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A targeted worksite intervention program may be an effective way to lower BP and promote exercise and weight loss.

Abstract.Background and Objectives: The success of permanent laser hair removal suggests that selective photothermolysis (SP) of sebaceous glands, another part of hair follicles, may also have merit. About 30% of sebum consists of fats with copious CH 2 bond content. SP was studied in vitro, using free electron laser (FEL) pulses at an infrared CH 2 vibrational absorption wavelength band.Methods: Absorption spectra of natural and artificially prepared sebum were measured from 200 nm to 3000 nm, to determine wavelengths potentially able to target sebaceous glands. The Jefferson National Accelerator superconducting FEL was used to measure photothermal excitation of aqueous gels, artificial sebum, pig skin, human scalp and forehead skin (sebaceous sites). In vitro skin samples were exposed to FEL pulses from 1620 to 1720 nm, spot diameter 7-9.5 mm with exposure through a cold 4 o C sapphire window in contact with the skin. Exposed and control tissue samples were stained using H&E, and nitroblue tetrazolium chloride staining (NBTC) was used to detect thermal denaturation.Results: Natural and artificial sebum both had absorption peaks near 1210, 1728, 1760, 2306 and 2346 nm. Laser-induced heating of artificial sebum was approximately twice that of water at 1710 and 1720 nm, and about 1.5x higher in human sebaceous glands than in water. Thermal camera imaging showed transient focal heating near sebaceous hair follicles. Histologically, skin samples exposed to ~1700 nm, ~100-125 ms pulses showed evidence of selective thermal damage to sebaceous glands. Sebaceous glands were positive for NBTC staining, without evidence of selective loss in samples exposed to the laser. Epidermis was undamaged in all samples.

We describe a procedure for the simulation of free-electron-laser (FEL) oscillators. The simulation uses a combination of the MEDUSA simulation code for the FEL interaction and the OPC code to model the resonator. The simulations are compared with recent observations of the oscillator at the Thomas Jefferson National Accelerator Facility and are in substantial agreement with the experiment.

Picosecond-infrared-excitation experiments on acetanilide, an a-helix protein analog, indicate that the anomalous 1650-cm _1 band which appears on cooling of acetanilide crystals persists for at least several microseconds following rapid pulsed heating. The ground-state recovery time is 15 ± 5 ps, consistent with a conventional mode strongly coupled to the phonon bath. We therefore suggest that the unusual temperature-dependent spectroscopy of acetanilide can be accounted for by slightly nondegenerate hydrogen-atom configurations in the crystal.