Search results for " dose"
showing 10 items of 593 documents
Oral glutathione increases hepatic glutathione and prevents acetaminophen toxicity
1990
Administration of oral glutathione (GSH) increases hepatic GSH levels in fasted rats, in mice treated with GSH depletors such as diethylmaleate and in mice treated with high doses of paracetamol. An increase in hepatic GSH levels after administration of oral GSH does not occur in animals treated with buthionine suphoximine, an inhibitor of GSH synthesis. Administration of oral GSH leads to an increase in the concentration of L-cysteine, a precursor of GSH, in portal blood plasma. Oral administration of L-methio-nine to fasted rats produced a significant decrease of hepatic ATP, but not in fed rats. Administration of N-acetyl-cysteine or GSH did not affect the hepatic ATP levels. The results…
Spacers and Valved Holding Chambers—The Risk of Switching to Different Chambers
2020
© 2020 The Authors. Published by Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Evaluation of interpolation methods for TG-43 dosimetric parameters based on comparison with Monte Carlo data for high-energy brachytherapy sources.
2010
Purpose The aim of this work was to determine dose distributions for high-energy brachytherapy sources at spatial locations not included in the radial dose function gL(r) and 2D anisotropy function F(r,θ) table entries for radial distance r and polar angle θ. The objectives of this study are as follows: 1) to evaluate interpolation methods in order to accurately derive gL(r) and F(r,θ) from the reported data; 2) to determine the minimum number of entries in gL(r) and F(r,θ) that allow reproduction of dose distributions with sufficient accuracy. Material and methods Four high-energy photon-emitting brachytherapy sources were studied: 60Co model Co0.A86, 137Cs model CSM-3, 192Ir model Ir2.A85…
O26 Population pharmacokinetic meta-analysis of individual data to design the first randomized efficacy trial of vancomycin in neonates and young Inf…
2019
BackgroundIn the absence of consensus, the present meta-analysis was performed to determine an optimal dosing regimen of vancomycin for neonates.MethodsA ‘meta-model’ using NONMEM with 4894 concentrations from 1631 neonates was built and Monte Carlo simulations were performed to design an optimal intermittent infusion, aiming at reaching a target AUC0-24 of 400 mg*h/L at steady state in at least 80% of neonates.ResultsA two-compartment model best fitted the data. Current weight, post-menstrual age (PMA) and serum creatinine were the significant covariates for clearance (CL). After model validation, simulations showed that a loading dose (25 mg/kg) and a maintenance dose (15 mg/kg twice dail…
The gas chromatography/mass spectrometry can be used for dose estimation in irradiated pork
2009
Abstract Food safety can be improved using ionizing radiation to reduce food spoilage and to extend its shelf life. The gas chromatography/mass spectrometry (GC/MS) has been validated by the European Community as a powerful method to identify irradiated food containing fat. The preliminary goals of our research were: (i) to set up this method, based on the detection of radiation induced 2-dodecylcyclobutanones (2-DCB) in pork muscle samples and (ii) to check the microbiological efficacy of the treatment. The main objective was to render the GC/MS a quantitative technique for dose estimation, through the measurement of the 2-DCB concentration in the irradiated sample. Our results show that t…
Fluence rate or cumulative dose? : Vulnerability of larval northern pike (Esox lucius) to ultraviolet radiation
2007
Newly hatched larvae of northern pike were exposed in the laboratory to four fluence rates of ultraviolet radiation (UVR; 290–400 nm) over three different time periods, resulting in total doses ranging from 3.0 ± 0.2 to 63.0 ± 4.4 kJ·m−2. Mortality and behavior of the larvae were followed for 8–12 days, and growth measured at the end of the experiment. Also, the principle of reciprocity—that the UVR-induced mortality depends on the cumulative dose, independent of fluence rate—was tested. Fluence rates higher than 1480 ± 150 mW·m−2 caused mortality and growth retardation. The highest fluence rate (3040 ± 210 mW·m−2) caused 100% mortality in 5 days. All fluence rates caused behavioral disorde…
Biological responses of Rhynchophorous ferrugineus to Steirnenema carpocapase: an example of a model system
2011
Rhynchophorus ferrugineus (Coleoptera: Curculionidae) known as the Red Palm Weevil (RPW) is becoming more and more of a problem in Italy, and especially in Sicily, where it is well adapted. The infestations are mainly in the urban areas, and for that reason, chemical control is not advisable. Data from literature show that entomopathogenic nematodes (EPN) control RPW quite successfully in the field. However, results coming from the laboratories are often in contrast with each other and no data are available on precise doses. In this context we studied the Median Lethal Dose (DL50) and the Median Lethal Time (TL50) of young and older larvae and also of adults. The doses for the adults were t…
Responses of Rhynchophorus ferrugineus adults to selected synthetic palm esters: electroantennographic studies and trap catches in an urban environme…
2011
The Red Palm Weevil (RPW), Rhynchophorus ferrugineus Olivier, accidentally introduced in the European countries facing the Mediterranean basin, is becoming the most serious pest for ornamental palms in the urban environment. In our work we tested electroantennogram (EAG) and behavioural responses of RPW adults to five selected synthetic palm esters: ethyl propionate, ethyl butyrate, ethyl isobutyrate, ethyl lactate and ethyl acetate. EAG bioassays showed higher sensitivity of female antennae compared to male antennae for test compounds. Differences were also recorded in the EAG responses using different esters and doses. Ethyl propionate was the synthetic ester that elicited the strongest r…
Robustness of radiation beam profile measurements
2023
In this master’s thesis, profile measurements of PTW Semiflex 3D and PTW Semiflex ionisation chambers in addition to IBA MatriXX matrix detector were compared to each other using different measurement set-ups. The ionisation chamber measure- ments were done in a water phantom in horizontal and vertical orientations. Using two different set-ups in the horizontal orientation. The first horizontal set-up used the current clinical quality assurance program in Tampere University Hospital with the wire of the chamber lying deep in the water phantom. The second horizontal measurements were done with more of the wire in the radiation field by having the wire closer to the surface of the water. Meas…
HOW MUCH DANGEROUS IS CT ACCORDING TO PATIENTS AND HOW DOES DOSE BILL AFFECT THEIR PERCEPTION OF IONIZING RADIATION?
2015
Aims and objectives Methods and materials Results Conclusion Personal information References