bluuebunny/crossref_metadata_2025 huggingface dataset:
Tricompartmental, Remote Intracerebral Hemorrhages Following Drainage of a Unilateral Chronic Subdural Hematoma: An Appraisal of the Pathogenesis
Authors: Krishnan Prasad , Ghosh Nabanita
Published: September 2020

Intracerebral hemorrhage is a rare and unanticipated complication after burr hole drainage of a chronic subdural hematoma and usually occurs on the same side as the hematoma. In the absence of bleeding diathesis, iatrogenic injury or hypertension, it is commonly attributed to sudden expansion of the compressed brain, following rapid and uncontrolled removal of the subdural hematoma. Other factors like differential expansion of the various intracranial contents, abrupt changes in hemispheric balance, precipitous increase in focal cerebral blood flow, and unforeseen increase in cerebral venous pressure consequent to faulty positioning may also contribute to the pathogenesis of this complication.
Cardiovascular Autonomic Dysfunction in Spinal Cord Injury: Epidemiology, Diagnosis, and Management
Authors: Wecht Jill M. , Harel Noam Y. , Guest James , Kirshblum Steven C. , Forrest Gail F. , Bloom Ona , Ovechkin Alexander V. , Harkema Susan
Published: September 2020

Spinal cord injury (SCI) disrupts autonomic circuits and impairs synchronistic functioning of the autonomic nervous system, leading to inadequate cardiovascular regulation. Individuals with SCI, particularly at or above the sixth thoracic vertebral level (T6), often have impaired regulation of sympathetic vasoconstriction of the peripheral vasculature and the splanchnic circulation, and diminished control of heart rate and cardiac output. In addition, impaired descending sympathetic control results in changes in circulating levels of plasma catecholamines, which can have a profound effect on cardiovascular function. Although individuals with lesions below T6 often have normal resting blood pressures, there is evidence of increases in resting heart rate and inadequate cardiovascular response to autonomic provocations such as the head-up tilt and cold face tests. This manuscript reviews the prevalence of cardiovascular disorders given the level, duration and severity of SCI, the clinical presentation, diagnostic workup, short- and long-term consequences, and empirical evidence supporting management strategies to treat cardiovascular dysfunction following a SCI.
Surgical Approaches to the Orbit: A Neurosurgical Perspective
Authors: Abussuud Zeid , Ahmed Shahzada , Paluzzi Alessandro
Published: September 2020

Orbital pathologies can be complex to manage surgically. In this article, we describe some of the most common and relevant approaches to orbital tumours. For each approach we describe the appropriate indications, surgical technique, potential complications, and illustrate a case example.
Hemostasis and Liver Regeneration
Authors: Starlinger Patrick , Luyendyk James P. , Groeneveld Dafna J.
Published: September 2020

The liver is unique in its remarkable regenerative capacity, which enables the use of liver resection as a treatment for specific liver diseases, including removal of neoplastic liver disease. After resection, the remaining liver tissue (i.e, liver remnant) regenerates to maintain normal hepatic function. In experimental settings as well as patients, removal of up to two-thirds of the liver mass stimulates a rapid and highly coordinated process resulting in the regeneration of the remaining liver. Mechanisms controlling the initiation and termination of regeneration continue to be discovered, and many of the fundamental signaling pathways controlling the proliferation of liver parenchymal cells (i.e., hepatocytes) have been uncovered. Interestingly, while hemostatic complications (i.e., bleeding and thrombosis) are primarily thought of as a complication of surgery itself, strong evidence suggests that components of the hemostatic system are, in fact, powerful drivers of liver regeneration. This review focuses on the clinical and translational evidence supporting a link between the hemostatic system and liver regeneration, and the mechanisms whereby the hemostatic system directs liver regeneration discovered using experimental settings.
Preoperative Emergency Department Visits Are Predictive of 90-Day Postoperative Emergency Department Visits and Discharge Disposition in Total Knee Arthroplasty Patients
Authors: Kiskaddon Eric M. , Soehnlen Neil T. , Erb Eric , Froehle Andrew W. , Green Uthona , Krishnamurthy Anil
Published: September 2020

The increasing number of patients undergoing total knee arthroplasty (TKA) has resulted in efforts to better understand patient utilization of healthcare services in the 90-day postoperative period. The primary purpose of this study was to examine whether emergency department (ED) visits in the year prior to elective TKA were predictive of postoperative ED visits in the 90-day global period following surgery. A retrospective chart review was performed for all patients undergoing TKA from June 1, 2011 to December 31, 2015 at a Veterans Affairs hospital. Total number of ED visits in the year prior to surgery and 90 days following surgery were tabulated. Binary and ordinal logistic regression analyses were utilized to determine if preoperative ED visits were predictive of postoperative ED visits. The significance level was set to α = 0.05. Overall, 611 eligible TKA procedures were performed. The logistic regression model for postoperative ED visits was significant (p < 0.001), with the number of preoperative ED visits (1 vs. 0: p < 0.001; 2 vs. 1: p = 0.012) and presence of diabetes (p = 0.007) both predicting the likelihood of a postoperative ED visit. Healthcare changes that are redefining the concept of quality of care to include the postoperative care episode, coupled with an increasingly aging population in need of TKA, will continue to challenge orthopaedic surgeons to provide safe, competent, and cost-effective care to patients. The results of this study demonstrate that a patient's propensity to visit the ED prior to TKA is predictive of a tendency to do so postoperatively and is of use to surgeons when evaluating and counselling patients who will be undergoing a TKA.
D2-Hydroxyglutaric Aciduria Type II with Subdural Hemorrhage Identified in a 3-Month-Old Infant: A Case Report
Authors: Green Jennie , Rao Vinod , Currie Melissa
Published: September 2020

