bluuebunny/crossref_metadata_2025 huggingface dataset:
Penetrating Foreign Bodies in Head and Neck Trauma: A Surgical Challenge
Authors: Voss JanOliver , Thieme Nadine , Doll Christian , Hartwig Stefan , Adolphs Nicolai , Heiland Max , Raguse Jan-Dirk
Published: April 2018

Penetrating foreign bodies of different origins in the head and neck are rare and potentially dangerous injuries, which might pose problems for their detection, primary care, and final treatment. Depending on the severity of the underlying trauma, some injuries present a higher risk for the presence of foreign bodies. Minor wounds, including common lacerations, are likely to be contaminated with loose gravel debris or dental fragments, and need to be distinguished from severe wounds caused by impalement, shootings, stabbings, and explosions. Blast injuries resulting from terror attacks are challenging recent therapeutic concepts. Even though these injury patterns are uncommon, they carry the risk of impacted objects with dramatic consequences. Despite improving medical imaging techniques, detection remains a challenge as it is dependent on the material of the foreign body, the affected anatomical site, and the injury severity. Therefore, a detailed history of the circumstances leading to trauma is essential when foreign objects are not visible during clinical examination. Precise detection of the foreign body, its anatomical position, and the affected surrounding structures are vital, especially for impalement injuries of the head and neck area. Therefore, an interdisciplinary planning approach is essential prior to removal of the foreign object. Finally, tension-free anatomical adaptation of the corresponding structures is crucial for maintaining and restoring aesthetic and function. Here, we give an overview of the diagnosis and treatment of cases of foreign body injuries encountered in our department.
Peripartum Morbidity after Cesarean Delivery for Arrest of Dilation at 4 to 5 cm Compared with 6 to 10 cm
Authors: Sperling Jeffrey , Has Phinnara , Lovgren Todd , Connealy Brendan , Rouse Dwight , Dahlke Joshua
Published: April 2018

Objective Given that recent consensus guidelines established to decrease cesarean delivery (CD) rates use 6 cm to define the onset of the active phase of labor, our objective was to evaluate maternal and neonatal outcomes after CD for the indication of arrest of dilation at 4 to 5 cm compared with ≥ 6 cm.

Study Design We performed a secondary analysis using data from the Maternal Fetal-Medicine Units Network Cesarean Registry. We included nulliparous women with term, singleton, vertex gestations who underwent primary CD for arrest of dilation. We compared those who reached a maximum cervical dilation of 4 to 5 cm with those of ≥6 cm. Our primary outcome was composite maternal morbidity that included chorioamnionitis, endometritis, transfusion, wound complication, operative injury, intensive care unit admission, or death.

Results Of the 73,257 women in the dataset, 5,681 met the inclusion criteria. After adjusting for confounders, there was no difference in composite maternal (adjusted odds ratio [aOR]: 1.19; 95% confidence interval [CI]: 0.94–1.52) or neonatal morbidity (aOR: 0.94; 95% CI: 0.79–1.10) between the groups.

Conclusion In this historical cohort, maternal and neonatal outcomes after CD for arrest of dilation ≥ 6 cm were comparable to those performed at 4 to 5 cm and support recent labor management guidelines.
A Prospective Evaluation of Health-Related Quality of Life following Lymphaticovenular Anastomosis for Upper and Lower Extremities Lymphedema
Authors: Salgarello Marzia , Mangialardi Maria , Pino Valentina , Gentileschi Stefano , Visconti Giuseppe
Published: April 2018

Background Lymphedema is a progressive disease that negatively affects body image and physical, psychological, and social functions. There is lack of evidence in the present literature about the impact of super microsurgical lymphaticovenular anastomosis (LVA) on health-related quality of life (HRQoL). The aim of this prospective study is to report the outcomes of patients' HRQoL after LVA for lower and upper extremities lymphedema.

Methods Between September 2015 and February 2017, 74 patients with upper or lower limb lymphedema (ULL or LLL) underwent LVA at our center. Quality of life (QoL) was assessed by lymphedema QoL questionnaire (LyMQoL), which is a validated disease-specific instrument to measure the impact of lymphedema on patient's lives, covering four domains: function, body image, symptoms, and mood. All patients were evaluated preoperatively, 1 month after surgery, and every 3 months up to 1 year. Additionally, we evaluated the episodes of lymphangitis and the need for conservative therapy before and after surgery.

Results After a mean follow-up of 8.5 months (range: 2–21 months), we observed an increase of 2.3 points in the overall QoL average for upper limb and 2.6 points for lower limb (p  <  0.001). A statistically significant improvement in all four domains (p  <  0.01) was reported after surgery, being present from the first postoperative months for both upper and lower extremities.

Conclusion Our study shows that lymphaticovenular anastomosis improves HRQoL in patients affected by ULL and LLL. Additionally, both a reduction of episodes of lymphangitis and a decrease in the need of conservative therapy were observed in this cohort of patients.
Normal Cervical Effacement in Term Labor
Authors: Stout Molly , Woolfolk Candice , Tuuli Methodius , Macones George , Cahill Alison , Rhoades Janine
Published: April 2018

Objective To estimate the natural history of cervical effacement in labor.

Study Design This is a retrospective cohort study of term, vertex, singletons who reached 10 cm of cervical dilation from 2010 to 2014. Interval-censored regression was used to estimate the median number of hours between changes in effacement (measured in centimeters of the residual cervix) and to estimate the median effacement at a given cervical dilation. Analysis was stratified by parity and labor type.

