bluuebunny/crossref_metadata_2025 huggingface dataset:
SAH-Induced Electrophysiological Changes of Ventricular Myocytes and Role of N-acetylcysteine Protection
Authors: Yanardag Sirma , Ayaz Murat
Published: October 2018

Background Electrocardiogram (ECG) changes in patients with subarachnoid hemorrhage (SAH) are frequent. ST- and/or T-wave changes in ECG seem to predominate.

Study Aims To investigate the ion channel mechanisms of SAH-induced ventricular excitation-contraction coupling changes and the possible protective effect of N-acetylcysteine (NAC).

Methods Three groups of rabbits were used for the experiments. In two groups, SAH was induced by replacing the cerebrospinal fluid (CSF) with fresh autologous blood. In the control group, CSF was replaced with isotonic saline. In one SAH group, NAC was administered daily beginning at SAH induction. On day 5, ventricular action potentials, ionic currents, contractions, and intracellular free ion concentrations were recorded from the myocytes.

Results In the SAH group, no change was found in the sodium currents, but the transient outward potassium currents were depressed, rapid repolarizing currents were increased, and t-type calcium currents were increased. Contractions and the intracellular free calcium concentration were depressed. NAC treatment, in contrast, not only restores these electrical remodeling changes but also the contractile abnormalities in the cardiac myocytes.

Conclusion The changes in the action potential duration can be attributed to the measured ionic current changes. However, the exact mechanism, other than the oxidative stress, by which the NAC treatment protects the cardiac muscle needs additional investigations.
Can Freehand Elastosonography Be an Alternative to Renal Scintigraphy in Pediatric Vesicoureteral Reflux Cases?
Authors: Karabulut Bilge , Bayram Gulsah , Oztorun Can Ihsan , Ozcift Burak , Tiryaki Tuğrul Hüseyin
Published: October 2018

Introduction Detecting renal scar is important in pediatric patients with vesicoureteral reflux (VUR) for deciding on treatment option. The aim of this study is to detect whether freehand elastosonography technique could be an alternative to dimercaptosuccinic acid (DMSA) scan in determining renal scar formation.

Materials and Methods Between November 2015 and April 2016, 25 VUR patients, age ranging from 3 to 17 years admitted to our clinic, had urinary ultrasound and elastosonography, and data of approximately 147 renal region were recorded. Data were upper, middle, and lower pole renal parenchymal thickness and echogenicities obtained by ultrasound and these poles strain target (ST), strain reference (SR), and strain index (SI) values obtained by freehand elastosonography. DMSA scan data (differential function and upper, middle, and lower pole parenchymal scar formation) were recorded.

Results Scar formation and more than 10% reduction in differential function in renal scan were statistically higher in renal regions in which parenchymal thinning and echogenicity increase was detected by ultrasound. There was no elastosonographic data difference between renal units with and without differential function decrease. Also, there was no elastosonographic data difference between renal units with and without scar formation.

Conclusion In this study, we could not find any significant difference in term of tissue tension values (ST and SI) measured by freehand elastosonography between renal units with and without scar formation in renal scan.
Trial Characteristics That Affect Parental Consent in Neonatal Drug Trials
Authors: Hanvey I. Blaire , Aliaga Sofia , Laughon Matthew M. , Testoni Daniela , Smith P. Brian , Bauserman Melissa
Published: October 2018

Objective The main purpose of this article is to determine parental consent rates in neonatal drug trials and describe trial characteristics associated with higher rates.

Study Design We included neonatal drug trials published between 2009 and 2014 and compared parental consent rates among the following characteristics: phase type, gestational age, randomization type, drug administration route, drug dosing frequency, blood sampling, control type, length of study, funding source, and length of treatment. We compared characteristics using chi-square, Fisher's exact, one-way analysis of variance or Kruskal–Wallis tests.

Results We identified 52 trials: 38 trials (73%) reported data of parental consent. Median percentage (interquartile range) of parental consent was 79% (62, 89). Higher rates were observed in studies that used active comparators (87%) and shorter study lengths (81% for studies <24 hours).

Conclusion Parental consent rates for neonatal drug trials varied by study characteristics. Information on proportion of parents consented is valuable to assess generalizability of trial results and for preparing trial protocols.
Single versus Double-Balloon Transcervical Catheter for Labor Induction: A Systematic Review and Meta-Analysis
Authors: de los Reyes Samantha X. , Sheffield Jeanne S. , Eke Ahizechukwu C.
Published: October 2018

Objective To evaluate for difference in outcomes between single- and double-balloon catheters for labor induction.

Study Design We searched CINAHL, Embase, Cochrane Register, MEDLINE, ISI Web of Sciences, LILACs, and Google Scholar and retrieved studies through May 2017. Selection criteria included randomized controlled trials comparing single- versus double-balloon catheters. The primary outcome was time from catheter insertion to delivery. Heterogeneity of the results among studies was tested with the quantity I2
. For I2
values ≥50%, a random effects model was used to pool data across studies. Summary measures were reported as adjusted odds ratios (aORs) or as a mean difference (MD) with 95% confidence interval (CI).

