bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiband low‐cost fractal antenna based on parasitic split ring resonators
Authors: Sharma Vipul , Lakwar Neeraj , Kumar Nitin , Garg Tanuj
Published: December 2017

This study presents the design of a low‐cost fractal antenna loaded with parasitic edge‐coupled (EC) split ring resonators (SRR). Parasitic EC SRR elements result in improved impedance matching leading to improved bandwidth. The basic resonant structure is a circular patch antenna designed at 3.2 GHz on low‐cost FR4 substrate with relative permittivity 4.4, and 1.6 mm thickness. A single iteration of circular patch and slots is used to make it fractal and in order to achieve multiband performance, the antenna is inset fed by a 50 Ω microstrip line. A prototype of the proposed antenna is fabricated and tested for results, a comparison between fractal antenna with and without SRRs is made and the results confirm that a better impedance matching is achieved in the later case, also a 3% increase in bandwidth is achieved at 8.5 GHz. A good agreement between simulated and measured results is obtained, an estimated gain of 13.3 dB is provided by the proposed antenna. The overall dimensions of the antenna are 45 mm × 45 mm and it may be used for wireless applications at 3, 5, 6.8, 7.5 and 8.5 GHz with an average bandwidth of 200 MHz.
Reconfigurable dielectric resonator antenna with multiple polarisation states
Authors: Dhar Sayantan , Patra Kaushik , Ghatak Rowdra , Gupta Bhaskar , Poddar Dipak Ranjan
Published: December 2017

The realisation of an electronically tuned polarisation reconfigurable dielectric resonator antenna with multiple switchable states is described in this study. The antenna is fed by a microstrip line through a cross‐slot aperture placed in the ground plane to achieve circular polarisation. PIN diodes have been placed across the cross slots to control their effective dimensions and thereby its sense of polarisation. The antenna is connected to a microcontroller (ARDUINO‐UNO) to switch between corresponding polarisation states. Simulated results of the antenna are verified with experimental data. The antenna has an impedance bandwidth of about 20% for all four states of polarisations. The antenna also radiates with a gain of 4 dB over the entire band.
Deadbeat control for a single‐phase cascaded H‐bridge rectifier with voltage balancing modulation
Authors: Qi Chen , Chen Xiyou , Tu Pengfei , Wang Peng
Published: December 2017

The model predictive control (MPC) is a promising control method for cascaded H‐bridge (CHB) rectifiers. One well‐known MPC method is the finite‐control‐set MPC (FCS‐MPC). However, three main issues arise in FCS‐MPC: heavy computational burden, low steady‐state performance, and time‐consuming tuning work of weighting factor. Here, an alternative MPC method, deadbeat (DB) control with a capability of voltage balance, has been proposed for a single‐phase CHB rectifier. The proposed method is based on the DB solution to obtain zero current error at the sampling instant and the use of a redundancy‐based modulation strategy for voltage balance, leading to the ease of controller design and elimination of tuning work. The proposed method has been evaluated against FCS‐MPC method on a single‐phase three‐cell CHB rectifier. The experimental results show that a reduced computational burden, an improved steady‐state performance, and a comparable dynamic response can be achieved in the proposed method in comparison with FCS‐MPC method.
Dead‐time effect analysis of a three‐phase dual‐active bridge DC/DC converter
Authors: Wang Deqiang , Peng Fei , Ye Jin , Yang Yinye , Emadi Ali
Published: December 2017

The dead‐time effect is observed in the three‐phase dual‐active bridge (DAB) DC/DC converter. The occurrence of the dead‐time effect depends on the relationship of the switching frequency, the phase shift value, the dead‐time value and the equivalent conversion ratio. The dead‐time effect may have a significant impact on the converter performance when high switching frequency, wide input and output voltage range or wide operation power range are required. Therefore, comprehensive research of the dead‐time effect is essential to improve the design of the three‐phase DAB converter over a wide operation range. In this study, all the cases of the dead‐time effect in the three‐phase DAB converter are analysed in terms of the buck, boost, and matching states. The expressions of the transmission power, constraint conditions, and key time of the dead‐time effect are derived for each state. The operation waveforms of the dead‐time effect are also presented to better understand the dead‐time effect. Finally, the analysis is verified by both simulation and experimental results.
Polarimetric detection and range estimation for a point‐like target in non‐Gaussian clutter
Authors: Shen Lei , Liu Zhiwen , Xu Yougen
Published: December 2017

In this study, a method is presented to deal with the problem of polarimetric detection of a point‐like target with energy spillover in non‐Gaussian clutter. Consecutive range samples are employed to enhance the detection and range estimation performances. Within the framework of the generalised likelihood ratio test, the decision statistic of the proposed polarimetric detector involves the textures and the covariance structure of the clutter, the target return, and the residual delay. Suitable estimates of these parameters are plugged into the decision statistic. Simulations show that, the proposed detector achieves a considerable performance improvement over the polarimetric adaptive detectors that ignore either the non‐Gaussian clutter or the spillover, in terms of both the probability of detection and the root mean squared error of range estimation.
Preparation of amphiphilic Janus particles and their application in stabilising foams
Authors: Wang Keliang , Wang Gang , Lu Chunjing , Wang Ying
Published: December 2017