Subdural hemorrhage in association with D2-hydroxyglutaric aciduria (D2-HGA) Type II has only been described once in the medical literature in a 15-month-old child (1). Our case report describes a much younger 3-month-old infant previously diagnosed with D2-HGA Type II, who presented clinically with seizures and identified to have bilateral subdural hematomas concerning for possible physical abuse. This case report discusses the genetic diagnosis of D2-HGA and interpretation of subdural hemorrhage in context of evaluating possible physical abuse concerns. When an underlying medical condition is known to be present and a child presents with findings that may be concerning for physical abuse, it is critical to consider the possibility that the underlying medical condition may contribute to or may be the cause of the findings.
Super-chiral vibrational spectroscopy with metasurfaces for high-sensitive identification of alanine enantiomers
Authors: Iida Takumi , Ishikawa Atsushi , Tanaka Takuo , Muranaka Atsuya , Uchiyama Masanobu , Hayashi Yasuhiko , Tsuruta Kenji
Published: September 2020

Chiral nature of an enantiomer can be characterized by circular dichroism (CD) spectroscopy, but such a technique usually suffers from weak signal even with a sophisticated optical instrument. Recent demonstrations of plasmonic metasurfaces showed that chiroptical interaction of molecules can be engineered, thereby greatly simplifying a measurement system with high sensing capability. Here, by exploiting super-chiral field in a metasurface, we experimentally demonstrate high-sensitive vibrational CD spectroscopy of alanine enantiomers, the smallest chiral amino acid. Under linearly polarized excitation, the metasurface consisting of an array of staggered Au nano-rods selectively produces the left- and right-handed super-chiral fields at 1600 cm−1, which spectrally overlaps with the functional group vibrations of alanine. In the Fourier-transform infrared spectrometer measurements, the mirror symmetric CD spectra of D- and L-alanine are clearly observed depending on the handedness of the metasurface, realizing the reliable identification of small chiral molecules. The corresponding numerical simulations reveal the underlying resonant chiroptical interaction of plasmonic modes of the metasurface and vibrational modes of alanine. Our approach demonstrates a high-sensitive vibrational CD spectroscopic technique, opening up a reliable chiral sensing platform for advanced infrared inspection technologies.
Extended plateaux in the vibrational and electron distribution functions of O2/O reacting plasmas in discharge and post-discharge conditions
Authors: Pietanza L. D. , Colonna G. , Capitelli M.
Published: September 2020

An accurate state to state model describing the plasma kinetics in reacting oxygen plasma has been built up giving particular attention to vibrational–translational O–O2 processes, as well as O–O2(v) dissociation and recombination, direct electron impact dissociation, and resonant electron–vibration (e–V) processes for O2. Moderate and low pressure situations are investigated for both discharge and post-discharge conditions. In both cases, an important role of three body recombination of O atoms and of multi-quantum e–V processes is observed, the latter being particularly important at low pressure. The interplay of the different processes forms an extended plateaux on the vibrational distribution function (vdf) of O2 in both discharge and post-discharge conditions. A comparison between our calculated vdf and the corresponding experimental and theoretical results of Annusova et al. shows a good qualitative agreement. Declining plateaux are also observed in the electron energy distribution function. In this case, superelastic electronic collisions involving high lying electronic states of the O atom form important maxima over the declining plateau.
The hot issue: TOR signalling network in plants
Authors: Zhao Ying , Wang Xiu-Qin
Published: September 2020

The target of rapamycin (TOR) signalling network plays a pivotal role in regulating sugar metabolism and life-span in yeast, plants and mammals, in which TOR functions as a crucial protein. In plants, the TOR complex comprises TOR, RAPTOR (regulatory-associated protein of TOR) and LST8 (lethal with SEC13 protein 8). Factors like light, auxin, glucose, sucrose and amino acid can activate TOR protein as upstream signals to further phosphorylate downstream factors of TOR which promote cell proliferation and growth in plants. In this review, we analyse the TOR signalling network in plants and discuss the relationship between glucose and TOR, as well as the dynamic balance between TOR and sucrose-non-fermenting-related protein kinases (SnRKs). Given that 63 novel TOR-regulated proteins have been identified in previous studies, we also believe there are many unknown functions of TOR that need to be further investigated.
Clathrin light chain diversity regulates membrane deformation in vitro and synaptic vesicle formation in vivo
Authors: Redlingshöfer Lisa , McLeod Faye , Chen Yu , Camus Marine D. , Burden Jemima J. , Palomer Ernest , Briant Kit , Dannhauser Philip N. , Salinas Patricia C. , Brodsky Frances M.
Published: September 2020

