bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes in Chest Wall Reconstruction Using Methyl Methacrylate Prostheses: A Review of the Literature and Case Series Utilizing a Novel Approach with Biologic Mesh
Authors: Shah Nikhil R. , Ayyala Haripriya S. , Tran Bao Ngoc N. , Therattil Paul J. , Keith Jonathan D.
Published: May 2019

Background Composite defects after chest wall resection may leave patients at risk with lack of protection of vital structures and potentially respiratory compromise secondary to flail segments. Reconstruction of the chest wall with various alloplastic materials is possible and well described. Here, the authors present a novel technique in chest wall reconstruction utilizing a methyl methacrylate (MMA) “sandwich” with biologic mesh. The authors also sought to determine outcomes in chest wall reconstruction with MMA to optimize surgical decision making and minimize patient morbidity.

Methods A literature review was conducted using MEDLINE and the Cochrane Collaboration Library for primary research articles on chest wall reconstruction using MMA. Data related to surgical techniques and patient outcomes were extracted and analyzed. The authors also present their case series and outcomes utilizing a novel technique with biologic mesh.

Results Seventy-four articles met inclusion criteria, which included a total of 562 patients. Reconstruction methods included three main variations of the MMA prosthesis and six institution-specific variations. Complications were reported in 13.7% of patients; the most common complications included infection (5.6%), respiratory failure (3.3%), and atelectasis (1.7%). Less commonly reported complications included prosthesis dislocation (1.2%), pneumonia (1.0%), and lung collapse (0.4%). Overall mortality due to respiratory causes was observed in nine patients (1.6%). In our case series, complications included respiratory failure and seroma was reported in one patient, with no complications at long-term follow-up.

Conclusion There are a variety of options available for rigid and nonrigid prosthetic repair of the chest wall. We present the first successful reported case series of reconstruction using biologic mesh as a component of the MMA sandwich prosthesis. MMA appears to be a safe and effective choice for rigid reconstruction when used alone or in conjunction with synthetic or biologic mesh.
Uniform-in-time transition from discrete to continuous dynamics in the Kuramoto synchronization
Authors: Ha Seung-Yeal , Kim Dohyun , Kim Jeongho , Zhang Xiongtao
Published: May 2019

Numerical simulations for continuous dynamical systems are based on their discretized models in time and space, and we take it for granted that the simulation results for the discrete dynamical systems as what is happening in the corresponding continuous dynamical systems. In general, this is valid in any finite time window under suitable conditions on system parameters. In this paper, we present a smooth transition from discrete dynamics to continuous dynamics for the ensemble of Kuramoto oscillators which is valid in the whole time interval by utilizing the exponential synchronization estimates and confining the initial phase in a compact set of the state space. We perform this uniform-in-time transition for the discrete Kuramoto model and its augmented second-order extension.
The Cauchy problem for the 1-D Gurevich-Zybin system
Authors: Thompson Ryan C.
Published: May 2019

In this paper, we prove well-posedness of the one dimensional Gurevich-Zybin system in Besov spaces Bp,rs. This will imply the existence and uniqueness of solutions in the aforementioned spaces along with the continuity of the data-to-solution map, provided that the initial data belong to Bp,rs. We also establish persistence properties of solutions by showing that strong solutions to the Gurevich-Zybin system decay at infinity in the spatial variable, provided that the initial data do. Furthermore, it is shown that the system exhibits finite speed of propagation in the sense that if the initial data are endowed with compact support, then the solution carries this support along particle trajectories. As a concluding note, we discuss blow-up criterion for solutions.
Different protonated states at the C-terminal of the amyloid-β peptide modulate the stability of S-shaped protofibril
Authors: Yin Xiuhua , Liu Shengtang , Perez-Aguilar Jose Manuel , Zhou Hong , Shao Qiwen , Yang Zaixing , Zhou Ruhong
Published: May 2019

Studies have found strong correlations between polymorphism and structural variations in amyloid-β (Aβ) fibrils and the diverse clinical subtypes of Alzheimer’s disease (AD). Thus, a detailed understanding of the conformational behavior of Aβ fibrils may be an aid to elucidate the pathological mechanisms involved in AD. However, a key point that has been inadvertently underestimated or dismissed is the role of the protonated state at the C-terminal residue of amyloid-β peptides, which can give rise to intrinsic differences in the morphology and stability of the fibrils. For instance, the effects of the salt bridge formed between the C-terminal residue A42 and the residue K28 on the S-shaped Aβ protofibril structure remain unknown and may be different from those in the U-shaped Aβ protofibril structures. To address this effect, we explore the stability of the S-shaped protofibrils capped with different C-terminal modifications, including carboxyl group in its deprotonated (COO−) and protonated (COOH) states, by using molecular dynamics simulations. Our findings indicated that the C-terminal deprotonated protofibril is significantly more stable than its C-terminal protonated counterpart due to a well-defined and highly stable zipper-like salt-bridge-chain formed by the ε-NH3+ groups on the sidechain of residue K28 and the C-terminal COO− group at the A42 residue. The revealed underlying molecular mechanism for the different stability of the protofibrils provides insights into the diversity of polymorphism in Aβ fibrils.
Performance verification of a precise vibrating-wire magnet alignment technique for next-generation light sources
Authors: Fukami K. , Azumi N. , Inoue S. , Kai T. , Kimura H. , Kiuchi J. , Matsui S. , Takano S. , Watanabe T. , Zhang C.
Published: May 2019

