53 results on '"N. Blagojevic"'
Search Results
2. Towards a dynamic earthquake risk framework for Switzerland
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M. Böse, L. Danciu, A. Papadopoulos, J. Clinton, C. Cauzzi, I. Dallo, L. Mizrahi, T. Diehl, P. Bergamo, Y. Reuland, A. Fichtner, P. Roth, F. Haslinger, F. Massin, N. Valenzuela, N. Blagojević, L. Bodenmann, E. Chatzi, D. Fäh, F. Glueer, M. Han, L. Heiniger, P. Janusz, D. Jozinović, P. Kästli, F. Lanza, T. Lee, P. Martakis, M. Marti, M.-A. Meier, B. Mena Cabrera, M. Mesimeri, A. Obermann, P. Sanchez-Pastor, L. Scarabello, N. Schmid, A. Shynkarenko, B. Stojadinović, D. Giardini, and S. Wiemer
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Environmental technology. Sanitary engineering ,TD1-1066 ,Geography. Anthropology. Recreation ,Environmental sciences ,GE1-350 ,Geology ,QE1-996.5 - Abstract
Scientists from different disciplines at ETH Zurich are developing a dynamic, harmonised, and user-centred earthquake risk framework for Switzerland, relying on a continuously evolving earthquake catalogue generated by the Swiss Seismological Service (SED) using the national seismic networks. This framework uses all available information to assess seismic risk at various stages and facilitates widespread dissemination and communication of the resulting information. Earthquake risk products and services include operational earthquake (loss) forecasting (OE(L)F), earthquake early warning (EEW), ShakeMaps, rapid impact assessment (RIA), structural health monitoring (SHM), and recovery and rebuilding efforts (RRE). Standardisation of products and workflows across various applications is essential for achieving broad adoption, universal recognition, and maximum synergies. In the Swiss dynamic earthquake risk framework, the harmonisation of products into seamless solutions that access the same databases, workflows, and software is a crucial component. A user-centred approach utilising quantitative and qualitative social science tools like online surveys and focus groups is a significant innovation featured in all products and services. Here we report on the key considerations and developments of the framework and its components. This paper may serve as a reference guide for other countries wishing to establish similar services for seismic risk reduction.
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- 2024
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3. Comparing results of X-ray diffraction, µ-Raman spectroscopy and neutron diffraction when identifying chemical phases in seized nuclear material, during a comparative nuclear forensics exercise
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Emma Young, Fabien Pointurier, Linnea Ahlinder, Tshepo Ntsoane, James R. Hester, Gordon J. Thorogood, N. Blagojevic, Aubrey N. Nelwamondo, Kiel Holliday, Sarah Roberts, Stina Holmgren Rondahl, François Delaunay, Henrik Ramebäck, Olivier Marie, and Brice Ravat
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Diffraction ,Materials science ,XRD ,Health, Toxicology and Mutagenesis ,Nuclear forensics ,Neutron diffraction ,Analytical chemistry ,Context (language use) ,02 engineering and technology ,Nuclear material ,010403 inorganic & nuclear chemistry ,01 natural sciences ,Article ,Analytical Chemistry ,symbols.namesake ,Radiology, Nuclear Medicine and imaging ,Spectroscopy ,Public Health, Environmental and Occupational Health ,Uranium oxide ,021001 nanoscience & nanotechnology ,Pollution ,Phase identification ,0104 chemical sciences ,Nuclear Energy and Engineering ,X-ray crystallography ,symbols ,µ-Raman Spectroscopy ,0210 nano-technology ,Raman spectroscopy - Abstract
This work presents the results for identification of chemical phases obtained by several laboratories as a part of an international nuclear forensic round-robin exercise. In this work powder X-ray diffraction (p-XRD) is regarded as the reference technique. Neutron diffraction produced a superior high-angle diffraction pattern relative to p-XRD. Requiring only small amounts of sample, µ-Raman spectroscopy was used for the first time in this context as a potentially complementary technique to p-XRD. The chemical phases were identified as pure UO2 in two materials, and as a mixture of UO2, U3O8 and an intermediate species U3O7 in the third material. Electronic supplementary material The online version of this article (10.1007/s10967-017-5666-3) contains supplementary material, which is available to authorized users.
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- 2018
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4. Structural changes in a commercial lithium-ion battery during electrochemical cycling: An in situ neutron diffraction study
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M.M. Elcombe, N. Blagojevic, Maxim Avdeev, Andrew J Studer, Rozila Yusoff, Norlida Kamarulzaman, Neeraj Sharma, and Vanessa K. Peterson
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Battery (electricity) ,Materials science ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,Energy Engineering and Power Technology ,Electrochemistry ,Lithium battery ,Cathode ,Lithium-ion battery ,law.invention ,Anode ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,law ,Graphite ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Lithium cobalt oxide - Abstract
The structural response to electrochemical cycling of the components within a commercial Li-ion battery (LiCoO2 cathode, graphite anode) is shown through in situ neutron diffraction. Lithuim insertion and extraction is observed in both the cathode and anode. In particular, reversible Li incorporation into both layered and spinel-type LiCoO2 phases that comprise the cathode is shown and each of these components features several phase transitions attributed to Li content and correlated with the state-of-charge of the battery. At the anode, a constant cell voltage correlates with a stable lithiated graphite phase. Transformation to de-lithiated graphite at the discharged state is characterised by a sharp decrease in both structural cell parameters and cell voltage. In the charged state, a two-phase region exists and is composed of the lithiated graphite phase and about 64% LiC6. It is postulated that trapping Li in the solid|electrolyte interface layer results in minimal structural changes to the lithiated graphite anode across the constant cell voltage regions of the electrochemical cycle.
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- 2010
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5. Investigation of cell parameters, microstructures and electrochemical behaviour of LiMn2O4 normal and nano powders
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M.M. Elcombe, Abdul Kariem Arof, MG Blackford, M. A. Bustam, Norazuwana Shaari, Norashikin Kamarudin, N. Blagojevic, Raja Mohamad Fairuz R. Mohamad Yusoff, N.A. Abdul Aziz, Norlida Kamarulzaman, and Maxim Avdeev
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Materials science ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Mineralogy ,Microstructure ,Electrochemical cell ,Chemical engineering ,Nano ,Crystallite ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Cyclic voltammetry ,Ball mill ,Powder diffraction ,Sol-gel - Abstract
Nano materials are usually difficult to prepare. This work presents a simple way of preparing LiMn 2 O 4 nano powders using the high-energy ball milling method. This method has the advantage of producing pure, single-phase and crystalline nano powders. The milling method is carefully controlled to avoid unwanted chemical reactions that may change the stoichiometry of the material. Nano powders of between 30 and 50 nm are obtained. Structural studies of the nano powders, as well as the more conventional micron-sized LiMn 2 O 4 , are made using X-ray diffraction and neutron diffraction methods. Electrochemical evaluation of the materials is undertaken with a three-probe cyclic voltammetry technique and galvanostatic charge–discharge measurements. Structural studies reveal that not only are the crystallites of the nano powders much reduced in size from the normal powders, but their cell parameters are also smaller. The performance characteristics of the nano material show an improvement over that of the micron-sized material by about 17% in the 1st cycle and 70.6% in the 5th cycle, at which the capacity is 132 mAh g −1 . The normal material suffers from severe capacity fading but the nano material shows much improved capacity retention.