Results Four trials including a total of 682 patients were included: 340 patients were randomized to induction with a single-balloon catheter and 342 to induction with a double-balloon catheter. There was no significant difference between groups with respect to time to delivery (18.8 vs. 19.6 hours; MD: 0.40; 95% CI: –1.56 to 0.76), vaginal delivery rate (65.3 vs. 62.3%; aOR: 1.04; 95% CI: 0.56–1.92), cesarean delivery rate (25.6 vs. 27.5%; aOR: 0.98; 95% CI: 0.55–1.73), or epidural use (58.4 vs. 62%; aOR: 0.81; 95% CI: 0.56–1.18).

Conclusion Double-balloon catheters have no apparent advantage over single-balloon catheters for labor induction.
Automating a Manual Sepsis Screening Tool in a Pediatric Emergency Department
Authors: Lloyd Julia , Ahrens Erin , Clark Donnie , Dachenhaus Terri , Nuss Kathryn
Published: October 2018

Objective This article describes the method of integrating a manual pediatric emergency department sepsis screening process into the electronic health record that leverages existing clinical documentation and keeps providers in their current, routine clinical workflows.

Methods Criteria in the manual pediatric emergency department sepsis screening tool were mapped to standard documentation routinely entered in the electronic health record. Data elements were extracted and scored from the medical history, medication record, vital signs, and physical assessments. Scores that met a predefined sepsis risk threshold triggered interruptive system alerts which notified emergency department staff to perform sepsis huddles and consider appropriate interventions. Statistical comparison of the new electronic tool to the manual process was completed by a two-tail paired t-test.

Results The performance of the pediatric electronic sepsis screening tool was evaluated by comparing flowsheet row documentation of the manual, sepsis alert process against the interruptive system alert instance of the electronic sepsis screening tool. In an 8-week testing period, the automated pediatric electronic sepsis screening tool identified 100% of patients flagged by the manual process (n = 29), on average, 68 minutes earlier.

Conclusion Integrating a manual sepsis screening tool into the electronic health record automated identification of pediatric sepsis screening in a busy emergency department. The electronic sepsis screening tool is as accurate as a manual process and would alert bedside clinicians significantly earlier in the emergency department course. Deployment of this electronic tool has the capability to improve timely sepsis detection and management of patients at risk for sepsis without requiring additional documentation by providers.
Risk of Neonatal and Infant Mortality in Twins and Singletons by Gestational Age
Authors: Chen Han-Yang , Chauhan Suneet P.
Published: October 2018

Objective To compare neonatal and infant mortality rates stratified by gestational age (GA) between singletons and twins and examine the three leading causes of death among them.

Study Design This was a retrospective cohort study using the U.S. vital statistics datasets. The study was restricted to nonanomalous live births at 24 to 40 weeks delivered in 2005 to 2014. We used multivariable Poisson regression models with robust error variance to examine the association between birth plurality (singleton vs. twin) and mortality outcomes within each GA, while adjusting for confounders. The results were presented as adjusted risk ratios (aRRs) with 95% confidence intervals (CIs).

Results Of 26,292,747 live births, 96.6% were singletons and 3.4% were twins. At 29 to 36 weeks of GA, compared with singletons, twins had a lower risk of neonatal mortality (aRR: 0.37–0.78) and infant mortality (aRR: 0.54–0.86). When examined by GA, the three leading causes of neonatal and infant mortality varied between singletons and twins.

Conclusion When stratified by GA, the risk of neonatal and infant mortality was lower at 29 to 36 weeks in twins than in singletons, though the cause of death varied.
Buccal versus Vaginal Misoprostol for Term Induction of Labor: A Retrospective Cohort Study
Authors: Dorr Meredith L. , Pierson Rebecca C. , Daggy Joanne , Quinney Sara K. , Haas David M.
Published: October 2018

Objective To compare the efficacy of similar buccal and vaginal misoprostol doses for induction of labor.

Study Design Retrospective chart review of 207 consecutive women undergoing term induction of labor with misoprostol. Misoprostol route and dosing were collected. Time to delivery and other labor outcomes (e.g., vaginal delivery less than 24 hours) were compared between women receiving buccal and vaginal misoprostol.

Results There was no significant difference in time to delivery for women receiving buccal (median 18.2 hour, 95% confidence interval [CI] = [14.9, 21.5]) versus vaginal (median 18.3 hour, 95% CI = [15.0, 20.4]) misoprostol (p = 0.428); even after adjusting for covariates (p = 0.381). Women who presented with premature rupture of membranes were more likely to receive buccal misoprostol (92.7% received buccal vs. 7.3% received vaginal, p < 0.001). A similar number of women delivered vaginally in the buccal group (88.2%) and vaginal misoprostol group (86.8%, p = 0.835). The proportion of women who experienced uterine tachysystole or chorioamnionitis did not significantly differ by route of administration.

Conclusion We found no significant differences in time to delivery or other labor outcomes between buccal or vaginal dosing of misoprostol in women undergoing labor induction at term.
Effects of Preeclampsia on Maternal and Pediatric Health at 11 Years Postpartum
Authors: Chan Stephanie E. , Pudwell Jessica , Smith Graeme N.
Published: October 2018

Objective To determine the association of preeclampsia (PE) with the presence of cardiovascular risk (CVR) factors at approximately 11 years postpartum and to assess the longer term effect of PE on childhood development.

