26 research outputs found
Rapid method for radiostrontium determination in milk in emergency situations using PS resin
[EN] This study describes a new and rapid procedure for radiostrontium determination in milk samples based on the use of plastic scintillation resins (PS resins). The proposed method reduces the time of analysis by at least 2 h by combining separation and measurement preparation into a single step and optimizing the pre-treatment steps. The method is robust and reproducible, with good total recoveries (65% on average) and a relative bias for total radiostrontium activity (Sr-89 + Sr-90) below 7%. The minimum detectable activity for 100 mL of milk sample measured for 60 min is about 0.34 Bq L-1. The proposed method can quantify radiostrontium content in 5 h, which makes it suitable for use in emergency situations.The authors are grateful to the Spanish Ministerio de Economia y Competitividad (MINECO) for financial support, under CTM2014-02020 and the Catalan Agencia de Gestio d'Ajuts Universitaris i de Recerca (AGAUR) for financial support, under 2014-SGR-1277. We should also like to thank the Universitat Politecnica de Valencia for finantial support under the "Programa propio para la Formacion de Personal Investigador (FPI) de la UniversitatPolitecnica de Valencia - Subprograma 100.Sáez-Muñoz, M.; Bagán, H.; TarancĂłn, A.; GarcĂa, JF.; Ortiz MoragĂłn, J.; Martorell Alsina, SS. (2018). Rapid method for radiostrontium determination in milk in emergency situations using PS resin. Journal of Radioanalytical and Nuclear Chemistry. 315(3):543-555. https://doi.org/10.1007/s10967-017-5682-3S5435553153International Atomic Energy Agency (2015) The fukushima daiichi accident, technical radiological consequences, vol 4. IAEA, ViennaInternational Atomic Energy Agency (2006) Environmental consequences of the chernobyl accident and their remediation: 20 years of experience, Report of the UN Chernobyl forum expert group “environment”, radiological assessment reports Series No. 8, IAEA, ViennaPovinec PP, Hirose K, Aoyama M (2013) Fukushima accident: radioactivity impact on the environment. Elsevier, ChinaCouncil Regulation (Euratom) 2016/52 of 15 January 2016 laying down maximum permitted levels of radioactive contamination of food and feed following a nuclear accident or any other case of radiological emergency, and repealing regulation (Euratom) No 3954/87 and commission regulations (Euratom) No 944/89 and (Euratom) No 770/90Vajda N, Kim CK (2010) Determination of radiostrontium isotopes: a review of analytical methodology. Appl Radiat Isot 68:2306–2326Brun S, Bessac S, Uridat D, Boursier B (2002) Rapid method for the determination of radiostrontium in milk. J Radioanal Nucl Chem 253(2):191–197Maxwell SL, Culligan BK (2009) Rapid method for determination of radiostrontium in emergency milk samples. J Radioanal Nucl Chem 279(3):757–760Kabai E, Hornung L, Savkin BT, Poppitz-Spuhler A, Hiersche L (2011) Fast method and ultra fast screening for determination of 90Sr in milk and dairy products. Sci Total Environ 410–411:235–240International Atomic Energy Agency (2013) Rapid simultaneous determination of 89Sr and 90Sr in milk: a procedure using cerenkov and scintillation counting, analytical quality in nuclear applications no. IAEA/AQ/27, IAEA, ViennaBagán H, TarancĂłn A, Rauret G, GarcĂa JF (2011) Radiostrontium separation and measurement in a single step using plastic scintillators plus selective extractants application to aqueous sample analysis. Anal Chim Acta 686:50–56Barrera J, TarancĂłn A, Bagán H, GarcĂa JF (2016) A new plastic scintillation resin for single-step separation, concentration and measurement of technetium-99. Anal Chim Acta 936:259–266Lluch E, Barrera J, TarancĂłn A, Bagán H, GarcĂa JF (2016) Analysis of 210Pb in water samples with plastic scintillation resins. Anal Chim Acta 940:38–45Santiago L, TarancĂłn A, GarcĂa JF (2016) Influence of preparation parameters on the synthesis of plastic scintillation microspheres and evaluation of sample preparation. Adv Powder Technol 27(4):1309–1317Savitzky A, Golay MJE (1964) Smoothing and differentiation of data by simplified least-squares procedures. Anal Chem 36:1627–1639Currie LA (1968) Limits for qualitative detection and quantitative determination. Application to radiochemistry. Anal Chem 40(3):586–593UNE 34829:1983, Determination of the calcium content of milkISO 12081:2010, IDF 36:2010, Milk—Determination of calcium content—titrimetric methodHeckel A, Vogl K (2009) Rapid method for determination of the activity concentrations of 89Sr and 90Sr. Appl Radiat Isot 67:794–796Kabai E, Savkin B, Mehlsam I, Poppitz-Spuhler A (2017) Combined method for the fast determination of pure beta emitting radioisotopes in food samples. J Radioanal Nucl Chem 311:1401–1408Eikenberg J, Beer H, RĂĽthi M, Zumsteg I, Vetter A (2005) Precise determination of 89Sr and 90Sr/90Y in various matrices: the LSC 3-window approach. LSC2005 Advances in Liquid Scintillation Spectrometry, Radiocarbon, AZ, pp 237–249Kim CK, Al-Hamwi A, Toervenyi A, Kis-Benedek G, Sansone U (2009) Validation of rapid method for the determination of radiostrontium in milk. Appl Radiat Isot 67:786–79
