An additional deep-water mass in Drake Passage as revealed by 3He data

We present 3He data froma repeat section across Drake Passage, fromthree sections off the South American continent in the Pacific, at 28?S, 35?S, and 43?S, and fromthree sections in the Atlantic, eastward of the Malvinas, close to 35?W, and near the Greenwich Meridian. In Drake Passage, a distinct high-3He signal is observed that is centered just above the boundary of the Lower and the Upper Circumpolar Deep Water (LCDW, UCDW), and is concentrated towards the northern continental slope. 3He concentrations in the Antarctic Circumpolar Current (ACC) upstream of Drake Passage (World Ocean Circulation Experiment section P19 at 88?W) are markedly lower than those found in Drake Passage, and a regional source of primordial helium in the path of the ACC that might cause the high-3He feature can be ruled out. We explain the feature by addition of high-3He waters present at the 43?S Pacific section. This supports a previous, similar interpretation of a low-salinity anomaly in Drake Passage (Naveira Garabato et al., Deep- Sea Research I 49 (2002) 681), that is strongly related to the high-3He feature. Employing multiparameter water mass analysis (including 3He as a parameter), we find that deep waters as met at the 43?S Pacific section, flowing south along the South American continental slope, contribute substantially to the ACC waters in Drake Passage (fractions exceed 50% locally). Lesser, but laterally more extended contributions are found east of the Malvinas, and still smaller ones are present at 35?W and at the Greenwich Meridian. Using velocity measurements from one of the two Drake Passage sections, we estimate the volume transport of these waters to be 7.071.2 Sv, but the average transport may be somewhat lower as the other realization had a less pronounced signal. The enhanced 3He signature in Drake Passage is essentially confined north of the Polar Front. Further downstreamthe signature crosses this front, to the extent that at 35?W the contributions south and north of it are of similar magnitude. At the same time, the 3He levels north of the front are reduced due to a substantial admixture of low-3He North Atlantic Deep Water, such that 3He becomes highest south of the front. The flow of Southeast Pacific deep slope waters entering the ACC constitutes the predominant exit pathway of the primordial helium released in the deep Pacific, and represents a considerable fraction of the deep water return flow fromthe Pacific into the ACC. Therefore and also because the density range of the added deep slope waters is intermediate between those of UCDW and LCDW, they must be considered a distinct water mass. r 2003 Elsevier Ltd. All rights reserved

Electrical semiconduction modulated by light in a cobalt and naphthalene diimide metal-organic framework

Metal–organic frameworks (MOFs) have emerged as an exciting class of porous materials that can be structurally designed by choosing particular components according to desired applications. Despite the wide interest in and many potential applications of MOFs, such as in gas storage, catalysis, sensing and drug delivery, electrical semiconductivity and its control is still rare. The use and fabrication of electronic devices with MOF-based components has not been widely explored, despite significant progress of these components made in recent years. Here we report the synthesis and properties of a new highly crystalline, electrochemically active, cobalt and naphthalene diimide-based MOF that is an efficient electrical semiconductor and has a broad absorption spectrum, from 300 to 2500 nm. Its semiconductivity was determined by direct voltage bias using a four-point device, and it features a wavelength dependant photoconductive–photoresistive dual behaviour, with a very high responsivity of 2.5 × 105 A W−1

The Dapagliflozin and Prevention of Adverse-outcomes in Heart Failure (DAPA-HF) trial: baseline characteristics

