Natural Circulation in the ATUCHA-I PHWR Nuclear Power Plant

A systematic study of natural circulation (NC) in a postulated, varying primary mass inventory scenario at residual power fractions has been performed for a nuclear power plant operating in Argentina. It is a pressurized heavy water reactor, cooled and moderated by heavy water. The analysis seems particularly relevant at present, because a second nuclear power plant (NPP), of similar design and nearly 745 MWe, is now under finalization. NRC-RELAP5/MOD3.3 was the code used to perform the simulations. Results obtained are presented in the form of natural circulation flow maps. The trends obtained fit in the expected limits for integral test facilities representative of PWRs. In addition, the validity of a simplified analysis to scale single and two-phase core flow has been verified. A set of constants has been obtained, which permits predicting NC core mass flow rate (CMFR) for this NPP. Results are partially validated, for single-phase NC flow, using a documented plant transient, showing reasonable agreement. Also, the effect of pressurizer size on the predicted evolution curve in the NC flow map (NCFM) is discussed

Observations on development and anomalies in the appendicular skeleton of sea bass, Dicentrarchus labrax L. 1758, larvae and juveniles

The development of the fin skeleton has been studied in both the wild and hatchery sea bass, Dicentrarchus labrax L., larvae, in order to identify and define morphofunctional criteria for larval quality assessments. The cartilaginous and bony skeletal elements of the larvae were studied and standard length and notochord flexure recorded. Fin anomalies were present in reared larvae, whereas they were rare or absent in specimens from the wild. These anomalies were recognizable from the very beginning of skeletal development, indicating that environmental, genetic and broodstock management factors influence even the very early stages of larval development

‘A Slow Build-Up of a History of Kindness’: Exploring the Potential of Community-Led Housing in Alleviating Loneliness

This article explores the potential of community-led housing (CLH) in combatting loneliness, and represents a mixed-methods research project carried out from just before the beginning of the pandemic, through 2020. Methods comprised a nationwide quantitative online survey of members of CLH groups (N = 221 respondents from England and Wales), followed by five case studies of communities representing a range of different CLH models. This qualitative element comprised participant observation, and semi-structured interviews at each group. The article also considers data from a smaller research project carried out by the same team in July 2020, that aimed to capture the experience of the pandemic for CLH groups, and comprising an online questionnaire followed by 18 semi-structured interviews. We conclude that members of CLH projects are measurably less lonely than those with comparable levels of social connection in wider society, and that such benefits are achieved through combinations of multiple different elements that include physical design, social design and through social processes. Notably, not all aspects of communities that contribute positively are a result of explicit intentionality, albeit the concept is considered key to at least one of the models

Total Synthesis of Asparenydiol by Two Sonogashira Cross-Coupling Reactions Promoted by Supported Pd and Cu Catalysts

Asparenydiol, which is an important natural compound with potential pharmacological activities, was synthesized through two Sonogashira cross-coupling reactions catalyzed by supported Pd and Cu catalysts and by a Mitsunobu etherification. The optimization of the Sonogashira couplings allowed the use of catalysts supported on different matrices with good results in terms of catalytic efficiency and yields

Area under the curve of methotrexate and creatinine clearance are outcome-determining factors in primary CNS lymphomas

Although high-dose methotrexate (HD-MTX) is the most effective drug against primary CNS lymphomas (PCNSL), outcome-determining variables related to its administration schedule have not been defined. The impact on toxicity and outcome of the area under the curve (AUC(MTX)), dose intensity (DI(MTX)) and infusion rate (IR(MTX)) of MTX and plasmatic creatinine clearance (CL(crea)) was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-based combinations. Anticonvulsants were administered in 31 pts (69%). Age >60 years, anticonvulsant therapy, slow IR(MTX) (1100 micromol hl(-1) were independently associated with a better survival. Slow CL(crea) and high AUC(MTX) are favourable outcome-determining factors in PCNSL, while slow CL(crea) is significantly related to higher toxicity. AUC(MTX) significantly correlates with age, anticonvulsant therapy, IR(MTX), and DI(MTX). These findings, which seem to support the choice of an MTX dose >/=3 gm(-2) in a 4-6-h infusion, every 3-4 weeks, deserve to be assessed prospectively in future trials. MTX dose adjustments in patients with fast CL(crea) should be investigated