Mineral oils (also known as base oils, mineral base oils or lubricant base oils) are chemical substances prepared from naturally occurring crude petroleum oil. Crude oil is distilled first at atmospheric pressure and then under high vacuum to yield vacuum distillates and residual fractions that can be further refined to mineral oils. Mineral oils refined from petroleum crude oils are complex an...

Solid and aqueous phase Al species are recognized to affect organic matter (OM) stabilization in forest soils. However, little is known about the dynamics of formation, composition and dissolution of organo-Al hydroxide complexes in microbiallyactive soil systems, where plant litter is subject to microbial decomposition in close proximity to mineral weathering reactions. We incubated gibbsite–q...

The pediatric origin of osteoporosis has led many investigators to focus on determining factors that influence bone gain during growth and methods for optimizing this gain. Bone responds to bone loading activities by increasing mass or size. Overall, pediatric studies have found a positive effect of bone loading on bone size and accrual, but the types of loads necessary for a bone response have...

Application of effective remedies of fight against salt sedimentation gives the chance of creation of the reverse, closed and drainless systems conforming to requirements of modern production and ecology. Salt sedimentation inhibitors at an additive to water from 2,0 to 10 g/m3 for 90% and more prevent scaling on a surface of heatexchange devices, boilers, pipelines, etc. For the purpose of dev...

Objective. Analysis of bone mineral density (BMD) in the elderly and its associated factors according to sex. Methods. A cross-sectional study is presented herein, with a random sample of 132 noninstitutionalized elderly people. Individuals who did not use diuretics were excluded. BMD was obtained from examination of total body densitometry and its association with sociodemographic variables, l...

To the Editor: In their report on the effects of dehydroepiandrosterone (DHEA) and testosterone when used as antiaging supplements, Nair et al. (Oct. 19 issue)1 conclude that low-dose testosterone replacement in elderly men has no “physiologically relevant beneficial effects on body composition, physical performance, [or] insulin sensitivity.” However, this conclusion is premature, since the te...

Pathomechanisms underlying vascular calcification biogenesis are still incompletely understood. Biomineral from human atherosclerotic intimal plaques; human, equine, and bovine medial vascular calcifications; and human and equine bone was released from collagenous organic matrix by sodium hydroxide/sodium hypochlorite digestion. Solid-state (13)C NMR of intimal plaque mineral shows signals from...

OBJECTIVE To investigate the relationship between total and segmental body fat, bone mineral density and bone mineral content in undergraduate students stratified according to nutritional status. METHODS The study included 45 male undergraduate students aged between 20 and 30 years. Total and segmental body composition, bone mineral density and bone mineral content assessments were performed ...

Mining in its broadest sense is the process of obtaining useful minerals from the earth’s crust. A mineral is generally defined as any natural accruing substance of definite chemical composition and consistent physical properties. An ore is a mineral or combination of minerals from which a useful substance, such gold, can be extracted and marketed at a price that will recover the costs of minin...