Search results for "Calculation"
showing 10 items of 594 documents
Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements
2013
[EN] The "Neutrino Experiment with a Xenon Time-Projection Chamber" (NEXT) is intended to investigate the neutrinoless double beta decay of Xe-136, which requires a severe suppression of potential backgrounds. An extensive screening and material selection process is underway for NEXT since the control of the radiopurity levels of the materials to be used in the experimental set-up is a must for rare event searches. First measurements based on Glow Discharge Mass Spectrometry and gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterraneo de Canfranc (Spain) are described here. Activity results for natural radioactive chains and other common radionucl…
A novel 2,6-bis(benzoxazolyl)phenol macrocyclic chemosensor with enhanced fluorophore properties by photoinduced intramolecular proton transfer
2023
Macrocyclic ligand L, in which a 2,6-bis(2-benzoxazolyl)phenol (bis-HBO) group is incorporated in triethylenetetramine, was designed and synthesized with the aim of creating a chemosensor with high selectivity and specificity for metal cations in an aqueous environment. The availability of several proton acceptors and donors, and amine and phenol hydroxy groups, respectively, affects the keto-enol equilibrium in both the ground and excited states, and the ligand properties show dependence on the pH of the solution. L is fluorescent in the visible range, through an excited-state intramolecular proton transfer (ESIPT) mechanism. The results of an exhaustive characterization of L by spectrosco…
Akūta alkohola hepatīta klīniskā norise un iznākumi
2015
Diplomdarba tēma. Akūta alkohola hepatīta klīniskā norise un iznākumi. Ievads. Alkohola hepatīts ir klīnisks sindroms, ko izraisa hroniska alkohola lietošana. Akūts alkohola hepatīts vienmēr attīstās uz jau esoša hroniska alkohola aknu bojājuma fona – taukainās hepatozes, steatohepatīta, fibrozes vai cirozes. Agrīna mirstība no alkohola hepatīta variē pēc slimības smaguma no 20% vieglām formām līdz 30-60% smagām formām. Darba mērķis. Pacientiem ar akūtu alkohola hepatītu noteikt un salīdzināt prognostiskos rādītājus pēc Maddrey un MELD aprēķiniem, kas ļautu prognozēt slimības attīstības tendenci un iznākumu pirmreizēji stacionētiem, atkārtoti stacionētiem un mirušiem pacientiem Latvijā. Mat…
Solution structure of R2Sn(IV)-β-N-Acetyl-Neuraminate (R=Me, Bu) complexes in D2O and DMSO-d6: experimental NMR and DFT computational study.
2007
Two diorganotin(IV)-NANA complexes (NANA (1) = beta-N-acetyl-Neuraminic Acid = 5-amino-3,5-dideoxy-D-glycero-beta-D-galactononulosic acid) with formula Me(2)Sn(iv)NANA (2) and Bu(2)Sn(IV)NANA (3) were synthesized and characterized by (1)H, (13)C and (119)Sn NMR spectroscopy, both in D(2)O and DMSO-d(6) solutions. The experimental data in DMSO suggested the monosaccharide bidentate chelation via O1 carboxylate and vicinal O2 alkoxide atoms, which, in D(2)O, can be dynamically extended to a third binding site (O8 atom) of the pendant chain. Coordination at the tin atom is discussed on the basis of experimental NMR data and DFT calculation.
Coordination Complexes of a Neutral 1,2,4-Benzotriazinyl Radical Ligand: Synthesis, Molecular and Electronic Structures, andMagnetic Properties
2015
A series of d-block metal complexes of the recently reported coordinating neutral radical ligand 1-phenyl-3-(pyrid-2-yl)-1,4-dihydro-1,2,4-benzotriazin-4-yl (1) was synthesized. The investigated systems contain the benzotriazinyl radical 1 coordinated to a divalent metal cation, MnII, FeII, CoII, or NiII, with 1,1,1,5,5,5-hexafluoroacetylacetonato (hfac) as the auxiliary ligand of choice. The synthesized complexes were fully characterized by single-crystal X-ray diffraction, magnetic susceptibility measurements, and electronic structure calculations. The complexes [Mn(1)(hfac)2] and [Fe(1)(hfac)2] displayed antiferromagnetic coupling between the unpaired electrons of the ligand and the meta…
Magnetism and EPR spectra of the two‐sublattice manganese chain Mn2(EDTA)⋅9H2O
1990
We report on the magnetic behavior and single‐crystal EPR spectra of the chain complex Mn2(EDTA)⋅9H2O characterized by two different alternating sites for the manganese ions. Magnetic susceptibility data are indicative of weak antiferromagnetic exchange interactions between the manganese ions, showing a maximum of about 3 K. This behavior can be accurately described on the basis of a Heisenberg chain model that assumes classical spins, giving J/k=−0.72 K and g=2.0. The EPR spectra are typically low dimensional, with an angular dependence of the linewidth of the type (3 cos2 θ−1)n (n=4/3 or 2). Nevertheless, such a behavior cannot be reproduced from a one‐dimensional model with dipolar broad…
Working memory capacity does not always promote dual-task motor performance: The case of juggling in soccer.
2019
The aim of this research was to refine our understanding of the role of working memory capacity (WMC) on motor performances that require attentional control in dual-task situations. Three studies were carried out on soccer players. Each participant had to perform a juggling task in both normal and dual-task conditions. In Study 1, the interfering task was a mental calculation test performed under time pressure (strong cognitive load). In Study 2, the interfering task was a count-down test (low cognitive load). In Study 3 an intra-individual design in which participants perform dual-tasks increasingly complex has been proposed. Results showed a positive relationship between participants' WMC…
Model-Based Dose Calculation Algorithms for Brachytherapy Dosimetry
2019
The purpose of this study was to review the limitations of dose calculation formalisms for photon-emitting brachytherapy sources based on the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) report and to provide recommendations to transition to model-based dose calculation algorithms. Additionally, an overview of these algorithms and approaches is presented. The influence of tissue and seed/applicator heterogeneities on brachytherapy dose distributions for breast, gynecologic, head and neck, rectum, and prostate cancers as well as eye plaques and electronic brachytherapy treatments were investigated by comparing dose calculations based on the TG-43 formalism …
A simple analytical method for heterogeneity corrections in low dose rate prostate brachytherapy
2015
In low energy brachytherapy, the presence of tissue heterogeneities contributes significantly to the discrepancies observed between treatment plan and delivered dose. In this work, we present a simplified analytical dose calculation algorithm for heterogeneous tissue. We compare it with Monte Carlo computations and assess its suitability for integration in clinical treatment planning systems. The algorithm, named as RayStretch, is based on the classic equivalent path length method and TG-43 reference data. Analytical and Monte Carlo dose calculations using Penelope2008 are compared for a benchmark case: a prostate patient with calcifications. The results show a remarkable agreement between …
Tapentadol at medium to high doses in patients previously receiving strong opioids for the management of cancer pain.
2014
Abstract Abstract Objective: The aim of this study was to assess the efficacy and tolerability of tapentadol (TP) for a period of 4 weeks in patients who were already treated by opioids. Methods: A convenience sample of 30 patients was selected for a prospective observational cohort study. Cancer patients who were receiving at least 60 mg of oral morphine equivalents were selected. Patients discontinued their previous opioid analgesics before starting TP, in doses calculated according the previous opioid consumption (1:3.3 ratio with oral morphine equivalents). The subsequent doses were changed according to the patients' needs for a period of 4 weeks. Oral morphine was offered as a breakthr…