13 research outputs found

    THE USE OF 3D SCANNING AND PHOTOGRAMMETRY TECHNIQUES IN THE CASE STUDY OF THE ROMAN THEATRE OF NIKOPOLIS. SURVEYING, VIRTUAL RECONSTRUCTION AND RESTORATION STUDY.

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    The aim of this paper is to present the specific methods by which 3D scanning and photogrammetric techniques were incorporated into the architectural study, the documentation and the graphic restoration study of the monument of the ancient theatre of Nikopolis. Traditional methods of surveying were enhanced by the use of 3D scanning and image-based 3D reconstruction and 3D remodelling and renderings. For this reason, a team of specialists from different scientific fields has been organized. This presented the opportunity to observe every change of the restoration design process, not only by the use of common elevations and ground plans, but also in 3D space. It has been also very liberating to know how the monument will look like in this unique site after the restoration, so as to obtain at the study stage the best intervention decisions possible. Moreover, these modern work tools helped of course to convince the authorities for the accuracy of the restoration actions and finally to make the proposal clear to the public

    Routine method for the simultaneous quantification of 17α-hydroxyprogesterone, testosterone, dehydroepiandrosterone, androstenedione, cortisol, and pregnenolone in human serum of neonates using gas chromatography-mass spectrometry

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    Steroid determination by immunoassays results in significant interferences and inaccurate results. This study describes the development and validation of a new gas chromatographic-mass spectrometric method for the simultaneous quantification of 17α-hydroxyprogesterone (17αOHP), testosterone (T), dehydroepiandrosterone (DHEA), androstenedione (Δ4-A), cortisol (F) and pregnenolone (Preg) in serum of neonates. Steroids were extracted and purified from 0.5 mL serum using diethyl ether and Extrelut mini NT1 column. The extracts were derivatized with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA)/trimethylsilyl iodide (TMSI)/dithioerythritol (DTE) and the resulting trimethylsilyl derivatives were quantified by gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS). The detection limit for all steroids was lower than 0.1 ng/mL. The limit of quantification was 0.1 ng/mL for all steroids except cortisol which was at 0.25 ng/mL. d3-Testosterone and methyltestosterone served as internal standards. Precision for all compounds at the concentrations of 0.5, 1, 5 and 10 ng/mL (n = 10) in fortified steroid-free serum samples ranged from 0.8% to 16.6%. Accuracy was calculated at the concentrations of 0.5, 1, 5 and 10 ng/mL and ranged from -9.2% to 10.6% (n = 10). Linear calibration equations were obtained for all five steroids (0.125-31.25 ng/mL) and for cortisol (0.125-200 ng/mL). Relative recoveries at concentrations 1.0 and 12.5 ng/mL ranged from 70.5% to 97.5%. Absolute recoveries at the same concentrations ranged from 73.2% to 96.6%. Reference intervals were estimated for infants aged from 9 to 40 days. The proposed steroid profile is suitable for routine analysis and provides meaningful data for samples within normal range as well as those with elevated levels. © 2008 Elsevier B.V. All rights reserved

    Simultaneous quantification of 17α-OH progesterone, 11-deoxycortisol, Δ4-androstenedione, cortisol and cortisone in newborn blood spots using liquid chromatography-tandem mass spectrometry

