Experimental and theoretical approach on the optical properties of zinc borotellurite glass doped with dysprosium oxide.

A series of glass samples with chemical formula {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1-x(Dy2O3)x where x=0.01, 0.02, 0.03, 0.04 and 0.05M fraction were synthesized through conventional melt-quenching method. The most common way to fabricate a glass material is by fusion of two or more component oxides followed by their quenching. This technique is known as melt-quenching technique. Kaur et al. (2016) [1] highlighted that the melt-quenching method able to enhance the mechanical properties like hardness and flexural strength of the material. The nature of the glass systems is proven to be amorphous based on the XRD pattern. The FTIR spectra of the glass systems confirm the existence of five bands which are assigned for the BO4, BO3, TeO4 and TeO3 vibrational groups. The density of the glass systems is increased with the addition of Dy2O3 while the molar volume is found to be inversely proportional to the density of the proposed glass. The optical properties of the glasses are determined through the absorption spectra obtained from the UV-VIS spectrophotometer. From the absorption spectra, the indirect and direct optical band gaps and the Urbach energy are found to be inversely proportional to each other. As the molar fraction of the Dy2O3 increased, the optical band gaps are observed to increase as opposed to the Urbach energy. For this glass system, the values of refractive index, electronic polarizability, oxide ion polarizability and the optical basicity are found to decrease as the addition of the dysprosium oxide is increased. From the emission spectra, two intense blue and yellow emission bands are observed, which correspond to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ ions respectively. The CIE chromaticity coordinates of the zinc borotellurite glass systems are found to be located in the white light region.

Gestational diabetes mellitus: The prevalence, associated factors and foeto-maternal outcome of women attending antenatal care.

OBJECTIVE: The aim of the study is to determine the prevalence of gestational diabetes mellitus (GDM), its associated risk factors, foeto-maternal outcomes and prevalence of postnatal diabetes mellitus (DM). METHODS: This is a cross-sectional study using retrospective data from existing antenatal records of new antenatal women who registered at 72 public health clinics in Selangor in January 2014. RESULTS: A total of 745 antenatal records were reviewed. The prevalence of GDM women was 27.9% (n = 184). GDM risks were higher in women aged 35 years old and above and in those with maternal obesity. GDM women had a higher risk of having a non-spontaneous vaginal delivery compared to non-GDM women. The prevalence of postnatal DM among GDM mother was 12.1%. Working GDM mothers were at higher risk of developing postnatal DM. CONCLUSION: The prevalence of GDM among newly registered women attending antenatal public health care in Selangor was higher than previous studies. Health care personnel need to be vigilant in screening women with risk factors.