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中性子照射場として中核を担ってきた材料試験炉(Japan Materials Testing Reactor: JMTR)の廃止に伴い、軽水炉の一層の安全性、信頼性・効率性向上のための技術開発や革新的な原子炉開発に必要な国内照射場が喪失され、照射試験炉の運転技術や照射技術の継承や人材育成も困難な状況となった。こうした課題に対処するため、代替手段として中性子照射場を海外炉に求めた照射試験の実施に係る検討を行った。「ポーランド国立原子力研究センターと日本原子力研究開発機構との間の試験研究炉の研究開発のための共同研究取決め」に基づきポーランド国立原子力研究センター(NCBJ)が所有するMARIA炉(出力30MW)を中性子照射場として、JMTRの有する照射技術の一つである温度制御システムを導入した照射試験の実施可否を検討した。その結果、JMTRの設計・製作基準に則って製作済であったキャプセルに対し改造を施すことで照射試験の実現が可能である見通しが得られた。改造後に浸透探傷検査、絶縁導通試験及びキャプセルの使用温度である室温$\sim$300$^{\circ}$Cの範囲における動作試験等を実施し、良好な結果が得られ、MARIA炉への輸送前準備を完了した。, Because of the decommission of the Japan Materials Testing Reactor (JMTR), the domestic neutron irradiation facility, which had played a central role in the development of innovative nuclear reactors and the development of technologies to further improve the safety, reliability, and efficiency of light water reactors, was lost. Therefore, it has become difficult to pass on the operation techniques of the irradiation test reactors and irradiation technologies, and to train human resources. In order to cope with these issues, we conducted a study on the implementation of irradiation tests using overseas reactors as neutron irradiation sites as an alternative method. Based on the "Arrangement between the National Centre for Nuclear Research and the Japan Atomic Energy Agency for Cooperation in Research and Development on Testing Reactor," the feasibility of conducting an irradiation test at the MARIA reactor (30 MW) owned by the National Centre for Nuclear Research (NCBJ) using the temperature control system, which is one of the JMTR irradiation technologies, was examined. As a result, it was found that the irradiation test was possible by modifying the ready-made capsule manufactured in accordance with the design and manufacturing standards of the JMTR. After the modification, a penetration test, an insulation continuity test, and an operation test in the range of room temperature to 300$^{\circ}$C, which is the operating temperature of the capsule, were conducted and favorable results were obtained. We have completed the preparations prior to transport to the MARIA reactor.

International audience; The minimization of proliferation risks for research reactors necessitates the reduction of the enrichment of the uranium fuels. In the EU, this conversion from high to low enriched uranium has already begun and is currently on its way towards the qualification phase. This concerns both medium and high power research reactors. Neither for medium nor for high power research reactors are off-the-shelf low enriched uranium fuel elements available. Indeed, introducing a new type of fuel element in a research reactor implies the conservation or improvement of both safety and performance on one of a kind units within specific safety legislation. The H2020 European LEU-FOREvER Project (2017-2021), associating major actors of the European research reactors field –Areva-NP, CEA, Centrum výzkumu Řež, ILL, NCBJ, SCK∙CEN, TechnicAtome, TUM, aims to foster the development of sustainable and innovative low enriched uranium fuel elements for the whole spectrum of European research reactors.

Background: The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate viral hepatitis by 2030. Although no virological cure exists for hepatitis B virus (HBV) infection, existing therapies to control viral replication and prophylaxis to minimise mother-to-child transmission make elimination of HBV feasible. We aimed to estimate the national, regional, and global prevalence of HBsAg in the general population and in the population aged 5 years in 2016, as well as coverage of prophylaxis, diagnosis, and treatment. Methods: In this modelling study, we used a Delphi process that included a literature review in PubMed and Embase, followed by interviews with experts, to quantify the historical epidemiology of HBV infection. We then used a dynamic HBV transmission and progression model to estimate the country-level and regional-level prevalence of HBsAg in 2016 and the effect of prophylaxis and treatment on disease burden. Findings: We developed models for 120 countries, 78 of which were populated with data approved by experts. Using these models, we estimated that the global prevalence of HBsAg in 2016 was 3·9% (95% uncertainty interval [UI] 3·4–4·6), corresponding to 291 992 000 (251 513 000–341 114 000) infections. Of these infections, around 29 million (10%) were diagnosed, and only 4·8 million (5%) of 94 million individuals eligible for treatment actually received antiviral therapy. Around 1·8 (1·6–2·2) million infections were in children aged 5 years, with a prevalence of 1·4% (1·2–1·6). We estimated that 87% of infants had received the three-dose HBV vaccination in the first year of life, 46% had received timely birth-dose vaccination, and 13% had received hepatitis B immunoglobulin along with the full vaccination regimen. Less than 1% of mothers with a high viral load had received antiviral therapy to reduce mother-to-child transmission. Interpretation: Our estimate of HBV prevalence in 2016 differs from previous studies, potentially because we took into account the effect of infant prophylaxis and early childhood vaccination, as well as changing prevalence over time. Although some regions are well on their way to meeting prophylaxis and prevalence targets, all regions must substantially scale-up access to diagnosis and treatment to meet the global targets. Funding: John C Martin Foundation. © 2018 Elsevier Ltd

