bluuebunny/crossref_metadata_2025 huggingface dataset:
Energetic effects of hybrid organic/inorganic interfacial architecture on nanoporous black silicon photoelectrodes
Authors: Pekarek Ryan T. , Christensen Steven T. , Liu Jun , Neale Nathan R.
Published: March 2019

Interfacial layers on semiconductor surfaces in fuel-forming photoelectrochemical cells effect both energetic tuning and corrosion protection of the underlying semiconductor.
Piperidinium-functionalized anion exchange membranes and their application in alkaline fuel cells and water electrolysis
Authors: Chu Xiaomeng , Shi Yan , Liu Lei , Huang Yingda , Li Nanwen
Published: March 2019

A series of piperidinium-functionalized anion exchange membranes have been designed and fabricated for alkaline fuel cells and water electrolysis.
A novel information storage and visual expression device based on mechanoluminescence
Authors: Zuo Yong , Xu Xiaojie , Tao Xin , Shi Xiang , Zhou Xufeng , Gao Zhen , Sun Xuemei , Peng Huisheng
Published: March 2019

A novel information storage and visual expression device records the pre-stressed region and expresses the information via light emission.
Azadirachtin inhibits amyloid formation, disaggregates pre-formed fibrils and protects pancreatic β-cells from human islet amyloid polypeptide/amylin-induced cytotoxicity
Authors: Dubey Richa , Patil Ketaki , Dantu Sarath C. , Sardesai Devika M. , Bhatia Parnika , Malik Nikita , Acharya Jhankar D. , Sarkar Soham , Ghosh Soumadwip , Chakrabarti Rajarshi , Sharma Shilpy , Kumar Ashutosh
Published: February 2019

The human islet amyloid polypeptide (hIAPP) or amylin is the major constituent of amyloidogenic aggregates found in pancreatic islets of type 2 diabetic patients that have been associated with β-cell dysfunction and/or death associated with type 2 diabetes mellitus (T2DM). Therefore, developing and/or identifying inhibitors of hIAPP aggregation pathway and/or compound that can mediate disaggregation of preformed aggregates holds promise as a medical intervention for T2DM management. In the current study, the anti-amyloidogenic potential of Azadirachtin (AZD)—a secondary metabolite isolated from traditional medicinal plant Neem (Azadirachta indica)—was investigated by using a combination of biophysical and cellular assays. Our results indicate that AZD supplementation not only inhibits hIAPP aggregation but also disaggregates pre-existing hIAPP fibrils by forming amorphous aggregates that are non-toxic to pancreatic β-cells. Furthermore, AZD supplementation in pancreatic β-cells (INS-1E) resulted in inhibition of oxidative stress; along with restoration of the DNA damage, lipid peroxidation and the associated membrane damage, endoplasmic reticulum stress and mitochondrial membrane potential. AZD treatment also restored glucose-stimulated insulin secretion from pancreatic islets exposed to hIAPP. All-atom molecular dynamics simulation studies on full-length hIAPP pentamer with AZD suggested that AZD interacted with four possible binding sites in the amyloidogenic region of hIAPP. In summary, our results suggest AZD to be a promising candidate for combating T2DM and related amyloidogenic disorders.
Oil‐spill detection using hybrid‐pol data through reconstruction technique
Authors: Kumar A. , Panigrahi R.K.
Published: February 2019

Oil‐spill detection using hybrid‐pol data has been carried out through a novel ‐based reconstruction approach. Initially, the proposed ‐based method is experimented over two different datasets, which concludes that the proposed method is a better alternative for oil‐spill detection in comparison with conventional Souyris' and state‐of‐art Espeseth's reconstruction methods. Moreover, by utilising the ‐based method, a new oil spill index parameter is being proposed for oil‐spill detection.
Modified grey world method to detect and restore colour cast images
Authors: Liu Chang , Chen Xianqiao , Wu Yirong
Published: February 2019

This study proposes a new, simple but effective technique to detect and restore colour cast images, named modified grey world method. This method detects colour cast images of outdoor surveillance videos by computing the values in the YUV colour space, which makes it much easier than classic methods. Specific colour cast can be found out by calculating the hue values. Additionally, this method can detect not only simple colour cast images but also multiple colour cast images simultaneously. To detect and restore a colour cast image, the authors first remove all grey pixels and separate it into multiple parts with a maze‐solving algorithm. Then, they compute the YUV colour values of each part. If the values are too high or too low, this part of the input image is designated as a colour cast. Finally, they carry out a restoration procedure, in which they calculate weights by matching average colour value with a grey reference value in YUV colour space. This method has been tested in the Safety City surveillance system in Wuhan city, China. The results show that the proposed method leads to better results in detecting and restoring colour cast imaging than classic methods in outdoor surveillance videos.
Novel multispectral face descriptor using orthogonal walsh codes
Authors: Cevik Nazife , Cevik Taner , GurhanlI Ahmet
Published: February 2019

