Porcine skin damage thresholds for pulsed nanosecond-scale laser exposure at 1064-nm

2018 ◽  
Author(s):  
Michael P. DeLisi ◽  
Amanda M. Peterson ◽  
Gary D. Noojin ◽  
Aurora D. Shingledecker ◽  
Amanda J. Tijerina ◽  
...  
Keyword(s):  
Laser Exposure ◽  
Skin Damage ◽  
Porcine Skin

Porcine skin damage thresholds for multiple-pulse laser exposure at 1940 nm

2020 ◽  
Author(s):  
Michael P. DeLisi ◽  
Kurt J. Schuster ◽  
Gary D. Noojin ◽  
Amanda J. Tijerina ◽  
Aurora D. Shingledecker ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Laser Exposure ◽  
Skin Damage ◽  
Porcine Skin ◽  
Multiple Pulse

scholarly journals Porcine skin damage thresholds for 0.6 to 9.5 cm beam diameters from 1070-nm continuous-wave infrared laser radiation

2014 ◽  
Vol 19 (03) ◽  
pp. 1 ◽  
Author(s):  
Rebecca L. Vincelette ◽  
Gary D. Noojin ◽  
Corey A. Harbert ◽  
Kurt J. Schuster ◽  
Aurora D. Shingledecker ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Continuous Wave ◽  
Infrared Laser ◽  
Skin Damage ◽  
Porcine Skin

scholarly journals Skin tolerant inactivation of multiresistant pathogens using far-UVC LEDs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Johannes Glaab ◽  
Neysha Lobo-Ploch ◽  
Hyun Kyong Cho ◽  
Thomas Filler ◽  
Heiko Gundlach ◽  
...  
Keyword(s):  
Full Width ◽  
Half Maximum ◽  
Skin Damage ◽  
Postoperative Infections ◽  
Porcine Skin ◽  
Spectral Filter ◽  
Peak Wavelength ◽  
Everyday Clinical Practice ◽  
Multiresistant Pathogens ◽  
Repair Mechanisms

AbstractMultiresistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) cause serious postoperative infections. A skin tolerant far-UVC (< 240 nm) irradiation system for their inactivation is presented here. It uses UVC LEDs in combination with a spectral filter and provides a peak wavelength of 233 nm, with a full width at half maximum of 12 nm, and an irradiance of 44 µW/cm2. MRSA bacteria in different concentrations on blood agar plates were inactivated with irradiation doses in the range of 15–40 mJ/cm2. Porcine skin irradiated with a dose of 40 mJ/cm2 at 233 nm showed only 3.7% CPD and 2.3% 6-4PP DNA damage. Corresponding irradiation at 254 nm caused 15–30 times higher damage. Thus, the skin damage caused by the disinfectant doses is so small that it can be expected to be compensated by the skin's natural repair mechanisms. LED-based far-UVC lamps could therefore soon be used in everyday clinical practice to eradicate multiresistant pathogens directly on humans.

Model predictions and measured skin damage thresholds for 1.54-μm laser pulses in porcine skin

2003 ◽  
Author(s):  
William P. Roach ◽  
James J. Thomas ◽  
Kurt J. Schuster ◽  
Kevin Stockton ◽  
David J. Stolarski ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Skin Damage ◽  
Porcine Skin ◽  
Model Predictions

scholarly journals Porcine skin damage threshold from mid-infrared optical parametric oscillator radiation at 3743 µm

2020 ◽  
Vol 11 (12) ◽  
pp. 7165
Author(s):  
Luguang Jiao ◽  
Chao Wang ◽  
Kaizeng Zhang ◽  
Jiarui Wang ◽  
Zaifu Yang
Keyword(s):  
Optical Parametric Oscillator ◽  
Damage Threshold ◽  
Parametric Oscillator ◽  
Skin Damage ◽  
Porcine Skin ◽  
Mid Infrared ◽  
Optical Parametric

Model predictions and measured skin damage thresholds for 1.54-μm laser pulses in porcine skin

2004 ◽  
Author(s):  
William P. Roach ◽  
Clarence Cain ◽  
Kurt Schuster ◽  
Kevin Stockton ◽  
David Stolarski ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Skin Damage ◽  
Porcine Skin ◽  
Model Predictions

scholarly journals Towards the enhancement of transdermal drug delivery through thermocavitation

2012 ◽  
Vol 1 (3) ◽  
Author(s):  
Juan P. Padilla-Martinez ◽  
Darren Banks ◽  
Julio C. Ramirez-San-Juan ◽  
Ruben Ramos-Garcia ◽  
Feng Sun ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Low Power ◽  
Transdermal Drug Delivery ◽  
Laser Power ◽  
Continuous Wave ◽  
Focal Point ◽  
Skin Surface ◽  
Skin Damage ◽  
Porcine Skin ◽  
Solution Layer

