Testing the Assumption of Non-differential Misclassification in Case-Control Studies

One of the not yet solved issues regarding the misclassification in case-control studies is whether the misclassification rates are the same for both cases and controls. Currently, a common practice is to assume that the rates are the same, that is, the non-differential misclassification assumption. However, it has been suspected that this assumption may not be valid in practical applications. Unfortunately, no test is available so far to test the validity of the non-differential misclassification assumption. A method is presented to test the validity of non-differential misclassification assumption in case-control studies with 2 × 2 tables when validation data are not available. First, a theory of exposure operating characteristic curve is developed. Next, two non-parametric methods are presented to test the assumption of non-differential misclassification. Three real-data sets taken from practical applications are used as examples to illustrate the methods

Sol–Gel Spin Coating Growth of Magnesium-Doped Indium Nitride Thin Films on Different Substrates

We report on the growth of p-type indium nitride (InN) thin films on different substrates using a relatively simple and cost-effective sol-gel spin coating method. The precursors for the indium source and p-type dopant were indium nitrate hydrate and magnesium chloride 6-hydrate powders, respectively. The structural, morphology, and optical properties of p-type InN thin films grown on different substrates were investigated. X-ray diffraction patterns revealed that the deposited Mg-doped InN thin film on GaN/AlN/Si(111) template show polycrystalline wurtzite structure with a strong InN(002) orientation and have a good crystallinity. Field emission scanning electron microscopy images and energy dispersive X-ray results showed that all the films exhibit densely packed surface morphology with hexagonal-like grains shape and low oxygen percentage with almost 1:1 ratio of indium to nitrogen. Moreover, two Raman-active modes of E2(High) and A1(LO) of the wurtzite InN were clearly observed for all samples. The ultraviolet-visible-near infrared spectroscopy results showed that the energy bandgap of the Mg-doped InN thin films was in the range of 1.62-1.66 eV. From all the results, it can be concluded that the Mg doped InN film on GaN/AlN/Si(111) substrate has better crystalline quality as compared to that of other substrates

Hierarchical ultrathin NiAl layered double hydroxide nanosheet arrays on carbon nanotube paper as advanced hybrid electrode for high performance hybrid capacitors

To effectively improve the power density and rate capability of layered double hydroxide (LDH) based supercapacitors, a hybrid supercapacitor (HSC) comprising of hierarchical ultrathin NiAl-LDH nanosheet arrays on carbon nanotube paper (CNP-LDH) is developed with porous graphene nanosheets as the negative electrode for the first time. SEM image shows that hierarchical NiAl LDH nanosheet arrays are assembled by numerous ultrathin nanosheets with thickness of a few to tens of nanometers. Remarkably, with an operating voltage of 1.6 V, the HSC possesses a high energy density of 50.0 Wh kg-1 at an average power density of 467 W kg-1. Even at a fast discharging time of 3.9 s, a high energy density (23.3 Wh kg-1) could also be retained at a power density of 21.5 kW kg-1. Moreover, the HSC exhibits cycling stability with a retention rate of 78% after 5000-cycle charge-discharge test at 5 A g-1. The results inspire us to propose our high-performance CNP-LDH as a promising electrode for energy storage applications

Nickel hydroxide/chemical vapor deposition-grown graphene/nickel hydroxide/nickel foam hybrid electrode for high performance supercapacitors

Rational design of electrode structures has been recognized as an effective strategy to improve the electrochemical performance of electrode materials. Herein, we demonstrate an integrated electrode in which nickel hydroxide (Ni(OH)2) nanosheets are deposited on both sides of chemical vapor deposition-grown graphene on Ni foam, which not only effectively optimizes electrical conductivity of Ni(OH)2, but also accommodates the structural deformation assciated with the large volume change upon cycling. The synthesized Ni(OH)2/graphene/Ni(OH)2/Ni foam electrode exhibits a high specific capacity of 991 C g−1 at a current density of 1 A g−1, which is higher than the theoretical specific capacity of additive sum of Ni(OH)2 and graphene, and retains 95.4% of the initial capacity after 5000 cycles. A hybrid supercapacitor is constructed by using Ni(OH)2/graphene/Ni(OH)2/Ni foam as the positive electrode and activated carbon on Ni foam as the negative electrode, which achieves a maximum energy density of 49.5 W h kg−1 at a power density of 750 W kg−1, and excellent cycling lifespans with 89.3% retention after 10000 cycles at 10 A g−1

Influences of Thermal stability of Doped Indium Nitride Thin Films at Elevated Temperatures by Sol-Gel spin Coating Method

In this study, doped indium nitride (InN:Mg) thin films grown on silicon ( Ill) substrate are prepared via so l-gel spin coating method followed by nitridation process. The degree of nitrid at ion of ln 20 3 to InN was very sensitive to the nitridat ion temperature. A custo-made tube furnace was used to do nitridation process which can resolve the low dissociation temperature issue of lnN:Mg. In this research, attention was focused on the influences of nitridation temperatures on the structural of the synthesized lnN:Mg thin films. The films were nitridated at range 580-620 °C for 45 min and the growth of lnN:Mg thin films were investigated. X-ray diffraction (XRD) results revealed that the deposited lnN:Mg thin film at 600°C has InN( I 00), lnN(002) and InN( I 0 I) preferred orientation. Field emission scanning electron microscopy (FESEM) showed th e surface of the films exhibited densely packed grains. Lastly, the elemental composition the deposited thin films was analysed by using energy dispersive Xrays spectroscopy (EDX). The detected atomic percentages at nitridation temperature 600°C revealed the lowest oxygen percentage with almost ratio. indium to nitrogen. Moreover. the atom ic percentage of oxygen increases with increasing nitridation temperatue. Finally, all the results revealed that 600°C of nitridation temperature was the most efficient temperature for the nitridation process. All the measurements were performed at room temperature