The aims of this study were to: (i) report the baseline characteristics of patients enrolled in the Dapagliflozin And Prevention of Adverse-outcomes in Heart Failure (DAPA-HF) trial, (ii) compare DAPA-HF patients to participants in contemporary heart failure (HF) registries and in other recent HF trials, and (iii) compare individuals with diabetes, pre-diabetes and a normal glycated haemoglobin (HbA1c) in DAPA-HF. Adults with HF in New York Heart Association functional class ≥ II, a left ventricular ejection fraction ≤ 40%, an elevated N-terminal pro-B-type natriuretic peptide concentration and receiving standard treatment were eligible for DAPA-HF, which is comparing dapagliflozin 10 mg once daily to matching placebo. In patients without a history of diabetes, previously undiagnosed diabetes was defined as a confirmed HbA1c ≥ 6.5%. Among patients without known or undiagnosed diabetes, pre-diabetes was defined as a HbA1c ≥ 5.7% The remainder of patients, with a HbA1c < 5.7%, were defined as normoglycaemic. Of the 4774 patients (mean age 66 years; 23% women) randomized, 42% had known diabetes and 3% undiagnosed diabetes. Of the remainder, 67% had pre-diabetes and 33% normal HbA1c. Overall, DAPA-HF patients were generally similar to those in recent registries and in relevant trials and had high levels of background therapy: 94% angiotensin-converting enzyme inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitor, 96% beta-blocker, and 71% mineralocorticoid receptor antagonist; 26% had a defibrillator. Patients with diabetes had worse HF status, more co-morbidity, and greater renal impairment but received similar HF therapy. Patients with diabetes received non-insulin hypoglycaemic therapy alone in 49%, insulin alone in 11%, both in 14%, and none in 26%. Patients randomized in DAPA-HF were similar to those in other contemporary HF with reduced ejection fraction (HFrEF) registries and trials. These patients were receiving recommended HFrEF therapy and those with diabetes were also treated with conventional glucose-lowering therapy. Consequently, DAPA-HF will test the incremental efficacy and safety of dapagliflozin in HFrEF patients with and without diabetes

Effect of dapagliflozin in DAPA-HF according to background glucose-lowering therapy

Objective: To determine whether the benefits of dapagliflozin in patients with heart failure and reduced ejection fraction (HFrEF) and type 2 diabetes in the Dapagliflozin And Prevention of Adverse-Outcomes in Heart Failure trial (DAPA-HF) varied by background glucose-lowering therapy (GLT). Research Design and Methods: We examined the effect of study treatment by the use or not of GLT and by GLT classes and combinations. The primary outcome was a composite of worsening HF (hospitalization or urgent visit requiring intravenous therapy) or cardiovascular death. Results: In the 2,139 type 2 diabetes patients, the effect of dapagliflozin on the primary outcome was consistent by GLT use or no use (hazard ratio 0.72 [95% CI 0.58–0.88] versus 0.86 [0.60–1.23]; interaction P = 0.39) and across GLT classes. Conclusions: In DAPA-HF, dapagliflozin improved outcomes irrespective of use or no use of GLT or by GLT type used in patients with type 2 diabetes and HFrEF

Experiences of the Data Monitoring Committee for the RECOVERY trial, a large-scale adaptive platform randomised trial of treatments for patients hospitalised with COVID-19

Abstract: Aim: To inform the oversight of future clinical trials during a pandemic, we summarise the experiences of the Data Monitoring Committee (DMC) for the Randomised Evaluation of COVID therapy trial (RECOVERY), a large-scale randomised adaptive platform clinical trial of treatments for hospitalised patients with COVID-19. Methods and findings: During the first 24 months of the trial (March 2020 to February 2022), the DMC oversaw accumulating data for 14 treatments in adults (plus 10 in children) involving > 45,000 randomised patients. Five trial aspects key for the DMC in performing its role were: a large committee of members, including some with extensive DMC experience and others who had broad clinical expertise; clear strategic planning, communication, and responsiveness by the trial principal investigators; data collection and analysis systems able to cope with phases of very rapid recruitment and link to electronic health records; an ability to work constructively with regulators (and other DMCs) to address emerging concerns without the need to release unblinded mortality results; and the use of videoconferencing systems that enabled national and international members to meet at short notice and from home during the pandemic when physical meetings were impossible. Challenges included that the first four treatments introduced were effectively ‘competing’ for patients (increasing pressure to make rapid decisions on each one); balancing the global health imperative to report on findings with the need to maintain confidentiality until the results were sufficiently certain to appropriately inform treatment decisions; and reliably assessing safety, especially for newer agents introduced after the initial wave and in the small numbers of pregnant women and children included. We present a series of case vignettes to illustrate some of the issues and the DMC decision-making related to hydroxychloroquine, dexamethasone, casirivimab + imdevimab, and tocilizumab. Conclusions: RECOVERY’s streamlined adaptive platform design, linked to hospital-level and population-level health data, enabled the rapid and reliable assessment of multiple treatments for hospitalised patients with COVID-19. The later introduction of factorial assessments increased the trial’s efficiency, without compromising the DMC’s ability to assess safety and efficacy. Requests for the release of unblinded primary outcome data to regulators at points when data were not mature required significant efforts in communication with the regulators by the DMC to avoid inappropriate early trial termination

