Capture of nebular gases during Earth's accretion is preserved in deep-mantle neon.

Evidence for the capture of nebular gases by planetary interiors would place important constraints on models of planet formation. These constraints include accretion timescales, thermal evolution, volatile compositions and planetary redox states1-7. Retention of nebular gases by planetary interiors also constrains the dynamics of outgassing and volatile loss associated with the assembly and ensuing evolution of terrestrial planets. But evidence for such gases in Earth's interior remains controversial8-14. The ratio of the two primordial neon isotopes, 20Ne/22Ne, is significantly different for the three potential sources of Earth's volatiles: nebular gas15, solar-wind-irradiated material16 and CI chondrites17. Therefore, the 20Ne/22Ne ratio is a powerful tool for assessing the source of volatiles in Earth's interior. Here we present neon isotope measurements from deep mantle plumes that reveal 20Ne/22Ne ratios of up to 13.03 ± 0.04 (2 standard deviations). These ratios are demonstrably higher than those for solar-wind-irradiated material and CI chondrites, requiring the presence of nebular neon in the deep mantle. Furthermore, we determine a 20Ne/22Ne ratio for the primordial plume mantle of 13.23 ± 0.22 (2 standard deviations), which is indistinguishable from the nebular ratio, providing robust evidence for a reservoir of nebular gas preserved in the deep mantle today. The acquisition of nebular gases requires planetary embryos to grow to sufficiently large mass before the dissipation of the protoplanetary disk. Our observations also indicate distinct 20Ne/22Ne ratios between deep mantle plumes and mid-ocean-ridge basalts, which is best explained by addition of a chondritic component to the shallower mantle during the main phase of Earth's accretion and by subsequent recycling of seawater-derived neon in plate tectonic processes.

Chondrules reveal large-scale outward transport of inner Solar System materials in the protoplanetary disk.

Dynamic models of the protoplanetary disk indicate there should be large-scale material transport in and out of the inner Solar System, but direct evidence for such transport is scarce. Here we show that the ε50Ti-ε54Cr-Δ17O systematics of large individual chondrules, which typically formed 2 to 3 My after the formation of the first solids in the Solar System, indicate certain meteorites (CV and CK chondrites) that formed in the outer Solar System accreted an assortment of both inner and outer Solar System materials, as well as material previously unidentified through the analysis of bulk meteorites. Mixing with primordial refractory components reveals a "missing reservoir" that bridges the gap between inner and outer Solar System materials. We also observe chondrules with positive ε50Ti and ε54Cr plot with a constant offset below the primitive chondrule mineral line (PCM), indicating that they are on the slope ∼1.0 in the oxygen three-isotope diagram. In contrast, chondrules with negative ε50Ti and ε54Cr increasingly deviate above from PCM line with increasing δ18O, suggesting that they are on a mixing trend with an ordinary chondrite-like isotope reservoir. Furthermore, the Δ17O-Mg# systematics of these chondrules indicate they formed in environments characterized by distinct abundances of dust and H2O ice. We posit that large-scale outward transport of nominally inner Solar System materials most likely occurred along the midplane associated with a viscously evolving disk and that CV and CK chondrules formed in local regions of enhanced gas pressure and dust density created by the formation of Jupiter.

Temporal Trends in Reperfusion Delivery and Clinical Outcomes Following Implementation of a Regional STEMI Protocol: A 12-Year Perspective.

