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Paper‐based sensors, microfluidic platforms, and electronics have attracted attention in the past couple of decades because they are flexible, can be recycled easily, environmentally friendly, and inexpensive. Here we report a paper‐based potentiometric sensor to detect the whole Zika virus with a minimum sensitivity of 0.26 nV/Zika and a minimum detectable signal (MDS) of 2.4x107 Zika. Our paper sensor works very similar to a P‐N junction where a junction is formed between two different regions with different electrochemical potentials on the paper. These two regions with slightly different ionic contents, ionic species and concentrations, produce a potential difference given by the Nernst equation. Our paper sensor consists of 2‐3 mm x 10 mm segments of paper with conducting silver paint contact patches on two ends. The paper is dipped in a buffer solution containing aptamers designed to bind to the capsid proteins on Zika. We then added the Zika (in its own buffer) to the region close to one of the silver‐paint contacts. The Zika virus (40 nm diameter with 43 kDa or 7.1x10‐20 gm weight) became immobilized in the paper’s pores and bonded with the resident aptamers creating a concentration gradient. Atomic force microscopy and Raman spectroscopy were carried out to verify that both the aptamer and Zika become immobilized in the paper. The potential measured between the two silver paint contacts reproducibly became more negative upon adding the Zika. We also showed that a Liquid Crystalline Display (LCD) powered by the sensor can be used to read the sensor output.

The appearance or printing quality of paper surfaces is mostly characterized by their glossiness, measured with a glossmeter as specular reflectance. The gloss properties of a base paper substrate can be improved after application of a poly(styrene-co-maleimide) nanoparticle coating under pure conditions or in the presence of different vegetable oils. The specular gloss properties of 11 different nanoparticle paper coatings have been determined under 75 degrees and 85 degrees incident light angles, with good relation between values along parallel (machine) and perpendicular (transverse) direction. The gloss properties for the different coatings have been further related to the surface topography. Therefore, the statistical and spatial surface roughness parameters have been studied in detail at two length scales including non-contact profilometry (1 x 1 mm(2)) and atomic force microscopy (2 x 2 m(2)). Based on values of the Rayleigh parameter for non-contact profilometry, the surfaces can be considered as optically rough. The gloss values cannot be directly related to statistical surface roughness parameters. Otherwise, an experimental power-law model for gloss has been proposed as a function of (/Sq) with correlation length and root-mean-square roughness Sq. A best-fit model illustrates that gloss properties of various nanoparticle paper coatings mainly relate to the spatial surface roughness parameters determined from non-contact profilometry. (c) 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 596-610, 2016

We introduce a new method for evaluation of sparkle of the combination of display and AG-layer by application of a weighting of the Fourier amplitudes of the random luminance modulations that are perceived as sparkle, according to the contrast sensitivity function of the human visual system. This new approach provides improved sensitivity to small sparkle variations, better control of parasitic low frequency components caused by non-uniformities of display illumination and an improved match to visual ratings with subtle differences in the low sparkle region.

Problem formulations and solution procedures of production planning and inventory management for manufacturing systems under uncertainties is discussed. Markov decision processes and controlled Markovian dynamic systems are used in the models. Considering an inventory problem in discrete time and formulating it by a finite-state Markov chain lead to a Markov decision process model. Using the policy-improvement algorithm yields the optimal inventory policy. In controlled dynamic system modeling, the random demand and capacity processes involved in planning are described by two finite-state continuous-time Markov chains. Such an approach enables us to embed the randomness in the differential equations of the system. The optimal production rates that minimize an expected cost are obtained by numerically solving the corresponding Hamilton–Jacobi–Bellman (HJB) equations. To overcome the so-called curse of dimensionality, frequently encountered in computation, we resort to a hierarchical approach. Illustrative examples using data collected from a large paper manufacturer are provided. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2877–2890, 2004

The microscopic origin of the negative bias and illumination stress (NBIS) instability of amorphous oxide semiconductors is revealed by first-principles calculations. We find that the excited holes during the stresses generate O2 peroxide defects in the oxide channel with increasing the Fermi level. The peroxide defects exhibit meta-stability.