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- 2009
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6. Non-isothermal crystallization of K2O·TiO2·3GeO2 glass
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Vladimir D. Živanović, Snežana R. Grujić, N. Blagojevic, Jelena Nikolić, and M.B. Tošić
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Range (particle radiation) ,Morphology (linguistics) ,Chemistry ,Isothermal crystallization ,Analytical chemistry ,Mineralogy ,Crystal growth ,02 engineering and technology ,Activation energy ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,010406 physical chemistry ,0104 chemical sciences ,law.invention ,Volume (thermodynamics) ,law ,Particle ,Physical and Theoretical Chemistry ,Crystallization ,0210 nano-technology - Abstract
The crystallization of K2O·TiO2·3GeO2 glass under non-isothermal condition was studied. In powdered glass with particle sizes less than 0.15 mm, surface crystallization was dominant and an activation energy of crystal growth of Ea,s=327±50 kJ mol−1 was calculated. In the size range 0.15 to 0.45 mm, both surface and volume crystallization occurred. For particle sizes >0.45 mm, volume crystallization dominated with spherulitic morphology of the crystals growth and Ea,v=359±64 kJ mol−1 was calculated.
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- 2009
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7. The effect of TiO2 on the structure and devitrification behavior of potassium titanium germanate glass
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B Božović, Vladimir D. Živanović, M.B. Tošić, N. Blagojevic, and Snežana R. Grujić
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Fourier transform infrared spectroscopy (FTIR) ,Glasses ,Potassium ,Analytical chemistry ,chemistry.chemical_element ,Differential thermal analysis (DTA) ,Condensed Matter Physics ,law.invention ,Devitrification ,chemistry ,law ,Differential thermal analysis ,Germanate ,Physical and Theoretical Chemistry ,Crystallization ,Thermal analysis ,Glass transition ,Titanium - Abstract
The effect of replacing 20 mol% of GeO 2 by TiO 2 on the properties of potassium germanate glass was investigated. The structure and devitrification behaviour of glasses were studied by Fourier transform infrared spectroscopy (FTIR), differential thermal analysis (DTA) and X-ray diffraction (XRD). It was observed that potassium titanium germanate has a higher glass transition temperature and a higher thermal stability vs. crystallization. The presence of two exothermic peaks on the DTA curve of potassium germanate glass indicates the complex crystallization process. The XRD pattern of this glass heated at the temperature of the first crystallization peak indicated that the GeO 2 and K 2 Ge 7 O 15 were formed. Only the K 2 TiGe 3 O 9 phase was identified, in a case when potassium titanium germanate glass was heated at the temperature of the crystallization peak.
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- 2006
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8. Investigation of titanium corrosion in concentrated NaOH solutions
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N. Blagojevic, J.M. Pjescic, and Slavko Mentus
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Mechanical Engineering ,Inorganic chemistry ,Metals and Alloys ,Oxide ,chemistry.chemical_element ,General Medicine ,Electrolyte ,Surfaces, Coatings and Films ,Anode ,Corrosion ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Electrode ,Materials Chemistry ,Environmental Chemistry ,Cyclic voltammetry ,Polarization (electrochemistry) ,Titanium - Abstract
The rate of both spontaneous and polarization assisted formation of oxide films on commercially grade titanium, DIN 3.7025, was studied in concentrated, 1 - 5M NaOH solutions, with particular attention to the early stages of oxide formation. Simultaneous chemical dissolution of oxides was considered. The rate of spontaneous oxide formation was examined with cyclic voltammetry as an in-situ method. The shape of potentiodynamic curves recorded in different alkaline solutions indicated that the electrolyte concentration affects the oxide composition. Titanium electrodes were covered with oxide films of different thickness, and the time dependence of polarization resistance was measured under a fixed anodic polarization. The polarization resistance may either increase or decrease tending to attain a stationary value, which, for a fixed polarization, depends on both the initial thickness and the NaOH concentration. (orig.)
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- 2002
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9. Grazing incidence X-ray fluorescence study of the surface leaching behaviour of synroc
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R. F. Garrett and N. Blagojevic
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Physics ,Nuclear and High Energy Physics ,Beamline ,law ,Grazing ,Analytical chemistry ,X-ray fluorescence ,Leaching (metallurgy) ,Synroc ,Instrumentation ,law.invention ,Bending magnets - Abstract
A pilot study has been performed into the suitability of grazing incidence X-ray fluorescence analysis for determining leaching profiles in synroc. It is shown that dilute components can be easily measured on a bending magnet beamline, and concentration depth profiles resulting from leaching can be detected. In combination with simplified model leaching profiles, some quantitative information on leach depth can be obtained.
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- 2001
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10. Crystallization kinetics of K2O·TiO2· 3GeO2 glass studied by DTA
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V. Živanovic, Snežana R. Grujić, M.B. Tošić, Jelena Nikolić, and N. Blagojevic
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Diffraction ,Materials science ,Metals and Alloys ,Analytical chemistry ,Mineralogy ,Crystal growth ,Activation energy ,Atmospheric temperature range ,Crystallization kinetics ,Condensed Matter Physics ,Kinetic energy ,lcsh:Chemical technology ,law.invention ,law ,Differential thermal analysis ,Materials Chemistry ,Ceramics and Composites ,Polymorphic crystallization ,lcsh:TP1-1185 ,Particle size ,Crystallization ,Germanate glass - Abstract
Crystallization kinetics of K2O?TiO2?3GeO2 glass was investigated by differential thermal analysis (DTA). Experiments were performed on powder samples with a particle size < 0.037 mm. The glass samples were heated at different rates in the temperature range 20-750?C. The kinetic parameters, activation energy for the crystallization process, Ec and Avrami exponent, n were calculated. Powder X-ray diffraction analysis (XRD) of crystallized glass reveals the presence of crystalline K2O?TiO2?3GeO2 indicating polymorphic crystallization with interface controlled crystal growth.
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- 2008
11. Immobilisation of Contaminated DEHPA Waste in Portland Cement
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Syed A. Malik, N. Blagojevic, Laurie P. Aldridge, and Lou Vance
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Cement ,Materials science ,Metallurgy ,Contamination ,law.invention ,chemistry.chemical_compound ,Portland cement ,chemistry ,law ,Monazite ,Leaching (metallurgy) ,Solvent extraction ,Porosity ,Phosphoric acid - Abstract
The immobilisation of organic liquids in cement products can often be difficult when attempts are made to achieve high waste loading. In this work, diethylhexyl phosphoric acid (DEHPA) contaminated with minor amounts of U (1400 ppm), Th (100 ppm) and rare earth elements (17,900 ppm) arising from solvent extraction technology for rare earth extraction from monazite shows promise of immobilisation in ordinary Portland cement (OPC). Waste loadings of up to 50% (v/v) have been achieved at the laboratory scale. The product was allowed to set overnight and had reasonable resistance to leaching after exposure to deionised water (DIW) at 25°C. Centimetre-sized samples released
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- 2003
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12. CHANGES IN BODY PROTEIN COMPOSITION FOLLOWING AORTIC RECONSTRUCTION
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John P. Fletcher, N. Blagojevic, and Barry J. Allen
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medicine.medical_specialty ,Aorta ,Nitrogen balance ,business.industry ,Urology ,chemistry.chemical_element ,General Medicine ,Protein composition ,Aortic surgery ,Nitrogen ,Fight-or-flight response ,Excretion ,chemistry ,medicine.artery ,Internal medicine ,medicine ,Cardiology ,Surgery ,business ,Nitrogen cycle - Abstract
Major surgery initiates a stress response due to the body's neuroendocrine reaction which leads to a breakdown of muscle protein with an increased urinary nitrogen excretion and a negative nitrogen balance. In vivo neutron activation analysis (IVNAA) is a technique which measures total body nitrogen. A total of 23 IVNAA studies were performed in six patients having aortic reconstruction to assess the effect of this major operation on body nitrogen and to determine the time required for a return to the pre-operative state. Aortic surgery caused a mean decrease of 2.9% in bodyweight (from a mean of 65.4 kg to 63.5 kg) but a much greater decrease of 9.9% in total body nitrogen (from a mean of 1778 g to 1602 g). Only two of six patients had recovered to pre-operative values by the end of the study period which extended for a mean of 92 days.