This work presents the preparation of foaming Janus particles (JPs) decorated with fluorinated chains by the Pickering emulsion method and investigates their self‐assembly behaviour at the air–water interface and foam stability under a limited range of concentrations. When the particle concentration reached 0.6 wt%, the adsorption of the JPs at the interface was saturated and the equilibrium surface tension dropped to around 38 mN/m even after an increase in the particle concentration. When the particle concentration reached 0.4 wt%, the Gibbs stability criterion was fulfilled. During the observation period, the foam volume was maintained relatively constant and the bubble size exhibited no significant changes. Additionally, the liquid fraction of the foam exhibited static equilibrium at different observed concentrations, which demonstrated effective drainage arrest. Overall, the present work validated the efficiency of the fluorinated JPs in stabilising the foams.
Facile formation of colloidal silver nanoparticles using electrolysis technique and their antimicrobial activity
Authors: Lai Chin Wei
Published: December 2017

In this research work, colloidal silver nanoparticles were successfully produced via an electrolysis method and their antibacterial activity was evaluated. This study aims to determine the optimum concentration of colloidal silver nanoparticles to produce an effective inhibition zone for Escherichia coli bacteria growth. Based on the results obtained, the applied current and reaction times during the electrolysis played a crucial role in determining the colloidal silver nanoparticles’ concentration (ppm). It was found that a minimum content of colloidal silver nanoparticles (0.02 ppm) was required to perform the 0.1 mm inhibition zone diameter on agar medium spread with E. coli bacteria. Interestingly, high concentrations of colloidal silver nanoparticles could exhibit high conductivity (µS/cm) as well as the high intensity of the maximum plasmon peak from the UV/vis absorption spectra at about 390 nm. In conclusion, this research work revealed the destruction of the cytoplasmic membrane and the rupture of the internal organisation of E. ‐coli bacteria, leading to the leakage of the cytoplasmic contents and cell death after having contact with sufficient concentration of colloidal silver nanoparticles.
Stability criteria for wide binary stars harboring Oort Clouds
Authors: Calandra M. F. , Correa-Otto J. A. , Gil-Hutton R. A.
Published: December 2017

Context. In recent years, several numerical studies have been done in the field of the stability limit. Although, many of them included the analysis of asteroids or planets, is not possible to find in the literature any work on how the presence of a binary star could affect other possible configurations in a three-body problem. In order to develop this subject we consider other structures like Oort Clouds in wide binary systems. Regarding the existence of Oort Clouds in extrasolar systems there are recent works that do not reject its possible existence.

Aim. The aim of this work is to obtain the stability limit for Oort Cloud objects considering different masses of the secondary star and zero and non-zero inclinations of the particles. We improve our numerical treatment getting a mathematical fit that allows us to find the limit and compare our results with other previous works in the field.

Methods. We use a symplectic integrator to integrate binary systems where the primary star is m1 = 1 M⊙ and the secondary, m2, takes 0.25 M⊙ and 0.66 M⊙ in two sets of simulations S1 and S2. The orbital parameters of the secondary star were varied in order to study different scenarios. We also used two different integration times (one shorter than the other) and included the presence of 1000 to 10 000 massless particles in circular orbits to form the Oort Cloud. The particles were disposed in four different inclination planes to investigate how the presence of the binary companion could affect the stability limit.

Results. Using the Maximum Eccentricity Method, emax, together with the critical semimajor axis acrit we found that the emax criteria could reduce the integration times to find the limit. For those cases where the particles were in inclined orbits we found that there are particle groups that survive the integration time with a high eccentricity. These particle groups are found for our two sets of simulations, meaning that they are independent of the secondary mass. We also find for the co-planar case that the numerical value of the stability limit for retrograde orbits is higher than those found for prograde orbits. These results are in agreement with several published studies. Finally, the results obtained in this work allow us to build a numerical expression depending of the mass ratio, e2 and ip to find acrit, which can be compared with other recent works in the field.
Green Synthesis of Pyrido[2,1-a]isoquinolines and Pyrido[1,2-a]quinolines by Using ZnO Nanoparticles
Authors: Sheikholeslami-Farahani Fatemeh , Ghazvini Maryam , Soleimani-Amiri Somayeh , Salimifard Masoomeh , Rostamian Rezvaneh
Published: December 2017

Pyrido[2,1-a]isoquinoline and pyrido[1,2-a]quinoline derivatives have been produced in good yields by the reaction of isoquinoline or quinoline, activated acetylenic compounds, α-halo ketones, and triphenylphosphine in the presence of ZnO nanoparticles (NPs) as an efficient catalyst under solvent-free conditions at room temperature. The reaction workup is easy, and the products can be readily separated from the reaction mixture. ZnO NPs markedly improved the yield of the product. The catalyst showed significant reusable activity.
Buprenorphine for Medication-Assisted Treatment of Opioid Use Disorder in Pregnancy: Relationship to Neonatal Opioid Withdrawal Syndrome
Authors: Chavan Niraj , Ashford Kristin , Wiggins Amanda , Lofwall Michelle , Critchfield Agatha
Published: December 2017

Objective To examine the relationship between antepartum buprenorphine dose for medication-assisted treatment (MAT) of opioid use disorder (OUD) and incident neonatal opioid withdrawal syndrome (NOWS).

Study Design We performed a prospective cohort study of pregnant women with a singleton gestation diagnosed with OUD and receiving buprenorphine for MAT at a tertiary care academic institution from July 2015 to January 2017. We divided the study cohort into two groups—pregnancies with versus without NOWS. Substance abuse patterns in pregnancy, maternal, and neonatal clinical outcomes were compared.