Study Design A mail-out survey was sent to all women who were previously recruited into the Kingston arm of the Pre-Eclampsia New Emerging Team's prospective cohort (n = 112 PE and n = 150 control). Physical and biochemical CVR markers were compared between the two groups. Physical, social, and cognitive development of the children involved in the pregnancies was evaluated using the Vineland-3 Domain-Level Parent/Caregiver Form.

Results Thirteen PE women and 28 control women returned the study questionnaire. Based on the 2017 American Heart Association High Blood Pressure Clinical Practice Guidelines, 9/13 (69.2%) of the PE women, compared with 6/28 (21.4%) of the control women, have hypertension (p < 0.01). The median percentile rank for overall adaptive functioning was 58 (interquartile range [IQR: 21–73]) in the PE children and 81 (IQR: 61–94) in the control children (p < 0.05).

Conclusion The development of PE leads to longer term changes in CVR markers and in childhood development at approximately 11 years postpartum. Pregnancy and the postpartum provide an early window of opportunity for early maternal and child screening and intervention for health preservation and disease prevention.
The Effect of Early Active Mobilization on Union Rate after Ulnar Shortening Osteotomy
Authors: Saqib Rukhtam , Rooker Jemma , Baumann Andreas , Amirfeyz Rouin , Blackburn Julia
Published: October 2018

Background Ulnocarpal impaction occurs when there is excessive loading between the ulnar carpus and the distal ulna. Ulnar shortening osteotomies (USOs) decompress the ulnocarpal joint. Many studies have evaluated USO but none have considered the effect of early active mobilization on union rate.

Questions Does early active mobilization affect rate of union following USO? Does early active mobilization affect rate of complications following USO?

Patients and Methods We performed a retrospective review of 15 consecutive patients that underwent 16 USOs between 2011 and 2015. There were seven males and eight females. Median age at time of shortening osteotomy was 47 years (range: 11–63 years). The median time of the procedure was 62 minutes (range: 45–105 minutes) and the median change in ulnar variance was 5.5 mm (range: 0–10.5 mm). Six patients were initially immobilized in incomplete plaster casts postoperatively, while the remainder had only wool and crepe dressings. Early active mobilization commenced after the first postoperative visit at 12 days.

Results There was a 100% union rate in our series and 12 patients were pain-free at final follow-up. However, three of the patients with the longest times to union were smokers. Additionally, some patients may have achieved union between follow-up clinic visits.

Conclusion Early active mobilization after USO does not affect union rate. Prospective, randomized studies are required to investigate the effect of early active mobilization in light of factors known to increase time to union, such as smoking.

Level of Evidence This is a Level IV, case series.
A Rare Case of Pre-Existing Deep Venous Thrombosis in the Peroneal Vein of a Free Osteocutaneous Fibula Flap
Authors: Hayashi Satoshi , Kawamura Kenji , Maegawa Naoki , Nakanishi Akito , Mizutani Yasushi , Okuda Akinori , Kurata Shinpei , Shimizu Takamasa , Kira Tsutomu , Omokawa Shohei , Tanaka Yasuhito
Published: October 2018

Background Deep venous thrombosis (DVT) of the lower leg is a widespread medical problem and is associated with hypercoagulable states. Although spontaneous thrombosis of the peroneal vein of a fibula flap is theoretically possible, few cases of asymptomatic DVT of the peroneal vein encountered during fibula flap harvest have been reported.

Case Report A 45-year-old man presented with segmental bone defects of the tibia resulting from a fall. Treatment with a free vascularized osteocutaneous fibula flap from the contralateral lower leg was scheduled. Intraoperatively, diffuse thrombi were found in the peroneal venous system. After removal of thrombi, the fibula was grafted with anastomosis of the peroneal vessels to the recipient posterior tibial vessels. The skin paddle of the flap became congested after surgery; exsanguination of the skin paddle was performed with multiple skin incisions to relieve congestion. Despite treatment, the skin paddle became partially necrotic and additional skin grafting was performed. Bone union of the grafted fibula was achieved 5 months after initial surgery.

Conclusions To the best of our knowledge, only six cases of pre-existing DVT in the peroneal vein of a free osteocutaneous fibula flap have been reported. In three of these cases, the fibula flap was successfully grafted. Although successful free osteocutaneous fibula flap surgery might be possible in patients with peroneal venous thrombosis, careful preoperative evaluation is recommended for high-risk patients.
Regularity for evolution equations with non-autonomous perturbations in Banach spaces
Authors: Penz Markus
Published: October 2018

We provide regularity of solutions to a large class of evolution equations on Banach spaces where the generator is composed of a static principal part plus a non-autonomous perturbation. Regularity is examined with respect to the graph norm of the iterations of the principal part. The results are applied to the Schrödinger equation and conditions on a time-dependent scalar potential for the regularity of the solution in higher Sobolev spaces are derived.
Gaussian process based optimization of molecular geometries using statistically sampled energy surfaces from quantum Monte Carlo
Authors: Archibald R. , Krogel J. T. , Kent P. R. C.
Published: October 2018