Significance

This study reveals that diversity of clathrin light chain (CLC) subunits alters clathrin properties and demonstrates that the two neuronal CLC subunits work together for optimal clathrin function in synaptic vesicle formation. Our findings establish a role for CLC diversity in synaptic transmission and illustrate how CLC variability expands the complexity of clathrin to serve tissue-specific functions.
Human norovirus exhibits strain-specific sensitivity to host interferon pathways in human intestinal enteroids
Authors: Lin Shih-Ching , Qu Lin , Ettayebi Khalil , Crawford Sue E. , Blutt Sarah E. , Robertson Matthew J. , Zeng Xi-Lei , Tenge Victoria R. , Ayyar B. Vijayalakshmi , Karandikar Umesh C. , Yu Xiaomin , Coarfa Cristian , Atmar Robert L. , Ramani Sasirekha , Estes Mary K.
Published: September 2020

Significance

Host innate immune responses are the first line of defense against viral infections, with the outcome of infection determined by the interplay between virus and host defense mechanisms. We report transcriptomic and functional analyses of epithelial cell responses to HuNoV infection in HIE cultures. HuNoV infection triggers predominantly a type III interferon (IFN) response and upregulation of long noncoding RNAs. Exogenously added IFNs restrict HuNoV replication in a strain-independent manner, but we unexpectedly found strain-dependent effects of endogenously activated cellular IFNs. Our findings suggest strain-specific sensitivities to IFN as a factor for global dominance of pandemic strains, provide a new arsenal of stable HIE knockout lines for several IFN pathways, and highlight strain differences as a consideration for development of effective therapies.
Chemical nonequilibrium modelling of a free-burning nitrogen arc
Authors: Wang Hai-Xing , Zhu Tao , Sun Su-Rong , Liu Gang , Murphy Anthony B
Published: September 2020

Thermal and chemical nonequilibrium modelling is performed to investigate the plasma characteristics of a nitrogen arc. The arc plasma is coupled with the electrodes self-consistently in the computational domain. The self-consistent effective binary diffusion coefficient approximation treatment of diffusion and a generalized form of Ohm’s law are incorporated in the model. It is found the electric field has to undergo a reversal in front of the anode to preserve current conservation due to the strong diffusion current density. No field reversal is found in front of the cathode. The detailed chemical reaction processes are analyzed to understand the species density behaviour. Along the cathode surface, the maximum values of current density and heat flux density occur at the intersection of the flat tip and the conical surface. The distributions of different components of the current density and heat flux density change with the arc current. On the anode side, the electric field and diffusion components contribute to the current density, and have opposite signs and similar magnitudes on the axis, leading to an off-axis maximum of the current density. The electron condensation heat makes the largest contribution to the total heat flux in the high current density region, and the heavy-species contribution from the plasma becomes important in the arc fringe. The high heat flux and current density at the anode show that the nitrogen arc possesses excellent energy source properties for arc welding and other processes that require workpiece melting.
Non-relaxor behaviour of low-frequency vibration spectra of relaxor ferroelectric PbCo1/3Nb2/3O3: evidences from Brillouin and Raman scattering measurements
Authors: Lee J W , Ko J-H , Fedoseev A I , Smirnova T A , Lushnikov S G
Published: September 2020

This paper presents the results of studies of a low-frequency vibration spectrum of PbCo1/3Nb2/3O3 (PCN) relaxor ferroelectric crystal using the Brillouin and Raman light scattering in the temperature range from 80 to 750 K. The analysis of the temperature behaviour of the longitudinal acoustic phonon in Brillouin scattering spectra showed no anomalies in the vicinity of ‘diffuse phase transition’ (T
m = 250 K) in PCN. Polarized Raman light scattering spectra were obtained in PCN over the entire temperature range studied. Analysis of low-frequency optical mode behaviour in PCN during temperature change also revealed no correlations with dielectric permeability anomaly in the vicinity of T
m: softening of optical phonon at 43 cm−1 frequency in VV polarization is observed at 170 K. In the same temperature range, there are anomalies (a ‘narrow’ and weak component) in quasi-elastic light scattering (QELS) obtained in temperature behaviour with VH polarization in Raman spectra in PCN. A ‘wide’ and intense QELS component, obtained in Raman spectra with VV polarization, shows anomalies in the vicinity of T
m. We associate the anomalies of optical phonons and QELS with structure distortions in the formation of phase stratification and the dynamics of polar nano-regions.
The observed topological vortex domains and the rotating magnetocaloric effect in the hexagonal RMnO3 (R = Ho, Er, and Yb) crystals
Authors: Wang Wei , Li Ye , Li Leiyu , Li Qianjie , Wang Dongdong , Zhu Jiangyuan , Li Jin , Zeng Min
Published: September 2020

Hexagonal RMnO3 (R = Er, Ho and Yb) single crystals were grown and their unique vortex domain structures, magnetic properties and magnetocaloric effect (MCE) were comprehensively investigated. The topological vortex domains/structures were clearly illustrated by polarized optical microscope and piezo response force microscopy, confirming a high quality of the crystals. The magnetic transitions related to R
3+–Mn3+ interactions and anisotropic properties were observed in the RMnO3 crystals. The broad peaks of magnetic entropy change −ΔS
M appeared around

T

N

R

revealed that the order of R
3+ moments is crucial to the large MCE. A giant rotating MCE (RMCE: ∼10.57 J kg−1 K−1) was obtained with magnetic field changing from 0 to 50 kOe in ErMnO3, accompanied with a large refrigerant capacity (RC: ∼159 J kg−1). These significant RMCE and RC behaviors are found to be closely related to the R
3+–R
3+, and R
3+–Mn3+ interactions in these RMnO3. These results may open up a possibility for designing low-temperature magnetic cooling devices by tailoring the R–4f and Mn–3d orbit interactions.
Molten salt synthesis of carbon-doped boron nitride nanosheets with enhanced adsorption performance
Authors: Wang Honghong , Tian Liang , Huang Zhong , Liang Feng , Guan Keke , Jia Quanli , Zhang Haijun , Zhang Shaowei
Published: September 2020