Aims This study aimed to explore the experience of individuals who claimed to be COVID‐19 positive via their Twitter feeds. Background Public social media data are valuable to understanding people's experiences of public health phenomena. To improve care to those with COVID‐19, this study explored themes from Twitter feeds, generated by individuals who self‐identified as COVID‐19 positive. Design This study utilized a descriptive design for text analysis for social media data. Methods This study analysed social media text retrieved by tweets of individuals in the United States who self‐reported being COVID‐19 positive and posted on Twitter in English between April 2, 2020, and April 24, 2020. In extracting embedded topics from tweets, we applied topic modelling approach based on latent Dirichlet allocation and visualized the results via LDAvis, a related web‐based interactive visualization tool. Results Three themes were mined from 721 eligible tweets: (i) recognizing the seriousness of the condition in COVID‐19 pandemic; (ii) having symptoms of being COVID‐19 positive; and (iii) sharing the journey of being COVID‐19 positive. Conclusion Leveraging the knowledge and context of study themes, we present experiences that may better reflect patient needs while experiencing COVID‐19. The findings offer more descriptive support for public health nursing and other translational public health efforts during a global pandemic., Summary statement What is already known about this topic? Social media data can be used to predict potential outbreak areas, which has been beneficial to informing decision makers.Public opinions about the pandemic can be extracted from social media data, which helps understand patients and the public's experiences and potential needs.In the early stage of the novel COVID‐19 pandemic in the United States, little was known about the experiences and needs of those with COVID‐19. What this paper adds? Individuals who claimed to be COVID‐19 positive used the social media platform (e.g., Twitter) as a broader communication strategy to their social networks during the social distancing phase at the early stage of the COVID‐19 pandemic.Key messages delivered through the social media included warning their family, friends and network take the pandemic seriously, expressing their symptom profiles related to COVID‐19 and sharing their journey of being a COVID‐19 patient.Although latent Dirichlet allocation may be underutilized in nursing research, valuable information regarding mental health issues can be discovered and amplified from the social media data using this methodology. The implications of this paper: Substantial evidence encourages the public health community to engage in more detailed mental health screening of patients with COVID‐19.By leveraging the knowledge and context of the social media threads (e.g., patient perspective), there is ample opportunity for more focal and descriptive public health interventions to mitigate the stress and uncertainty of a pandemic.

Introduction The objective of this study was to examine the relationship between trauma volume and alcohol prohibition during the COVID‐19 lockdown in South Africa. Methods This was a retrospective analysis of trauma volume from Worcester Regional Hospital in South Africa from 1 January to 28 December 2020. We compared total volume and incidence rates during five calendar periods; one when alcohol sales were allowed as per normal and four when alcohol sales were completely or partially banned. Poisson regression was used to model differences between alcohol ban and non‐ban periods. Results During the first period (pre‐COVID‐19, no ban), the trauma admission rate was 95 per 100 days, compared to 39 during the second period (complete ban 1), 74 during the third period (partial ban 1), 40 during the fourth period (complete ban 2) and 105 during the fifth period (partial ban 2). There was a 59–69% decrease in trauma volume between the no ban and complete ban 1 periods. When alcohol sales were partially reinstated, trauma volume significantly increased by 83–90% then dropped again by 39–46% with complete ban 2. By the second half of 2020, when alcohol sales were partially allowed again (partial ban 2), trauma volume increased by 163–250%, thus returning to pre‐COVID‐19 levels. Discussion and Conclusions Our study demonstrates a clear trend of decreased trauma volume during periods of complete alcohol prohibition compared to non‐ and partial alcohol bans. This finding suggests that temporary alcohol bans can be used to decrease health facility traffic during national emergencies.

The combination of the laser and optical diffraction analysis provides a powerful tool for the determination of fiber orientation distribution in any paper sheet of basis weight low enough to be translucent to the laser beam. The coherent light beam from the laser is diffracted by the sample. It undergoes a Fourier transform from which the orientation distributions can be calculated. Measurements were made on 14 different samples of various degrees of orientation, including an essentially random handsheet as a control. The cross-direction/machine direction elastic modulus ratios of the samples were found to correlate well with the distribution functions fitted to the orientation data. The correlation curve was S-shaped, with a drastic drop in the modulus ration in the medium range of fiber orientation.

Backgrounds and aims This article develops a Specialty Intensity Score, which uses patient diagnosis codes to estimate the number of specialist physicians a patient will need to access. Conceptually, the score can serve as a proxy for a patient's need for care coordination across doctors. Such a measure may be valuable to researchers studying care coordination practices for complex patients. In contrast with previous comorbidity scores, which focus primarily on mortality and utilization, this comorbidity score approximates the complexity of a patient's the interaction with the health care system. Methods We use 2015 inpatient claims data from the Centers for Medicare and Medicaid Services to model the relationship between a patient's diagnoses and physician specialty usage. We estimate usage of specialist doctors by using a least absolute shrinkage and selection operator Poisson model. The Specialty Intensity Score is then constructed using this predicted specialty usage. To validate our score, we test its power to predict the occurrence of patient safety incidents and compare that with the predictive power of the Charlson comorbidity index. Results Our model uses 127 of the 279 International Classification of Disease, 10th Revision, Clinical Modification (ICD‐10‐CM) diagnosis subchapters to predict specialty usage, thus creating the Specialty Intensity Score. This score has significantly greater power in predicting patient safety complications than the widely used Charlson comorbidity index. Conclusion The Specialty Intensity Score developed in this article can be used by health services researchers and administrators to approximate a patient's need for care coordination across multiple specialist doctors. It, therefore, can help with evaluation of care coordination practices by allowing researchers to restrict their analysis of outcomes to the patients most impacted by those practices.