A retrospective case-control study of hepatitis C virus infection and oral lichen planus in Japan: association study with mutations in the core and NS5A region of hepatitis C virus
<p>Abstract</p> <p>Background</p> <p>The aims of this study were to assess the prevalence of hepatitis C virus (HCV) infection in Japanese patients with oral lichen planus and identify the impact of amino acid (aa) substitutions in the HCV core region and IFN-sensitivity-determining region (ISDR) of nonstructural protein 5A (NS5A) associated with lichen planus.</p> <p>Methods</p> <p>In this retrospective study, 59 patients (group 1-A) with oral lichen planus among 226 consecutive patients who visited our hospital and 85 individuals (group 1-B, controls) with normal oral mucosa were investigated for the presence of liver disease and HCV infection. Risk factors for the presence of oral lichen planus were assessed by logistic regression analysis. We compared aa substitutions in the HCV core region (70 and/or 91) and ISDR of NS5A of 12 patients with oral lichen planus (group 2-A) and 7 patients who did not have oral lichen planus (group 2-B) among patients (high viral loads, genotype 1b) who received interferon (IFN) therapy in group1-A.</p> <p>Results</p> <p>The prevalence of anti-HCV and HCV RNA was 67.80% (40/59) and 59.32% (35/59), respectively, in group 1-A and 31.76% (27/85) and 16.47% (14/85), respectively, in group 1-B. The prevalence of anti-HCV (<it>P </it>< 0.0001) and HCV RNA (<it>P </it>< 0.0001) in group 1-A was significantly higher than those in group 1-B. According to multivariate analysis, three factors - positivity for HCV RNA, low albumin level (< 4.0 g/dL), and history of smoking - were associated with the development of oral lichen planus. The adjusted odds ratios for these three factors were 6.58, 3.53 and 2.58, respectively, and each was statistically significant. No significant differences in viral factors, such as aa substitutions in the core region and ISDR of NS5A, were detected between the two groups (groups 2-A and -B).</p> <p>Conclusion</p> <p>We observed a high prevalence of HCV infection in patients with oral lichen planus. Longstanding HCV infection, hypoalbuminemia, and smoking were significant risk factors for the presence of oral lichen planus in patients. It is advisable for Japanese patients with lichen planus to be tested for HCV infection during medical examination.</p
Behavioral and Cognitive Improvement Induced by Novel Imidazoline I2 Receptor Ligands in Female SAMP8 Mice
As populations increase their life expectancy, age-related neurodegenerative disorders such as Alzheimer's disease have become more common. I2-Imidazoline receptors (I2-IR) are widely distributed in the central nervous system, and dysregulation of I2-IR in patients with neurodegenerative diseases has been reported, suggesting their implication in cognitive impairment. This evidence indicates that high-affinity selective I2-IR ligands potentially contribute to the delay of neurodegeneration. In vivo studies in the female senescence accelerated mouse-prone 8 mice have shown that treatment with I2-IR ligands, MCR5 and MCR9, produce beneficial effects in behavior and cognition. Changes in molecular pathways implicated in oxidative stress, inflammation, synaptic plasticity, and apoptotic cell death were also studied. Furthermore, treatments with these I2-IR ligands diminished the amyloid precursor protein processing pathway and increased Aβ degrading enzymes in the hippocampus of SAMP8 mice. These results collectively demonstrate the neuroprotective role of these new I2-IR ligands in a mouse model of brain aging through specific pathways and suggest their potential as therapeutic agents in brain disorders and age-related neurodegenerative diseases. Keywords Imidazoline I2 receptors (2-imidazolin-4-yl)phosphonates Behavior Cognition Neurodegeneration Neuroprotection Agin
PLASTIC SCINTILLATORS: A POWERFUL TOOL TO REDUCE MIXED WASTE