Owing to their large specific areas, high thermal stability and chemical inertness, two-dimensional boron carbon nitride nanosheets (BCNNs) have captured much attention in recent years in the field of adsorption of pollutants. The formation of BCNNs via incorporating carbon into boron nitride (BN) can effectively improve the photoelectric and adsorption properties of the latter. In this work, carbon-doped BN (BCN) nanosheets were prepared at 1100 °C via a molten salt route using boric acid, melamine and glucose as the main starting materials. The effects of molten salt type and carbon doping level on the formation of BCN were investigated, and their isothermal adsorption properties in a methylene blue (MB) aqueous solution were evaluated based on the Langmuir and Freundlich models. The results indicated that using molten LiCl-KCl as a liquid medium was more favorable than NaCl-KCl to the formation of BCNNs. As-prepared BC0.4N sample possessed a sheet-like structure of about 10 nm thick and a specific surface area as high as 484 m2 g−1. Moreover, the adsorption test of MB demonstrated a high adsorption capacity of 249.04 mg g−1, which was about 14 times higher than that in the case of the pristine BN, and the kinetic rate constant value in the case of using BC0.4N is about ten times as high as that of BN following a pseudo-second-order model, suggesting that the as-formed BC0.4N nanosheets could be potentially used as a value-added effective adsorbent for future wastewater remediation.
Growth of zinc-blende GaN on muscovite mica by molecular beam epitaxy
Authors: Daudin Bruno , Donatini Fabrice , Bougerol Catherine , Gayral Bruno , Bellet-Amalric Edith , Vermeersch Rémy , Feldberg Nathaniel , Rouvière Jean-Luc , Recio Carretero Maria José , Garro Núria , Garcia-Orrit Saül , Cros Ana
Published: September 2020

The mechanisms of plasma-assisted molecular beam epitaxial growth of GaN on muscovite mica were investigated. Using a battery of techniques, including scanning and transmission electron microscopy, atomic force microscopy, cathodoluminescence, Raman spectroscopy and x-ray diffraction, it was possible to establish that, in spite of the lattice symmetry mismatch, GaN grows in epitaxial relationship with mica, with the [11–20] GaN direction parallel to [010] direction of mica. GaN layers could be easily detached from the substrate via the delamination of the upper layers of the mica itself, discarding the hypothesis of a van der Waals growth mode. Mixture of wurtzite (hexagonal) and zinc blende (ZB) (cubic) crystallographic phases was found in the GaN layers with ratios highly dependent on the growth conditions. Interestingly, almost pure ZB GaN epitaxial layers could be obtained at high growth temperature, suggesting the existence of a specific GaN nucleation mechanism on mica and opening a new way to the growth of the thermodynamically less stable ZB GaN phase.
Novel adjustable monolayer carbon nitride membranes for high-performance saline water desalination
Authors: Mehrdad Mohammad , Moosavi Ali
Published: September 2020

In this study, via molecular dynamic simulations, we showed that the latest described graphene-like carbon nitride membranes, such as g-C4N3, g-C6N6, and g-C3N4 single-layers, can be used as high-performance membranes for water desalination. In addition to having inherent nanopores and extraordinary mechanical properties, the carbon nitride membranes have high water permeability and strong ion rejection (IR) capability. The important point about carbon nitride membranes is that the open or closed state of the pores can be changed by applying tensile stress and creating a positive strain on the membrane. The effect of the imposed pressure, the tensile strain, the ion concentration, and the effective pore size of the membranes are reported. It is demonstrated that, with the applied tensile strain of 12%, the g-C6N6 membrane is the best purification membrane, with a water permeability of 54.16 l cm−2 d−1 MPa−1 and the IR of 100%. Its water permeability is one order of magnitude greater than other one-atom-thick membranes.
MXene-based ultra-thin film for terahertz radiation shielding
Authors: Zou Qi , Guo Wenyu , Zhang Long , Yang Liting , Zhao Zhenyu , Liu Feng , Ye Xiang , Zhang Yi , Shi Wangzhou
Published: September 2020

We have successfully fabricated Ti-based MXenes flakes, Ti3C2Tx, by chemical etching, then prepared it as an organic dispersion and finally spin-coated it on polyimide plastic substrate for terahertz wave shielding. The shielding effectivity of the 12 μm ultra-thin film can reach up to 17 dB measured by the terahertz time-domain spectra. We can attribute the excellent phenomenon to the intrinsic absorption of triple-layered Ti3C2, due to the similar double-peak type refraction curves, which have been respectively observed from the experimental samples and the simulation ones. High conductivity and strong THz absorption indicate the Ti3C2Tx MXene is the absorptive electromagnetic shielding material. Comparing with other kinds of THz shielding materials, the Ti-based MXenes might be a potential candidate for the next generation of ultra-thin and lightweight THz shielding.
Impact of scanner harmonization on PET-based treatment response assessment in metastatic melanoma
Authors: Weisman Amy J , Bradshaw Tyler J , Namias Mauro , Jeraj Robert
Published: September 2020