Rationale, aims, and objectives The aim of this study was to focus attention on episiotomy practice in Romanian maternity units in order to identify factors associated with the very high rate of the procedure in Romania and to consider strategies to reduce it. Methods In this clustered cross‐sectional study, a total of 11 863 patients were recorded in eight Romanian maternity units to assess the prevalence of episiotomy. A random effects Poisson model was used to estimate the prevalence rate in univariate and multivariate models. Results Among the 11 863 patients included for analysis, 8475 (71.4%) had an episiotomy. The prevalence of episiotomy was 92.7% for the first vaginal birth, 73.2% for the second vaginal birth, and 35% for the third vaginal birth. The overall rate of suturing was higher than the episiotomy rate for all patients (total rate 79.2%). The likelihood of exiting the maternity ward with an intact perineum after the first vaginal birth was less than 5% at the first vaginal birth. Conclusions In conclusion, routine episiotomy is the norm in Romanian maternity units, with episiotomy rates among the highest in Europe. Episiotomy use is mainly driven by local professional norms, experiences, previous training, and practitioners' decisions rather than evidence, guidelines, or variations in patient needs at the time of vaginal birth.

Central obesity may contribute to the development of hypertension in youths with diabetes. The SEARCH for Diabetes in Youth Study followed 1518 youths with type 1 diabetes (T1D) and 177 with type 2 diabetes (T2D) diagnosed when

Field effect transistors (FETs) based on 2D materials are of great interest for applications in ultrathin electronic and sensing devices. Here we demonstrate the possibility to add optical switchability to graphene FETs (GFET) by functionalizing the graphene channel with optically switchable azobenzene molecules. The azobenzene molecules were incorporated to the GFET channel by building a van der Waals heterostructure with a carbon nanomembrane (CNM), which is used as a molecular interposer to attach the azobenzene molecules. Under exposure with 365 nm and 455 nm light, azobenzene molecules transition between cis and trans molecular conformations, respectively, resulting in a switching of the molecular dipole moment. Thus, the effective electric field acting on the GFET channel is tuned by optical stimulation and the carrier density is modulated., Optically switchable graphene FET: Via van der Waals assembly of an approximately 1 nm thick azobenzene functionalized molecular nanosheets with single layer graphene, optically responsive field‐effect transistors are demonstrated. The electrical carrier density of these devices can be modulated using optical stimuli, 365 nm and 455 nm light.

Patterned functionalization can, on the one hand, open the band gap of graphene and, on the other hand, program demanding designs on graphene. The functionalization technique is essential for graphene‐based nanoarchitectures. A new and highly efficient method was applied to obtain patterned functionalization on graphene by mild fluorination with spatially arranged AgF arrays on the structured substrate. Scanning Raman spectroscopy (SRS) and scanning electron microscopy coupled with energy‐dispersive X‐ray spectroscopy (SEM‐EDS) were used to characterize the functionalized materials. For the first time, chemical patterning on the bottom side of graphene was realized. The chemical nature of the patterned functionalization was determined to be the ditopic scenario with fluorine atoms occupying the bottom side and moieties, such as oxygen‐containing groups or hydrogen atoms, binding on the top side, which provides information about the mechanism of the fluorination process. Our strategy can be conceptually extended to pattern other functionalities by using other reactants. Bottom‐side patterned functionalization enables utilization of the top side of a material, thereby opening up the possibilities for applications in graphene‐based devices., Bottoms up! Patterned bottom‐side functionalization of graphene was realized using a 2D substrate patterning method. A very high degree of functionalization and patterned fluorination are demonstrated. Ditopic functionalization is observed with fluorine atoms on the bottom side and moieties, such as oxygen‐containing groups or hydrogen atoms, on the top side.

Despite extensive research on graphene, there are still lacks of understanding the structural changes under harsh stress environments such as high current in uncontrolled atmosphere. Investigating the structural changes of graphene patterned into device at high temperature would be important as the electrical current path of graphene becomes narrower and thus stronger in heat dissipation. In this paper, we performed a comparative study of the structural and electronical changes of graphene for as-grown graphene and patterned graphene in a microbridge shape heated up to 500 °C in air or Ar. While the as-grown graphene heated in air or Ar was nearly free from the structural changes, the microbridge graphene exhibited strong structural changes after annealing in Ar, i.e. the broadening in the G and the 2D peaks remained even after cooling back to 30 °C. On the other hand, the microbridge graphene heated in air was observed to release stress probably due to formation of vacancies by oxygen adsorption. The different behavior of microbridge graphene heated in Ar from that of as-grown graphene in the same condition is obvious. This means that graphene in microscopic devices should be treated differently from the as-grown graphene. Copyright © 2017 John Wiley & Sons, Ltd.