Optimization of atomic coordinates and lattice parameters remains a significant challenge to the wide use of stochastic electronic structure methods such as quantum Monte Carlo (QMC). Measurements of the forces and stress tensor by these methods contain statistical errors, challenging conventional gradient-based numerical optimization methods that assume deterministic results. Additionally, forces are not yet available for some methods, wavefunctions, and basis sets and when available may be expensive to compute to sufficiently high statistical accuracy near energy minima, where the energy surfaces are flat. Here, we explore the use of Gaussian process based techniques to sample the energy surfaces and reduce sensitivity to the statistical nature of the problem. We utilize Latin hypercube sampling, with the number of sampled energy points scaling quadratically with the number of optimized parameters. We show these techniques may be successfully applied to systems consisting of tens of parameters, demonstrating QMC optimization of a benzene molecule starting from a randomly perturbed, broken symmetry geometry.
Properties of ALD TaxNy films as a barrier to aluminum in work function metal stacks
Authors: Dekkers H. F. W. , Ragnarsson L.-Å. , Schram T. , Horiguchi N.
Published: October 2018

Atomic layer deposited (ALD) tantalum nitride (TaxNy) is evaluated as a barrier against aluminum inside gate metal stacks of metal-oxide-semiconductor field effect transistor (MOSFET) devices. When deposited on hygroscopic oxides, like HfO2, amorphous tantalum nitride (a-TaxNy) is obtained, while deposition on Si or TiN results in polycrystalline Ta3N5. The low conductivity of both phases is not attractive for gate metal applications; however, a-TaxNy is crystallized to bixbyite Ta2N3 at 500 °C, improving its conductivity to ∼130 Ω−1 cm−1. For thicknesses below 10 nm, crystallization did not happen, but thin a-TaxNy barriers still obtain conductivity improvements to ∼500 Ω−1 cm−1 when Al diffuses into the film. In metal gate stacks, a-TaxNy screens the low work function of ALD TiAl more effectively than TiN. A barrier thickness reduction of 50% is achieved for n-MOSFET devices with an effective work function at 4.2–4.3 eV and low gate leakage. Slower diffusion of Al into TaxNy is observed by secondary ion mass spectroscopy; however, the cause of EWF lowering as a result of Al diffusion could not be confirmed. Instead, restoration of high EWF after removal of TiAl occurs, enabling an NMOS-first process integration with the use of 1 nm thin TaxNy barriers.
Spectral properties of complex networks
Authors: Sarkar Camellia , Jalan Sarika
Published: October 2018

This review presents an account of the major works done on spectra of adjacency matrices drawn on networks and the basic understanding attained so far. We have divided the review under three sections: (a) extremal eigenvalues, (b) bulk part of the spectrum, and (c) degenerate eigenvalues, based on the intrinsic properties of eigenvalues and the phenomena they capture. We have reviewed the works done for spectra of various popular model networks, such as the Erdős-Rényi random networks, scale-free networks, 1-d lattice, small-world networks, and various different real-world networks. Additionally, potential applications of spectral properties for natural processes have been reviewed.
Particle size effect of Ag catalyst for oxygen reduction reaction: Activity and stability
Authors: Chen Xin , Hu Rui , Sun Fanghua
Published: October 2018

Based on DFT calculations, we investigated the activity and the stability of three octahedral Ag nanoparticles (Ag19, Ag85, and Ag146) for catalytic oxygen reduction reaction (ORR) and further compared their ORR performance with an outspread flat Ag(111) surface and a Pt(111) surface. The results indicate that Ag19 cannot be used as an effective ORR catalyst mainly due to its poor stability in the electrochemical environment. In contrast, both Ag85 and Ag146 possess higher surface cohesive energies and cluster cohesive energies, indicating that they have relatively lower thermodynamic tendency to electrochemical dissolution. In addition, both of these two nanoparticles also have high catalytic activities, as suggested by the calculated highest potentials of 0.80 and 0.76 V. Therefore, our current study indicates that an octahedral Ag nanoparticle with the diameter of ∼2 nm should have good catalytic activity and stability for ORR.
Long-time dynamics for nonlinear porous thermoelasticity with second sound and delay
Authors: Aouadi Moncef
Published: October 2018

This paper is concerned with the long-time behavior of a damped porous thermoelastic problem. It has been studied by many authors and most of the known results are concerned with decay issues under different boundary conditions and damping terms. There are just a few references on the long-time dynamics of such systems. The purpose of the present work is to complement and extend some early studies on porous thermoelastic systems by establishing new results on the existence of attractors and some of their properties. Motivated by this scenario, we consider a one-dimensional porous thermoelastic system with linear frictional damping, nonlinear source terms, and a time-varying delay term in the internal feedback, where the heat flux depends on Cattaneo’ law. Under some suitable assumptions on the weights of feedback, we establish the global well-posedness of the system by using the C0−semigroup theory of linear operators. Then we show the existence of a global attractor for finite energy solutions and we prove its smoothness and finite fractal dimension. Furthermore, the existence of a generalized fractal exponential attractor is also derived.
Integral invariants and decay of temporally developing grid turbulence
Authors: Watanabe T. , Nagata K.
Published: October 2018

