bluuebunny/crossref_metadata_2025 huggingface dataset:
The General and Social Health Long-Term Outcome of Adult Epilepsy Patients at the Kork Epilepsy Center
Authors: Burkhardt Maxi , Bacher Matthias , Kornmeier Reinhold , Kurth Christoph , Staack Anke , Steinhoff Bernhard
Published: May 2018

Objectives The majority of epidemiological studies show that there is an increased burden of somatic comorbidities among people with epilepsy (PWE) compared with the general population. We sought that in the subgroup of patients with satisfactory and stable seizure situation and healthy style of living, the general health and quality of life might be similar to people without epilepsy and investigated the long-term outcome and the prevalence of comorbidities and the social outcome of adult patients who had been continuously treated at our center for at least 25 years.

Material and methods We consecutively collected our adult out-patients for 10 months and identified those patients who had been treated at our center for at least 25 years. Among this group we assessed demographic data, epilepsy syndrome, seizure situation, antiepileptic therapy, the number of previous AEDs, the socioeconomic situation and co-morbidities.

Results Out of a total of 1672 patients, 14.4 % (n = 241) patients fulfilled our inclusion criterion. In 200 the files allowed an appropriate analysis of the data. Mean treatment duration in Kork was 36 years (25 – 52). 60% of patients were seizure-free for more than one year. 80% of the seizure-free patients did not complain of adverse events. Adverse events were more often among patients with ongoing seizures. Somnolence, gait disturbances and tremor were the leading symptoms. Better seizure outcome correlated with higher education, better professional education and lower unemployment rates. Diseases such as cardiovascular diseases or diabetes mellitus were not more frequent than in the general population. PWE do not have necessarily an impaired prognosis of their general health.
One-Pot Preparation of Stable Organoboronate Reagents for the Functionalization of Unsaturated Four- and Five-Membered Carbo­- and Heterocycles
Authors: Didier Dorian , Baumann Andreas , Eisold Michael , Music Arif
Published: May 2018

Combining a facile preparation of organoboronates with their remarkable stability and functional group tolerance allows for the straightforward synthesis of four- and five-membered carbo- and hetero­cycles. While most strategies rely on the ex situ preparation of boronic acids as isolated intermediates, we demonstrate that in situ transmetalation of sensitive organometallics with boron alkoxides can lead to great stabilization of such species at room temperature. A considerable extension of the library of unsaturated strained structures is achieved through these sequences, expanding the potential applicability of such unusual building blocks.
Synthesis of Isoxazolines and Isoxazoles via Metal-Free Desulfitative Cyclization
Authors: Sun Qiu , He Ling , Cheng Jiaxin , Yang Ze , Li Yuansheng , Xi Yulan
Published: May 2018

A novel, one-pot reaction for the synthesis of isoxazolines and isoxazoles is developed via a cascade process under metal-free conditions. The approach involves the formation of intramolecular C–N and C–O bonds and intermolecular C–C bonds from aromatic alkenes or alkynes and N-hydroxysulfonamides using hypervalent iodine(VII) and iodine as the oxidant. Activation of C–H and C–C bonds/construction of C–O bonds/elimination of SO2/C–N bond formation is achieved in sequence­ in the reaction system.
Review of Eyelid Reconstruction Techniques after Mohs Surgery
Authors: Patel Sagar , Itani Kamel
Published: May 2018

Mohs micrographic surgery achieves high cure rates while preserving healthy tissue making it the optimal treatment for skin cancer. The goals of eyelid reconstruction after Mohs surgery include restoring eyelid structure and function while attaining acceptable aesthetic results. Given the variety of eyelid defects encountered after Mohs surgery, a thorough understanding of the complex eyelid anatomy as well as an in-depth knowledge of the numerous reconstructive techniques available are required to accomplish these reconstructive goals. In this article, the authors review eyelid anatomy and discuss a variety of techniques used for the reconstruction of defects involving the periocular region.
Follow-up Study on the Effect of Risk-Stratified, Protocol-Based Perioperative Antibiotic Prophylaxis on Postoperative Infections in a Tertiary Care Neurosurgical Department over 10 Years (2007–2016)
Authors: Agarwal Ashutosh , Borkar Sachin , Kapil Arti , Dabral Jyotsna , Suri Ashish , Kale Shashank , Mahapatra Ashok
Published: May 2018

Objective To study the effectiveness of risk-stratified prophylactic antibiotic policy on meningitis, surgical site, and extraneurosurgical site infections among postoperative neurosurgical patients from the year 2007 to 2016. This is a follow-up study for a similar analysis done from 1994 to 2006, which is published in Neurosurgery.

Methods Retrospective audit of 30,251 consecutive neurosurgical cases from January 2007 through December 2016 at a tertiary care center with culture positivity in samples taken from patients showing clinical/radiologic evidence of infection as an objective marker of postoperative infection. Risk-stratified, variable-duration antibiotic prophylaxis policy was followed over 10 years; it was modified in the year 2014, and infections from 2007 to 2013 were compared with 2014 to 2016.

Results Over 10 years, there were 2,782 infections in 2,193 (9.45%) patients with meningitis in 281 (0.96%), bloodstream infections in 596 (2.05%), respiratory infections in 913 (3.11%), urinary tract infections (UTIs) in 697 (2.30%), and wound infections in 295 (1.02%) patients. On comparison, the proportion of infections between 2014 and 2016 was significantly lower than that between 2007 and 2013 (4.61 ± 0.14% vs. 11.52 ± 2.2%, p = 0.001). The most common microorganisms were non–lactose-fermenting gram-negative bacilli, followed by Klebsiella and Escherichia coli. The proportion of gram-positive cocci (GPC) was 16.2% with methicillin-resistant Staphylococcus aureus (MRSA) accounting for 5.5% cases.