The high-accuracy alignment of magnets is a key issue in the development of next-generation light-source rings. To obtain adequate dynamic apertures, the magnets must be aligned to an accuracy of 10 µm or better. Recently, a new technique that utilizes a vibrating wire has attracted attention for this purpose as it can directly determine with high resolution the magnetic centers in a series of multipole magnets on a straight section between bending magnets. In conventional vibrating-wire alignment techniques, wire sag, which causes alignment errors, is determined from the theoretical catenary curve. By contrast, in the present study, we have measured the sag profiles of various wires in the longitudinal direction to micrometer-order accuracy. We concluded that we can reduce deviations of the actual wire sag from the theoretical curve by choosing a suitable wire. By setting up a test bench of a vibrating-wire alignment system for a series of multipole magnet on a straight section, we have achieved the total error of the magnetic-center measurements of micrometer-order in the standard deviation. Moreover, two systematic error factors, the drift of the magnetic centers due to thermal deformations of the magnets after they are excited and the change in the magnetic centers due to reassembly of the magnets after installing the vacuum chamber, are included in practical magnet alignments. We have experimentally investigated these error factors using the test bench.
Quantum theory of surface polariton Cherenkov light radiation source and its fluctuation
Authors: Yu C. , Liu S.
Published: May 2019

If the speed of the electron beam excited Surface Plasmon Polaritons (SPPs) exceeds the velocity of light in medium, Cherenkov radiation will be emitted. Here, on this important physical phenomenon, Surface Polariton Cherenkov Light Radiation Source (SPCLS), the quantum theory has been worked out. By this theory, the average field amplitude in SPCLS is obtained. The calculation results show that the quantum theory can explain the classical phenomena precisely and predict nonclassical excitation channels of photons that are based on the quantum nature of the electromagnetic field and the effect of SPPs. These excitation channels can be used to shorten the response time of Cherenkov detectors. The quantum theory also shows that SPCLS has a different fluctuation pattern compared with the ordinary electromagnetic systems where vacuum fluctuation dominates. The fluctuation pattern has two significant characteristics: first, the fluctuation of SPCLS will not vanish in the macroscopic case, which may draw theoretical and experimental interest; second, the fluctuation of SPCLS can be tuned by the velocity of the electron beam. Thus, the fluctuation of SPCLS can be used to enhance the radiation through stochastic resonance. Our investigation shows that important phenomena may be found out with the introduction of quantum theory in macroscopic electromagnetic problems.
A virtual stretch of light pulse interval by pulsed electron extraction introduced into a magnetic bottle electron spectrometer
Authors: Hikosaka Yasumasa
Published: May 2019

A pulsed extraction of electrons associated with a single light pulse is introduced into electron time-of-flight measurement by using a magnetic bottle electron spectrometer. The pulsed extraction enables us to observe long times-of-flight of electrons with synchrotron radiation pulses of short periods. The feasibility and the performance of this method are demonstrated by multielectron coincidence measurements for Xe 4d excitation/ionization.
Density functional theory of confined ionic liquids: A survey of the effects of ion type, molecular charge distribution, and surface adsorption
Authors: Kiratidis Adrian L. , Miklavcic Stanley J.
Published: May 2019

Ionic liquids confined between two planar charged walls are explored using density functional theory. The effort represents a study of the effects of the molecular structure, molecular charge distribution, and degree of surface adsorption on forces between the surfaces and on the inhomogeneous atom density profiles. Surface adsorption was found to significantly affect both the magnitude and sign of the surface forces, while differences in the distribution of molecular charge did not. On the other hand, different bulk densities were found to produce dramatically different surface forces indicating a difference in the degree of molecular packing at and near surfaces. No long-range forces were found in any of the cases considered. We conclude that in the absence of any specific cation-anion pairing, surface charges are effectively screened, and the surface forces are dominated by short ranged steric and dispersion interactions between adsorbed molecular layers. In many cases, very similar surface forces correspond to very different molecular arrangements, suggesting that unambiguous interpretation of measured surface forces in ionic liquids, in terms of molecular behavior, may be difficult to guarantee.
Linear stability analysis of a surfactant-laden shear-imposed falling film
Authors: Bhat Farooq Ahmad , Samanta Arghya
Published: May 2019

A study of the linear stability analysis of a shear-imposed fluid flowing down an inclined plane is performed when the free surface of the fluid is covered by an insoluble surfactant. The purpose is to extend the earlier work [H. H. Wei, “Effect of surfactant on the long-wave instability of a shear-imposed liquid flow down an inclined plane,” Phys. Fluids 17, 012103 (2005)] for disturbances of arbitrary wavenumbers. The Orr-Sommerfeld boundary value problem is formulated and solved numerically based on the Chebyshev spectral collocation method. Two temporal modes, the so-called surface mode and surfactant mode, are detected in the long-wave regime. The surfactant mode becomes unstable when the Péclet number exceeds its critical value. In fact, the instability of the surfactant mode occurs on account for the imposed shear stress. Energy budget analysis predicts that the kinetic energy of the infinitesimal disturbance grows with the imposed shear stress. On the other hand, the numerical results reveal that both surface and surfactant modes can be destabilized by increasing the value of the imposed shear stress. Similarly, it is demonstrated that the shear mode becomes more unstable in the presence of the imposed shear stress. However, it can be stabilized by incorporating the insoluble surfactant at the free surface. Apparently, it seems that inertia does not play any role in the surfactant mode in the moderate Reynolds number regime. Furthermore, the competition between surface and shear modes is discussed.
Conceptual design of a high-field septum magnet using a superconducting shield and a canted-cosine-theta magnet
Authors: Barna Dániel , Novák Martin , Brunner Kristóf , Kirby Glyn , Goddard Brennan , Borburgh Jan , Atanasov Miroslav Georgiev , Sanz Ull Alejandro , Renner Elisabeth , Bartmann Wolfgang , Szakály Marcell
Published: May 2019

