the QD exciton line and the M1 ground mode was achieved via temperature-tuning experiments.
Optical storage for 0.53 s in a solid-state atomic frequency comb memory using dynamical decoupling
Authors: Holzäpfel Adrian , Etesse Jean , Kaczmarek Krzysztof T , Tiranov Alexey , Gisin Nicolas , Afzelius Mikael
Published: April 2020

Quantum memories with long storage times are key elements in long-distance quantum networks. The atomic frequency comb (AFC) memory in particular has shown great promise to fulfill this role, having demonstrated multimode capacity and spin–photon quantum correlations. However, the memory storage times have so-far been limited to about 1 ms, realized in a Eu3+ doped Y2SiO5 crystal at zero applied magnetic field. Motivated by studies showing increased spin coherence times under applied magnetic field, we developed an AFC spin-wave memory utilizing a weak 15 mT magnetic field in a specific direction that allows efficient optical and spin manipulation for AFC memory operations. With this field configuration the AFC spin-wave storage time increased to 40 ms using a simple spin-echo sequence. Furthermore, by applying dynamical decoupling techniques the spin-wave coherence time reaches 530 ms, a 300-fold increase with respect to previous AFC spin-wave storage experiments. This result paves the way towards long duration storage of quantum information in solid-state ensemble memories.
Efficient orbital imaging based on ultrafast momentum microscopy and sparsity-driven phase retrieval
Authors: Jansen G S M , Keunecke M , Düvel M , Möller C , Schmitt D , Bennecke W , Kappert F J S , Steil D , Luke D R , Steil S , Mathias S
Published: April 2020

We present energy-resolved photoelectron momentum maps for orbital tomography that have been collected with a novel and efficient time-of-flight momentum microscopy setup. This setup is combined with a 0.5 MHz table-top femtosecond extreme-ultraviolet light source, which enables unprecedented speed in data collection and paves the way towards time-resolved orbital imaging experiments in the future. Moreover, we take a significant step forward in the data analysis procedure for orbital imaging, and present a sparsity-driven approach to the required phase retrieval problem, which uses only the number of non-zero pixels in the orbital. Here, no knowledge of the object support is required, and the sparsity number can easily be determined from the measured data. Used in the relaxed averaged alternating reflections algorithm, this sparsity constraint enables fast and reliable phase retrieval for our experimental as well as noise-free and noisy simulated photoelectron momentum map data.
Randomized benchmarking for qudit Clifford gates
Authors: Jafarzadeh Mahnaz , Wu Ya-Dong , Sanders Yuval R , Sanders Barry C
Published: April 2020

We introduce unitary-gate randomized benchmarking (URB) for qudit gates by extending single- and multi-qubit URB to single- and multi-qudit gates. Specifically, we develop a qudit URB procedure that exploits unitary 2-designs. Furthermore, we show that our URB procedure is not simply extracted from the multi-qubit case by equating qudit URB to URB of the symmetric multi-qubit subspace. Our qudit URB is elucidated by using pseudocode, which facilitates incorporating into benchmarking applications.
Revisiting turbulence small-scale behavior using velocity gradient triple decomposition
Authors: Das Rishita , Girimaji Sharath S
Published: April 2020

Turbulence small-scale behavior has been commonly investigated in literature by decomposing the velocity-gradient tensor (A

ij
) into the symmetric strain-rate (S

ij
) and anti-symmetric rotation-rate (W

ij
) tensors. To develop further insight, we revisit some of the key studies using a triple decomposition of the velocity-gradient tensor. The additive triple decomposition formally segregates the contributions of normal-strain-rate (N

ij
), pure-shear (H

ij
) and rigid-body-rotation-rate (R

ij
). The decomposition not only highlights the key role of shear, but it also provides a more accurate account of the influence of normal-strain and pure rotation on important small-scale features. First, the local streamline topology and geometry are described in terms of the three constituent tensors in velocity-gradient invariants’ space. Using direct numerical simulation (DNS) data sets of forced isotropic turbulence, the velocity-gradient and pressure field fluctuations are examined at different Reynolds numbers. At all Reynolds numbers, shear contributes the most and rigid-body-rotation the least toward the velocity-gradient magnitude (A
2 ≡ A

ij

A

ij
). Especially, shear contribution is dominant in regions of high values of A
2 (intermittency). It is shown that the high-degree of enstrophy intermittency reported in literature is due to the shear contribution toward vorticity rather than that of rigid-body-rotation. The study also provides an explanation for the non-intermittent nature of pressure-Laplacian, despite the strong intermittency of enstrophy and dissipation fields. The study further investigates the alignment of the rotation axis with normal strain-rate and pressure Hessian eigenvectors. Overall, it is demonstrated that triple decomposition offers unique and deeper understanding of velocity-gradient behavior in turbulence.
A comprehensive neural networks study of the phase transitions of Potts model
Authors: Tan D-R , Li C-D , Zhu W-P , Jiang F-J
Published: April 2020