Efficacy and safety of dapagliflozin in heart failure with reduced ejection fraction according to age: insights from DAPA-HF

Background: The DAPA-HF trial (Dapagliflozin and Prevention of Adverse-Outcomes in Heart Failure) showed that dapagliflozin added to other guideline-recommended therapies reduced the risk of mortality and heart failure hospitalization and improved symptoms in patients with heart failure and reduced ejection fraction. We examined the effects of dapagliflozin according to age, given potential concerns about the efficacy and safety of therapies in the elderly. Methods: Patients in New York Heart Association functional class II or greater with a left ventricular ejection fraction ≤40% and a modest elevation of NT-proBNP (N-terminal pro-B-type natriuretic peptide) were eligible. Key exclusion criteria included systolic blood pressure <95 mm Hg and estimated glomerular filtration rate <30 mL·min−1·1.73 m−2. The primary outcome was the composite of an episode of worsening heart failure (heart failure hospitalization or urgent heart failure visit) or cardiovascular death, whichever occurred first. Results: A total of 4744 patients 22 to 94 years of age (mean age, 66.3 [SD 10.9] years) were randomized: 636 patients (13.4%) were <55 years of age, 1242 (26.2%) were 55 to 64 years of age, 1717 (36.2%) were 65 to 74 years of age, and 1149 (24.2%) were ≥75 years of age. The rate of the primary outcome (per 100 person-years, placebo arm) in each age group was 13.6 (95% CI, 10.4–17.9), 15.7 (95% CI, 13.2–18.7), 15.1 (95% CI, 13.1–17.5), and 18.0 (95% CI, 15.2–21.4) with corresponding dapagliflozin/placebo hazard ratios of 0.87 (95% CI, 0.60–1.28), 0.71 (95% CI, 0.55–0.93), 0.76 (95% CI, 0.61–0.95), and 0.68 (95% CI, 0.53–0.88; P for interaction=0.76). Consistent benefits were observed for the components of the primary outcome, all-cause mortality, and symptoms. Although adverse events and study drug discontinuation increased with age, neither was significantly more common with dapagliflozin in any age group. Conclusions: Dapagliflozin reduced the risk of death and worsening heart failure and improved symptoms across the broad spectrum of age studied in DAPA-HF. There was no significant imbalance in tolerability or safety events between dapagliflozin and placebo, even in elderly individuals

Dapagliflozin and new-onset type 2 diabetes in patients with chronic kidney disease or heart failure:pooled analysis of the DAPA-CKD and DAPA-HF trials