A zero-field cooled superconducting shield was previously proposed to realize a high-field (at least 3 T) septum magnet for the Future Circular Collider proton-proton ring. In this paper, we present the conceptual design of a complete septum magnet prototype including a shield with an optimized shape and a simple and cost-effective superconducting magnet using the canted cosine theta concept. 2D optimization of the coil geometry and a realistic 2D simulation of the fieldmap and field homogeneity are presented taking into account the nonlinear penetration of the magnetic field into the shield.
Counter-propagating wave packets in the quantum transition state approach to reactive scattering
Authors: Zhao Bin , Manthe Uwe
Published: May 2019

The quantum transition state concept provides an intuitive and numerically efficient framework for the description of quantum state-resolved reactive scattering and thermal reaction processes. Combining multiconfigurational time-dependent Hartree wave packet dynamics calculations with a flux correlation function based analysis, rigorous full-dimensional calculations of initial state-selected and state-to-state reaction probabilities for six atom reactions are feasible. In these calculations, a set of wave packets is generated in the transition state region, propagated into the asymptotic area, and analyzed. In the present work, an alternative approach which employs counter-propagating sets of wave packets is introduced. Outgoing wave packets started in the transition state region are matched with incoming wave packets generated in the reactant (or product) asymptotic area. Studying the H + CH4 → H2 + CH3 reaction as a prototypical example, one finds that the incoming wave packets can be propagated closely up to the transition state region with minor numerical effort. Employing cross correlation functions of incoming and outgoing wavefunctions, the propagation times required for the outgoing wave packet and thus the numerical costs of the entire calculation can be reduced significantly. Detailed full-dimensional calculations studying initial state-selected reaction probabilities for the H + CH4 → H2 + CH3 reaction are presented to illustrate the new approach. It is found that converged results can be obtained using shorter propagation times of the outgoing wave packets and less single-particle functions.
Progress towards achieving fusion ignition at NIF
Authors: Kim Meeri
Published: May 2019

New article describes recent progress as well as what still needs to happen to achieve fusion ignition at the National Ignition Facility.
Advanced cloud motion tracking increases solar forecasting accuracy
Authors: Patrick Chris
Published: May 2019

Authors introduce a model that extracts dynamic features from sky images to improve solar forecasting.
Crystal structures of Ca
2+
–calmodulin bound to Na
V
C-terminal regions suggest role for EF-hand domain in binding and inactivation
Authors: Gardill Bernd R. , Rivera-Acevedo Ricardo E. , Tung Ching-Chieh , Van Petegem Filip
Published: May 2019

Voltage-gated sodium (Na
V
) and calcium channels (Ca
V
) form targets for calmodulin (CaM), which affects channel inactivation properties. A major interaction site for CaM resides in the C-terminal (CT) region, consisting of an IQ domain downstream of an EF-hand domain. We present a crystal structure of fully Ca
2+
-occupied CaM, bound to the CT of Na
V
1.5. The structure shows that the C-terminal lobe binds to a site ∼90° rotated relative to a previous site reported for an apoCaM complex with the Na
V
1.5 CT and for ternary complexes containing fibroblast growth factor homologous factors (FHF). We show that the binding of FHFs forces the EF-hand domain in a conformation that does not allow binding of the Ca
2+
-occupied C-lobe of CaM. These observations highlight the central role of the EF-hand domain in modulating the binding mode of CaM. The binding sites for Ca
2+
-free and Ca
2+
-occupied CaM contain targets for mutations linked to long-QT syndrome, a type of inherited arrhythmia. The related Na
V
1.4 channel has been shown to undergo Ca
2+
-dependent inactivation (CDI) akin to Ca
V
s. We present a crystal structure of Ca
2+
/CaM bound to the Na
V
1.4 IQ domain, which shows a binding mode that would clash with the EF-hand domain. We postulate the relative reorientation of the EF-hand domain and the IQ domain as a possible conformational switch that underlies CDI.
Single steel strut mechanical testing: Challenges and future research directions
Authors: Kaya Ali Can , Zaslansky Paul , Fischer Sebastian , Fleck Claudia
Published: May 2019

Open-cell stainless steel foams, composed of hollow struts, are excellent candidates for energy absorption and thermo-mechanical applications. The basic mechanical element responsible for the function of these foams is the single strut. However, testing and characterisation of single foam struts to predict the foam strength have stirred up a new debate about approaches to micro-tensile testing of such elements. In this paper, we present a protocol for in-situ micro-tensile testing of hollow steel struts using a custom-made grip system. The adapted grips make it possible to perform analysis of the deformation of multiple sintered struts. Here we present and discuss challenges encountered during such micro-tensile testing of hollow steel struts.
Digital image correlation for strain measurement in plastic film blowing process
Authors: Muniandy Komethi
Published: May 2019

Surface deformation study of a polymer film during plastic film blowing (PFB) extrusion process though is considered essential, is difficult to execute as the process is fast and continuous. Digital image correlation (DIC) is an optical technique that is non-destructive, highly accurate and designed to measure deformations from micro to macro scale. DIC can be proposed as a reliable tool to understand the relationship of polymer structure-processing-properties. In this literature, digital image correlation, its basic principle of operation and reliability guided DIC for continuous large deformation are comprehensively explored. Versatility of DIC, and the conditions that affect the measurement algorithm as well as preceding use of DIC in polymer processes are reviewed. The implementation and potential use of DIC in PFB are described.

