Adjacent guanines as preferred sites for strand breaks in plasmid DNA irradiated with 193 nm and 248 nm UV laser light

1996 ◽  
Vol 32 (1-2) ◽  
pp. 97-102 ◽  
Author(s):  
Helmut Sies ◽  
Wolfgang A. Schulz ◽  
Steen Steenken
Keyword(s):  
Plasmid Dna ◽  
Laser Light ◽  
Uv Laser ◽  
Strand Breaks ◽  
193 Nm

Modification on chemical and optical properties of PADC polymer by ArF laser (193 nm) irradiation

2015 ◽  
Vol 35 (4) ◽  
pp. 359-365 ◽  
Author(s):  
Banin Shakeri Jooybari ◽  
Hossein Afarideh ◽  
Mohammad Lamehi Rachti ◽  
Mitra Ghergherehchi
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Free Radical ◽  
Laser Light ◽  
Degradation Mechanism ◽  
Uv Laser ◽  
Photo Degradation ◽  
Free Radical Generation ◽  
Radical Generation ◽  
193 Nm

Abstract Poly allyl diglycol carbonate (PADC) has been irradiated by ArF(UV)-laser light (wavelength 193 nm) at different fluences and pulse numbers in order to investigate the photo degradation of chemical molecular structure. The photo-induced chemical reactions and photo-degradation mechanism at the irradiated polymer surface have been clarified by ultraviolet-visible (UV-Vis) spectrum and FTIR spectrum analyses. Optical and surface modifications of irradiated samples have been studied by refractive index and water contact angle measurements. Using the UV-Vis spectra, Urbach’s energy (Eu), indirect and direct band gaps energy (Eg) of unirradiated and UV-laser irradiated samples were determined. The UV-Vis and FTIR spectra analysis show that photo degradation and photo oxidation of polymer caused free-radical generation. In the presence of air, free-radical generation induced by UV-laser light followed by bond scission and cross-linking process will finally produce new products. New product generation can be affected on chemical and optical properties of irradiated samples. The irradiated PADC at various fluences in the range of medium to high demonstrate improvement of refractive index, and this is highly important in plastic lens technology. The obtained results reveal that chemical modification could affect track parameters when PADC is used as a nuclear track detector.

PHOTOLESIONS AND BIOLOGICAL INACTIVATION OF PLASMID DNA ON 254 nm IRRADIATION AND COMPARISON WITH 193 nm LASER IRRADIATION

1993 ◽  
Vol 58 (4) ◽  
pp. 477-485 ◽  
Author(s):  
Gagik G. Gurzadyan ◽  
Helmut Gorner ◽  
Dietrich Schulte-Frohlinde
Keyword(s):  
Laser Irradiation ◽  
Plasmid Dna ◽  
193 Nm

scholarly journals Fragmentation of Plasmid DNA Produced by Gamma Radiation: A Theoretical Approach

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
R. A. S. Silva ◽  
J. D. T. Arruda-Neto ◽  
L. Nieto
Keyword(s):  
Plasmid Dna ◽  
Fragment Size ◽  
Power Laws ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
Starting Point ◽  
Dna Strands ◽  
High Let ◽  
Fragment Distribution ◽  
Dna Strand

Breaks in DNA, resulting in fragmented parts, can be produced by ionizing radiation which, in turn, is the starting point in the search for novel physical aspects of DNA strands. Double-strand breaks in particular cause disruption of the DNA strand, splitting it into several fragments. In order to study effects produced by radiation in plasmid DNA, a new simple mechanical model for this molecule is proposed. In this model, a Morse-like potential and a high-LET component are used to describe the DNA-radiation interaction. Two power laws, used to fit results of the model, suggest that, firstly, distribution of fragment size is nonextensive and, secondly, that a transition phase is present in the DNA fragment distribution pattern.

Gentle surface analysis with intense UV laser light

1986 ◽  
Author(s):  
C. H. Becker ◽  
M. M. Freund
Keyword(s):  
Surface Analysis ◽  
Laser Light ◽  
Uv Laser

Photo-alignment of liquid crystals in micro capillaries with point-by-point irradiation

2014 ◽  
Vol 22 (3) ◽  
Author(s):  
A. Siarkowska ◽  
M. Jóźwik ◽  
S. Ertman ◽  
T. Woliński ◽  
V. Chigrinov
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Azo Dye ◽  
Laser Light ◽  
Alignment Method ◽  
Uv Laser ◽  
Orientation Control ◽  
Photo Alignment

AbstractA photo-alignment method for micro capillaries based on the SD-1 azo-dye is demonstrated. In this work a liquid-crystal molecules aligning layer is created by point-by-point irradiation of the azo-dye film by using an UV laser light. The method opens up new possibilities for an improved molecules’ orientation control in both glass- and polymer-based photonic liquid crystal fibres.

Development of Laser Dresser for Resin Bonded Diamond Wheel

2007 ◽  
Vol 329 ◽  
pp. 169-174 ◽  
Author(s):  
Hiroshi Matsuura ◽  
Kazuhiro Hane ◽  
Yasuhiro Kunieda ◽  
Nobuhito Yoshihara ◽  
Ji Wang Yan ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Laser Light ◽  
Laser Energy ◽  
Uv Light ◽  
Mechanical Damage ◽  
Diamond Wheel ◽  
The State ◽  
Uv Laser ◽  
Wheel Surface ◽  
Core Diameter

The state of the wheel surface after dressing is important for processing of a surface to the nano-order level. A laser dresser was developed using ultraviolet (UV) laser light, which imparts no mechanical damage to the resin bond. One feature of this system is that UV laser energy is transmitted by a special optical fiber for UV light, and is transmitted only to the resin bond. Using this newly developed laser dresser, it was possible to ablate the resin bond to a depth of over 2 microns using a fiber with a core diameter of 200 microns.

scholarly journals CARS and Fluorescent study of ignition of H2/O2 mixtures upon photodissociation of O2 molecular

2018 ◽  
Vol 209 ◽  
pp. 00010
Author(s):  
Vitaly Kobtsev ◽  
Sergey Kostritsa ◽  
Dmitrii Kozlov ◽  
Alexey Pelevkin ◽  
Valery Smirnov ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Combustion Chamber ◽  
Test Bench ◽  
Combustion Process ◽  
Kinetic Mechanism ◽  
Uv Laser ◽  
Chain Reactions ◽  
Ignition And Combustion ◽  
193 Nm ◽  
Experimental Test Bench

The research is devoted to gas mixtures ignition by UV laser radiation. The dissociation of O2 molecules by a pulse of excimer ArF laser radiation at 193-nm wavelength with formation of the chemically active oxygen atoms initiating chain reactions which cause ignition of H2/O2 mixture was employed. The experimental test bench was created with CARS and fluorescent techniques for experimental investigation of some peculiarities of mixture ignition and combustion caused by such photo-dissociation, at conditions typical for combustion chamber. Two-dimensional numerical modeling of combustion process in model combustion chamber, based on kinetic mechanism of H2 oxidation including atom O(1P) and radicals OH(A2Σ+), was performed.

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