Background: The Vancouver Coastal Health (VCH) ST-elevation myocardial infarction (STEMI) program aimed to increase access to primary percutaneous coronary intervention (PPCI) and reduce first-medical-contact-to-device times (FMC-DTs). We evaluated the long-term program impact on PPCI access and FMC-DT, and overall and reperfusion-specific in-hospital mortality. Methods: We analyzed all VCH STEMI patients between June 2007 and November 2019. The primary outcome was the proportion of patients receiving PPCI over 4 program implementation phases over 12 years. We also evaluated overall changes in median FMC-DT and the proportion of patients achieving guideline-mandated FMC-DT, in addition to overall and reperfusion-specific in-hospital mortality. Results: A total of 3138 of 4305 VCH STEMI patients were treated with PPCI. PPCI rates increased from 40.2% to 78.7% from 2007 to 2019 (P < 0.001). From phase 1 to 4, median FMC-DT improved from 118 to 93 minutes (percutaneous coronary intervention [PCI]-capable hospitals, P < 0.001) and from 174 to 118 minutes (non-PCI-capable hospitals, P < 0.001), with a concomitant increase in those achieving guideline-mandated FMC-DT (35.5% to 66.1%, P < 0.001). Overall in-hospital mortality was 9.0% (P = 0.20 across phases), with mortality differing significantly by reperfusion strategy (4.0% fibrinolysis, 5.7% PPCI, 30.6% no reperfusion therapy, P < 0.001). Mortality significantly decreased from phase 1 to phase 4 at non-PCI-capable centres (9.6% to 3.9%, P = 0.022) but not at PCI-capable centres (8.7% vs 9.9%, P = 0.27). Conclusions: A regional STEMI program increased the proportion of patients who received PPCI and improved reperfusion times over 12 years. Although no statistically significant decrease occurred in overall regional mortality incidence, mortality incidence was decreased for patients presenting to non-PCI-capable centres.

Contexte: Le programme sur l'infarctus du myocarde avec élévation du segment ST (STEMI) de la régie régionale de santé Vancouver Coastal Health (VCH) visait à améliorer l'accès à des interventions coronariennes percutanées primaires (ICPP) et à réduire le temps entre le premier contact médical et l'intervention. Nous avons évalué les effets à long terme du programme sur l'accès aux ICPP, sur le temps entre le premier contact médical et l'intervention, ainsi que sur le taux global de mortalité hospitalière et le taux de mortalité hospitalière lié à la reperfusion. Méthodologie: Nous avons analysé les cas de tous les patients admis au programme STEMI de la VCH entre juin 2007 et novembre 2019. Le critère d'évaluation principal était la proportion de patients recevant une ICPP pendant les 4 phases du programme, qui se sont étalées sur 12 ans. Nous avons aussi évalué la variation totale du temps médian entre le premier contact médical et l'intervention, et de la proportion de patients chez qui le temps recommandé entre le premier contact médical et l'intervention a été respecté ainsi que la variation du taux global de mortalité hospitalière et du taux de mortalité hospitalière lié à la reperfusion. Résultats: Au total, 3138 des 4305 patients du programme STEMI de la VCH ont été traités par une ICPP. Les taux d'ICPP sont passés de 40,2 % à 78,7 % entre 2007 et 2019 (p < 0,001). De la phase 1 à la phase 4 du programme, le temps médian entre le premier contact médical et l'intervention s'est amélioré, passant de 118 minutes à 93 minutes (hôpitaux en mesure d'effectuer une intervention coronarienne percutanée [ICP]; p < 0,001) et de 174 à 118 minutes (hôpitaux n'étant pas en mesure d'effectuer une ICP; p < 0,001), avec une augmentation du nombre de personnes pour qui le temps recommandé entre le premier contact médical et l'intervention a été respecté (35,5 % à 66,1 %; p < 0,001). Le taux global de mortalité hospitalière était de 9,0 % (p = 0,20 pour toutes les phases), et le taux de mortalité hospitalière lié à la reperfusion différait de manière significative selon la stratégie adoptée (fibrinolyse : 4,0 %; ICPP : 5,7 %; aucune reperfusion : 30,6 %; p < 0,001). Le taux de mortalité a diminué de manière significative entre la phase 1 et la phase 4 dans les centres qui n'étaient pas en mesure d'effectuer une ICP (9,6 % à 3,9 %; p = 0,022), mais pas dans les centres en mesure d'effectuer une ICP (8,7 % c. 9,9 %; p = 0,27). Conclusions: Le programme STEMI régional a permis d'augmenter la proportion de patients qui ont reçu une ICPP et d'améliorer les temps de reperfusion sur 12 ans. Bien qu'aucune diminution statistiquement significative n'ait été observée quant au taux global de mortalité dans la région, le taux de mortalité a diminué chez les patients se présentant dans un centre qui n'était pas en mesure d'effectuer une ICP.