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- 1990
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13. Alpha- and beta-emitting radiolanthanides in targeted cancer therapy: the potential role of terbium-149
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B J Allen and N Blagojevic
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medicine.medical_treatment ,Alpha (ethology) ,Neoplasms ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Neoplasm Metastasis ,Beta (finance) ,Terbium ,Neoplasm Staging ,Radioisotopes ,Range (particle radiation) ,Neovascularization, Pathologic ,business.industry ,Chemistry ,Cancer ,General Medicine ,Alpha particle ,medicine.disease ,Alpha Particles ,Beta Particles ,Radiation therapy ,Lymphatic Metastasis ,Cancer cell ,Cancer research ,Metals, Rare Earth ,Drug carrier ,Nuclear medicine ,business - Abstract
The efficacy of systemic cancer therapy rests on the ability of a toxin to be preferentially located in cancer cells, so that cancer cell kill is maximized and normal tissue spared. This requires that the lifetime of the toxin be less than the lifetime of the carrier in the body, effectively ruling out chemical toxins, as they remain effective until excreted from the body. The requirement of localization of dose to the cancer cell makes radioactive beta-emitting radionuclides unattractive. Alpha-emitting radionuclides are much more appropriate toxins, as their efficacy depends on the high energy and short range of the alpha particles, and terbium-149 is shown to be the most efficacious of these. However, the merit of various alpha- and beta-emitting radionuclides depends on the stage and type of cancer. Recommendations are made with respect to the matching of the target cancer with required properties of the radiolabel and carrier.
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- 1996
14. Total body protein status of males infected with the human immunodeficiency virus
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C J, Oliver, A, Rose, N, Blagojevic, R, Dwyer, J, Gold, and B J, Allen
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Adult ,Male ,Time Factors ,Nitrogen ,Proteins ,HIV Infections ,Neutron Activation Analysis ,Middle Aged ,Nutrition Disorders ,Body Water ,Weight Loss ,Body Composition ,Electric Impedance ,Humans - Published
- 1993
15. Performance of the bismuth germanate total body chlorine analyzer
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N, Blagojevic, B J, Allen, and J, Russell
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Models, Structural ,Anorexia Nervosa ,Evaluation Studies as Topic ,Germanium ,Body Composition ,Humans ,Neutron Activation Analysis ,Chlorine ,Extracellular Space ,Bismuth ,Whole-Body Counting ,Hydrogen - Published
- 1993
16. Performance of the Bismuth Germanate Total Body Chlorine Analyzer
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Janice Russell, N. Blagojevic, and Barry J. Allen
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Heavy water ,chemistry.chemical_compound ,Spectrum analyzer ,chemistry ,Body water ,Radiochemistry ,polycyclic compounds ,Lean body mass ,Chlorine ,chemistry.chemical_element ,Total body ,Bismuth germanate ,Neutron activation - Abstract
The initial method for in-vivo determination of body chlorine (BC1) was total body neutron activation followed by whole body counting of activated chlorine1. Efforts to analyze total body chlorine (TBC1) using prompt-gamma/NaI system were successful, but the background in the chlorine region of interest 5 to 7 MeV was high and therefore the precision suffered2.
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- 1993
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17. Total Body Protein Status of Males Infected with the Human Immunodeficiency Virus
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Robyn Dwyer, Julian Gold, Alex Rose, Christopher J. Oliver, Barry J. Allen, and N. Blagojevic
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business.industry ,Body water ,Physiology ,medicine.disease ,Virology ,Asymptomatic ,Malnutrition ,Weight loss ,Extracellular fluid ,Lean body mass ,medicine ,medicine.symptom ,business ,Wasting ,Bioelectrical impedance analysis - Abstract
Weight loss and wasting are cardinal signs of malnutrition in advanced human immunodeficiency virus (HIV) infection. Kotler et al1 observed a disproportionate depletion of the body cell mass relative to body weight (i.e. 68 ± 10% vs 82 ± 10%) along with a relative expansion of the extracellular fluid volume and concluded that the pattern of weight loss was more like a stressed or injured state than one of starvation. The same researchers also observed that the decline in body cell mass in HIV was predictive of mortality2. There are very few longitudinal data on body composition in HIV, particularly in the asymptomatic phase, even though wasting can precede the onset of opportunistic infections. It seemed important to study body composition in the ‘asymptomatic’ phase of HIV to discover the extent and type of changes, if any, that were occurring. These findings may be clinically important in terms of the early implementation of nutritional support and anti-viral therapy. This study used in vivo prompt gamma neutron activation analysis to measure total body nitrogen as a measure of body cell mass, and compared the total body nitrogen levels in asymptomatic HIV-positive persons both over time and against HIV-positive persons with profound weight loss.
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- 1993
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18. A total body nitrogen facility for paediatric use
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A. Rose, K.J. Gaskin, Allen Bj, Louise A. Baur, and N. Blagojevic
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Neutrons ,Total body nitrogen ,Materials science ,Supine position ,Radiological and Ultrasound Technology ,Fission ,business.industry ,Nitrogen ,Gamma ray ,Australia ,Neutron radiation ,Protein-Energy Malnutrition ,Collimated light ,Neutron capture ,Facility Design and Construction ,Calibration ,Humans ,Radiology, Nuclear Medicine and imaging ,Nuclear medicine ,business ,Child - Abstract
The design, calibration and evaluation of a facility for in vivo prompt gamma neutron capture analysis of total body nitrogen in children is described. The patient is scanned in both supine and prone positions, across a vertically collimated beam from a 1 GBq 252Cf fission source. Two NaI(T1) detectors are placed on either side of the patient, perpendicular to both the neutron beam and the scanning direction. The effective dose equivalent delivered to a child during an 840 s scan is approximately 0.14 mSv (QF = 10). Correction factors for nitrogen background (width-dependent), hydrogen background (1-4% of hydrogen gamma ray peak) and the differential attenuation of nitrogen and hydrogen gamma rays (width-dependent) can be applied to the measured nitrogen-to-hydrogen gamma ray counts ratio. By using the mass of hydrogen (based on body mass and fat mass) as an internal standard, the nitrogen mass can then be determined. Measurements with a urea-containing box phantom show that the current precision (CV) of the net nitrogen counts and of the nitrogen-to-hydrogen counts ratio is +/- 2.0% and +/- 1.5%, respectively. Using small anthropomorphic and other phantoms, estimation of the mass of nitrogen has a precision of +/- 1.4 to 5.4% and an accuracy of 97.1 to 101.5%.
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- 1991
19. Determination of total body water by Fourier transform infrared analysis
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N, Blagojevic, B J, Allen, K J, Gaskin, and L A, Baur
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Adult ,Male ,Body Water ,Fourier Analysis ,Infrared Rays ,Nitrogen ,Reference Values ,Potassium ,Humans ,Reproducibility of Results ,Female ,Middle Aged ,Deuterium - Abstract
A new technique for determining body water using deuterium isotope dilution and Fourier transform infrared (FTIR) analysis is described. The advantages of the FTIR over conventional dispersion and filter infrared instruments include greater flexibility through computer controlled operations and availability of 'on-line' analytical software. The technique was further improved by the development of a simple procedure for determining D2O concentration in untreated serum samples. A validation study of six normal adults showed that the fat-free-mass determined from the deuterium-space (total body water) correlated well with the results obtained by total body nitrogen (r = 0.997), total body potassium (r = 0.996) and anthropometric (r = 0.995) measurements.