This paper proposes a novel high‐performance multispectral local descriptor that uses orthogonal Walsh codes during the generation of the discriminative feature set. Rotational variance and noise are compelling factors that significantly affect the distinctive performance of a facial identifier. The descriptor proposed in this article handles these challenges favourably sacrificing any distinctive performance. Orthogonal Walsh codes are used during the generation of the local descriptor. A Walsh code is assigned to each neighbour of a reference pixel. Before the assignment of an orthogonal code to each neighbouring pixel, these pixels are sorted in ascending order that consolidates the robustness of the method against rotational variances. Almost all methods proposed so far focus on grayscale images. However, colour bands contain important information about the relationship between pixels. Therefore, authors’ method considers RGB colour bands of pixels to improve distinctive performance. The results of extensive simulations show the remarkable and competitive performance of the proposed method regarding recognition accuracy and robustness against rotational variances as well as noise effects.
Modelling of a virtual power plant using hybrid automata
Authors: Javaid Chaudhry Jibran , Allahham Adib , Giaouris Damian , Blake Simon , Taylor Phil
Published: March 2019

Virtual power plant (VPP) is a hybrid power system with a mesh of distributed resources, local loads and storage with both discrete and continuous variables involved. Control of such system requires advanced control schemes to make distributed assets act together to mimic an actual power plant. Previously, to study the behaviour of such systems, complex algorithms and modelling tools have been used but this paper proposes the use of Hybrid Automata (HA) as a convenient tool to model these systems. To demonstrate this, HA is used to model a VPP for a research farm owned by Newcastle University as a first step to design the control for the system.
Quenching by gas compression and consumption
Authors: Man Allison W. S. , Lehnert Matthew D. , Vernet Joël D. R. , De Breuck Carlos , Falkendal Theresa
Published: February 2019

The objective of this work is to study how active galactic nuclei (AGN) influence star formation in host galaxies. We present a detailed investigation of the star-formation history and conditions of a z = 2.57 massive radio galaxy based on VLT/X-shooter and ALMA observations. The deep rest-frame ultraviolet spectrum contains photospheric absorption lines and wind features indicating the presence of OB-type stars. The most significantly detected photospheric features are used to characterize the recent star formation: neither instantaneous nor continuous star-formation history is consistent with the relative strength of the Si IIλ1485 and S Vλ1502 absorption. Rather, at least two bursts of star formation took place in the recent past, at 6+1-2 Myr and ≳20 Myr ago, respectively. We deduce a molecular H2 gas mass of (3.9 ± 1.0) × 1010 M⊙ based on ALMA observations of the [C I] 3P2−3P1 emission. The molecular gas mass is only 13% of its stellar mass. Combined with its high star-formation rate of (1020-170+190 M⊙ yr-1, this implies a high star-formation efficiency of (26 ± 8) Gyr−1 and a short depletion time of (38 ± 12) Myr. We attribute the efficient star formation to compressive gas motions in order to explain the modest velocity dispersions (⩽55 km s−1) of the photospheric lines and of the star-forming gas traced by [C I]. Because of the likely very young age of the radio source, our findings suggest that vigorous star formation consumes much of the gas and works in concert with the AGN to remove any residual molecular gas, and eventually quenching star formation in massive galaxies.
Exploring circumstellar effects on the lithium and calcium abundances in massive Galactic O-rich AGB stars
Authors: Pérez-Mesa V. , Zamora O. , García-Hernández D. A. , Osorio Y. , Masseron T. , Plez B. , Manchado A. , Karakas A. I. , Lugaro M.
Published: March 2019

Context. We previously explored the circumstellar effects on Rb and Zr abundances in a sample (21) of massive Galactic O-rich asymptotic giant branch (AGB) stars. Here we are interested in clarifying the role of the extended atmosphere in the case of Li and Ca. Li is an important indicator of hot bottom burning while the total Ca abundances in these stars could be affected by neutron captures.

Aims. We report new Li and Ca abundances in a larger sample (30) of massive Galactic O-rich AGB stars by using more-realistic extended model atmospheres. Li abundances had previously studied with hydrostatic models, while the Ca abundances have been determined here for the first time.

Methods. We used a modified version of the spectral synthesis code Turbospectrum and consider the presence of a gaseous circumstellar envelope and radial wind in the modelling of the spectra of these massive AGB stars. The Li and Ca abundances were obtained from the 6708 Å Li I and 6463 Å Ca I resonance lines, respectively. In addition, we studied the sensitivity of the pseudo-dynamical models to variations of the stellar and wind parameters.

Results. The Li abundances derived with the pseudo-dynamical models are very similar to those obtained from hydrostatic models (the average difference is 0.18 dex, σ2 = 0.02), with no difference for Ca. This indicates that the Li and Ca content in these stars is only slightly affected by the presence of a circumstellar envelope. We also found that the Li I and Ca I line profiles are not very sensitive to variations of the model wind parameters.

