A decline in hospitalization for cardiovascular events and catheter laboratory activation was reported for the United States and Italy during the initial stage of the Covid-19 pandemic of 2020. We ...report on the deployment of emergency services for cardiovascular events in a defined region in western Germany during the government-imposed lock-down period.
We examined 5799 consecutive patients who were treated by emergency services for cardiovascular events during the Covid-19 pandemic (January 1 to April 30, 2020), and compared those to the corresponding time frame in 2019. Examining the emergency physicians' records provided by nine locations in the area, we found a 20% overall decline in cardiovascular admissions.
The greatest reduction could be seen immediately following the government-imposed social restrictions. This reduction was mainly driven by a reduction in discretionary admissions for dizziness/syncope (-53%), heart failure (-38%), exacerbated COPD (-28%) and unstable angina (-23%), while unavoidable admissions for ST-elevation myocardial infarction (STEMI), cardiopulmonary resuscitation (CPR) and stroke were unchanged. There was a greater decline in emergency admissions for patients ≥60 years. There was also a greater reduction in emergency admissions for those living in urban areas compared to suburban areas.
During the Covid-19 pandemic, a significant decline in hospitalization for cardiovascular events was observed during the government-enforced shutdown in a predefined area in western Germany. This reduction in admissions was mainly driven by "discretionary" cardiovascular events (unstable angina, heart failure, exacerbated COPD and dizziness/syncope), but events in which admission was unavoidable (CPR, STEMI and stroke) did not change.
Abstract Efficient transfer of S and chalcophile metals through the Earth’s crust in arc systems is paramount for the formation of large magmatic-hydrothermal ore deposits. The formation of ...sulfide-volatile compound drops has been recognized as a potential key mechanism for such transfer but their fate during dynamic arc magmatism remains cryptic. Combining elemental mapping and in-situ mineral analyzes we reconstruct the evolution of compound drops in the active Christiana-Santorini-Kolumbo volcanic field. The observed compound drops are micrometric sulfide blebs associated with vesicles trapped within silicate phenocrysts. The compound drops accumulate and coalesce at mafic-felsic melt interfaces where larger sulfide ovoids form. These ovoids are subsequently oxidized to magnetite during sulfide-volatile interaction. Comparison of metal concentrations between the sulfide phases and magnetite allows for determination of element mobility during oxidation. The formation and evolution of compound drops may be an efficient mechanism for transferring S and chalcophile metals into shallow magmatic-hydrothermal arc systems.
This study aimed to assess the anatomical leaflet variation and investigate its impact on the procedural outcome in patients undergoing transcatheter edge-to-edge tricuspid repair.
Tricuspid ...regurgitation (TR) is associated with a poor prognosis.
The study participants were consecutive patients who underwent transcatheter edge-to-edge tricuspid repair with the MitraClip, TriClip, or PASCAL systems from June 2015 to July 2020 at the Bonn Heart Center. The tricuspid leaflet morphologies were imaged using 2-dimensional and 3-dimensional transesophageal echocardiography. The severity of TR was assessed according to the 5-grade scheme. The primary endpoint was residual TR ≥3+ within 30 days.
Of the 145 study participants, 103 (71.1%) participants were categorized as the 3-leaflet configuration, while 42 (28.9%) were categorized as the 4-leaflet configuration. Successful device implantation was achieved in 136 (93.8%) patients, with no statistical difference between the 3-leaflet and 4-leaflet configuration groups. However, compared with patients with a 3-leaflet configuration, patients with 4-leaflet configuration more frequently had residual TR ≥3+ (18.4% vs 38.1%; P = 0.018). In the multivariable model, the 4-leaflet configuration was associated with an increased risk of residual TR ≥3+ (odds ratio: 2.65; 95% CI 1.15-6.10; P = 0.022), independent of baseline TR grade, coaptation gap width, and TR jet location. After 1-year follow-up, compared with patients with residual TR <3+, patients with residual TR ≥3+ had a significantly higher incidence of the composite of all-cause mortality or heart failure hospitalization (27.7% vs 56.1%; P = 0.016).
A 4-leaflet configuration of the tricuspid valve is observed in approximately one-third of patients undergoing transcatheter edge-to-edge tricuspid repair, which is associated with an increased risk of residual TR after the procedure.