Effects of renin-angiotensin-aldosterone-system inhibitors on coronary atherosclerotic plaques: The PARADIGM registry.

BACKGROUND AND AIMS: Inhibition of Renin-Angiotensin-Aldosterone-System (RAAS) has been hypothesized to improve endothelial function and reduce plaque inflammation, however, their impact on the progression of coronary atherosclerosis is unclear. We aim to study the effects of RAAS inhibitor on plaque progression and composition assessed by serial coronary CT angiography (CCTA). METHODS: We performed a prospective, multinational study consisting of a registry of patients without history of CAD, who underwent serial CCTAs. Patients using RAAS inhibitors were propensity matched to RAAS inhibitor naïve patients based on clinical and CCTA characteristics at baseline. Atherosclerotic plaques in CCTAs were quantitatively analyzed for percent atheroma volume (PAV) according to plaque composition. Interactions between RAAS inhibitor use and baseline PAV on plaque progression were assessed in the unmatched cohort using a multivariate linear regression model. RESULTS: Of 1248 patients from the registry, 299 RAAS inhibitor taking patients were matched to 299 RAAS inhibitor naïve patients. Over a mean interval of 3.9 years, there was no significant difference in annual progression of total PAV between RAAS inhibitor naïve vs taking patients (0.75 vs 0.79%/year, p = 0.66). With interaction testing in the unmatched cohort, however, RAAS inhibitor use was significantly associated with lower non-calcified plaque progression (Beta coefficient -0.100, adjusted p = 0.038) with higher levels of baseline PAV. CONCLUSIONS: The use of RAAS inhibitors over a period of nearly 4 years did not significantly impact on total atherosclerotic plaque progression or various plaque components. However, interaction testing to assess the differential effect of RAAS inhibition based on baseline PAV suggested a significant decrease in progression of non-calcified plaque in patients with a higher burden of baseline atherosclerosis, which should be considered hypothesis generating.

Acute Myocarditis Following mRNA-1273 SARS-CoV-2 Vaccination.

Myocarditis has been described previously as a rare side effect of both influenza and smallpox vaccines. In this report, we present a case of acute perimyocarditis in a young, healthy man after vaccination with the mRNA-1273 severe acute respiratory syndrome coronavirus -2 (SARS-CoV-2; Moderna) vaccine. He presented with chest pain and decompensated heart failure 3 days after administration of his second dose, and his symptoms resolved by 9 days post-inoculation. This case highlights a rare but potentially serious side effect of this mRNA vaccine that primary care physicians and cardiologists should be aware of in order to identify and appropriately manage these patients.

La myocardite a auparavant été considérée comme un effet secondaire rare des vaccins antigrippaux et antivarioliques. Dans ce rapport, nous présentons le cas d'un homme, jeune et en bonne santé, atteint d'une périmyocardite aiguë après avoir reçu le vaccin à ARNm-1273 contre le coronavirus du syndrome respiratoire aigu sévère 2 (SARS-CoV-2, de l'anglais severe acute respiratory syndrome coronavirus-2; Moderna). Il a éprouvé une douleur thoracique et présenté une décompensation cardiaque 3 jours après l'administration de la seconde dose. Les symptômes se sont résorbés 9 jours après l'inoculation. Ce cas illustre un effet secondaire rare, mais potentiellement sérieux, de ce vaccin à ARNm, que les médecins de premier recours et les cardiologues doivent connaître pour être en mesure de détecter et prendre en charge adéquatement ces patients.

Establishing reference ranges for ambulatory electrocardiography parameters: meta-analysis.