Conclusions. The new Li abundances confirm the Li-rich (and super Li-rich, in some cases) nature of the sample stars, supporting the activation of hot bottom burning in massive Galactic AGB stars. This is in good agreement with the theoretical predictions for solar metallicity AGB models from ATON, Monash, and NuGrid/MESA but is at odds with the FRUITY database, which predicts no hot bottom burning leading to the production of Li. Most (20) sample stars display nearly solar (within the estimated errors and considering possible non-local thermodynamic equilibrium effects) Ca abundances that are consistent with the available s-process nucleosynthesis models for solar metallicity massive AGB stars, which predict overproduction of 46Ca relatively to the other Ca isotope and the creation of the radioactive isotope 41Ca (half life of 0.1 Myr) but no change in the total Ca abundance. A minority (five) of the sample stars seem to show a significant Ca depletion (by up to 1.0 dex). Possible explanations are offered to explain their apparent and unexpected Ca depletion.
Ruprecht 147 DANCe
Authors: Olivares J. , Bouy H. , Sarro L. M. , Miret-Roig N. , Berihuete A. , Bertin E. , Barrado D. , Huélamo N. , Tamura M. , Allen L. , Beletsky Y. , Serre S. , Cuillandre J.-C.
Published: March 2019

Context. Ruprecht 147 is the oldest (2.5 Gyr) open cluster in the solar vicinity (< 300 pc), making it an important target for stellar evolution studies and exoplanet searches.

Aims. We aim to derive a census of members and the luminosity, mass, and spatial distributions of the cluster.

Methods. We used an astro-photometric data set including all available information from the literature together with our own observations. We processed the data with an updated version of an existent membership selection methodology.

Results. We identify 259 high-probability candidate members, including 58 previously unreported. All these candidates cover the luminosity interval between G ≳ 6 mag and i ≲ 21 mag. The cluster luminosity and mass distributions are derived with an unprecedented level of details allowing us to recognize, among other features, the Wielen dip. The mass distribution in the low-mass regime drops sharply at 0.4 M⊙ even though our data are sensitive to stellar masses down to 0.1 M⊙, suggesting that most very-low-mass members left the cluster as the result of its dynamical evolution. In addition, the cluster is highly elongated (ellipticity ∼0.5) towards the galactic plane, and mass segregated.

Conclusions. Our combined Gaia+DANCe data set allows us to obtain an extended list of cluster candidate members, and to derive luminosity, mass, and projected spatial distributions in the oldest open cluster of the solar vicinity.
Discovery of CO absorption at z = 0.05 in G0248+430
Authors: Combes F. , Gupta N. , Jozsa G. I. G. , Momjian E.
Published: March 2019

Absorption lines in front of distant quasars are quite rare in the millimeter domain. They can, however, bring very useful and complementary information to emission lines. We report here the detection with NOEMA of CO(1–0) and CN(1–0) lines in absorption, and the confirmation of CO emission in the quasar/galaxy pair Q0248+430/G0248+430. The system G0248+430 corresponds to two merging galaxies (a Seyfert and a LINER) at z = 0.0519 with a tidal tail just on the line of sight to the background quasar Q0248+430 at z = 1.313. Optical (CaII, NaI), H I 21 cm, and OH-1667 MHz absorption lines associated with the tidal tail of the foreground system have previously been detected toward the quasar, while four CO lines at different rotation J levels have been detected in emission from the foreground galaxies. New H I 21 cm line observations with the upgraded GMRT array are also presented. We discuss the molecular content of the merging galaxies, and the physical conditions in the absorbing interstellar medium of the tidal tail.
Interplanetary spread of solar energetic protons near a high-speed solar wind stream
Authors: Wijsen N. , Aran A. , Pomoell J. , Poedts S.
Published: February 2019

Aims. We study how a fast solar wind stream embedded in a slow solar wind influences the spread of solar energetic protons in interplanetary space. In particular, we aim at understanding how the particle intensity and anisotropy vary along interplanetary magnetic field (IMF) lines that encounter changing solar wind conditions such as the shock waves bounding a corotating interaction region (CIR). Moreover, we study how the intensities and anisotropies vary as a function of the longitudinal and latitudinal coordinate, and how the width of the particle intensities evolves with the heliographic radial distance. Furthermore, we study how cross-field diffusion may alter these spatial profiles.

Methods. To model the energetic protons, we used a recently developed particle transport code that computes particle distributions in the heliosphere by solving the focused transport equation (FTE) in a stochastic manner. The particles are propagated in a solar wind containing a CIR, which was generated by the heliospheric model, EUHFORIA. We study four cases in which we assume a delta injection of 4 MeV protons spread uniformly over different regions at the inner boundary of the model. These source regions have the same size and shape, yet are shifted in longitude from each other, and are therefore magnetically connected to different solar wind conditions.

Results. The intensity and anisotropy profiles along selected IMF lines vary strongly according to the different solar wind conditions encountered along the field line. The IMF lines crossing the shocks bounding the CIR show the formation of accelerated particle populations, with the reverse shock wave being a more efficient accelerator than the forward shock wave. The longitudinal intensity profiles near the CIR are highly asymmetric in contrast to the profiles obtained in a nominal solar wind. For the injection regions that do not cross the transition zone between the fast and slow solar wind, we observe a steep intensity drop of several orders of magnitude near the stream interface (SI) inside the CIR. Moreover, we demonstrate that the longitudinal width of the particle intensity distribution can increase, decrease, or remain constant with heliographic radial distance, reflecting the underlying IMF structure. Finally, we show how the deflection of the IMF at the shock waves and the compression of the IMF in the CIR deforms the three-dimensional shape of the particle distribution in such a way that the original shape of the injection profile is lost.
ADLs von Patienten nach Schlaganfall bewerten – Lucerne ICF-Based Multidisciplinary Observation Scale (LIMOS)
Authors: Ottiger Beatrice , Vanbellingen Tim
Published: March 2019