Results In total, 7,319 patients were included. Multiparas had faster effacement from 1 cm to complete effacement than nulliparas, but nulliparas were significantly more effaced at each cervical dilation. Patients in spontaneous labor had faster effacement and were significantly more effaced at each centimeter of cervical dilation than those who were induced or augmented. Once active labor was established (>6 cm of cervical dilation), 95% of patients had an effacement of 1 cm or less. By 8 cm of cervical dilation, 50% of all patients were completely effaced.

Conclusion There is a wide range in the normal length of time for the progression of cervical effacement. However, once a patient is in active labor, 95% of patients have effaced to 1 cm or less.
Extended interaction oversized coaxial relativistic klystron amplifier with gigawatt-level output at Ka band
Authors: Li Shifeng , Duan Zhaoyun , Huang Hua , Liu Zhenbang , He Hu , Wang Fei , Wang Zhanliang , Gong Yubin
Published: April 2018

In this paper, an extended interaction oversized coaxial relativistic klystron amplifier (EIOC-RKA) with Gigawatt-level output at Ka band is proposed. We introduce the oversized coaxial and multi-gap resonant cavities to increase the power capacity and investigate a non-uniform extended interaction output cavity to improve the electronic efficiency of the EIOC-RKA. We develop a high order mode gap in the input and output cavities to easily design and fabricate the input and output couplers. Meanwhile, we design the EIOC-RKA by using the particle-in-cell simulation. In the simulations, we use an electron beam with a current of 6 kA and a voltage of 525 kV, which is focused by a low focusing magnetic flux intensity of 0.5 T. The simulation results demonstrate that the saturated output power is 1.17 GW, the electronic efficiency is 37.1%, and the saturated gain is 57 dB at 30 GHz. The self-oscillation is suppressed by adopting the absorbing materials. The proposed EIOC-RKA has plenty of advantages such as large power capacity, high electronic efficiency, low focusing magnetic, high gain, and simple structure.
Ultra-fast AC electro-osmotic micropump with arrays of asymmetric ring electrode pairs in 3D cylindrical microchannel
Authors: Gao Xiaobo , Li Yu Xiao
Published: April 2018

AC electro-osmotic (ACEO) micropumps presently involve the planar or nonplanar electrode pair array in the rectangular microchannel. However, this paper presented a theoretical model of an ultra-fast 3D ring ACEO micropump with arrays of asymmetric ring electrode pairs in the cylindrical microchannel. The theory is on the basis of the interaction between the nonuniform electric field and ions of an electric double layer (EDL) on the surface of ring electrodes. Therefore, we first established the equivalent hollow cylinder capacitance of EDL for ring ACEO micropumps. Then, the 3D Poisson-Boltzmann model by solving the electric field and fluidic flow field with the charge conservation and the slip velocity boundary conditions was numerically calculated. For a dilute strong electrolyte solution, the conductivity as a function of the electrolyte concentration can be obtained by the modified Kohlrausch's dilution empirical equation with the molar conductivity. The results revealed that the flow rate of ring ACEO was higher than the planar ACEO, which agreed well with the experiment. The dependences of the time-averaged pumping velocity on the frequency and concentration have similar bell profiles with a maximal value. Moreover, the optimal velocity with proper geometric parameters was obtained at a given frequency, voltage, concentration, and radius. The high-speed ring ACEO micropump will be significant for the experimental studies to further improve the flow rate and be hopeful for applications of microfluidic mixing, particle manipulation, and so on.
Excited state non-adiabatic dynamics of the smallest polyene, trans 1,3-butadiene. I. Time-resolved photoelectron-photoion coincidence spectroscopy
Authors: Boguslavskiy Andrey E. , Schalk Oliver , Gador Niklas , Glover William J. , Mori Toshifumi , Schultz Thomas , Schuurman Michael S. , Martínez Todd J. , Stolow Albert
Published: April 2018

The ultrafast excited state dynamics of the smallest polyene, trans-1,3-butadiene, were studied by femtosecond time-resolved photoelectron-photoion coincidence (TRPEPICO) spectroscopy. The evolution of the excited state wavepacket, created by pumping the bright 1Bu (ππ*) electronic state at its origin of 216 nm, is projected via one- and two-photon ionization at 267 nm onto several ionization continua. The results are interpreted in terms of Koopmans’ correlations and Franck-Condon factors for the excited and cationic states involved. The known predissociative character of the cation excited states is utilized to assign photoelectron bands to specific continua using TRPEPICO spectroscopy. This permits us to report the direct observation of the famously elusive S1(21Ag) dark electronic state during the internal conversion of trans 1,3-butadiene. Our phenomenological analysis permits the spectroscopic determination of several important time constants. We report the overall decay lifetimes of the 11Bu and 21Ag states and observe the re-appearance of the hot ground state molecule. We argue that the apparent dephasing time of the S2(11Bu) state, which leads to the extreme breadth of the absorption spectrum, is principally due to large amplitude torsional motion on the 1Bu surface in conjunction with strong non-adiabatic couplings via conical intersections, whereupon nuclear wavepacket revivals to the initial Franck-Condon region become effectively impossible. In Paper II [W. J. Glover et al., J. Chem. Phys. 148, 164303 (2018)], ab initio multiple spawning is used for on-the-fly computations of the excited state non-adiabatic wavepacket dynamics and their associated TRPEPICO observables, allowing for direct comparisons of experiment with theory.
Effective thermal and mechanical properties of polycrystalline diamond films
Authors: Cheng Hao-Yu , Yang Chi-Yuan , Yang Li-Chueh , Peng Kun-Cheng , Chia Chih-Ta , Liu Shiu-Jen , Lin I-Nan , Lin Kung-Hsuan
Published: April 2018

