bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kirigami auxetic structure for high efficiency power harvesting in self-powered and wireless structural health monitoring systems
Authors: Farhangdoust Saman , Georgeson Gary , Ihn Jeong-Beom , Chang Fu-Kuo 
Published: November 2020

Abstract
Kirigami and auxetic topologies are combined to design an innovative metamaterial-based substrate (MetaSub) for piezoelectric energy harvesters. The proposed MetaSub piezoelectric energy harvester (MPEH) contains both advantageous metamaterial properties of negative Poisson’s ratio capability and enhanced planar stretchability. A computational parametric analysis is conducted to develop the optimum design for the MPEH to trap the maximum elastic energy. A finite element analysis (FEA) is employed to analytically and numerically validate the simulation model of the MPEH. Accordingly, two experimental results of conventional and auxetic strain energy harvesters are used to evaluate the power enhancement of the MPEH. The FEA results demonstrate the average power gained by the MPEH at a low level of frequency and strain excitation (10 Hz and 150

μ
ε

peak-to-peak) is 165

μ

W which easily satisfies the minimum electric power amount required as a sensor node for self-powered wireless sensor networks. The harvested power output of the MPEH is 19.2 times more than power output produced by an equivalent conventional harvester with a plain substrate (8.6

μ

W). The performance of the MPEH is investigated at different combinations of both low and high excitation frequencies. The creative design of the MetaSub can significantly improve the productivity of strain-induced devices whose efficiency is dependent on their deformation performance such as vibration energy harvesters, wearable sensors, flexible actuators, and micro electromechanical applications.
Surface acoustic wave pressure sensor on ScAlN/3C-SiC/Si layer structure incorporating biomimetic microcantilever: modelling and performance enhancement
Authors: Zhang Qiaozhen , Zhao Xiangyong , Wang Feifei , Luo Yang , Mao Hongwei , Han Tao 
Published: November 2020

Abstract
This paper presents a bio-inspired cantilever-type SAW pressure sensor based on Scandium-doped AlN (ScAlN)/3CSiC/Si layer structure. The proposed biomimetic microcantilever is configured with stress concentration region (SCR) comprising of a series of narrow slits. For a given depth, by properly setting the number and the width of those slits for a given depth, homogeneous stress/strain distribution in vicinity of SCR are achieved. Furthermore, multi-physics finite element modeling for evaluating the pressure coefficient of frequency (PCF) of a one-port SAW resonant sensor is performed and validated. Then the PCF for the proposed SAW pressure sensor with the optimized biomimetic microcantilever is analyzed. The dependence of ScAlN thin film thickness h
ScAlN and scandium-doped concentration r of Sc
r
Al1-r
N thin film on PCF for different SAW modes including Rayleigh mode and Sezawa mode are calculated. The investigation results show that the maximum PCF of −111 ppm bar−1 can be achieved for Rayleigh mode, which is 2.4 times larger than that of the previously reported ZnO/Si structure. In addition, its PCF has weak dependence on h
ScAlN, which are quite favorable for manufacturing pressure sensors with good reproducibility. The conceived bio-inspired cantilever-type SAW devices based on ScAlN/3 CSiC/Si structure will open the door to develop pressure sensors with a stable and reliable performance and enhanced sensitivity.
A proposal for a lightweight, large current superconducting cable for aviation
Authors: Yamaguchi Sataro , Kanda Masae 
Published: November 2020