Results The incidence of NOWS was 31.11% (n = 28/90) in our study cohort. Pregnancies with NOWS had a significantly higher rate of benzodiazepine positive urine tests and number of positive urine drug screen (UDS) results for illicit opioids. The group without NOWS had significantly higher number of patients with an appropriate UDS result at delivery through postpartum. Rates of neonatal intensive care unit (NICU) admission, length of NICU stay, and maximum Finnegan score were significantly higher in the group with NOWS. Neither the initial (10.6 ± 5.2 versus 10.3 ± 4.8 mg, p = 0.80) nor the final buprenorphine doses (13.3 ± 5.1 versus 13.0 ± 4.6 mg, p = 0.81) were significantly different between study groups.

Conclusion The occurrence of NOWS was not related to buprenorphine dose used for MAT.
Factors Affecting Longer Surgical Times in Total Knee Arthroplasty for Obese Patients—A Comparative Study between High- and Nonhigh-Volume Surgeons
Authors: Harato Kengo , Kobayashi Shu , Nagashima Masaki , Hasegawa Takayuki , Tanikawa Hidenori , Maeno Shinichi , Nomoto So
Published: December 2017

Obesity has a negative influence on surgical times in total knee arthroplasty (TKA). Our purpose in this multicenter study was to compare surgical times between high- (HV) and nonhigh-volume (NHV) surgeons and clarify the important factors affecting longer surgical times in primary TKA for obese patients. A total of 798 knees, average age 75.1 years, were enrolled. All TKAs were done using the same measured resection technique by 25 surgeons at 12 facilities and were divided into three groups based on body mass index (kg/m2) of the patients (Group A: <24.9, Group B: 25–29.9, Group C: ≥30). Operative techniques including four surgical steps (surgical exposure, bone cutting, trial and fixation of the permanent component, and wound closure) were evaluated both in HV and NHV surgeons. In classifying surgeon volume, HV surgeons had performed >100 TKAs annually for many years, and other surgeons who had performed <100 TKAs annually were defined as NHV surgeons. Patient demographics, surgical details, and surgical times in each phase were compared using nonrepeated measures of analysis of variance and a post hoc Student–Newman–Keuls test. A total of 331, 327, 140 TKAs were allocated to Groups A, B, C, respectively. Regarding patient demographics, patients in Group C were younger and had the worst ranges of motion. The longest surgical time was observed in Group C of NHV surgeons (p < 0.05). Concerning each surgical phase, surgeons took much more time in surgical exposure and fixation of the permanent component for obese patients in NHV surgeons (p < 0.05). Our results suggest that younger age and lower range of motion were observed in obese patients, which led to longer surgical times. In addition, NHV surgeons took much time in surgical exposure and fixation of the permanent component for obese patients, while surgical time was similar among groups for HV surgeons.
Predictive relevance of lymphovascular invasion in T1 colorectal cancer before endoscopic treatment
Authors: Inoki Kazuya , Sakamoto Taku , Takamaru Hiroyuki , Sekiguchi Masau , Yamada Masayoshi , Nakajima Takeshi , Matsuda Takahisa , Taniguchi Hirokazu , Sekine Shigeki , Kanemitsu Yukihide , Ohe Yuichiro , Saito Yutaka
Published: December 2017

Background and aim The depth of tumor invasion is currently the only reliable predictive risk factor for lymph node metastasis before endoscopic treatment for colorectal cancer. However, the most important factor to predict lymph node metastasis has been suggested to be lymphovascular invasion rather than the depth of invasion. Thus, the aim of this study was to investigate the predictive relevance of lymphovascular invasion before endoscopic treatment.

Methods The data on pT1 colorectal cancers that were resected endoscopically or surgically from 2007 to 2015 were retrospectively reviewed. The cases were categorized into two groups: positive or negative for lymphovascular invasion. The following factors were evaluated by univariate and multivariate analyses: age and sex of the patients; location, size, and morphology of the lesion; and depth of invasion.

Results The positive and negative groups included 229 and 457 cases, respectively. Younger age (P < 0.01), smaller lesion size (P = 0.01), non-LST (LST: laterally spreading tumor) (P < 0.01), presence of depression (P < 0.01), and pT1b (P < 0.01) were associated with lymphovascular invasion. In multivariate analysis, younger age (comparing patients aged ≤ 64 years with those aged > 65 years, OR, 1.81; 95 %CI, 1.29 – 2.53), presence of depression (OR, 1.97; CI, 1.40 – 2.77), non-LST features (OR, 1.50; CI, 1.04 – 2.15), and pT1b (OR, 3.08; CI, 1.91 – 4.97) were associated with lymphovascular invasion.

Conclusion Younger age, presence of depression, T1b, and non-LST are associated with lymphovascular invasion. Therefore, careful pathological diagnosis and surveillance are necessary for lesions demonstrating any of these four factors.
Haben multimodale und perioperative Therapiestrategien das Überleben nach onkologischer Ösophaguschirurgie in den letzten 2 Dekaden verändert? Eine retrospektive Kohortenanalyse über 23 Jahre
Authors: Lingohr Philipp , Zender Julia , van Beekum Cornelius , Dohmen Jonas , Matthaei Hanno , Schaefer Nico , Kalff Jörg , Vilz Tim
Published: December 2017

Hintergrund Malignome des Ösophagus zählen zu den häufigsten krebsbedingten Todesursachen. Den einzigen kurativen Therapieansatz stellt die radikale Ösophagektomie, eingebettet in ein multimodales Therapiekonzept, dar. Ziel der Untersuchung war die Analyse von Langzeitentwicklungen in der operativen Therapie des Ösophaguskarzinoms und deren Einflüsse auf das kurz- (1-JÜR), mittel- (5-JÜR) und langfristige (10-JÜR) Überleben.

