Search results for "ISOTOPES"

Poisoning histories in the Italian renaissance: The case of Pico Della Mirandola and Angelo Poliziano.

2018

Giovanni Pico della Mirandola and Angelo Poliziano were two of the most important humanists of the Italian Renaissance. They died suddenly in 1494 and their deaths have been for centuries a subject of debate. The exhumation of their remains offered the opportunity to study the cause of their death through a multidisciplinary research project. Anthropological analyses, together with documentary evidences, radiocarbon dating and ancient DNA analysis supported the identification of the remains attributed to Pico. Macroscopic examination did not reveal paleopathological lesions or signs related to syphilis. Heavy metals analysis, carried out on bones and mummified tissues, showed that in Pico's…

Iodine determination in food samples using inductively coupled plasma isotope dilution mass spectrometry.

1998

Two different sample treatment methods are used in connection with inductively coupled plasma isotope dilution mass spectrometry for accurate and precise determinations of iodine traces in food samples. 129I-enriched iodate is applied as a spike compound for the isotope dilution step. Extraction of iodine by tetramethylammonium hydroxide (TMAH) solution at high temperatures in a closed vessel is one of the sample treatment methods. The other one is a complete decomposition of the sample with a mixture of perchloric acid and nitric acid using microwave assistance. By analyzing different certified reference materials (three milk powders with different iodine levels, BCR CRM 63, 150, and 151; …

Management of painful bone metastases.

2007

PURPOSE OF REVIEW: This review examines recent data on the pathophysiology and mechanisms of bone pain; it highlights the use of multiple and interdisciplinary treatments rather than sole use of traditional analgesics. RECENT FINDINGS: Bone pain has been shown to have a unique pathophysiology. Recent experimental (animal) models have revealed that, parallel to increased bone destruction, ipsilateral spinal cord segments that receive primary input from the cancerous femur exhibit several notable neurochemical changes. These mandate the use of opioid doses sufficient to inhibit the observed nociceptive behaviours; these doses are greater than those required to alleviate pain behaviours of com…

Radionuclides in wastewater treatment plants: monitoring of Sicilian plants.

2015

Three Sicilian wastewater treatment plants were monitored to assess the occurrence and the behaviour of radionuclides. Two sampling campaigns (screening and long-term) were carried out during which liquid and solid samples have been analysed. It was found that 131I mostly occurred in the samples analysed during the screening campaign (43% of the analysed samples contained 131I). High 131I specific activity was found in the mixed liquor, recycled sludge and dehydrated sludge samples. This finding was mainly due to the tendency of 131I to be associated with solid particles. During the long-term sampling campaign an influence of the sludge retention time (SRT) on the 131I behaviour was found. …

Billion-Fold Enhancement in Sensitivity of Nuclear Magnetic Resonance Spectroscopy for Magnesium Ions in Solution

2014

Beta-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. Beta-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, beta-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. 31Mg b-NMR spectra are measured for as few as 10^7 magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that beta-NMR is applicable for the…

A new method for radiochemical separation of arsenic from irradiated germanium oxide.

2005

Abstract Radioarsenic labelled radiopharmaceuticals could be a valuable asset to Positron Emission Tomography (PET). In particular, the long half-lives of 72 As ( T 1/2 =26 h) and 74 As ( T 1/2 =17.8 d) allow to investigate slow physiological or metabolical processes, like the enrichment and distribution of antibodies in tumor tissue. This work describes the direct production of no-carrier-added (nca) arsenic isotopes *As, with *=71, 72, 73, 74 or 77, the reaction to [*As]AsI 3 and its radiochemical separation from the irradiated solid germanium oxide via polystyrene-based solid-phase extraction. The germanium oxide target, irradiated at a cyclotron or a nuclear reactor, is dissolved in con…

The Influence of Diffusion of Inert Gases on the Determination of Blood Flow by the Clearance Method

1968

Progress on nuclear reaction rates affecting the stellar production of 26Al

2023

Abstract The radioisotope 26Al is a key observable for nucleosynthesis in the Galaxy and the environment of the early Solar System. To properly interpret the large variety of astronomical and meteoritic data, it is crucial to understand both the nuclear reactions involved in the production of 26Al in the relevant stellar sites and the physics of such sites. These range from the winds of low- and intermediate-mass asymptotic giant branch stars; to massive and very massive stars, both their Wolf–Rayet winds and their final core-collapse supernovae (CCSN); and the ejecta from novae, the explosions that occur on the surface of a white dwarf accreting material from a stellar companion. Several r…

Illustration of constrained composition statistical methods in the interpretation of radionuclide concentrations in the moss Pleurozium schreberi.

2013

In this work we have used moss Pleurozium schreberi as a bioindicator of radioactive materials in environment. The following radionuclides were determined in moss samples: (137)Cs, (40)K, (210)Pb, (212)Pb, (214)Pb, (214)Bi, (231)Th, (235)U and (228)Ac, but not all of them in each sample. The highest activity concentrations were found for naturally occurring (210)Pb, (40)K and the artificial isotope (137)Cs. Activities of radioisotopes were recalculated into mass concentrations and the statistical methods intended for constrained data processing were used. Analysis of our results showed at most a weak relationship between radioisotope mass concentrations in moss. It was supposed that concent…

Fitted dosimetric parameters of high dose-rate 192Ir sources according to the AAPM TG43 formalism

2001

The purpose of this study is to find fitted functional forms to the anisotropy function, F(r,θ), and the radial dose function, g(r), in order to characterize dose-rate distributions around all the high-intensity 192 Ir sources currently in use. Dosimetry data are at present available as tables for: the microSelectron HDR (“classic” and “new” design models), the PDR source, and the VariSource HDR source, expressed in terms of the AAPM Task Group No. 43 recommendations. There is only one paper out which introduces a functional form to fit the anisotropy function, but only for symmetric sources with respect to the transverse axis. However, dosimetric data of the HDR and PDR sources mentioned a…