In this paper, we characterize capacity region of the Gaussian doubly dirty two-way channel TWC with partial side information at users, where there are two additive interference signals that, although similar to the channel noise sequences, corrupt the transmitted signals but are non-causally and partially known to the users. First, by employing adaptation considering the previously received signals in encoding process, we derive an adaptive outer bound on the capacity region of the channel. Then, we utilize lattice strategies and obtain a non-adaptive inner bound that coincides with the adaptive outer bound and hence gives the capacity region. This also shows that for the doubly dirty TWC with partial side information, adaptation is useless and cannot increase the capacity region. Finally, we prove that Costa's dirty paper coding is optimal like lattice strategies and therefore, the Gaussian doubly dirty TWC is an instance of multi-user channels in which lattice strategy and Costa's strategy have the same performance from the capacity region perspective. It is worth noting that our results subsume the previous related works as special cases. Copyright © 2014 John Wiley & Sons, Ltd.

A highly periodic electrostatic potential, even though established in van der Waals bonded organic crystals, is essential for the realization of a coherent band electron system. While impurity doping is an effective chemical operation that can precisely tune the energy of an electronic system, it always faces an unavoidable difficulty in molecular crystals because the introduction of a relatively high density of dopants inevitably destroys the highly ordered molecular framework. In striking contrast, a versatile strategy is presented to create coherent 2D electronic carriers at the surface of organic semiconductor crystals with their precise molecular structures preserved perfectly. The formation of an assembly of redox‐active molecular dopants via a simple one‐shot solution process on a molecularly flat crystalline surface allows efficient chemical doping and results in a relatively high carrier density of 1013 cm−2 at room temperature. Structural and magnetotransport analyses comprehensively reveal that excellent carrier transport and piezoresistive effects can be obtained that are similar to those in bulk crystals., The surface of organic single crystals is chemically doped via a simple one‐shot solution process, and the resulting 2D electronic system with a high carrier density serves as a multi‐functional, conductive nanosheet.

Lead halide perovskites (LHPs) have become a promising alternative for a wide range of optoelectronic devices, thanks to their solution‐processability and impressive optical and electrical properties. More recently, LHPs have been investigated in magneto‐optic studies and have exhibited spin‐polarized emission, photoinduced magnetization, and long spin lifetimes. Here, the viability of methylammonium lead bromide (MAPbBr3) single crystals as solution‐processed Faraday rotators is demonstrated. Compared to terbium gallium garnet, the industry standard in the visible, it is found that MAPbBr3 exhibits Verdet constants (i.e., strength of Faraday effect) of similar or greater magnitude (up to 2.5x higher), with lower temperature dependence. Due to its low trap absorption, it is calculated that an optical isolator made from MAPbBr3, with appropriate antireflection coatings, should reach ≈95% transmission and achieve 40 dB isolation for incoming powers of over 2 W. It is also shown that the Verdet constant of MAPbBr3 can be calculated accurately from its dispersion in refractive index, allowing the possibility to predict similar effects in other perovskite materials., Strong Faraday rotation is demonstrated for methylammonium lead bromide (MAPbBr3) single crystals. Coupled with low defect density, they are poised to represent a solution‐processed alternative for Faraday rotator applications, such as optical isolators and optical switches. Additionally, their Faraday rotation fits well with classical theory, allowing prediction of other perovskites for this application.

SUMMARY In this paper, a new practical dirty paper coding scheme and its extension is proposed for interference mitigation of a single TV broadcast station in uplink and downlink of a cognitive radio network using both a single secondary user (SU) and multiple SU scenarios. In the single SU scenario, which is called interference cognitive radio channel, derived simulation results show that the transmission rate of the SU archives the capacity of an AWGN channel with the cost of a 2.5 dB extra signal-to-noise ratio. In the sequel, the proposed scheme is extended to a multiple SU scenario using direct sequence spread spectrum technique in both uplink and downlink considering a TV band. Derived simulation results show that the number of supportable SUs in our proposed scheme increases to a fully loaded scenario of the same multiuser direct sequence spread spectrum system. Copyright © 2012 John Wiley & Sons, Ltd.

A novel high-efficiency photoelectrode (Fe2O3/reduced graphene oxide/CdS) built from heterostructure and conductive scaffold has been successfully designed and synthesized. Reduced graphene oxide works as a “bridge” which benefits for electron and hole transport. The obtained heterostructure photoelectrodes were systematically characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The photoconversion efficiency (η) and photocurrent densities vs. time (I-t) curves responding to monochromatic lights have been further investigated in-depth, which reveals that introduction of CdS and reduced graphene oxide played an important role in the enhancement of photoelectrochemical performance.

In situ Raman spectroelectrochemistry has been applied to study chemical vapor-deposition-grown single-layer graphene membrane on a patterned SiO2/Si substrate. The SiO2/Si substrate is known to dope graphene, thus the substrate can significantly influence the properties of the graphene during electrochemical charging. We analyzed the change of the Raman intensity of the G mode as a function of electrode potential for a single-layer graphene membrane and we compared the results to those obtained for the same graphene sample on a substrate. Because of the elimination of the influence of a supporting substrate we have been able to achieve more efficient doping of graphene by applied electrode potentials.