Structural and luminescent diversities of Eu3+ activated Gd2O3 nanophosphors

In this work we investigated both structural and optical characteristic of erbium doped ternary TeO2-TiO2-Bi2O3 tellurite oxide based glasses, synthesized via melt-quench method. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed its glassy nature and stability. Raman analysis revealed the presence of various coordination state TeO2 network consisting stretching/bending vibrations of Te-O bonds in the [TeO4] trigonal bi-pyramid units and fraction of [TeO3, TeO3+1] trigonal pyramids. From optical absorption measurement both optical band gap and Judd-Ofelt analysis (intensity parameters Ωt (t=2, 4, 6), transition probabilities, and radiative lifetimes of the Er3+ ions) have been performed for both host and doped glasses respectively. Photoluminescence studies for upconversion and near-infrared emissions analysis (under 980 nm excitation at room temperature. Both optical transition mechanism which involved nonradiative energy transfer between Er3+ ions through cross-relaxation and energy migration were also explained in detailed

Qualitative Resistance of Sarawak Rice Landraces Against Pyricularia oryzae

Malaysia rice production is threatened by rice blast disease, caused by Pyricularia oryzae. Yield can be greatly reduced by this disease as it can attack all the aerial parts of rice including leaves, node, neck, and collar. The use of resistant cultivar, which can be produced from resistance breeding, can control the disease effectively. Sarawak, in Malaysian Borneo, has diverse rice landraces, which can be genetic resources for resistance breeding. Study on the resistance of Sarawak rice landraces against P. oryzae, is still limited. In this study, diseased leaf samples were collected from rice fields in Serian division, Sarawak. One isolate was successfully obtained and designated as B2PG. The morphological characteristics were documented. Six Sarawak rice landraces were challenged with isolate B2PG. Four of the rice landraces were resistant and might carry resistance gene(s), which can be utilised in future breeding program

Isolation and characterization of Pyricularia oryzae isolated from lowland rice in Sarawak, Malaysian Borneo

Aims: Rice blast disease caused by Pyricularia oryzae is one of the major biotic diseases of rice in Sarawak, Malaysian Borneo. This study aims to isolate and characterize rice blast fungus obtained from infected leaf collected from four different divisions in Sarawak, viz, Miri, Serian, Sri Aman, and Kuching. Methodology and results: Twelve succeeded isolates were pre-identified as P. oryzae by morphological characteristics of spores, followed by verification through (internal transcribed spacer) ITS sequencing. The isolates were evaluated for morphological characteristics, growth rate and sporulation rate, which were grown on two types of media, (filtered oatmeal agar) FOMA and (potato dextrose agar) PDA. Morphological characterization showed that the colony surface of the different isolates varied from smooth and fluffy to rough and flattened mycelia; some were with the present of concentric rings, and some with aerial mycelia. The growth rate and sporulation rate of each isolate varied based on types of media used. Most of the isolates grew faster on PDA than on FOMA but produced higher number of spores on FOMA as compared to PDA. Conclusion, significance and impact of study: This preliminary study showed that there were variations observed based on morphological and physiological characterization for the different isolates collected in Sarawak, Malaysian Borneo. This study is the first step towards understanding variation in the population of P. oryzae from Sarawak

2.45GHz radiofrequency fields alter gene expression in cultured human cells

AbstractThe biological effect of radiofrequency (RF) fields remains controversial. We address this issue by examining whether RF fields can cause changes in gene expression. We used the pulsed RF fields at a frequency of 2.45GHz that is commonly used in telecommunication to expose cultured human HL-60 cells. We used the serial analysis of gene expression (SAGE) method to measure the RF effect on gene expression at the genome level. We observed that 221 genes altered their expression after a 2-h exposure. The number of affected genes increased to 759 after a 6-h exposure. Functional classification of the affected genes reveals that apoptosis-related genes were among the upregulated ones and the cell cycle genes among the downregulated ones. We observed no significant increase in the expression of heat shock genes. These results indicate that the RF fields at 2.45GHz can alter gene expression in cultured human cells through non-thermal mechanism

Observation of whispering gallery modes in InGaN/GaN multi-quantum well microdisks with Ag plasmonic nanoparticles on Si pedestals

In this study, plasmonic freestanding InGaN/GaN multi-quantum well (MQW) microdisks were fabricated on Si (111) pedestals using wet chemical undercut etching, followed by decorating of Ag nanoparticles on microdisks to improve whispering gallery mode (WGM) resonance emission. The enhancement resulted from the plasmonic coupling effect between excitons in MQWs and localized surface plasmons of Ag. The radial resonance of WGMs from optically pumped microdisk cavities were observed in the photoluminescence spectra at a threshold optical pumping power density of 4.7 kW/cm2 with a WGM mode spacing of Δλ = 1.3 nm