bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulating the molecular configuration by varying linking bridge for double-anchored dye-sensitized solar cells
Authors: Cai Ke , Hua Tao , Wu Hanlun , Wang Lingyun , Tang Hao , Cao Derong
Published: June 2020

Three novel metal-free organic dyes (TPTZ1, TPTZ2, and TPTZ3) with an A–D–π–D–A configuration were synthesized and applied for dye-sensitized solar cells (DSSCs). The relationship between the photovoltaic properties and the different connection bridges of these organic dyes was studied systematically, showing that a strategical variation on the linkage ways of dithiophene can obviously affect the twisted degree of backbone and, thus, have a great effect on inhibiting the intermolecular aggregation. Compared with a bulky rigid group substituted on TPTZ3, introducing flexible side chains at suitable sites on the TPTZ1 and TPTZ2 seems to be a more effective strategy to achieve high photoelectric performance for double anchoring dye. Indeed, the DSSCs based on TPTZ2 exhibit a high efficiency of 7.50%, reaching 99% of an N719-based standard cell at the same condition. This study provides a new approach for highly efficient anti-aggregation organic sensitizers.
WO3/ZnO nanowire heterojunction as hole transport channel for building up persistent holographic fringes
Authors: Li Ning , Fu Shencheng , Wu Jiarui , Li Xin , Zhou Jiahui , Wang Yiqian , Zhang Xintong , Liu Yichun
Published: June 2020

Transition metal oxides exhibit an excellent photochromic property, which can be applied in optical information storage. However, the decolorization reaction hinders the formation of optical bi-stable states of the oxides. Here, we deposit WO3 nanoparticles into ZnO nanowire arrays to form a multi-site heterojunction. The heterojunction micro-interface acts as a spatially dispersed hole transport channel to suppress the WO3 carrier recombination and to prolong the relaxation time more than 104 s. The photochromic response range covers the whole visible-NIR regions, and the absorption modulation amplitude is improved significantly. Persistent holographic fringes with alternated arrangement of WO3 and HxWO3 show a diffraction efficiency reaching 1.1% even at a very low writing power. This work is expected to be one of the most pursued application strategies for the integration of storage and the display of high-density information.
Electrostatic control of dewetting dynamics
Authors: Edwards Andrew M. J. , Ledesma-Aguilar Rodrigo , Newton Michael I. , Brown Carl V. , McHale Glen
Published: June 2020

The stability of liquid films on surfaces is critically important in microscale patterning and the semiconductor industry. If the film is sufficiently thin, it may spontaneously dewet from the surface. The timescale and rate of dewetting depend on the film repellency of the surface and the properties of the liquid. Therefore, control over the repellency requires modifying surface chemistry and liquid properties to obtain the desired rate of film retraction. Here, we report how the dynamics of a receding thin liquid stripe to a spherical cap droplet can be controlled by programming surface repellency through a non-contact electrostatic method. We observe excellent agreement between the expected scaling of the dynamics for a wide range of voltage-selected final contact angles. Our results provide a method of controlling the dynamics of dewetting with high precision and locality relevant to printing and directed templating.
Absence of piezoelectric enhancement around the morphotropic phase boundaries for Bi1−xNdxFeO3 ceramics
Authors: Chen P. Z. , Li Y. Q. , Li X. , Zheng S. H. , Liu M. F. , Lin L. , Yan Z. B. , Jiang X. P. , Liu J.-M.
Published: June 2020

BiFeO3 has been receiving continuous attention for its excellent ferroelectric and multiferroic properties. Nevertheless, the piezoelectricity as a complementary property of ferroelectricity remains less addressed for BiFeO3 at least in a single phase form. In this work, we investigate the piezoelectric behaviors of bulk Bi1−xNdxFeO3 ceramics, given that the Nd-substitution may trigger structural phase transitions from the R3c phase to the Pna21 phase and eventually toward the non-polar Pnma phase. It is revealed that the piezoelectric coefficient d33 does increase with the increasing Nd content x inside the R3c phase region. However, no d33-enhancement across the R3c–Pna21 boundary region and the Pna21–Pnma boundary region is identified, suggesting no positive correlation between the piezoelectric coefficient and the possible morphotropic phase boundaries. The observed d33-enhancement inside the R3c phase region should be attributed to the remarkably reduced domain size and release of pinned domain wall motion by defects.
Enhancement of perovskite photoluminescence characterizations by using lithography-free metal nanostructures
Authors: Fang Rongpeng , Lin Yu-Sheng
Published: June 2020

To date, organic–inorganic metal halide perovskite material has become an emerging research topic for scientists to alternate the semiconductor material in the optoelectronic applications. However, the photoluminescence (PL) efficiency of perovskite material is quite low, which impacts the performance of perovskite-based optoelectronic devices. Here, we propose and demonstrate an effective approach to enhance the PL efficiency of perovskite material. We utilize the metal nanostructures fabricated on the perovskite surface. Metal nanostructures possess extraordinary electromagnetic properties, e.g., easily controlled the amplitude, phase, and polarization of the incident light, which can be utilized to enhance the PL performance of the perovskite material. The intensity and spectral bandwidth of the PL spectrum could be enhanced significantly via metal nanostructures. The full width at half maximum of PL spectral bandwidth could be narrowed to several nanometers. This nanostructure-enhanced PL characterization of the perovskite material exhibits better monochromaticity and provides the simple, cost-effective, and potentially scalable method for the development of high-efficiency light emitting diodes, solar cells, photodetectors, etc.
Numerical simulations of unsteady flows in a rotating channel using a novel eigenfunction expansion method
Authors: Rubbab Q. , Mahsud Y. , Irshad S. , Imran M. A. , Ahmadian A. , Salahshour S. , Ferrara M.
Published: June 2020