Polycrystalline diamond films were demonstrated as good candidates for electron field emitters, and their mechanical/thermal properties should thus be considered for real devices. We utilized ultrafast optical techniques to investigate the phonon dynamics of several polycrystalline diamond films, prepared by microwave plasma enhanced chemical vapor deposition. The mechanical properties (longitudinal acoustic velocity) and thermal conductivities of diamond films were evaluated from the coherent and incoherent phonon dynamics, respectively. Ultrananocrystalline diamond films were grown using a CH4 (2%)/Ar plasma, while microcrystalline diamond films were grown using a CH4 (2%)/H2 plasma. The ultrananocrystalline diamond film (with a grain size of several nanometers) possesses low acoustic velocity (14.5 nm/ps) and low thermal conductivity (3.17 W/m K) compared with other kinds of diamond films. The acoustic velocity of diamond films increased abruptly to nearly the same as that of natural diamond and remained there when the rod-shaped diamond grains were induced due to the incorporation of H2 in the growth plasma (CH4/Ar). The thermal conductivities of the materials increased monotonously with increasing incorporation of H2 in the growth plasma (CH4/Ar). The thermal conductivity of 25.6 W/m K was attained for nanocrystalline diamond films containing spherical diamond grains (with a size of several tens of nanometers). Compared with single crystalline diamond, the low thermal conductivity of polycrystalline films results from phonon scattering at the interfaces of grains and amorphous carbon in the boundary phases.
Excited state non-adiabatic dynamics of the smallest polyene, trans 1,3-butadiene. II. Ab initio multiple spawning simulations
Authors: Glover William J. , Mori Toshifumi , Schuurman Michael S. , Boguslavskiy Andrey E. , Schalk Oliver , Stolow Albert , Martínez Todd J.
Published: April 2018

The excited state non-adiabatic dynamics of the smallest polyene, trans 1,3-butadiene (BD), has long been the subject of controversy due to its strong coupling, ultrafast time scales and the difficulties that theory faces in describing the relevant electronic states in a balanced fashion. Here we apply Ab Initio Multiple Spawning (AIMS) using state-averaged complete active space multistate second order perturbation theory [SA-3-CAS(4/4)-MSPT2] which describes both static and dynamic electron correlation effects, providing a balanced description of both the initially prepared bright 11Bu (ππ*) state and non-adiabatically coupled dark 21Ag state of BD. Importantly, AIMS allows for on-the-fly calculations of experimental observables. We validate our approach by directly simulating the time resolved photoelectron-photoion coincidence spectroscopy results presented in Paper I [A. E. Boguslavskiy et al., J. Chem. Phys. 148, 164302 (2018)], demonstrating excellent agreement with experiment. Our simulations reveal that the initial excitation to the 11Bu state rapidly evolves via wavepacket dynamics that follow both bright- and dark-state pathways as well as mixtures of these. In order to test the sensitivity of the AIMS results to the relative ordering of states, we considered two hypothetical scenarios biased toward either the bright 1Bu or the dark 21Ag state. In contrast with AIMS/SA-3-CAS(4/4)-MSPT2 simulations, neither of these scenarios yields favorable agreement with experiment. Thus, we conclude that the excited state non-adiabatic dynamics in BD involves both of these ultrafast pathways.
Collisional radiative model for Ar-O2 mixture plasma with fully relativistic fine structure cross sections
Authors: Priti  , Gangwar Reetesh Kumar , Srivastava Rajesh
Published: April 2018

A collisional radiative (C-R) model has been developed to diagnose the rf generated Ar-O2 (0%–5%) mixture plasma at low temperatures. Since in such plasmas the most dominant process is an electron impact excitation process, we considered several electron impact fine structure transitions in an argon atom from its ground as well as excited states. The cross-sections for these transitions have been obtained using the reliable fully relativistic distorted wave theory. Processes which account for the coupling of argon with the oxygen molecules have been further added to the model. We couple our model to the optical spectroscopic measurements reported by Jogi et al. [J. Phys. D: Appl. Phys. 47, 335206 (2014)]. The plasma parameters, viz. the electron density (ne) and the electron temperature (Te) as a function of O2 concentration have been obtained using thirteen intense emission lines out of 3p54p → 3p54s transitions observed in their spectroscopic measurements. It is found that as the content of O2 in Ar increases from 0%–5%, Te increases in the range 0.85–1.7 eV, while the electron density decreases from 2.76 × 1012–2.34 × 1011 cm−3. The Ar-3p54s (1si) fine-structure level populations at our extracted plasma parameters are found to be in very good agreement with those obtained from the measurements. Furthermore, we have estimated the individual contributions coming from the ground state, 1si manifolds and cascade contributions to the population of the radiating Ar-3p54p (2pi) states as a function of a trace amount of O2. Such information is very useful to understand the importance of various processes occurring in the plasma.
Al-, Y-, and La-doping effects favoring intrinsic and field induced ferroelectricity in HfO2: A first principles study
Authors: Materlik Robin , Künneth Christopher , Falkowski Max , Mikolajick Thomas , Kersch Alfred
Published: April 2018

