20 research outputs found
Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c
Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose
diabetes, but may identify different people as having diabetes. We used data from 117
population-based studies and quantified, in different world regions, the prevalence of
diagnosed diabetes, and whether those who were previously undiagnosed and detected
as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed
prediction equations for estimating the probability that a person without previously
diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa.
The age-standardised proportion of diabetes that was previously undiagnosed, and
detected in survey screening, ranged from 30% in the high-income western region to 66%
in south Asia. Among those with screen-detected diabetes with either test, the agestandardised
proportion who had elevated levels of both FPG and HbA1c was 29-39%
across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and
middle-income regions, isolated elevated HbA1c more common than isolated elevated
FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and
underestimate diabetes prevalence. Our prediction equations help allocate finite
resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and
surveillance.peer-reviewe
Synthesis and characterization of magnanese ferrite nanoparticles by thermal treatment method.
Cubic structured manganese ferrite nanoparticles were synthesized by a thermal treatment method followed by calcination at various temperatures from 723 to 873 K. In this investigation, we used polyvinyl pyrrolidon (PVP) as a capping agent to control the agglomeration of the nanoparticles. The characterization studies were conducted by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The average particle sizes of manganese ferrite nanoparticles were determined by TEM, which increased with the calcination temperature from 12 to 22 nm and they had good agreement with XRD results. Fourier transform infrared spectroscopy confirmed the presence of metal oxide bands at all temperatures and the absence of organic bands at 873 K. Magnetic properties were demonstrated by a vibrating sample magnetometer, which showed a super-paramagnetic behavior for all samples and also saturation magnetization (Ms) increases from 3.06 to 15.78 emu/g by increasing the calcination temperature. The magnetic properties were also confirmed by the use of electron paramagnetic resonance spectroscopy, which revealed the existence of unpaired electrons and also measured peak-to-peak line width, resonant magnetic field and the g-factor
Synthesis and characterization of ZnO flower-like multisheets grown on metal buffer layer
ZnO flower-like multisheets were synthesized on Si (1 1 1) and corning glass substrates with Cu and
Au-Cu alloy buffer layers via vapor phase transport (VPT) method. The structures and morphologies
of the products were investigated using X-ray diffraction (XRD) and field emission scanning electron
microscopy (FESEM). The flowers have several parallel petal-like nanosheets that are perpendicular to
the main axis. The metal buffer layer affects the growth rates and initial nucleation of ZnO structures,
resulting in different numbers and shapes of petals. The optical properties were studied with
photoluminescence (PL) and Raman spectroscopy. The intensity of the visible emission peak for Cu
coated silicon was the lowest, which may indicate that the surface of defects being covered with Cu
atoms. The presence of the E1(LO) and A1(LO) phonon peaks in the Raman spectra reveal the status of
c-axis and the surface of the samples. In addition, the growth mechanism of the ZnO flower-like
multisheet structure was investigated based on the FESEM images for different growth times