Background: Chronic kidney disease and heart failure are insulin resistant states associated with a high incidence of diabetes. We assessed the effect of dapagliflozin on new-onset type 2 diabetes in a pooled analysis of patient-level data from the DAPA-CKD and DAPA-HF trials. Methods: This study is a pooled analysis of individual participant data from two phase 3, randomised, double-blind, placebo-controlled, multicentre, clinical trials. Participants with no history of diabetes and HbA1c less than 6·5% (48 mmol/mol) at baseline were included in this pooled analysis. New-onset type 2 diabetes was a prespecified exploratory endpoint in both DAPA-CKD and DAPA-HF trials and is the focus of this analysis. New-onset type 2 diabetes was identified by serial trial measurements of HbA1c (two consecutive values ≥6·5% [≥48 mmol/mol]) or following a clinical diagnosis of diabetes between trial visits. Time to new-onset type 2 diabetes was analysed in a Cox proportional Hazards model from random assignment to end of treatment. Findings: 4003 participants (1398 [34·9%] from the DADA-CKD trial and 2605 [65·1%] from the DAPA-HF trial) were included in our analysis: 1995 (49·8%) had received dapagliflozin and 2008 (50·2%) had received placebo. Over a median follow-up of 21·2 months (IQR 16·0 to 25·4), 126 (6·3%) of 2008 patients in the placebo group (event rate 3·9 per 100 patient-years) and 85 (4·3%) of 1995 patients in the dapagliflozin group (event rate 2·6 per 100 patient-years) developed type 2 diabetes (hazard ratio 0·67 [95% CI 0·51 to 0·88]; p=0·0040). There was no heterogeneity between studies (p interaction 0·77) and there was no clear evidence that the effect of dapagliflozin varied in prespecified subgroups including sex, age, glycaemic status, BMI, glomerular filtration rate, systolic blood pressure, and baseline cardiovascular medication use. More than 90% of the participants who developed type 2 diabetes had prediabetes at baseline (HbA1c 5·7% to 6·4% [39 to 46 mmol/mol]). Mean HbA1c remained unchanged (placebo-adjusted change in the dapagliflozin group of −0·01% [95% CI −0·03 to 0·01], −0·1 mmol/mol [95% CI −0·3 to 0·1] at 12 months). Interpretation: Treatment with dapagliflozin reduced the incidence of new-onset type 2 diabetes in participants with chronic kidney disease and HF without a reduction in HbA1c. Funding: AstraZeneca

Effects of dapagliflozin on symptoms, function and quality of life in patients with heart failure and reduced ejection fraction: results from the DAPA-HF trial

Background: Goals of management in patients with heart failure and reduced ejection fraction include reducing death and hospitalizations, and improving health status (symptoms, physical function, and quality of life). In the DAPA-HF trial (Dapagliflozin and Prevention of Adverse-Outcomes in Heart Failure), sodium–glucose cotransporter-2 inhibitor, dapagliflozin, reduced death and hospitalizations, and improved symptoms in patients with heart failure and reduced ejection fraction. In this analysis, we examine the effects of dapagliflozin on a broad range of health status outcomes, using the Kansas City Cardiomyopathy Questionnaire (KCCQ). Methods: KCCQ was evaluated at randomization, 4 and 8 months. Patients were divided by baseline KCCQ total symptom score (TSS); Cox proportional hazards models examined the effects of dapagliflozin on clinical events across these subgroups. We also evaluated the effects of dapagliflozin on KCCQ-TSS, clinical summary score, and overall summary score. Responder analyses were performed to compare proportions of dapagliflozin versus placebo-treated patients with clinically meaningful changes in KCCQ at 8 months. Results: A total of 4443 patients had available KCCQ at baseline (median KCCQ-TSS, 77.1 [interquartile range, 58.3–91.7]). The effects of dapagliflozin vs placebo on reducing cardiovascular death or worsening heart failure were consistent across the range of KCCQ-TSS (lowest to highest tertile: hazard ratio, 0.70 [95% CI, 0.57–0.86]; hazard ratio, 0.77 [95% CI, 0.61–0.98]; hazard ratio, 0.62 [95% CI, 0.46–0.83]; P for heterogeneity=0.52). Patients treated with dapagliflozin had greater improvement in mean KCCQ-TSS, clinical summary score, and overall summary score at 8 months (2.8, 2.5 and 2.3 points higher versus placebo; P<0.0001 for all). Fewer patients treated with dapagliflozin had a deterioration in KCCQ-TSS (odds ratio, 0.84 [95% CI, 0.78–0.90]; P<0.0001); and more patients had at least small, moderate, and large improvements (odds ratio, 1.15 [95% CI, 1.08–1.23]; odds ratio, 1.15 [95% CI, 1.08–1.22]; odds ratio, 1.14 [95% CI, 1.07–1.22]; number needed to treat=14, 15, and 18, respectively; P<0.0001 for all; results consistent for KCCQ clinical summary score and overall summary score). Conclusions: Dapagliflozin reduced cardiovascular death and worsening heart failure across the range of baseline KCCQ, and improved symptoms, physical function, and quality of life in patients with heart failure and reduced ejection fraction. Furthermore, dapagliflozin increased the proportion of patients experiencing at least small, moderate, and large improvements in health status; these effects were clinically important