Patients with metastatic melanoma often receive 18F-FDG PET/CT scans on different scanners throughout their monitoring period. In this study, we quantified the impact of scanner harmonization on longitudinal changes in PET standardized uptake values using various harmonization and normalization methods, including an anthropomorphic PET phantom. Twenty metastatic melanoma patients received at least two FDG PET/CT scans, each on two different scanners with an average of 4 months (range: 2–8) between. Scans from a General Electric (GE) Discovery 710 PET CT−1 were harmonized to the GE Discovery VCT using image reconstruction settings matching recovery coefficients in an anthropomorphic phantom with bone equivalent inserts and wall-less synthetic lesions. In patient images, SUVmax was measured for each melanoma lesion and time-point. Lesions were classified as progressing, stable, or responding based on pre-defined threshold of ±30% change in SUVmax. For comparison, harmonization was also performed using simpler methods, including harmonization using a NEMA phantom, post-reconstruction filtering, reference region normalization of SUVmax, and use of SUVpeak instead of SUVmax. In the 20 patients, 90 lesions across two time-points were available for treatment response assessment. Treatment response classification changed in 47% (42/90) of cases after harmonization with anthropomorphic phantom. Before harmonization, 37% (33/90) of the lesions were classified as stable (changing less than 30% between two time-points), while the fraction of stable lesions increased to 58% (52/90) after harmonization. Harmonization with the NEMA phantom agreed with harmonization with the anthropomorphic phantom in 91% (82/90) of cases. Post-reconstruction filtering agreed with anthropomorphic phantom-based harmonization in 83% (75/90) cases. The utilization of reference regions for normalization or SUVpeak was unable to correct for changes as identified by the anthropomorphic phantom-based harmonization. Overall, PET scanner harmonization has a major impact on individual lesion treatment response classification in metastatic melanoma patients. Harmonization using the NEMA phantom yielded similar results to harmonization using anthropomorphic phantom, while the only acceptable post-reconstruction technique was post-reconstruction filtering. Phantom-based harmonization is therefore strongly recommended when comparing lesion uptake across time-points when the images have been acquired on different PET scanners.
Comparison of 11 automated PET segmentation methods in lymphoma
Authors: Weisman Amy J , Kieler Minnie W , Perlman Scott , Hutchings Martin , Jeraj Robert , Kostakoglu Lale , Bradshaw Tyler J
Published: September 2020

Segmentation of lymphoma lesions in FDG PET/CT images is critical in both assessing individual lesions and quantifying patient disease burden. Simple thresholding methods remain common despite the large heterogeneity in lymphoma lesion location, size, and contrast. Here, we assess 11 automated PET segmentation methods for their use in two scenarios: individual lesion segmentation and patient-level disease quantification in lymphoma. Lesions on 18F-FDG PET/CT scans of 90 lymphoma patients were contoured by a nuclear medicine physician. Thresholding, active contours, clustering, adaptive region-growing, and convolutional neural network (CNN) methods were implemented on all physician-identified lesions. Lesion-level segmentation was evaluated using multiple segmentation performance metrics (Dice, Hausdorff Distance). Patient-level quantification of total disease burden (SUVtotal) and metabolic tumor volume (MTV) was assessed using Spearman’s correlation coefficients between the segmentation output and physician contours. Lesion segmentation and patient quantification performance was compared to inter-physician agreement in a subset of 20 patients segmented by a second nuclear medicine physician. In total, 1223 lesions with median tumor-to-background ratio of 4.0 and volume of 1.8 cm3, were evaluated. When assessed for lesion segmentation, a 3D CNN, DeepMedic, achieved the highest performance across all evaluation metrics. DeepMedic, clustering methods, and an iterative threshold method had lesion-level segmentation performance comparable to the degree of inter-physician agreement. For patient-level SUVtotal and MTV quantification, all methods except 40% and 50% SUVmax and adaptive region-growing achieved a performance that was similar the agreement of the two physicians. Multiple methods, including a 3D CNN, clustering, and an iterative threshold method, achieved both good lesion-level segmentation and patient-level quantification performance in a population of 90 lymphoma patients. These methods are thus recommended over thresholding methods such as 40% and 50% SUVmax, which were consistently found to be significantly outside the limits defined by inter-physician agreement.
Pancreas segmentation based on an adversarial model under two-tier constraints
Authors: Li Meiyu , Lian Fenghui , Guo Shuxu
Published: September 2020

Pancreas segmentation is vital for the effective diagnosis and treatment of diabetic or pancreatic diseases. However, the irregular shape and strong variability of the pancreas in medical images pose significant challenges to accurate segmentation. In this paper, we propose a novel segmentation algorithm that imposes two-tier constraints on a conventional network through adversarial learning, namely UDCGAN. Specifically, we incorporate a dual adversarial training scheme in a conventional segmentation network, which further facilitates the probability maps from the segmentor to converge on the ground truth distributions owing to the effectiveness of generative adversarial networks (GANs) in capturing data distributions. This novel segmentation algorithm is equivalent to employing adversarial learning on a segmentation network that has been trained in an adversarial manner. Duplex intervention and guidance further refine the loss functions of the segmentor, thus effectively contributing to the preservation of details for segmentation. The segmentation results on the NIH Pancreas-CT dataset show that our proposed model achieves a competitive performance compared with other state-of-the-art methods.
Study on generation characteristics of plasma jets of multi-electrode in a pulse vacuum discharge
Authors: Liu Wenzheng , Zhang Wenjun , Tian Jia , Gao Yongjie , Zhao Luxiang
Published: September 2020