Conclusion A risk-stratified, variable-duration prophylactic antibiotic protocol helps in reducing postoperative meningitis, surgical site, and extraneurosurgical site infections in neurosurgical patients, and prophylaxis with first-generation cephalosporin and aminoglycoside is effective.
Functional Outcome for Chiari Malformation Using a Novel Scoring System
Authors: Kumar Anil , Pruthi Nupur , Devi Bhagavatula , Gupta Arun
Published: May 2018

Background The authors report functional outcomes comparing various surgical techniques, using a Chiari-specific assessment tool. They also intend to externally validate the performance of the CCOS by comparing with gestalt outcome.

Methods Total cohort comprised 73 surgically treated patients, and patients were divided into two groups: patients who were operated upon at the authors’ institute and those who were evaluated at their institute but underwent surgery elsewhere due to various reasons. Functional outcome was evaluated on the basis of the Chicago Chiari outcome scale (CCOS) and gestalt outcome scale. Mean duration of follow-up was 10.23 ± 5.8 months.

Results In the authors’ cohort of 73 patients, 76.70% (n = 56) were improved, 23.30% (n = 17) were unchanged, and none of them deteriorated. The median CCOS was 14 ± 1.34 (range: 11–16). There was no statistical difference in outcome between the different operative groups (foramen magnum decompression, duraplasty, tonsillar resection “other”). The CCOS value of 14 has excellent sensitivity (0.95) and good specificity (0.746) for identifying patients with good gestalt outcome.

Conclusion The authors found a clear correlation between higher CCOS score and gestalt outcome. There was no statistical difference in outcome between the different operative groups.
Parenteral Nutrition in Interventional Radiology: Consideration and Management of the Patient
Authors: Kapoor Baljendra , Wang Weiping , Moon Eunice
Published: May 2018

The approach for patients on parenteral nutrition is typically multidisciplinary. Catheters for parenteral nutrition are primarily placed by interventional radiologists under image guidance. Therefore, adequate knowledge of different catheters, including their indications and complications, as well as management of the complications is exceptionally important for interventional radiologists as well as the referring service. In this review, we discuss different aspects of parenteral nutrition, including infectious complications and the strategy for their prevention and management.
Red Blood Cell Transfusions Following Resection of Skull Base Meningiomas: Risk Factors and Clinical Outcomes
Authors: Lagman Carlito , Sheppard John , Beckett Joel , Tucker Alexander , Nagasawa Daniel , Prashant Giyarpuram , Ziman Alyssa , Yang Isaac
Published: May 2018

Objective This article identifies risk factors for and investigates clinical outcomes of postoperative red blood cell transfusion in patients with skull base meningiomas.

Design Retrospective cohort study.

Setting Single academic medical center.

Participants The transfusion group included patients who had skull base meningiomas and who received packed red blood cell (RBC) transfusion within 7 days of surgery. The no transfusion group included patients who had skull base meningiomas but who did not have RBCs transfused within 7 days of surgery.

Main Outcome Measures In-hospital complication rate, length of stay (LOS), and discharge disposition.

Results One hundred and ninety-six patients had a craniotomy for resection of a meningioma at our institution from March 2013 to January 2017. Seven patients had skull base meningiomas and received RBC transfusion within 7 days of surgery (the transfusion group). The skull base was an independent risk factor for transfusion after we controlled for the effect of meningioma size (OR 3.89, 95% CI 1.34, 11.25). Operative time greater than 10 hours was an independent risk factor for prolonged hospital stay (OR 8.84, 95% CI 1.08, 72.10) once we controlled for the effect of transfusion. In contrast, transfusion did not independently impact LOS or discharge disposition once we controlled for the effect of operative time.

Conclusions The skull base is an independent predictor of RBC transfusion. However, RBC transfusion alone cannot predict LOS or discharge disposition in patients who undergo surgical resection of a skull base meningioma.
Integrable nonlinear Schrödinger system on a lattice with three structural elements in the unit cell
Authors: Vakhnenko Oleksiy O.
Published: May 2018

Developing the idea of increasing the number of structural elements in the unit cell of a quasi-one-dimensional lattice as applied to the semi-discrete integrable systems of nonlinear Schrödinger type, we construct the zero-curvature representation for the general integrable nonlinear system on a lattice with three structural elements in the unit cell. The integrability of the obtained general system permits to find explicitly a number of local conservation laws responsible for the main features of system dynamics and in particular for the so-called natural constraints separating the field variables into the basic and the concomitant ones. Thus, considering the reduction to the semi-discrete integrable system of nonlinear Schrödinger type, we revealed the essentially nontrivial impact of concomitant fields on the Poisson structure and on the whole Hamiltonian formulation of system dynamics caused by the nonzero background values of these fields. On the other hand, the zero-curvature representation of a general nonlinear system serves as an indispensable key to the dressing procedure of system integration based upon the Darboux transformation of the auxiliary linear problem and the implicit Bäcklund transformation of field variables. Due to the symmetries inherent to the six-component semi-discrete integrable nonlinear Schrödinger system with attractive-type nonlinearities, the Darboux–Bäcklund dressing scheme is shown to be simplified considerably, giving rise to the appropriately parameterized multi-component soliton solution consisting of six basic and four concomitant components.
Tuning metal-insulator behavior in LaTiO3/SrTiO3 heterostructures integrated directly on Si(100) through control of atomic layer thickness
Authors: Ahmadi-Majlan Kamyar , Chen Tongjie , Lim Zheng Hui , Conlin Patrick , Hensley Ricky , Chrysler Matthew , Su Dong , Chen Hanghui , Kumah Divine P. , Ngai Joseph H.
Published: May 2018