This review was submitted as part of the 2019 Materials Literature Review Prize of the Institute of Materials, Minerals and Mining run by the Editorial Board of MST. Sponsorship of the prize by TWI Ltd is gratefully acknowledged.
Strain rate dependence of the indentation size effect in Ti–10V–2Fe–3Al alloy
Authors: Ma Xinkai , Li Fuguo , Sun Zhankun , Hou Junhua , Li Jinghui , Fang Xiaotian
Published: May 2019

The influence of strain rates on the indentation size effect (ISE) was explored experimentally. A strong ISE phenomenon on the hardness of Ti–10V–2Fe–3Al (Ti-1023) alloy was found when the peak-load was less than 3500 mN, regardless of the variation of loading rates. However, as indenter strain rates increased, the degree of ISE reduced considerably, which was related to the decrease of the internal indentation length scale ranging from 23.08 to 6.80 µm. Furthermore, a positive strain rate sensitivity of the hardness in the whole peak-load range was found in Ti-1023 alloy, which showed a linear function of indenter load. The underlying mechanism was well explained by the variation of geometrically necessary dislocation and statistically stored dislocations in Ti-1023 alloy.
Human lymphoid organ cDC2 and macrophages play complementary roles in T follicular helper responses
Authors: Durand Mélanie , Walter Thomas , Pirnay Tiphène , Naessens Thomas , Gueguen Paul , Goudot Christel , Lameiras Sonia , Chang Qing , Talaei Nafiseh , Ornatsky Olga , Vassilevskaia Tatiana , Baulande Sylvain , Amigorena Sebastian , Segura Elodie
Published: May 2019

CD4+ T follicular helper (Tfh) cells are essential for inducing efficient humoral responses. T helper polarization is classically orientated by dendritic cells (DCs), which are composed of several subpopulations with distinct functions. Whether human DC subsets display functional specialization for Tfh polarization remains unclear. Here we find that tonsil cDC2 and CD14+ macrophages are the best inducers of Tfh polarization. This ability is intrinsic to the cDC2 lineage but tissue dependent for macrophages. We further show that human Tfh cells comprise two effector states producing either IL-21 or CXCL13. Distinct mechanisms drive the production of Tfh effector molecules, involving IL-12p70 for IL-21 and activin A and TGFβ for CXCL13. Finally, using imaging mass cytometry, we find that tonsil CD14+ macrophages localize in situ in the B cell follicles, where they can interact with Tfh cells. Our results indicate that human lymphoid organ cDC2 and macrophages play complementary roles in the induction of Tfh responses.
Heart rate variability categories of fluctuation amplitude and complexity: diagnostic markers of fetal development and its disturbances
Authors: Hoyer Dirk , Schmidt Alexander , Gustafson Kathleen M , Lobmaier Silvia M , Lakhno Igor , van Leeuwen Peter , Cysarz Dirk , Preisl Hubert , Schneider Uwe
Published: May 2019

Objective: In fetal diagnosis the myriad and diversity of heart rate variability (HRV) indices prevents a comparable routine evaluation of disturbances in fetal development and well-being. The work aims at the extraction of a small set of HRV key indices that could help to establish a universal, overarching tool to screen for any disturbance. Approach: HRV indices were organized in categories of short-term (prefix s) and long-term (prefix l) amplitude fluctuations (AMP), complexity (COMP), and patterns (PATTERN) and common representatives for each category were extracted. This procedure was done with respect to the diagnostic value in the evaluation of the maturation age throughout the second and complete third trimester of pregnancy as well as to potential differences associated with maternal life-style factors (physical exercise, smoking), nutrient intervention (docosahexaenoic acid (DHA) supplementation), and complications of pregnancy (gestational diabetes mellitus (GDM), intra-uterine growth restriction (IUGR)). Main results: We found a comprehensive minimal set that includes [lAMP: short term variation (STV), initially introduced in cardiotocography, sAMP: heart rate increase across one interbeat interval of phase rectified averaged signal - acceleration capacity (ACst1), lCOMP: scale 4 multi-scale entropy (MSE4), PATTERN: skewness] for the maturation age prediction, and partly overlapping [lAMP: STV, sAMP: ACst1, sCOMP: Lempel Ziv complexity (LZC)] for the discrimination of the deviations. Significance: The minimal set of category-based HRV representatives allows for a screening of fetal development and well-being. These results are an important step towards a universal and comparable diagnostic tool for the early identification of developmental disturbances.