In order to increase the production of plasma jets in a pulse vacuum discharge, based on the insulated anode electrode structure (IAES), discharge experiments by using multiple electrodes under one power supply are performed in this paper. During experiments, discharge currents flowing through multiple cathode sides (cathode currents) were measured by identical Rogowski coils at the same time. The plasma density and propagation velocity of plasma jets were measured by the self-designed ‘+’ type probes. Firstly, the differences in discharge characteristics and generation characteristics of plasma jets between the single-electrode and the double-electrode discharge were compared and analyzed. Secondly, the effects that the electrode spacing (D) and the capacitor capacity had on the discharge characteristics and generation characteristics of plasma jets of the multi-electrode were analyzed. Results show that because the discharge voltage of the IAES is dropped to the arc voltage after a long duration, the simultaneous discharge of multiple electrodes in a single pulse can be realized. Compared with the single-electrode discharge, using multiple electrodes to discharge simultaneously in a single pulse can decrease the initial discharge voltage, increase the peak of cathode current and increase the amount of plasma production. In addition, there is interaction between plasma jets of the multi-electrode, and the spatial electric field generated by the first ejected plasma jet will hinder the generation of plasma jets of subsequent electrodes. Only by keeping a certain electrode spacing (D) between the electrodes, can multiple electrodes be all discharged and plasma jets of the same length be produced. Increasing capacitor capacity can increase the plasma density, propagation velocity, length of plasma jets of the multi-electrode, and realize the simultaneous discharge of more electrodes in a single pulse.
Macroscopic quantumness of optically conditioned mechanical systems
Authors: McAleese Hannah , Paternostro Mauro
Published: September 2020

We address the macroscopic quantumness of the state of mechanical systems subjected to conditional protocols devised for state engineering in cavity optomechanics. We use a measure of macroscopicity based on phase-space methods. We cover the transition regime into strong single-photon coupling, illustrating how measurements performed over the cavity field that drives the dynamics of a mechanical system are able to steer the latter toward large quantum coherent states. The effect of losses is evaluated for the case of an open cavity and analyzed in terms of the features of the Wigner functions of the state of the mechanical system. We also address the case of engineered phonon-subtracted mechanical systems, in full open-system configuration, demonstrating the existence of optimal working points for the sake of mesoscopic quantumness. Our study is relevant for and applicable to a broad range of settings, from clamped to levitated mechanical systems.
Unsteady MHD squeezing flow of Jeffrey fluid in a porous medium with thermal radiation, heat generation/absorption and chemical reaction
Authors: Mat Noor Nur Azlina , Shafie Sharidan , Admon Mohd Ariff
Published: September 2020

The numerical study is presented for the magnetohydrodynamic (MHD) squeezing flow of Jeffrey fluid between two parallel plates in a porous medium with the presence of thermal radiation, heat generation/absorption and chemical reaction. The effect of joule heating and viscous dissipation are also examined. Similarity transformation is implemented to transform the governing nonlinear partial differential equations into the system of ordinary differential equations. The resulting equations are solved via numerical scheme of Keller-box method. The accuracy of the present results is validated by comparing the skin friction coefficient, Nusselt and Sherwood numbers with previous published works. The results are noticed in good agreement. Findings reveal that fluid velocity and wall shear stress accelerate when the plate is squeezed. Also, the fluid velocity, temperature and concentration reduce with increase in ratio of relaxation to retardation times and Hartmann number. The increment of viscous dissipation and heat source/sink boost the fluid temperature and the rate of heat transfer. Meanwhile, the presence of thermal radiation decreases the fluid temperature and increases the rate of heat transfer. Further, the rate of mass transfer elevates in the destructive chemical reaction and reverse effect is shown in the convective chemical reaction.
Fluorinating the graphene-like BeO monolayer: A spin-polarized first principles study of the electronic, magnetic and optical properties
Authors: Van On Vo , Hoat D M , Nguyen Duy Khanh , Ponce-Pérez R , Vu Tuan V , Rivas-Silva J F , Cocoletzi Gregorio H
Published: September 2020

Chemical functionalization of low-dimensional materials has been widely employed to create new multifunctional materials with novel properties. In this paper, we present the results of the fluorination effects on the structural, electronic, magnetic, and optical properties of the BeO monolayer. Materials stability is examined by means of the phonon dispersion curves and binding energy. Significant structural changes of the BeO monolayer are induced by the fluorination. The pristine single layer possesses a wide indirect K − Γ band gap of 5.23 eV with no spin-polarization. Either half-metallic or magnetic semiconductor structures with important ferromagnetism can be induced by the half-fluorination, and a total magnetic moment of 1 μ

B
may be obtained. The full-fluorination produces a magnetism-free material, however causes the indirect-direct gap transition and a considerable reduction of the energy gap to 0.97 eV. The fluorination enhances the BeO monolayer optical properties in the low energy regime, and also the interaction with the light polarized in the z-direction. Our simulations suggest that the fluorination may be an effective approach to tune the BeO single layer physical properties producing new materials, which are expected to find prospective applications in the spintronic and optoelectronic nano-devices.
Review of multimer protein–protein interaction complex topology and structure prediction*
Authors: Sun Daiwen , Liu Shijie , Gong Xinqi
Published: September 2020