Starting flows of a viscous incompressible fluid, modeled by the time-fractional derivatives, within a rotating channel due to an impulsive pressure gradient are studied. Using the eigenfunction expansion, the analytic solutions in series form are obtained. The flow of the ordinary fluid is studied as a special case of the time-fractional problem. The convergence of series solutions is proved. In addition, using the classical analytical method, coupled with the Laplace transform and Stehfest’s algorithm, an approximate solution is found. The flow rates in x- and y-directions are determined. In the case of the ordinary fluid, the steady-state and transient components of velocities are obtained. The numerical calculations are carried out by using the Mathcad software. It is found that, for fractional fluids, the reversal flow is much attenuated if the values of the fractional parameter are less than 1.
Bound states and symmetry breaking of the ring C20− anion
Authors: Yang Yi-Fan , Cederbaum Lorenz S.
Published: June 2020

Determining the geometry of carbon rings is an ongoing challenge. Based on our calculations at a state-of-the-art level, we found that the C20− ring possesses five bound electronic states, including a superatomic state, which is the first superatomic state found for a ring. The nature of these electronic states is discussed. Our calculation reveals a symmetry breaking of the C20− ring anion ground electronic structure occurring upon attaching an electron to the neutral ring. The discussion of the possible symmetry breaking mechanisms indicates that the shrinking and distortion of the ring upon electron attachment, leading to the symmetry breaking, is a result of the interplay between the symmetry breaking and the totally symmetric modes. The discussion enriches the palette of possible symmetry breaking phenomena in carbon clusters.
Semiclassical instanton formulation of Marcus–Levich–Jortner theory
Authors: Heller Eric R. , Richardson Jeremy O.
Published: June 2020

Marcus–Levich–Jortner (MLJ) theory is one of the most commonly used methods for including nuclear quantum effects in the calculation of electron-transfer rates and for interpreting experimental data. It divides the molecular problem into a subsystem treated quantum-mechanically by Fermi’s golden rule and a solvent bath treated by classical Marcus theory. As an extension of this idea, we here present a “reduced” semiclassical instanton theory, which is a multiscale method for simulating quantum tunneling of the subsystem in molecular detail in the presence of a harmonic bath. We demonstrate that instanton theory is typically significantly more accurate than the cumulant expansion or the semiclassical Franck–Condon sum, which can give orders-of-magnitude errors and, in general, do not obey detailed balance. As opposed to MLJ theory, which is based on wavefunctions, instanton theory is based on path integrals and thus does not require solutions of the Schrödinger equation nor even global knowledge of the ground- and excited-state potentials within the subsystem. It can thus be efficiently applied to complex, anharmonic multidimensional subsystems without making further approximations. In addition to predicting accurate rates, instanton theory gives a high level of insight into the reaction mechanism by locating the dominant tunneling pathway as well as providing similar information to MLJ theory on the bath activation energy and the vibrational excitation energies of the subsystem states involved in the reaction.
Are the Central Flores languages really typologically unusual?
Authors: Elias Alexander
Published: June 2020

The languages of Central Flores (Austronesian) are typologically
distinct from their nearby relatives. They have elaborate numeral classifier systems, quinary numeral systems, and lack all bound morphology. McWhorter (2019) proposes that their isolating typology is due to
imperfect language acquisition of a Sulawesi language, brought to Flores by settlers
from Sulawesi in the relatively recent past. I propose an alternative interpretation,
which better accounts for the other typological features found in Central Flores: the
Central Flores languages are isolating because they have a strong substrate influence
from a now-extinct isolating language which belonged to the Mekong-Mamberamo linguistic
area (Gil 2015). This explanation better
accounts for the typological profile of Central Flores and is a more plausible contact
scenario.
From Lamaholot to Alorese
Authors: Klamer Marian A.F.
Published: June 2020

Alorese is a prime example of a morphologically isolating language.
This paper traces the process of morphological simplification it has undergone by
addressing the following questions: (i) What was the morphological profile of its
ancestor, pre-Alorese? (ii) When did Alorese start to lose its morphology? (iii) Which
factors caused this loss? By comparing the morphological profile of current Alorese with
its sister language, Lewoingu-Lamaholot, I conclude that the morphology of pre-Alorese
was at least as complex as current Lewoingu-Lamaholot. Pre-Alorese underwent a process
of drastic and swift morphological loss after its speakers migrated to Pantar island
around 1300 AD. Pre-Alorese must have had a significant proportion of adult second
language speakers who acquired it imperfectly, thus causing its morphology to be lost.
Thus, this is a good example of morphological simplification due to imperfect adult
learning in a small-scale language variety.
Double agent, double cross?
Authors: Williams-van Klinken Catharina , Hajek John
Published: June 2020