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- 1990
20. Changes in body protein composition following aortic reconstruction
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J P, Fletcher, B J, Allen, and N, Blagojevic
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Male ,Time Factors ,Nitrogen ,Body Weight ,Aortic Diseases ,Proteins ,Neutron Activation Analysis ,Middle Aged ,Postoperative Complications ,Body Composition ,Body Constitution ,Humans ,Female ,Aorta ,Aged - Abstract
Major surgery initiates a stress response due to the body's neuroendocrine reaction which leads to a breakdown of muscle protein with an increased urinary nitrogen excretion and a negative nitrogen balance. In vivo neutron activation analysis (IVNAA) is a technique which measures total body nitrogen. A total of 23 IVNAA studies were performed in six patients having aortic reconstruction to assess the effect of this major operation on body nitrogen and to determine the time required for a return to the pre-operative state. Aortic surgery caused a mean decrease of 2.9% in bodyweight (from a mean of 65.4 kg to 63.5 kg) but a much greater decrease of 9.9% in total body nitrogen (from a mean of 1778 g to 1602 g). Only two of six patients had recovered to pre-operative values by the end of the study period which extended for a mean of 92 days.
- Published
- 1990
21. The Role of Body Protein Studies in Clinical Trials
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G. Ambler, M. A. Allman, Kevin J. Gaskin, Barry J. Allen, J. P. Fletcher, David J. Tiller, Donna Waters, Christopher T. Cowell, N. Blagojevic, Carol A. Pollock, I. Delaney, Louise A. Baur, C. Quigley, and Lloyd S. Ibels
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medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Continuous ambulatory peritoneal dialysis ,food and beverages ,nutritional and metabolic diseases ,Total body ,Growth hormone ,Gastroenterology ,digestive system diseases ,Peritoneal dialysis ,Clinical trial ,Internal medicine ,medicine ,business - Abstract
Short-term protein accrection in malnourished patients does not necessarily equate to a long-term gain in total body protein.
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- 1990
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22. The role of body protein studies in clinical trials
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B J, Allen, N, Blagojevic, I, Delaney, C A, Pollock, L S, Ibels, M A, Allman, D J, Tiller, K J, Gaskin, L A, Baur, and D L, Waters
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Adult ,Male ,Clinical Trials as Topic ,Adolescent ,Anthropometry ,Cystic Fibrosis ,Nitrogen ,Proteins ,Prognosis ,Nutrition Disorders ,Peritoneal Dialysis, Continuous Ambulatory ,Reference Values ,Body Composition ,Humans ,Kidney Failure, Chronic ,Female ,Longitudinal Studies ,Child ,Vascular Surgical Procedures ,Aorta ,Retrospective Studies - Published
- 1990
23. Body Composition in Cystic Fibrosis
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D. Parsons, Allen Bj, Donna Waters, N. Blagojevic, Louise A. Baur, V. L. Soutter, and K.J. Gaskin
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Pediatrics ,medicine.medical_specialty ,Lung ,business.industry ,Anorexia ,medicine.disease ,Sick child ,Cystic fibrosis ,Liver disease ,Malnutrition ,medicine.anatomical_structure ,medicine ,medicine.symptom ,business ,Nutritional rehabilitation ,Wasting - Abstract
Over the last two decades there has been an increasing interest in the nutritional problems of patients with cystic fibrosis (CF). This situation has arisen from reports (Yassa et al., 1978; Soutter et al., 1986) indicating that stunting and wasting are common, and contrasting reports from the Hospital for Sick Children, Toronto, cystic fibrosis clinic (Corey, 1980; Corey et al., 1984), demonstrating that their patients conform to the normal distribution for height and, to a lesser extent, weight percentiles. Moreover, the Maintenance of normal nutritional status and growth may have considerably enhanced the prognosis of patients at the Toronto clinic (Corey, 1980) in comparison to other clinics. Consequently, a number of studies have been performed to define the origin of CF malnutrition, its deleterious effect on body composition, growth and lung function, and the possible benefits of nutritional rehabilitation programs. Dietary intake analyses have revealed that most CF patients consume large amounts of protein similar to controls (Soutter et al., 1986). In contrast, due to the almost universal policy of the provision of a low fat diet, a persistent energy deficit has occurred (Roy et al., 1984). The latter has been compounded by the effects of anorexia due to lung, gut and liver disease and drug administration, and possibly excessive energy expenditure related to lung disease, recurrent lung infections and the underlying disease process.
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- 1990
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24. Development of a total body chlorine analyser using a bismuth germanate detector system and a 252Cf neutron source
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N, Blagojevic, B J, Allen, and A, Rose
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Neutrons ,Oxygen ,Germanium ,Body Composition ,Humans ,Scattering, Radiation ,Neutron Activation Analysis ,Chlorine ,Bismuth - Published
- 1990
25. Development of a Total Body Chlorine Analyser Using a Bismuth Germanate Detector System and a 252Cf Neutron Source
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A. Rose, Barry J. Allen, and N. Blagojevic
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chemistry ,Isotope ,Activation product ,Radiochemistry ,Chlorine ,chemistry.chemical_element ,Neutron source ,Neutron ,Neutron activation analysis ,Particle detector ,Neutron activation - Abstract
The initial method for in vivo determination of total body chlorine (TBCl) was total body neutron activation followed by whole body counting of residual products. The technique relied on the exposure of the subject to a sufficient fluence of neutrons to activate body sodium and chlorine. Subsequently, 38Cl and 24Na were quantified and correlated to the extracellular water (ECW) previously determined by tracer dilution analysis (Yasumura et al., 1983). The najor drawbacks of this technique are the following: a) the radiation exposure during the activation process is approximately 280 mrem (2.8 mSv); b) the method is time consuming as it consists of two separate operations, namely activation and a counting step; c) the unit cost is high because it requires two separate facilities and a number of high flux neutron sources; and d) the patient must be quickly moved iron one facility into another to be counted as 38Cl, the chlorine activation product, which has a half-life of only 37.3 minutes.
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- 1990
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26. In vivo determination of protein by prompt neutron capture in fibrocystic disease
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N. Blagojevic, V. L. Soutter, K. Gaskin, B. J. Allen, and R. Howman‐Giles
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Physics ,Nuclear reaction ,Total body nitrogen ,Prompt neutron ,In vivo ,business.industry ,Radiochemistry ,Neutron source ,Dose distribution ,Muscle mass ,Nuclear medicine ,business ,Fibrocystic disease - Abstract
Measurements of total body nitrogen (TBN) and muscle mass is a useful tool in assessing nutritional repletion of malnourished subjects. The present study examines a prototype facility for measuring TBN by prompt neutron activation with a Pu‐Be or 252Cf fast neutron source and observing the 10.8 MeV ground state γ‐ray from the 14N(N,γ) reaction with NaI detectors. Dose distributions, background sensitivity and nitrogen yields are reported for phantoms and a maximum radiation dose of 20 mrem per exposure is determined. We proposed to measure TBN and muscle mass in a group of malnourished patients before and during nutritional repletion.
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- 1985
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27. The extraction of fission product molybdenum-99 by dithiol precipitation
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E.L.R. Hetherington, N. Blagojevic, and R.E. Boyd
- Subjects
Fission products ,Nuclear fission product ,Radiation ,Precipitation (chemistry) ,Extraction (chemistry) ,Radiochemistry ,Isotopes of molybdenum ,Dithiol ,chemistry.chemical_element ,Fission product yield ,chemistry.chemical_compound ,Nuclear Energy and Engineering ,chemistry ,Molybdenum ,Radiology, Nuclear Medicine and imaging ,Nuclear chemistry - Abstract
A method has been developed for the preliminary extraction of fission product molybdenum-99 from irradiated UO 2 . The method uses toluene-3,4-dithiol to precipitate carrier-free molybdenum from fission products dissolved in HNO 3 . The extraction efficiency is greater than 90% and the radionuclidic purity is approximately 97%.