Using the techniques of neural networks (NN), we study the three-dimensional (3D) five-state ferromagnetic Potts model on the cubic lattice as well as the two-dimensional (2D) three-state antiferromagnetic Potts model on the square lattice. Unlike the conventional approach, here we follow the idea employed by Li et al (2018 Ann. Phys., NY
391 312–331). Specifically, instead of numerically generating numerous objects for the training, the whole or part of the theoretical ground state configurations of the studied models are considered as the training sets. Remarkably, our investigation of these two models provides convincing evidence for the effectiveness of the method of preparing training sets used in this study. In particular, the results of the 3D model obtained here imply that the NN approach is as efficient as the traditional method since the signal of a first order phase transition, namely tunneling between two channels, determined by the NN method is as strong as that calculated with the Monte Carlo technique. Furthermore, the outcomes associated with the considered 2D system indicate even little partial information of the ground states can lead to conclusive results regarding the studied phase transition. The achievements reached in our investigation demonstrate that the performance of NN, using certain amount of the theoretical ground state configurations as the training sets, is impressive.
Quantum secure direct communication based on single-photon Bell-state measurement
Authors: Li Tao , Long Gui-Lu
Published: April 2020

Security loopholes exploiting the flaws of practical apparatus, especially non-ideal photon detectors, are pressing issues in practical quantum communication. We propose a simple quantum secure direct communication protocol based on single-photon Bell-state measurement and remove side-channel attacks on photon detectors. This quantum communication protocol in principle works in a deterministic way, and it does not require the two-photon interference of photons from independent sources. The single-photon Bell-state measurement with a unity efficiency can be constructed with only linear optics, which significantly simplifies its experimental implementation. Furthermore, we prove that our quantum secure direct communication protocol is immune to general detector-side-channel attacks.
ATLAS muon trigger performance
Authors: Ventura Andrea
Published: April 2020

Muons in the final state represent an important signature for many physics studies performed at the Large Hadron Collider (LHC), involving analyses on Standard Model measurements and on new physics searches. An optimized selection of such events requires an efficient and deeply understood muon trigger system. The present work describes the ATLAS muon trigger, consisting of a hardware-based system (Level-1) followed by a software-based reconstruction (High-Level Trigger). To handle the increase of luminosity in Run 2, several upgrades have been implemented to reduce the trigger rate, while still maintaining high values for the efficiency. Such improvements include the request of a coincidence of hits in the muon spectrometer and the hadronic tile calorimeter, an optimised muon isolation and a better estimation of transverse momentum. An overview will be presented on the most recent improvements of the ATLAS muon trigger and on its performance during Run 2. Finally an outlook for the most relevant upgrades planned for Run 3 will be reported.
Photoluminescence in wide band gap corundum Mg4Ta2O9 single crystals*
Authors: Li Liang , Zheng Yu-Lu , Hu Yu-Xin , Li Fang-Fei , Zhou Qiang , Cui Tian
Published: April 2020

As is well known, the basic intrinsic properties of materials can be significant for their practical applications. In this work, the room-temperature absorption, transmittance, reflectance spectra, and relative photoelectricities parameters of the Mg4Ta2O9 crystals are demonstrated. Meanwhile, the polarized Raman spectra of Mg4Ta2O9 crystals are also described. The room-temperature photoluminescence (PL) and the temperature-dependent PL for Mg4Ta2O9 crystals are obtained. Significantly, we observe a phonon-participated PL process in Mg4Ta2O9.
Temperature dependence of mode coupling effect in piezoelectric vibrator made of [001]c-poled Mn-doped 0.24PIN–0.46PMN–0.30PT ternary single crystals with high electromechanical coupling factor*
Authors: Huang Nai-Xing , Sun En-Wei , Zhang Rui , Yang Bin , Liu Jian , Lü Tian-Quan , Cao Wen-Wu
Published: April 2020

The influence of temperature on mode coupling effect in piezoelectric vibrators remains unclear. In this work, we discuss the influence of temperature on two-dimensional (2D) mode coupling effect and electromechanical coupling coefficient of cylindrical [001]
c
-poled Mn-doped 0.24PIN–0.46PMN–0.30PT piezoelectric single-crystal vibrator with an arbitrary configuration ratio. The electromechanical coupling coefficient k
t decreases with temperature increasing, whereas k
33 is largely invariant in a temperature range of 25 °C–55 °C. With the increase of temperature, the shift in the ‘mode dividing point’ increases the scale of the poling direction of the piezoelectric vibrator. The temperature has little effect on coupling constant Γ. At a given temperature, the coupling constant Γ of the cylindrical vibrator is slightly greater than that of the rectangular vibrator. When the temperature changes, the applicability index (M) values of the two piezoelectric vibrators are close to 1, indicating that the coupling theory can be applied to piezoelectric vibrators made of late-model piezoelectric single crystals.
Finite density scaling laws of condensation phase transition in zero-range processes on scale-free networks*
Authors: Su Guifeng , Li Xiaowen , Zhang Xiaobing , Zhang Yi
Published: April 2020