In East Timor, there have been centuries of contact between the
strongly isolating Austronesian language Tetun Dili and the morphologically-rich Romance
language Portuguese. In all this time, only one derivational morpheme has been borrowed
into Tetun Dili for use with native lexicon. This is -dor, a
transparent agentive suffix which neatly fits the word order and stress patterns of
existing Tetun Dili agentive compounds. Tetun Dili has borrowed numerous nouns with this
suffix. However when in combination with native roots, it has shifted in terms of its
semantics, word class of the root and derivation, and even word status, bringing it more
in line with pre-existing native agentive morphemes. In other words, Tetun’s strongly
isolating nature has won, at least for now.
Relativistic kinematics of two-particle scattering reactions with participation of tachyons
Authors: Samsonenko N V , Semin M V
Published: June 2020

The paper discusses limitations resulting from the laws of conservation of energy and momentum in the processes of elastic and quasi-elastic scattering of relativistic particles with the participation of tachyons, luxons, and bradyons. The obtained expressions for the particle energies are given in the center-of-mass system in the generally accepted Mandelstam variables. Using the laws of conservation of energy and momentum, several channels of reactions of ultrarelativistic particles of high energy in cosmic rays have been considered. It has been shown that on the basis of the expressions obtained, assuming the existence of particles with imaginary masses — tachyons, the effect of “red shift” can be explained.
Influence of the magnetic interactions on the mass spectrum of elementary particles
Authors: Samsonenko N V , Ndahayo F , Alibin M A
Published: June 2020

Different approaches to the problem of mass quantization are discussed. The Barut ideas of crucial influence of magnetic forces for explaining the properties of the strong interaction are considered in details. It is shown that this approach gives the possibility to understand the enormous number of elementary particles (about 400) as the excited states of stable fundamental particles (e, p, v), bounded by magnetic interactions.
The lattice Hamiltonian modeling for active nematic liquid crystals with disclinations and oriented surfaces
Authors: Elnikova L V , Belyaev V V
Published: June 2020

We study the system of colloid active nematic liquid crystals evolving with transformation of the structure of surface linear topological defects. We estimate numerically the SO(2) Hamiltonian of the BKT model for disclinations on the surfaces connected with flows, which can participate in the defect ordering transitions.
Universal central extensions of superalgebras with bracket
Authors: Pinchuk I A
Published: June 2020

Superalgebras and, in particular, Lie superalgebras and Poisson superalgebras play an important role in theoretical physics. For example, one of the applications of such algebras is in supersymmetric unified field theories for describing bosons and fermions. In this regard, any research in the theory of superalgebras turns out to be significant from the point of view of theoretical physics. The article discusses some generalizations of Poisson superalgebras, namely, a superalgebra with a bracket. For these superalgebras, a universal central extension is constructed and the kernel of such an extension as the second homology group of the superalgebra with coefficients in the trivial module is calculated.
Transfer of water molecules in presence of low density water vapor
Authors: Konyukhov V K , Valentinova N I
Published: June 2020

Problems of molecular transfer in gas environment are considered with assumption that part of water molecules may change their properties to provide transfer process. This change consists in increase of dimension of vector space, which used to describe transfer process, from 3 to 4. Other cases of extending of dimension of vector space are particular considered. At first, relations between affine group and Markov chain is considered. An action of Markov chain matrix as affine matrix is analyzed with result that point with coordinate number equal 1 is fixed point on straight line.
The hydrothermal synthesis and RTA conditions influence on the Y2O3:Eu nanosized phosphors microstructure
Authors: Vlasenko A B , Bakhmetyev V V , Khristyuk N A
Published: June 2020

When developing new methods for the diagnosis and treatment of cancer, the use of nanomaterials may be promising. One of the ways to improve and expand the fields of application of radiation and photodynamic therapy of cancer is the use of drugs containing nanosized phosphors. The aim of the work was to study the effect of the duration of hydrothermal synthesis and the conditions of rapid thermal annealing (RTA) on the Y2O3:Eu nanosized phosphors microstructure. The hydrothermal synthesis technique was carried out in two ways: chloride (precipitation from a chloride solution using NaOH and NH4OH precipitators) and acetate (decomposition of mixed acetate without a dispersant, as well as with PEG-200 and PEG-2000 dispersants). Hydrothermal synthesis was carried out at a temperature of 230 °C for 6–24 hours. Rapid thermal annealing was carried out at a temperature of 600–800 °C for 5–20 minutes. As a result of our work, the Y2O3:Eu nanosized phosphors which particle size does not exceed 200 nm is synthesized.
Kinetics of electrical characteristics of balanced SHF mixer based on resonant-tunnelling diodes under operational factors influence
Authors: Cherkasov K. V. , Meshkov S. A. , Makeev M. O. , Ivanov Yu. A. , Khlopov B. V.
Published: June 2020

The purpose of this study is to analyze the impact of high temperature and gamma-irradiation on the electrical characteristics of the balanced SHF mixer based on the resonant-tunnelling diodes during its operation. Failures caused by irreversible changes in the nonlinear element’s electrical characteristics under the mentioned operational factors’ effect investigated. Revealed that the failure is caused by the mixer’s combination frequency 1-1 conversion loss’ growth. Individual times to failure, matching the mixer’s actual operating conditions, were obtained.
To the choice of spectral region for laser based analysis of molecular gases at strong interference of absorption spectra
Authors: Stepanov E V , Kasoev S G , Yulina G N , Kotelnikov S N
Published: June 2020