III-valent dopants have shown to be most effective in stabilizing the ferroelectric, crystalline phase in atomic layer deposited, polycrystalline HfO2 thin films. On the other hand, such dopants are commonly used for tetragonal and cubic phase stabilization in ceramic HfO2. This difference in the impact has not been elucidated so far. The prospect is a suitable doping to produce ferroelectric HfO2 ceramics with a technological impact. In this paper, we investigate the impact of Al, Y, and La doping, which have experimentally proven to stabilize the ferroelectric Pca21 phase in HfO2, in a comprehensive first-principles study. Density functional theory calculations reveal the structure, formation energy, and total energy of various defects in HfO2. Most relevant are substitutional electronically compensated defects without oxygen vacancy, substitutional mixed compensated defects paired with a vacancy, and ionically compensated defect complexes containing two substitutional dopants paired with a vacancy. The ferroelectric phase is strongly favored with La and Y in the substitutional defect. The mixed compensated defect favors the ferroelectric phase as well, but the strongly favored cubic phase limits the concentration range for ferroelectricity. We conclude that a reduction of oxygen vacancies should significantly enhance this range in Y doped HfO2 thin films. With Al, the substitutional defect hardly favors the ferroelectric phase before the tetragonal phase becomes strongly favored with the increasing concentration. This could explain the observed field induced ferroelectricity in Al-doped HfO2. Further Al defects are investigated, but do not favor the f-phase such that the current explanation remains incomplete for Al doping. According to the simulation, doping alone shows clear trends, but is insufficient to replace the monoclinic phase as the ground state. To explain this fact, some other mechanism is needed.
Prediction of air blast mitigation in an array of rigid obstacles using smoothed particle hydrodynamics
Authors: Prasanna Kumar S. S. , Patnaik B. S. V. , Ramamurthi K.
Published: April 2018

The mitigation of blast waves propagating in air and interacting with rigid barriers and obstacles is numerically investigated using the mesh-free smoothed particle hydrodynamics method. A novel virtual boundary particle procedure with a skewed gradient wall boundary treatment is applied at the interfaces between air and rigid bodies. This procedure is validated with closed-form solutions for strong and weak shock reflection from rigid surfaces, supersonic flows over a wedge, formation of reflected, transverse, and Mach stem shocks, and also earlier experiments on interaction of a blast wave with concrete blocks. The mitigation of the overpressure and impulse transmitted to the protected structure due to an array of rigid obstacles of different shapes placed in the path of the blast wave is thereafter determined and discussed in the context of the existing experimental and numerical studies. It is shown that blockages having the shape of a right facing triangle or square placed in tandem or staggered provide better mitigation. The influence of the distance between the blockage array and protected structure is assessed, and the incorporation of a gap in the blockages is shown to improve the mitigation. The mechanisms responsible for the attenuation of air blast are identified through the simulations.
Observing spatio-temporal dynamics of excitable media using reservoir computing
Authors: Zimmermann Roland S. , Parlitz Ulrich
Published: April 2018

We present a dynamical observer for two dimensional partial differential equation models describing excitable media, where the required cross prediction from observed time series to not measured state variables is provided by Echo State Networks receiving input from local regions in space, only. The efficacy of this approach is demonstrated for (noisy) data from a (cubic) Barkley model and the Bueno-Orovio-Cherry-Fenton model describing chaotic electrical wave propagation in cardiac tissue.
Convergence of high order memory kernels in the Nakajima-Zwanzig generalized master equation and rate constants: Case study of the spin-boson model
Authors: Xu Meng , Yan Yaming , Liu Yanying , Shi Qiang
Published: April 2018

The Nakajima-Zwanzig generalized master equation provides a formally exact framework to simulate quantum dynamics in condensed phases. Yet, the exact memory kernel is hard to obtain and calculations based on perturbative expansions are often employed. By using the spin-boson model as an example, we assess the convergence of high order memory kernels in the Nakajima-Zwanzig generalized master equation. The exact memory kernels are calculated by combining the hierarchical equation of motion approach and the Dyson expansion of the exact memory kernel. High order expansions of the memory kernels are obtained by extending our previous work to calculate perturbative expansions of open system quantum dynamics [M. Xu et al., J. Chem. Phys. 146, 064102 (2017)]. It is found that the high order expansions do not necessarily converge in certain parameter regimes where the exact kernel show a long memory time, especially in cases of slow bath, weak system-bath coupling, and low temperature. Effectiveness of the Padé and Landau-Zener resummation approaches is tested, and the convergence of higher order rate constants beyond Fermi’s golden rule is investigated.
Birefringence and incipient plastic deformation in elastically overdriven [100] CaF2 under shock compression
Authors: Li Y. , Zhou X. M. , Cai Y. , Liu C. L. , Luo S. N.
Published: April 2018