We present electrical and structural characterization of epitaxial LaTiO3/SrTiO3 heterostructures integrated directly on Si(100). By reducing the thicknesses of the heterostructures, an enhancement in carrier-carrier scattering is observed in the Fermi liquid behavior, followed by a metal to insulator transition in the electrical transport. The insulating behavior is described by activated transport, and its onset occurs near an occupation of 1 electron per Ti site within the SrTiO3, providing evidence for a Mott driven transition. We also discuss the role that structure and gradients in strain could play in enhancing the carrier density. The manipulation of Mott metal-insulator behavior in oxides grown directly on Si opens the pathway to harnessing strongly correlated phenomena in device technologies.
Perspective: Optical measurement of feature dimensions and shapes by scatterometry
Authors: Diebold Alain C. , Antonelli Andy , Keller Nick
Published: May 2018

The use of optical scattering to measure feature shape and dimensions, scatterometry, is now routine during semiconductor manufacturing. Scatterometry iteratively improves an optical model structure using simulations that are compared to experimental data from an ellipsometer. These simulations are done using the rigorous coupled wave analysis for solving Maxwell’s equations. In this article, we describe the Mueller matrix spectroscopic ellipsometry based scatterometry. Next, the rigorous coupled wave analysis for Maxwell’s equations is presented. Following this, several example measurements are described as they apply to specific process steps in the fabrication of gate-all-around (GAA) transistor structures. First, simulations of measurement sensitivity for the inner spacer etch back step of horizontal GAA transistor processing are described. Next, the simulated metrology sensitivity for sacrificial (dummy) amorphous silicon etch back step of vertical GAA transistor processing is discussed. Finally, we present the application of plasmonically active test structures for improving the sensitivity of the measurement of metal linewidths.
A new thermal conductivity probe for high temperature tests for the characterization of molten salts
Authors: Bovesecchi G. , Coppa P. , Pistacchio S.
Published: May 2018

A new thermal conductivity probe for high temperature (HT-TCP) has been built and tested. Its design and construction procedure are adapted from the ambient temperature thermal conductivity probe (AT-TCP) due to good performance of the latter device. The construction procedure and the preliminary tests are accurately described. The probe contains a Pt wire as a heater and a type K thermocouple (TC) as a temperature sensor, and its size is so small (0.6 mm in diameter and 60 mm in length) as to guarantee a length to diameter ratio of about 100. Calibration tests with glycerol for temperatures between 0 °C and 60 °C have shown good agreement with literature data, within 3%. Preliminary tests were also carried on a ternary molten salt for Concentrated Solar Power (CSP) (18% in mass of NaNO3, 52% KNO3, and 30% LiNO3) at 120 °C and 150 °C. Obtained results are within λ range of the Hitec® salt (53% KNO3, 7% NaNO3, 40% NaNO2). Unfortunately, at the higher temperature tested (200 °C), the viscosity of the salt highly decreases, and free convection starts, making the measurements unreliable.
An instrumented object for hand exercise and assessment using a pneumatic pressure sensor
Authors: Mohan A. , Tharion G. , Kumar R. K. , Devasahayam S. R.
Published: May 2018

Measurement of grip force is important for both exercise training and assessment of the hand during physical rehabilitation. The standard method uses a grip dynamometer which measures the force between the fingers and opposing thumb. The primary limitation of the grip dynamometer is the restriction of measurement to cylindrical grasps. Any deformation of the hand due to muscular or skeletal disease makes the grip dynamometer difficult or impossible to use. An alternative to the grip dynamometer is a sealed pneumatic object that can be gripped by the hand. Measurement of the internal pressure in the object can be related to the grip force. In this paper, we analyze such a pneumatic pressure sensing object for hand grip assessment and also describe an easy fabrication of the grip sensor. The instrumented object presented in this paper is designed to assess both the maximal voluntary grip forces and continuous grip force to monitor control of hand function during exercise under instruction from a therapist. Potential uses of such a pneumatic pressure sensing object for hand grip are in physical rehabilitation of patients following paralysing illnesses like stroke and spinal cord injury.
The effect of sampling techniques used in the multiconfigurational Ehrenfest method
Authors: Symonds C. , Kattirtzi J. A. , Shalashilin D. V.
Published: May 2018

In this paper, we compare and contrast basis set sampling techniques recently developed for use in the ab initio multiple cloning method, a direct dynamics extension to the multiconfigurational Ehrenfest approach, used recently for the quantum simulation of ultrafast photochemistry. We demonstrate that simultaneous use of basis set cloning and basis function trains can produce results which are converged to the exact quantum result. To demonstrate this, we employ these sampling methods in simulations of quantum dynamics in the spin boson model with a broad range of parameters and compare the results to accurate benchmarks.
Ferroelectricity in epitaxial Y-doped HfO2 thin film integrated on Si substrate
Authors: Lee K. , Lee T. Y. , Yang S. M. , Lee D. H. , Park J. , Chae S. C.
Published: May 2018