Suppressing the recombination of photogenerated charges is one of the most important routes for enhancing the catalytic performance of semiconductor photocatalysts. In addition to the built‐in field produced by semiconductor heterostructures and the photo‐electrocatalysis realized by applying an external electrical potential to photocatalysts assembled on electrodes, other strategies are waiting to be scientifically explored and understood. In this work, a Lorentz force–assisted charge carrier separation enhancement strategy is reported to improve the photocatalytic efficiency by applying a magnetic field to a photocatalytic system. The photocatalytic efficiency can be improved by 26% just by placing a permanent magnet beneath the normal photocatalytic system without any additional power supply. The mechanism by which the Lorentz force acts oppositely on the photogenerated electrons and holes is introduced, resulting in the suppression of the photoinduced charge recombination. This work provides insights into the specific role of the Lorentz force in suppressing the recombination of electron–hole pairs in their initial photogenerated states. This suppression would increase the population of charge carriers that would subsequently be transported in the semiconductor. It is believed that this strategy based on magnetic effects will initiate a new way of thinking about photoinduced charge separation.

Background and Objectives The recent establishment of the National Healthcare Safety Network Hemovigilance Module in the United States affords an opportunity to compare results with those of other developed nations. Materials and Methods Using data from national haemovigilance systems, reactions associated with red blood cell (RBC) transfusion and residual risks of transfusion-transmitted infectious diseases were assembled from 17 nations. Country-specific rates of adverse events were pooled using random-effects Poisson regression. Results Febrile non-haemolytic and delayed serologic transfusion reactions were the most frequent adverse events reported after RBC transfusion, occurring in 26 patients per 100 000 RBC units and 25 patients per 100 000 RBC units administered, respectively. Rates of allergic, febrile non-haemolytic and delayed haemolytic transfusion reactions in the United States were significantly greater than the pooled rates from other countries. Frequencies of adverse events generated from the national haemovigilance programme in the United States were considerably lower than when obtained through active surveillance. Conclusion Haemovigilance reports of adverse events in the United States are comparable to, or greater than, reports from other developed countries. Rates generated from haemovigilance programmes are lower than those obtained through active surveillance. The lack of universal leucoreduction of RBC units may be a contributing factor to the higher rate of some adverse events in the United States.

The operation of a paper machine relies on the close monitoring and control of several integrated units to ensure a high quality paper with the required specifications. In this paper, the retention control system in the wet-end of a paper machine is considered. The control objective is to maximize the retention of fines and fibres in the paper sheet to prevent the accumulation of micro particles in the water system. We present an adaptive extremum-seeking scheme for the optimization and control of retention in the wet-end of a paper machine. An adaptive learning technique is introduced to construct an algorithm that drives the system to the optimal retention value. Lyapunov's stability theory is used in the design of the extremum-seeking controller structure and the development of the parameter learning laws. The performance of the technique is illustrated via simulations based on a first-principles dynamic model developed previously for a micro-particulate system.

This paper considers a synthesis of graphene flakes on the Ni surface by vacuum thermal treatment of the “sandwich” a-SiC/Ni multilayer deposited on silicon wafer by magnetron sputtering technique. Lateral size of graphene flake is estimated to be about hundreds of microns while thickness estimated by Raman scattering varied from one to few layers. Atom force microscopy (AFM) is not able to detect graphene flakes in regime of surface topology examination due to large roughness of Ni surface. Employment of scanning Kelvin probe force microscopy (SKPFM) demonstrates a correlation of surface potential and graphene flakes visible by optical microscopy. Moreover, the SKPFM allows to detect the graphene layer even in case of absence of optical contrast from single graphene layer on nickel surface. Using of KPFM the potential differences between Ni and graphene is determined. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Please cite this paper as: Schanzer et al. (2012) Statistical estimates of respiratory admissions attributable to seasonal and pandemic influenza for Canada. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12011. Background The number of admissions to hospital for which influenza is laboratory confirmed is considered to be a substantial underestimate of the true number of admissions due to an influenza infection. During the 2009 pandemic, testing for influenza in hospitalized patients was a priority, but the ascertainment rate remains uncertain. Methods The discharge abstracts of persons admitted with any respiratory condition were extracted from the Canadian Discharge Abstract Database, for April 2003–March 2010. Stratified, weekly admissions were modeled as a function of viral activity, seasonality, and trend using Poisson regression models. Results An estimated 1 out of every 6·4 admissions attributable to seasonal influenza (2003–April 2009) were coded to J10 (influenza virus identified). During the 2009 pandemic (May–March 2010), the influenza virus was identified in 1 of 1·6 admissions (95% CI, 1·5–1·7) attributed to the pandemic strain. Compared with previous H1N1 seasons (2007/08, 2008/09), the influenza-attributed hospitalization rate for persons

