Organic matter from Artic sea ice loss alters bacterial community structure and function

Continuing losses of multi-year sea ice (MYI) across the Arctic are resulting in first-year ice (FYI) dominating the Arctic ice pack. Melting FYI provides a strong seasonal pulse of dissolved organic matter (DOM) into surface waters; however, the biological impact of this DOM input is unknown. Here we show that DOM additions cause significant and contrasting changes in under-ice bacterioplankton abundance, production and species composition. Utilization of DOM was influenced by molecular size, with 10-100 kDa and >100 kDa DOM fractions promoting rapid growth of particular taxa, while uptake of sulfur and nitrogen-rich low molecular weight organic compounds shifted bacterial community composition. These results demonstrate the ecological impacts of DOM released from melting FYI, with wideranging consequences for the cycling of organic matter across regions of the Arctic Ocean transitioning from multi-year to seasonal sea ice as the climate continues to warm

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

Direct Catalytic Asymmetric Amination of Aldehydes: Synthesis of Evans Oxazolidinones and a-Amino Acids

ORGANIC CHEMISTRY 16:511 -- 517 (2003) # 2003 Data Trace Publishing Company CCC 1431-9268 O O O O H O Me OH O O OH NH 2 OMe (PMPNH 2 ) O Ar H O OH Ar NHPMP O OH O Me O DMF, rt 100% 93% ee DMSO 97% 96% ee DMSO 92% >95% de; >99% ee (1) (2) (4) O H O H O OH Me H (3) DMF, +4 C 80% C 6 H 6 p-TsOH + + Scheme 1. Some representative proline-catalyzed asymmetric reactions. N R X Y COOH Y X N R COOH O R X YH O R N H - H 2 O + H 2 O XY: C=O, C=N, C=C, N=N Scheme 2. The enamine catalysis cycle. (-amination, vide infra). Subsequent hydrolysis of the resulting iminium ion liberates the product and regenerates the active catalyst. It is important to note that proline must remain either unreactive towards X Y or react with the electrophile in a reversible fashion. O N O Ph Ph Cu Ph Ph (OTf) 2 N O O O O EtOOC O O Ph NMe 2 OTMS N N O 2 S O 2 S Mg Ph Ph N O O N NHCBz O Cbz O Ph NMe 2 Me O N Boc NHBoc N O EtOOC O NHCbz O O N O O O BocN NHBoc 86 % 20 mol% p-TosNHMe 85% (1) (2) (3) 7