We report on the ferroelectricity of a Y-doped HfO2 thin film epitaxially grown on Si substrate, with an yttria-stabilized zirconia buffer layer pre-deposited on the substrate. Piezoresponse force microscopy results show the ferroelectric domain pattern, implying the existence of ferroelectricity in the epitaxial HfO2 film. The epitaxially stabilized HfO2 film in the form of a metal-ferroelectric-insulator-semiconductor structure exhibits ferroelectric hysteresis with a clear ferroelectric switching current in polarization-voltage measurements. The HfO2 thin film also demonstrates ferroelectric retention comparable to that of current perovskite-based metal-ferroelectric-insulator-semiconductor structures.
Self-contained in-vacuum in situ thin film stress measurement tool
Authors: Reinink J. , van de Kruijs R. W. E. , Bijkerk F.
Published: May 2018

A fully self-contained in-vacuum device for measuring thin film stress in situ is presented. The stress was measured by measuring the curvature of a cantilever on which the thin film was deposited. For this, a dual beam laser deflectometer was used. All optics and electronics needed to perform the measurement are placed inside a vacuum-compatible vessel with the form factor of the substrate holders of the deposition system used. The stand-alone nature of the setup allows the vessel to be moved inside a deposition system independently of optical or electronic feedthroughs while measuring continuously. A Mo/Si multilayer structure was analyzed to evaluate the performance of the setup. A radius of curvature resolution of 270 km was achieved. This allows small details of the stress development to be resolved, such as the interlayer formation between the layers and the amorphous-to-crystalline transition of the molybdenum which occurs at around 2 nm. The setup communicates with an external computer via a Wi-Fi connection. This wireless connection allows remote control over the acquisition and the live feedback of the measured stress. In principle, the vessel can act as a general metrology platform and add measurement capabilities to deposition setups with no modification to the deposition system.
Mitigation of X-ray shadow seeding of hydrodynamic instabilities on inertial confinement fusion capsules using a reduced diameter fuel fill-tube
Authors: MacPhee A. G. , Smalyuk V. A. , Landen O. L. , Weber C. R. , Robey H. F. , Alfonso E. L. , Biener J. , Bunn T. , Crippen J. W. , Farrell M. , Felker S. , Field J. E. , Hsing W. W. , Kong C. , Milovich J. , Moore A. , Nikroo A. , Rice N. , Stadermann M. , Wild C.
Published: May 2018

We report a reduced X-ray shadow imprint of hydrodynamic instabilities on the high-density carbon ablator surface of inertial confinement fusion (ICF) capsules using a reduced diameter fuel fill tube on the National Ignition Facility (NIF). The perturbation seed mass from hydrodynamic instabilities was reduced by approximately an order of magnitude by reducing both the diameter and wall thickness of the fill tube by ∼2×, consistent with analytical estimates. This work demonstrates a successful mitigation strategy for engineered features for ICF implosions on the NIF.
Loop-gap microwave resonator for hybrid quantum systems
Authors: Ball Jason R. , Yamashiro Yu , Sumiya Hitoshi , Onoda Shinobu , Ohshima Takeshi , Isoya Junichi , Konstantinov Denis , Kubo Yuimaru
Published: May 2018

We designed a loop-gap microwave resonator for applications of spin-based hybrid quantum systems and tested it with impurity spins in diamond. Strong coupling with ensembles of nitrogen-vacancy (NV) centers and substitutional nitrogen (P1) centers was observed. These results show that loop-gap resonators are viable in the prospect of spin-based hybrid quantum systems, especially for an ensemble quantum memory or a quantum transducer.
High-level theoretical characterization of the vinoxy radical (•CH2CHO) + O2 reaction
Authors: Weidman Jared D. , Allen Ryan T. , Moore Kevin B. , Schaefer Henry F.
Published: May 2018

Numerous processes in atmospheric and combustion chemistry produce the vinoxy radical (•CH2CHO). To understand the fate of this radical and to provide reliable energies needed for kinetic modeling of such processes, we have examined its reaction with O2 using highly reliable theoretical methods. Utilizing the focal point approach, the energetics of this reaction and subsequent reactions were obtained using coupled-cluster theory with single, double, and perturbative triple excitations [CCSD(T)] extrapolated to the complete basis set limit. These extrapolated energies were appended with several corrections including a treatment of full triples and connected quadruple excitations, i.e., CCSDT(Q). In addition, this study models the initial vinoxy radical + O2 reaction for the first time with multireference methods. We predict a barrier for this reaction of approximately 0.4 kcal mol−1. This result agrees with experimental findings but is in disagreement with previous theoretical studies. The vinoxy radical + O2 reaction produces a 2-oxoethylperoxy radical which can undergo a number of unimolecular reactions. Abstraction of a β-hydrogen (a 1,4-hydrogen shift) and dissociation back to reactants are predicted to be competitive to each other due to their similar barriers of 21.2 and 22.3 kcal mol−1, respectively. The minimum-energy β-hydrogen abstraction pathway produces a hydroperoxy radical (QOOH) that eventually decomposes to formaldehyde, CO, and •OH. Two other unimolecular reactions of the peroxy radical are α-hydrogen abstraction (38.7 kcal mol−1 barrier) and HO2• elimination (43.5 kcal mol−1 barrier). These pathways lead to glyoxal + •OH and ketene + HO2• formation, respectively, but they are expected to be uncompetitive due to their high barriers.
Single-shot femtosecond laser ablation of gold surface in air and isopropyl alcohol
Authors: Kudryashov S. I. , Saraeva I. N. , Lednev V. N. , Pershin S. M. , Rudenko A. A. , Ionin A. A.
Published: May 2018

