170,038 research outputs found
Basics of the magnetic resonance phenomenon.
No full textMagnetic Resonance is increasing its importance as a diagnostic mean. For an
effective and accurate MRI practice, new fundamental principles, which are at the
basis of this phenomenon, must be acquired. In this chapter an extremely
simplified overview of the physical basics of MRI is introduced, to help the
readers understand the principles underlying this complex technique. Basic
physics, T1 and T2 relaxation times, spin echo sequences, which can be acquired
with the now available units, and tissue characteristics are illustrated. For
those who are interested in a further and more detailed reading in this field, a
bibliography is also quoted
A new approach in endodontics to mechanical instrumentation: an ex vivo study: comparison of cycle fatigue resistance of continuous rotary instruments and vertical continuous rotary movement
No full textTelomere length and obesity
No full textAim: To assess the telomere length in apparently healthy obese and normal-weight subjects. Methods: Seventy-six Caucasian subjects were chosen including 53 children (age 8.2 ± 3.5 years) and 23 adults (age 40.5 ± 8.4 years). Among these, 22 (12 children and 10 adults) were obese with a body mass index (BMI, kg/m2) > 2 SD above the norm. Bioelectrical impedance analysis (BIA), measured with a multiple frequency analyzer, was used to estimate body composition. DNA extraction from white blood cells was used to estimate the telomere length by detection of terminal restriction fragments (TRF). Results: No difference was found between the TRF lengths of obese and normal children. Obese adults had shorter TRF lengths than adults who were not obese (mean TRF length difference, -884.5; 95% confidence intervals -1727 to -41.8; t = 2.183; df = 17; p < 0.041). Conclusions: Obese adults have shorter telomeres than their normal-weight counterparts, while this phenomenon is not present in childhood. © 2008 The Author(s)
FESEM evaluation of smear layer removal from conservatively shaped canals: laser activated irrigation (PIPS and SWEEPS) compared to sonic and passive ultrasonic activation—an ex vivo study
No full textBackground: Irrigation of the pulp space is a mandatory step to get rid of all its organic and inorganic content. Activation of the irrigants play a key role in the era of minimally invasive endodontics. The aim of this study was to assess the effectiveness of different irrigants activation methods in removing the smear layer at 1, 3, 5 and 8 mm from the apex from conservatively shaped canals. Methods: Eighty-five human mandibular premolars were selected. Specimens were shaped to TruShape 25/.06 and divided into 5 groups (1 control and 4 test groups) according to the final activation technique (EndoActivator, EA), Ultrasonic (EndoUltra, PUI) and Laser (PIPS and SWEEPS). EDTA (Ethylenediaminetetraacetic acid) followed by NaOCl (Sodium Hypochlorite) and again EDTA were activated for each test group. Specimens were then split longitudinally and observed by Field Emission Scanning Electron Microscopy (FESEM). Blinded evaluation of the presence of smear layer was performed at 1000X magnification, according to a 5-score index system. Comparison between groups were analysed statistically using the Kruskal–Wallis non-parametric analysis of variance. Bonferroni multiple comparison tests were used. Results: At 1 mm only PIPS and SWEEPS performed better than the control group. At 3, 5 and 8 mm from the apex, every activation technique showed statistically significant reduction of smear layer when compared to the control group. PIPS and SWEEPS obtained better cleanliness result compared to EA, while only PIPS was superior to PUI in terms of cleanliness. Conclusions: PIPS and SWEEPS showed the best results in conservative canal preparations. Nowadays, contemporary rotary instruments allow fast and minimally invasive shaping of the endodontic space. In this scenario irrigants’ activation may be regarded as a mandatory step to a favourable clinical outcome
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An electronic system for integrated management of patients’ data and radiological images
No full text
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Occipital intermittent rhythmic delta activity only following eye closure in atypical CNS Salmonellosis
No full textOBJECTIVE: A statement recently published on the base of a large retrospective analysis, report that the occipital intermittent rhythmic delta activity (OIRDA) "is associated with epilepsy but not acute encephalopathy" [Gullapalli and Fountain. J Clin Neurophysiol 2003;20:35-41]. Our aim is to report, the exception from a child with an intermittent fever, in which the finding of an occipital intermittent rhythmic delta activity (OIRDA) following the eye closure in the EEG recording was the first clinical sign addressing to a CNS involvement.
METHODS: To review the record from a five-year-old girl with a normal basal electroencephalogram and OIRDA that only appeared following eye closure.
RESULTS: We found OIRDA associated with atypical CNS Salmonellosis. Brain MRI and CSF examination confirmed an acute encephalopathy, which was due to Salmonella infection. The only symptoms of the infection were episodes of nightly fever that had lasted for four weeks, sometimes associated with headache and vomiting. Both OIRDA only induced by eye closing and other symptoms disappeared after starting antimicrobial therapy.
CONCLUSIONS: OIRDA only following eye closure is a non-specific abnormality and the present findings, based on a single case, merely indicate that intracranial infection is among the possible causes.
SIGNIFICANCE: The new clinical association is certainly worth recording, as the presence of this electrophysiological sign may provoke clinicians to then delve further into a diagnostic work up.
PMID:15979938[PubMed - indexed for MEDLINE
- …
