A comprehensive validation of very early rule-out strategies for non-ST-segment elevation myocardial infarction in emergency departments:protocol for a multicentre prospective cohort study

Introduction: Recent advances in troponin sensitivity enabled early and accurate judgement of ruling-out myocardial infarction, especially non-ST elevation myocardial infarction (NSTEMI) in emergency departments (EDs) with development of various prediction-rules and high-sensitive-troponin-based strategies (hs-troponin). Reliance on clinical impression, however, is still common, and it remains unknown which of these strategies is superior. Therefore, our objective in this prospective cohort study is to comprehensively validate the diagnostic accuracy of clinical impression-based strategies, prediction-rules and hs-troponin-based strategies for ruling-out NSTEMIs. Methods and analysis: In total, 1500 consecutive adult patients with symptoms suggestive of acute coronary syndrome will be prospectively recruited from five EDs in two tertiary-level, two secondary-level community hospitals and one university hospital in Japan. The study has begun in July 2018, and recruitment period will be about 1 year. A board-certified emergency physician will complete standardised case report forms, and independently perform a clinical impression-based risk estimation of NSTEMI. Index strategies to be compared will include the clinical impression-based strategy; prediction rules and hs-troponin-based strategies for the following types of troponin (Roche Elecsys hs-troponin T; Abbott ARCHITECT hs-troponin I; Siemens ADVIA Centaur hs-troponin I; Siemens ADVIA Centaur sensitive-troponin I). The reference standard will be the composite of type 1 MI and cardiac death within 30 days after admission to the ED. Outcome measures will be negative predictive value, sensitivity and effectiveness, defined as the proportion of patients categorised as low risk for NSTEMI. We will also evaluate inter-rater reliability of the clinical impression-based risk estimation. Ethics and dissemination: The study is approved by the Ethics Committees of the Kyoto University Graduate School and Faculty of Medicine and of the five hospitals where we will recruit patients. We will disseminate the study results through conference presentations and peer-reviewed journals

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

International audienceThe Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu’s boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid

Metabolism of benzo[a]pyrene to trans-7,8-dihydroxy-7,8- dihydrobenzo[a]pyrene by recombinant human cytochrome P450 1B1 and purified liver epoxide hydrolase

Recombinant human enzymes expressed in membranes obtained from Escherichia coli transformed with cytochrome P450 (P450) and NADPH-P450 reductase cDNAs were used to identify the human P450 enzymes that are most active in catalyzing the oxidative transformation of benzo[a]pyrene in vitro. Activation of benzo[a]pyrene to genotoxic products that cause induction of umu gene expression in Salmonella typhimurium NM2009 by P450 1A1 and P450 1B1 enzymes was found to be enhanced by inclusion of purified epoxide hydrolase (isolated from rat or human livers) with the reaction mixture. High- performance liquid chromatographic analysis showed that P450 1B1 catalyzed benzo[a]pyrene to trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene at level of ~3 nmol min-1 nmol of P450-1 only when epoxide hydrolase was present and P450 1A1 (with the hydrolase) was able to catalyze benzo[a]pyrene at one- tenth of the activity catalyzed by P450 1B1. Kinetic analysis showed that ratio of V(max) to K(m) for the formation of trans-7,8-dihydroxy-7,8- dihydrobenzo[a]pyrene in this assay system was 3.2-fold higher in CYP1B1 than in CYP1A1. Other human P450s (including P450s 1A2, 2E1, and 3A4) were found to have very low or undetectable activities toward the formation of trans- 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene. A reconstituted system containing purified P450 1B1, rabbit liver NADPH-P450 reductase, and human liver epoxide hydrolase was found to catalyze benzo[a]pyrene to trans-7,8-dihydroxy-7,8- dihydrobenzo[a]pyrene at a rate of 0.86 nmol min-1 nmol of P450-1; the activities were found to be largely dependent on the presence of sodium cholate in the system. These results suggest that P450 1B1 is a principal enzyme in catalyzing the oxidation of benzo[a]pyrene to trans-7,8-dihydroxy- 7,8-dihydrobenzo[a]pyrene and that the catalytic functions of P450 1B1 may determine the susceptibilities of individuals to benzo[a]-pyrene carcinogenesis

Development of Y2O3 dispersion strengthened Cu alloy using Cu6Y and Cu2O addition through the MA-HIP process

A copper-based material is the recent main trend of advanced heat sink materials for the solid divertor systems, providing an optimal combination of excellent mechanical strength and superior thermal conductivity under severe neutron irradiation environment. In particular, oxide dispersion strengthened Cu (ODS-Cu) alloy with yttrium oxide (Y2O3) nano-particles is one of the promising materials because of the lower influence of the particles on thermal conductivity and the higher resistance to coarsening of the particles due to their thermodynamic stability. The metal Y as the Y2O3 source has been used to fabricate ODS-Cu alloys in the previous work. In this study, we used the Cu6Y intermetallic compound as the new Y source material to form Y2O3 particles during mechanical alloying (MA) followed by hot isostatic pressing (HIP) process, and successfully fabricated ODS-Cu alloy with Y2O3 nano-particles using the Cu6Y compound. The effects of Cu2O addition in this process as the oxidant material were also investigated. Y2O3 nano-particles with typical size of 30 nm were successfully formed into the Cu intra-grains and around grain boundaries, and the density of the Y2O3 nano-particles increased by the Cu2O addition. Cu2O addition promoted the oxidation of Y from the Cu6Y compound, forming Y2O3 nano-particles