Single-shot IR femtosecond-laser ablation of gold surfaces in ambient air and liquid isopropyl alcohol was studied by scanning electron microscopy characterization of crater topographies and time-resolved optical emission spectroscopy of ablative plumes in regimes, typical for non-filamentary and non-fragmentation laser production of nanoparticle sols. Despite one order of magnitude shorter (few nanoseconds) lifetimes and almost two orders of magnitude lower intensities of the quenched ablative plume emission in the alcohol ambient at the same peak laser fluence, craters for the dry and wet conditions appeared with rather similar nanofoam-like spallative topographies and the same thresholds. These facts envision the underlying surface spallation as one of the basic ablation mechanisms relevant for both dry and wet advanced femtosecond laser surface nano/micro-machining and texturing, as well as for high-throughput femtosecond laser ablative production of colloidal nanoparticles by MHz laser-pulse trains via their direct nanoscale jetting from the nanofoam in air and fluid environments.
Spherical harmonics and rigged Hilbert spaces
Authors: Celeghini E. , Gadella M. , del Olmo M. A.
Published: May 2018

This paper is devoted to study discrete and continuous bases for spaces supporting representations of SO(3) and SO(3, 2) where the spherical harmonics are involved. We show how discrete and continuous bases coexist on appropriate choices of rigged Hilbert spaces. We prove the continuity of relevant operators and the operators in the algebras spanned by them using appropriate topologies on our spaces. Finally, we discuss the properties of the functionals that form the continuous basis.
Light beam shaping for collimated emission from white organic light-emitting diodes using customized lenticular microlens arrays structure
Authors: Zhou Lei , Bai Gui-Lin , Guo Xin , Shen Su , Ou Qing-Dong , Fan Yuan-Yuan
Published: May 2018

We present a design approach to realizing a desired collimated planar incoherent light source (CPILS) by incorporating lenticular microlens arrays (LMLAs) onto the substrates of discrete white organic light-emitting diode (WOLED) light sources and demonstrate the effectiveness of this method in collimated light beam shaping and luminance enhancement simultaneously. The obtained collimated WOLED light source shows enhanced luminance by a factor of 2.7 compared with that of the flat conventional device at the normal polar angle and, more importantly, exhibits a narrowed angular emission with a full-width at half-maximum (FWHM) of ∼33.6°. We anticipate that the presented strategy could provide an alternative way for achieving the desired large scale CPILS, thereby opening the door to many potential applications, including LCD backlights, three-dimensional displays, car headlights, and so forth.
Observation of high-temperature bubbles in an ECR plasma
Authors: Terasaka K. , Yoshimura S. , Tanaka M. Y.
Published: May 2018

Creation and annihilation of high-temperature bubbles have been observed in an electron cyclotron resonance plasma. The electron temperature in the bubble core is three times higher than that in the ambient region, and the size perpendicular to the magnetic field is much smaller than the plasma diameter. Formation of a bubble accompanies large negative spikes in the floating potential of a Langmuir probe, and the spatiotemporal behavior of the bubble has been visualized with a high-impedance wire grid detector. It is found that the bubble is in a prolate spheroidal shape with the axis along the magnetic field and occurs randomly in time and independently in space.
Effects of surface plasma treatment on threshold voltage hysteresis and instability in metal-insulator-semiconductor (MIS) AlGaN/GaN heterostructure HEMTs
Authors: Zaidi Z. H. , Lee K. B. , Roberts J. W. , Guiney I. , Qian H. , Jiang S. , Cheong J. S. , Li P. , Wallis D. J. , Humphreys C. J. , Chalker P. R. , Houston P. A.
Published: May 2018

In a bid to understand the commonly observed hysteresis in the threshold voltage (VTH) in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors during forward gate bias stress, we have analyzed a series of measurements on devices with no surface treatment and with two different plasma treatments before the in-situ Al2O3 deposition. The observed changes between samples were quasi-equilibrium VTH, forward bias related VTH hysteresis, and electrical response to reverse bias stress. To explain these effects, a disorder induced gap state model, combined with a discrete level donor, at the dielectric/semiconductor interface was employed. Technology Computer-Aided Design modeling demonstrated the possible differences in the interface state distributions that could give a consistent explanation for the observations.
Reaction of N,N’-dimethylformamide and divalent viologen molecule to generate an organic dopant for molybdenum disulfide
Authors: Fukui A. , Miura K. , Ichimiya H. , Tsurusaki A. , Kariya K. , Yoshimura T. , Ashida A. , Fujimura N. , Kiriya D.
Published: May 2018

