Search results for " Microscopy"
showing 10 items of 1617 documents
Magnetic Resonance Microscopy at 14 Tesla and Correlative Histopathology of Human Brain Tumor Tissue
2011
Magnetic Resonance Microscopy (MRM) can provide high microstructural detail in excised human lesions. Previous MRM images on some experimental models and a few human samples suggest the large potential of the technique. The aim of this study was the characterization of specific morphological features of human brain tumor samples by MRM and correlative histopathology. We performed MRM imaging and correlative histopathology in 19 meningioma and 11 glioma human brain tumor samples obtained at surgery. To our knowledge, this is the first MRM direct structural characterization of human brain tumor samples. MRM of brain tumor tissue provided images with 35 to 40 µm spatial resolution. The use of …
Centrifugal (inside-out) enhancement of liver hemangiomas: a possible atypical appearance on contrast-enhanced US.
2007
Abstract Objective To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods Baseline and SonoVue ® -enhanced ultrasonography of 92 patients with 158 liver hemangiomas – considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up – were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) …
Visualization of corneal vascularization in peripheral hypertrophic subepithelial corneal opacification with OCT angiography.
2018
Purpose The major goal of this study was to test the hypothesis that in patients with peripheral hypertrophic subepithelial corneal opacification (PHSCO), visualization of corneal vessels is better with optical coherence tomography angiography (OCTA) than with conventional slit lamp microphotography. Methods Patients with PHSCO were included in this prospective study. The corneal findings were photographed using a slit lamp camera (Haag Streit BM 900® ) and visualized with anterior-segment OCT (Optovue XR Avanti, Fremont, California, USA). Additionally, OCTA with the Angiovue Imaging™ System was performed in the area of PHSCO. Results Thirty-four eyes of 19 patients (26% male and 74% female…
Evaluating tear clearance rate with optical coherence tomography
2017
Purpose: To assess the early-phase of tear clearance rate (TCR) with anterior segment optical coherence tomography (OCT) and to determine the association between TCR and other clinical measures of the tear film in a group of young subjects with different levels of tear film quality. Methods: TCR was classified as the percentage decrease of the inferior tear meniscus height 30s after instillation of 5uL 0.9% saline solution. Fifty subjects (32F and 18M) aged (mean +/- standard deviation) 25.5 +/- 4.3 years volunteered for the study. It consisted of a review of medical history, Ocular Surface Disease Index (OSDI) questionnaire, tear film osmolarity measurements, slit lamp examination and TCR …
Mechanical Properties of Human Patellar Tendon at the Hierarchical levels of Tendon and Fibril
2012
Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its distinct collagen fibrils would display similar mechanical properties. Human patellar tendons ( n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar …
Confocal microscopy: a valid approach to evaluate the three-dimensional characteristics of root-end cavities
2013
Objective: To analyze, using confocal microscope, the three-dimensional characteristics of the root-end cavity preparations completed in root apices of extracted teeth determining their area, perimeter, circularity and cavo-surface angle. Study design: Thirty-two single-rooted extracted teeth underwent endodontic treatment and apical resection. Root-end cavities were prepared according to 4 protocols, as follows: Group1, stainless steel ultrasonic tips (SST) at 33 KHz power; Group 2, SST at 30 KHz power; Group 3, diamond-coated ultrasonic tips (DCT) at 30 KHz power; and Group 4, DCT at 33 KHz power. Finally, root-end cavity was evaluated using a confocal microscope, recording its area, peri…
Transdermal nortriptyline hydrocloride patch formulated within a chitosan matrix intended to be used for smoking cessation.
2010
The aim of this study was to prepare and characterize both physically and biopharmaceutically, a nortriptyline hydrochloride (NTP-HCl) patch formulated in chitosan.16 g of each chitosan patch formulation (I, II and III, see Table 1 ) was poured onto rectangular glass plates (64 cm²) at a height of 1 mm and dried for 24 h at room temperature. In order to characterize the chitosan patches, polarized microscopy, in vitro skin permeation studies by passive diffusion and iontophoresis and rheological and bioadhesion studies were performed.Polarized microscopy revealed the absence of aggregates and crystal forms of NTP-HCl in all transdermal patches after 30 days of storage. The rheological behav…
Quantitative anatomical differences in central corneal thickness values determined with scanning-slit corneal topography and noncontact specular micr…
2005
PURPOSE This study was designed to analyze the differences in central corneal thickness values determined with noncontact specular microscopy and scanning-slit corneal topography. The measurements were performed on the same eye. METHODS We analyzed the central corneal thickness values of 93 patients (n = 93) by means of noncontact specular microscopy (Topcon SP-2000P noncontact specular microscope, Topcon Corp., Tokyo, Japan) and scanning-slit corneal topography (Orbscan Topography System II, Orbscan Inc., Salt Lake City, UT). One experienced physician performed 3 consecutive central corneal thickness measurements with both devices. RESULTS The central corneal thickness values obtained by m…
Evaluation of saliva as a complementary technique to the diagnosis of COVID-19:a systematic review
2021
Background Infectious disease coronavirus 2019 (COVID-19) is caused by the SARS-CoV-2 virus, and it mainly affects the upper respiratory tract. The gold standard for its diagnosis is real-time reverse transcription polymerase chain reaction (RT-qPCR) performed on a nasopharyngeal swab. In contrast, testing saliva has significant advantages as a diagnostic method. Material and Methods We searched for articles evaluating saliva as a diagnostic method for COVID-19 on the PUBMED/MEDLINE, WEB OF SCIENCE, COCHRANE, and SCIELO platforms. We initially found 233 articles and 20 were selected for inclusion following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol: 18 c…
Monolayers of asymmetrical diethylalkanoat disulfides on gold(111):.the influence of chain length difference on atomic force microscope images
1998
Several symmetrical and asymmetrical long-chain diethylalkanoat disulfides were synthesized and character- ized. The differences in the chain lengths of the disul- fides ranged between zero and five methylene units. Self- assembled monolayers of these disulfides formed on Au(111) surfaces were studied by atomic force microscopy (AFM) in order to obtain information about the origin of the image contrast. Domains with hexagonal lattices (lattice constants 5:2- 5:3 A) were detected for all derivatives, independent of the chain length differences. This indicates that the contrast arises roughly at a depth of 4- 8 A in the monolayers at imag- ing forces between 0: 2a nd 3n N. For SAMs of diethyl…