Search results for "surface [detector]"
showing 10 items of 2064 documents
Buildup of Ultrathin Multilayer Films by a Self-Assembly Process: II. Consecutive Adsorption of Anionic and Cationic Bipolar Amphiphiles and Polyelec…
1991
We have recently reported on the consecutive physisorption of anionic and cationic bipolar amphiphiles onto charged surfaces, adsorbed out of aqueous solutions [1]. Here, we extend our previous concept to multipolar compounds such as polyelectrolytes. In contrast to the bipolar amphiphile system, it is not necessary to separate single charges by a rigid unit, when the polyelectrolyte is adsorbed from sufficiently concentrated solutions. In this case the physisorbed layer does not bind with all ionic groups to the surface and exposes free ionic groups at the new film/solution interface. Therefore a polyelectrolyte layer can replace a layer of bipolar amphiphiles in the consecutive buildup of…
Adsorption of atomic and molecular oxygen on the LaMnO3(001) surface: ab initio supercell calculations and thermodynamics.
2008
We present and discuss the results of ab initio DFT plane-wave supercell calculations of the atomic and molecular oxygen adsorption and diffusion on the LaMnO(3) (001) surface which serves as a model material for a cathode of solid oxide fuel cells. The dissociative adsorption of O(2) molecules from the gas phase is energetically favorable on surface Mn ions even on a defect-free surface. The surface migration energy for adsorbed O ions is found to be quite high, 2.0 eV. We predict that the adsorbed O atoms could penetrate the electrode first plane when much more mobile surface oxygen vacancies (migration energy of 0.69 eV) approach the O ions strongly bound to the surface Mn ions. The form…
Microscopic Insights into the Fluorite/Water Interfaces from Vibrational Sum Frequency Generation Spectroscopy
2016
Water/mineral interfaces are central to a wide range of environmental and technological processes. In this report we provide a quantitative, molecular-level understanding of the CaF2/water interface using Density Functional Theory-based molecular dynamics simulations. In particular through the comparison of calculated Vibrational Sum Frequency Generation spectra to the experimental ones, we give a structural characterisation of the interface at different pH. At low pH, the surface is positively charged, causing a substantial degree of water ordering. Our results suggest that the surface charge originates from the dissolution of fluoride ions of the topmost layer, rather than from proton ads…
Corneal confocal scanning laser microscopy in patients with dry eye disease treated with topical cyclosporine
2017
Purpose To investigate the effect of cyclosporine on corneal ultrastructure and on major signs and symptoms of patients with dry eye disease.Patients and methods In this prospective cohort study, patients with dry eye disease were treated with a drop of cyclosporine 0.05% twice daily. Clinical evaluation was carried out at baseline and at months 1, 3, and 6. All patients completed the Ocular Surface Disease Index (OSDI) questionnaire, and tear film break-up time (BUT), fluorescein and lissamine green staining, and Schirmer test were carried out. In vivo confocal microscopy was also performed and epithelial cellular density, keratocyte activation, and subbasal plexus morphology were assessed…
Ability for Voice Recognition Is a Marker for Dyslexia in Children
2014
A recent voice recognition experiment conducted by Perrachione, Del Tufo, and Gabrieli (2011) revealed that, in normal adult readers, the accuracy at identifying human voices was better in the participants’ mother tongue than in an unfamiliar language, while this difference was absent in a group of adults with dyslexia. This pattern favored a view of dyslexia as due to “fundamentally impoverished native-language phonological representations.” To further examine this issue, we conducted two voice recognition experiments, one with children with/without dyslexia, and the other with adults with/without dyslexia. Results revealed that children/adults with dyslexia were less accurate at identify…
Influence of Scapular Position on the Core Musculature Activation in the Prone Plank Exercise
2017
Cortell-Tormo, JM, García-Jaén, M, Chulvi-Medrano, I, Hernández-Sánchez, S, Lucas-Cuevas, ÁG, and Tortosa-Martínez, J. Influence of scapular position on the core musculature activation in the prone plank exercise. J Strength Cond Res 31(8): 2255-2262, 2017-Prone plank is a widely used exercise in core stability training. Research has shown that pelvic tilt plays an important role on the electromyographic (EMG) activation of core musculature. However, the influence of scapular position on EMG activation is currently unknown. Therefore, this study evaluated the influence of scapular position on the core muscles during a prone plank. Surface EMG of the rectus abdominis (RA), external oblique (…
How Do Different Digital Displays Affect the Ocular Surface?
2020
Digital display use has been accepted as a contributing factor to dry eye disease. Nowadays, plenty of new models of digital displays have been developed, and the differences in their nature and the ways in which they are set and used may contribute to differences in the eye-related problems they cause.This study aimed to analyze the differences in ocular surface, tear film, and visual fatigue parameters after reading on different digital displays, with and without initial instillation of artificial tears.Thirty-one healthy individuals ranging in age from 20 to 26 years (mean ± standard deviation, 21.26 ± 1.73 years) were included in this prospective clinical study. Subjects' ocular surface…
A 12-month Prospective Study of Tear Osmolarity in Contact Lens Wearers Refitted with Daily Disposable Soft Contact Lenses
2020
SIGNIFICANCE Tear osmolarity has been reported as one of the best diagnostic tests for dry eye disease and its management. Contact lens wear is thought to influence tear homeostasis. Understanding how regular wear of contact lenses and their type affect tear osmolarity is important. PURPOSE The purpose of this study was to assess changes in tear osmolarity and ocular symptoms over a period of 12 months following refitting contact lens wearers with daily disposable contact lenses. METHODS Fifty subjects aged (mean ± SD) 26 ± 4 years were refitted with either silicone-hydrogel (delefilcon A, SiHy, n = 34) or hydrogel (omafilcon A, Hy, n = 16) daily disposable soft contact lenses. Study includ…
Meibomian glands structure in daily disposable soft contact lens wearers: a one‐year follow‐up study
2020
Purpose To assess the impact of daily disposable soft contact lenses on meibomian gland morphology over a period of 12 months. Methods Forty-one subjects (33 experienced and 8 neophytes) were fitted with either silicone-hydrogel or hydrogel daily contact lenses. The study protocol included four visits: baseline, day-2 for contact lens fit and follow-up measurements, as well as after 6 and 12 months of lens wear. Non-contact infrared meibography images were acquired with Keratograph 5M topographer (www.oculus.de) and analysed with an automated method, which objectively estimates the area of gland atrophy, gland length and width, number of glands and gland irregularity. Protocol at follow-up …
Short-Term Impact of FS-LASIK and SMILE on Dry Eye Metrics and Corneal Nerve Morphology
2020
PURPOSE To analyze the short-term (up to 1 month) clinical outcomes in patients undergoing corneal laser refractive surgery and the impact on dry eye disease (DED) metrics and corneal nerves using in vivo confocal microscopy (IVCM). METHODS The unaided distance visual acuity, corrected distance visual acuity, and spherical equivalent refraction (SEQ) were determined in 16 and 13 patients undergoing FS-LASIK and SMILE, respectively. DED metrics assessed were Ocular Surface Disease Index, Dry Eye Questionnaire 5-items (DEQ-5), tear film osmolarity, tear meniscus height, noninvasive keratograph breakup time (NIKBUT), ocular staining, and meibomian gland atrophy. An automated analysis of cornea…