Purpose The diffusion tensor model assumes Gaussian diffusion and is widely applied in cardiac diffusion MRI. However, diffusion in biological tissue deviates from a Gaussian profile as a result of hindrance and restriction from cell and tissue microstructure, and may be quantified better by non-Gaussian modeling. The aim of this study was to investigate non-Gaussian diffusion in healthy and hypertrophic hearts. Methods Thirteen rat hearts (five healthy, four sham, four hypertrophic) were imaged ex vivo. Diffusion-weighted images were acquired at b-values up to 10,000 s/mm2. Models of diffusion were fit to the data and ranked based on the Akaike information criterion. Results The diffusion tensor was ranked best at b-values up to 2000 s/mm2 but reflected the signal poorly in the high b-value regime, in which the best model was a non-Gaussian “beta distribution” model. Although there was considerable overlap in apparent diffusivities between the healthy, sham, and hypertrophic hearts, diffusion kurtosis and skewness in the hypertrophic hearts were more than 20% higher in the sheetlet and sheetlet-normal directions. Conclusion Non-Gaussian diffusion models have a higher sensitivity for the detection of hypertrophy compared with the Gaussian model. In particular, diffusion kurtosis may serve as a useful biomarker for characterization of disease and remodeling in the heart. Magn Reson Med, 2016. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

In recent years, various van der Waals (vdW) materials have been used in implementing high‐performance photodetectors with high photoresponsivity over a wide detection range. However, in most studies reported so far, photodetection in the infrared (IR) region has not been achieved successfully. Although several vdW materials with narrow bandgaps have been proposed for IR detection, the devices based on these materials exhibit notably low photoresponsivity under IR light illumination. Here, highly efficient near‐infrared (NIR) photodetection based on the interlayer optical transition phenomenon in a vdW heterojunction structure consisting of ReS2 and ReSe2 is demonstrated. In addition, by applying the gate‐control function to the two‐terminal vdW heterojunction photodetector, the photoresponsivity is enhanced to 3.64 × 105 A W−1 at λ = 980 nm and 1.58 × 105 A W−1 at λ = 1310 nm. Compared to the values reported for previous vdW photodetectors, these results are the highest levels of photoresponsivity in the NIR range. The study offers a novel device platform for achieving high‐performance IR photodetectors.

The influence of the gradual polarization of a ferroelectric polymer on isotopically labeled bi-layer graphene has been investigated by Raman spectroscopy. The Raman frequencies of the 13C graphene modes are downshifted with respect to the Raman frequencies of 12C graphene, which enabled us to study the individual layer components of bi-layer graphene. The polarization of the ferroelectric polymer has a similar influence on the electron and hole concentration at the 13C graphene and the 12C graphene layer despite the 13C graphene layer being only in direct contact with the ferroelectric polymer. In the Raman experiment the doping of graphene was confirmed by a similar frequency shift of the G modes and similar changes in the intensities of the G′ modes during the electrochemical charging of the ferroelectric polymer.

A refined non-conforming triangular plate/shell element for geometric non-linear analysis of plates/shells using the total Lagrangian/updated Lagrangian approach is constructed in this paper based on the refined non-conforming element method for geometric non-linear analysis. The Allman's triangular plane element with vertex degrees of freedom and the refined triangular plate-bending element RT9 are used to construct the present element. Numerical examples demonstrate that the accuracy of the new element is quite high in the geometric non-linear analysis of plates/shells. Copyright © 2003 John Wiley & Sons, Ltd.

True colour measurements of wastewater samples, in terms of American Dye Manufacturers' Institute values, were used to evaluate the effectiveness of decolourisation of textile wastewater using spent green tea leaf powder waste. Raw wastewater samples with a true colour of 868 ADMI were used in the batch adsorption experiments. Results revealed that the true colour removal efficiency of the raw textile wastewater was high in acidic solution and at high temperature, indicating an endothermic nature of the system. The major functional groups of the green tea leaf powder waste involved in adsorption were identified by Fourier Transform-infrared spectroscopy analysis. Adsorption kinetic data were modelled using the modified Freundlich and intraparticle diffusion kinetics equations. Fitting results of the Langmuir adsorption isotherm showed that the adsorption capacity of the green tea leaf powder waste was 775 ADMI g−1, which is higher than that of powder activated carbon (526 ADMI g−1). The low activation energy values (13.9 kJ mol−1) suggested that adsorption was governed by a diffusion process and the reaction involved a physisorption mechanism. From the perspectives of waste utilisation, remarkable colour adsorption capacity and inexpensive and abundant availability, green tea leaf waste is an attractive alternative for decolourisaton of textile wastewater. Because high temperature favours colour removal, green tea leaf powder can be directly applied in raw textile wastewater treatment.