Die Neuroreha von Patienten nach Schlaganfall muss zielgerichtet und individuell sein. Ein Team am Luzerner Kantonsspital entwickelte deshalb LIMOS, eine Beobachtungsskala, mit der sich Aktivitäts- und Partizipationsfähigkeit von Patienten untersuchen und Therapieschwerpunkte ableiten lassen.
Head and Neck Manifestations of Granulomatosis with Polyangiitis: A Retrospective analysis of 19 Patients and Review of the Literature
Authors: Carnevale Claudio , Arancibia-Tagle Diego , Sarría-Echegaray Pedro , Til-Pérez Guillermo , Tomás-Barberán Manuel
Published: March 2019

Introduction Granulomatosis with Polyangiitis (GPA) is a small vessel vasculitis characterized by a necrositing granulomatous inflammation of the upper and lower respiratory tracts and focal/proliferative glomerulonephritis. In more than 70% of the cases, the presenting symptoms are head and neck manifestations that are often misdiagnosed as infectious or allergic in etiology.

Objective The present study provides an analysis of head and neck manifestations in a series of patients diagnosed with GPA. It also evaluates their medical and surgical treatment and provides a review of the relevant literature.

Methods A retrospective analysis of 19 patients diagnosed with GPA at a public tertiary care hospital between 2006 and 2017 was performed.

Results A total of 19 patients were included in the present study, and 16 of them presented head and neck manifestations. Sinonasal symptoms were the most common, affecting 56% of the patients, followed by laryngotracheal (31.25%) and ear (25%) symptoms. In 7 patients, sinonasal symptoms were the first manifestation of the disease (43.75%). Four patients underwent surgery at some stage of the disease.

Conclusions Head and neck involvement is common in GPA and may stand for the first or the only manifestation of the disease. The otolaryngologists play a central role in the diagnosis and long-term treatment of these patients, and they have to keep this pathology in mind when treating patients with ENT symptoms that do not respond as expected to the treatment.
Sound Localization Test in Presence of Noise (Sound Localization Test) in Adults without Hearing Alteration
Authors: Almeida Gleide Viviani Maciel , Ribas Angela , Calleros Jorge
Published: March 2019

Introduction Even people with normal hearing may have difficulties locating a sound source in unfavorable sound environments where competitive noise is intense.

Objective To develop, describe, validate and establish the normality curve of the sound localization test.

Method The sample consisted of 100 healthy subjects with normal hearing, > 18 years old, who agreed to participate in the study. The sound localization test was applied after the subjects underwent a tonal audiometry exam. For this purpose, a calibrated free field test environment was set up. Then, 30 random pure tones were presented in 2 speakers placed at 45° (on the right and on the left sides of the subject), and the noise was presented from a 3rd speaker, placed at 180°. The noise was presented in 3 hearing situations: optimal listening condition (no noise), noise in relation to 0 dB, and noise in relation to - 10 dB. The subject was asked to point out the side where the pure tone was being perceived, even in the presence of noise.

Results All of the 100 participants performed the test in an average time of 99 seconds. The average score was 21, the medium score was 23, and the standard deviation was 3.05.

Conclusion The sound localization test proved to be easy to set-up and to apply. The results obtained in the validation of the test suggest that individuals with normal hearing should locate 70% of the presented stimuli. The test can constitute an important instrument in the measurement of noise interference in the ability to locate the sound.
Intraoperative Anesthesiology Management and Patient Outcomes for Surgical Revascularization for Moyamoya Disease: A Review and Clinical Experience
Authors: Williams George , Jones William , Chaudhry Rabail , Cai Chunyan , Pednekar Greesha , Long Alia , Chouhan Shilpa , Artime Carlos , Wegner Robert , Grewal Navneet , Patterson Velvet , Contreras Daniel , Ferrario Lara
Published: March 2019

Background Moyamoya disease (MMD) is a rare cerebrovascular condition, often presenting as a headache or stroke in adults. Anesthetic management of this illness may challenge providers because it can affect the long-term neurologic outcome and hospital length of stay (LOS) in patients with MMD.

Materials and Methods A literature search was conducted to assess etiology and epidemiology, as well as existing reports of intraoperative management of MMD. Due to sparse findings, the search was expanded to include studies of the use of intraoperative anesthetic agents during other neurosurgical procedures. We also retrospectively reviewed all MMD cases from January 1, 2009, to December 31, 2015, at Memorial Hermann Hospital-Texas Medical Center, where intraoperative management involved craniotomy and surgical revascularization. Data were collected primarily on the use of several anesthetic agents. The LOS and any adverse events were also recorded for each case. The data were divided into two equivalent case cohorts: (1) January 1, 2009, to February 18, 2013, and (2) February 19, 2013, to December 31, 2015.

Results Remifentanil use notably increased between the first and second time periods while fentanyl use decreased. Desflurane usage also demonstrated an observed increase when our two cohorts were compared. Additionally, there was a decrease in the mean LOS between the first and second periods of 3.9 and 3.3 days, respectively.