Efficacy and safety of sodium–glucose co‐transporter 2 inhibition according to left ventricular ejection fraction in DAPA‐HF

AIMS:The aim of this study was to examine whether left ventricular ejection fraction (LVEF) modified efficacy and safety of dapagliflozin 10 mg compared with placebo in the 4744 patients with LVEF ≤40% randomized in the Dapagliflozin And Prevention of Adverse-outcomes in Heart Failure trial (DAPA-HF). METHODS AND RESULTS:We examined whether LVEF, analysed categorically or continuously, modified the effect of dapagliflozin. The primary efficacy outcome was the composite of a worsening heart failure (HF) event (unplanned HF hospitalization/an urgent HF visit requiring intravenous therapy) or cardiovascular death. Mean LVEF was 31.1% and LVEF categories analysed were: <26% (n = 1143), 26-30% (n = 1018), 31-35% (n = 1187), and >35% (n = 1396). Each 5% decrease in LVEF was associated with a higher risk of the primary outcome [hazard ratio (HR) 1.18; 95% confidence interval (CI) 1.13-1.24]. The benefit of dapagliflozin was consistent across the spectrum of LVEF: the dapagliflozin vs. placebo HR was 0.75 (95% CI 0.59-0.95) for LVEF <26%, 0.75 (0.57-0.98) for LVEF 26-30%, 0.67 (0.51-0.89) for LVEF 31-35%, and 0.83 (0.63-1.09) for LVEF >35% (P for interaction = 0.762). Similarly, the effect of dapagliflozin on the components of the primary endpoint was not modified by baseline LVEF (P for interaction for cardiovascular death = 0.974, and for worsening HF = 0.161). Safety of dapagliflozin was also consistent across the range of LVEF and neither efficacy nor safety were modified by diabetes status. CONCLUSION:Left ventricular ejection fraction was a significant predictor of hospitalization and mortality in patients with HF with reduced ejection fraction but did not modify the beneficial effect of dapagliflozin, overall or separately, in patients with and without diabetes. CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov Identifier NCT03036124

Seismic evidence for large-scale compositional heterogeneity of oceanic core complexes

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q08002, doi:10.1029/2008GC002009.Long-lived detachment faults at mid-ocean ridges exhume deep-seated rocks to form oceanic core complexes (OCCs). Using large-offset (6 km) multichannel seismic data, we have derived two-dimensional seismic tomography models for three of the best developed OCCs on the Mid-Atlantic Ridge. Our results show that large lateral variations in P wave velocity occur within the upper ~0.5–1.7 km of the lithosphere. We observe good correlations between velocity structure and lithology as documented by in situ geological samples and seafloor morphology, and we use these correlations to show that gabbros are heterogeneously distributed as large (tens to >100 km2) bodies within serpentinized peridotites. Neither the gabbros nor the serpentinites show any systematic distribution with respect to along-isochron position within the enclosing spreading segment, indicating that melt extraction from the mantle is not necessarily focused at segment centers, as has been commonly inferred. In the spreading direction, gabbros are consistently present toward the terminations of the detachment faults. This suggests enhanced magmatism during the late stage of OCC formation due either to natural variability in the magmatic cycle or to decompression melting during footwall exhumation. Heat introduced into the rift valley by flow and crystallization of this melt could weaken the axial lithosphere and result in formation of new faults, and it therefore may explain eventual abandonment of detachments that form OCCs. Detailed seismic studies of the kind described here, when constrained by seafloor morphology and geological samples, can distinguish between major lithological units such as volcanics, gabbros, and serpentinized peridotites at lateral scales of a few kilometers. Thus such studies have tremendous potential to elucidate the internal structure of the shallow lithosphere and to help us understand the tectonic and magmatic processes by which they were emplaced.This research was supported by grants from the U.S. NSF-IODP Program