Novelty & Significance

Fetal development and its disturbances have been reported to be associated with a multiplicity of HRV indices. Furthermore, these HRV indices change with maturation. We propose the abstraction of HRV categories defined by short- and long-term fluctuation amplitude, complexity, and pattern indices that cover all relevant aspects of maturational age, behavioral influences and a series of pathological disturbances. The study data are provided by multiple centers. Our approach is an important step towards the goal of a standardized diagnostic tool for early identification of fetal developmental disturbances with respect to the reduction of serious complications in the later life.
Effect of an eight-week smartphone-guided HRV-biofeedback intervention on autonomic function and impulsivity in healthy controls
Authors: Schumann Andy , Köhler Stefanie , Brotte Lisa , Bär Karl-Jürgen
Published: May 2019

A large body of scientific studies suggest a close relationship between increased vagal function and better cognitive performance. Objective: In the current study, we investigated the association between autonomic function and behavioral impulsivity. We hypothesized that heart rate variability (HRV) biofeedback training increases HRV and enhances inhibitory control. Approach: A total of 28 healthy participants were recruited. After drop-out, 14 participants completed an eight-week HRV biofeedback training with five training sessions per week including one session at the clinic’s laboratory and four sessions at home using a mobile application running on their smartphone. Ten control subjects matched with respect to age and gender played a mobile game according to the same schedule as the biofeedback group. The assessment of autonomic status and the stop-signal task were conducted before the beginning of the training (T1) and after finishing the schedule (T2). Main results: We found a relationship of reaction times in the stop-signal task and standard HRV as well as cardiorespiratory indices. After biofeedback training, short-term HRV and baroreflex function significantly increased by 33% (CI [2%, 64%], p   <  0.05) and 21% (CI [5%, 36%], p   <  0.05), respectively. The performance in the stop-signal task was not affected by the biofeedback intervention. Compared to the changes of autonomic indices in the control group, only a decrease of skin conductance levels in the biofeedback group remained statistically significant. Significance: Our results indicate that a smartphone-based HRV biofeedback intervention can be applied to improve cardiovagal function in healthy subjects. Although higher HRV was associated with higher levels of inhibitory control, HRV biofeedback had no effect on measures of impulsivity.
Precision photonic integration for future large-scale photonic integrated circuits
Authors: Chen Xiangfei
Published: May 2019

Ruiqin Jin talks to Xiangfei Chen about the importance of this growing field
Multi-channel 28-GHz millimeter-wave signal generation on a silicon photonic chip with automated polarization control
Authors: Cao Ruiyuan , He Yu , Zhu Qingming , Li Jingchi , An Shaohua , Zhang Yong , Su Yikai
Published: May 2019

We propose and experimentally demonstrate an integrated silicon photonic scheme to generate multi-channel millimeter-wave (MMW) signals for 5G multi-user applications. The fabricated silicon photonic chip has a footprint of 1.1 × 2.1 mm2 and integrates 7 independent channels each having on-chip polarization control and heterodyne mixing functions. 7 channels of 4-Gb/s QPSK baseband signals are delivered via a 2-km multi-core fiber (MCF) and coupled into the chip with a local oscillator (LO) light. The polarization state of each signal light is automatically adjusted and aligned with that of the LO light, and then 7 channels of 28-GHz MMW carrying 4-Gb/s QPSK signals are generated by optical heterodyne beating. Automated polarization-control function of each channel is also demonstrated with ~7-ms tuning time and ~27-dB extinction ratio.
Research for radiation-hardened high-voltage SOI LDMOS
Authors: Li Yanfei , Zhu Shaoli , Wu Jianwei , Hong Genshen , Xu Zheng
Published: May 2019

Based on the silicon-on-insulator (SOI) technology and radiation-hardened silicon gate (RSG) process, a radiation-hardened high-voltage lateral double-diffused MOSFET (LDMOS) device is presented in this paper. With the gate supply voltage of 30 V, the LDMOS device has a gate oxide thickness of 120 nm, and the RSG process is effective in reducing the total ionizing dose (TID) radiation-induced threshold voltage shift. The p-type ion implantation process and gate-enclosed layout topology are used to prevent radiation-induced leakage current through a parasitic path under the bird's beak and at the deep trench corner, and the device is compatible with high-voltage SOI CMOS process. In the proposed LDMOS, the total ionizing dose radiation degradation for the ON bias is more sensitive than the OFF bias. The experiment results show that the SOI LDMOS has a negative threshold voltage shift of 1.12 V, breakdown voltage of 135 V, and off-state leakage current of 0.92 pA/μm at an accumulated dose level of 100 krad (Si).
Design and analysis of a NMOS triggered LIGBT structure for electrostatic discharge protection
Authors: Tian Li , Cheng Jianbing , Zhang Cairong , Shen Li , Wang Lei
Published: May 2019

A novel NMOS triggered LIGBT (NTLIGBT) structure is proposed for electrostatic discharge (ESD) protection in this paper. The structure utilizes internal NMOS to trigger SCR-like structure in LIGBT. The trigger voltage is significantly reduced because the embedded NMOS causes N+-drain/P-body junction being apt to avalanche breakdown. At the same time, the new parasitic PNP transistor including the newly added P+-region as a collector forms another path to bleed ESD current and then the conductivity modulation in the LIGBT is weakened. As a result, the holding voltage is increased. So, the proposed NTLIGBT structure has a narrow ESD design window. The simulation results show an improvement of 71.5% in trigger voltage and over 50% in holding voltage comparing with the conventional LIGBT structure.
Realizing super-long Cu2O nanowires arrays for high-efficient water splitting applications with a convenient approach
Authors: Nasori Nasori , Dai Tianyi , Jia Xiaohao , Rubiyanto Agus , Cao Dawei , Qu Shengchun , Wang Zhanguo , Wang Zhijie , Lei Yong
Published: May 2019

