Development of a viable route for lithium-6 supply of DEMO and future fusion power plants

In the European DEMO program, the design development of a demonstration power plant (DEMO) is currently in its pre-conceptual phase. In DEMO, breeding blankets will use large quantities of lithium, enriched in the isotope lithium-6 (6Li), for breeding the tritium needed to feed the DT fusion reaction. Unfortunately, enriched lithium is commercially not available in the required quantities, which is threatening the success of future power plant applications of nuclear fusion. Even if the manufacturing of the breeding blankets is still two decades ahead of us, it is now mandatory to address the topic of lithium-6 supply and to make sure that a viable supply (and reprocessing) route is available when needed. This paper presents an unbiased systems engineering approach assessing a number of available lithium isotope separation methods by defining requirements, rating them systematically and finally calculating a ranking number expressing the value of different methods. As a result, we suggest using a chemical exchange method based on a lithium amalgam system, but including some important improvements leading to a more efficient and ‘clean’ process (the ICOMAX process) in comparison with the formerly used COLEX process. Furthermore, by modelling activities and experiments in the KIT mercury laboratory (HgLab Karlsruhe), it is shown which work has to be done in the next years to make sure that the technical-scale process is available in time to supply DEMO and future fusion power plants by middle of the 21st century

The pre-concept design of the DEMO tritium, matter injection and vacuum systems

In the Pre-Concept Design Phase of EU-DEMO, the work package TFV (Tritium – Matter Injection – Vacuum) has developed a tritium self-sufficient three-loop fuel cycle architecture. Driven by the need to reduce the tritium inventory in the systems to an absolute minimum, this requires the continual recirculation of gases in loops without storage, avoiding hold-ups of tritium in each process stage by giving preference to continuous over batch technologies, and immediate use of tritium extracted from tritium breeding blankets. In order to achieve this goal, a number of novel concepts and technologies had to be found and their principal feasibility to be shown. This paper starts from a functional analysis of the fuel cycle and introduces the results of a technology survey and ranking exercise which provided the prime technology candidates for all system blocks. The main boundary conditions for the TFV systems are described based on which the fuel cycle architecture was developed and the required operational windows of all subsystems were defined. To validate this, various R&D lines were established, selected results of which are reported, together with the key technology developments. Finally, an outlook towards the Concept Design Phase is given

Predicting hospital stay, mortality and readmission in people admitted for hypoglycaemia: prognostic models derivation and validation

Aims/hypothesis: Hospital admissions for hypoglycaemia represent a significant burden on individuals with diabetes and have a substantial economic impact on healthcare systems. To date, no prognostic models have been developed to predict outcomes following admission for hypoglycaemia. We aimed to develop and validate prediction models to estimate risk of inpatient death, 24 h discharge and one month readmission in people admitted to hospital for hypoglycaemia. Methods: We used the Hospital Episode Statistics database, which includes data on all hospital admission to National Health Service hospital trusts in England, to extract admissions for hypoglycaemia between 2010 and 2014. We developed, internally and temporally validated, and compared two prognostic risk models for each outcome. The first model included age, sex, ethnicity, region, social deprivation and Charlson score (‘base’ model). In the second model, we added to the ‘base’ model the 20 most common medical conditions and applied a stepwise backward selection of variables (‘disease’ model). We used C-index and calibration plots to assess model performance and developed a calculator to estimate probabilities of outcomes according to individual characteristics. Results: In derivation samples, 296 out of 11,136 admissions resulted in inpatient death, 1789/33,825 in one month readmission and 8396/33,803 in 24 h discharge. Corresponding values for validation samples were: 296/10,976, 1207/22,112 and 5363/22,107. The two models had similar discrimination. In derivation samples, C-indices for the base and disease models, respectively, were: 0.77 (95% CI 0.75, 0.80) and 0.78 (0.75, 0.80) for death, 0.57 (0.56, 0.59) and 0.57 (0.56, 0.58) for one month readmission, and 0.68 (0.67, 0.69) and 0.69 (0.68, 0.69) for 24 h discharge. Corresponding values in validation samples were: 0.74 (0.71, 0.76) and 0.74 (0.72, 0.77), 0.55 (0.54, 0.57) and 0.55 (0.53, 0.56), and 0.66 (0.65, 0.67) and 0.67 (0.66, 0.68). In both derivation and validation samples, calibration plots showed good agreement for the three outcomes. We developed a calculator of probabilities for inpatient death and 24 h discharge given the low performance of one month readmission models. Conclusions/interpretation: This simple and pragmatic tool to predict in-hospital death and 24 h discharge has the potential to reduce mortality and improve discharge in people admitted for hypoglycaemia

Segurança do paciente no uso de medicamentos após a alta hospitalar: estudo exploratório1