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The European Union recently updated the list of raw materials considered as critical for its industry on the basis of their high economic importance and their relative supply risk. This list now ...defines 26 critical raw materials that include among others, rare earth elements (REE), scandium, vanadium and cobalt. Among the different primary resources of these critical metals, lateritic deposits are particularly targeted. Recent investigations have shown that the latter elements can be accumulated during weathering in consequence of residual and secondary enrichment. These environments are also characterized by significant concentrations of transition metals (e.g. Mn, Cr, Ni), which are not defined as critical to date but remain of primary economic importance.
In this study, we investigate the potential enrichment of some critical (REE, Sc, V, Co) and base transition metals (Mn, Cr, Ni) in Ni-lateritic deposits of New Caledonia by combining mineralogical, bulk-rock, and in situ mineralogical and geochemical approaches. In addition, particular attention was paid to the development of a new standard compound, labelled StdGoe 1.1, to ensure accurate and reproducible analyzes of iron oxides by LA-ICP-MS. Based on this new specifically developed standard, the concentrations obtained for most elements present in iron oxides were shown to be significantly lower, by 20 to 50%, compared to concentrations obtained from calibration using the NIST SRM 610 standard. Such discrepancy is attributed to strong matrix contrasts between finely divided iron oxides particules and the silicate glass NIST standard, and highlight that previous concentrations measured by LA-ICP-MS in iron oxides and available to date in the literature must be considered with care.
Based on this new development, our results show that critical and transition metals are concentrated in different horizons of the lateritic profile. Ni mainly concentrates in secondary Ni-bearing phyllosilicates in saproliths, while it is mainly hosted by goethite in limonite levels. Mn and Co both precipitate as Mn-oxides at the interface between saproliths and limonite facies, while they are sorbed into iron oxides (goethite and hematite) after dissolution of Mn-oxides in the upper levels of the profile. The main fraction of Cr and V is hosted by primary chromites, which are weathering-resistant relative to the other minerals. On the other hand, the Cr and V fraction released after pyroxene dissolution is integrated into goethite. Both elements are thus continuously enriched with increasing weathering level. Rare earth elements mainly accumulate in Mn-oxides horizons. Only Ce is concentrated in the uppermost levels of the lateritic profile, likely in the form of cerianite. Sc is mainly hosted by pyroxenes in the bedrock, and shows a progressive enrichment strongly controlled by goethite in the other horizons. Highest concentrations of Sc are observed at the transition between yellow and red laterites, where the highest proportions of goethite are observed. The decrease of Sc concentration in the iron crust horizon, at the top of the laterite profile, is attributed to the progressive dissolution of goethite and subsequent hematite crystallization.
If the very low REE content of New Caledonia laterites reported in this study make them hardly valuable, Sc concentrations are high enough to be potentially exploited as a Ni-Co by-product. Therefore, it could be worth considering Sc as a new potential resource in New Caledonia laterites in the forthcoming decades.
•Goethite is the main mineral phase carrying metals of economic interest.•Part of Sc is released during the goethite-hematite transition.•Sc may represent a new potential by-product resource of Ni-laterites in New Caledonia.
Clinoenstatite-bearing boninites (CE-boninite) from the serpentinite sole of the Cenozoic ophiolite of New Caledonia near Nepoui have been dated by the 40Ar/39Ar method, yielding two plateau ages of ...47.4±0.9Ma and 50.4±1.3Ma. Coarser grained, geochemically similar boninite-series felsic dikes consistently yielded U–Pb zircon ages of ca. 54Ma.
Nepoui CE-boninites display whole rock geochemical features similar to that of Cape Vogel boninites (Papua-New Guinea). They similarly have been generated by low degree hydrous melting of depleted peridotite. High contents in LILE and LREE, and some elemental ratios suggest source enrichment by subduction-derived fluids and melts. However, unlike the Cape Vogel boninite, moderately depleted MORB-like isotopic signatures (εNd50=7.9) rule out the role of OIB-like, or E-MORB component that might account for the relatively high LREE and LILE contents measured in the rocks. Nd isotopic ratios and positive anomalies in Zr and Hf are closely similar to that of the slightly older felsic dikes (55–50Ma) that crosscut the peridotite from the ophiolite in New Caledonia. Most of these magmas have been generated by slab melting during the early stages of intra-oceanic subduction. The Early Eocene subduction started at or near the “oceanic” ridge and involved young and hot lithosphere; therefore, slab-derived melts may have reacted locally with hot depleted peridotites. Finally, water influx into the mantle wedge during the subduction of slightly older (cooler and hydrated) lithosphere initiated a low degree partial melting event in the mantle wedge and generated the CE-boninite magma.