Conclusion Increasing use of remifentanil in MMD cases could be attributed to its ability to provide more stable hemodynamics during induction, maintenance, and emergence of anesthesia when compared with fentanyl. Lower systolic pressures, diastolic pressures, and heart rates were reported in patients receiving remifentanil over fentanyl.
Abordaje de Smith Petersen modificado para fracturas de cuello femoral Pauwels III – Garden IV
Authors: Villalón Ignácio , Contesse Iván , Vigueras Cristóbal , del Río Javier , Piriz Julio , Riera José
Published: March 2019

El abordaje de Smith Petersen modificado (SPM), permite la reducción de fracturas del cuello femoral desde anterior, manteniendo la fijación a través de un abordaje lateral. Realizar la reducción bajo visión directa mejoraría la calidad de la reducción y los resultados en fracturas complejas de cuello femoral.

Métodos Estudio retrospectivo de ocho pacientes con fracturas de cuello femoral Pauwels III/Garden IV secundarias a un accidente de alta energía operadas con abordaje SPM. Registramos el tiempo de evolución desde el accidente hasta la cirugía. Se realizó radiografía y tomografía axial computada postoperatoria. Seguimos los pacientes con radiografías mensuales hasta evidenciar consolidación de la fractura y casos de necrosis avascular.

Resultados En promedio, los pacientes fueron operados 2,1 días tras el accidente y fueron seguidos con una mediana de 24,5 meses tras su cirugía. Siete de los ocho pacientes consolidaron. Sólo un caso presentó una no-unión que requirió de una prótesis total de cadera. No hubo casos de necrosis avascular.

Conclusión Las fracturas de cuello femoral de alta energía en pacientes jóvenes son lesiones poco frecuentes. Aunque esta serie es pequeña, llama la atención que tratándose de lesiones desplazadas y con rasgos verticales no observamos casos de necrosis avascular, a pesar de algunos casos con prolongado tiempo de evolución desde el accidente hasta la cirugía. Creemos que esas fracturas deben operarse lo antes posible, pero que es más importante lograr una reducción anatómica en vez de retrasar algunas horas la cirugía. En nuestra experiencia, el abordaje de SPM facilita la reducción adecuada en fracturas complejas de cuello femoral.
Translabyrinthine Approach for Resection of Vestibular Schwannoma
Authors: Feng Yening , Patel Neil S. , Gompel Jamie J. Van , Carlson Matthew L.
Published: March 2019

Objectives This video describes the surgical indications, relevant anatomy, and surgical steps of routine translabyrinthine surgery for gross total resection of sporadic vestibular schwannoma.

Design The procedure is presented through a surgical instructional video.

Setting The surgery took place at tertiary skull base referral center.

Parcipant A 47-year-old patient reported with nonserviceable hearing, frequent episodes of vertigo, recurrent severe headache, and a small unilateral right sided vestibular schwannoma.

Results Gross total resection with preservation of facial nerve function was achieved.

Conclusion This instructional video documents the surgical steps and relevant anatomy for translabyrinthine resection of vestibular schwannoma.

The link to the video can be found at: https://youtu.be/CJ2vKMLs7aI.
Robotics in Total Knee Arthroplasty
Authors: Bautista Maria , Manrique Jorge , Hozack William J.
Published: March 2019

Total knee arthroplasty (TKA) is a highly successful operation that improves patients' quality of life and functionality. Yet, up to 20% of TKA patients remain unsatisfied with their clinical result. Robotic TKA has gained increased attention and popularity as a means of improving patient satisfaction. The promise of robotic-assisted TKA is that it provides a surgeon with a tool that accurately executes bone cuts according to presurgical planning, as well as provides the surgeon with intraoperative feedback helpful for restoring knee kinematics and soft tissue balance. Several systems are now available, each with their own advantages and disadvantages. Evidence that the use of robotics will lead to improved implant survival, function, and patient-reported outcomes is slowly being accumulated, but this has not been clearly proven to date. Recent literature does show that the use of robotics during TKA is not associated with increased surgical time or complications. The goal of this review is to provide an objective assessment of the evidence surrounding robotic technology for TKA.
Notes on the Accessory Flexor Carpi Ulnaris Muscle: A Rare Supernumerary Variation
Authors: Pires Lucas Alves Sarmento , Machado Graciele de Caro Reis , Fernandes Rodrigo Mota Pacheco , Manaia Jorge Henrique Martins , Champs João Francisco Silva , Babinski Marcio Antonio
Published: March 2019

Variations of the forearm muscles are well described in the literature. In spite of that, reports regarding the accessory flexor carpi ulnaris muscle are scarce due to its rarity. This muscle usually originates from the medial epicondyle of the humerus with the flexor muscle mass and inserts itself into the palmar aponeurosis or the pisiform bone together with the flexor carpi ulnaris muscle. Supernumerary and anomalous muscles of the anterior compartment of the forearm have been associated with ulnar nerve and artery compression. Furthermore, they may also mimic neuromas and soft tissue tumors. The study of supernumerary muscles is necessary, as they may be an option to tendon grafts and muscle flaps. The aim of this paper is to describe the presence of the accessory flexor carpi ulnaris muscle on the left forearm of a cadaver fixated in a phenol solution and discuss its clinical and anthropological significance.
Recurrence relations of the multi-indexed orthogonal polynomials V: Racah and
q
-Racah types
Authors: Odake Satoru
Published: February 2019