[100] CaF2 single crystals are shock-compressed via symmetric planar impact, and the flyer plate–target interface velocity histories are measured with a laser displacement interferometry. The shock loading is slightly above the Hugoniot elastic limit to investigate incipient plasticity and its kinetics, and its effects on optical properties and deformation inhomogeneity. Fringe patterns demonstrate different features in modulation of fringe amplitude, including birefringence and complicated modulations. The birefringence is attributed to local lattice rotation accompanying incipient plasticity. Spatially resolved measurements show inhomogeneity in deformation, birefringence, and fringe pattern evolutions, most likely caused by the inhomogeneity associated with lattice rotation and dislocation slip. Transiently overdriven elastic states are observed, and the incubation time for incipient plasticity decreases inversely with increasing overdrive by the elastic shock.
The generalized confluent supersymmetry algorithm: Representations and integral formulas
Authors: Schulze-Halberg Axel , Yeşİltaş Özlem
Published: April 2018

We extend the confluent version of the higher-order supersymmetry (SUSY) formalism to general linear differential equations of second order. Closed-form representations of transformation functions, their Wronskians, and of the general solutions to SUSY-transformed equations are derived. We use these results to construct formulas for resolving multiple integrals of special functions in terms of Wronskians.
Analysis of uncertainties and convergence of the statistical quantities in turbulent wall-bounded flows by means of a physically based criterion
Authors: Andrade João Rodrigo , Martins Ramon Silva , Thompson Roney Leon , Mompean Gilmar , da Silveira Neto Aristeu
Published: April 2018

The present paper provides an analysis of the statistical uncertainties associated with direct numerical simulation (DNS) results and experimental data for turbulent channel and pipe flows, showing a new physically based quantification of these errors, to improve the determination of the statistical deviations between DNSs and experiments. The analysis is carried out using a recently proposed criterion by Thompson et al. [“A methodology to evaluate statistical errors in DNS data of plane channel flows,” Comput. Fluids 130, 1–7 (2016)] for fully turbulent plane channel flows, where the mean velocity error is estimated by considering the Reynolds stress tensor, and using the balance of the mean force equation. It also presents how the residual error evolves in time for a DNS of a plane channel flow, and the influence of the Reynolds number on its convergence rate. The root mean square of the residual error is shown in order to capture a single quantitative value of the error associated with the dimensionless averaging time. The evolution in time of the error norm is compared with the final error provided by DNS data of similar Reynolds numbers available in the literature. A direct consequence of this approach is that it was possible to compare different numerical results and experimental data, providing an improved understanding of the convergence of the statistical quantities in turbulent wall-bounded flows.
Controllable asymmetric transmission via gap-tunable acoustic metasurface
Authors: Liu Bingyi , Jiang Yongyuan
Published: April 2018

In this work, we utilize the acoustic gradient metasurface (AGM) of a bilayer configuration to realize the controllable asymmetric transmission. Relying on the adjustable gap between the two composing layers, the metasurface could switch from symmetric transmission to asymmetric transmission at a certain gap value. The underlying mechanism is attributed to the interference between the forward diffracted waves scattered by the surface bound waves at two air-AGM interfaces, which is apparently influenced by the interlayer distance. We further utilize the hybrid acoustic elements to construct the desired gradient metasurface with a tunable gap and validate the controllable asymmetric transmission with full-wave simulations. Our work provides the solution for actively controlling the transmission property of an acoustic element, which shows potential application in acoustic communication as a dynamic tunable acoustic diode.
A compact large-format streak tube for imaging lidar
Authors: Hui Dandan , Luo Duan , Tian Liping , Lu Yu , Chen Ping , Wang Junfeng , Sai Xiaofeng , Wen Wenlong , Wang Xing , Xin Liwei , Zhao Wei , Tian Jinshou
Published: April 2018

The streak tubes with a large effective photocathode area, large effective phosphor screen area, and high photocathode radiant sensitivity are essential for improving the field of view, depth of field, and detectable range of the multiple-slit streak tube imaging lidar. In this paper, a high spatial resolution, large photocathode area, and compact meshless streak tube with a spherically curved cathode and screen is designed and tested. Its spatial resolution reaches 20 lp/mm over the entire Φ28 mm photocathode working area, and the simulated physical temporal resolution is better than 30 ps. The temporal distortion in our large-format streak tube, which is shown to be a non-negligible factor, has a minimum value as the radius of curvature of the photocathode varies. Furthermore, the photocathode radiant sensitivity and radiant power gain reach 41 mA/W and 18.4 at the wavelength of 550 nm, respectively. Most importantly, the external dimensions of our streak tube are no more than Φ60 mm × 110 mm.
A micromachined device describing over a hundred orders of parametric resonance
Authors: Jia Yu , Du Sijun , Arroyo Emmanuelle , Seshia Ashwin A.
Published: April 2018

Parametric resonance in mechanical oscillators can onset from the periodic modulation of at least one of the system parameters, and the behaviour of the principal (1st order) parametric resonance has long been well established. However, the theoretically predicted higher orders of parametric resonance, in excess of the first few orders, have mostly been experimentally elusive due to the fast diminishing instability intervals. A recent paper experimentally reported up to 28 orders in a micromachined membrane oscillator. This paper reports the design and characterisation of a micromachined membrane oscillator with a segmented proof mass topology, in an attempt to amplify the inherent nonlinearities within the membrane layer. The resultant oscillator device exhibited up to over a hundred orders of parametric resonance, thus experimentally validating these ultra-high orders as well as overlapping instability transitions between these higher orders. This research introduces design possibilities for the transducer and dynamic communities, by exploiting the behaviour of these previously elusive higher order resonant regimes.
Reference dependence of the two-determinant coupled-cluster method for triplet and open-shell singlet states of biradical molecules
Authors: Lutz Jesse J. , Nooijen Marcel , Perera Ajith , Bartlett Rodney J.
Published: April 2018