No Brasil, são escassos os estudos sobre estratégias para a segurança do paciente no processo de uso de medicamentos após a alta hospitalar, o que dificulta o conhecimento sobre a atuação de hospitais brasileiros nessa área. Neste artigo, buscou-se compreender a dinâmica e os desafios do cuidado fornecido ao paciente pela equipe hospitalar, visando à segurança no processo de uso de medicamentos após a alta hospitalar. Realizou-se pesquisa exploratória por meio de entrevistas com médicos, enfermeiros, farmacêuticos e assistentes sociais do Hospital Universitário da Universidade de São Paulo. Foram pesquisadas as atividades de cuidado com a farmacoterapia durante e após a hospitalização, incluindo o acesso a medicamentos após alta, a existência de articulação do hospital com outros serviços de saúde, e barreiras para desenvolver essas atividades. A principal estratégia adotada é a orientação de alta, realizada de forma estruturada, principalmente para cuidadores de pacientes pediátricos. Em situações específicas, ocorre mobilização da equipe para viabilização do acesso a medicamentos prescritos na alta. Reconciliação medicamentosa está em fase de implantação, e visita domiciliar é realizada apenas para pacientes críticos com problemas de locomoção. As principais barreiras identificadas foram insuficiência de recursos humanos e falta de tecnologias de informação. Conclui-se que são desenvolvidas algumas estratégias, porém com limitações e sem articulação adequada com outros serviços de saúde para a continuidade do cuidado. Isto sugere a necessidade de concentração de esforços para transpor as barreiras identificadas, contribuindo para a segurança do paciente na interface entre hospital, atenção básica e domicílio

Cryogenic vacuum considerations for future gravitational wave detectors

In recent years, gravitational wave observatories have conquered the world science scene due to their unprecedented capability to observe astrophysical signals. Those first observations opened up multimessenger astronomy and called for a tremendous R&D effort to improve the sensitivity of future detectors. One of the many issues to be solved, not to affect the desired sensitivity, is the noise induced by the use of room temperature mirrors, especially for the low-frequency detection range. The use of cryogenic mirrors to reduce such a noise source has been individuated as a viable solution to obtain the desired sensitivity at low frequency. Cryogenically cooled mirrors, routinely operating at 10 K, present a number of extraordinary challenges, one being the cryogenic vacuum system hosting the cold mirrors. Gases composing the residual vacuum will tend to cryosorb and build a contaminant ice layer (“frost”) on the mirror surface. Depending on such ice layer thickness, various unwanted detrimental effects may occur affecting mirror performances. This paper analyzes the consequences of hosting a cryogenically cooled mirror in a vacuum system and sets new limits for an acceptable operating pressure to avoid frost formation in a given period of continuous data taking. Since ice formation can be reduced but not avoided, we analyze potential mitigation methods to cure such a phenomenon. Thermal and nonthermal methods are analyzed and compared. Electron stimulated desorption is also considered as an alternative method to desorb the ice layer on mirrors. Finally, we briefly discuss further studies needed to validate the various methods with special care on their effects on the mirror perfection and optical properties

Development and Validation of a Cardiovascular Risk Assessment Model in Patients With Established Coronary Artery Disease

none13could contribute to the prevention of recurrent cardiovascular events. The purpose of the present study was to develop and validate risk prediction models for various cardiovascular end points in the EURopean trial On reduction of cardiac events with Perindopril in stable coronary Artery disease (EUROPA) database, consisting of 12,218 patients with established coronary artery disease, with a median follow-up of 4.1 years. Cox proportional hazards models were used for model development. The end points examined were cardiovascular mortality, noncardiovascular mortality, nonfatal myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention, resuscitated cardiac arrest, and combinations of these end points. The performance measures included Nagelkerke’s R2, time-dependent area under the receiver operating characteristic curves, and calibration plots. Backward selection resulted in a prediction model for cardiovascular mortality (464 events) containing age, current smoking, diabetes mellitus, total cholesterol, body mass index, previous myocardial infarction, history of congestive heart failure, peripheral vessel disease, previous revascularization, and previous stroke. The model performance was adequate for this end point, with a Nagelkerke R2 of 12%, and an area under the receiver operating characteristic curve of 0.73. However, the performance of models constructed for nonfatal and combined end points was considerably worse, with an area under the receiver operating characteristic curve of about 0.6. In conclusion, in patients with established coronary artery disease, the risk of cardiovascular mortality during longer term follow-up can be adequately predicted using the clinical characteristics available at baseline. However, the prediction of nonfatal outcomes, both separately and combined with fatal outcomes, poses major challenges for clinicians and model developers. 2013 Elsevier Inc. All rights reserved.noneLinda Battes; Rogier Barendse; Ewout W. Steyerberg; Maarten L. Simoons; Jaap W. Deckers; Daan Nieboer; Michel Bertrand; Roberto Ferrari; Willem J. Remme; Kim Fox; Johanna J.M. Takkenberg; Eric Boersma; and Isabella Kardys;Linda, Battes; Rogier, Barendse; Ewout W., Steyerberg; Maarten L., Simoons; Jaap W., Deckers; Daan, Nieboer; Michel, Bertrand; Ferrari, Roberto; Willem J., Remme; Kim, Fox; Johanna J. M., Takkenberg; Eric, Boersma; Isabella, Kardy