Hair graying is the most obvious sign of aging in humans, yet its mechanism is largely unknown. Here, we used melanocyte-tagged transgenic mice and aging human hair follicles to demonstrate that hair graying is caused by defective self-maintenance of melanocyte stem cells. This process is accelerated dramatically with Bcl2 deficiency, which causes selective apoptosis of melanocyte stem cells, b...

Methods of rapidly and accurately assessing the chemical stability of pharmaceutical dosage forms are reviewed with respect to the major degradation mechanisms generally observed in pharmaceutical development. Methods are discussed, with the appropriate caveats, for accelerated aging of liquid and solid dosage forms, including small and large molecule active pharmaceutical ingredients. In parti...

A, Sartori J, et al. Telomere length, oxidative stress, inflammation and BDNF levels in siblings of patients with bipolar disorder: implications for accelerated cellular aging. Int J Neuropsychopharmacol. 2017;20:445-54. 5 Czepielewski LS, Massuda R, Panizzutti B, da Rosa ED, de Lucena D, Macêdo D, et al. Telomere length in subjects with schizophrenia, their unaffected siblings and healthy cont...

Refining the grain size of γ-TiAl alloys to improve their strength and ductility is academic interest. Thus, we report a multi-stage heat treatment method consisting solution treatment, cyclic annealing, short aging refine microstructure Ti–48Al–2Cr–2Nb alloy. The solution-treated was refined from 1100 191 μm by promoting feathery γ packets. Fine duplex grains below 23 were obtained through dis...

The ASTM D 1037 six-cycle accelerated-aging test for wood-based panel products was analyzed to determine how each successive aging cycle and selected steps in each cycle contribute to panel deterioration. Hardboard, particleboard, flakeboard, waferboard, and oriented strandboard were evaluated. The rate of panel deterioration generally decreased with each successive aging cycle. Four cycles of ...

Purpose: The purpose of the current study was to examine the effect of accelerated aging on color stability of the In-Ceram and Cergogold ceramic materials. Materials and Methods: Ceramic samples with 1.0 mm in diameter and 1.5 mm in thickness were prepared in three commonly used shades. CIE Lab readings were recorded with a spectrophotometer prior to experiments and after 100-hour accelerated ...

UNLABELLED Esthetics and durability of materials used to fabricate artificial eyes has been an important issue since artificial eyes are essential to restore esthetics and function, protect the remaining tissues and help with patients' psychological therapy. However, these materials are submitted to degrading effects of environmental agents on the physical properties of the acrylic resin. OBJ...

Composite resins were reinforced with glass and polyethylene fibers in this study, and the effect of fiber reinforcement on the color change of composite resins was investigated. After accelerated aging, the effect of fiber reinforcement on the color stability of composite resins was also examined. There were three experimental groups (n=12 disks per group): non-fiber-reinforced composite (non-...

Epigenetic alterations during aging have been proposed to contribute to decline in physical and cognitive functions, and accelerated epigenetic aging has been associated with disease and all-cause mortality later in life. In this study, we estimated epigenetic age dynamics in groups with different memory trajectories (maintained high performance, average decline, and accelerated decline) over a...

17–4 PH (precipitation hardening) stainless steel is commonly used for the fabrication of complicated molds with conformal cooling channels using laser powder bed fusion process ( L -PBF). However, their microstructure in as-printed condition varies notably chemical composition feedstock powder, resulting different age-hardening behavior. In present investigation, components were fabricated by ...