Protein–protein interactions (PPI) are important for many biological processes. Theoretical understanding of the structurally determining factors of interaction sites will help to understand the underlying mechanism of protein–protein interactions. At the same time, understanding the complex structure of proteins helps to explore their function. And accurately predicting protein complexes from PPI networks helps us understand the relationship between proteins. In the past few decades, scholars have proposed many methods for predicting protein interactions and protein complex structures. In this review, we first briefly introduce the methods and servers for predicting protein interaction sites and interface residue pairs, and then introduce the protein complex structure prediction methods including template-based prediction and template-free prediction. Subsequently, this paper introduces the methods of predicting protein complexes from the PPI network and the method of predicting missing links in the PPI network. Finally, it briefly summarizes the application of machine/deep learning models in protein structure prediction and action site prediction.
Plasmonic characteristics of suspended graphene-coated wedge porous silicon nanowires with Ag partition*
Authors: Wang Xu , Wang Jue , Ma Tao , Liu Heng , Wang Fang
Published: September 2020

We investigate a graphene-coated nanowire waveguide (GCNW) composed of two suspended wedge porous silicon nanowires and a thin Ag partition. The plasmonic characteristics of the proposed structure in terahertz (THz) frequency band are simulated by the finite element method (FEM). The parameters including the gap between the nanowires and Ag partition, the height of the nanowire, the thickness of the Ag partition, and the Fermi level of graphene, are optimized. The simulation results show that a normalized mode field area of ∼ 10−4 and a figure of merit of ∼ 100 can be achieved. Compared with the cylindrical GCNW and isolated GCNW, the proposed wedge GCNW has good electric field enhancement. A waveguide sensitivity of 32.28 is obtained, which indicates the prospects of application in refractive index (RI) sensing in THz frequency band. Due to the adjustable plasmonic characteristics by changing the Fermi level (E
F), the proposed structure has promising applications in the electro-optic modulations, optical interconnects, and optical switches.
Optical conductivity of twisted bilayer graphene near the magic angle*
Authors: Wen Lu , Li Zhiqiang , He Yan
Published: September 2020

We theoretically study the band structure and optical conductivity of twisted bilayer graphene (TBG) near the magic angle considering the effects of lattice relaxation. We show that the optical conductivity spectrum is characterized by a series of peaks associated with the van Hove singularities in the band structure, and the peak energies evolve systematically with the twist angle. Lattice relaxation effects in TBG modify its band structure, especially the flat bands, which leads to significant shifts of the peaks in the optical conductivity. These results demonstrate that spectroscopic features in the optical conductivity can serve as fingerprints for exploring the band structure, band gap, and lattice relaxation in magic-angle TBG as well as identifying its rotation angle.
Decoherence of fiber light sources using a single-trench fiber*
Authors: Zhang Huahui , Zhang Weili , Wang Zhao , Zhu Hongyang , Yu Chao , Guo Jiayu , Wang Shanshan , Rao Yunjiang
Published: September 2020

Decoherence of fiber laser sources is of great importance in imaging applications, and most current studies use ordinary multi-mode fibers (MMFs). Here, a newly designed single-trench fiber (STF) is investigated to reduce the spatial coherence of fiber light source and compared with MMFs. By bending two fibers with different turns, speckle contrast of a 0.8-m-long STF can be reduced from 0.13 to 0.08, while a 0.8-m-long MMF shows an inverse result. Through speckle contrast and decoupling-mode analysis, the reason of this inverse trend is revealed. Firstly, the STF supports more modes than the MMF due to its larger core diameter. Secondly, mode leak from the first core of the STF can couple to the second core when bending the STF. Thus, power distribution among high and low-order modes become more even, reducing the spatial coherence considerably. However, in the MMF, high-order modes become leaky modes and decrease slightly when bending the fiber. This work provides a new method to modulate coherence of light source and a new angle to study decoherence principle using special fibers.
Variable optical chirality in atomic assisted microcavity*
Authors: Zhang Hao , Li Wen-Xiu , Han Peng , Chang Xiao-Yang , Jiang Shuo , Huang An-Ping , Xiao Zhi-Song
Published: September 2020

The manipulating of optical waves in a microcavity is essential to developing the integrated optical devices. Generally, the two eigenmodes in a whispering-gallery-mode (WGM) microcavity possess chiral symmetry. Here we show the chiral symmetry breaking is induced by the asymmetric backscattering of counter-propagating optical waves in a whispering-gallery-mode (WGM) microcavity with a cavity-made slot filled with atomic vapor. Through tuning the dispersion relation of the atomic vapor in the cavity-made slot, the chiral modes are continuously steered. The mode frequency splitting in the transmission and reflection spectra stem from the chiral symmetry breaking of the two eigenmodes. The displacement sensitivity of the proposed system in response to the length variation of cavity-made slot exhibits a high sensitivity value of 15.22 THz/nm.
Broadband asymmetric transmission for linearly and circularly polarization based on sand-clock structured metamaterial*
Authors: Fu Tao , Liu Xing-Xing , Wen Guo-Hua , Sun Tang-You , Xiao Gong-Li , Li Hai-Ou
Published: September 2020