Geochemical modeling of hydrous melting of a depleted mantle re-enriched by slab melts suggest that the additional slab melt component was derived from the partial melting of a BABB-like barroisite-bearing eclogite, similar to some elements of the Eocene HP–LT Pouebo terrane. This potential magma source is similar to the BABB-like HT amphibolites of the metamorphic sole of the ophiolite, which have the same origin. Geochemical modeling also suggests that CE-boninite magma may have been in equilibrium with the enstatite-bearing gabbro cumulates that crop out in several places of the Massif du Sud.
However, modeling fails in establishing that harzburgite of the same massif simply corresponds to the melting residue of this process. It appears that ultra-depleted supra-subduction peridotites of the Massif du Sud are probably not directly related to the overlying gabbro cumulates.
•CE-boninite and boninite-series felsic dikes of New Caledonia yield Early Eocene 40Ar/39Ar and U–Pb zircon ages respectively•Geochemical modeling suggest source enrichment by subduction-derived fluids and MORB-like melt component•CE-boninite magma may have been in equilibrium with enstatite-bearing gabbro cumulates of the Peridotite Nappe
Serpentinization processes occur at geological settings notably during oceanic subduction and obduction, where mantle rocks interact with water. Different types of serpentine minerals form according ...to temperature and pressure conditions, and potentially chemical exchanges. Therefore, the characterization of serpentine minerals, and the possible occurrence of multiple serpentine generations in mantle rocks provide essential constraints on the conditions of fluid–rock interactions in the mantle. The serpentinite sole of the Peridotite Nappe of New Caledonia (Southwest Pacific) is the result of several superimposed serpentinisation events. The latter were discriminated using mineralogical and geochemical approaches and modeling. Lizardite represents more than 80% of the entire serpentine content of the ophiolite. It is crosscut by several veins of other serpentine species in the serpentinite sole. The relative chronology appears as follows: lizardite 1 → lizardite 2 → antigorite → chrysotile → polygonal serpentine. The transition from primary/magmatic minerals to lizardite 1 is almost isochemical. Then, the development of lizardite 2 yields an enrichment in fluid-mobile elements such as Cs, Rb, Ba, U and light rare-earth elements and an apparent increase of the Fe
3+
/Fe
T
ratio. The modeling of δ
18
O values (1.9–13.9‰) and δD values (88–106‰) of all serpentine species through Monte-Carlo simulations show that New Caledonia serpentines were mainly formed in equilibrium with fluids released by the dehydration of altered oceanic crust (AOC) during subduction between 250 and 350 °C. AOC-derived fluids are not the unique source of fluids since a low temperature (100–150 °C) meteoric component is also predicted by the models. Thus, serpentine acts as a tape-recorder of fluid–rock interactions into the mantle from depth to (sub-)surface.
The source of massive magma production at volcanic rifted margins remains strongly disputed since the first observations of thick lava piles in the 1980s. However, volumes of extruded and intruded ...melt products within rifted continental crust are still not accurately resolved using geophysical methods. Here we investigate the magma budget alongside the South Atlantic margins, at the onset of seafloor spreading, using high-quality seismic reflection profiles to accurately estimate the oceanic crustal thickness. We show that, along ~ 75% of the length of the Early-Cretaceous initial spreading centre, the crustal thickness is similar to regular oceanic thickness with an age > 100 Ma away from hot spots. Thus, most of the southernmost Atlantic Ocean opened without anomalously hot mantle, high magma supply being restricted to the Walvis Ridge area. We suggest that alternative explanations other than a hotter mantle should be favoured to explain the thick magmatic layer of seaward dipping reflectors landward of the initial mid-oceanic ridge.