The interference of the absorption bands of H2O, CO2, and several gaseous biomarkers was analyzed in the middle and near-IR spectral region using the HITRAN2006 database. It was demonstrated that the problem o f the vibration-r o tation band interfere nce for detected and interfering gases is aggravated in the near-IR spectral region. This aggravation is caused not only by the decrease in the absolute band intensity for overtones and combination bands of the molecular vibrations but also by the relative increase in the absorption in H2O lines and high density of CO2 lines in the near-IR spectral region
Simulation and analysis of physical characteristics of a molecular beam in a collimator using methods of kinetic theory
Authors: Komarov E , Kloss Yu Yu , Tcheremissine F G , Sazikina T A , Abannikov V V
Published: June 2020

The paper is dedicated to the study of gas outflow from a vessel for the case of a simple collimator and to the determination of molecular beam and collimator characteristics enabling a maximum reduction in the beam width. A software system was developed for studying gas flow in various geometries using the GP-GPU.
Computer models of gas-dynamic processes of radionuclides behavior in thermal emission converter of nuclear power plant
Authors: Sherbakov D V , Kloss Yu Yu , Yu Lyubimov D , Orazbaev A N , Tcheremissine F G , Tataurov P A , Knyazev A N
Published: June 2020

The paper is devoted to the application of numerical solution of the Boltzmann equation method for modeling the behavior of radionuclides (Xe and Kr) in the inter-electrode gap and the vacuum-cesium channel of a thermionic reactor-converter, which is used in a space nuclear power generator. In this work, we developed modeling techniques and implemented them in a software package, that is using the algorithm of simultaneous calculations for the left side of the Boltzmann equation. We performed series of calculations for different initial flux of radionuclides and evaluated the dependence of the radionulcides output flux on the input flux for two areas of the reactor.
Simulation of gas-dispersed flow particles’ interaction with a solid body
Authors: Amelyushkin I A , Stasenko A L
Published: June 2020

Mathematical models and numerical algorithms for the interaction of particles of an aerosol stream with a r elief surface of a s olid are developed as applied to the problem of aircraft icing. The developed technique allows to study the interaction of particles with a solid a various speeds and particles’ sizes the spreading coefficient characterizing the hydrophobic properties of the surface.
The influence of ice crystals on the evolution of run-back ice in mixed icing conditions
Authors: Kashevarov A V , Miller A B , Potapov Yu F , Stasenko A L , Tokarev O D , Zhbanov V A
Published: June 2020

In the framework of the development of physical and mathematical models of icing in crystalline and mixed conditions and their verification, the effect of ice crystals in the airflow on the evolution of run-back ice on the surface of a wing model for tests in icing facility is numerically studied. The results confirm that the experimentally observed change in the mass of ice deposits with the introduction of crystals into the flow is associated with the absorption of a part of the mass of crystals by the film at low flow rates and with the film splashing at higher speeds.
Study of Magnetic Field Influence on the Stationary Plasma Thruster Plume
Authors: Bishaev A M , Abgaryan M V
Published: June 2020

The purpose of this paper is to study the magnetic field influence on the stationary plasma thruster (SPT) plume. In consideration of collisionless motion of ions, it is possible to write an expression for distribution function for ions leaving a ring opening. Further, the pattern of ion density calculation is built as of the corresponding integral of distribution function. Results of calculations made using the constructed pattern are given.
The MHD stability investigation of an aluminum electrolyzer under various process conditions
Authors: Savenkova N P , Yu Mokin A , Udovichenko N S
Published: June 2020

For analysis, the MHD electrolyzer was adapted to a three-dimensional mathematical model, which uses a multiphase approach to the description of the medium (aluminum, electrolyte and gas), as well as to hydrodynamic, electromagnetic, thermal and electrochemical processes in the bath. Test calculations were carried out, which confirmed the model adequacy and the presence of the proposed numerical solutions to the problem with sufficient accuracy. The suggestion that the Soderberg electrolyzer is less MHD-stable than the multi-anode electrolyzer was confirmed. The impact on the MHD stability of various initial configurations forms has been assessed. The influence of a potential change on the MHD-stable form of the bath working space is investigated.
Interaction of corona discharge plasma with a disperse media
Authors: Bychkov V , Chernikov V , Deshko K , Goryachkin P , Mikhailovskaya T , Shvarov A
Published: June 2020

Results of experimental research on influence of corona discharge on the disperse medium - clay are described. The role of the corona discharge influence in the change of its electrical conductivity is revealed. Features of changes in the concentrations of certain chemical elements under the influence of the corona discharge on the clay have been revealed.
The electromagnetic problems of interplanetary spacecraft communication
Authors: Kirdyashev K P
Published: June 2020

The results of the radio frequency emission measurements from the ground-based experiments using electric propulsion engine applied to electromagnetic compatibility evaluation of spacecraft radio communication. The report presents the way of looking at the electromagnetic compatibility problem based on experimental and theoretical investigations of the physical foundation of the electromagnetic field generation by the electric propulsion engines. The approach under review allows evaluating the electromagnetic performance characteristics depending on thruster construction and engine operating modes.
Coefficient Bounds Problem For Functions associated with Universally Prestarlike Functions
Authors: Mary Joseph Lourthu , Shanmugam T N
Published: June 2020