Patienten und Methoden Es wurden retrospektiv 301 Patienten am Universitätsklinikum Bonn untersucht, bei denen zwischen 1989 und 2012 eine Ösophagusresektion durchgeführt wurde. Um mögliche Trends im Management und Veränderungen hinsichtlich der Prognose zu analysieren, wurden 2 Kohorten (Kohorte A: operiert 1989 – 2000, Kohorte B: operiert 2001 – 2012) gebildet und bez. demografischer Daten, Tumorentität, Stadium, Komplikationsrate und Überleben miteinander verglichen.

Ergebnisse In der Kohorte B wurden signifikant ältere Patienten in niedrigeren Tumorstadien mit einer größeren Lymphknotenausbeute operiert, eine Zunahme des Adenokarzinoms (AC) war zu beobachten. Während sich die Gesamtmorbidität nicht signifikant veränderte, konnte eine geringere Rate an Anastomoseninsuffizienzen in Kohorte B (5,5%) verglichen mit Kohorte A (12,3%) bei gleichzeitigem Anstieg der kardialen Ereignisse (A: 3,6% vs. B: 12,3%) nachgewiesen werden. Die 30-Tage-Krankenhausmortalität lag bei insgesamt 2,7% und fiel von 5% (Kohorte A) signifikant (p = 0,05) auf 0,7% (Kohorte B). Das mittlere Überleben betrug in der Kohorte A 46 ± 6,5 Monate. In Kohorte B überlebten Patienten mit 53 ± 7,2 Monaten signifikant länger (p = 0,03). In der univariaten Analyse hatten das lokale Tumorstadium, der Resektionsgrad, die Anzahl der befallenen Lymphknoten (LK), der Lymphknotenquotient (LNR) sowie das Auftreten postoperativer Komplikationen einen Einfluss auf das Überleben, wohingegen in der multivariaten Analyse nur noch T-Stadium, R-Status und LNR als unabhängige Prognosefaktoren galten.

Schlussfolgerung Patienten, die sich einer onkologischen Ösophagusresektion unterziehen, sind heutzutage älter als noch vor einigen Jahren. Die frühzeitigere Tumordiagnose, eine radikalere Operationstechnik mit radikalerer Lymphknotendissektion und weniger Anastomoseninsuffizienzen sowie eine verbesserte perioperative Medizin scheinen diesen demografischen Nachteil zu kompensieren. Die größte prognostische Bedeutung beim Ösophaguskarzinom hat die LNR.
„Das liegt an jedem selbst“ - Eine qualitative Studie zu Versorgungsungleichheiten aus Patientensicht
Authors: Schröder Sara Lena , Martin Olaf , Mlinarić Martin , Richter Matthias
Published: December 2017

Ziel der Arbeit Ziel der qualitativen Studie ist es, erstmalig die subjektive Wahrnehmung aus Patientensicht von Ungleichheit in der gesundheitlichen Versorgung zu explorieren.

Methodik Analysiert wurden teilstandardisierte Interviews mit 44 Patienten zwischen 59 und 80 Jahren, die 2014 und 2015 im Universitätsklinikum Halle/Saale geführt wurden. Die Datenauswertung erfolgte induktiv mithilfe der qualitativen Inhaltsanalyse.

Ergebnisse Ein Großteil (82%) der Patienten nahm Versorgungsungleichheiten wahr. Dimensionen von Versorgungsungleichheit waren aus Sicht der Patienten regionale Unterschiede, der Krankenversicherungsstatus, die Qualität des Arztes und die Patienten selbst (Einkommen, Alter). Das Engagement der Patienten bei der Inanspruchnahme war die am häufigsten genannte Dimension von Versorgungsungleichheit, die jedoch von den Patienten nicht als Benachteiligung bewertet wurde. Ungleichheiten wirkten sich aus Sicht der Patienten v. a. im ambulanten Sektor (z. B. Wartezeiten, Zeitmangel) aus. Als Hauptgrund für die Entstehung von Versorgungsungleichheiten wurde die Ökonomisierung im Gesundheitssystem gesehen. Es zeigten sich keine relevanten Unterschiede in der Sichtweise zwischen Patienten mit hohem und niedrigem Sozialstatus.

Schlussfolgerung Der Kompetenz, sich in der Gesundheitsversorgung orientieren und engagieren zu können sowie den Zugangsbarrieren zum ambulanten Sektor wird aus Sicht der Patienten der größte Stellenwert beim Abbau von Ungleichheiten in der Versorgung zugeschrieben.
Equation of state and Helmholtz free energy for the atomic system of the repulsive Lennard-Jones particles
Authors: Mirzaeinia Ali , Feyzi Farzaneh , Hashemianzadeh Seyed Majid
Published: December 2017

