Thulium-doped yttria planar waveguide laser grown by pulsed laser deposition

Lasers operating in the 2 micron wavelength region are of particular interest for various applications in remote sensing/LIDAR, materials processing, and medical treatments. Thulium-doped media have several attractive features for generating light in this wavelength band, including a broad emission bandwidth, long-lived metastable states, absorption bands matched to high-power 0.8 mm diode-pump sources coupled with the potential for high quantum-efficiency due to a 2-for-1 cross-relaxation process. The sesquioxide crystal family is of considerable interest as a potential host due to their excellent thermo-optic characteristics and spectroscopic properties. A key challenge for this host material is its high-temperature growth requirements (some in excess of 2500 K for bulk crystals); as such there has been limited success in fabricating these crystals commercially. Here we report the first growth and lasing results (to the best of our knowledge) of a crystalline Tm:Y2O3 waveguide, fabricated via pulsed laser deposition (PLD)

Caloric restriction in older adults-differential effects of weight loss and reduced weight on brain structure and function

Dietary modifications such as caloric restriction (CR) have been suggested as a means to improve memory and prevent age-related decline. However, it is unclear whether those effects remain stable over time or are related specifically to negative energy balance during the weight loss phase of CR. Using a randomized interventional design, we investigated changes in recognition memory and neural correlates in postmenopausal obese women (n = 19): 1) after intense weight loss in the course of a 12-week low-caloric diet (reduced body weight and negative energy balance) and 2) after having sustained the reduced weight over 4 more weeks (reduced body weight, but energy balance equilibrium). Participants were contrasted to a control group (n = 18) instructed not to change dietary habits. In the CR group, we found improved recognition memory, paralleled by increased gray matter volume in inferior frontal gyrus and hippocampus, and augmented hippocampal resting-state functional connectivity to parietal areas. Moreover, effects were specific for transient negative energy balance and could not be detected after subsequent weight maintenance. Our data demonstrate for the first time in humans that beneficial effects of CR on brain structure and function are due to weight loss rather than an overall reduced weight

Enzyme-Triggered Cargo Release from Methionine Sulfoxide Containing Copolypeptide Vesicles

We have developed a facile, scalable method for preparation of enzyme-responsive copolypeptide vesicles that requires no protecting groups or expensive components. We designed amphiphilic copolypeptides containing segments of water-soluble methionine sulfoxide, M(O), residues that were prepared by synthesis of a fully hydrophobic precursor diblock copolypeptide, poly(l-methionine)65-b-poly(L-leucine0.5-stat-L-phenylalanine0.5)20, M65(L0.5/F0.5)20, followed by its direct oxidation in water to give the amphiphilic M(O) derivative, M(O)65(L0.5/F0.5)20. Assembly of M(O)65(L0.5/F0.5)20 in water gave vesicles with average diameters of a few micrometers that could then be extruded to nanoscale diameters. The M(O) segments in the vesicles were found to be substrates for reductase enzymes, which regenerated hydrophobic M segments and resulted in a change in supramolecular morphology that caused vesicle disruption and release of cargos