Abstract
More Electric Aircraft (MEA) is one of the most important subjects for designing the next generation of aircraft. Since we cannot ground the electric power systems of a flying aircraft and the air insulation voltage is lower at high altitude, a low voltage, direct current (DC) aircraft electrical system is preferable for a MEA. Since the current must be high to supply high power, we consider high temperature superconducting (HTS) technology because it handles large currents well. We propose a new HTS cable in this paper. The cable uses a stacked conductor, with oppositely directed current in each HTS tape, a structure that has already been shown to be feasible for low voltage cables. It enhances the critical current compared to a single tape conductor, especially for Bi2223 tape. In order to avoid a current imbalance in the stacked conductor, we use the current lead resistance rather than a Roebel conductor design. Then the critical current remains high, and this is confirmed by measurements. The cryogenic pipe will be made of magnesium-lithium alloy, one of the lightest metals available at the present time. We estimate the weight-to-current ratio per unit length to be less than 0.5 kg/A/km at the liquid nitrogen operational temperature of 77 K, lighter than conventional copper cable. If instead we use liquid hydrogen at 20 K, we expect a value less than 0.1 kg/A/km, which is one of the lowest presently achievable values and satisfies the requirements for MEA.
Quantum chaos approach in exciton energy transfer in a photosynthetic system
Authors: Hosseinnezhad P , Behnia S , Fathizadeh S 
Published: November 2020

Abstract
Photosynthesis is the most important photon-induced process to fuel the activities of the organism. In the current work, we have investigated the exciton energy transfer in a photosynthetic complex connected to a thermal bath using the quantum chaos approach. The statistical distribution of the energy levels of the system investigates a quasi-degeneracy level distribution and, therefore, a stable system. The system is sensitive to the environmental effects, and the Hamiltonian parameters. Among the practical factors, we have studied the effect of temperature and solvent on the chlorosome system. At low temperatures, the Izrailev distribution is quasi-Poisson and the general behavior of the system approaches to a nearly localized state. Gradually, with increasing temperature, it corresponds to the Poisson state and shows an improvement in exciton transmission. In the presence of a solvent, at low solvent frequency, via the increasing the temperature, the system changes its behavior from the localized state to the transition state. But, by increasing the frequency, the system presents the opposite behavior: with increasing the temperature, the system becomes more localized. Accordingly, the most appropriate conditions for exciton energy transfer in the chlorosome system are low-frequency solvent and high-temperature. To compare the temperature effect on different parts of the photosynthetic system, we have studied the temperature effect on the FMO complex conductivity, which shows the increase in conductivity and exciton energy transfer with increasing the temperature. Modulation of transport properties in the system provides the potential application in the nanoscale biomaterial devices.
Degree-ordered-percolation on uncorrelated networks
Authors: Caligiuri Annalisa , Castellano Claudio 
Published: November 2020

Abstract
We analyze the properties of degree-ordered percolation (DOP), a model in which the nodes of a network are occupied in degree-descending order. This rule is the opposite of the much studied degree-ascending protocol, used to investigate resilience of networks under intentional attack, and has received limited attention so far. The interest in DOP is also motivated by its connection with the susceptible-infected-susceptible (SIS) model for epidemic spreading, since a variation of DOP is related to the vanishing of the SIS transition for random power-law degree-distributed networks P(k) ∼ k
−γ
. By using the generating function formalism, we investigate the behavior of the DOP model on networks with generic value of γ and we validate the analytical results by means of numerical simulations. We find that the percolation threshold vanishes in the limit of large networks for γ ⩽ 3, while it is finite for γ > 3, although its value for γ between 3 and 4 is exceedingly small and preasymptotic effects are huge. We also derive the critical properties of the DOP transition, in particular how the exponents depend on the heterogeneity of the network, determining that DOP does not belong to the universality class of random percolation for γ ⩽ 3.
A novel vertical aligned mesoporous silica coated nanohydroxyapatite particle as efficient dexamethasone carrier for potential application in osteogenesis
Authors: Jia Sen , Liu Yan , Ma Zhiwei , Liu Changkui , Chai Juan , Li Zixia , Song Wen , Hu Kaijin 
Published: November 2020