Simple and accurate expressions are presented for the equation of state (EOS) and absolute Helmholtz free energy of a system composed of simple atomic particles interacting through the repulsive Lennard-Jones potential model in the fluid and solid phases. The introduced EOS has 17 and 22 coefficients for fluid and solid phases, respectively, which are regressed to the Monte Carlo (MC) simulation data over the reduced temperature range of 0.6≤T*≤6.0 and the packing fraction range of 0.1 ≤ η ≤ 0.72. The average absolute relative percent deviation in fitting the EOS parameters to the MC data is 0.06 and 0.14 for the fluid and solid phases, respectively. The thermodynamic integration method is used to calculate the free energy using the MC simulation results. The Helmholtz free energy of the ideal gas is employed as the reference state for the fluid phase. For the solid phase, the values of the free energy at the reduced density equivalent to the close-packed of a hard sphere are used as the reference state. To check the validity of the predicted values of the Helmholtz free energy, the Widom particle insertion method and the Einstein crystal technique of Frenkel and Ladd are employed. The results obtained from the MC simulation approaches are well agreed to the EOS results, which show that the proposed model can reliably be utilized in the framework of thermodynamic theories.
Water-water correlations in electrolyte solutions probed by hyper-Rayleigh scattering
Authors: Shelton David P.
Published: December 2017

Long-range ion-induced correlations between water molecules have been observed by second-harmonic or hyper-Rayleigh scattering experiments with conflicting results. The most recent work observed a large difference between the results for H2O and D2O, and large discrepancies with the previously proposed theory. However, the present observations are in quantitative agreement with the model where the ion electric field induces second harmonic generation by the water molecules, and ion-ion correlations given by the Debye-Huckel theory account for intensity saturation at high ion concentration. This work compares experimental results with theory and addresses the apparent discrepancies with previous experiments.
Disorder-dominated linear magnetoresistance in topological insulator Bi2Se3 thin films
Authors: Wang Wen Jie , Gao Kuang Hong , Li Qiu Lin , Li Zhi-Qing
Published: December 2017

The linear magnetoresistance (MR) effect is an interesting topic due to its potential applications. In topological insulator Bi2Se3, this effect has been reported to be dominated by the carrier mobility (μ) and hence has a classical origin. Here, we study the magnetotransport properties of Bi2Se3 thin films and observe the linear MR effect, which cannot be attributed to the quantum model. Unexpectedly, the linear MR does not show the linear dependence on μ, in conflict with the reported results. However, we find that the observed linear MR is dominated by the inverse disorder parameter 1/kFl, where kF and l are the Fermi wave vector and the mean free path, respectively. This suggests that its origin is also classical and that no μ-dominated linear MR effect is observed which may be due to the very small μ values in our samples.
Shear-flow driven dissipative instability and investigation of nonlinear drift-vortex modes in dusty plasmas with non-thermal ion population
Authors: Gul-e-Ali  , Masood W. , Mirza Arshad M.
Published: December 2017

The shear flow in dust dynamics driven waves in combination with the dust-neutral drag is studied in a plasma comprising of ions, electrons, and dust. Non-thermal population of ions is considered, which has been observed by many satellite missions. It is found that the dissipative instability produced by dust sheared flow and dust-neutral drag gets modified by the presence of nonthermal ions. It is found that the dissipative instability enhances for the Cairns distribution, whereas the kappa distribution arrests the growth of this instability. In the nonlinear regime, the formation of vortices in the system is studied. It is found that the nonthermal population of ions significantly alters these structures in comparison with their Maxwellian counterpart. The results obtained in this paper may have relevance in the planetary magnetospheres where the dust particles are present and non-Maxwellian distribution of particles have been observed by Freja and Viking satellites.
Effects of nanoparticle heating on the structure of a concentrated aqueous salt solution
Authors: Sindt Julien O. , Alexander Andrew J. , Camp Philip J.
Published: December 2017

The effects of a rapidly heated nanoparticle on the structure of a concentrated aqueous salt solution are studied using molecular dynamics simulations. A diamond-like nanoparticle of radius 20 Å is immersed in a sodium-chloride solution at 20% above the experimental saturation concentration and equilibrated at T = 293 K and P = 1 atm. The nanoparticle is then rapidly heated to several thousand degrees Kelvin, and the system is held under isobaric-isoenthalpic conditions. It is observed that after 2–3 ns, the salt ions are depleted far more than water molecules from a proximal zone 15–25 Å from the nanoparticle surface. This leads to a transient reduction in molality in the proximal zone and an increase in ion clustering in the distal zone. At longer times, ions begin to diffuse back into the proximal zone. It is speculated that the formation of proximal and distal zones, and the increase in ion clustering, plays a role in the mechanism of nonphotochemical laser-induced nucleation.
Effects of anisotropy field dispersion and grain boundary on coercivity and squareness ratio for HDDR-processed NdFeB powders
Authors: Akagi Fumiko , Ishii Yoshitake
Published: December 2017

In this study, we simulated the effects of the anisotropy field (Hk) dispersion of the grains (the main phases and the deterioration layers) for a NdFeB magnetic powder on Hc and squareness ratio in consideration of the magnetic properties of the grain boundaries and the deterioration layer of the grain surface using a micromagnetic simulator. The Hc decreases as increasing the coefficient variation of Hk (σHk/; σHk: standard deviation, : average) of the grain for the soft magnetic grain boundary, however, is independent of the σHk/ for the non-magnetic grain boundary. The squareness ratio is 1.0 up to a σHk/ of 25% for the soft magnetic grain boundary, however, decreases as the σHk/ increases for the non-magnetic grain boundary. Comparing the calculation and experimental values, when the grain boundary was non-magnetic and the σHk/ was 25 to 30%, the Hc and the squareness ratio were close to the experimental values.
The tanh solution of KdV-B equation in four-component quantum plasma by taking into account dust charge variation
Authors: Pishbin Noushin , Rouhani Mahmoud Reza
Published: December 2017

