Solid-phase DNase I footprinting provides a powerful tool for analyzing the sequence-specific interactions of DNA binding proteins. Classically this type of assay requires radioactively labeled DNA molecules. Substitution of the isotope by fluorescein labeling of the DNA fragments enables the analysis of footprint patterns on a standard automated laser fluorescent (A.L.F.) DNA Sequencer. The co...

Terrestrial laser scanning (TLS) is providing exciting new ways to quantify tree and forest structure, particularly above-ground biomass (AGB). We show how TLS can address some of the key uncertainties and limitations of current approaches to estimating AGB based on empirical allometric scaling equations (ASEs) that underpin all large-scale estimates of AGB. TLS provides extremely detailed non-...

We demonstrate versatility of femtosecond direct laser writing (DLW) technique for microstructuring of iron-doped and as-grown lithium niobate crystals. Formation of extended, metastable, and re-writable refractive index modulation structures is achievable via fast local photorefractive modification of refractive index at the focus of the writing laser beam, with a modulation of up to ∆n ~ 10, ...

PURPOSE To determine the ablation depths of customized myopic excimer laser photoablations performed to change corneal asphericity after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). METHODS A mathematical model of aspheric myopic corneal laser surgery was generated. The initial corneal surface was modeled as a conic section of apical radius R(1) and asphericity ...

Steep central island (SCI) formation after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) represents a major drawback in the visual rehabilitation of patients after refractive laser surgery. Because of the small size of SCIs, current ablation algorithms are unable to properly calculate an ablation pattern for customized retreatment. We present the use of a new ablati...

Purpose To determine the unknown preoperative K readings (Kpre) to be used in history-based methods, for intraocular lens (IOL) power calculation in patients who have undergone myopic photorefractive keratectomy (PRK). Methods A regression formula generated from the left eyes of 174 patients who had undergone PRK for myopia or for myopic astigmatism was compared with other methods in 168 righ...

BACKGROUND This study aimed to compare two doses of Mitomycin C in reducing haze formation after photorefractive keratectomy. METHODS 170 eyes of 85 patients enrolled; in each patient one eye randomly assigned to be treated by low dose intraoperative MMC (LDMMC) and other eye by standard dose MMC (SDMMC). Then the patients were followed up to 6 months and refraction, Uncorrected Distant Visua...

BACKGROUND/AIMS The Fas-Fas ligand system is thought to be involved in stromal cell apoptosis after corneal wounding. The aim was to measure changes in human tear fluid levels of soluble Fas (sFas) and Fas ligand (sFasL) following myopic photorefractive keratectomy (PRK). METHODS Tear samples of 59 patients were collected preoperatively, and 1 or 2 days after PRK. Tear fluid sFas or sFasL con...

OBJECTIVE To perform a quantitative analysis of keratocyte density in human corneas after photorefractive keratectomy (PRK). METHODS In a prospective comparative trial, 24 eyes of 14 patients received PRK to correct refractive errors of between -1.25 diopters (D) and -5.75 D. Corneas were examined by using confocal microscopy before and 1 day, 5 days, and 1, 3, 6, 12, 24, and 36 months after ...

PURPOSE To characterize the velocity of epithelial migration after photorefractive keratectomy (PRK) with 3 different corneal ablation patterns. SETTING Department of Ophthalmology, Catholic University of Rome, Rome, Italy. METHODS Fifteen patients (30 eyes) with mild to moderate myopia and with simple to compound myopic astigmatism were enrolled for this study. The surgical procedure consi...