We present a study of a large-scale energy spectrum and integral invariants in temporally developing grid turbulence at mesh Reynolds numbers of ReM = 10 000 and 20 000 by employing direct numerical simulations (DNSs) in a periodic box. The simulations are initialized with a velocity field that approximates the wakes induced by the bars of conventional square grids. The turbulence statistics obtained in the temporal DNS agree well with those of the previous experiments in both the production and decay regions. The temporally developing grid turbulence also has a so-called non-equilibrium region, which is consistent with its spatially developing counterpart, where the normalized dissipation rate of turbulence kinetic energy (TKE), Cε, increases as the turbulence decays. The decay exponent n of TKE is n = 1.22 at ReM = 20 000 and n = 1.35 at ReM = 10 000, which are close to the values for the Saffman turbulence [i.e., 6/5 for ReM = 20 000 and 6(1 + p)/5 ≈ 1.36 for ReM = 10 000 with p ≈ 0.13 obtained by Cε ∼ tp at large t]. The longitudinal integral length scale and the TKE dissipation rate also exhibit temporal evolutions consistent with the Saffman turbulence for both ReM. The Saffman integral directly evaluated in the grid turbulence tends to be time-independent after the turbulence evolves for about 200 times of characteristic time scale defined by mesh size divided by the mean velocity of a fluid passing the grid. A direct evaluation of the TKE spectrum E(k) shows that E(k) ≈ Lk2/4π2 is valid for a finite range of low wavenumbers.
Substantial magnetoelectric coupling in nanocrystalline-Fe2TeO6 at room temperature
Authors: Pal P. , Sahoo Aditi , Abdullah Md. F. , Kaushik S. D. , Vishwakarma P. N. , Singh A. K.
Published: October 2018

Nanocrystalline Fe2TeO6 (FTO) is synthesized following the sol-gel process. The nanoaspect of FTO is confirmed from transmission electron microscopy, where the particles of sizes 10–40 nm are seen. Magnetic measurement on nano-FTO confirms the antiferromagnetic nature of particles having Nèel temperature TN = 167 K, which is very much lower than that of bulk (210 K). Polarization verses electric field loop measurement at room temperature (RT) gives the remanent polarization (Pr) value of 0.098 μC/cm2, confirming ferroelectricity in FTO. A nonmonotonous increase in the remanent polarization is noticed when an external magnetic field is applied on the sample. This is a clear indication of prevailing substantial magnetoelectric (ME) coupling in the sample at room temperature. The quantification of magnetoelectricity is done by directly measuring the ME voltage (V) in the presence of varying dc magnetic field (H), and the ME coefficients are obtained using a quadratic relation in H. The values so obtained for the first order (α/d), second order (β/d), and third order (γ/d) ME coefficients are ∼0.22 mV cm−1Oe−1, ∼−1.70 × 10−2 mV cm−1 Oe−2, and ∼0.72 × 10−6 mV cm−1 Oe−3, respectively. The presence of ferroelectricity and magnetoelectricity above the Nèel temperature is a very unusual phenomenon in this material. The presence of short range magnetic ordering which prevails even up to RT, much higher than that of long range magnetic ordering temperature, is suspected to be responsible for this.
Inference of time-varying networks through transfer entropy, the case of a Boolean network model
Authors: Porfiri Maurizio , Ruiz Marín Manuel
Published: October 2018

Inferring network topologies from the time series of individual units is of paramount importance in the study of biological and social networks. Despite considerable progress, our success in network inference is largely limited to static networks and autonomous node dynamics, which are often inadequate to describe complex systems. Here, we explore the possibility of reconstructing time-varying weighted topologies through the information-theoretic notion of transfer entropy. We focus on a Boolean network model in which the weight of the links and the spontaneous activity periodically vary in time. For slowly-varying dynamics, we establish closed-form expressions for the stationary periodic distribution and transfer entropy between each pair of nodes. Our results indicate that the instantaneous weight of each link is mapped into a corresponding transfer entropy value, thereby affording the possibility of pinpointing the dominant weights at each time. However, comparing transfer entropy readings at different times may provide erroneous estimates of the strength of the links in time, due to a counterintuitive modulation of the information flow by the non-autonomous dynamics. In fact, this time variation should be used to scale transfer entropy values toward the correct inference of the time evolution of the network weights. This study constitutes a necessary step toward a mathematically-principled use of transfer entropy to reconstruct time-varying networks.
On the unsteadiness of shock–laminar boundary layer interactions of hypersonic flows over a double cone
Authors: Tumuklu Ozgur , Theofilis Vassilis , Levin Deborah A.
Published: October 2018

Unsteadiness of axisymmetric shock-dominated hypersonic laminar separated flow over a double cone is studied for the first time using a combination of time accurate Direct Simulation Monte Carlo (DSMC) calculations, linear global instability analysis, and momentum potential theory (MPT). Close to steady state linear analysis reveals the spatial structure of the underlying temporally stable global modes. At all Reynolds numbers examined, the amplitude functions demonstrate the strong coupling between the separated flow region at the cone junction with the entire shock system, including pressure and temperature waves generated behind the shock and spatially amplified Kelvin-Helmholtz waves. In addition, as the Reynolds number is increased, temporally damped harmonic shock oscillations and multiple-reflected λ-shock patterns emerge in the eigenfunctions. Application of the MPT (valid for both linear and nonlinear signals) to the highest Reynolds number DSMC results shows that large acoustic and thermal potential variations exist in the vicinity of the separation shock, the λ-shock patterns, and the shear layers. It is further shown that the motion of the bow shock system is highly affected by non-uniformities in the acoustic field. At the highest Reynolds number considered here, the unsteadiness is characterized by Strouhal numbers in the shear layer and bow-shock regions and is found to be in qualitative agreement with earlier experimental and numerical work.
Surface recombination in the direct simulation Monte Carlo method
Authors: Molchanova Alexandra N. , Kashkovsky Alexander V. , Bondar Yevgeniy A.
Published: October 2018

