Novel Methods of Isotopic Separation of Lithium 6

Nuclear applications often require specific isotopes of an element with the right properties. An example is lithium, which has two isotopes that play a crucial role in the nuclear industry. Lithium-7 is commonly employed as a pH controller in the cooling systems of nuclear reactors, while lithium-6 is vital for tritium production. However, the natural abundance of lithium-6 is only 7.5%, which is insufficient to achieve a high breeding rate of tritium in technically feasible breeder blanket designs. Therefore, increasing the proportion of lithium-6 in any breeder blanket concept presents a significant challenge that needs to be addressed. Prior to the operation of any commercial fusion power plant, it is necessary to establish a facility capable of producing several tons of enriched lithium-6 per year. Currently, no such facility exists. This study explores the different possibility for lithium isotope separation, and assess their viability

The role of niobium carbides in the localised corrosion initiation of 20Cr-25Ni-Nb advanced gas-cooled reactor fuel cladding

The role of niobium carbide (NbC) inclusions in directing the initiation of localised corrosion in sensitised 20Cr-25Ni-Nb stainless steel is investigated using a range of in-situ scanning techniques, allowing visualisation of corrosion behaviour over multiple length scales. Volta potential mapping shows NbC inclusions are up to 30 mV noble to the matrix, while chromium-depleted grain boundaries are up to 65 mV less noble. Corrosion initiation, shown by scanning vibrating electrode technique to comprise highly localised anode sites, is observed at grain boundaries, adjacent to the location of NbC inclusion clusters which remain unaffected by anodic dissolution of the surrounding matrix

Growing Teratoma Syndrome: An Asian Woman with Immature Teratoma of Left Ovary After Chemotherapy

International audienceAims: Loss-of-function of the cardiac sodium channel NaV1.5 is a common feature of Brugada syndrome. Arrhythmias arise preferentially from the right ventricle (RV) despite equivalent NaV1.5 downregulation in the left ventricle (LV). The reasons for increased RV sensitivity to NaV1.5 loss-of-function mutations remain unclear. Because ventricular electrical activation occurs predominantly in the transmural axis, we compare RV and LV transmural electrophysiology to determine the underlying cause of the asymmetrical conduction abnormalities in Scn5a haploinsufficient mice (Scn5a+/-). Methods and results: Optical mapping and two-photon microscopy in isolated-perfused mouse hearts demonstrated equivalent depression of transmural conduction velocity (CV) in the LV and RV of Scn5a+/- vs. wild-type littermates. Only RV transmural conduction was further impaired when challenged with increased pacing frequencies. Epicardial dispersion of activation and beat-to-beat variation in activation time were increased only in the RV of Scn5a+/- hearts. Analysis of confocal and histological images revealed larger intramural clefts between cardiomyocyte layers in the RV vs. LV, independent of genotype. Acute sodium current inhibition in wild type hearts using tetrodotoxin reproduced beat-to-beat activation variability and frequency-dependent CV slowing in the RV only, with the LV unaffected. The influence of clefts on conduction was examined using a two-dimensional monodomain computational model. When peak sodium channel conductance was reduced to 50% of normal the presence of clefts between cardiomyocyte layers reproduced the activation variability and conduction phenotype observed experimentally. Conclusions: Normal structural heterogeneities present in the RV are responsible for increased vulnerability to conduction slowing in the presence of reduced sodium channel function. Heterogeneous conduction slowing seen in the RV will predispose to functional block and the initiation of re-entrant ventricular arrhythmias

Practical Issues for Atom Probe Tomography Analysis of III-Nitride Semiconductor Materials.