Nonlinear propagation of quantum dust-ion acoustic shock and solitary waves in an unmagnetized and collisionless four-component plasma medium containing inertialess quantum electrons and positrons, and also classical ions and stationary negative dust grains, which are affected by dust charge variations and viscosity of ions, are investigated using a quantum hydrodynamic model by employing the tanh method. The Korteweg–de Vries-Burgers and the Korteweg–de Vries equations indicate the behavior of shocks and solitons in this plasma model, respectively. Consideration of the dust charge variation requires the evaluation of charging currents. These currents are determined with the orbit limited motion theory and using the corresponding velocity distribution function. In the following, the effects of chemical potential and the density of dust grains on the structure of oscillatory and monotonic shock waves and solitary waves are investigated. The current study extends our understanding of the characteristics of quantum nonlinear structures in superdense astrophysical systems, inertial confinement fusion plasmas, and ultrasmall micro- and nano- electronic devices.
Particle-in-cell simulation of Buneman instability beyond quasilinear saturation
Authors: Rajawat Roopendra Singh , Sengupta Sudip
Published: December 2017

Spatio-temporal evolution of Buneman instability has been followed numerically till its quasilinear quenching and beyond, using an in-house developed electrostatic 1D particle-in-cell (PIC) simulation code. For different initial drift velocities and for a wide range of electron to ion mass ratios, the growth rate obtained from simulation agrees well with the numerical solution of the fourth order dispersion relation. Quasi-linear saturation of Buneman instability occurs when the ratio of electrostatic field energy density to initial electron drift kinetic energy density reaches up to a constant value, which, as predicted by Hirose [Plasma Phys. 20, 481 (1978)], is independent of initial electron drift velocity but varies with the electron to ion mass ratio (m/M) as ≈(m/M)1/3. This result stands verified in our simulations. The growth of the instability beyond the first saturation (quasilinear saturation) till its final saturation [Ishihara et al., PRL 44, 1404 (1980)] follows an algebraic scaling with time. In contrast to the quasilinear saturation, the ratio of final saturated electrostatic field energy density to initial kinetic energy density is relatively independent of the electron to ion mass ratio and is found from simulation to depend only on the initial drift velocity. Beyond the final saturation, electron phase space holes coupled to large amplitude ion solitary waves, a state known as coupled hole-soliton, have been identified in our simulations. The propagation characteristics (amplitude–speed relation) of these coherent modes, as measured from present simulation, are found to be consistent with the theory of Saeki et al. [PRL 80, 1224 (1998)]. Our studies thus represent the first extensive quantitative comparison between PIC simulation and the fluid/kinetic model of Buneman instability.
Heterogeneous nucleation on rough surfaces: Generalized Gibbs’ approach
Authors: Abyzov Alexander S. , Schmelzer Jürn W. P. , Davydov Leonid N.
Published: December 2017

Heterogeneous nucleation (condensation) of liquid droplets from vapor (gas) on a defective solid surface is considered. The vapor is described by the van der Waals equation of state. The dependence of nucleating droplet parameters on droplet size is accounted for within the generalized Gibbs approach. As a surface defect, a conic void is taken. This choice allows us to simplify the analysis and at the same time to follow the main aspects of the influence of the surface roughness on the nucleation process. Similar to condensation on ideal planar surfaces, the contact angle and catalytic factor for heterogeneous nucleation on a rough surface depend on the degree of vapor overcooling. In the case of droplet formation on a hydrophilic surface of a conic void, the nucleation rate considerably increases in comparison with the condensation on a planar interface. In fact, the presence of a defect on the hydrophilic surface leads to a considerable shift of the spinodal towards lower supersaturation in comparison with heterogeneous nucleation on a planar interface. With the decrease in the void cone angle, the heterogeneous spinodal approaches the binodal, and the region of metastability is diminished at the expense of the instability region.
Reliability analysis of InGaN/GaN multi-quantum-well solar cells under thermal stress
Authors: Huang Xuanqi , Fu Houqiang , Chen Hong , Lu Zhijian , Baranowski Izak , Montes Jossue , Yang Tsung-Han , Gunning Brendan P. , Koleske Dan , Zhao Yuji
Published: December 2017

We investigate the thermal stability of InGaN solar cells under thermal stress at elevated temperatures from 400 °C to 500 °C. High Resolution X-Ray Diffraction analysis reveals that material quality of InGaN/GaN did not degrade after thermal stress. The external quantum efficiency characteristics of solar cells were well-maintained at all temperatures, which demonstrates the thermal robustness of InGaN materials. Analysis of current density–voltage (J–V) curves shows that the degradation of conversion efficiency of solar cells is mainly caused by the decrease in open-circuit voltage (Voc), while short-circuit current (Jsc) and fill factor remain almost constant. The decrease in Voc after thermal stress is attributed to the compromised metal contacts. Transmission line method results further confirmed that p-type contacts became Schottky-like after thermal stress. The Arrhenius model was employed to estimate the failure lifetime of InGaN solar cells at different temperatures. These results suggest that while InGaN solar cells have high thermal stability, the degradation in the metal contact could be the major limiting factor for these devices under high temperature operation.
Transient anion spectra of the potential radiosensitizers 5-cyanateuracil and 5-thiocyanateuracil
Authors: Cornetta L. M. , Kossoski F. , Varella M. T. do N.
Published: December 2017