Abstract
Bone defect is a common problem and inducing osteoblasts differentiation is the key process for the regenerative repair. Recently, the mesoporous silica (MS) coated nanohydroxyapatite (nHA) particles (nHA-MS) has shown enhanced intrinsic potency for bone regeneration, whereas whether the osteogenesis potency can be further enhanced after drug delivery has not been investigated. In this study, the nHA-MS was fabricated by a novel biphase stratification growth way. The cytotoxicity in MC3T3-E1 was validated by MTT assay, apoptosis analysis and cell cycle examination. The cell uptake was observed by confocal laser scanning microscope and transmission electron microscope respectively. After adsorption with dexamethasone (DEX), the osteogenic differentiation was determined both in vitro and in vivo. The synthesized nHA-MS showed a core–shell structure that the nanorod-like nHA was coated by a porous MS shell (∼5 nm pores diameter, ∼50 nm thickness). A dose-dependent cytotoxicity was observed and below 10 µg ml−1 was a safe concentration. The nHA-MS also showed efficient cell uptake efficiency and more efficient in DEX loading and release. After DEX adsorption, the nanoparticles exhibited enhanced osteogenic induction in MC3T3-E1 and rat calvarial bone defect regeneration. In conclusion, the nHA-MS is a favorable platform for drug delivery to obtain more enhanced osteogenesis capabilities.
Fourth Painlevé and Ermakov equations: quantum invariants and new exactly-solvable time-dependent Hamiltonians
Authors: Zelaya K , Marquette I , Hussin V 
Published: November 2020

Abstract
In this work, we introduce a new realization of exactly-solvable time-dependent Hamiltonians based on the solutions of the fourth Painlevé and the Ermakov equations. The latter is achieved by introducing a shape-invariant condition between an unknown quantum invariant and a set of third-order intertwining operators with time-dependent coefficients. New quantum invariants are constructed after adding a deformation term to the well-known quantum invariant of the parametric oscillator. Such a deformation depends explicitly on time through solutions of the Ermakov equation, a property that simultaneously ensures the regularity of the new time-dependent potentials at each time. The fourth Painlevé equation appears after introducing an appropriate reparametrization of the spatial coordinate and the time parameter, where the parameters of the fourth Painlevé equation dictate the spectral information of the quantum invariant. In this form, the eigenfunctions of the third-order ladder operators lead to several sequences of solutions to the Schrödinger equation, which are determined in terms of the solutions of the Riccati equation, Okamoto polynomials, and nonlinear bound states of the derivative nonlinear Schrödinger equation. Remarkably, it is noticed that the solutions in terms of the nonlinear bound states lead to a quantum invariant with equidistant eigenvalues, which contains both an finite-dimensional and an infinite-dimensional sequences of eigenfunctions. The resulting family of time-dependent Hamiltonians is such that, to the authors’ knowledge, have been unnoticed in the literature of stationary and nonstationary systems.
InGaN quantum dots with short exciton lifetimes grown on polar c-plane by metal-organic chemical vapor deposition
Authors: Zhao Chunyu , Tang Chak Wah , Cheng Guanghui , Wang Jiannong , Lau Kei May 
Published: November 2020

Abstract
An investigation of self-assembled polar InGaN quantum dots (QDs) on c-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD) is reported. The radiative exciton lifetime is measured by time-resolved photoluminescence at a low temperature of 18 K, where the non-radiative recombination can be negligible. A mono-exponential exciton decay with a radiative exciton lifetime of 480 ps for uncapped QDs is revealed. With an optimized GaN capping layer grown by a two-step method, a radiative exciton lifetime of 707 ps for the capped QDs is preserved. The short radiative exciton lifetime is much shorter than that for previously studied polar QDs and is even comparable with those grown along non-polar QDs, which is strong evidence of the reduction of built-in fields in these polar InGaN QDs.
Dense positrons and γ-rays generation by lasers interacting with convex target
Authors: YASEN Nureli , XIE Baisong , LIU Weiyuan 
Published: November 2020

Abstract
We use quantum electrodynamics particle-in-cell simulation to study the generation of dense electron–positron plasma and strong γ-ray bursts in counter-propagating laser beam interactions with two different solid targets, i.e. planar (type I) and convex (type II). We find that type II limits fast electron flow most effectively. while the photon density is increased by about an order of magnitude and energy by approx. 10%–20% compared with those in type I target. γ-photon source with an ultrahigh peak brilliance of 2 × 1025 photons/s/mm2/mrad2/0.1% BW is generated by nonlinear Compton scattering process. Furthermore, use of type II target increases the positron density and energy by 3 times and 32% respectively, compared with those in type I target. In addition, the conversion efficiencies of total laser energy to γ-rays and positrons of type II are improved by 13.2% and 9.86% compared with type I. Such improvements in conversion efficiency and positron density are envisaged to have practical applications in experimental field.
Improving the reliability of conductive atomic force microscopy-based electrical contact resistance measurements
Authors: Sumaiya Saima A , Martini Ashlie , Baykara Mehmet Z 
Published: November 2020