Universally prestarlike functions of order α ≤ 1 in the slit domain Λ = C \ [1, ∞) have been introduced by S. Ruscheweyh. This notion generalizes the corresponding one for functions in the unit disk Δ (and other circular domains in C). In this paper, we obtain coefficient bounds for certain class of analytic functions associated with universally prestarlike function.
Classes of Analytic Functions Involving a Generalization by the Srivastava-Attiya Operator
Authors: Ghanim F , Aljarah Anas , Al-Janaby Hiba F
Published: June 2020

In this research article, we present a class defined by a new generalization operator

ϒ

(

χ
K

)
,
(
ω
ℓ
)
,
σ

μ
,
℘
,
χ
,
ε
,
ζ
,
ψ

one that is studied and investigated recently by many authors. We present several important properties for the function f (z) which belongs to the class

Ξ

(

χ
k

)
,
(

ω
ℓ

)
,
σ

μ
,
℘
,
χ

(
A
)

in the unit disc.
The Fifth Coefficients of Strongly Convex Functions
Authors: Daniswara Krisna Adilia , Marjono  , Bagus E W R
Published: June 2020

Let the function f be analytic in ↁ = {z : |z| < 1} and given by

f
(
z
)
=
z
+

∑

n
=
2

∞

a

n

z

n

. For 0 < α ≤ 1, let C(α) be the class of strongly convex functions defined by

|
arg
⁡

(
1
+

z

f

′
′

(
z
)

f

′

(
z
)

)

|

<

π
α

2

. We give sharp bounds for the fifth coefficient |a
5|.
The Existence of Global Weak Solutions for Singular Parabolic System of p-Laplacian Type
Authors: Akbar P R , Karim Corina , Bagus E W R
Published: June 2020

We study the existence of global weak solutions for Cauchy-Dirichlet problem forp-Laplacian systems in the singular case. Here, we treat the existence of global weak solutions using Galerkin method where the initial data belonging to the Sobolev spaceW1, p(Ω, ℝm). The main result is to show the validity of theorem of global weak solutions for Cauchy-Dirichlet problem for singular case only.
Tribological and physical performance of micro bearing concept for diluted epoxy filled with UHMWPE composite
Authors: Aizuddin Ariffin Ahmad , Zafir Romli Ahmad , Noor Idayu Nik Ibrahim Nik
Published: June 2020

Short fillers have been widely used as reinforcing agents due to their successful effects on composite materials. However, studies for short fillers were mainly focusing on even dispersion of fillers in the composite system. As for the application related to bearing, the fillers needed to be deposited on the surface to improve the physical and tribological properties. Therefore, in this study, the fundamental of micro bearing concept was imparted by relating to the rheological study of polymer. These relations can be supported by the theory of particulate fillers in suspensions according to Modified Mooney-Einstein’s Theory of Viscosity. The Ultra High Molecular Weight Polyethylene (UHMWPE) fillers, which possess high wear resistance, were fabricated with epoxy resin. The mixture was prepared by diluting with acetone solvent and varying the filler loadings percentage for 1%, 3%, 5%, 7%, and 10%, accordingly. Based on the results observed, there were increment up to 41.7% for viscosity value. For the wear test, the results showed decrease in the wear rate up to 72.0%. For the hardness test, the results indicate increment in the hardness value up to 94% compared to UHMWPE alone. For the density test, the results showed decrease in the density value up to 3.8%.
A novel semi-analytical solution to Jeffery-Hamel equation
Authors: Nourazar Salman , Dehghanpour Hamid Reza , Ramezani Mohammad
Published: June 2020

A new approach based on the Adomian decomposition and the Fourier transform is introduced. The method suggests a solution for the well-known magneto-hydrodynamic (MHD) Jeffery-Hamel equation. Results of Adomian decomposition method combined with Fourier transform are compared with exact and numerical methods. The FTADM as an exclusive and new method satisfies all boundary and initial conditions over the entire spatial and temporal domains. Moreover, using the FTADM leads to rapid approach of approximate results toward the exact solutions is demonstrated. The second derivative of Jeffery-Hamel solution related to the similar number of items of recursive terms under a vast spatial domain shows the maximum error in the order of

10

−
5

comparing to exact and numerical solutions. The results also imply that the FTADM can be considered as a precise approximation for solving the third-order nonlinear Jeffery-Hamel equations.
Cutaneous Involvement in Plasma Cell Myeloma
Authors: Panse Gauri , Subtil Antonio , McNiff Jennifer M , Glusac Earl J , Ko Christine J , Galan Anjela , Myung Peggy , Xu Mina L
Published: June 2020

Objectives

Plasma cell myeloma (PCM) involving skin is rare and occurs in 1% to 4% of patients with PCM. We evaluated the clinicopathologic features, cytogenetic findings and clinical follow-up in a series of PCM cases with cutaneous involvement.

Methods

Cases of PCM with cutaneous involvement were retrospectively reviewed with clinical data.

Results

Skin involvement in PCM occurred in older individuals (mean, 75 years) and was more frequent in men (7/10 patients). All cases showed bone marrow involvement preceding the cutaneous lesions. Histopathologically, the infiltrate was plasmacytic (n = 5) or primitive or plasmablastic (n = 4), and 1 case showed predominantly lymphoplasmacytic features with cyclin D1 immunoreactivity and CCND1 gene rearrangement. Concurrent amyloid deposition was seen in one biopsy, and another case demonstrated coexisting squamous cell carcinoma. The most common immunophenotype was CD138+, CD20–, and CD56+ with light chain restriction. Cytogenetic analysis (available for 7 cases) showed multiple hyperdiploid abnormalities. Follow-up was available for 8 cases (mean, 42 months; range, 11-156 months) and showed short-term disease-related death in 7 of 8 patients.