- Published
- 1985
- Full Text
- View/download PDF
28. Holmium-166m sources for energy and e efficiency calibration of γ-spectrometry systems
- Author
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N.R. Wood and N. Blagojevic
- Subjects
Range (particle radiation) ,Radiation ,Materials science ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Analytical chemistry ,chemistry.chemical_element ,Mass spectrometry ,Efficiency ,Nuclear Energy and Engineering ,chemistry ,Calibration ,Radiology, Nuclear Medicine and imaging ,Holmium ,Energy (signal processing) - Abstract
A holmium-166m source for use in the energy and relative efficiency calibration of Ge (Li) detectors is described. The useful energy range of the source is between 80 keV and 1427 keV and the relative efficiency calibration range is between 80 and 951 keV.
- Published
- 1982
- Full Text
- View/download PDF
29. Multichannel analyser interface to an 8 bit microcomputer system
- Author
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N. Blagojevic and D.J. Reid
- Subjects
Radiation ,business.industry ,Computer science ,Interface (computing) ,Microcomputer system ,Analyser ,8-bit ,Software ,Nuclear Energy and Engineering ,Interfacing ,Radiology, Nuclear Medicine and imaging ,Spectral data ,business ,Computer hardware - Abstract
A practical method of interfacing a multichannel analyser (MCA) to an 8 bit microcomputer system is reported. The MCA does not require hardware modifications or a computer interface option. A device driver was written and incorporated in the operating system to enable the transmitted spectral data to be read and processed. The hardware and the software interface are described.
- Published
- 1985
- Full Text
- View/download PDF
30. Toward Predicting the Formation of Integral-Asymmetric, Isoporous Diblock Copolymer Membranes.
- Author
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Blagojevic N, Das S, Xie J, Dreyer O, Radjabian M, Held M, Abetz V, and Müller M
- Abstract
The self-assembly and nonsolvent-induced phase separation (SNIPS) process of block copolymers and solvents enables the fabrication of integral-asymmetric, isoporous membranes. An isoporous top layer is formed by evaporation-induced self-assembly (EISA) and imparts selectivity for ultrafiltration of functional macromolecules or water purification. This selective layer is supported by a macroporous bottom structure that is formed by nonsolvent-induced phase separation (NIPS) providing mechanical stability. Thereby the permeability/selectivity tradeoff is optimized. The SNIPS fabrication involves various physical phenomena-e.g., evaporation, self-assembly, macrophase separation, vitrification - and multiple structural, thermodynamic, kinetic, and process parameters. Optimizing membrane properties and rationally designing fabrication processes is a challenge which particle simulation can significantly contribute to. Using large-scale particle simulations, it is observed that 1) a small incompatibility between matrix-forming block of the copolymer and nonsolvent, 2) a glassy arrest that occurs at a smaller polymer concentration, or 3) a higher dynamical contrast between polymer and solvent results in a finer, spongy substructure, whereas the opposite parameter choice gives rise to larger macropores with an elongated shape. These observations are confirmed by comparison to experiments on polystyrene (PS)-block-poly(4-vinylpyridine) (P4VP) diblock copolymer membranes, varying the chemical nature of the coagulant or the temperature of coagulation bath., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)
- Published
- 2024
- Full Text
- View/download PDF
31. Correction to "Simulation of Membrane Fabrication via Solvent Evaporation and Nonsolvent-Induced Phase Separation".
- Author
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Blagojevic N and Müller M
- Published
- 2024
- Full Text
- View/download PDF
32. Simulation of Membrane Fabrication via Solvent Evaporation and Nonsolvent-Induced Phase Separation.
- Author
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Blagojevic N and Müller M
- Abstract
Block copolymer membranes offer a bottom-up approach to form isoporous membranes that are useful for ultrafiltration of functional macromolecules, colloids, and water purification. The fabrication of isoporous block copolymer membranes from a mixed film of an asymmetric block copolymer and two solvents involves two stages: First, the volatile solvent evaporates, creating a polymer skin, in which the block copolymer self-assembles into a top layer, comprised of perpendicularly oriented cylinders, via evaporation-induced self-assembly (EISA). This top layer imparts selectivity onto the membrane. Subsequently, the film is brought into contact with a nonsolvent, and the exchange between the remaining nonvolatile solvent and nonsolvent through the self-assembled top layer results in nonsolvent-induced phase separation (NIPS). Thereby, a macroporous support for the functional top layer that imparts mechanical stability onto the system without significantly affecting permeability is fabricated. We use a single, particle-based simulation technique to investigate the sequence of both processes, EISA and NIPS. The simulations identify a process window, which allows for the successful in silico fabrication of integral-asymmetric, isoporous diblock copolymer membranes, and provide direct insights into the spatiotemporal structure formation and arrest. The role of the different thermodynamic (e.g., solvent selectivity for the block copolymer components) and kinetic (e.g., plasticizing effect of the solvent) characteristics is discussed.
- Published
- 2023
- Full Text
- View/download PDF
33. Autoimmune Encephalitis and Autism Spectrum Disorder.
- Author
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Whiteley P, Marlow B, Kapoor RR, Blagojevic-Stokic N, and Sala R
- Abstract
The concept of "acquired autism" refers to the hypothesis that amongst the massive heterogeneity that encompasses autism spectrum disorder (ASD) there may be several phenotypes that are neither syndromic nor innate. Strong and consistent evidence has linked exposure to various pharmacological and infective agents with an elevated risk of a diagnosis of ASD including maternal valproate use, rubella and herpes encephalitis. Autoimmune encephalitis (AE) describes a group of conditions characterised by the body's immune system mounting an attack on healthy brain cells causing brain inflammation. The resultant cognitive, psychiatric and neurological symptoms that follow AE have also included ASD or autism-like traits and states. We review the current literature on AE and ASD. Drawing also on associated literature on autoimmune psychosis (AP) and preliminary evidence of a psychosis-linked subtype of ASD, we conclude that AE may either act as a potentially causative agent for ASD, and/or produce symptoms that could easily be mistaken for or misdiagnosed as autism. Further studies are required to discern the connection between AE and autism. Where autism is accompanied by regression and atypical onset patterns, it may be prudent to investigate whether a differential diagnosis of AE would be more appropriate., Competing Interests: RS has been an advisor to and has received honoraria from Takeda. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Whiteley, Marlow, Kapoor, Blagojevic-Stokic and Sala.)
- Published
- 2021
- Full Text
- View/download PDF
34. Blood-pressure variability is associated with left-ventricular mechanics in patients with gestational hypertension and preeclampsia.
- Author
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Tadic M, Cuspidi C, Suzic-Lazic J, Vukomanovic V, Mihajlovic S, Savic P, Blagojevic N, Grassi G, and Celic V
- Subjects
- Blood Pressure, Blood Pressure Monitoring, Ambulatory, Cross-Sectional Studies, Female, Humans, Pregnancy, Hypertension, Hypertension, Pregnancy-Induced diagnostic imaging, Pre-Eclampsia diagnostic imaging
- Abstract
We aimed to investigate short- and long-term blood-pressure (BP) variability and left-ventricular (LV) structure, function, and mechanics in women with gestational hypertension and preeclampsia, as well as the relationship between BP variability and LV mechanics. This cross-sectional study included 140 pregnant women (45 normotensive controls, 50 patients with gestational hypertension and, 45 patients with preeclampsia) after 20 weeks of gestation. All participants underwent 24-h ambulatory BP monitoring and echocardiographic examination, as well as regular clinical BP measurements during each visit. Our results show that 24-h, daytime and nighttime systolic and diastolic BP, as well as visit-to-visit systolic and diastolic BPs, gradually increased from controls across patients with preeclampsia to those with gestational hypertension. Similar changes were observed for 24-h systolic BP-variability indices. LV longitudinal and circumferential strains gradually decreased from controls across women with gestational hypertension to patients with preeclampsia. Radial strain was significantly lower in women with preeclampsia than in controls. Indices of short- and long-term BP variability were independent of BP and demographic and echocardiographic parameters associated with LV longitudinal and circumferential strain. In conclusion, LV mechanics are impaired in women with gestational hypertension and preeclampsia compared with LV mechanics in normotensive controls. Short- and long-term BP variability was higher in patients with hypertensive disorders and was significantly associated with longitudinal and circumferential strains., (© 2021. The Author(s), under exclusive licence to The Japanese Society of Hypertension.)