This work is aimed at the development of surface chemistry models for the Direct Simulation Monte Carlo (DSMC) method applicable to non-equilibrium high-temperature flows about reentry vehicles. Probabilities of adsorption and Eley-Rideal recombination dependent on individual properties of each particular molecule and frequencies of desorption and Langmuir-Hinshelwood recombination are determined from macroscopic reaction rate data. Various macroscopic finite-rate surface reaction sets are used for the construction of the DSMC surface recombination models for the reaction cured glass and α-alumina surfaces. The models are implemented in the SMILE++ software system for DSMC computations, and detailed verification of the code is performed. The proposed approach is used to study the effects of surface recombination on the aerothermodynamics of a blunt body at high-altitude reentry conditions.
Impact of three-dimensional hot-spot flow asymmetry on ion-temperature measurements in inertial confinement fusion experiments
Authors: Woo K. M. , Betti R. , Shvarts D. , Mannion O. M. , Patel D. , Goncharov V. N. , Anderson K. S. , Radha P. B. , Knauer J. P. , Bose A. , Gopalaswamy V. , Christopherson A. R. , Campbell E. M. , Sanz J. , Aluie H.
Published: October 2018

Three-dimensional (3-D) implosion asymmetries lead to significant variations in ion-temperature measurements in inertial confinement fusion experiments. We present an analytical method to generalize the physical properties of velocity variance in the Brysk ion-temperature model. This analysis provides a consistent explanation for the 3-D effects of inferred ion-temperature variations for various single modes and multimodes modeled by the deceleration-phase hydrocode DEC3D and the neutron transport code IRIS3D. The effect of the hot-spot flow asymmetry on variations in ion-temperature measurements is shown to be uniquely determined by a complete set of six hot-spot flow parameters. An approximated solution to the minimum inferred ion temperature is derived and shown to be close to the thermal ion temperature for low mode ℓ = 1, which exhibits the largest anisotropic velocity variance in the single-mode spectrum. The isotropic velocity variance for low mode ℓ = 2 is shown to result in the minimum inferred ion temperatures being well above the thermal ion temperature.
Direct measurement of microscale flow structures induced by inertial focusing of single particle and particle trains in a confined microchannel
Authors: Pan Zhenhai , Zhang Runlin , Yuan Chen , Wu Huiying
Published: October 2018

Understanding the flow structures induced by inertial focusing of particles is essential in microfluidics-based applications. In spite of numerous studies described in the literature, such microscale flows have, until today, not been subject to quantitative experimental study. This paper describes the construction and validation of a micro-particle image velocimetry-based experimental setup to investigate particle-induced flows in a confined microchannel. The flow structures around a single inertially focused particle are first visualized and quantitatively measured at Reynolds numbers Re from 21 to 525. A ring-like vortex flow is observed to form in front of the particle at Re = 63 owing to an increased particle lag effect, and finally the reverse flow regime is replaced by a vortex flow regime (at Re ≥ 105). This vortex flow produces a strong wall repulsive force and pushes the equilibrium position of the particle toward the channel center. Then, flows induced by both in-line and staggered particle trains are investigated (for 21 ≤ Re ≤ 105). For in-line particle trains, single-vortex flows are present between two neighboring particles on both sides of the channel. For staggered particle trains, two vortices rather than one are present between two neighboring particles at small Re (Re = 21), but this double-vortex flow develops into a single-vortex flow at relatively high Re (Re = 105). The present investigation helps in understanding particle dynamics and the mechanisms of interaction among particles, fluid, and channel walls. The experimental results presented here also provide validation data for further numerical and analytical studies.
The energy flow and mechanical modeling of soft chemo-mechanical machines
Authors: Chen Liyuan , Xue Yaoting , Chen Weijia , Zhang Mingqi , Chen Xiangping , Cao Xunuo , Zhang Zhen , Li Guorui , Li Tiefeng
Published: October 2018

Soft chemo-mechanical (SCM) machines convert chemical energy into mechanical energy. They have the advantages of fast actuation and compliant deformation and possess wide applications in soft robots and flexible smart devices. Using experiments and theoretical modeling, this paper investigates the chemo-mechanical energy flows and the energy conversion cycle in the pressure and volume (P–V) plane of an SCM machine consisting of a soft membrane and cylindrical chambers. The machine generates 16.1 mJ of mechanical energy per cycle. We study heat dissipation as the key issue affecting the conversion efficiency. The states of the conversion cycle calculated from mechanical modeling fit well with those measured experimentally. The design principles and the theoretical methods can be used to guide the fabrication and characterization of SCM actuators and robots.
The reduction of magnetic reconnection outflow jets to sub-Alfvénic speeds
Authors: Haggerty Colby C. , Shay Michael A. , Chasapis Alexandros , Phan Tai D. , Drake James F. , Malakit Kittipat , Cassak Paul A. , Kieokaew Rungployphan
Published: October 2018