Conclusions

Cutaneous involvement in PCM demonstrates a diverse cytomorphologic spectrum with plasmacytic, plasmablastic, or lymphoplasmacytic features and may show concurrent amyloid deposition or neoplasms such as squamous cell carcinoma. Cutaneous involvement typically occurs late in the course of the disease and likely portends poor outcome.
A Case Report of Nicolau Syndrome After Aesthetic Breast Surgery: A Review of the Literature and Introduction to a New Treatment Modality
Authors: Gal Shaili , Dart Paul E , Movassaghi Kiya
Published: June 2020

Nicolau syndrome (NS) is a rare iatrogenic syndrome usually following intramuscular (IM) injection of various described medications. The typical presentation involves immediate injection site pain and development of a livedoid reticular patch, which can progress to muscle necrosis requiring surgical debridement. The pathophysiology is unclear, although vasoconstrictive etiologies have been implicated. Treatment ranges from supportive care to surgical debridement. The authors present a case report of this syndrome as well as a review of the literature and introduction to a new treatment modality. NS in a 52-year-old woman following IM injection of Demerol and Phenergan to address pain and nausea before discharge is reported. This occurred in the post-anesthesia care unit after aesthetic breast surgery in an ambulatory surgery center. Our patient had immediate injection site pain and a hemorrhagic patch was evident on her physical examination the following day. With local care and hyperbaric oxygen therapy, her lesion improved in appearance. However, she continued to have debilitating pain and was referred to a specialist for osteopathic manipulative therapy (OMT), which had the greatest impact on her pain level. After multi-modal therapy was initiated, the syndrome ultimately resolved without the need for surgical debridement. However, she continues to experience pain and ambulates with a limp due to muscle atrophy. NS is a rare diagnosis that can have devastating complications that can be averted by early recognition and initiation of treatment modalities. In this case, the authors introduced OMT as a new treatment modality, with the potential to improve the progression of this syndrome.

Level of Evidence: 5
TDAview: an online visualization tool for topological data analysis
Authors: Walsh Kieran , Voineagu Mircea A , Vafaee Fatemeh , Voineagu Irina
Published: June 2020

TDAview is an online tool for topological data analysis (TDA) and visualization. It implements the Mapper algorithm for TDA and provides extensive graph visualization options. TDAview is a user-friendly tool that allows biologists and clinicians without programming knowledge to harness the power of TDA. TDAview supports an analysis and visualization mode in which a Mapper graph is constructed based on user-specified parameters, followed by graph visualization. It can also be used in a visualization only mode in which TDAview is used for visualizing the data properties of a Mapper graph generated using other open-source software. The graph visualization options allow data exploration by graphical display of metadata variable values for nodes and edges, as well as the generation of publishable figures. TDAview can handle large datasets, with tens of thousands of data points, and thus has a wide range of applications for high-dimensional data, including the construction of topology-based gene co-expression networks.

Availability and implementation

TDAview is a free online tool available at https://voineagulab.github.io/TDAview/. The source code, usage documentation and example data are available at TDAview GitHub repository: https://github.com/Voineagulab/TDAview.
Does robot-assisted minimally invasive oesophagectomy have superiority over thoraco-laparoscopic minimally invasive oesophagectomy in lymph node dissection?
Authors: Li Xiao-Kun , Xu Yang , Zhou Hai , Cong Zhuang-Zhuang , Wu Wen-Jie , Qiang Yong , Shen Yi
Published: June 2020

Although robotic techniques have been used for oesophagectomy for many years, whether robot-assisted minimally invasive oesophagectomy (RAMIE) can actually improve outcomes and surpass thoraco-laparoscopic minimally invasive oesophagectomy (MIE) in the success rate of lymph node dissection remains to be empirically demonstrated. Therefore, we performed this systematic review and meta-analysis of case–control studies to systematically compare the effect of lymph node dissection and the incidence of vocal cord palsy between RAMIE and MIE. The PubMed, EMBASE, and Web of Science databases were systematically searched up to December 1, 2019, for case–control studies that compared RAMIE with MIE. Thirteen articles were included, with a total of 1,749 patients with esophageal cancer, including 866 patients in the RAMIE group and 883 patients in the MIE group. RAMIE yielded significantly larger numbers of total dissected lymph nodes (WMD = 1.985; 95% CI, 0.448–3.523; P = 0.011) and abdominal lymph nodes (WMD = 1.686; 95% CI, 0.420–2.951; P = 0.009) as well as lymph nodes along RLN (WMD = 0.729; 95% CI, 0.348–1.109; P < 0.001) than MIE. Additionally, RAMIE could significantly decrease estimated blood loss (WMD = -11.208; 95% CI, -19.358 to -3.058; P = 0.007) and the incidence of vocal cord palsy (OR = 0.624; 95% CI, 0.411–0.947; P = 0.027) compared to MIE. Compared with MIE, RAMIE resulted in a higher total lymph node yield and a higher lymph node yield in the abdomen and along RLN, along with reduced blood loss during surgery and the incidence of vocal cord palsy. Therefore, RAMIE could be considered to be a standard treatment, with less blood loss, lower incidence of vocal cord palsy, and more radical lymph node dissection, exhibiting superiority over MIE.
Guidance for Restarting Inflammatory Bowel Disease Therapy in Patients Who Withheld Immunosuppressant Medications During COVID-19
Authors: Siegel Corey A , Christensen Britt , Kornbluth Asher , Rosh Joel R , Kappelman Michael D , Ungaro Ryan C , Johnson Douglas Forsyth , Chapman Scott , Wohl David A , Mantzaris Gerassimos J
Published: June 2020