We report on the low energy anion spectra of 5-cyanateuracil (5-OCNU) and 5-thiocyanateouracil (5-SCNU), which have been the suggested potential radiosensitizers for use in cancer therapy [L. Chomicz et al., J. Phys. Chem. Lett. 4, 2853–2857 (2013)]. Employing bound state and scattering calculations, we obtained, for both molecules, a dipole bound state, a π* valence bound state, and four π* resonances, besides a σSCN* resonance for 5-SCNU. The cyanate and thiocyanate substituents give rise to additional long-lived π* resonances, compared to 5-halouracil radiosensitizers. From the reaction thresholds and the expected vibronic couplings among the anion states, efficient production of SCN and CN anions and radical fragments should be observed in dissociative electron attachment measurements for 5-SCNU. The corresponding dissociation processes in 5-OCNU are expected to be less effective in view of the lack of a long-lived σOCN* shape resonance and the little σ* admixture into the π* resonances located on the cyanate group. The present results thus indicate 5-SCNU as a more promising radiosensitizer at sub-excitation energies.
Chaos theory sheds new light on examining methods for determining electron wave functions
Authors: Liebendorfer Adam
Published: December 2017

Techniques like the Hartree-Fock method can elucidate electron wave functions but often struggle as electron orbitals become more complex. Approaching them as dynamical systems starts to explain why.
Achieving equity in Crunch&Sip®: a pilot intervention of supplementary free fruit and vegetables in NSW classrooms
Authors: Hector Debra , Edwards Shelley , Gale Joanne , Ryan Helen
Published: December 2017

Issue addressed

Anecdotal evidence from teachers in Western Sydney Local Health District (WSLHD) indicated that many primary school children are regularly unable to participate in the Crunch&Sip® (C&S) program (breaks during class time to eat fruit and/or vegetables and drink water) as they do not bring produce from home. Actual reach of the program may therefore be currently overestimated, and inequitable. This study examined the feasibility, acceptability and efficacy of providing school children supplementary, fresh free produce in supporting equitable participation in C&S.

Methods

Free fruit and vegetables were provided for 10 weeks to four schools in a socioeconomically‐disadvantaged area in Western Sydney. WSLHD sourced the produce at a discounted rate and storage and distribution was arranged in partnership with industry. Schools determined methods of allocation to children who did not have fruit or vegetables for the C&S break. Pre‐ and late‐intervention (Week 9) classroom surveys provided quantitative data of intervention efficacy. Qualitative methods were used with key school persons to explore barriers and enablers to implementation.

Results

Participation of children in C&S increased significantly from 46.7% pre‐intervention to 92.0% in Week 9. The proportion of children bringing fruit or vegetables from home also increased significantly, from 46.7% to 54.0%. Schools perceived the supplementary strategy to be highly feasible and acceptable.

Conclusion

Expansion of this equity strategy warrants consideration, although issues of sustainability would need to be addressed. The criteria for ‘full implementation’ should include high proportional participation by students in participating classes.

So what?

Establishing a system by which schools in disadvantaged areas can supplement their C&S program would effectively increase access to fruit and vegetables among those children most at need.
SCWISh network is essential for survival under mechanical pressure
Authors: Delarue Morgan , Poterewicz Gregory , Hoxha Ori , Choi Jessica , Yoo Wonjung , Kayser Jona , Holt Liam , Hallatschek Oskar
Published: December 2017

Significance

Growth in confined environments leads to the buildup of compressive mechanical stresses, which are relevant to diverse fields, from cancer to microbiology. In contrast to tensile stress, little is known about the molecular integration of compressive stresses. In this study, we elucidate the Ste11 through
Mucin/Sho1
, or SMuSh, pathway, which, together with the cell wall integrity pathway, is essential for viability of the budding yeast
Saccharomyces cerevisiae
when growing under mechanical pressure. Pressure sensing requires the transmembrane mucin, Msb2, which is linked to the actin cortex. Our result raises the intriguing question of whether mucins, widely conserved in eukaryotes and frequently misregulated in cancers, might sense compressive stresses in other organisms, including humans.
The effect of Ti addition on phase selection of CoCrCu0.5FeNi high-entropy alloys
Authors: Du W. D. , Liu N. , Peng Z. , Zhou P. J. , Xiang H. F. , Wang X. J.
Published: December 2017

With the increasing titanium, the volume fraction of face-centred cubic-structured dendrites decreased, and ordered B2 phase, σ, and Laves phase appeared in CoCrCu0.5FeNiTi x alloy when x > 0.5. With the increase of Ti content, Δ Smix, Δ Hmix, valence electron concentration (VEC), and Λ (=Δ Smix/ δ2) of CoCrCu0.5FeNiTi x alloys decreased, while atomic size difference ( δ) and electronegativity difference (Δ χ) increased. Topologically close-packed (TCP) structures are favoured when Δ Smix > 14.53 J K−1 mol−1. TCP phases can be found when δ > 5.05 and Δ χ ≥ 0.124. Simple solid solution phase is favoured when VEC ≥ 8.26 but multi-phases including TCP phase coexist when VEC < 8.26. Single-disordered solid solution forms only when Λ > 0.637, solid solution and TCP phases coexist when 0.531 < Λ < 0.637, and TCP phases are favoured when Λ < 0.531.
In vivo single cell analysis reveals Gata2 dynamics in cells transitioning to hematopoietic fate
Authors: Eich Christina , Arlt Jochen , Vink Chris S. , Solaimani Kartalaei Parham , Kaimakis Polynikis , Mariani Samanta A. , van der Linden Reinier , van Cappellen Wiggert A. , Dzierzak Elaine
Published: December 2017