Tuning the carrier concentration is essential for semiconducting materials to apply optoelectronic devices. Molybdenum disulfide (MoS2) is a semiconducting material composed of atomically thin (∼0.7 nm thickness) layers. To dope thin MoS2, instead of using conventional atom/ion injection processes, a surface charge transfer method was successfully applied. In this study, we report a simple preparation method of a molecular dopant applicable to the doping process. The method follows a previous report for producing a molecular dopant, benzyl viologen (BV) which shows electron doping to MoS2. To prepare dopant BV molecules, a reduction process with a commercially available divalent BV by sodium borohydride (NaBH4) is required; however, the reaction requires a large consumption of NaBH4. NaBH4 drastically reacts with the solvent water itself. We found a reaction process of BV in an organic solvent, N,N’-dimethylformamide (DMF), by adding a small amount of water dissolving the divalent BV. The reaction is mild (at room temperature) and is autonomous once DMF comes into contact with the divalent BV aqueous solution. The reaction can be monitored with a UV-Vis spectrometer, and kinetic analysis indicates two reaction steps between divalent/monovalent/neutral viologen isomers. The product was soluble in toluene and did not dissolve in water, indicating it is similar to the reported dopant BV. The synthesized molecule was found to act as a dopant for MoS2 by applying a metal-oxide-semiconductor field-effect-transistor (MOSFET) structure. The process is a general method and applicable to other viologen-related dopants to tune the electronic structure of 2D materials to facilitate generating atomically thin devices.
Sharp acoustic vortex focusing by Fresnel-spiral zone plates
Authors: Jiménez Noé , Romero-García Vicent , García-Raffi Luis M. , Camarena Francisco , Staliunas Kestutis
Published: May 2018

We report the optimal focusing of acoustic vortex beams by using flat lenses based on a Fresnel-spiral diffraction grating. The flat lenses are designed by spiral-shaped Fresnel zone plates composed of one or several arms. The constructive and destructive interferences of the diffracted waves by the spiral grating result in sharp acoustic vortex beams, following the focal laws obtained in analogy with the Fresnel zone plate lenses. In addition, we show that the number of arms determines the topological charge of the vortex, allowing the precise manipulation of the acoustic wave field by flat lenses. The experimental results in the ultrasonic regime show excellent agreement with the theory and full-wave numerical simulations. A comparison with beam focusing by Archimedean spirals also showing vortex focusing is given. The results of this work may have potential applications for particle trapping, ultrasound therapy, imaging, or underwater acoustic transmitters.
Generation of radio vortex beams with designable polarization using anisotropic frequency selective surface
Authors: Yang Jin , Zhang Cheng , Ma Hui Feng , Zhao Jie , Dai Jun Yan , Yuan Wei , Yang Liu Xi , Cheng Qiang , Cui Tie Jun
Published: May 2018

We propose a strategy to convert a linearly polarized wave from a single point source to an orbital angular momentum (OAM) wave by arbitrary polarization via an anisotropic frequency selective surface (FSS) in the microwave frequency. By tailoring the geometries of FSS elements, reflection-phases in x and y polarizations are engineered and encoded independently, which allows us to design the eventual polarization state of the generated OAM vortex beam by elaborately selecting individual coding sequences for each polarization. Two types of FSSs are designed and experimentally characterized to demonstrate the capability of OAM generation with circular and linear polarizations, respectively, showing excellent performance in a wide bandwidth from 14 to 16 GHz. This method provides opportunities for polarization multiplexing in microwave OAM communication systems.
Ferroelectric negative capacitance domain dynamics
Authors: Hoffmann Michael , Khan Asif Islam , Serrao Claudy , Lu Zhongyuan , Salahuddin Sayeef , Pešić Milan , Slesazeck Stefan , Schroeder Uwe , Mikolajick Thomas
Published: May 2018

Transient negative capacitance effects in epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 capacitors are investigated with a focus on the dynamical switching behavior governed by domain nucleation and growth. Voltage pulses are applied to a series connection of the ferroelectric capacitor and a resistor to directly measure the ferroelectric negative capacitance during switching. A time-dependent Ginzburg-Landau approach is used to investigate the underlying domain dynamics. The transient negative capacitance is shown to originate from reverse domain nucleation and unrestricted domain growth. However, with the onset of domain coalescence, the capacitance becomes positive again. The persistence of the negative capacitance state is therefore limited by the speed of domain wall motion. By changing the applied electric field, capacitor area or external resistance, this domain wall velocity can be varied predictably over several orders of magnitude. Additionally, detailed insights into the intrinsic material properties of the ferroelectric are obtainable through these measurements. A new method for reliable extraction of the average negative capacitance of the ferroelectric is presented. Furthermore, a simple analytical model is developed, which accurately describes the negative capacitance transient time as a function of the material properties and the experimental boundary conditions.
Hydrogen passivation of poly-Si/SiOx contacts for Si solar cells using Al2O3 studied with deuterium
Authors: Schnabel Manuel , van de Loo Bas W. H. , Nemeth William , Macco Bart , Stradins Paul , Kessels W. M. M. , Young David L.
Published: May 2018

The interplay between hydrogenation and passivation of poly-Si/SiOx contacts to n-type Si wafers is studied using atomic layer deposited Al2O3 and anneals in forming gas and nitrogen. The poly-Si/SiOx stacks are prepared by thermal oxidation followed by thermal crystallization of a-Si:H films deposited by plasma-enhanced chemical vapor deposition. Implied open-circuit voltages as high as 710 mV are achieved for p-type poly-Si/SiOx contacts to n-type Si after hydrogenation. Correlating minority carrier lifetime data and secondary ion mass spectrometry profiles reveals that the main benefit of Al2O3 is derived from its role as a hydrogen source for chemically passivating defects at SiOx; Al2O3 layers are found to hydrogenate poly-Si/SiOx much better than a forming gas anneal. By labelling Al2O3 and the subsequent anneal with different hydrogen isotopes, it is found that Al2O3 exchanges most of its hydrogen with the ambient upon annealing at 400 °C for 1 h even though there is no significant net change in its total hydrogen content.
Milk performance and grazing behaviour of dairy cows in response to pasture allowance
Authors: Zanine A. M. , Motta G. P. R. , Ferreira D. J. , de Souza A. L. , Ribeiro M. D. , Geron L. J. V. , Fajardo M. , Sprunk M. , Pinho R. M. A.
Published: May 2018