AbstractAlthough for some highly lipophillic drugs the principal barrier to permeate the human skin may reside in the essentially viable epidermal membrane, for most molecules, the stratum corneum (SC) is the rate-limiting barrier to drug delivery. Today, several techniques have been developed to enhance transdermal drug delivery (TDD) by increasing the effective permeability of the SC (e.g., iontophoresis, electroporation, micro-needle, ultrasound, radio frequency and laser radiation). The goal of this study is to investigate the extent to which thermocavitation may be used as a novel alternative method to selectively pierce the SC and thus enhance TDD. Thermocavitation for this purpose is generated by a continuous wave (CW), low power laser beam focused on a highly-absorbing solution topically applied on the skin surface. The absorbed light creates a superheated volume in a tightly localized region followed by explosive phase transition and the formation of vapor-gas bubbles, which expand and later collapse very rapidly emitting intense acoustic shockwaves that disrupt the surface underneath.Thermocavitation bubbles were induced close to the surface of skin models (agar gels) andThe damage observed on agar gel and porcine skin appears to be congruent with the relationship between laser power, focal point, cavitation frequency and extent of damage observed in previous studies. In particular, the greatest damage induced to the agar phantoms was produced with the lowest laser power (∼153 mW) and thinnest solution layer (∼100 μm) used. Similar laser and solution layer settings led to porcine skin damage of ∼80–100 μm in diameter, which was sufficiently large to break the SC and allow the penetration of 4 kDa, FITC-dextran to depths of ∼40–60 μm.This novel approach to achieve cavitation is attractive and seems promising because it can be generated with inexpensive, low power CW lasers, capable of selectively disrupting the SC and allowing the penetration of large, hydrophilic drugs topically applied to the skin.

Chronic Laser Exposure Effects on Rabbit Retina

1972 ◽  
Vol 30 ◽  
pp. 54-55
Author(s):  
Burton B. Silver ◽  
Theodore Lawwill
Keyword(s):  
Laser Irradiation ◽  
Laser Light ◽  
Broad Band ◽  
Argon Laser ◽  
Atropine Sulfate ◽  
Ultrastructural Changes ◽  
Laser Exposure ◽  
Rabbit Retina ◽  
Histological Changes ◽  
Threshold Doses

Dutch-belted 1 to 2.5 kg anesthetized rabbits were exposed to either xenon or argon laser light administered in a broad band, designed to cover large areas of the retina. For laser exposure, the pupil was dilated with atropine sulfate 1% and pheny lephrine 10%. All of the laser generated power was within a band centered at 5145.0 Anstroms. Established threshold for 4 hour exposures to laser irradiation are in the order of 25-35 microwatts/cm2. Animals examined for ultrastructural changes received 4 hour threshold doses. These animals exhibited ERG, opthalmascopic, and histological changes consistent with threshold damage.One month following exposure the rabbits were killed with pentobarbitol. The eyes were immediately enucleated and dissected while bathed in 3% phosphate buffered gluteraldehyde.

Fading of the diaminobenzidine reaction product in the confocal scanning laser microscope

1989 ◽  
Vol 47 ◽  
pp. 146-147
Author(s):  
JS Deitch ◽  
KL Smith ◽  
JW Swann ◽  
JN Turner
Keyword(s):  
Pyramidal Neurons ◽  
Light And Electron Microscopy ◽  
Scanning Laser ◽  
Laser Exposure ◽  
Confocal Scanning Laser Microscope ◽  
Fluorescent Markers ◽  
Before And After ◽  
Staining Protocol ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

Neurons labeled with horseradish peroxidase and reacted with diaminobenzidine (DAB) can be imaged using a confocal scanning laser microscope (CSLM) in the reflection mode. In contrast to fluorescent markers, the DAB reaction product is thought to be stable and can be observed by both light and electron microscopy. We have investigated the sensitivity of the DAB reaction product to laser irradiation, and present the spectrophotometric properties of DAB before and after exposure in the CSLM.Pyramidal neurons in slices of rat hippocampus were injected with biocytin (a biotin-lysine complex), fixed overnight in 4% paraformaldehyde, and vibratome sectioned at 75 μm. Biocytin was detected with avidin-HRP (1:200) in 0.5% Triton X-100, incubated in DAB (0.5 mg/ml) with or without 0.04% nickel ammonium sulfate (Ni), dehydrated, and imaged in a Bio Rad MRC-500 CSLM with an argon ion laser (488 and 514 nm). Spectrophotometric measurements of the soma were made on a Zeiss microspectrophotometer, as a function of laser exposure (100-1000 scans) and staining protocol.

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