Prediction of clinical non-spine fractures in older black and white men and women with volumetric BMD of the spine and areal BMD of the hip: The health, aging, and body composition study

In a prospective study of 1446 black and white adults 70-79 yr of age (average follow-up, 6.4 yr), vertebral TrvBMD from QCT predicted non-spine fracture in black and white women and black men, but it was not a stronger predictor than total hip aBMD from DXA. Hip aBMD predicted non-spine fracture in black men. Introduction: Areal BMD (aBMD) at multiple skeletal sites predicts clinical non-spine fractures in white and black women and white men. The predictive ability of vertebral trabecular volumetric BMD (TrvBMD) for all types of clinical non-spine fractures has never been tested or compared with hip aBMD. Also, the predictive accuracy of hip aBMD has never been tested prospectively for black men. Materials and Methods: We measured vertebral TrvBMD with QCT and hip aBMD with DXA in 1446 elderly black and white adults (70-79 yr) in the Health, Aging, and Body Composition Study. One hundred fifty-two clinical non-spine fractures were confirmed during an average of 6.4 yr of >95% complete follow-up. We used Cox proportional hazards regression to determine the hazard ratio (HR) and 95% CIs of non-spine fracture per SD reduction in hip aBMD and vertebral TrvBMD. Results: Vertebral TrvBMD and hip aBMD were both associated with risk of non-spine fracture in black and white women and black men. The age-adjusted HR of fracture per SD decrease in BMD was highest in black men (hip aBMD: HR = 2.04, 95 % CI = 1.03, 4.04; vertebral TrvBM D: HR = 3.00, 95 % CI 1.29, 7.00) and lowest in white men (hip aBMD: HR = 1.23, 95 % CI = 0.85, 1.78; vertebral TrvBMD: HR 1.06, 95 % CI = 0.73, 1.54). Adjusted for age, sex, and race, each SD decrease in hip aBMD was associated with a 1.67-fold (95% CI = 1.36. 2.07) greater risk of fracture, and each SD decrease in vertebral TrvBMD was associated with a 1.47-fold (95% CI = 1.18,1.82) greater risk. Combining measurements of hip aBMD and vertebral TrvBMD did not improve fracture prediction. Conclusions: Low BMD measured by either spine QCT or hip DXA predicts non-spine fracture in older black and white women and black men. Vertebral TrvBMD is not a stronger predictor than hip aBMD of non-spine fracture

Formation mechanism of anthracene dimers and excimers in NaY zeolitic nanocavities

The dimer and the excimer formation mechanisms of anthracene in NaY zeolitic nanocavities have been studied by using various spectroscopic techniques of 129Xe NMR, diffuse reflectance, and emission as well as time-resolved fluorescence. Two anthracene molecules adsorb concertedly into a zeolitic supercage to form a ground-state stable dimer. An excited monomer in a singly occupied supercage gives birth to an excimer if another monomer exists in a tetrahedrally connected nearest supercage. An excited monomer forms a nonluminescent ion pair with a monomer in a nearest supercage by transferring an electron within 100 ps. The dark intermediate rearranges to transform into an excimer on the time scale of 400 ps.close161

Supragingival cleaning 3 times a week. The microbiological effects in moderately deep pockets

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