This study aimed to evaluate the effects of pasture allowances on forage production, milk yield and composition, and grazing behaviour of Holstein cows during autumn. Thirty-six Holstein cows calving in the autumn were allocated to blocks considering: calving date, bodyweight, and body score. Treatments consisted of three pasture allowances as follows: high (HA; 38.4 kg DM/cow.day), medium (MA; 30.3 kg DM/cow.day), and low (LA; 26.8 kg DM/cow.day) pasture allowances. Forage mass and forage height pre-grazing were similar (P > 0.05) for all grazing targets. Pasture-use efficiency was affected (P < 0.05) by the pasture allowance. The highest and lowest efficiency was obtained with treatments LA and HA, respectively. The neutral detergent fibre content of forage harvesting was affected (P < 0.05) by the pasture allowance, with average of 44.8, 47.0, and 49.4 to HA, MA, and LA, respectively. There was an effect of pasture allowances (P < 0.05) on the milk yield per hectare and milk yield per cow. The highest production was observed in LA (438 L/ha.day) and the lowest in HA (314 L/ha.day). The percentage of milk fat, milk protein, and milk fat (g/cow.day) did not differ (P > 0.05) among pasture allowances. There was effect (P < 0.05) of pasture allowance with higher grazing time (369 min) and lower rumination time (23.3 min) observed to HA. Pasture allowances affected (P < 0.05) the total number of bites/day and bites/min, but did not affect (P > 0.05) bite mass. The pasture managements with low (26.8 kg DM/cow.day) pasture allowances provided better conditions for milk yield per area, likely due to the better grazing efficiency. However, pasture allowance provide little measurable changes on grazing behaviour.
Micronutrient seed priming improves stand establishment, grain yield and biofortification of bread wheat
Authors: Ali Nauman , Farooq Muhammad , Hassan Muhammad Ahmad , Arshad Muhammad Shakeel , Saleem Muhammad Kamran , Faran Muhammad
Published: May 2018

Agronomic biofortification by seed treatments is a convenient way to harvest improved yields of micronutrient-enriched grains. This 2-year field study was conducted to evaluate the effects of seed priming with zinc (Zn), boron (B) and manganese (Mn) alone and in combinations on stand establishment, grain yield and biofortification of bread wheat (Triticum aestivum L.). Seeds of wheat cv. Faisalabad-2008 were soaked in aerated solutions of 0.5 m Zn, 0.01 m B and 0.1 m Mn, alone and in different combinations, for 12 h. Seed priming with the micronutrients was quite effective in improving stand establishment, yield-contributing traits, grain yield, and straw and grain micronutrient contents during both years. Best stand establishment was achieved from seed priming with Zn+B, followed by seed priming with Zn+Mn. Grain yield improvement from different seed priming treatments was in the order Zn+B > Zn+Mn > Zn > B > Mn > Zn+B+Mn, with respective increases of 34%, 33%, 21%, 19%, 18% and 8% relative to untreated seeds. Seed priming with Zn, B and Mn alone and in combinations also improved the contents of the respective micronutrients in straw and grain. All seed priming treatments were economically profitable except Zn+B+Mn, which was not cost-effective. The highest benefit : cost ratio accrued from seed priming with Zn+B. In conclusion, seed priming with micronutrients was generally cost-effective in meeting the crop micronutrient requirements, and in improving crop stand, grain yield and grain micronutrient contents in bread wheat. Seed priming with Zn+B was the most effective in this regard.
Ultrafast nonthermal heating of water initiated by an X-ray Free-Electron Laser
Authors: Beyerlein Kenneth R. , Jönsson H. Olof , Alonso-Mori Roberto , Aquila Andrew , Bajt Saša , Barty Anton , Bean Richard , Koglin Jason E. , Messerschmidt Marc , Ragazzon Davide , Sokaras Dimosthenis , Williams Garth J. , Hau-Riege Stefan , Boutet Sébastien , Chapman Henry N. , Tîmneanu Nicuşor , Caleman Carl
Published: May 2018

Significance

X-ray Free-Electron Lasers have opened the door to a new era in structural biology, enabling imaging of biomolecules and dynamics that were impossible to access with conventional methods. A vast majority of imaging experiments, including Serial Femtosecond Crystallography, use a liquid jet to deliver the sample into the interaction region. We have observed structural changes in the carrying water during X-ray exposure, showing how it transforms from the liquid phase to a plasma. This ultrafast phase transition observed in water provides evidence that any biological structure exposed to these X-ray pulses is destroyed during the X-ray exposure.
Design of an allosterically modulated doxycycline and doxorubicin drug-binding protein
Authors: Schmidt Karin , Gardill Bernd R. , Kern Alina , Kirchweger Peter , Börsch Michael , Muller Yves A.
Published: May 2018