Item does not contain fulltext Gelatin methacrylate (GelMA) is an inexpensive, photocrosslinkable, cell-responsive hydrogel which has drawn attention for a wide range of tissue engineering applications. The potential of GelMA scaffolds was demonstrated to be tunable for different tissue engineering (TE) applications through modifying the polymer concentration, methacrylation degree, or UV light intensity. Despite the promising results of GelMA hydrogels in tissue engineering, the influence of polymer concentration for bone tissue engineering (BTE) scaffolds was not established yet. Thus, in this study, we have demonstrated the effect of polymer concentration in GelMA scaffolds on osteogenic differentiation. We prepared GelMA scaffolds with 5 and 10% polymer concentrations and characterized the scaffolds in terms of porosity, pore size, swelling characteristics, and mechanical properties. Subsequent to the scaffolds characterization, the scaffolds were seeded with bone marrow derived rat mesenchymal stem cells and cultured in osteogenic media to evaluate the possible osteogenic differentiation effect exerted by the polymer concentration. After 7, 14, 21, and 28 days, DNA content, calcium deposition, and alkaline phosphatase (ALP) activity of scaffolds were evaluated quantitatively by colorimetric bioassays. Furthermore, the distribution of the calcium deposition within the scaffolds was attained qualitatively and quantitatively by microcomputer tomography (microCT). Our data suggest that GelMA hydrogels prepared with 5% polymer concentration has promoted homogeneous extracellular matrix calcification and it is a great candidate for BTE applications. (c) 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 201-209, 2018.

International audience

Item does not contain fulltext Calcium phosphate (CaP) coatings can enhance the performance of bone implants in compromised conditions, such as osteoporosis. Therefore, this study compared non-coated vs. CaP-coated (n = 8) titanium implants in osteoporotic ovariectomized (OVX) rats. Bone volume (BV) was assessed using micro-computer tomography (micro-CT) and three-dimensional (3D) histology, in three zones from the implant surface. Bone remodeling was assessed using fluorochrome labels and osteoclast staining. Micro-CT and 3D histology showed a BV reduction in OVX animals, of respectively 22.4 and 10.5%. BV was significantly increased inside all zones around CaP coatings, especially in the inner zone of the OVX animals. Fluorochrome labels were predominantly seen when the coating was applied. Osteoclasts were mainly found in the area remote from the surface of non-coated implants in control animals. For the coated implants, osteoclasts were distributed evenly, and present in direct vicinity of the surface. In conclusion, 3D histology is a suitable technique to obtain data and insight into bone architecture around implants at relatively high resolution. Bone formation was significantly reduced in osteoporotic animals. CaP coatings resulted in a higher BV directly around implants installed in osteoporotic animals, enhanced turnover, and a shift of remodeling activity toward the implant surface. (c) 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3463-3473, 2015.

Over the past years a number of studies have described the instability of the pigment cadmium yellow (CdS). In a previous paper we have shown how cadmium sulfide on paintings by James Ensor oxidizes to CdSO(4)·H(2)O. The degradation process gives rise to the fading of the bright yellow color and the formation of disfiguring white crystals that are present on the paint surface in approximately 50 μm sized globular agglomerations. Here, we study cadmium yellow in the painting "Flowers in a blue vase" by Vincent van Gogh. This painting differs from the Ensor case in the fact that (a) a varnish was superimposed onto the degraded paint surface and (b) the CdS paint area is entirely covered with an opaque crust. The latter obscures the yellow color completely and thus presents a seemingly more advanced state of degradation. Analysis of a cross-sectioned and a crushed sample by combining scanning microscopic X-ray diffraction (μ-XRD), microscopic X-ray absorption near-edge spectroscopy (μ-XANES), microscopic X-ray fluorescence (μ-XRF) based chemical state mapping and scanning microscopic Fourier transform infrared (μ-FT-IR) spectrometry allowed unravelling the complex alteration pathway. Although no crystalline CdSO(4) compounds were identified on the Van Gogh paint samples, we conclude that the observed degradation was initially caused by oxidation of the original CdS pigment, similar as for the previous Ensor case. However, due to the presence of an overlying varnish containing lead-based driers and oxalate ions, secondary reactions took place. In particular, it appears that upon the photoinduced oxidation of its sulfidic counterion, the Cd(2+) ions reprecipitated at the paint/varnish interface after having formed a complex with oxalate ions that themselves are considered to be degradation products of the resin and/or oil in the varnish. The SO(4)(2-) anions, for their part, found a suitable reaction partner in Pb(2+) ions stemming from a dissolved lead-based siccative that was added to the varnish to promote its drying. The resulting opaque anglesite compound in the varnish, in combination with the underlying CdC(2)O(4) layer at the paint/varnish interface, account for the orange-gray crust that is disfiguring the painting on a macroscopic level. In this way, the results presented in this paper demonstrate how, through a judicious combined use of several microanalytical methods with speciation capabilities, many new insights can be obtained from two minute, but highly complex and heterogeneous paint samples.