- Published
- 2021
- Full Text
- View/download PDF
35. Bridging the Gap Between Physical Health and Autism Spectrum Disorder.
- Author
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Sala R, Amet L, Blagojevic-Stokic N, Shattock P, and Whiteley P
- Abstract
Autism spectrum disorder (ASD) is a highly complex and heterogeneous developmental disorder that affects how individuals communicate with other people and relate to the world around them. Research and clinical focus on the behavioural and cognitive manifestations of ASD, whilst important, have obscured the recognition that ASD is also commonly associated with a range of physical and mental health conditions. Many physical conditions appear with greater frequency in individuals with ASD compared to non-ASD populations. These can contribute to a worsening of social communication and behaviour, lower quality of life, higher morbidity and premature mortality. We highlight some of the key physical comorbidities affecting the immune and the gastrointestinal systems, metabolism and brain function in ASD. We discuss how healthcare professionals working with individuals with ASD and parents/carers have a duty to recognise their needs in order to improve their overall health and wellbeing, deliver equality in their healthcare experiences and reduce the likelihood of morbidity and early mortality associated with the condition., Competing Interests: Dr Sala has been an advisor to or has received honoraria from Takeda. Dr Paul Whiteley reports grants from The Robert Luff Foundation, during the preparation of this paper. The authors report no other conflicts of interest in this work., (© 2020 Sala et al.)
- Published
- 2020
- Full Text
- View/download PDF
36. Evaluation of commercial forensic DNA extraction kits for decontamination and extraction of DNA from biological samples contaminated with radionuclides.
- Author
-
Toole K, Roffey P, Young E, Cho K, Shaw T, Smith M, and Blagojevic N
- Subjects
- Bombs, Equipment Contamination, Forensic Genetics, Humans, Male, Spectrometry, Gamma, DNA isolation & purification, DNA radiation effects, DNA Fingerprinting, Decontamination, Radioisotopes, Specimen Handling instrumentation
- Abstract
In preparing to respond to security incidents involving radioactive material, States should consider how they might address the unique challenge of analysing forensic evidence contaminated with these materials. In the case of DNA evidence, previous research has suggested that commercial forensic DNA extraction kits may be able to remove radioactive contamination from biological samples. If viable, this would allow the extraction and decontamination of biological samples to be undertaken in a laboratory equipped to handle radioactive material, with the subsequent quantification and profiling of extracted DNA performed in a conventional forensics laboratory. In order to inform the development of an operational capability, this study sought to expand upon previous work to provide a more comprehensive quantitative assessment of the efficacy of commercial DNA extraction kits for the removal of radionuclide contamination from biological samples and the quality of the resultant DNA profiles. Three commercial DNA extraction kits were tested for their ability to remove contaminating radionuclides. Two of these kits proved more effective at removing radionuclide contamination and produced DNA extracts of higher quality. Under all conditions tested in this study, decontamination efficiency was sufficient to allow the release of samples to a forensic laboratory. However, consistent with a prudent approach to radiation safety it is recommended that all samples be screened by gamma spectrometry prior to their release to a forensic laboratory in order to verify decontamination., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
37. Wild Bilberry ( Vaccinium myrtillus L., Ericaceae) from Montenegro as a Source of Antioxidants for Use in the Production of Nutraceuticals.
- Author
-
Brasanac-Vukanovic S, Mutic J, Stankovic DM, Arsic I, Blagojevic N, Vukasinovic-Pesic V, and Tadic VM
- Subjects
- Chromatography, High Pressure Liquid, Minerals chemistry, Montenegro, Phenols analysis, Phenols chemistry, Phytochemicals chemistry, Phytochemicals pharmacology, Plant Extracts, Anthocyanins chemistry, Anthocyanins pharmacology, Antioxidants chemistry, Antioxidants pharmacology, Dietary Supplements, Vaccinium myrtillus chemistry
- Abstract
The aim of this study was to establish correlation of chemical composition and antioxidant activity of bilberry plants from Montenegro. Total phenolic, tannin, flavonoid, procyanidin and anthocyanin contents were determined in fruits and leaves extracts using spectrophotometric methods, while the measurements of metal content was carried out in an Inductively Coupled Atomic Emission Spectrometer. Qualitative and quantitative analyses of major phenolics were achieved by HPLC. In the investigated extracts, the most abundant phenolic was chlorogenic acid, followed by protocatechuic acid, while resveratrol, isoquercetin, quecetin and hyperoside were also present in significant quantities. Antioxidant potential was evaluated using two in vitro assays-FRAP and DPPH-being in the accordance with the cyclic voltammetry tests, performed as well. The results revealed that all the investigated extracts were rich in phenolic and essential mineral constituents, with significant antioxidant activity, depending on the polyphenolic and mineral contents, which was confirmed by principal component analysis.
- Published
- 2018
- Full Text
- View/download PDF
38. Comparing results of X-ray diffraction, µ-Raman spectroscopy and neutron diffraction when identifying chemical phases in seized nuclear material, during a comparative nuclear forensics exercise.
- Author
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Rondahl SH, Pointurier F, Ahlinder L, Ramebäck H, Marie O, Ravat B, Delaunay F, Young E, Blagojevic N, Hester JR, Thorogood G, Nelwamondo AN, Ntsoane TP, Roberts SK, and Holliday KS
- Abstract
This work presents the results for identification of chemical phases obtained by several laboratories as a part of an international nuclear forensic round-robin exercise. In this work powder X-ray diffraction (p-XRD) is regarded as the reference technique. Neutron diffraction produced a superior high-angle diffraction pattern relative to p-XRD. Requiring only small amounts of sample, µ-Raman spectroscopy was used for the first time in this context as a potentially complementary technique to p-XRD. The chemical phases were identified as pure UO
2 in two materials, and as a mixture of UO2 , U3 O8 and an intermediate species U3 O7 in the third material.- Published