This paper proposes a detailed study of the formation of the main Ni ore that is today mined in the saprock horizon of New Caledonia ophiolite. More specifically, this study aims at, i) ...characterizing the nature and the crystal chemistry of the main Ni-bearing phases, and ii) better understanding the weathering processes that lead to such nickel enrichment in these horizons. The study focuses on a boulder (~20 cm in diameter) sampled in the saprock facies of the Koniambo massif, reflecting the early stages of peridotite bedrock weathering. This boulder is explored with a large panel of techniques, from the centimeter to the nanometer scale, including micro-imaging and X-ray absorption spectroscopy at the Ni and Fe K-edges. A characterization along the cross section reveals important heterogeneities in textures, and a large concentration of nickel in the outer part through an intense and connected Ni-phyllosilicate network that develop at the expense of the primary lizardite network. The inner part is preserved from the weathering by supergene fluids. Primary lizardite initially contains about 0.4 wt% NiO, similarly to surrounding olivine and pyroxene. In the outer part, the main Ni-bearing phases are identified as polygonal serpentine (up to ~5 wt% NiO) and two successive generations of talc-like minerals that contain ~20 to 36 wt% NiO. In these two minerals, nickel is very likely to form nano-clusters in the octahedral layers. The Fe3+/Fetotal ratios in serpentine minerals increases regularly from ~0.5 in primary lizardite, to ~0.95 in polygonal serpentine, traducing increasing local oxygen fugacity with increasing weathering degree.
From molecular modeling, we propose that the large excess of water systematically observed for these Ni-rich minerals can be explained by nanometer sized crystals, which potentially require many additional hydrogen bonds (i.e., mainly silanol groups) to passivate crystal edges and preserve electro-neutrality. On the other hand, the main driving force leading to important nickel accumulation in the saprock horizon is likely to be the strong pH gradient present at all scales in the regolith profile, including at the boulder scale, which have major effects on the hydroxide solubility. As the pH decreases in the phyllosilicate network, we observe, i) the weathering and oxidation of the primary lizardite network, ii) the formation of a newly formed lizardite, iii) the formation of Ni-rich polygonal serpentine, iv) the formation of successive generations of Ni-rich talc-like minerals.
•Ni-bearing minerals in saprock are of serpentine type and mainly talc-like type.•Nickel is nano-clustered in Ni-rich talc-like minerals.•Ni-rich talc-like minerals are nano-crystals with high silanol groups at the edges.•Ni enrichment is controlled by pH gradients that affect hydroxide solubility.•Ni enrichment process involves pre-existing phyllosilicate veins.
OBJECTIVESThe aim of this study was to develop a machine learning (ML)-based risk stratification tool for 1-year mortality in transcatheter mitral valve repair (TMVR) patients incorporating metabolic ...and hemodynamic parameters. BACKGROUNDThe lack of appropriate, well-validated, and specific means to risk-stratify patients with mitral regurgitation complicates the evaluation of prognostic benefits of TMVR in clinical trials and practice. METHODSA total of 1,009 TMVR patients from 3 university hospitals within the Heart Failure Network Rhineland were included; 1 hospital (n = 317) served as external validation. The primary endpoint was all-cause 1-year mortality. Model performance was assessed using receiver-operating characteristic curve analysis. In the derivation cohort, different ML algorithms were tested using 5-fold cross-validation. The final model, called MITRALITY (transcatheter mitral valve repair mortality prediction system) was tested in the validation cohort with respect to existing clinical scores. RESULTSExtreme gradient boosting was selected for the MITRALITY score, using only 6 baseline clinical features for prediction (in order of predictive importance): urea, hemoglobin, N-terminal pro-brain natriuretic peptide, mean arterial pressure, body mass index, and creatinine. In the external validation cohort, the MITRALITY score's area under the curve was 0.783 (95% CI: 0.716-0.849), while existing scores yielded areas under the curve of 0.721 (95% CI: 0.63-0.811) and 0.657 (95% CI: 0.536-0.778) at best. CONCLUSIONSThe MITRALITY score is a novel, internally and externally validated ML-based tool for risk stratification of patients prior to TMVR, potentially serving future clinical trials and daily clinical practice.
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