Nanowire (NW) structures is an alternative candidate for constructing the next generation photoelectrochemical water splitting system, due to the outstanding optical and electrical properties. NW photoelectrodes comparing to traditional semiconductor photoelectrodes shows the comparatively shorter transfer distance of photo-induced carriers and the increase amount of the surface reaction sites, which is beneficial for lowering the recombination probability of charge carriers and improving their photoelectrochemical (PEC) performances. Here, we demonstrate for the first time that super-long Cu2O NWs, more than 4.5 μm, with highly efficient water splitting performance, were synthesized using a cost-effective anodic alumina oxide (AAO) template method. In comparison with the photocathode with planar Cu2O films, the photocathode with Cu2O NWs demonstrates a significant enhancement in photocurrent, from –1.00 to –2.75 mA/cm2 at –0.8 V versus Ag/AgCl. After optimization of the photoelectrochemical electrode through depositing Pt NPs with atomic layer deposition (ALD) technology on the Cu2O NWs, the plateau of photocurrent has been enlarged to –7 mA/cm2 with the external quantum yield up to 34% at 410 nm. This study suggests that the photoelectrode based on Cu2O NWs is a hopeful system for establishing high-efficiency water splitting system under visible light.
Effects of V-pits covering layer position on the optoelectronic performance of InGaN green LEDs
Authors: Xu Chen , Zheng Changda , Wu Xiaoming , Pan Shuan , Jiang Xingan , Liu Junlin , Jiang Fengyi
Published: May 2019

The impact of the V-pits covering layer (VCL) position on the optoelectronic performance of InGaN-based green light-emitting diodes (LEDs) was investigated. It is found that earlier covering of V-pits will hinder the hole injection via the sidewall of V-pits, and then result in less quantum wells (QWs) participating in radioluminescence. The current-voltage characteristics show that the LEDs with earlier covering of V-pits have higher operating voltage at room temperature, and a more dramatic voltage rise with the reduction of temperature. Meanwhile, more manifested emission peaks for sidewall QWs and deeper QWs near to n-type layer was observed in the sample with earlier coveing of V-pits at cryogenic temperatures, for the reason that the holes being injected via V-pits sidewall have higher kinetic energy and could transport to deeper QWs.
A novel 4H-SiC trench MOSFET with double shielding structures and ultralow gate-drain charge
Authors: Luo Xiaorong , Liao Tian , Wei Jie , Fang Jian , Yang Fei , Zhang Bo
Published: May 2019

A new ultralow gate–drain charge (Q
GD) 4H-SiC trench MOSFET is presented and its mechanism is investigated by simulation. The novel MOSFET features double shielding structures (DS-MOS): one is the grounded split gate (SG), the other is the P+ shielding region (PSR). Both the SG and the PSR reduce the coupling effect between the gate and the drain, and transform the most part of the gate–drain capacitance (C
GD) into the gate–source capacitance (C
GS) and drain–source capacitance (C
DS) in series. Thus the C
GD is reduced and the proposed DS-MOS obtains ultralow Q
GD. Compared with the double-trench MOSFET (DT-MOS) and the conventional trench MOSFET (CT-MOS), the proposed DS-MOS decreases the Q
GD by 85% and 81%, respectively. Moreover, the figure of merit (FOM), defined as the product of specific on-resistance (R
on, sp) and Q
GD (R
on, sp
Q
GD), is reduced by 84% and 81%, respectively.
A novel design approach of charge plasma tunnel FET for radio frequency applications
Authors: Yadav Shivendra , Pamnani Alish , Sharma Dheeraj , Gedam Anju , Kumar Atul , Sharma Neeraj
Published: May 2019

In this paper, the impact of extra electron source (EES) and dual metal gate engineering on conventional charge plasma TFET (CP-TFET) have been done for improving DC and analog/RF parameters. CP-TFET structure is upgraded to double source CP-TFET (DS-CP-TFET) by placing an EES below the source/channel junction for enhancing the device performance in terms of driving current and RF figures of merit (FOMs). But, in spite of these pros, the approach is having cons of higher leakage current similar to MOSFET and negative conductance (inherent nature of TFET). Both the issues have been resolved in the double source dual gate CP-TFET (DS-DG-CP-TFET) by gate workfunction engineering and drain underlapping respectively. Additionally, for getting the optimum performance of DS-DG-CP-TFET, the device sensitivity has been investigated in terms of position of EES, length of drain electrode and workfunction of gate electrode 1 (GE1).
Realistic volumetric-approach to simulate transcranial electric stimulation—ROAST—a fully automated open-source pipeline
Authors: Huang Yu , Datta Abhishek , Bikson Marom , Parra Lucas C
Published: May 2019

