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Biomedical subjects

Joshua A Tournas

Publications and source records attributed to Joshua A Tournas.

4 recordsLinked to original sources

Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin.

Ferulic acid is a potent ubiquitous plant antioxidant. Its incorporation into a topical solution of 15%l-ascorbic acid and 1%alpha-tocopherol improved chemical stability of the vitamins (C+E) and doubled photoprotection to solar-simulated irradiation of skin from 4-fold to approximately 8-fold as measured by both erythema and sunburn cell formation. Inhibition of apoptosis was associated with reduced induction of caspase-3 and caspase-7. This antioxidant formulation efficiently reduced thymine dimer formation. This combination of pure natural low molecular weight antioxidants provides meaningful synergistic protection against oxidative stress in skin and should be useful for protection against photoaging and skin cancer.

Animals↗

Creating multiple time-shared laser traps with simultaneous displacement detection using digital signal processing hardware.

We present a design for implementing multiple laser traps for single-molecule studies through time-sharing using commercially available digital signal processing hardware in a computer running a standard multitasking operating system. This design enables four to six independent laser traps with a visitation frequency of 10,000s(-1)trap(-1) and a timing jitter of +/-0.5 micros to be created. The design also achieves nanometer-resolution detection of displacement in all of the traps simultaneously via back focal-plane interferometry and only a single quadrant photodiode detector. Practical design considerations and limitations together with the use of fiberlasers in laser traps are discussed. Using this device, the mechanokinetics of multiple molecular motors or adhesion proteins may be measured simultaneously. We present the example biological application of two kinesin-coated beads in separate traps moving on different portions of a microtubule.

Equipment Design↗

Laser and novel light source treatments for psoriasis.

BACKGROUND AND OBJECTIVES: There are many treatment modalities for psoriasis including topical therapy, ultraviolet light therapy, systemic agents, and more recently the advent of the biologic agents. STUDY DESIGN/MATERIALS AND METHODS: In addition, selective treatment using lasers and light sources that target the individual psoriatic plaques have also been employed. RESULTS/CONCLUSION: This article will highlight and review the employment of laser-assisted devices in the treatment of plaque psoriasis.

Humans↗