In previous papers, we discussed the recurrence relations of the multi-indexed orthogonal polynomials of the Laguerre, Jacobi, Wilson, and Askey-Wilson types. In this paper, we explore those of the Racah and q-Racah types. For the M-indexed (q-)Racah polynomials, we derive 3 + 2M term recurrence relations with variable dependent coefficients and 1 + 2L term (L ≥ M + 1) recurrence relations with constant coefficients. Based on the latter, the generalized closure relations and the creation and annihilation operators of the quantum mechanical systems described by the multi-indexed (q-)Racah polynomials are obtained. In Appendix B and Appendix C, we present a proof and some data of the recurrence relations with constant coefficients for the multi-indexed Wilson and Askey-Wilson polynomials.
Strain-driven thermodynamic stability and electronic transitions in ZnX (X = O, S, Se, and Te) monolayers
Authors: Chaurasiya Rajneesh , Dixit Ambesh , Pandey Ravindra
Published: February 2019

Semiconducting Zn chalcogenide monolayers are important members of the 2D family of materials due to their unique electronic properties. In this paper, we focus on strain-modulated electronic properties of monolayers of ZnX, with X being O, S, Se, and Te. ZnO and ZnS monolayers have a hexagonal graphene-like planar structure, while ZnSe and ZnTe monolayers exhibit slightly buckled silicene and germanene-like structures, respectively. Density functional theory calculations find the hexagonal ZnO monolayer to be dynamically stable. However, ZnS, ZnSe, and ZnTe monolayers are predicted to be less stable with small imaginary frequencies. The application of tensile strain to these monolayers, interestingly, yields stability of dynamically less stable structures together with the modification in the nature of the bandgap from direct to indirect. For a tensile strain of about 8%, a closure of the bandgap in ZnTe is predicted with the semiconductor-metal transition. The results, therefore, find strain-induced stability and modification in electronic properties of monolayers of Zn chalcogenides, suggesting the use of these monolayers for novel device applications.
Representation of surfaces using spinor operators
Authors: Vaz Jayme
Published: March 2019

We use the concept of spinor operator to study some aspects of the classical theory of surfaces in three dimensions. We show that a spinor operator representing a surface satisfies a pair of Dirac-like equations and that this spinor operator representation is a generalization of the Weierstrass representation of minimal surfaces. We also obtain spinor operator representations of a surface directly from its parameterization in terms of isothermal parameters, without the need of solving the pair of Dirac-like equations. We apply these results to minimal surfaces and their deformations and also show how they can be written in terms of quaternions and complex numbers.
Noise induced escape in one-population and two-population stochastic neural networks with internal states
Authors: Li Yang , Liu Xianbin
Published: February 2019

In the present paper, the escapes from the basins of fixed points induced by intrinsic noise are investigated in both one- and two-population stochastic hybrid neural networks. In the weak noise limit, the quasipotentials are computed through the application of WKB approximation to the original hybrid system and the results of quasi-steady-state (QSS) diffusion approximation. It is seen that the two results are consistent with each other within the neighborhood of a fixed point and an obvious discrepancy arises in the other area, of which the reason is then explored and revealed. Furthermore, the relationship between the fluctuational paths and the relaxational ones is analyzed, based on which some specific results for the hybrid system is obtained. Besides, for the two-population model, the phenomenon of saddle point avoidance is investigated by using both theoretical and numerical methods. Finally, the topological structure of Lagrangian manifold is analyzed, and its particular features and something analogous to the stochastic differential equation are found according to the accuracy of QSS within the vicinity of the saddle point.
A parameter estimation method using linear response statistics: Numerical scheme
Authors: Zhang He , Li Xiantao , Harlim John
Published: March 2019

This paper presents a numerical method to implement the parameter estimation method using response statistics that was recently formulated by the authors. The proposed approach formulates the parameter estimation problem of Itô drift diffusions as a nonlinear least-squares problem. To avoid solving the model repeatedly when using an iterative scheme in solving the resulting least-squares problems, a polynomial surrogate model is employed on appropriate response statistics with smooth dependence on the parameters. The existence of minimizers of the approximate polynomial least-squares problems that converge to the solution of the true least square problem is established under appropriate regularity assumption of the essential statistics as functions of parameters. Numerical implementation of the proposed method is conducted on two prototypical examples that belong to classes of models with a wide range of applications, including the Langevin dynamics and the stochastically forced gradient flows. Several important practical issues, such as the selection of the appropriate response operator to ensure the identifiability of the parameters and the reduction of the parameter space, are discussed. From the numerical experiments, it is found that the proposed approach is superior compared to the conventional approach that uses equilibrium statistics to determine the parameters.
Molecular dynamics simulations of crystal nucleation in entangled polymer melts under start-up shear conditions
Authors: Anwar Muhammad , Graham Richard S.
Published: February 2019

