Age at menopause has been found to be associated positively with bone mineral density, and age at menarche has been found to be associated negatively with bone mineral density. However, there have been few studies on the relations of timing of menopause and length of the reproductive period with bone mineral density. The purpose of this study was to examine the relations of timing of menopause ...

1. The influence of pregnancy, lactation and weaning on bone mineral density in healthy women was investigated during a 2 year prospective study of 59 pregnant and lactating women from the 18th week of gestation. 2. Bone mineral density was measured by dual energy X-ray absorptiometry at the non-dominant radius ultra distally and more proximally in the 18th and 37th weeks of gestation, and 0, 3...

Bone is a strong and tough material composed of apatite mineral, organic matter, and water. Changes in composition and organization of these building blocks affect bone's mechanical integrity. Skeletal disorders often affect bone's mineral phase, either by variations in the collagen or directly altering mineralization. The aim of the current study was to explore the differences in the mineral o...

Homogeneity of the primary layer in mineral wool production process is required for high quality products. State-of-the-art measurement techniques for the evaluation of primary layer homogeneity are very slow and can only be applied after the product is manufactured. We present here a method that enables on-line monitoring and control and is based on experimental modeling using neural networks....

introduction: the aim of this study was to compare the chemical compounds of white proroot mineral trioxide aggregate (wmta) hydrated at different ph environments. methods and materials: mixed samples of wmta were kept in acidic (ph=5.4), neutral (ph=7.4) and alkaline (ph=9.4) environments for 48 h. then, x-ray diffraction (xrd) analysis was performed for both hydrated and powder forms of wmta....

objectives: maintaining pulp vitality is a main goal in restorative dentistry. introduction of pulp capping agents paved the way to eliminate the shortcomings of these materials and obtain successful restorations. on the other hand, nanotechnology is an emerging field of science with increasing use in dental materials. this study sought to assess the effect of addition of nano-tio2, nano-sio2 a...

osteoporosis is a silent epidemy of today's world, and is also a prevalent problem of health in iran. the role of nutrients such as ascorbic acid, a key antioxidant vitamin, in this disease has recently attracted researchers' attention. in this study, we studied the relation between plasma ascorbic acid concentration and bone mineral density (bmd) in women referring to jami clinic, te...

background and aims. substituting chlorhexidine (chx) for water has been shown to enhance antimicrobial activity of mineral trioxide aggregate (mta). the purpose of this study was to compare the compressive strength of mta mixed with distilled water, 0.12% and 0.2% chlorhexidine. materials and methods. mta was mixed according to manufacturer’s instructions in group i (n = 20). in groups ii & ii...

objective: in a cavity prepared through endodontic surgery, application of a material to provide apical seal and prevent bacterial and tissue exudates is of great importance. the purpose of this study was to compare the sealing ability of biocalex with white mta, gray mta, and amalgam as root-end fillings. materials and methods: sixty-six single-rooted extracted human teeth were cleaned, shaped...

dry land salinity is one of the major problems affecting agricultural products. the main consequences of plant exposure to salt stress are water deficit and ion excess, which lead to several morphological and physiological changes. in order to evaluate the effect of salinity on some physiological characteristics of 8 spring rapeseed cultivars, an experiment was conducted in the greenhouse at ya...