Abstract
Electrical contact resistance (ECR) measurements performed via conductive atomic force microscopy (C-AFM) suffer from poor reliability and reproducibility. These issues are due to a number of factors, including sample roughness, contamination via adsorbates, changes in environmental conditions such as humidity and temperature, as well as deformation of the tip apex caused by contact pressures and/or Joule heating. Consequently, ECR may vary dramatically from measurement to measurement even on a single sample tested with the same instrument. Here we present an approach aimed at improving the reliability of such measurements by addressing multiple sources of variability. In particular, we perform current-voltage spectroscopy on atomically flat terraces of highly oriented pyrolytic graphite (HOPG) under an inert nitrogen atmosphere and at controlled temperatures. The sample is annealed before the measurements to desorb adsorbates, and conductive diamond tips are used to limit tip apex deformation. These precautions lead to measured ECR values that follow a Gaussian distribution with significantly smaller standard deviation than those obtained under conventional measurement conditions. The key factor leading to this improvement is identified as the switch from ambient conditions to a dry nitrogen atmosphere. Despite these improvements, spontaneous changes in ECR are observed during measurements performed over several minutes. However, it is shown that such variations can be suppressed by applying a higher normal load.
Effect of the COVID-19 lockdown on disease recognition and utilisation of healthcare services in the older population in Germany: a cross-sectional study
Authors: Michalowsky Bernhard , Hoffmann Wolfgang , Bohlken Jens , Kostev Karel 
Published: November 2020

Abstract

Background
There is little evidence about the utilisation of healthcare services and disease recognition in the older population, which was urged to self-isolate during the COVID-19 lockdown.

Objectives
We aimed to describe the utilisation of physician consultations, specialist referrals, hospital admissions and the recognition of incident diseases in Germany for this age group during the COVID-19 lockdown.

Design
Cross-sectional observational study.

Setting
1,095 general practitioners (GPs) and 960 specialist practices in Germany.

Subjects
2.45 million older patients aged 65 or older.

Methods
The number of documented physician consultations, specialist referrals, hospital admissions and incident diagnoses during the imposed lockdown in 2020 was descriptively analysed and compared to 2019.

Results
Physician consultations decrease slightly in February (−2%), increase before the imposed lockdown in March (+9%) and decline in April (−18%) and May (−14%) 2020 compared to the same periods in 2019. Volumes of hospital admissions decrease earlier and more intensely than physician consultations (−39 versus −6%, respectively). Overall, 15, 16 and 18% fewer incident diagnoses were documented by GPs, neurologists and diabetologists, respectively, in 2020. Diabetes, dementia, depression, cancer and stroke were diagnosed less frequently during the lockdown (−17 to −26%), meaning that the decrease in the recognition of diseases was greater than the decrease in physician consultations.

Conclusion
The data suggest that organisational changes were adopted quickly by practice management but also raise concerns about the maintenance of routine care. Prospective studies should evaluate the long-term effects of lockdowns on patient-related outcomes.
Lorna Finlayson on Political Philosophy and Immigration: A Reply
Authors: Miller David 
Published: November 2020

Abstract
Replying to Finlayson (2020), I defend analytic political philosophy from the charge that, by ignoring their historical context, it fails to grasp what is really at stake in the case of issues such as immigration. I also defend my own work on that topic from the charge that it is implicitly racist by virtue of using arguments capable of being appropriated by racists.
miqoGraph: fitting admixture graphs using mixed-integer quadratic optimization
Authors: Yan Julia , Patterson Nick , Narasimhan Vagheesh M 
Published: November 2020

Abstract

Summary
Admixture graphs represent the genetic relationship between a set of populations through splits, drift and admixture. In this article, we present the Julia package miqoGraph, which uses mixed-integer quadratic optimization to fit topology, drift lengths and admixture proportions simultaneously. Through applications of miqoGraph to both simulated and real data, we show that integer optimization can greatly speed up and automate what is usually an arduous manual process.