ABSTRACT Wastes containing radioactive and organic compounds (mixed wastes) are difficult to dispose because of the regulations established for nuclear and hazardous wastes. Mixed wastes originate mainly in the emulsions generated in beta emitter determinations by Liquid Scintillation techniques. The use of plastic scintillators instead of liquid cocktails may facilitate the segregation, after measurement, of sample and scintillator without introducing additional wastes in the measurement step. In this study, we compare the capability of Plastic Scintillation (PS) versus Liquid Scintillation (LS) and Cerenkov (C) techniques to determine beta emitters in routine measurements. Results obtained show that high and medium energy beta emitters (Sr-90/Y-90 and C-14) can be quantified in aqueous samples by using PS with similar relative errors (< 5%) as those obtained by LS or C, for any activity level considered. For low energy emitters (H-3), best results using PS are achieved for medium activity levels. Additionally, measurements performed in solutions including alpha (Pu-238) and beta-gamma (Cs-134) emitters confirm the capability of PS to extent the application of this technique to the determination of these types of isotopes
Plastic Scintillation nanoparticles produced by supercritical anti-solvent precipitation
International audienceno abstrac
Single-blind randomized clinical trial to evaluate clinical and radiological outcomes after one year of immediate versus delayed implant placement supporting full-arch prostheses
Purpose: To evaluate and compare peri-implant health, marginal bone loss and success of immediate and delayed
implant placement for rehabilitation with full-arch fixed prostheses.
Material and Methods: The present study was a prospective, randomized, single-blind, clinical preliminary trial.
Patients were randomized into two treatment groups. In Group A implants were placed immediately post-extraction and in Group B six months after extraction. The following control time-points were established: one week,
six months and twelve months after loading. Measurements were taken of peri-implant crevicular fluid volume,
plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of
mucositis. Implant success rates were evaluated for the two groups. The study sample included fifteen patients
(nine women and six men) with a mean average age of 63.7 years. One hundred and forty-four implants were
placed: 76 placed in healed sites and 68 placed immediately.
Results: At the moment of prosthetic loading, keratinized mucosa width and probing depth were higher in immediate implants than delayed implants, with statistically significant differences. However, after six and twelve
months, differences between groups had disappeared. Bone loss was 0.54 ± 0.39 mm for immediate implants and
0.66 ± 0.25 mm for delayed implants (p=0.201). No implants failed in either group.
Conclusions: The present study with a short follow-up and a small sample yielded no statistically significant differences in implant success and peri-implant marginal bone loss between immediate and delayed implants with
fixed full-arch prostheses. Peri-implant health showed no statistically significant differences for any of the studied
parameters (crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified
gingival index and presence of mucositis) at the twelve-month follow-up
Investigation of a new approach for 36Cl determination in solid samples using plastic scintillators
This work reports a new approach for the determination of 36Cl in radioactive waste samples from nuclear decommissioning, wherein novel plastic scintillator (PS) materials were used for the concentration of 36Cl prior to the detection with scintillation counting. Different plastic scintillator (PS) materials were tested for their selective absorption and detection of 36Cl activity in solid samples. PS microspheres (PSm), cross-linked PSm (CPSm) and PS resin have been investigated. PS resin was identified as the most suitable material for 36Cl analysis. Pyrolysis and subsequent trapping of the volatile elements in a bubbler was used. The trapping solution was finally loaded onto a cartridge of the PS resin. Scintillation counting and ion chromatography were used to determine the activity concentration and the chemical recovery, respectively
A comparison of different approaches for the analysis of 36Cl in graphite samples
This study compares different approaches for the quantification of the massic activity of 36Cl in graphite samples. All approaches consisted of a combustion step in combination with a trapping solution to collect the volatile elements. Two different resins were used to separate 36Cl from the matrix (CL resin and PS resin). Liquid scintillation counting (LSC), scintillation counting (SC) and tandem inductively coupled plasma mass spectrometry (ICP-MS/MS) were used to quantify 36Cl activity. The chemical yield in all approaches was determined by means of ion chromatography (IC). In addition, the methods were applied to a real activated graphite sample