We study the performance of the two-determinant (TD) coupled-cluster (CC) method which, unlike conventional ground-state single-reference (SR) CC methods, can, in principle, provide a naturally spin-adapted treatment of the lowest-lying open-shell singlet (OSS) and triplet electronic states. Various choices for the TD-CC reference orbitals are considered, including those generated by the multi-configurational self-consistent field method. Comparisons are made with the results of high-level SR-CC, equation-of-motion (EOM) CC, and multi-reference EOM calculations performed on a large test set of over 100 molecules with low-lying OSS states. It is shown that in cases where the EOMCC reference function is poorly described, TD-CC can provide a significantly better quantitative description of OSS total energies and OSS-triplet splittings.
Effective g factor of 2D holes in strained Ge quantum wells
Authors: Drichko I. L. , Dmitriev A. A. , Malysh V. A. , Smirnov I. Yu. , von Känel H. , Kummer M. , Chrastina D. , Isella G.
Published: April 2018

The effective g-factor of 2D holes in modulation doped p-SiGe/Ge/SiGe structures was studied. The AC conductivity of samples with hole densities from 3.9 × 1011 to 6.2 × 1011 cm−2 was measured in perpendicular magnetic fields up to 8 T using a contactless acoustic method. From the analysis of the temperature dependence of conductivity oscillations, the g⊥-factor of each sample was determined. The g⊥-factor was found to be decreasing approximately linearly with hole density. This effect is attributed to the non-parabolicity of the valence band.
Particle simulation of electromagnetic emissions from electrostatic instability driven by an electron ring beam on the density gradient
Authors: Horký Miroslav , Omura Yoshiharu , Santolík Ondřej
Published: April 2018

This paper presents the wave mode conversion between electrostatic and electromagnetic waves on the plasma density gradient. We use 2-D electromagnetic code KEMPO2 implemented with the generation of density gradient to simulate such a conversion process. In the dense region, we use ring beam instability to generate electron Bernstein waves and we study the temporal evolution of wave spectra, velocity distributions, Poynting flux, and electric and magnetic energies to observe the wave mode conversion. Such a conversion process can be a source of electromagnetic emissions which are routinely measured by spacecraft on the plasmapause density gradient.
Interface energy band alignment at the all-transparent p-n heterojunction based on NiO and BaSnO3
Authors: Zhang Jiaye , Han Shaobo , Luo Weihuang , Xiang Shuhuai , Zou Jianli , Oropeza Freddy E. , Gu Meng , Zhang Kelvin H. L.
Published: April 2018

Transparent oxide semiconductors hold great promise for many optoelectronic devices such as transparent electronics, UV-emitting devices, and photodetectors. A p-n heterojunction is the most ubiquitous building block to realize these devices. In this work, we report the fabrication and characterization of the interface properties of a transparent heterojunction consisting of p-type NiO and n-type perovskite BaSnO3. We show that high-quality NiO thin films can be epitaxially grown on BaSnO3 with sharp interfaces because of a small lattice mismatch (∼1.3%). The diode fabricated from this heterojunction exhibits rectifying behavior with a ratio of 500. X-ray photoelectron spectroscopy reveals a type II or “staggered” band alignment with valence and conduction band offsets of 1.44 eV and 1.86 eV, respectively. Moreover, a large upward band bending potential of 0.90 eV for BaSnO3 and a downward band bending potential of 0.15 eV for NiO were observed in the interface region. Such electronic properties have important implication for optoelectronic applications as the large built-in potential provides favorable energetics for photo-generated electron-hole separation/migration.
The role of prosody in early word learning
Authors: Thorson Jill C.
Published: April 2018

Successful word learning in first language acquisition requires three
components: segmentation of words from a continuous speech stream,
identification of real-word referents or concepts, and mapping of
linguistic label to meaning. This review presents behavioral
evidence for how prosody is integral to each of these processes,
with particular prosodic structures creating optimal word learning
environments. Different prosodic strategies aid the three facets of
word learning, with rhythm, stress, intonation, and phrasing
interacting to facilitate learning. For example, recent behavioral
work shows that word learning is enhanced when words appear at
prosodic phrase boundaries and when new words carry a more prominent
pitch accent. Finally, an integrative account of word learning is
discussed in light of these findings.
Gradual development of focus prosody and affect
prosody comprehension
Authors: Ito Kiwako
Published: April 2018

Excellence in communication skills requires an ability to
appropriately represent the discourse structure including focus, as
well as good comprehension of speaker affect. Both focus and affect
are communicated in large part through prosody, so comprehension and
production of the accompanying prosody is essential. However, past
studies on focus prosody have been both theoretically and
methodologically separated from the research on affect prosody. (In
this chapter, I use the term ‘focus prosody’ to refer to prosodic
phenomena that are either produced or perceived as the cue to a
specific part of speech that conveys the focal content of a message.
This includes ‘narrow focus’, which is defined in terms of the
informational scope (e.g., answers to Wh-questions), and
‘contrastive focus’, which is a subtype of narrow focus that evokes
interpretational alternatives.) This chapter argues that the
suggested difference in the developmental trajectory (i.e., focus
prosody develops slower as compared to affect prosody) may be an
artifact of the perspective divergence, and points out that the
mastery of prosodic skills in both these domains must be necessarily
gradual – though they may not develop
hand-in-hand. A holistic approach that considers the interaction
between affect prosody and focus prosody is proposed as a future
direction of the research on prosodic development within and across
individuals.
Bilingual children’s prosodic development
Authors: Lleó Conxita
Published: April 2018