Significance

The design of binding sites for nonnatural ligands into natural proteins is a very topical subject in protein design. This also applies to the manipulation of allosteric coupling pathways with the goal of controlling protein function. Here it is shown that both topics can be addressed concurrently in a single protein. Thus, starting from human α1-antichymotrypsin, two drug-binding proteins were developed. Whereas ligand-binding design enables the binding of either the antibiotic doxycycline or the anticancer compound doxorubicin, the reengineering of an existing allosteric coupling mechanism enables the release of the bound ligands on occurrence of a proteinase trigger signal. It is proposed that such binding proteins can be further developed into drug-specific delivery shuttles.
Chemokine C-C motif ligand 33 is a key regulator of teleost fish barbel development
Authors: Zhou Tao , Li Ning , Jin Yulin , Zeng Qifan , Prabowo Wendy , Liu Yang , Tian Changxu , Bao Lisui , Liu Shikai , Yuan Zihao , Fu Qiang , Gao Sen , Gao Dongya , Dunham Rex , Shubin Neil H. , Liu Zhanjiang
Published: May 2018

Significance

Barbels are important sensory organs for food seeking of teleosts, reptiles, and amphibians, but the molecular basis of barbel development is unknown. Here, we exploited the barbel-less bottlenose catfish as a natural model to determine the genomic basis for barbel development. Through a series of comparative analyses using genome and transcriptome datasets, a chemokine gene,
ccl33
, was identified as a key regulator of barbel development. Its knockout in zebrafish led to the loss of barbels, further supporting the roles of
ccl33
for barbel development. These findings demand functional studies of chemokines as key developmental, as well as immune, regulators.
Triplets, birthweight, and handedness
Authors: Heikkilä Kauko , Van Beijsterveldt Catharina E. M. , Haukka Jari , Iivanainen Matti , Saari-Kemppainen Aulikki , Silventoinen Karri , Boomsma Dorret I. , Yokoyama Yoshie , Vuoksimaa Eero
Published: May 2018

Significance

Low birthweight is a risk factor for developmental delay, and is also associated with a higher odds of being left-handed. Likewise, compared with singletons, triplet births encompass an increased probability of left-handedness and developmental delay. In a large study, including triplets from two countries, we studied if left-handedness is associated with birthweight and postnatal development. Triplets have naturally low birthweights, being about 1.5 kg lighter than singletons. In both samples of triplets, we showed that left-handedness was associated with lower birthweight. Left-handers had also smaller infant head circumference and delayed motor development compared with right-handers, but these differences were not evident when controlling for birthweight.
Functional organization of intrinsic and feedback presynaptic inputs in the primary visual cortex
Authors: Zhang Qing-fang , Li Hao , Chen Ming , Guo Aike , Wen Yunqing , Poo Mu-ming
Published: May 2018

Significance

Elucidating how different types of presynaptic inputs to a brain area are functionally organized is crucial for understanding how incoming information is integrated. Here, we introduce presynaptic-targeted genetically encoded calcium indicators in two colors and mapped the functional organization of two major input pathways—primary visual cortex (V1) intrinsic and V2–V1 feedback—to tree shrew V1. Axon boutons of both input pathways are spatially organized according to their orientation preferences, forming orientation maps aligned to the V1 map. Nonselective integration of intrinsic inputs around dendritic trees reproduced neuronal orientation preference, suggesting a reinforcing role for intrinsic inputs to the neuronal map. Beyond the specific findings, the experimental approaches we introduced here could significantly expand the toolbox for exploring the organization of neural circuits.
Transhemispheric ecosystem disservices of pink salmon in a Pacific Ocean macrosystem
Authors: Springer Alan M. , van Vliet Gus B. , Bool Natalie , Crowley Mike , Fullagar Peter , Lea Mary-Anne , Monash Ross , Price Cassandra , Vertigan Caitlin , Woehler Eric J.
Published: May 2018

Significance

Ecological processes at regional geographic scales can be connected to those in far distant locations by teleconnections, or interactions between species and systems far removed from one another. Macrosystem ecology views such interactions as elements of much larger ecosystems than either component. We have identified a remarkable example of a transhemispheric macrosystem spanning 15,000 kilometers of the Pacific Ocean maintained by a migratory species of seabird that nests in the South Pacific and winters in the North Pacific. It highlights another example in a growing list of ecosystem disservices of an abundant species of North Pacific salmon, and the need to include ecosystem processes at such geographic scales in conservation and management considerations for this northern open ocean.
MDA-9/Syntenin regulates protective autophagy in anoikis-resistant glioma stem cells
Authors: Talukdar Sarmistha , Pradhan Anjan K. , Bhoopathi Praveen , Shen Xue-Ning , August Laura A. , Windle Jolene J. , Sarkar Devanand , Furnari Frank B. , Cavenee Webster K. , Das Swadesh K. , Emdad Luni , Fisher Paul B.
Published: May 2018

Significance

Gliomas exhibit high proportions of glioma stem cells (GSCs), anoikis resistance, increased brain parenchyma invasion, and resistance to therapy with high recurrence. GSCs display protective autophagy, a self-mediated lysosomal degradation process that balances sources of energy at critical times of stress. Protective autophagy in GSCs promotes resistance to anoikis, programmed death resulting from growth in an anchorage-independent manner. MDA-9 is critical in maintaining protective autophagy in GSCs, thereby contributing to anoikis-resistance. MDA-9 regulates critical molecules, including BCL2 and EGFR, which control autophagy. A link between MDA-9 and protective autophagy and anoikis-resistance identifies an Achilles’ heel of glioblastoma multiforme that may be exploited to define enhanced therapies with improved prognosis and decreased recurrence. Accordingly, targeting MDA-9 may represent a viable therapeutic strategy for glioblastoma multiforme.