Objective. Research in the area of transcranial electrical stimulation (TES) often relies on computational models of current flow in the brain. Models are built based on magnetic resonance images (MRI) of the human head to capture detailed individual anatomy. To simulate current flow on an individual, the subject’s MRI is segmented, virtual electrodes are placed on this anatomical model, the volume is tessellated into a mesh, and a finite element model (FEM) is solved numerically to estimate the current flow. Various software tools are available for each of these steps, as well as processing pipelines that connect these tools for automated or semi-automated processing. The goal of the present tool—realistic volumetric-approach to simulate transcranial electric simulation (ROAST)—is to provide an end-to-end pipeline that can automatically process individual heads with realistic volumetric anatomy leveraging open-source software and custom scripts to improve segmentation and execute electrode placement. Approach. ROAST combines the segmentation algorithm of SPM12, a Matlab script for touch-up and automatic electrode placement, the finite element mesher iso2mesh and the solver getDP. We compared its performance with commercial FEM software, and SimNIBS, a well-established open-source modeling pipeline. Main results. The electric fields estimated with ROAST differ little from the results obtained with commercial meshing and FEM solving software. We also do not find large differences between the various automated segmentation methods used by ROAST and SimNIBS. We do find bigger differences when volumetric segmentation are converted into surfaces in SimNIBS. However, evaluation on intracranial recordings from human subjects suggests that ROAST and SimNIBS are not significantly different in predicting field distribution, provided that users have detailed knowledge of SimNIBS. Significance. We hope that the detailed comparisons presented here of various choices in this modeling pipeline can provide guidance for future tool development. We released ROAST as an open-source, easy-to-install and fully-automated pipeline for individualized TES modeling.
Immunohistochemical and Ultrastructural Features of Hepatocellular Cytoplasmic Globules in Venous Outflow Impairment
Authors: Buglioni Alessia , Wu Tsung-Teh , Mounajjed Taofic
Published: May 2019

Objectives

To examine the immunohistochemical and ultrastructural features of hepatocellular cytoplasmic globules in venous outflow impairment (VOI).

Methods

Sixty-four liver core biopsies were screened. Patients with α-1 antitrypsin (AAT) deficiency were excluded. All biopsies were stained with H&E, Masson trichrome, periodic acid-Schiff with diastase digestion (PAS-D), phosphotungstic acid hematoxylin (PTAH), complement protein 4d (C4d) immunostain, and AAT immunostain. Electron microscopy was also performed.

Results

Hepatocellular globules were identified in 8% of in-house cases. Causes of VOI included heart failure and Budd-Chiari syndrome. The hepatocellular cytoplasmic globules showed size variability, random distribution, and positivity for PAS-D, PTAH, and AAT. C4d was inconsistently positive. Electron microscopy showed that the globules were lysosome-bound inclusions containing microfibrillar material and fibrinogen.

Conclusions

PAS-D–positive hepatocellular globules occur in VOI. They cross-react with AAT but have different appearance, localization, and ultrastructural composition from globules in AAT deficiency.
Ambient Fine Particulate Matter and Preterm Birth in California: Identification of Critical Exposure Windows
Authors: Sheridan Paige , Ilango Sindana , Bruckner Tim A , Wang Qiong , Basu Rupa , Benmarhnia Tarik
Published: May 2019

Exposure to ambient fine particulate matter (particulate matter ≤2.5 μm in aerodynamic diameter (PM2.5)) during pregnancy is associated with preterm birth (PTB), a leading cause of infant morbidity and mortality. Results from studies attempting to identify etiologically relevant exposure periods of vulnerability have been inconsistent, possibly because of failure to consider the time-to-event nature of the outcome and lagged exposure effects of PM2.5. In this study, we aimed to identify critical exposure windows for weekly PM2.5 exposure and PTB in California using California birth cohort data from 2005–2010. Associations were assessed using distributed-lag Cox proportional hazards models. We assessed effect-measure modification by race/ethnicity by calculating the weekly relative excess risk due to interaction. For a 10-μg/m3 increase in PM2.5 exposure over the entire period of gestation, PTB risk increased by 11% (hazard ratio = 1.11, 95% confidence interval: 1.09, 1.14). Gestational weeks 17–24 and 36 were associated with increased vulnerability to PM2.5 exposure. We find that non-Hispanic black mothers may be more susceptible to effects of PM2.5 exposure than non-Hispanic white mothers, particularly at the end of pregnancy. These findings extend our knowledge about the existence of specific exposure periods during pregnancy that have the greatest impact on preterm birth.
Methodological Challenges When Studying Distance to Care as an Exposure in Health Research
Authors: Caniglia Ellen C , Zash Rebecca , Swanson Sonja A , Wirth Kathleen E , Diseko Modiegi , Mayondi Gloria , Lockman Shahin , Mmalane Mompati , Makhema Joseph , Dryden-Peterson Scott , Kponee-Shovein Kalé Z , John Oaitse , Murray Eleanor J , Shapiro Roger L
Published: May 2019

Distance to care is a common exposure and proposed instrumental variable in health research, but it is vulnerable to violations of fundamental identifiability conditions for causal inference. We used data collected from the Botswana Birth Outcomes Surveillance study between 2014 and 2016 to outline 4 challenges and potential biases when using distance to care as an exposure and as a proposed instrument: selection bias, unmeasured confounding, lack of sufficiently well-defined interventions, and measurement error. We describe how these issues can arise, and we propose sensitivity analyses for estimating the degree of bias.
PRISM: methylation pattern-based, reference-free inference of subclonal makeup
Authors: Lee Dohoon , Lee Sangseon , Kim Sun
Published: May 2019

Motivation

Characterizing cancer subclones is crucial for the ultimate conquest of cancer. Thus, a number of bioinformatic tools have been developed to infer heterogeneous tumor populations based on genomic signatures such as mutations and copy number variations. Despite accumulating evidence for the significance of global DNA methylation reprogramming in certain cancer types including myeloid malignancies, none of the bioinformatic tools are designed to exploit subclonally reprogrammed methylation patterns to reveal constituent populations of a tumor. In accordance with the notion of global methylation reprogramming, our preliminary observations on acute myeloid leukemia (AML) samples implied the existence of subclonally occurring focal methylation aberrance throughout the genome.