Cell fate is established through coordinated gene expression programs in individual cells. Regulatory networks that include the Gata2 transcription factor play central roles in hematopoietic fate establishment. Although Gata2 is essential to the embryonic development and function of hematopoietic stem cells that form the adult hierarchy, little is known about the in vivo expression dynamics of Gata2 in single cells. Here, we examine Gata2 expression in single aortic cells as they establish hematopoietic fate in Gata2Venus mouse embryos. Time-lapse imaging reveals rapid pulsatile level changes in Gata2 reporter expression in cells undergoing endothelial-to-hematopoietic transition. Moreover, Gata2 reporter pulsatile expression is dramatically altered in Gata2+/− aortic cells, which undergo fewer transitions and are reduced in hematopoietic potential. Our novel finding of dynamic pulsatile expression of Gata2 suggests a highly unstable genetic state in single cells concomitant with their transition to hematopoietic fate. This reinforces the notion that threshold levels of Gata2 influence fate establishment and has implications for transcription factor–related hematologic dysfunctions.
Generic vanishing and minimal cohomology classes on abelian fivefolds
Authors: Casalaina-Martin Sebastian , Popa Mihnea , Schreieder Stefan
Published: December 2017

We classify

G
V

GV

-subschemes of five-dimensional ppavs, proving the main conjecture in a work by Pareschi and the second author in this case. This result is implied by a more general statement about subvarieties of minimal cohomology class whose sum is a theta divisor.
Culture, Relationship Norms, and Dual Entitlement
Authors: Chen Haipeng (Allan) , Bolton Lisa E , Ng Sharon , Lee Dongwon , Wang Dian
Published: December 2017

According to the dual entitlement principle, consumers find it fair for firms to price asymmetrically to cost changes—that is, for firms to increase prices when costs increase but maintain prices when costs decrease. However, a meta-analysis reveals asymmetric pricing is less prevalent in collectivistic (vs. individualistic) countries (study 1). We propose a fairness-based explanation, demonstrating that interdependent consumers in collectivistic cultures perceive asymmetric pricing to be less fair than do independent consumers in individualistic cultures (studies 2, 4, and 5). We attribute this cultural variation to culture-specific relationship norms. Specifically, we argue that while the practice of asymmetric pricing is consistent with the exchange norms among independent consumers that emphasize self-interest pursuit, it is inconsistent with the communal norms among interdependent consumers mandating firm benevolence. Supporting this argument, we find that (a) directly manipulating communal (vs. exchange) norms yields similar differences in fairness perceptions that mimic those due to culture (study 3), (b) the cultural differences are mediated by the communal mandate for firm benevolence (study 4), and (c) the cultural differences are mitigated when a firm frames asymmetric pricing as benevolent (study 5). We conclude by discussing the theoretical and managerial implications of these findings.
Acute Respiratory Distress Syndrome (ARDS)
Authors: Kreit John W.
Published: December 2017

Acute Respiratory Distress Syndrome reviews the definitions, causes, pathophysiology, and management of this relatively common, life-threatening disorder. This chapter describes how to ensure adequate tissue oxygen delivery while minimizing ventilator-induced lung injury and provides an in-depth review of how to determine the optimum level of positive end-expiratory pressure (PEEP). The first topic addressed is the precipitating factors and pathophysiology of acute respiratory distress syndrome. Next the chapter turns to mechanical ventilation, and covers the subjects of adequate oxygenation, ventilator-induced lung injury, ancillary therapies, ventilatory therapies, and high I:E ventilation. The topics addressed in the area of non-ventilatory therapies include: prone positioning of the patient, neuromuscular blockade, inhaled vasodilators, and extracorporeal membrane oxygenation (ECMO).
The Human Brain and its Epigenomes
Authors: Chess Andrew , Akbarian Schahram
Published: December 2017

Conventional psychopharmacology elicits an insufficient therapeutic response in more than one half of patients diagnosed with schizophrenia, bipolar disorder, depression, anxiety, or related disorders. This underscores the need to further explore the neurobiology and molecular pathology of mental disorders in order to develop novel treatment strategies of higher efficacy. One promising avenue of research is epigenetics.

Deeper understanding of genome organization and function in normal and diseased human brain will require comprehensive charting of neuronal and glial epigenomes. This includes DNA cytosine and adenine methylation, hundred(s) of residue-specific post-translational histone modifications and histone variants, transcription factor occupancies, and chromosomal conformations and loopings. Epigenome mappings provide an important avenue to assign function to many risk-associated DNA variants and mutations that do not affect protein-coding sequences. Powerful novel single cell technologies offer the opportunity to understand genome function in context of the vastly complex cellular heterogeneity and neuroanatomical diversity of the human brain.
Optogenetics and Related Technologies for Psychiatric Disease Research
Authors: Fenno Lief E. , Deisseroth Karl
Published: December 2017

Studying intact systems with simultaneous local precision and global scope is a fundamental challenge in biology. This familiar trade-off leads to important conceptual and experimental difficulties in psychiatric disease research and throughout the study of complex biological systems. Part of a solution may arise from optogenetics: the combination of genetic and optical methods to achieve gain- or loss-of-function of temporally defined events in specific cells embedded within intact living tissue or organisms. Such precise causal control within the functioning intact system can be achieved via introduction of genes that confer to cells both light-detection capability and specific effector function. A broad array of optogenetic tools and neuroscience applications have driven the wide adoption of optogenetics as a standard approach in neuroscience.