The outflow velocity of jets produced by collisionless magnetic reconnection is shown to be reduced by the ion exhaust temperature in fully kinetic particle in cell simulations and in situ satellite observations. We derive a scaling relationship for the outflow velocity based on the upstream Alfvén speed and the parallel ion exhaust temperature, which is verified in kinetic simulations and observations. The outflow speed reduction is shown to be due to the firehose instability criterion, and so, for large enough guide fields, this effect is suppressed and the outflow speed reaches the upstream Alfvén speed based on the reconnecting component of the magnetic field.
Oscillations in the mean transition time of a particle scattered on a double slit potential
Authors: Ianconescu Reuven , Pollak Eli
Published: October 2018

Scattering through a double slit potential is one of the most fundamental problems in quantum mechanics. It is well understood that due to the superposition of amplitudes, one observes a spatial interference pattern in the scattered wavefunction reflecting the superposition of amplitudes coming from both slits. However, the effect of the double slit on the mean time it takes to traverse the slit has not been considered previously. Using a transition path time formalism, we show that when a single Gaussian wavepacket is scattered through a double slit potential, one finds not only oscillations in the scattered density resulting from the spatial interference created by the splitting of the wavepacket but also an oscillatory pattern in the mean scattering time. Long times are associated with low values of a suitably defined momentum, and short times with higher values. The double slit thus serves as a momentum filtering device. We also find an interference pattern in the time averaged momentum weak value profile of the scattered particle implying that the double slit also acts as a weak momentum filter. These results not only demonstrate the value of considering transition path time distributions in their quantum mechanical context but also present a challenge to semiclassical approximations—can they account for temporal interference?
One-particle density matrix polarization susceptibility tensors
Authors: Błasiak Bartosz
Published: October 2018

The electric field-induced change in the one-electron density has been expressed as a series of the one-particle density matrix susceptibilities interacting with the spatial distribution of the electric field. The analytic approximate expressions are derived at the Hartree-Fock theory, which serves as a basis for the construction of the generalized model that is designed for an arbitrary form of wavefunction and any type of one-particle density matrix. It is shown that it is possible to accurately predict the changes in the one-electron ground-state density of water molecule in a spatially uniform electric field, as well as in spatially non-uniform electric field distribution generated by point charges. When both linear and quadratic terms with respect to the electric field are accounted for, the electric field-induced polarization energies, dipole moments, and quadrupole moments are quantitatively described by the present theory in electric fields ranging from weak to very strong (0.001–0.07 a.u.). It is believed that the proposed model could open new routes in quantum chemistry for fast and efficient calculations of molecular properties in condensed phases.
One- and two-dimensional electrodynamic steering of electrospun polymer nanofibers
Authors: Kyselica Rudolf , Enikov Eniko T. , Anton Rein
Published: October 2018

Polymer nanofibers, with their specific set of material properties, are favorable for many applications in biomedical engineering (scaffold, stent, or tissue engineering). This application, however, requires the ability to control the manufacturing process together with organization and orientation of the deposited fiber. Electrospinning device parameters leading to a stable fiber extrusion were already found, together with the influence of the individual working parameters on the fiber properties. It was also found that fiber steering via the external electrostatic field, created by auxiliary electrodes, has very limited steering capabilities. In this article, electrodynamic steering of the electrospun polymer nanofiber is discussed, with focus on the macroscopic fiber deposition pattern and microscopic fiber alignment and straightness. Different electric field distributions are examined, and the corresponding fiber collection patterns are demonstrated on a series of experiments. Finally, a mathematical model of a discretized fiber is created. Matching the simulation and experimental results allows for the determination of unknown fiber properties, like the structural damping coefficient or Stokes drag coefficient.
Energy storage properties in BaTiO3-Bi3.25La0.75Ti3O12 thin films
Authors: Yang B. B. , Guo M. Y. , Song D. P. , Tang X. W. , Wei R. H. , Hu L. , Yang J. , Song W. H. , Dai J. M. , Lou X. J. , Zhu X. B. , Sun Y. P.
Published: October 2018

Developing lead-free film dielectric capacitors with high-performance of energy storage density, efficiency, fatigue endurance, and thermal stabilities is desirable. Here, we report energy storage properties in (1-x)BaTiO3-xBi3.25La0.75Ti3O12 thin films. It is revealed that a 0.6BaTiO3-0.4Bi3.25La0.75Ti3O12 thin film with a thickness of 280 nm and a crystallization temperature of 650 °C shows a breakdown strength of 3.23 MV/cm with a large polarization value and dielectric constant. An ultrahigh energy storage density of 61.1 J/cm3 and an efficiency of 84.2% are simultaneously achieved at room temperature. Additionally, excellent fatigue endurance after 6 × 109 cycles and good thermal stability up to 150 °C are observed, implying excellent energy storage performance in 0.6BaTiO3-0.4Bi3.25La0.75Ti3O12 thin films.
Thermal expansion of single-crystalline β-Ga2O3 from RT to 1200 K studied by synchrotron-based high resolution x-ray diffraction
Authors: Cheng Zongzhe , Hanke Michael , Galazka Zbigniew , Trampert Achim
Published: October 2018