Results

We present PRISM, a tool for inferring the composition of epigenetically distinct subclones of a tumor solely from methylation patterns obtained by reduced representation bisulfite sequencing. PRISM adopts DNA methyltransferase 1-like hidden Markov model-based in silico proofreading for the correction of erroneous methylation patterns. With error-corrected methylation patterns, PRISM focuses on a short individual genomic region harboring dichotomous patterns that can be split into fully methylated and unmethylated patterns. Frequencies of such two patterns form a sufficient statistic for subclonal abundance. A set of statistics collected from each genomic region is modeled with a beta-binomial mixture. Fitting the mixture with expectation-maximization algorithm finally provides inferred composition of subclones. Applying PRISM for two AML samples, we demonstrate that PRISM could infer the evolutionary history of malignant samples from an epigenetic point of view.

Availability and implementation

PRISM is freely available on GitHub (https://github.com/dohlee/prism).

Supplementary information

Supplementary data are available at Bioinformatics online.
Block HSIC Lasso: model-free biomarker detection for ultra-high dimensional data
Authors: Climente-González Héctor , Azencott Chloé-Agathe , Kaski Samuel , Yamada Makoto
Published: May 2019

Motivation

Finding non-linear relationships between biomolecules and a biological outcome is computationally expensive and statistically challenging. Existing methods have important drawbacks, including among others lack of parsimony, non-convexity and computational overhead. Here we propose block HSIC Lasso, a non-linear feature selector that does not present the previous drawbacks.

Results

We compare block HSIC Lasso to other state-of-the-art feature selection techniques in both synthetic and real data, including experiments over three common types of genomic data: gene-expression microarrays, single-cell RNA sequencing and genome-wide association studies. In all cases, we observe that features selected by block HSIC Lasso retain more information about the underlying biology than those selected by other techniques. As a proof of concept, we applied block HSIC Lasso to a single-cell RNA sequencing experiment on mouse hippocampus. We discovered that many genes linked in the past to brain development and function are involved in the biological differences between the types of neurons.

Availability and implementation

Block HSIC Lasso is implemented in the Python 2/3 package pyHSICLasso, available on PyPI. Source code is available on GitHub (https://github.com/riken-aip/pyHSICLasso).

Supplementary information

Supplementary data are available at Bioinformatics online.
Deep learning with multimodal representation for pancancer prognosis prediction
Authors: Cheerla Anika , Gevaert Olivier
Published: May 2019

Motivation

Estimating the future course of patients with cancer lesions is invaluable to physicians; however, current clinical methods fail to effectively use the vast amount of multimodal data that is available for cancer patients. To tackle this problem, we constructed a multimodal neural network-based model to predict the survival of patients for 20 different cancer types using clinical data, mRNA expression data, microRNA expression data and histopathology whole slide images (WSIs). We developed an unsupervised encoder to compress these four data modalities into a single feature vector for each patient, handling missing data through a resilient, multimodal dropout method. Encoding methods were tailored to each data type—using deep highway networks to extract features from clinical and genomic data, and convolutional neural networks to extract features from WSIs.

Results

We used pancancer data to train these feature encodings and predict single cancer and pancancer overall survival, achieving a C-index of 0.78 overall. This work shows that it is possible to build a pancancer model for prognosis that also predicts prognosis in single cancer sites. Furthermore, our model handles multiple data modalities, efficiently analyzes WSIs and represents patient multimodal data flexibly into an unsupervised, informative representation. We thus present a powerful automated tool to accurately determine prognosis, a key step towards personalized treatment for cancer patients.

Availability and implementation

https://github.com/gevaertlab/MultimodalPrognosis
Large-scale mammalian genome rearrangements coincide with chromatin interactions
Authors: Swenson Krister M , Blanchette Mathieu
Published: May 2019

Motivation

Genome rearrangements drastically change gene order along great stretches of a chromosome. There has been initial evidence that these apparently non-local events in the 1D sense may have breakpoints that are close in the 3D sense. We harness the power of the Double Cut and Join model of genome rearrangement, along with Hi-C chromosome conformation capture data to test this hypothesis between human and mouse.

Results

We devise novel statistical tests that show that indeed, rearrangement scenarios that transform the human into the mouse gene order are enriched for pairs of breakpoints that have frequent chromosome interactions. This is observed for both intra-chromosomal breakpoint pairs, as well as for inter-chromosomal pairs. For intra-chromosomal rearrangements, the enrichment exists from close (<20 Mb) to very distant (100 Mb) pairs. Further, the pattern exists across multiple cell lines in Hi-C data produced by different laboratories and at different stages of the cell cycle. We show that similarities in the contact frequencies between these many experiments contribute to the enrichment. We conclude that either (i) rearrangements usually involve breakpoints that are spatially close or (ii) there is selection against rearrangements that act on spatially distant breakpoints.

Availability and implementation

Our pipeline is freely available at https://bitbucket.org/thekswenson/locality.

Supplementary information

Supplementary data are available at Bioinformatics online.