Patients with inflammatory bowel diseases [IBD] are frequently treated with immunosuppressant medications. During the coronavirus disease 2019 [COVID-19] pandemic, recommendations for IBD management have included that patients should stay on their immunosuppressant medications if they are not infected with the severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], but to temporarily hold these medications if symptomatic with COVID-19 or asymptomatic but have tested positive for SARS-CoV-2. As more IBD patients are infected globally, it is important to also understand how to manage IBD medications during convalescence while an individual with IBD is recovering from COVID-19. In this review, we address the differences between a test-based versus a symptoms-based strategy as related to COVID-19, and offer recommendations on when it is appropriate to consider restarting IBD therapy in patients testing positive for SARS-CoV-2 or with clinical symptoms consistent with COVID-19. In general, we recommend a symptoms-based approach, due to the current lack of confidence in the accuracy of available testing and the clinical significance of prolonged detection of virus via molecular testing.
Optimized approximate inverse Laplace transform for geo-deformation computation in viscoelastic Earth model
Authors: Tang He , Zhang Lan , Chang Le , Sun Wenke
Published: June 2020

Integral transformations, especially the inverse Laplace transform, are powerful techniques for resolving a wide range of geophysical and geodynamic simulation problems in viscoelastic materials. The exact location or distribution range of poles of the image function in a complex plane is usually necessary for applying numerical algorithms such as contour integration. Unfortunately, there are innumerable poles (such as those of post-seismic deformations) in a realistic Earth model with continuous stratification, finite compressibility and self-gravitation. Here, an optimized method to effectively calculate the inverse Laplace transform is presented. First, the integral kernel is approximated as a rational function with two parameters (a and m). Thereafter, the residue theorem is analytically applied to the approximated integrand. Finally, a series formula of the inverse Laplace transform sampling of image functions along a contour line parallel to the image axis is obtained. The proposed approximate scheme of the inverse Laplace transform is discussed by some common geophysical signals and the optimized selection of two parameters (a = 6 and m = 4) is conducted after a detailed analysis. The proposed method is anticipated as being able to help performing certain theoretical studies related to geodynamic problems with viscoelastic deformations.
Larval Dispersal Modeling Suggests Limited Ecological Connectivity Between Fjords on the West Antarctic Peninsula
Authors: Ziegler Amanda F , Hahn-Woernle Lisa , Powell Brian , Smith Craig R
Published: June 2020

Synopsis

Larval dispersal is a key process for community assembly and population maintenance in the marine environment, yet it is extremely difficult to measure at ecologically relevant spatio-temporal scales. We used a high-resolution hydrodynamic model and particle-tracking model to explore the dispersal of simulated larvae in a hydrographically complex region of fjords on the West Antarctic Peninsula. Modeled larvae represented two end members of dispersal potential observed in Antarctic benthos resulting from differing developmental periods and swimming behavior. For simulations of low dispersing larvae (pre-competency period = 8 days, settlement period = 15 days, swimming downward) self-recruitment within fjords was important, with no larval settlement occurring in adjacent fjords <50 km apart. For simulations of highly dispersing organisms (pre-competency period = 35–120 days, settlement period = 30–115 days, no swimming behavior), dispersal between fjords occurred when larvae were in the water column for at least 35 days, but settlement was rarely successful even for larvae spending up to 150 days in the plankton. The lack of ecological connectivity between fjords within a single spawning event suggests that these fjords harbor ecologically distinct populations in which self-recruitment may maintain populations, and genetic connectivity between fjords is likely achieved through stepping-stone dispersal. Export of larvae from natal fjord populations to the broader shelf region (>100 km distance) occurred within surface layers (<100 m depth) and was enhanced by episodic katabatic wind events that may be common in glaciomarine fjords worldwide.
A lumped-parameter model for kidney pressure during stone removal
Authors: Williams J G , Rouse L , Turney B W , Waters S L , Moulton D E
Published: June 2020

In this paper, we consider a lumped-parameter model to predict renal pressures and flow rate during a minimally invasive surgery for kidney stone removal, ureterorenoscopy. A ureteroscope is an endoscope designed to work within the ureter and the kidney and consists of a long shaft containing a narrow, cylindrical pipe, called the working channel. Fluid flows through the working channel into the kidney. A second pipe, the ‘access sheath’, surrounds the shaft of the scope, allowing fluid to flow back out of the urinary system. We modify and extend a previously developed model ( Oratis et al., 2018) through the use of an exponential, instead of linear, constitutive law for kidney compliance and by exploring the effects of variable flow resistance, dependent on the presence of auxiliary ‘working tools’ in the working channel and the cross-sectional shapes of the tools, working channel, scope shaft and access sheath. We motivate the chosen function for kidney compliance and validate the model predictions, with ex vivo experimental data. Although the predicted and measured flow rates agree, we find some disagreement between theory and experiment for kidney pressure. We hypothesize that this is caused by spatial pressure variation in the renal pelvis, i.e. unaccounted for in the lumped-parameter model. We support this hypothesis through numerical simulations of the steady Navier–Stokes equations in a simplified geometry. We also determine the optimal cross-sectional shapes for the scope and access sheath (for fixed areas) to minimize kidney pressure and maximize flow rate.
Fast and spectrally accurate numerical methods for perforated screens (with applications to Robin boundary conditions)
Authors: Colbrook Matthew J , Priddin Matthew J
Published: June 2020