- 2018
- Full Text
- View/download PDF
39. Laser acupuncture for myofascial pain of the masticatory muscles. A controlled pilot study.
- Author
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Katsoulis J, Ausfeld-Hafter B, Windecker-Gétaz I, Katsoulis K, Blagojevic N, and Mericske-Stern R
- Subjects
- Acupuncture Analgesia instrumentation, Adult, Double-Blind Method, Female, Humans, Male, Masticatory Muscles physiopathology, Middle Aged, Pain Measurement, Pilot Projects, Prospective Studies, Treatment Outcome, Young Adult, Acupuncture Analgesia methods, Facial Pain therapy, Low-Level Light Therapy, Temporomandibular Joint Dysfunction Syndrome therapy
- Abstract
Purpose: The purpose of this investigation was to evaluate the effectiveness of laser acupuncture within the scope of a pilot study., Methods: 108 adult patients were examined and of those eleven patients were included in the prospective pilot study. These patients took part voluntarily and were diagnosed with tendomyopathy of the masticatory musculature with maximum face and jaw pain on a visual analogous scale VAS > or = 30 in the last 14 days. Four patients wanted to be sure not to be assigned to the placebo group and were treated with the laser (group1, verum open, N = 4). The remaining seven were split by means of block randomisation into groups 2 (verum blind, N = 3) and 3 (placebo blind, N = 4). Two local points (ST 6, SI 18) and two distant points (SI 3, LI 4) on both sides of the body were stimulated (groups 1 and 2) or placebo-stimulated (group 3) with the LASERneedle machine for 15 minutes twice a week for three weeks (6 sessions). After three months a clinical follow-up was carried out, which included a standardised questionnaire as to the maximum pain intensity (VAS and verbal scale) and on the need for further treatment. A pain reduction (VAS) of about 50% was evaluated as a success., Results: Pain decreased on average 40 VAS points for ten of eleven patients. The pain reduction on the VAS in group 1 (verum open) was more than 50% for all four patients, in group 3 (placebo blind) for three of four patients, and in group 2 (verum blind) all remained under 50%. The evaluation on the verbal scale showed a pain reduction from moderate to very strong pains initially, to moderate, light and no pain after three months for all three groups., Discussion: The range of application of the laser was limited by the narrow inclusion criteria of the pilot study. The laser acupuncture (open and blinded) did not show a negative effect in any group. The pain reduction was strongest with the blinded patients of the placebo group. The worst performance was in the blinded group with laser acupuncture., Conclusion: Due to the low number of participants, no clear conclusion can be drawn. Laser needle acupuncture may be a treatment option for patients with an interest in a noninvasive, complementary therapy. But clarification and treatment planning on an individual basis must take place first.
- Published
- 2010
40. Thorium in mineral products.
- Author
-
Collier DE, Brown SA, Blagojevic N, Soldenhoff KH, and Ring RJ
- Subjects
- Neutron Activation Analysis, Spectrometry, X-Ray Emission, Minerals chemistry, Thorium analysis
- Abstract
Many ores contain low levels of thorium. When these ores are processed, the associated radioactivity can be found in mineral concentrates, intermediates and final products. There is an incentive for industries to remove radioactivity from mineral products to allow the movement and sale of these materials, both nationally and internationally, without the need for licensing. Control of thorium in various products involves the development and optimisation of process steps to be able to meet product specifications. The Australian Nuclear Science and Technology Organisation (ANSTO) has undertaken a range of R & D programmes targeting the treatment of thorium-bearing minerals. This paper discusses the application of a microprobe technique for siting radioactivity in zircon and ilmenite and the problems experienced in measuring the concentrations in solid rare earth products.
- Published
- 2001
- Full Text
- View/download PDF
41. Alpha- and beta-emitting radiolanthanides in targeted cancer therapy: the potential role of terbium-149.
- Author
-
Allen BJ and Blagojevic N
- Subjects
- Alpha Particles, Beta Particles, Humans, Lymphatic Metastasis, Neoplasm Metastasis, Neoplasm Staging, Neoplasms blood supply, Neoplasms pathology, Neovascularization, Pathologic, Metals, Rare Earth therapeutic use, Neoplasms radiotherapy, Radioisotopes therapeutic use, Terbium therapeutic use
- Abstract
The efficacy of systemic cancer therapy rests on the ability of a toxin to be preferentially located in cancer cells, so that cancer cell kill is maximized and normal tissue spared. This requires that the lifetime of the toxin be less than the lifetime of the carrier in the body, effectively ruling out chemical toxins, as they remain effective until excreted from the body. The requirement of localization of dose to the cancer cell makes radioactive beta-emitting radionuclides unattractive. Alpha-emitting radionuclides are much more appropriate toxins, as their efficacy depends on the high energy and short range of the alpha particles, and terbium-149 is shown to be the most efficacious of these. However, the merit of various alpha- and beta-emitting radionuclides depends on the stage and type of cancer. Recommendations are made with respect to the matching of the target cancer with required properties of the radiolabel and carrier.
- Published
- 1996
- Full Text
- View/download PDF
42. Hydrogen background in total body nitrogen estimations.
- Author
-
Humphries IR, Allen BJ, Blagojevic N, and Gaskin KJ
- Subjects
- Adult, Deuterium Oxide, Humans, Hydrogen, Neutron Activation Analysis, Neutrons, Reproducibility of Results, Scattering, Radiation, Models, Theoretical, Nitrogen analysis, Nutrition Assessment
- Abstract
Total body nitrogen (TBN) is measured by in vivo prompt gamma neutron capture analysis. Usually the background under the nitrogen peak is subtracted before calculating TBN from the ratio of nitrogen counts (at 10.8 MeV) to hydrogen counts (at 2.2 MeV). The hydrogen acts as an internal standard. The background under the hydrogen peak is usually ignored. The current study was undertaken to measure the variation of the hydrogen background (HB) in patients of different sizes and to determine whether the accuracy of TBN measurements is improved when an HB correction is incorporated. Heavy-water (D2O) phantoms were used to quantify patient HB. D2O simulates patient neutron scattering without contributing to the hydrogen peak. Equations were developed to predict HB in patient measurements. HB was found to vary from 9% of total counts for a 99 kg subject to 19% for a 7 kg infant. It was demonstrated that the accuracy of TBN measurements is improved for child-sized anthropometric phantoms of known composition when an HB correction is incorporated.
- Published
- 1995
- Full Text
- View/download PDF
43. Performance of the bismuth germanate total body chlorine analyzer.
- Author
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Blagojevic N, Allen BJ, and Russell J
- Subjects
- Anorexia Nervosa metabolism, Evaluation Studies as Topic, Extracellular Space chemistry, Humans, Hydrogen analysis, Models, Structural, Neutron Activation Analysis statistics & numerical data, Whole-Body Counting methods, Whole-Body Counting statistics & numerical data, Bismuth, Body Composition, Chlorine analysis, Germanium, Neutron Activation Analysis methods
- Published
- 1993
- Full Text
- View/download PDF
44. Total body protein status of males infected with the human immunodeficiency virus.
- Author
-
Oliver CJ, Rose A, Blagojevic N, Dwyer R, Gold J, and Allen BJ
- Subjects
- Adult, Body Water chemistry, Electric Impedance, Humans, Male, Middle Aged, Neutron Activation Analysis, Nitrogen analysis, Nutrition Disorders metabolism, Time Factors, Weight Loss physiology, Body Composition physiology, HIV Infections metabolism, Proteins analysis
- Published
- 1993
- Full Text
- View/download PDF
45. A total body nitrogen facility for paediatric use.
- Author
-
Baur LA, Allen BJ, Rose A, Blagojevic N, and Gaskin KJ
- Subjects
- Australia, Child, Humans, Neutrons, Facility Design and Construction, Nitrogen analysis, Protein-Energy Malnutrition prevention & control
- Abstract
The design, calibration and evaluation of a facility for in vivo prompt gamma neutron capture analysis of total body nitrogen in children is described. The patient is scanned in both supine and prone positions, across a vertically collimated beam from a 1 GBq 252Cf fission source. Two NaI(T1) detectors are placed on either side of the patient, perpendicular to both the neutron beam and the scanning direction. The effective dose equivalent delivered to a child during an 840 s scan is approximately 0.14 mSv (QF = 10). Correction factors for nitrogen background (width-dependent), hydrogen background (1-4% of hydrogen gamma ray peak) and the differential attenuation of nitrogen and hydrogen gamma rays (width-dependent) can be applied to the measured nitrogen-to-hydrogen gamma ray counts ratio. By using the mass of hydrogen (based on body mass and fat mass) as an internal standard, the nitrogen mass can then be determined. Measurements with a urea-containing box phantom show that the current precision (CV) of the net nitrogen counts and of the nitrogen-to-hydrogen counts ratio is +/- 2.0% and +/- 1.5%, respectively. Using small anthropomorphic and other phantoms, estimation of the mass of nitrogen has a precision of +/- 1.4 to 5.4% and an accuracy of 97.1 to 101.5%.