Availability and implementation
https://github.com/juliayyan/PhylogeneticTrees.jl.

Supplementary information
Supplementary data are available at Bioinformatics online.
A framework for modeling epistatic interaction
Authors: Blumenthal David B , Baumbach Jan , Hoffmann Markus , Kacprowski Tim , List Markus 
Published: November 2020

Abstract

Motivation
Recently, various tools for detecting single nucleotide polymorphisms (SNPs) involved in epistasis have been developed. However, no studies evaluate the employed statistical epistasis models such as the χ2-test or quadratic regression independently of the tools that use them. Such an independent evaluation is crucial for developing improved epistasis detection tools, for it allows to decide if a tool’s performance should be attributed to the epistasis model or to the optimization strategy run on top of it.

Results
We present a protocol for evaluating epistasis models independently of the tools they are used in and generalize existing models designed for dichotomous phenotypes to the categorical and quantitative case. In addition, we propose a new model which scores candidate SNP sets by computing maximum likelihood distributions for the observed phenotypes in the cells of their penetrance tables. Extensive experiments show that the proposed maximum likelihood model outperforms three widely used epistasis models in most cases. The experiments also provide valuable insights into the properties of existing models, for instance, that quadratic regression perform particularly well on instances with quantitative phenotypes.

Availability and implementation
The evaluation protocol and all compared models are implemented in C++ and are supported under Linux and macOS. They are available at https://github.com/baumbachlab/genepiseeker/, along with test datasets and scripts to reproduce the experiments.

Supplementary information
Supplementary data are available at Bioinformatics online.
Cerebellar contributions to cognition in corticobasal syndrome and progressive supranuclear palsy
Authors: Tse Nga Yan , Chen Yu , Irish Muireann , Cordato Nicholas J , Landin-Romero Ramon , Hodges John R , Piguet Olivier , Ahmed Rebekah M 
Published: November 2020

Abstract
Mounting evidence suggests an association between cerebellar atrophy and cognitive impairment in the main frontotemporal dementia syndromes. In contrast, whether cerebellar atrophy is present in the motor syndromes associated with frontotemporal lobar degeneration (corticobasal syndrome and progressive supranuclear palsy) and the extent of its contribution to their cognitive profile remain poorly understood. The current study aimed to comprehensively chart profiles of cognitive impairment in relation to cerebellar atrophy in 49 dementia patients (corticobasal syndrome = 33; progressive supranuclear palsy = 16) compared to 33 age-, sex- and education-matched healthy controls. Relative to controls, corticobasal syndrome and progressive supranuclear palsy patients demonstrated characteristic cognitive impairment, spanning the majority of cognitive domains including attention and processing speed, language, working memory, and executive function with relative preservation of verbal and nonverbal memory. Voxel-based morphometry analysis revealed largely overlapping patterns of cerebellar atrophy in corticobasal syndrome and progressive supranuclear palsy relative to controls, primarily involving bilateral Crus II extending into adjacent lobules VIIb and VIIIa. After controlling for overall cerebral atrophy and disease duration, exploratory voxel-wise general linear model analysis revealed distinct cerebellar subregions differentially implicated across cognitive domains in each patient group. In corticobasal syndrome, reduction in grey matter intensity in the left Crus I was significantly correlated with executive dysfunction. In progressive supranuclear palsy, integrity of the vermis and adjacent right lobules I–IV was significantly associated with language performance. These results are consistent with the well-established role of Crus I in executive functions and provide further supporting evidence for vermal involvement in cognitive processing. The current study presents the first detailed exploration of the role of cerebellar atrophy in cognitive deficits in corticobasal syndrome and progressive supranuclear palsy, offering insights into the cerebellum’s contribution to cognitive processing even in neurodegenerative syndromes characterized by motor impairment.