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    Adrenal steroid profiling, including 17α-OH progesterone (17OHP), 11-deoxycortisol (S), Δ4-androstenedione (Δ4-A) and cortisol (F) in blood spots by tandem mass spectrometry, is used for newborn screening to detect congenital adrenal hyperplasia (CAH). Pre-analytical sample processing is critical for assay specificity and accuracy; however, it is laborious and time-consuming. This study describes the development and validation of a new Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) method for the simultaneous quantification of five steroids: 17OHP, S, Δ4-A, F and cortisone (E) in blood spots from newborns. Whole blood was eluted from a 5.00. mm dried blood spot by an aqueous solution containing the deuterium-labeled internal standards d8-17OHP and d4-cortisol. The steroids extracted from blood spot into aqueous solution were subsequently purified via Extelut mini NT1 column using diethylether. The extracts were evaporated and quantified using LC-MS/MS. The detection limit was 0.25. ng/mL for 17OHP and S, 0.4. ng/mL for Δ4-A and 0.5. ng/mL for F and E. The limit of quantification was 0.5. ng/mL for 17OHP, S and Δ4-A and 1. ng/mL for F and E. Precision for 17OHP, S, Δ4-A at concentrations of 0.5, 2, and 8. ng/mL (n= 5) in fortified steroid free serum samples was 1.3-3.5% (intra-assay CV) and 7-14.8% (inter-assay CV). Precision for F and E at concentrations of 5 and 20. ng/mL was 1.5-4.8% (intra-assay, CV%) and 6-15% (inter-assay, CV%). Accuracy was calculated at concentrations of 0.5, 2, and 8. ng/mL for 17OHP, S and Δ4-A and ranged from -0.3 to 0.2%, while for F and E it ranged from -3.2 to 0.2%. Relative recoveries at concentration 2. ng/mL and 8. ng/mL for 17OHP, S, Δ4-A and at 5. ng/mL and 20. ng/mL for F and E ranged from 55% to 80%. Reference intervals were estimated for all steroids in newborns (on day 3). The steroid profile assay herein described is sensitive, specific and accurate and involves a simple pre-analytical sample manipulation; it is therefore suitable for routine analysis and provides data for samples within normal range as well as those with elevated levels. For the first time to our knowledge, cortisone levels are reported in dried blood spots from newborns. © 2011 Elsevier B.V

    Simultaneous Determination of Free Cortisol, Cortisone and their Tetrahydrometabolites in Urine by Single Solvent Extraction and Liquid Chromatography–Tandem Mass Spectrometry

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    A fast, efficient and low-cost high performance liquid chromatography–tandem mass spectrometry methodology was developed and validated for the simultaneous determination of free urinary cortisone, cortisol and their tetrahydro-metabolites. The developed method comprises a simple liquid-liquid extraction with CH2Cl2, followed by reversed-phase liquid chromatography–tandem mass spectrometry (LC–MS/MS) with electrospray ionization (ESI) in positive mode. The baseline chromatographic separation of the analytes, including the stereoisomers tetrahydrocortisol (THF) and allo-THF, was achieved on a Hypersil Gold C18 column with a mobile phase consisting of 0.05%v/v formic acid in water—acetonitrile, using a gradient elution program. The influence of the mobile phase composition and the ESI parameters on the sensitivity of the method was extensively studied. Sample preparation was also optimized, testing two techniques: solid phase extraction (SPE) and liquid-liquid extraction (LLE). Recoveries ranged from 74.7% (a-THF) to 93.5% (cortisol) and the method limits of detection (MLD) ranged from 0.34 ng mL−1 (cortisol) to 1.37 ng mL−1 (THF). Intra- and inter-day coefficient of variation of the assay varied from1.5% (allo-THF) to 13% (tetrahydrocortisone) and from 3.6% (allo-THF) to 14.9% (tetrahydrocortisone), respectively. The method was applied for the analysis of urine samples from 53 healthy individuals with a mean age of 13.96 years in order to estimate the concentration of the five corticosteroids and the ratio of the metabolites. Associations between urinary cortisol/cortisone and serum cortisol/cortisone values were also characterized. © 2019, © 2019 Taylor & Francis Group, LLC

    Skin-to-skin contact after birth and the natural course of neurosteroid levels in healthy term newborns

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    ObjectiveTo determine the postnatal course of neurosteroid levels in relation to gender, mode of delivery and the extent of skin-to-skin (STS) contact during the first days of life in healthy term newborns.Study designProspective observational study of 39 neonates in which parents recorded total duration of STS in the first 2 days and nine neurosteroids (dehydroepiandrosterone-sulfate, progesterone, pregnenolone, pregnenolone-sulfate, allopregnanolone, isopregnanolone, epipregnanolone, pregnanolone and pregnanolone-sulfate) were assayed from blood samples at birth and at 1-2 days of age.ResultsAll nine neurosteroid levels declined significantly during the first 2 days of life. Gender did not significantly affect the change in neurosteroid levels. The decline in neurosteroid levels was generally more pronounced in vaginal deliveries, and there was a trend toward a larger decline with more exposure to STS.ConclusionOngoing studies may better characterize the role of neurosteroids and the influence of STS in more critically ill and premature neonates
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