Utumma Maghanemi

Bone mineral density at distal forearm in men over 40 years of age in Mae Chaem district, Chiang Mai Province, Thailand: a pilot study

Abstract Objective: To study the prevalence of bone mineral density (BMD) and osteoporosis in the distal forearm among Thai men over 40 years of age in Mae Chaem District, Chiang Mai Province, Thailand. Methods: The subjects in this study were 194 Thai men, aged between 40 and 87 years who resided in Mae Chaem District, Chiang Mai Province, Thailand. Self-administered questionnaires were used for receiving the demographic characteristics information. BMD was measured by peripheral dual energy X-ray absorptiometry at the nondominant distal forearm in all men. Results: The BMD was highest in the age-group 40–49 years and lowest in the age-group 70–87 years. The average T-score at the distal forearm was also highest in the age-group 40–49 years and lowest in the age-group 70–87 years. The BMD decreased as a function of age-group (p < .05). In contrast, the BMD increased as a function of weight (p < .05). Height had weak impact on the BMD in the distal forearm (p > .05). The percentage of osteopenia and osteoporosis are increased as a function of age-group in, while decreased in that of normal bone density. Conclusions: We found the prevalence of osteoporosis in men who resided in Mae Chaem District, Chiang Mai Province, Thailand.

Optical and Luminescence Properties of Pr3+ in Gd2O3-CaO-SiO2-B2O3 Glasses

This paper reports on the results concerning optical absorption and luminescence properties of 25Gd2O3-10CaO-10SiO2-(55-x) B2O3-xPr2O3 (where x is 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) have been synthesized by melting and quenching process. The locations of the absorption peak observed are investigated for the first time. It is shown that the f-f transitions in the studied glasses are allowed by distortions of Pr3+ ions. Seven absorption bands corresponding to the 3H4 → 3P2, 1I6+3P1, 1D2, 1G4, 3F4, 3F3 and 3F2, respectively absorption bands peaked at 459,483,575,1011,1418,1513 and 1931 nm. The luminescence intensity of Pr3+ doped glass under excited at 459 and 483 nm, the emission band under excited at 459 nm wavelengths emission centered at 542 nm (3P0→3H5), 602 nm (1D2→3H4), 646 nm (3P0→3F2) and 689 nm (1D2→3H5) .The emission bands with 483 nm excitation wavelength, the emission band centered at 532 nm (3P1→3H5), 602 nm (1D2→3H4), 646 nm (3P0→3F2) and 725 nm (3P0→3F4), respectively. The present paper brings out the results pertaining to the studies carried out on different structural and optical absorption in UV-VIS-NIR region are also measured and discussed in term of energy levels, energy band gap and emission spectra of Pr3+ ions doped in Gd2O3-CaO-SiO2-B2O3 glasses.

NIR and Upconversion Luminescence Properties of Nd3+ Doped in Gd2O3-CaO-SiO2-B2O3 Glass System

In this work, properties of Nd3+ in Gd2O3-CaO-SiO2-B2O3 glass systems with composition 25Gd2O3-10CaO-10SiO2-(55-x)B2O3-xNd2O3 where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol% were investigated. The optical absorption spectra show peaks at 4F3/2 (877 nm) , 4F5/2+2H9/2 (802 nm), 4F7/2+4S3/2 (743 nm), 4F9/2 (682 nm), 2H11/2 (627 nm), 2G7/2 +4G5/2 (582 nm), 4G7/2 +2K13/2 (527 nm), 4G11/2 (481 nm), 2P1/2 (427 nm) and 2L15/2 + 4D1/2 + 1I11/2+ 4D5/2+ 4D3/2 (355 nm) reflecting the Nd3+ ions in glass matrices. The densities were increased with increasing of Nd2O3 concentration. This indicates the increase of the molecular weight by the replacement of B2O3 with a heavier Nd2O3 oxide in the glass. The upconversion luminescence spectra show bands at 393 nm for all Nd2O3 concentration and the strongest intensity from 2.5 % mol of Nd2O3 was obtained. For NIR luminescence, the intensity of Nd3+ emission spectra increases with increasing concentrations of Nd3+ up to 1.5 mol% and beyond 1.5 mol% the concentration quenching is observed.

Upconversion Luminescence Study of Er3+ in Gadolinium-Calcium- Silicoborate Glasses

The new glass series were prepared in compositions 25Gd2O3-10CaO-10SiO2-(55-x) B2O3-xEr2O3 (where x is 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) by normal melt-quenching technique at the melting temperature of 1,400 °C. The optical spectra were measured and shown absorption bands were assigned to appropriate f-f electronic transitions of Er3+ ions from the 4I15/2 ground state to the following excited states: 4G11/2, 2H9/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I9/2 and 4I11/2. Single peak from upconversion luminescence was observed at 531 nm (green) is assigned to the 2H11/24I15/2. In this work, the strongest peak at 2.0 % mol of Er2O3 was observed. In this work, suggests that the Er3+ ion in gadolinium calcium silicoborate glasses possibly considered as a potential candidate for applications in upconversion-based optical devices.