OBJECTIVE: Despite the widespread and increasing use of ambulatory electrocardiography (ECG), there is no consensus on reference ranges for ambulatory electrocardiogram parameters to guide interpretation. We sought to determine population distribution-based reference ranges for parameters measured during ambulatory electrocardiogram in healthy adults, based on existing literature. METHODS: We searched multiple databases from 1950 to 2020. Articles reporting original data from ≥24-hour ambulatory electrocardiogram monitoring in healthy adults were included. Data extraction and synthesis were performed according to Meta-analysis of Observational Studies in Epidemiology guidelines. The prevalence/mean and SD for common parameters (sinus pauses, conduction abnormalities and ectopy) were extracted by age group (18-39, 40-59, 60-79 and 80+ years). RESULTS: We identified 33 studies involving 6466 patients. Sinus pauses of >3 s were rare (pooled prevalence <1%) across all ages. Supraventricular ectopy of >1000/24 hours increased with age, from 0% (95% CI 0% to 0%) in those aged 18-39 years to 6% (95% CI 0% to 17%) in those aged 60-79 years. Episodes of supraventricular tachycardia increased from 3% (95% CI 1% to 6%) in those aged 18-39 years to 28% (95% CI 9% to 52%) in those aged 60-79 years. Ventricular ectopy of >1000/24 hours also increased with age, from 1% (95% CI 0% to 2%) in those aged 18-39 years to 5% (95% CI 1% to 10%) in those aged 60-79 years. Episodes of non-sustained ventricular tachycardia ranged from 0% (95% CI 0% to 1%) in those aged 18-39 years to 2% (95% CI 0% to 5%) in those aged 60-79 years. CONCLUSION: Despite the limitations of existing published data, this meta-analysis provides evidence-based reference ranges for ambulatory electrocardiogram parameters and highlights significant age-dependent differences that should be taken into account during interpretation.

Titanium isotope signatures of calcium-aluminum-rich inclusions from CV and CK chondrites: Implications for early Solar System reservoirs and mixing.

Calcium-aluminum-rich inclusions (CAIs) are the first solids to form in the early Solar System, and they exhibit nucleosynthetic anomalies in many isotope systems. The overwhelming majority of isotopic data for CAIs has been limited to inclusions from the CV chondrite Allende and a select few other CV, CO, CM, and ordinary chondrites. It is therefore important to ascertain whether previously reported values for CAIs are representative of the broader CAI-forming region and to make a more rigorous assessment of the extent and implications of isotopic heterogeneity in the early Solar System. Here, we report the mass-independent Ti isotopic compositions of a suite of 23 CAIs of diverse petrologic and geochemical types, including 11 from Allende and 12 from seven other CV3 and CK3 chondrites; the data for CAIs from CK chondrites represent the first reported measurements of Ti isotope compositions of refractory inclusions from this meteorite class. The resolved variation in the mass-independent Ti isotopic compositions of these CAIs indicates that the CAI-forming region of the early Solar System preserved isotopic variability at their time of formation. Nevertheless, the range of Ti isotope compositions reported here for CAIs from CV and CK chondrites falls within the range observed in previously analyzed CAIs from CV, CO, CM, and ordinary chondrites. This implies that CAIs from CV, CK, CO, CM, and ordinary chondrites originated from a common nebular source reservoir characterized by mass-independent isotopic variability in Ti (and other select elements). We further interpret these data to indicate that the Ti isotope anomalies in CAIs represent the isotopic signatures of supernova components in presolar grains that were incorporated into the Solar System in an initially poorly mixed reservoir that was progressively homogenized over time. We conclude that the differing degrees of isotopic variability observed for different elements in normal CAIs are the result of distinct carrier phases and that these CAIs were likely formed towards the final stages of homogenization of the large-scale isotopic heterogeneity that initially existed in the solar nebula.

Petrogenesis and Provenance of Ungrouped Achondrite Northwest Africa 7325 from Petrology, Trace Elements, Oxygen, Chromium and Titanium Isotopes, and Mid-IR Spectroscopy.