The applicability of FT-MIR/ATR spectroscopy (4000–400 cm−1) for the evaluation of early stages of autoxidation was examined for extra virgin olive oil samples (EVOO), which even after 12-month storage (dark, 23 ± 3°C) satisfied official limits for acidity, peroxide, K232 and K270 values. Changes in intensity values at 3470 cm−1 (hydroperoxide formation) and in values of various intensity ratios, namely A3006/2924, A3006/2853, A3006/1746, A3006/1465, A3006/1163, A1118/1097, A2853/1746, A2853/1417, A2853/1163, A2853/1118, A2853/1097, and A2853/723 (relevant to the degree of oil unsaturation) did not offer more information than the physicochemical criteria when examined one by one. Principal component – discriminant analysis of intensity values at 2924, 2853, 1746, 1465, 1163, 1118, 1097, and 723 cm−1 led to a 100, 91, and 54.5% correct classification for the 12, 6, and 0 months stored ones, respectively. Improvement in correct classification of the latter (73–91%) was obtained when the second derivatives of various spectral ranges were treated by the same statistical approach. Frequencies assigned to stretching and/or bending of CO and CH2 groups (1020–1260 cm−1) produced the best discrimination among samples. Findings are discussed with reference to literature reports about FT-MIR applicability under various oxidation conditions of virgin olive oil (VOO). A systematic inter-laboratory study is suggested in order FT-MIR/ATR to be used as a robust tool in VOO quality control. Practical applications: There is an increasing awareness among consumers and olive oil producers and distributors about virgin olive oil freshness and discussions are on the way for updating of the relevant EU regulations on its quality characteristics. Modernization of methods of analysis and introduction of additional criteria can be achieved by the employment of powerful techniques that can provide solid, multiple type of information with little sample manipulation. FT-MIR/ATR requires no sample preparation, the spectra are related to all chemical components of the lipid matrix and are recorded over a broad region (4000–400 cm−1) in few minutes. Chemometric analysis of the numerous peaks extracts all of the valuable information that can enhance claims or disputes about the oxidative status of a virgin olive oil (e.g., freshness or loss of freshness). Moreover, FT-MIR apparatus has multiple uses in the oil industry (authenticity, origin) so that an investment on such a green technique is advisable.

We report the synthesis of high-quality graphene on Cu foils using hot-filament chemical vapor deposition technique and demonstrate that by suitably varying the CH4 and H2 flow rates, one can also obtain hydrogenated graphene. Micro-Raman spectroscopy studies confirm the growth of monolayer graphene as inferred from the intensity ratio of 2D to G peak which is nearly four in unhydrogenated samples. Detailed Raman area mapping confirms the uniform coverage of monolayer graphene. The grown layer is also transferred onto a Si substrate over ~10 × 10 mm sq. area. The present results provide a leap in synthesis technology of high-quality graphene and pave way for scaling up the process.

The hysteresis effect is a common problem in graphene field-effect transistors (FETs). Usually, the external doping to graphene is considered to be responsible for the hysteresis behavior, but is not yet clearly understood. By monitoring the doping of graphene and the hysteresis in graphene FETs under different atmospheres using in situ Raman spectroscopy, it is confirmed that the electrochemical doping of O(2) /H(2) O redox couple to graphene is responsible for the hysteresis effect. In addition, Raman spectra of graphene on SiO(2) substrate show stronger doping than that suspended, which indicates that SiO(2) substrate plays an important role in the doping of graphene. Herein it is proposed that the doping species (H(2) O and O(2) ) are bounded at the interface of graphene/SiO(2) substrate by hydrogen-bonds with the silanol groups on SiO(2) substrate. The dynamic equilibrium process of the charge-transfer between H(2) O/O(2) redox couple and graphene under electrical field modulation is carefully analyzed using Marcus-Gerischer theory. This work provides a clear view to the mechanism of the hysteresis effect, and is of benefit to a reliable design to suppress the hysteresis in graphene FETs.

Few-layer graphene with average thickness of 3 monolayers has been prepared on 6H-SiC(0001¯) via annealing in argon ambience. The surface structure and morphology are characterized by reflection high-energy electron diffraction, Raman spectroscopy and atomic force microscopy (AFM). Raman mapping measurement reveals that the graphene layer has high uniformity in doping concentration and strains. The SiC surface after graphitization shows steps with height

Here we report the data on the few layer graphene films grown by a chemical vapour deposition on nickel foils and transferred onto desirable substrates for different applications. The experimental conditions have been optimized to prepare a really single graphene layer. A strong influence of the growth conditions onto the number of graphene layers has been revealed. Raman spectroscopy was used to confirm the formation of the single graphene layer with a little amount of defects. To estimate a transmittance of graphene films the optical absorption spectra have been measured. A number of graphene layers in different samples has been estimated on the base of an optical absorbance of a monolayer graphene (2.3% of the incident light intensity). (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The concept of coding metasurface makes a link between physically metamaterial particles and digital codes, and hence it is possible to perform digital signal processing on the coding metasurface to realize unusual physical phenomena. Here, this study presents to perform Fourier operations on coding metasurfaces and proposes a principle called as scattering-pattern shift using the convolution theorem, which allows steering of the scattering pattern to an arbitrarily predesigned direction. Owing to the constant reflection amplitude of coding particles, the required coding pattern can be simply achieved by the modulus of two coding matrices. This study demonstrates that the scattering patterns that are directly calculated from the coding pattern using the Fourier transform have excellent agreements to the numerical simulations based on realistic coding structures, providing an efficient method in optimizing coding patterns to achieve predesigned scattering beams. The most important advantage of this approach over the previous schemes in producing anomalous single-beam scattering is its flexible and continuous controls to arbitrary directions. This work opens a new route to study metamaterial from a fully digital perspective, predicting the possibility of combining conventional theorems in digital signal processing with the coding metasurface to realize more powerful manipulations of electromagnetic waves.

