Experimental study of consistency degradation of different greases in mixed neutron and gamma radiation

Many of the moving components in accelerator and target environments require lubrication. Lubricants in such environments are exposed to high fluxes of secondary radiation, which originates from beam interactions with the target and from beam losses. The secondary radiation is a mix of components, which can include significant fractions of neutrons. Lubricants are radiation-sensitive polymeric materials. The radiation-induced modifications of their structure reduce their service lifetime and impose additional facility maintenance, which is complicated by the environmental radioactivity. The study of the lubricants radiation resistance is therefore necessary for the construction of new generation accelerators and target systems. Nevertheless, data collected in mixed radiation fields are scarce. Nine commercial greases were irradiated at a TRIGA Mark II Research Reactor to serve for the construction of new accelerator projects like the European Spallation Source (ESS) at Lund (Sweden) and Selective Production of Exotic Species (SPES) at Legnaro, (Italy). Mixed neutron and gamma doses ranging from 0.1MGy to 9.0MGy were delivered to the greases. For an experimental quantification of their degradation, consistency was measured. Two of the greases remained stable, while the others became fluid. Post-irradiation examinations evidence the cleavage of the polymeric structure as the dominant radiation effect. Dose and fluence limits for the use of each product are presented. Apart from the scientific significance, the results represent an original and useful reference in selecting radiation resistant greases for accelerator and target applications

Early use of etanercept for graft-versus-host disease after liver transplant: The importance of broad spectrum infective prophylaxis

Graft-versus-host-disease after orthotopic liver transplant is a rare and life-threatening complication. The diagnosis is challenging and usually confirmed by chimerism and skin biopsies. The most common cause of death is sepsis (60%), and broad-spectrum antibiotics and antifungal prophylaxis are strongly recommended. We present a case of a 61-year-old man with hepatocellular carcinoma and a previous history of metabolic and alcoholic cirrhosis who underwent orthotopic liver transplant. The immunosuppression regimen consisted of corticosteroids, calcineurin inhibitor, and mammalian target of rapamycin complex 1 inhibitor. Nine days after surgery, the patient developed leukopenia and skin rash. After confirmation of graft-versus-host disease by chimerism and skin biopsy, etanercept, a novel anti-tumor necrosis factor-alpha drug used for patients with hematologic and rheumatologic disease, was administrated. Unfortunately, no clinical improvements or bone marrow recovery were noted, and the patient had subsequent fatal sepsis due to Enterococcus faecium, Aspergillus fumigatus, and viral superinfection. There are no US Food and Drug Administration-approved treatments for graft-versus-host disease after orthotopic liver transplant. The main risk factors are recipients > 50 years old, patients with glucose intolerance, patients transplanted due to hepatocellular carcinoma, donor-recipient age difference of > 20 years, and any HLA-class I match. In accordance with the literature, we suggest early use of broad-spectrum antibiotics and antifungal drugs during etanercept treatment. In addition, because of substantially higher risk for severe sepsis, we strongly recommend adding an antiviral prophylaxis to prevent Cytomegalovirus reactivation or unexpected superinfection

Experimental Study of Materials Radiation Resistance in Reactor Mixed Fields for the construction of the SPES Facility at LNL

The Selective Production of Exotic Species (SPES) facility, now under construction at Legnaro National Laboratories of INFN, is a second-generation accelerator for the production of neutron-rich ion beams. the radioactive nuclear species are produced by fission of a 238U target, on which a 200 uA primary proton beam of 40 MeV energy impinges. Materials and components constituting the Target and Ion Source assembly and the Front-End supporting structure are subjected to serious radioactive damage due to intense neutron and photon fields present under operating conditions. In the framework of the SPES project, experimental campaigns aimed at testing the radiation hardness of critical materials and components of potential use in the construction were started. Irradiations were conducted in a reactor neutron and photon mixed field in order to reproduce, as close as possible, the actual environmental service conditions. Results obtained for different types of elastomeric materials used for construction of vacuum O-rings, as well as preliminary results obtained for lubricating oils and greases, are presented. Materials under consideration are both conventional ones as well as materials specifically developed for applications in the presence of ionizing radiation. The latter materials were previously tested mainly in gamma fields

Instrumental neutron activation analysis (INAA) and liquid chromatography (LC) coupled to high resolution mass spectrometry (HRMS) characterisation of sildenafil based products seized on the Italian illegal market

The commerce of illegal and counterfeit medicinal products on internet is a serious criminal problem. Drugs for erectile dysfunction such as phosphodiesterase type 5 inhibitor are the most commonly counterfeited medicines in Europe. The search of possible toxic chemical substances in seized products is needed. Moreover, the profiling of the material can be the source of relevant forensic information. For the first time a combined approach based on liquid chromatography (LC) coupled to high resolution mass spectrometry (HRMS) and instrumental neutron activation analysis (INAA) is proposed and tested, allowing characterisation of both authentic and illegal pharmaceuticals containing sildenafil seized in Italy. LC-HRMS allowed the detection and identification of unknown impurities not reported on labels in illegal products and the quantitation of the sildenafil. INAA showed to be suitable to provide both qualitative and quantitative information for forensic purposes on 23 elements, allowing discrimination between legal and illegal products