The dynamics of zero-range processes on complex networks is expected to be influenced by the topological structure of underlying networks. A real space complete condensation phase transition in the stationary state may occur. We study the finite density effects of the condensation transition in both the stationary and dynamical zero-range processes on scale-free networks. By means of grand canonical ensemble method, we predict analytically the scaling laws of the average occupation number with respect to the finite density for the steady state. We further explore the relaxation dynamics of the condensation phase transition. By applying the hierarchical evolution and scaling ansatz, a scaling law for the relaxation dynamics is predicted. Monte Carlo simulations are performed and the predicted density scaling laws are nicely validated.
Improved hybrid parallel strategy for density matrix renormalization group method*
Authors: Chen Fu-Zhou , Cheng Chen , Luo Hong-Gang
Published: April 2020

We propose a new heterogeneous parallel strategy for the density matrix renormalization group (DMRG) method in the hybrid architecture with both central processing unit (CPU) and graphics processing unit (GPU). Focusing on the two most time-consuming sections in the finite DMRG sweeps, i.e., the diagonalization of superblock and the truncation of subblock, we optimize our previous hybrid algorithm to achieve better performance. For the former, we adopt OpenMP application programming interface on CPU and use our own subroutines with higher bandwidth on GPU. For the later, we use GPU to accelerate matrix and vector operations involving the reduced density matrix. Applying the parallel scheme to the Hubbard model with next-nearest hopping on the 4-leg ladder, we compute the ground state of the system and obtain the charge stripe pattern which is usually observed in high temperature superconductors. Based on simulations with different numbers of DMRG kept states, we show significant performance improvement and computational time reduction with the optimized parallel algorithm. Our hybrid parallel strategy with superiority in solving the ground state of quasi-two dimensional lattices is also expected to be useful for other DMRG applications with large numbers of kept states, e.g., the time dependent DMRG algorithms.
Viscous dissipation effect on Williamson nanofluid over stretching/shrinking wedge with thermal radiation and chemical reaction
Authors: Ibrahim Wubshet , Negera Mekonnen
Published: April 2020

This paper scrutinizes the effect of viscous dissipation on unsteady two-dimensional boundary layer flow of Williamson nanofluid over a stretching/Shrinking wedge. To express the boundary condition in concentration problem the passive control concept used. The governing PDEs are converted to ODEs by means of a similarity transformation before being solved numerically by finite difference scheme called Keller-Box method. The equations were numerically solved by using Matlab software 2013a. The characteristics of parameters such as wedge angle, unsteadiness, Williamson, slip, Brownian motion, thermophoresis, chemical reaction parameters, Prandtl number, Biot-number, Eckert number and Lewis number on velocity, concentration and temperature profiles and skin friction coefficient, Nusselt number and Sherwood number are presented in graphs and tables. The result of the study designates that the velocity profiles increased with an upsurge of wedge angle, unsteady parameter and suction parameter while it is diminished with an increase of Williamson and injection parameter. The temperature profiles upsurges with the distended Williamson parameter, Biot number and injection parameter, while it is declined for large values of wedge angle, unsteady and suction parameter. With an increase of Williamson, unsteady and suction parameter the concentration profiles upsurges, while it is decreased with an increase of wedge angle and injection parameter. The numerical results are compared with available literature and obtained a good agreement.
Low oxygen pressure synthesis of NdNiO3-δ nanowires by electrospinning
Authors: Medina M S , Ramirez B N , Ferreira P M G L , Huang H P , Zenatti A , Lanfredi A J C , Escote M T
Published: April 2020

Synthesis of RNiO3 (R = rare earth) nanowires can be interesting as building blocks with potential applications in optoelectronic devices. Here, we describe the synthesis and characterization of NdNiO3-δ
(NNO) nanowires produced by electrospinning technique via polymeric precursor solution at relatively low temperature and oxygen pressure. These NNO nanowires were characterized by x-ray diffraction (XRD), x-ray photodetection spectroscopy (XPS), Field Emission Scanning Electron Microscopy (Fe-SEM), Magnetization (M(T)) and electrical resistance (R(T)) measurements. SEM images revealed a granular nanowire microstructure of NNO nanostructures, with a distribution of nanowire diameters ranging from 50 to 150 nm. The NNO nanowires also exhibit granular characteristics with an average grain diameter of  40 nm. The x-ray diffraction patterns of the NNO nanowires indicated that these samples exhibited a high degree of crystallinity and their Bragg reflections can be indexed to an orthorhombic-distorted (Pbnm symmetry) perovskite structure. The crystalline structure seems to be slightly texturized in some Bragg directions and with a slightly strained crystallite. M(T) and R(T) measurement as a function of temperature curves show that these NNO samples present a metal-insulator (MI) transition close to T

MI
 ∼ 198 K, which is usually observed in NNO thin films and bulk samples. The nanostructured shape and these experimental observations can be promising in designing new electronic devices using this strongly correlated oxide.