This paper considers the use of compliant boundary conditions to provide a homogenized model of a finite array of collinear plates, modelling a perforated screen or grating. While the perforated screen formally has a mix of Dirichlet and Neumann boundary conditions, the homogenized model has Robin boundary conditions. Perforated screens form a canonical model in scattering theory, with applications ranging from electromagnetism to aeroacoustics. Interest in perforated media incorporated within larger structures motivates interrogating the appropriateness of homogenized boundary conditions in this case, especially as the homogenized model changes the junction behaviour considered at the extreme edges of the screen. To facilitate effective investigation we consider three numerical methods solving the Helmholtz equation: the unified transform and an iterative Wiener–Hopf approach for the exact problem of a set of collinear rigid plates (the difficult geometry of the problem means that such methods, which converge exponentially, are crucial) and a novel Mathieu function collocation approach to consider a variable compliance applied along the length of a single plate. We detail the relative performance and practical considerations for each method. By comparing solutions obtained using homogenized boundary conditions to the problem of collinear plates, we verify that the constant compliance given in previous theoretical research is appropriate to gain a good estimate of the solution even for a modest number of plates, provided we are sufficiently far into the asymptotic regime. We further investigate tapering the compliance near the extreme endpoints of the screen and find that tapering with $\tanh $ functions reduces the error in the approximation of the far field (if we are sufficiently far into the asymptotic regime). We also find that the number of plates and wavenumber has significant effects, even far into the asymptotic regime. These last two points indicate the importance of modelling end effects to achieve highly accurate results.
Increasing dietary tryptophan in conjunction with decreasing other large neutral amino acids increases weight gain and feed intake in weaner pigs regardless of experimental infection with enterotoxigenic Escherichia coli
Authors: Sterndale Samantha O , Miller David W , Mansfield Josie P , Kim Jae C , Pluske John R
Published: June 2020

Dietary tryptophan (Trp) is a precursor for serotonin, a neuromediator involved in stress responses. Tryptophan competes with other large neutral amino acids (LNAA: tyrosine, isoleucine, leucine, valine, and phenylalanine) to cross the blood–brain barrier; therefore, the regulation of circulating LNAA can influence Trp availability in the cortex and serotonin biosynthesis. The hypothesis examined in this study was that increased supplementation of dietary Trp and a reduction in LNAA for weaned pigs experimentally infected with enterotoxigenic Escherichia coli (ETEC; F4) will increase Trp availability in plasma and reduce indices of the stress response, which will translate to reduced production losses. At 21 ± 3 d of age (mean ± SEM), 96 male pigs (Large White × Landrace) weighing 6.3 ± 0.98 kg (mean ± SEM) were individually penned and allocated to a 4 × 2 factorial arrangement of treatments, with respective factors being 1) four dietary standardized ileal digestible (SID) Trp and LNAA contents, being HTrpHLNAA (Low Trp-High LNAA; 0.24% SID Trp: 5.4% SID LNAA), HTrpHLNAA (Low Trp-Low LNAA; 0.24% SID Trp: 4.6% SID LNAA), HTrpHLNAA (High Trp-High LNAA; 0.34% SID Trp: 5.4% SID LNAA), and HTrpHLNAA (High Trp-Low LNAA; 0.34% SID Trp: 4.6% SID LNAA), and 2) without/with ETEC infection. Pigs were orally infected with 0.8 mL (3.6 × 109 CFU/mL) ETEC at days 7 and 8 after weaning. Pigs fed diets high in Trp irrespective of the level of LNAA (HTrpHLNAA and HTrpLLNAA) had higher plasma Trp concentrations (P < 0.001) and a Trp:LNAA ratio (P < 0.001) before infection and 6 d after infection. Following infection, noninfected pigs had higher plasma Trp (P = 0.03) and a Trp:LNAA ratio (P = 0.004) compared with pigs infected with ETEC. Plasma cortisol levels after infection were higher in ETEC-infected pigs (P = 0.05) and altering dietary Trp and LNAA concentrations did not influence (P > 0.05) plasma cortisol. Pigs fed diet HTrpLLNAA had higher serum serotonin levels 24 h after infection (P = 0.02) compared with pigs fed diets LTrpLLNAA and HTrpHLNAA. Similarly, pigs fed diet HTrpLLNAA had a higher (P = 0.02) average daily gain during the 3-wk study. Overall, average daily feed intake tended to be higher in pigs fed an HTrpLLNAA diet compared with the other diets (P = 0.08). These results suggest that the increased supplementation of dietary Trp with reduced LNAA increased circulating Trp levels that, in turn, likely caused higher serum serotonin levels, irrespective of infection with ETEC, and improved aspects of post-weaning performance.