Various practical issues affecting atom probe tomography (APT) analysis of III-nitride semiconductors have been studied as part of an investigation using a c-plane InAlN/GaN heterostructure. Specimen preparation was undertaken using a focused ion beam microscope with a mono-isotopic Ga source. This enabled the unambiguous observation of implantation damage induced by sample preparation. In the reconstructed InAlN layer Ga implantation was demonstrated for the standard "clean-up" voltage (5 kV), but this was significantly reduced by using a lower voltage (e.g., 1 kV). The characteristics of APT data from the desorption maps to the mass spectra and measured chemical compositions were examined within the GaN buffer layer underlying the InAlN layer in both pulsed laser and pulsed voltage modes. The measured Ga content increased monotonically with increasing laser pulse energy and voltage pulse fraction within the examined ranges. The best results were obtained at very low laser energy, with the Ga content close to the expected stoichiometric value for GaN and the associated desorption map showing a clear crystallographic pole structure.F.T. would like to thank David A. Nicol for his kind help. The European Research Council has provided financial support under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 279361 (MACONS).This is the author accepted manuscript. The final version is available from Cambridge University Press via http://dx.doi.org/10.1017/S143192761500042

Seasonal temperature trends on the Spanish mainland: A secular study (1916–2015)

Trends in seasonal mean values of maximum and minimum temperature are analysed in the Spanish mainland from the new MOTEDAS_century database. This new data set has been developed combining the digitalized archives from the Spanish Meteorological Agency (AEMET) with information retrieved from Annual Books published by the former Meteorological Agency dating back to 1916, and covers the period 1916–2015. In all four seasons, mean seasonal temperature of maximum (Tmax) and minimum (Tmin) increased. The raising occurred in two main pulses separated by a first pause around the middle of the 20th century, but differed among seasons and also between maximum and minimum temperature. Analysis of the percentage of land affected by significant trends in maximum temperature reveals two increasing phases in spring and summer for Tmax, and in spring, summer, and autumn for Tmin. However, winter Tmax only rose during the recent decades, and autumn Tmax in the first decades. Negative significant trends were found in extended areas in spring Tmax, and in spring, autumn, and summer Tmin, confirming the first pause around the 1940's–1960's. Trends of seasonal mean values of Tmax and Tmin are not significant for at least the last 25–35 years of the study period, depending on the season. The areas under significant positive trend are usually more extended for Tmin than Tmax at any season and period. Areas with significant trend expand and contract in time according to two spatial gradients: south-east to north-west (east-west) for Tmax, and west to east for Tmin. We hypothesize a relationship between atmospheric prevalent advection and relief as triggering factors to understand spatial and temporal differences in seasonal temperatures at regional scale during the 20th century in the Iberian Peninsula

The emotional effects on professional interpreters of interpreting palliative care conversations for adult patients : a rapid review

Background: Professional interpreters working in palliative contexts improve patient care. Whilst literature identifies psychological distress in other healthcare professionals, research into emotional effects on professional interpreters in this highly emotive setting is limited. Isolating emotional responses may enable targeted interventions to enhance interpreter use and improve wellbeing. Timely evidence is needed to urgently familiarise the profession with issues faced by these valuable colleagues, to affect practice. Aim: Describe the emotional effects on professional interpreters of interpreting adult palliative care conversations. Collate recommendations to mitigate negative emotional effects. Design: We performed a rapid review of studies identifying emotional effects on professional interpreters of interpreting adult palliative conversations. Rapid review chosen to present timely evidence to relevant stakeholders in a resource-efficient way. Thematic analysis managed using NVivo. Quality appraisal evaluated predominantly using CASP checklists. Reported using PRISMA guidelines. PROSPERO registration CRD42022301753. Data sources: Articles available in English on PubMed [1966–2021], MEDLINE [1946–2021], EMBASE [1974–2021], CINAHL [1981–2021] and PsycINFO [1806–2021] in December 2021. Results: Eleven articles from the USA (5), Australia (3), Canada (2) and UK (1). Eight interview-based, two online surveys and one quality improvement project. Themes included (1) Identifying diversity of emotional effects: emotions including stress, discomfort, loneliness. (2) Identifying factors affecting interpreters’ emotional responses: impact of morals, culture and role expectations; working with patients and families; interpreter experience and age. (3) Recommendations to mitigate negative emotional effects: pre-briefing, debriefing and interpreter/provider training. Conclusion: Professional interpreters experience myriad emotional responses to palliative conversations. Role clarity, collaborative working and formal training may alleviate negative effects