We proposed a sandwich structure to realize broadband asymmetric transmission (AT) for both linearly and circularly polarized waves in the near infrared spectral region. The structure composes of a silica substrate and two sand-clock-like gold layers on the opposite sides of the substrate. Due to the surface plasmons of gold, the structure shows that the AT parameters of linearly and circularly polarized waves can reach 0.436 and 0.403, respectively. Meanwhile, a broadband property is presented for the AT parameter is over 0.3 between 320 THz and 340 THz. The structure realizes a diode-like AT for linearly wave in forward and circularly wave in backward, respectively. The magnetic dipoles excited by current in the two gold layers contribute to the broadband AT. The current density in top and bottom metallic layers illustrates the mechanism of the polarization conversion for broadband AT in detail.
Structure prediction, electronic, and mechanical properties of alkali metal MB12 (M = Be, Mg, Ca, Sr) from first principles*
Authors: Pu Chun-Ying , Yu Rong-Mei , Wang Ting , Xüe Zhen-Yan , Zhu Yong-Sheng , Zhou Da-Wei
Published: September 2020

Using the particle swarm optimization algorithm on structural search methods, we focus our crystal structures search on boron-rich alkali metal compounds of MB12 (M = Be, Mg, Ca, Sr) with simulation cell sizes of 1–2 formula units (f.u.) at 0 GPa. The structure, electronic, and mechanical properties of MB12 are obtained from the density functional theory using the plane-wave pseudopotential method within the generalized gradient approximations. The formation enthalpies of MB12 regarding to solid metal M and solid alpha-boron suggested the predicted structures can be synthesized except for BeB12. The calculated band structures show MB12 (M = Be, Mg, Ca, Sr) are all indirect semiconductors. All the calculated elastic constants of MB12 satisfy the the mechanical stable conditions. The mechanical parameters (i.e., bulk modulus, shear modulus, and Young’s modulus) are derived using the Voigt–Reuss–Hill method. The G/B ratios indicated that the MB12 should exhibit brittle behavior. In addition, the hardness, Debye temperature, universal anisotropic index, and the percentage of anisotropy in compression and shear are also discussed in detail. We hope our results can inspire further experimental study on these boron-rich alkali-metal compounds.
Dynamic crossover in [VIO2+][Tf2N−]2 ionic liquid*
Authors: Ren Gan
Published: September 2020

Ionic liquids usually behave as fragile liquids, and the temperature dependence of their dynamic properties obeys supper-Arrhenius law. In this work, a dynamic crossover is observed in ([VIO2+][Tf2N−]2) ionic liquid at the temperature of 240–800 K. The diffusion coefficient does not obey a single Arrhenius law or a Vogel–Fulcher–Tammann (VFT) relation, but can be well fitted by three Arrhenius laws or a combination of a VFT relation and an Arrhenius law. The origin of the dynamic crossover is analyzed from correlation, structure, and thermodynamics. Ion gets a stronger backward correlation at a lower temperature, as shown by the fractal dimension of the random walk. The temperature dependence function of fractal dimension, heterogeneity order parameter, and thermodynamic data can be separated into three regions similar to that observed in the diffusion coefficient. The two crossover temperatures observed in the three types of data are almost the same as that in diffusion coefficient fitted by three Arrhenius laws. The results indicate that the dynamic crossover of [VIO2+][Tf2N−]2 is attributed to the heterogeneous structure when it undergoes cooling.
Electronic shell study of prolate Li
n
(n = 15–17) clusters: Magnetic superatomic molecules*
Authors: Yan Lijuan , Shao Jianmei , Li Yongqiang
Published: September 2020

The non-spherical lowest-lying Li
n
(n = 15–17) isomers were found with high symmetric compact structures, of which the stability was not rationalized in a previous report (J. Chem. Phys.
119 9444 (2003)). Based on the newly proposed super-valence bond model, the three prolate lithium clusters can be viewed as magnetic superatomic molecules, which are composed by sharing valence electron pairs and nuclei between two superatom units, namely, Li10 or Li11, and thus their stability can be given a good understanding. Molecular orbital and chemical bonding analysis clearly reveal that the Li
n
(n = 15–17) clusters with prolate shapes are magnetic superatomic molecules. Our work may aid in the developments of the cluster-assembled materials or superatom-bonds.
Identifying Pre-ictal Period of Seizure and Better Brain Lobes for Seizure Detection using EEG Biomarkers
Authors: Adalarasu K. , Shrisowmya P. , Jagannath M.
Published: September 2020

Seizures are one of the serious neuropsychiatric disorders that affect 50 million people across the world, and 80% of them live in the developing countries like India. In such kind of critical care, delays in the diagnosis of neurological conditions can have a significant impact on patients with seizure. To address this treatment gap, we propose an early identificationof pre-ictal period of seizure and brain lobes for seizure detection by using electroencephalogram (EEG) biomarkers. Five subjects were voluntarily involved in this study. The raw EEG signals were filtered and decomposed using wavelet techniques and the features such as relative delta energy, relative theta energy, total beta energy, heart rate, and neuronal activity were extracted for analysis. The results showed that the relative theta activity and the neuronal activity are found to be the better features in early predicting of period of pre-ictal seizures, as both the features can be seen with significant differences among the three different time periods in all the electrode positions, which are taken into consideration. It is also evident that the occipital lobe is better in indicating the pre-ictal period earlier, as the observed data shows expected outcome from the electrode positions O1 and O2 (occipital lobe). On national level, this study will enable the primary health centres to fulfil its dream of providing basic medical facilities to serve huge sections of population with seizure.