Multilayer structures of graphene oxide-zinc oxide nanorods (GO-ZnONRs) hybrids are successfully grown for use as an active material in resistive switching random access memory (RRAM) devices. A considerable reduction in the OFF current is achieved through a layer-by-layer growth of GO-ZnONR multilayers up to three repeating layers as the active material. The scanning electron microscope images and X-ray diffraction patterns of the hybrid multilayer structures reveal that vertically oriented ZnONRs are sandwiched between GO sheets. A Raman analysis shows that the G peak position in GO redshifts, due to the COZn bonding at interfaces of the hybrid multilayer structures. X-ray photoelectron spectroscopy analysis of the hybrid multilayer structures also confirms the growth of GO on ZnONRs and secondary ZnONRs on GO, through a COZn bonding. This study realizes the growth of vertically oriented secondary and tertiary ZnONRs on GO, accompanying a tuning of photoluminescent emission wavelength. This hybrid multilayer structure-based resistive memory device exhibits a stable resistive switching behavior with an ON–OFF ratio up to 3.3 × 105, which is higher by three orders of magnitude than the ON–OFF ratio of a single-layer ZnONRs based device.

This paper presents a model-based method for clustering multivariate binary observations that incorporates constraints consistent with the scientific context. The approach is motivated by the precision medicine problem of identifying autoimmune disease patient subsets or classes who may require different treatments. We start with a family of restricted latent class models or RLCMs (e.g., Xu and Shang, 2018). However, in the motivating example and many others like it, the unknown number of classes and the definition of classes using binary states are among the targets of inference. We use a Bayesian approach to RCLMs in order to use informative prior assumptions on the number and definitions of latent classes to be consistent with scientific knowledge so that the posterior distribution tends to concentrate on smaller numbers of clusters and sparser binary patterns. The paper derives a posterior sampling algorithm based on Markov chain Monte Carlo with split-merge updates to efficiently explore the space of clustering allocations. Through simulations under the assumed model and realistic deviations from it, we demonstrate greater interpretability of results and superior finite-sample clustering performance for our method compared to common alternatives. The methods are illustrated with an analysis of protein data to detect clusters representing autoantibody classes among scleroderma patients. This article is protected by copyright. All rights reserved.

Ferroelectric materials, and more specifically ferroelectric domain walls (DWs) have become an area of intense research in recent years. Novel physical phenomena have been discovered at these nanoscale topological polarization discontinuities by mapping out the polarization in each atomic unit cell around the DW in a scanning transmission electron microscope (STEM). However, identifying these features requires an understanding of the polarization in the overall domain structure of the TEM sample, which is often a time-consuming process. Here, a fast method of polarization mapping in the TEM is presented, which can be applied to a range of ferroelectric materials. Due to the coupling of polarization to spontaneous strain, we can isolate different strain states and demonstrate the fast mapping of the domain structure in ferroelectric lead titanate (PTO). The method only requires a high-resolution TEM or STEM image and is less sensitive to zone axis or local strain effects, which may affect other techniques. Thus, it is easily applicable to in-situ experiments. The complimentary benefits of Fourier masking with more advanced mapping strategies and its application to other materials are discussed. These results imply that Fourier masked polarization mapping will be a useful tool for electron microscopists in streamlining their analysis of ferroelectric TEM samples. LAY DESCRIPTION: This paper addresses a problem that often occurs when looking at a ferroelectric material in the Transmission Electron Microscope (TEM). Ferroelectric samples are interesting because they form tiny areas inside themselves with arrow of charge in each one. The thinner the sample, the smaller these regions, called "domains" become. These arrows of charge point in different directions in each domain of the sample. The boundary where these domains meet have interesting properties to study in a TEM but it's important to figure out which way the arrows point in the domains around the boundary. What causes the arrows in the different domains is tiny shifts of different atoms in unit cell away from their neutral position, usually because they're being squeezed by pressure from the domains nearby. The problem is that these tiny atoms moving are difficult to measure and see where the charged arrow is pointing, often it's hard to know how many different domains are even in the sample and where they begin. This paper discusses a method called "Fourier masking" to quickly see what's going on in the overall TEM sample, where the domains are and roughly where the arrows point. It does this by looking at the spacings of the atoms from a magnification where you can just about see the lines of atoms. In lead titanate the unit cell is a rectangle and the arrow always points in line with the long side of the rectangle. The Fourier masking lets you see which direction the long side of the rectangular unit cell is pointing in different parts of your TEM image. The big advantage is that it takes about two minutes to do and uses software that almost every TEM already has. That lets the TEM user quickly know where the domains are in their TEM samples and roughly which way the arrows of charge are pointing. Then they can choose the most interesting features focus on for higher resolution analysis.