Understanding the flow induced crystallisation process is necessary due to its technological relevance to polymer processing. Polymer crystallisation controls the morphology of semi-crystalline polymers and hence the properties of the end product. We perform molecular dynamics simulations of polymer melts consisting of sufficiently entangled linear chains under shear flow. We determine the Rouse relaxation time (τR) for linear polymer chains using an established rheological model at different temperatures and fit the simulation data with the Arrhenius and Williams-Landel-Ferry equations. We simulate the crystallisation induction times for different values of the Rouse–Weissenberg number (WiR=γ̇τR) at different temperatures. We observe that the level of strain and stretch required to induce crystallisation increases with temperature. We find that the induction times follow a power law in shear rate and observe a more pronounced effect of flow rate for higher temperatures than at lower temperatures. Moreover, we determine that nucleation events occur relatively early in the shear transient and at a stretch value that is smaller than its steady state value. We also report the values of strain at which the occurrence of a nucleation event is most likely to happen.
Interface resonance in Fe/Pt/MgO multilayer structure with large voltage controlled magnetic anisotropy change
Authors: Jibiki Y. , Goto M. , Tsujikawa M. , Risius P. , Hasebe S. , Xu X. , Nawaoka K. , Ohkubo T. , Hono K. , Shirai M. , Miwa S. , Suzuki Y.
Published: March 2019

Electric control of magnetism has been a topic of interest for various spintronic applications. It is known that monoatomic Pt layer insertion at the Fe/MgO interface increases voltage-controlled magnetic anisotropy (VCMA). However, the reason for the optimality of this thickness has not been explained thus far. In this study, we observed the changes in the electronic states at the Fe/MgO interface using tunneling spectroscopy on an epitaxial Fe(001)/Pt/MgO(001) structure to characterize the density of states around the Fermi level. We found that a surface resonant state is formed at the Fermi level by the insertion of a monoatomic Pt layer, which is consistent with our first principles study. In addition, the VCMA enhancement owing to the formation of this surface resonance state agrees with the recently proposed microscopic theory.
All-carbon devices based on sp2-on-sp3 configuration
Authors: Yuan Qilong , Lin Cheng-Te , Chee Kuan W. A.
Published: March 2019

Carbon has around 500 allotropes, and most of them have excellent physical properties offering great potential for the development of electronic, optoelectronic, energy storage, and sensor applications. In the case of diamond and graphene/graphite, although the carbon atoms have different hybridization structures, their complementary characteristics and potential for direct conversion between them may open up opportunities for novel all-carbon device applications. Diamond and graphene/graphite have unique superior properties and good lattice matching between them so that the direct fabrication of high-quality graphene-on-diamond heterostructures enables the new development of a variety of ultrawide bandgap devices and chemical/bio-sensors. In this perspective, we introduce recent investigations into the formation of graphene films on diamond substrates through an in situ sp3-to-sp2 conversion process to enable their application to radiation detection/photo-electronics, high-power/high-frequency electronics, and chemical/biological sensing.
Identification of slow relaxation modes in a protein trimer via positive definite relaxation mode analysis
Authors: Karasawa Naoyuki , Mitsutake Ayori , Takano Hiroshi
Published: February 2019

Recently, dynamic analysis methods in signal processing have been applied to the analysis of molecular dynamics (MD) trajectories of biopolymers. In the context of a relaxation mode analysis (RMA) method, based on statistical physics, it is explained why the signal-processing methods work well for the simulation trajectories of biopolymers. A distinctive difference between the RMA method and the signal-processing methods is the introduction of an additional parameter, called an evolution time parameter. This parameter enables us to better estimate the relaxation modes and rates, although it increases computational difficulty. In this paper, we propose a simple and effective extension of the RMA method, which is referred to as the positive definite RMA method, to introduce the evolution time parameter robustly. In this method, an eigenvalue problem for the time correlation matrix of physical quantities relevant to slow relaxation in a system is first solved to find the subspace in which the matrix is numerically positive definite. Then, we implement the RMA method in the subspace. We apply the method to the analysis of a 3-μs MD trajectory of a heterotrimer of an erythropoietin protein and two of its receptor proteins, and we demonstrate the effectiveness of the method.
Analytical calculation of the translational velocity of linked vortices
Authors: Gonzalez Jeasson F. , Munévar E.
Published: March 2019

This paper determines analytically the velocity field induced by a configuration of linked vortices, with the aim of finding the translational velocity of such a configuration. The linked-vortex configuration consists of two vortices; the vortices are thin tubes of circular cross section lying on the surface of an immaterial torus of small aspect ratio r1r0 (where r1 is the cross section radius of a torus and r0 is its centerline radius). The induced velocity field has been found based on the vector potential associated with the Biot-Savart law by using a multipolar expansion; the comparison of this field with the material condition on the surface of the vortices allows one to calculate the translational velocity. The solution obtained retains effects to first order at the multipolar expansion, which corresponds to the effects the vortex curvature has at the vorticity distribution on its cross section. This solution agrees with the numerical results in the range of 2%. The method presented is generalized to the case of n linked vortices.
Benchmarking the performance of approximate van der Waals methods for the structural and energetic properties of SiO2 and AlPO4 frameworks
Authors: Fischer Michael , Kim Won June , Badawi Michael , Lebègue Sébastien
Published: March 2019