The anisotropic coefficient of thermal expansion for single-crystalline monoclinic β-Ga2O3 has been precisely measured by synchrotron-based high resolution x-ray diffraction in the temperature range from 298 to 1200 K. We derived values along the three main crystallographic directions, based on spacings for (600), (020), and (2¯04) lattice planes. αa changes non-linearly between 0.10 × 10–6 K–1 and 2.78 × 10–6 K–1 in the temperature range of 298 to 1200 K, while the values of αb and αc along the further two directions are nearly double. Within the Einstein model, we have numerically modeled the functional dependencies applying a single phonon mode.
High-sensitivity strain sensor with an in-fiber air-bubble Fabry-Perot interferometer
Authors: Zhou Kun , Ai Ming-Zhong , Qian Zhong-Hua , Gao Xin-Xia , Hu Zhi-Hao , Li Qiang , Yuan Long , Wang Zhao , Huang Yun-Feng , Tu Tao , Cui Jin-Ming , Li Chuan-Feng , Guo Guang-Can
Published: October 2018

We present a laser machining method for fabricating an all-fiber pillar-in-bubble Fabry-Perot interferometer (FPI), which is used for strain sensors with high sensitivity. The micro-structure of the air-bubble is fully controllable, especially the cavity length and sidewall thickness. The measured sensitivity of this strain sensor is as high as 56.69 pm/με, which is several times higher than that of most FPI strain sensors reported to date. This sensor also has a low-temperature sensitivity of 0.682 pm/°C, reducing the cross-sensitivity between tensile strain and temperature to 0.012 με/°C. Furthermore, such a sensor has the benefits of flexible design, simple fabrication, and high reproducibility, making it attractive for practical applications.
Promoter of the wheat lipid transfer protein, TdLTP4, drives leaf-preferential expression in transgenic Arabidopsis plants
Authors: Safi Héla , Belgaroui Nebras , Masmoudi Khaled , Brini Faiçal
Published: October 2018

In a previous report, a gene encoding a durum wheat lipid transfer protein, TdLTP4, was characterised as induced by abiotic and biotic stresses. In the present work, we investigated the regulation of the gene TdLTP4. A TdLTP4 promoter (PrTdLTP4) region of around 868-bp was isolated and sequenced. Its analysis revealed the presence of several DNA boxes known to be important mainly in the regulation of genes expressed under abiotic stress (salt and dehydration), abscisic acid (ABA) and pathogen responsiveness. The whole PrTdLTP4 fragment was fused to the reporter gene β-glucuronidase (gusA) and analysed in transgenic Arabidopsis plants. Histochemical assays of transgenic Arabidopsis plants showed that the 868-bp fragment of TdLTP4 gene promoter was found to be sufficient for both spatial and temporal patterns of its expression. Under control conditions, GUS histochemical staining was observed significantly only in young leaves of 8- and 12-day-old plants. Whereas after stress challenge especially with NaCl and mannitol, GUS transcripts expression increased substantially in leaves of 30-day-old transgenic seedlings. Real-time qPCR expression analysis of the gusA gene, confirmed the results of histochemical assays. Taken together these data provide evidence that PrTdLTP4 functions as abiotic-stress-inducible promoter in a heterologous dicot system and could be an excellent tool for future crop improvement.
Modulation of NKG2D, NKp46, and Ly49C/I facilitates natural killer cell-mediated control of lung cancer
Authors: Shi Lei , Li Kang , Guo Yizhan , Banerjee Anirban , Wang Qing , Lorenz Ulrike M. , Parlak Mahmut , Sullivan Lucy C. , Onyema Oscar Okwudiri , Arefanian Saeed , Stelow Edward B. , Brautigan David L. , Bullock Timothy N. J. , Brown Michael G. , Krupnick Alexander Sasha
Published: October 2018

Significance

Lung cancer is unique among solid tumors as robust natural killer (NK) cell function correlates with resistance to disease. Here we describe that NK cell education by major histocompatibility class I (MHCI) leads to the up-regulation of NKG2D- and NKp46-activating receptors that recognize lung cancer. We further demonstrate that upon activation NK cells down-regulate the expression of the Ly49C/I inhibitory receptor, thus eliminating target interference by MHCI. Our findings are significant based on the demonstration that NK cells that arise in an MHCI
+/+
environment present a substantial barrier to the growth of lung cancer, and expression of both activating and inhibitory receptors is not fixed but varies based on environmental context.
p53 mutants cooperate with HIF-1 in transcriptional regulation of extracellular matrix components to promote tumor progression
Authors: Amelio Ivano , Mancini Mara , Petrova Varvara , Cairns Rob A. , Vikhreva Polina , Nicolai Sara , Marini Alberto , Antonov Alexey A. , Le Quesne John , Baena Acevedo Juvenal D. , Dudek Kate , Sozzi Gabriella , Pastorino Ugo , Knight Richard A. , Mak Tak W. , Melino Gerry
Published: October 2018

Significance

Expression in cancer cells of novel proteins generated by mutations in the
TP53
gene is an important prognostic factor; however, how p53 mutants promote cancer progression is largely unknown. Here, we describe a molecular mechanism of gain-of-function by mutant p53 in hypoxic non-small cell lung cancer (NSCLC) cells. We identified the existence of a hypoxia-inducible factor-1 (HIF-1)/mutant p53 complex, exerting transcriptional control of a specific subset of protumorigenic genes, codifying for extracellular matrix (ECM) components. Employing in vivo cancer models and analyzing clinical material, we demonstrate that these ECM components substantially contribute to the synergistic protumorigenic activity of p53 mutants and HIF-1. Our data indicate that HIF-1/mutant p53 cross-talk is an innovative potential therapeutic target to treat advanced NSCLC.