Organic solid-state distributed feedback dye laser with a nonmorphological modification grating

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in APPLIED PHYSICS LETTERS. 77(17):2641-2643 (2000) and may be found at https://doi.org/10.1063/1.1320034 .ArticleAPPLIED PHYSICS LETTERS. 77(17):2641-2643 (2000)journal articl

Apoptotic cell death and cell proliferative activity in the rat fetal central nervous system from dams administered with ethylnitrosourea (ENU)

Ethylnitrosourea (ENU), a weii known DNA alkylating agent, induces anomalies in the central nervous system (CNS), craniofacial tissues and male reproductive organs, and the enhancement of apoptosis is found in these tissues immediately after the administration of ENU (Katayama et al., 2000a). In this study, pregnant rats were treated with 6Omgíkg of ENU at day 13 of gestation, and kinetics of apoptotic cells, mitotic cells and bromodeoxyuridine (BrdU)-positive cells in the fetal CNS were examined from 3 to 48 hours after the treatment (HAT). From 3 HAT, a significant increase in the number of apoptotic cells and a significant decrease in the number of mitotic cells were detected in the fetal CNS, and BrdU-positive cells significantly decreased in accordance with the increase in the number of apoptotic cells. The present results strongly suggest that both excess cell death by apoptosis and cell growth arrest indicated by decreased number of mitotic cells and BrdU-positive cells may have a close relation to the later occurrence of microencephaly following ENU-administration, and that ENU affects mainly S-phase cells and causes apoptosis

Biofunctionalization of vertically aligned diamond nanowires

Vertically aligned diamond nanowires are biofunctionalized using aminophenyl linker molecules to bond nucleic acid molecules with a well-defined nanometer-sized spacing to the transducer. This novel DNA biosensor combines the outstanding electrochemical properties of diamond as a transducer with the controlled bonding of DNA molecules to the tips of nanowires by use of an electrochemical attachment scheme. Nucleic acid molecules are bonded in this way and dispersed to the transducer, giving rise to optimized hybridization kinetics of DNA. Negatively charged redox mediator molecules (Fe(CN)(6)(3-)/(4-)) are applied for DNA-hybridization sensing. Voltammetric detection of DNA hybridization by differential pulse voltammetry is performed with respect to its sensitivity and reproducibility. On a sensor are of 0.03 cm(2), a detection limit of 2.0 pm is achieved. As for the chemical stability of the DNA bonding to the diamond nanowires, no degradation over 30 hybridization/denaturation cycles could be detected. By use of this dilute DNA arrangement, single-base mismatch discrimination is achieved. Under the same conditions, smooth diamond modified with phenyl is not suitable for amperometric DNA sensing