Changes in Human Hair Induced by UV- and Gamma Irradiation

The effect of UV- and 137Cs gamma radiation on the structural and chemical integrity of human hair was studied to determine the feasibility of using human hair as a non-invasive biomarker of radiation exposure to ionized gamma- and non-ionized UV-radiation. Steady state tryptophan (Trp) fluorescence and chemical analytical methods were used to evaluate the molecular integrity of Trp fluorophores and SH-groups in hair proteins and to assess the radiation induced damage quantitatively. It was found that human hair fibers were progressively damaged by exposure to both UV- and ionized gamma radiation. Damage to the hair was evidenced by a decrease in the fluorescence intensity as a result of observed depletion of the amino acid tryptophan as well as significant reduction in a number of free SH-groups in hair proteins. Hair damage was dose-dependent for exposures between 0 and 10.0 Gy and 0 - 20 J/cm2 of UV-radiation. Additional results demonstrate that hair-fibers exposed to gamma rays, with much higher quantum energy than UV, undergo a smaller extent of changes in Trp fluorescence than when exposed to lower or equal energy of UV-irradiation. The stable Trp fluorophore appears to be extremely sensitive to UV-radiation in contrast to the ionized gamma radiation whose damage is originated from the reaction of free radicals and direct deposition of energy. We conclude that fluorescence spectroscopy represents a useful tool in the quantitative evaluation of the radiation exposure and could also be used for the rapid and non-invasive assessment of radiation dose i.e. biodosimeter. The approach is simple, non-invasive and appears to have considerable potential that enables quantitative evaluation of radiation dose exposure in a single hair fiber.

Role of sex on psychological distress,quality of life,and coping of patients with advanced colorectal and non-colorectal cancer

BACKGROUNDPatients with advanced gastrointestinal cancer must cope with the negative effects of cancer and complications.AIM To evaluate psychological distress,quality of life,and coping strategies in patients with advanced colorectal cancer compared to non-colorectal cancer based on sex.METHODS A prospective,transversal,multicenter study was conducted in 203 patients;101(50%)had a colorectal and 102(50%)had digestive,non-colorectal advanced cancer.Participants completed questionnaires evaluating psychological distress(Brief Symptom Inventory-18),quality of life(EORTC QLQ-C30),and coping strategies(Mini-Mental Adjustment to Cancer)before starting systemic cancer treatment.RESULTS The study included 42.4%women.Women exhibited more depressive symptoms,anxiety,functional limitations,and anxious preoccupation than men.Patients with non-colorectal digestive cancer and women showed more somatization and physical symptoms than subjects with colorectal cancer and men.Men with colorectal cancer reported the best health status.CONCLUSION The degree of disease acceptance in gastrointestinal malignancies may depend on sex and location of the primary digestive neoplasm.Future interventions should specifically address sex and tumor site differences in individuals with advanced digestive cancer.

Emissive displays with transfer-printed assemblies of 8 μm × 15 μm inorganic light-emitting diodes

Displays using direct light emission from microscale inorganic light-emitting diodes(μILEDs)have the potential to be very bright and also very power efficient.High-throughput technologies that accurately and cost-effectively assemble microscale devices on display substrates with high yield are key enablers forμILED displays.Elastomer stamp transfer printing is such a candidate assembly technology.A variety ofμILED displays have been designed and fabricated by transfer printing,including passive-matrix and active-matrix displays on glass and plastic substrates.