Alteration of optical and morphological properties of polycarbonate illuminated by visible/IR laser beams

In this paper we investigate the effects of visible to near infrared (NIR) laser illumination on the optical transmission (OT) and morphological changes (MC) of thin, curved surfaces of polycarbonate (PC) as employed by industry. The second harmonic of Nd:YAG laser (532 nm) and two diode lasers (665 and 980 nm) were used as sources. We have shown that the morphological changes and optical transmission of the PC elements are influenced by visible to infrared coherent illumination. The morphological changes of the PC surfaces are determined using atomic force microscopy (AFM), demonstrating the appreciable changes caused by the shorter wavelengths (higher energy). When analyzing the OT spectra of PC thin films, a measurable decrease in the OT of the PC surfaces which were illuminated by 532, 665 and 980 nm, in particular 532 nm, for energy densities greater than 25 J/cm^2 can be seen

Attention-deficit/hyperactivity disorder (ADHD) association with the DAT1 core promoter -67 T allele

Association between attention deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a polymorphism (a 40 bp variable number of tandem repeats) in the dopamine transporter gene (DAT1) has been reported by several groups. In this study, we examined whether either allele of the DAT1 core promoter -67 functional polymorphism is associated with ADHD in a case/control study. The allele and genotype frequencies of the polymorphism were studied in 110 patients and 120 controls, which were matched on the basis of sex, age and ethnicity. The genotype frequencies in the patients group were as follows: AA 19.2; AT 65.2; TT 15.4 vs. the genotype frequencies in the control group: AA 47.5; AT 43.3; TT 9.2 �2 = 20.73, df = 2, P � 0.0001. The T allele of the -67A/T polymorphism revealed an �1.56-fold excess in the patients group comparing with the controls �2 = 14.50, df = 1 (P � 0.001). For the first time, these findings provide tentative evidence of the contribution of the DAT1 gene core promoter polymorphism to the etiopathophysiology of ADHD at least in the Iranian population that we have studied. Further work is warranted to confirm this finding and to assess its generalization to other ethnic groups. © 2006 Elsevier B.V. All rights reserved