Non-enzymatic fluorescent glucose sensor using vertically aligned ZnO nanotubes grown by a one-step, seedless hydrothermal method.

A sensitive non-enzymatic fluorescent glucose sensor, consisting of vertically aligned ZnO nanotubes (NTs) grown on low-cost printed circuit board substrates, is described. The ZnO NTs were synthesized by a one-step hydrothermal method without using a seed layer. The sensor function is based on the photoluminescence (PL) quenching of ZnO NTs treated with different concentrations of glucose. The UV emission (emission maximum at 384 nm under 325 nm excitation) decreases linearly with increasing glucose concentration. The sensor exhibits a sensitivity of 3.5%·mM-1 (defined as percentage change of the PL peak intensity per mM) and a lower limit of detection (LOD) of 70 µM. This is better than previously reported work based on the use of ZnO nanostructures. The detection range is 0.1-15 mM which makes the sensor suitable for practical uses in glucose sensing. The sensor was successfully applied to the analysis of human blood serum samples. It is not interfered by common concentrations of ascorbic acid, uric acid, bovine serum albumin, maltose, fructose, and sucrose. Graphical abstract Schematic of the one-step, seedless hydrothermal method utilized for synthesizing vertically aligned ZnO nanotubes on printed circuit board substrates (PCBs). The ZnO nanotubes were used to monitor glucose concentrations in a non-enzymatic fluorescent sensor.

A Cartesian coordinate system for human cerebral cortex.

The most commonly used method for specifying the locations of functional areas in the human cerebral cortex is the coordinate system of Talairach and Tournoux (Co-planar Stereotaxic Altas of The Human Brain (1988) Georg Thieme Verlag, Stuttgart). It was designed to locate subcortical nuclei by reference to an axis joining the anterior and posterior commissures. The coordinate system has difficulties, however, when applied to cortical locations: (1) it can be difficult to locate the posterior commissure (PC); (2) the fundamental axis is short, and errors in specifying the axis lead to large errors at the cortical surface; (3) there is no normalisation for brain size. We sought to rectify these problems with a new coordinate system, the Sydney system, in which the fundamental axis runs in the medial sagittal plane from the anterior edge of the corpus callosum to the posterior end of the parieto-occipital sulcus. Normalisation is achieved by dividing all distances by the length of the fundamental axis. Using functionally important points and anatomical landmarks on cadaveric specimens and magnetic resonance images (MRI), three-dimensional coordinates were measured in both the Talairach and Sydney systems. The Sydney system has the following advantages over the Talairach system: (1) the fundamental axis is more than four times longer and is easier to identify; (2) the Sydney system is more precise, in that it reduces the spread of points across the sample; (3) the normalised coordinates allow locations to be compared across individuals, regardless of brain size. We conclude that for the mapping of cortical areas, the Sydney system is potentially an improvement on Talairach's.

Australian residence and heart disease risk in Vietnamese-born women.

SUMMARY: The aim of this study was to compare the disease risk profile of Vietnamese women who have lived in Australia for 2-15 years with a newly arrived group of Vietnamese women. The design was a comparison of two cross-sectional surveys (n = 256); one newly arrived (n = 159) and one (n = 97) who had lived in Australia for 2-15 years. The main outcome measures were body mass index (BMI), waist to hip ratio (WHR), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and TC/HDL ratio (atherogenic index). The longer-stay residents had similar BMI (21.5 ± 3.5 kg/m(2) vs. 21.1 ± 3.1 kg/m(2), p = 0.2); lower waist (69.3 ± 7.5 cm vs. 71.4 ± 7.6 cm, p = 0.8), WHR (0.76 ± 0.06 vs. 0.80 ± 0.06, p = 0.0001), TC (4.7 ± 1.0 mmol/L vs. 4.9 ± 0.9 mmol/L, p = 0.001), TC/HDL (3.0 ± 2.0 vs. 4.7 ± 2.0, p = 0.006) and higher hip measurement (91.1 ± 7.4 cm vs. 89.1 ± 5.6 cm, p = 0.009) than newly arrived Vietnamese women. After adjustment for BMI and age the odds of having a higher waist and WHR was significantly less for longer-stay residents, while the odds of having larger hips was doubled. The odds of having a high atherogenic index as estimated by the TC/HDL ratio was halved for the longer-stay residents (p = 0.15). We conclude that Vietnamese women we surveyed who have lived in Australia for 2-15 years have the same BMI, but lower levels of abdominal obesity and lower atherogenic index than newly arrived Vietnamese women surveyed.: