Search results for "bleaching"
showing 10 items of 107 documents
Autofluorescence imaging of basal cell carcinoma by smartphone RGB camera
2015
The feasibility of smartphones for in vivo skin autofluorescence imaging has been investigated. Filtered autofluorescence images from the same tissue area were periodically captured by a smartphone RGB camera with subsequent detection of fluorescence intensity decreasing at each image pixel for further imaging the planar distribution of those values. The proposed methodology was tested clinically with 13 basal cell carcinoma and 1 atypical nevus. Several clinical cases and potential future applications of the smartphone-based technique are discussed.
Thioflavin T templates amyloid β(1–40) conformation and aggregation pathway
2015
Aβ(1-40) peptide supramolecular assembly and fibril formation processes are widely recognized to have direct implications in the progression of Alzheimer's disease. The molecular basis of this biological process is still unknown and there is a strong need of developing effective strategies to control the occurring events. To this purpose the exploitation of small molecules interacting with Aβ aggregation represents one of the possible routes. Moreover, the use specific labeling has represented so far one of the most common and effective methods to investigate such a process. This possibility in turn rests on the reliability of the probe/labels involved. Here we present evidences of the effe…
Proteomics of CaCO3 biomineral-associated proteins: how to properly address their analysis.
2013
8 pages; International audience; In a recent editorial (Proc. Natl. Acad. Sci., 2013 110, E2144-E2146) and elsewhere, questions have been raised regarding the experimental practices in relation to the proteomic analysis of organic matrices associated to the biomineralized CaCO3 skeletons of metazoans such as molluscan shells and coral skeletons. Indeed, although the use of new high sensitivity MS technology potentially allows to identify a greater number of proteins, it is also equally (or even more) sensitive to contamination of residual proteins from soft tissues, which are in close contact with the biomineral. Based on our own past and present experimental know-how-observations that are …
NMR Study of Kraft Pulp Mill Waste and Natural Humic Substances
1988
High field proton NMR spectroscopy in DMSO-d6 solution is applied for structural analysis of main high molecular fractions of natural humus and waste lignin from kraft pulp mill. The spectra are similar in great part. Main differences appear in p-disubstituted benzene proton and -CH2 -CO-proton signals which are absent in spectrum of waste lignin obviously due to chlorination. A new observation of 51 Hz 1:1:1 triplet in both spectra is discussed.
Modular Paradigm for Composites: Modeling Hydrothermal Degradation of Glass Fibers
2021
Fiber-reinforced composite materials are often used in structural applications in humid, marine, and offshore environments. Superior mechanical properties are compromised by environmental ageing and hydrolytic degradation. Glass fibers are the most broadly used type of fiber reinforcement to date. However, they are also most severely affected by environmental degradation. The glass fiber degradation rates depend on: (1) glass formulation; (2) environmental factors: pH, T, stress; (3) sizing; (4) matrix polymer; (5) fiber orientation and composite layup. In this short review (communication), seven modules within the Modular Paradigm are reviewed and systematized. These modeling tools, encomp…
Novel core–shell (TiO2@Silica) nanoparticles for scattering medium in a random laser: higher efficiency, lower laser threshold and lower photodegrada…
2013
There has been growing interest in scattering media in recent years, due to their potential applications as solar collectors, photocatalyzers, random lasers and other novel optical devices. Here, we have introduced a novel core-shell scattering medium for a random laser composed of TiO2@Silica nanoparticles. Higher efficiency, lower laser threshold and long photobleaching lifetime in random lasers were demonstrated. This has introduced a new method or parameter (fraction of absorbed pumping), which opens a new avenue to characterize and study the scattering media. Optical chemical and colloidal stabilities were combined by coating a suitable silica shell onto TiO2 nanoparticles.
Multispectral, Fluorescent and Photoplethysmographic Imaging for Remote Skin Assessment
2017
Optical tissue imaging has several advantages over the routine clinical imaging methods, including non-invasiveness (does not change the structure of tissues), remote operation (avoids infection) and ability to quantify the tissue condition by means of specific image parameters. Dermatologists and other skin experts need compact (preferably pocket-size), self-sustained and easy-to-use imaging devices. The operational principles and designs of ten portable in-vivo skin imaging prototypes developed at the Biophotonics Laboratory of Institute of Atomic Physics and Spectroscopy, University of Latvia during the recent five years are presented in this paper. Four groups of imaging devices are con…
Effect of postbleaching application of an antioxidant on enamel bond strength of three different adhesives
2010
Objectives: The aim of this study was to compare the shear bond strength (sbs) of three different adhesives on bleached enamel immmmediately after bleaching, bleached/delayed for 1 week, and bleached/applied antioxidizing agent. Study Design: The enamel surfaces of 144 freshly extracted incisors without any caries and restorations were flattened and divided into 12 groups. The following adhesives were investigated: Optibond FL (OFL) (three-step etch&rinse), Optibond Solo Plus (OSP) (two-step etch&rinse), Optibond All-in-One (OA) (one-step self-etch), (Kerr, Orange, USASA). Unbleached enamel groups were prepared as negative controls. The remainder surfaces were bleached with 20% Opalescent P…
Desmosomes: interconnected calcium-dependent structures of remarkable stability with significant integral membrane protein turnover
2002
Desmosomes are prominent cell adhesion structures that are major stabilizing elements, together with the attached cytoskeletal intermediate filament network, of the cytokeratin type in epithelial tissues. To examine desmosome dynamics in tightly coupled cells and in situations of decreased adhesion, fluorescent desmosomal cadherin desmocollin 2a (Dsc2a) chimeras were stably expressed in human hepatocellular carcinoma-derived PLC cells (clone PDc-13) and in Madin-Darby canine kidney cells (clone MDc-2) for the continuous monitoring of desmosomes in living cells. The hybrid polypeptides integrated specifically and without disturbance into normal-appearing desmosomes that occurred in associati…
Assessment of Oxygen Expansion during Internal Bleaching with Enamel and Dentin: A Comparative In Vitro Study.
2021
Internal bleaching is a conservative, non-invasive, and simple treatment that is frequently performed in daily clinical practice. The present in vitro study analyzes the oxygen expansion of different bleaching agents resulting from the oxidation reaction when interacting with enamel and dentin. Enamel and dentin were crushed separately until obtaining a fine powder with particles of an approximate size between 0.06 and 0.2 mm. Each enamel and dentin sample were mixed with 37% carbamide peroxide (CP 37%), 30% hydrogen peroxide (HP 30%), sodium perborate (SP) combined with HP 30% (HP 30% + SP) and SP with distilled water (SP). A total of 280 1 mm diameter glass tubes were used with 70 for eac…