- Published
- 1991
- Full Text
- View/download PDF
46. Nitrogen deposition in malnourished children with cystic fibrosis.
- Author
-
Baur LA, Waters DL, Allen BJ, Blagojevic N, and Gaskin KJ
- Subjects
- Adolescent, Anthropometry, Body Composition, Body Height, Body Weight, Child, Child, Preschool, Cystic Fibrosis pathology, Female, Humans, Longitudinal Studies, Male, Nutrition Disorders metabolism, Nutritional Status, Puberty, Reference Values, Cystic Fibrosis complications, Nitrogen pharmacokinetics, Nutrition Disorders etiology
- Abstract
To determine the protein nutritional status of 21 malnourished children with cystic fibrosis (CF), total body nitrogen (TBN) was measured and the results were compared with 21 control subjects. CF patients demonstrated a lower TBN (P less than 0.001). When matched for height (n = 10) or bone age (n = 13), the CF patients still had a depressed TBN/height or TBN/lean body mass (P less than 0.05). To assess nitrogen deposition during nutritional rehabilitation, repeat TBN measurements were performed on the 21 CF patients. Nitrogen deposition ranged from -230 to 550 g/y and correlated with weight velocity (r = 0.78, P less than 0.001). Increased nitrogen deposition (greater than 150 g/y) was generally associated with normal height gain (height velocity SD score greater than -2.00) and weight gain (greater than 2.0 kg/y). Decreased nitrogen deposition was associated with poor weight gain but did not preclude normal linear growth. These data suggest an important role for TBN estimations in defining protein nutritional status in children and indicate that skeletal growth can continue in the presence of minimal nitrogen deposition.
- Published
- 1991
- Full Text
- View/download PDF
47. Determination of total body water by Fourier transform infrared analysis.
- Author
-
Blagojevic N, Allen BJ, Gaskin KJ, and Baur LA
- Subjects
- Adult, Deuterium, Female, Humans, Infrared Rays, Male, Middle Aged, Nitrogen analysis, Potassium analysis, Reference Values, Reproducibility of Results, Body Water, Fourier Analysis
- Abstract
A new technique for determining body water using deuterium isotope dilution and Fourier transform infrared (FTIR) analysis is described. The advantages of the FTIR over conventional dispersion and filter infrared instruments include greater flexibility through computer controlled operations and availability of 'on-line' analytical software. The technique was further improved by the development of a simple procedure for determining D2O concentration in untreated serum samples. A validation study of six normal adults showed that the fat-free-mass determined from the deuterium-space (total body water) correlated well with the results obtained by total body nitrogen (r = 0.997), total body potassium (r = 0.996) and anthropometric (r = 0.995) measurements.
- Published
- 1990
48. Total-body nitrogen by neutron activation in maintenance dialysis.
- Author
-
Pollock CA, Allen BJ, Warden RA, Caterson RJ, Blagojevic N, Cocksedge B, Mahony JF, Waugh DA, and Ibels LS
- Subjects
- Absorption, Adult, Aged, Anthropometry, Creatinine pharmacokinetics, Dietary Carbohydrates administration & dosage, Dietary Fats administration & dosage, Dietary Proteins administration & dosage, Dietary Proteins pharmacokinetics, Energy Intake, Female, Follow-Up Studies, Glucose pharmacokinetics, Humans, Longitudinal Studies, Male, Metabolic Clearance Rate, Middle Aged, Neutron Activation Analysis, Nitrogen analysis, Nitrogen pharmacokinetics, Nutrition Assessment, Peritoneal Dialysis, Continuous Ambulatory
- Abstract
The nutritional status of 35 patients on continuous ambulatory peritoneal dialysis (CAPD) was assessed by the traditional methods of dietary history and anthropometric measurements, and was compared with simultaneous measurements of dietary protein intake (DPI) calculated from urea generation rate and total-body nitrogen (TBN) assessment by prompt neutron activation analysis (PNAA). DPI as determined by dietary recall was significantly higher than calculated DPI (1.04 +/- 0.42 v 0.84 +/- 0.28 g/kg/d; P less than 0.001). Anthropometric measurements did not differ significantly from the predicted normal values for sex, height, and age. However, PNAA measurements of TBN demonstrated significant nitrogen depletion, being 88.2% of normal for males (P less than 0.001) and 87.5% of normal for females (P less than 0.002); TBN correlated significantly with DPI calculated from urea generation rate (P less than 0.05). Assessment of these 35 patients 17.5 +/- 4.4 months later, demonstrated that patients who died or suffered serious morbidity requiring transfer from CAPD (n = 10) had significantly lower TBN than those who remained on CAPD or underwent successful renal transplantation (n = 25): 80.0% v 93.2% of normal (P less than 0.01). No difference in anthropometric measurements was observed between the two groups of patients. Eleven patients on maintenance home or satellite hemodialysis underwent identical dietary, anthropometric, and TBN assessments and results were similar to those obtained in the CAPD population, although no correlation with calculated DPI and TBN was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1990
- Full Text
- View/download PDF
49. Changes in body protein composition following aortic reconstruction.
- Author
-
Fletcher JP, Allen BJ, and Blagojevic N
- Subjects
- Aged, Body Constitution, Body Weight, Female, Humans, Male, Middle Aged, Neutron Activation Analysis, Postoperative Complications, Time Factors, Aorta surgery, Aortic Diseases surgery, Body Composition, Nitrogen analysis, Proteins analysis
- Abstract
Major surgery initiates a stress response due to the body's neuroendocrine reaction which leads to a breakdown of muscle protein with an increased urinary nitrogen excretion and a negative nitrogen balance. In vivo neutron activation analysis (IVNAA) is a technique which measures total body nitrogen. A total of 23 IVNAA studies were performed in six patients having aortic reconstruction to assess the effect of this major operation on body nitrogen and to determine the time required for a return to the pre-operative state. Aortic surgery caused a mean decrease of 2.9% in bodyweight (from a mean of 65.4 kg to 63.5 kg) but a much greater decrease of 9.9% in total body nitrogen (from a mean of 1778 g to 1602 g). Only two of six patients had recovered to pre-operative values by the end of the study period which extended for a mean of 92 days.
- Published
- 1990
50. Body protein of patients undergoing haemodialysis.
- Author
-
Allman MA, Allen BJ, Stewart PM, Blagojevic N, Tiller DJ, Gaskin KJ, and Truswell AS
- Subjects
- Adult, Anthropometry, Body Mass Index, Female, Humans, Male, Middle Aged, Neutron Activation Analysis, Protein-Energy Malnutrition etiology, Regression Analysis, Nitrogen analysis, Protein-Energy Malnutrition diagnosis, Proteins analysis, Renal Dialysis adverse effects
- Abstract
The total body protein status of 18 patients undergoing regular haemodialysis was assessed by measuring total body nitrogen (TBN) using in vivo neutron activation analysis (NAA). Eighteen healthy controls, who were selected according to their height, age and sex match with the patients were also measured. The male and female patients were both found to have lower mean values for total body protein (P less than 0.01, P less than 0.025 respectively) although they had similar weights compared with their matched controls. Seven patients were measured on further occasions and only two patients showed a change in their body protein. One female showed an increase of 11 per cent in body protein (with an increase of 25 per cent in body weight) after intensive nutritional repletion therapy. In vivo NAA provides a direct means of measuring body protein and is a reliable method to monitor changes with treatment regimes.
- Published
- 1990
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