This chapter focuses on various domains of prosodic development –
syllables, metrical feet, prosodic words, stress patterns,
phonological phrases, intonation and rhythm – as they are acquired
by bilingual children, exposed to two languages from birth: a
societal or majority language and a minority or heritage language.
The studies reviewed in this chapter discuss the bilingual
acquisition of these prosodic domains and the influence of one
language onto the other when children develop surrounded by two
languages in contact. The discussion deals with the various aspects
of the acquisition of prosody and prosodic structure described in
the main section of the chapter, and reports on the outcomes of
cross-language interaction: acceleration, delay, transfer, order of
acquisition, and fusion.
Effects of carbon dioxide on metabolite production and bacterial communities during kimchi fermentation
Authors: Park Doo Hyun
Published: April 2018

Bacterial communities and metabolites in kimchi fermented under conventional conditions (CC) compared to CO2-rich environments (CO2) were analyzed. After a 20-day fermentation, lactic and acetic acid productions were 54 and 69 mM under CC, and 19 and 12 mM under CO2, respectively. The final pH of kimchi fermented under CC (CC-fermenting) and CO2 (CO2-fermenting) were 4.1 and 4.7, respectively. For bacterial communities, OTU and Chao1 indices were both 35 in fresh kimchi, 10 and 15 in CC-fermenting kimchi, and 8 and 24 in CO2-fermenting kimchi, respectively. Shannon and Simpson indices were 3.47 and 0.93 in fresh kimchi, 1.87–0.06 and 0.46–0.01 in CC-fermenting kimchi, and 1.65–0.44 and 0.63–0.12 in CO2-fermenting kimchi, respectively. Non-lactic acid bacteria were eliminated in fermenting kimchi after 12 days under CC and 6 days under CO2. I conclude that carbon dioxide can alter bacterial communities, reduce metabolite production, and improve fermented kimchi quality.
OPA1-anchored PKA phosphorylates perilipin 1 on S522 and S497 in adipocytes differentiated from human adipose stem cells
Authors: Rogne Marie , Chu Dinh-Toi , Küntziger Thomas M. , Mylonakou Maria-Niki , Collas Philippe , Tasken Kjetil
Published: April 2018

Optic atrophy 1 (OPA1) is the A-kinase anchoring protein targeting the pool of protein kinase A (PKA) responsible for perilipin 1 phosphorylation, a gatekeeper for lipolysis. However, the involvement of OPA1-bound PKA in the downstream regulation of lipolysis is unknown. Here we show up-regulation and relocation of OPA1 from mitochondria to lipid droplets during adipocytic differentiation of human adipose stem cells. We employed various biochemical and immunological approaches to demonstrate that OPA1-bound PKA phosphorylates perilipin 1 at S522 and S497 on lipolytic stimulation. We show that the first 30 amino acids of OPA1 are essential for its lipid droplet localization as is OMA1-dependent processing. Finally, our results indicate that presence of OPA1 is necessary for lipolytic phosphorylation of downstream targets. Our results show for the first time, to our knowledge, how OPA1 mediates adrenergic control of lipolysis in human adipocytes by regulating phosphorylation of perilipin 1.
Haplotype phasing in single-cell DNA-sequencing data
Authors: Satas Gryte , Raphael Benjamin J
Published: April 2018

Motivation

Current technologies for single-cell DNA sequencing require whole-genome amplification (WGA), as a single cell contains too little DNA for direct sequencing. Unfortunately, WGA introduces biases in the resulting sequencing data, including non-uniformity in genome coverage and high rates of allele dropout. These biases complicate many downstream analyses, including the detection of genomic variants.

Results

We show that amplification biases have a potential upside: long-range correlations in rates of allele dropout provide a signal for phasing haplotypes at the lengths of amplicons from WGA, lengths which are generally longer than than individual sequence reads. We describe a statistical test to measure concurrent allele dropout between single-nucleotide polymorphisms (SNPs) across multiple sequenced single cells. We use results of this test to perform haplotype assembly across a collection of single cells. We demonstrate that the algorithm predicts phasing between pairs of SNPs with higher accuracy than phasing from reads alone. Using whole-genome sequencing data from only seven neural cells, we obtain haplotype blocks that are orders of magnitude longer than with sequence reads alone (median length 10.2 kb versus 312 bp), with error rates <2%. We demonstrate similar advantages on whole-exome data from 16 cells, where we obtain haplotype blocks with median length 9.2 kb—comparable to typical gene lengths—compared with median lengths of 41 bp with sequence reads alone, with error rates <4%. Our algorithm will be useful for haplotyping of rare alleles and studies of allele-specific somatic aberrations.

Availability and implementation

Source code is available at https://www.github.com/raphael-group.

Supplementary information

Supplementary data are available at Bioinformatics online.
Cluster Locator, online analysis and visualization of gene clustering
Authors: Pazos Obregón Flavio , Soto Pablo , Lavín José Luis , Cortázar Ana Rosa , Barrio Rosa , Aransay Ana María , Cantera Rafael
Published: April 2018

Genes sharing functions, expression patterns or quantitative traits are not randomly distributed along eukaryotic genomes. In order to study the distribution of genes that share a given feature, we present Cluster Locator, an online analysis and visualization tool. Cluster Locator determines the number, size and position of all the clusters formed by the protein-coding genes on a list according to a given maximum gap, the percentage of gene clustering of the list and its statistical significance. The output includes a visual representation of the distribution of genes and gene clusters along the reference genome.