Density functional theory (DFT) calculations using sixteen different approaches, fourteen of which were designed to include dispersion interactions [DFT + D and van der Waals (vdW)-DF methods], were performed for a set of sixteen framework compounds with either SiO2 or AlPO4 composition. The compounds include four dense structures (α-quartz, α-cristobalite, and their AlPO4 analogues), eight all-silica zeolites, and four aluminophosphate zeotypes (AlPOs). We analyzed the performance in reproducing the equilibrium structure for all systems, and computed bulk moduli and relative stabilities were compared to experiments for those compounds where experimental data are available. We found that the results obtained with functionals that take into account dispersive interactions are closer to experiments than those obtained with a bare generalized gradient functional. However, the variation among individual methods is considerable, and functionals that perform well for one quantity may give rather large deviations for another. Taking together the whole body of results, it appears that the Perdew-Burke-Ernzerhof functional including a many-body dispersion correction and the rev-vdW-DF2 methods present the best performance for the description of SiO2 and AlPO4 materials.
Time-resolved x-ray crystallography capture of a slow reaction tetrahydrofolate intermediate
Authors: Cao Hongnan , Skolnick Jeffrey
Published: March 2019

Time-resolved crystallography is a powerful technique to elucidate molecular mechanisms at both spatial (angstroms) and temporal (picoseconds to seconds) resolutions. We recently discovered an unusually slow reaction at room temperature that occurs on the order of days: the in crystalline reverse oxidative decay of the chemically labile (6S)-5,6,7,8-tetrahydrofolate in complex with its producing enzyme Escherichia coli dihydrofolate reductase. Here, we report the critical analysis of a representative dataset at an intermediate reaction time point. A quinonoid-like intermediate state lying between tetrahydrofolate and dihydrofolate features a near coplanar geometry of the bicyclic pterin moiety, and a tetrahedral sp3 C6 geometry is proposed based on the apparent mFo-DFc omit electron densities of the ligand. The presence of this intermediate is strongly supported by Bayesian difference refinement. Isomorphous Fo-Fo difference map and multi-state refinement analyses suggest the presence of end-state ligand populations as well, although the putative intermediate state is likely the most populated. A similar quinonoid intermediate previously proposed to transiently exist during the oxidation of tetrahydrofolate was confirmed by polarography and UV-vis spectroscopy to be relatively stable in the oxidation of its close analog tetrahydropterin. We postulate that the constraints on the ligand imposed by the interactions with the protein environment might be the origin of the slow reaction observed by time-resolved crystallography.
Fog collection on a superhydrophilic wire
Authors: Jiang Youhua , Savarirayan Shaan , Yao Yuehan , Park Kyoo-Chul
Published: February 2019

Fog collection shows great promise as a solution to the water scarcity problem in some arid regions. In addition, it can be applied to saving water required for important industrial system processes, such as recapturing water in cooling towers of thermal power plants. Although a number of studies have been conducted to investigate the principles of fog collection, most of the studies have sought methods to facilitate the transport of the captured liquid on multiple wire systems. However, it is important to study the fundamental correlation between the fog collection rate and the process of fog droplet capture, which has been largely underexplored, in order to understand the full span of the fog collection process and improve its collection efficiency. In this study, we aim to examine the correlation between the measured collection rate and the deposition step of fog collection on a wire, using spontaneous wetting of vertical, superhydrophilic wires that minimize the liquid loss during transport to precisely measure the volume of collected water. Experiments were conducted using the wires with various diameters under different wind speed conditions. The results show that the measured fog collection rate per unit area is linearly proportional to an empirically obtained deposition efficiency of aerosols, a function of the Stokes number. In addition to the controlled liquid transport by the modification of surface wettability, this study provides physical insights for the optimal design of fog collectors from an aerodynamics-centered perspective, benefitting the fight against the global water crisis.
Application of transient CHI plasma startup to future ST and AT devices
Authors: Hammond K. C. , Raman R. , Jardin S. C.
Published: March 2019

Employment of non-inductive plasma start-up techniques would considerably simplify the design of a spherical tokamak fusion reactor. Transient coaxial helicity injection (CHI) is a promising method, expected to scale favorably to next-step reactors. However, the implications of reactor-relevant parameters on the initial breakdown phase for CHI have not yet been considered. Here, we evaluate CHI breakdown in reactor-like configurations using an extension of the Townsend avalanche theory. We find that a CHI electrode concept in which the outer vessel wall is biased to achieve breakdown, while previously successful on NSTX and HIT-II, may exhibit a severe weakness when scaled up to a reactor. On the other hand, concepts which employ localized biasing electrodes such as those used in QUEST would avoid this issue. Assuming that breakdown can be successfully attained, we then apply scaling relationships to predict plasma parameters attainable in the transient CHI discharge. Assuming the use of 1 Wb of injector flux, we find that plasma currents of 1 MA should be achievable. Furthermore, these plasmas are expected to Ohmically self-heat with more than 1 MW of power as they decay, facilitating efficient hand-off to steady-state heating sources. These optimistic scalings are supported by Tokamak Simulation Code simulations.
A systems perspective of quantum computing
Authors: Matsuura Anne , Johri Sonika , Hogaboam Justin
Published: March 2019

Quantum architects, with knowledge of both physics and computer engineering, are key to developing scalable quantum computers.