ABSTRACT
OBJECTIVES: To evaluate therapeutic phlebotomy (TP) requests for testosterone replacement therapy (TRT) and to highlight the impact to a blood center (BC) or service that provides TP for individuals on TRT. METHODS: Review of TP requests for individuals on TRT at our BC over a 3-year period from 2014 through 2016, as well as the total number of TP collections. RESULTS: Total TPs during 2014, 2015, and 2016 were 475, 500, and 569, respectively. Annual TP collections for patients on TRT were 193, 212, and 239, respectively. TRT patients with TP orders increased 71.4% during this period. After discontinuation of TP services for TRT at our BC, 32% continued to donate as volunteer blood donors at our BC. CONCLUSIONS: Our BC observed increased TP requests for patients on TRT from 2014 through 2016. Our findings suggest that individuals on TRT may be presenting to BCs as volunteer blood donors to avoid charges for TP.
Subject(s)
Androgens/adverse effects , Phlebotomy/methods , Polycythemia/chemically induced , Polycythemia/therapy , Testosterone/adverse effects , Adult , Blood Donors , Humans , Male , Middle Aged , Polycythemia/bloodABSTRACT
The incorporation of structural color into 3D printed parts is reported, presenting an alternative to the need for pigments or dyes for colored parts produced through additive manufacturing. Thermoplastic build materials composed of dendritic block copolymers were designed, synthesized, and used to additively manufacture plastic parts exhibiting structural color. The reflection properties of the photonic crystals arise from the periodic nanostructure formed through block copolymer self-assembly during polymer processing. The wavelength of reflected light could be tuned across the visible spectrum by synthetically controlling the block copolymer molecular weight and manufacture parts that reflected violet, green, or orange light with the capacity to serve as selective optical filters and light guides.
Subject(s)
Color , Coloring Agents/chemical synthesis , Manufacturing Industry , Nanostructures/chemistry , Photons , Pigments, Biological/chemical synthesis , Polymers/chemistry , Printing, Three-Dimensional , Animals , Butterflies/chemistry , Coloring Agents/chemistry , Molecular Structure , Pigments, Biological/chemistry , Polymers/chemical synthesisABSTRACT
Organic photoredox catalysts have been shown to operate organocatalyzed atom transfer radical polymerizations (O-ATRP) using visible light as the driving force. In this work, the effect of light intensity from white LEDs was evaluated as an influential factor in control over the polymerization and the production of well-defined polymers. We posit the irradiation conditions control the concentrations of various catalyst states necessary to mediate a controlled radical polymerization. Systematic dimming of white LEDs allowed for consideration of the role of light intensity on the polymerization performance. The general effects of decreased irradiation intensity in photoinduced O-ATRP were investigated through comparing two different organic photoredox catalysts: perylene and an 3,7-di(4-biphenyl) 1-naphthalene-10-phenoxazine. Previous computational efforts have investigated catalyst photophysical and electrochemical characteristics, but the broad and complex effects of varied irradiation intensity as an experimental variable on the mechanism of O-ATRP have not been explored. This work revealed that perylene requires more stringent irradiation conditions to achieve controlled polymer molecular weight growth and produce polymers with dispersities <1.50. In contrast, the 3,7-di(4-biphenyl) 1-naphthalene-10-phenoxazine is more robust, achieving linear polymer molecular weight growth under relative irradiation intensity as low as 25%, to produce polymers with dispersities <1.50. This finding is significant, as the discovery of highly robust catalysts is necessary to allow for the adoption of successful O-ATRP in a wide scope of conditions, including those which necessitate low light intensity irradiation.
ABSTRACT
A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The procedure is performed under an inert atmosphere using air- and water-exclusion techniques. The outcome of the polymerization is affected by the ratios of monomer, initiator, and catalyst used as well as the reaction concentration, solvent, and nature of the light source. Temporal control over the polymerization can be exercised by turning the visible light source off and on. Low dispersities of the resultant polymers as well as the ability to chain-extend to form block copolymers suggest control over the polymerization, while chain end-group analysis provides evidence supporting an atom-transfer radical polymerization mechanism.