Northwest Africa (NWA) 7325 is an ungrouped achondrite that has recently been recognized as a sample of ancient differentiated crust from either Mercury or a previously unknown asteroid. In this work we augment data from previous investigations on petrography and mineral compositions, mid-IR spectroscopy, and oxygen isotope compositions of NWA 7325, and add constraints from Cr and Ti isotope compositions on the provenance of its parent body. In addition, we identify and discuss notable similarities between NWA 7325 and clasts of a rare xenolithic lithology found in polymict ureilites. NWA 7325 has a medium grained, protogranular to poikilitic texture, and consists of 10-15 vol. % Mg-rich olivine (Fo 98), 25-30 vol. % diopside (Wo 45, Mg# 98), 55-60 vol. % Ca-rich plagioclase (An 90), and trace Cr-rich sulfide and Fe,Ni metal. We interpret this meteorite to be a cumulate that crystallized at ≥1200 °C and very low oxygen fugacity (similar to the most reduced ureilites) from a refractory, incompatible element-depleted melt. Modeling of trace elements in plagioclase suggests that this melt formed by fractional melting or multi-stage igneous evolution. A subsequent event (likely impact) resulted in plagioclase being substantially remelted, reacting with a small amount of pyroxene, and recrystallizing with a distinctive texture. The bulk oxygen isotope composition of NWA 7325 plots in the range of ureilites on the CCAM line, and also on a mass-dependent fractionation line extended from acapulcoites. The ε54Cr and ε50Ti values of NWA 7325 exhibit deficits relative to terrestrial composition, as do ordinary chondrites and most achondrites. Its ε54Cr value is distinct from that of any analyzed ureilite, but is not resolved from that of acapulcoites (as represented by Acapulco). In terms of all these properties, NWA 7325 is unlike any known achondrite. However, a rare population of clasts found in polymict ureilites ("the magnesian anorthitic lithology") are strikingly similar to NWA 7325 in mineralogy and mineral compositions, oxygen isotope compositions, and internal textures in plagioclase. These clasts are probably xenolithic in polymict ureilites, and could be pieces of NWA 7325-like meteorites. Using constraints from chromium, titanium and oxygen isotopes, we discuss two possible models for the provenance of the NWA 7325 parent body: 1) accretion in the inner solar system from a reservoir similar to that of acapulcoites in Δ17O, ε54Cr and ε50Ti; or 2) early (< 1 Ma after CAI formation) accretion in the outer solar system (beyond the snow line), before 54Cr and 50Ti anomalies were introduced to this region of the solar system. The mid-IR emission spectrum of NWA 7325 obtained in this work matches its modal mineralogy, and so can be compared with spectra of new meteorites or asteroids/planets to help identify similar materials and/or the parent body of NWA 7325.

Episodic entrainment of deep primordial mantle material into ocean island basalts.

Chemical differences between mid-ocean ridge basalts (MORBs) and ocean island basalts (OIBs) provide critical evidence that the Earth's mantle is compositionally heterogeneous. MORBs generally exhibit a relatively low and narrow range of (3)He/(4)He ratios on a global scale, whereas OIBs display larger variability in both time and space. The primordial origin of (3)He in OIBs has motivated hypotheses that high (3)He/(4)He ratios are the product of mantle plumes sampling chemically distinct material, but do not account for lower MORB-like (3)He/(4)He ratios in OIBs, nor their observed spatial and temporal variability. Here we perform thermochemical convection calculations which show the variable (3)He/(4)He signature of OIBs can be reproduced by deep isolated mantle reservoirs of primordial material that are viscously entrained by thermal plumes. Entrainment is highly time-dependent, producing a wide range of (3)He/(4)He ratios similar to that observed in OIBs worldwide and indicate MORB-like (3)He/(4)He ratios in OIBs cannot be used to preclude deep mantle-sourced hotspots.