Availability and implementation

Cluster Locator is freely available at http://clusterlocator.bnd.edu.uy/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Epidemiology and Risk Factors for Cryptosporidiosis in Children From 8 Low-income Sites: Results From the MAL-ED Study
Authors: Korpe Poonum S , Valencia Cristian , Haque Rashidul , Mahfuz Mustafa , McGrath Monica , Houpt Eric , Kosek Margaret , McCormick Benjamin J J , Penataro Yori Pablo , Babji Sudhir , Kang Gagandeep , Lang Dennis , Gottlieb Michael , Samie Amidou , Bessong Pascal , Faruque A S G , Mduma Esto , Nshama Rosemary , Havt Alexandre , Lima Ila F N , Lima Aldo A M , Bodhidatta Ladaporn , Shreshtha Ashish , Petri William A , Ahmed Tahmeed , Duggal Priya
Published: April 2018

Background

Cryptosporidium species are enteric protozoa that cause significant morbidity and mortality in children worldwide. We characterized the epidemiology of Cryptosporidium in children from 8 resource-limited sites in Africa, Asia, and South America.

Methods

Children were enrolled within 17 days of birth and followed twice weekly for 24 months. Diarrheal and monthly surveillance stool samples were tested for Cryptosporidium by enzyme-linked immunosorbent assay. Socioeconomic data were collected by survey, and anthropometry was measured monthly.

Results

Sixty-five percent (962/1486) of children had a Cryptosporidium infection and 54% (802/1486) had at least 1 Cryptosporidium-associated diarrheal episode. Cryptosporidium diarrhea was more likely to be associated with dehydration (16.5% vs 8.3%, P < .01). Rates of Cryptosporidium diarrhea were highest in the Peru (10.9%) and Pakistan (9.2%) sites. In multivariable regression analysis, overcrowding at home was a significant risk factor for infection in the Bangladesh site (odds ratio, 2.3 [95% confidence interval {CI}, 1.2–4.6]). Multiple linear regression demonstrated a decreased length-for-age z score at 24 months in Cryptosporidium-positive children in the India (β = –.26 [95% CI, –.51 to –.01]) and Bangladesh (β = –.20 [95% CI, –.44 to .05]) sites.

Conclusions

This multicountry cohort study confirmed the association of Cryptosporidium infection with stunting in 2 South Asian sites, highlighting the significance of cryptosporidiosis as a risk factor for poor growth. We observed that the rate, age of onset, and number of repeat infections varied per site; future interventions should be targeted per region to maximize success.
Colonization With Levofloxacin-resistant Extended-spectrum β-Lactamase-producing Enterobacteriaceae and Risk of Bacteremia in Hematopoietic Stem Cell Transplant Recipients
Authors: Satlin Michael J , Chavda Kalyan D , Baker Thomas M , Chen Liang , Shashkina Elena , Soave Rosemary , Small Catherine B , Jacobs Samantha E , Shore Tsiporah B , van Besien Koen , Westblade Lars F , Schuetz Audrey N , Fowler Vance G , Jenkins Stephen G , Walsh Thomas J , Kreiswirth Barry N
Published: April 2018

Background

Bacteremia caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) is associated with inadequate empirical therapy and substantial mortality in neutropenic patients. Strategies are needed to identify neutropenic patients at high risk of these infections.

Methods

From April 2014 to September 2016, we collected perianal swabs, both at admission and weekly thereafter, from patients undergoing hematopoietic stem cell transplantation (HSCT). Patients received prophylactic levofloxacin while neutropenic. Swabs were plated onto selective agar, colonies were identified and underwent antimicrobial susceptibility testing, and phenotypic ESBL testing and polymerase chain reaction for β-lactamase genes were performed on ceftriaxone-resistant Enterobacteriaceae. We then determined the prevalence of pre-transplant ESBL-E colonization and risk of ESBL-E bacteremia. Colonizing and bloodstream isolates from patients with ESBL-E bacteremia underwent multilocus sequence typing and pulsed-field gel electrophoresis.

Results

We analyzed 312 patients, including 212 allogeneic and 100 autologous HSCT recipients. Ten percent (31/312) of patients had pre-transplant ESBL-E colonization. Susceptibility rates of colonizing ESBL-E were: levofloxacin, 25%; cefepime, 9%; piperacillin-tazobactam, 84%; and meropenem, 97%. Of 31 patients colonized with ESBL-E pre-transplant, 10 (32%) developed ESBL-E bacteremia during their transplant admission, compared to 1 (0.4%) of 281 patients not colonized with ESBL-E (P < .001). All bloodstream ESBL-E were levofloxacin-resistant and colonizing and bloodstream isolates from individual patients had identical genotypic profiles.

Conclusions

HSCT recipients who are colonized with levofloxacin-resistant ESBL-E pre-transplant and receive levofloxacin prophylaxis have high rates of bacteremia from their colonizing strain during neutropenia. Assessing for ESBL-E colonization in neutropenic patients could lead to optimization of empirical antibacterial therapy.