The emergence of severe acute respiratory syndrome coronavirus 2 virus, which causes coronavirus disease 2019 (COVID-19), led to the declaration of a global pandemic by the World Health Organization ...on March 11, 2020. As of February 6, 2021, over 105 million persons have been infected in 223 countries and there have been 2,290,488 deaths. As a result, emergency medical services and hospital systems have undergone unprecedented healthcare delivery reconfigurations. Here, we review the effects of the COVID-19 pandemic on out-of-hospital cardiac arrest (OHCA) epidemiology and systems of care.
Areas severely affected by the pandemic have reported increased incidence of OHCA, lower rates of successful resuscitation, and increased mortality. COVID-19 has significantly impacted patient outcomes through increased disease severity, decreased access to care, and the reshaping of emergency medical response and hospital-based healthcare systems and policies. The pandemic has negatively influenced attitudes toward resuscitation and challenged providers with novel ethical dilemmas provoked by the scarcity of healthcare resources.
The COVID-19 pandemic has had direct, indirect, psychosocial, and ethical impacts on the cardiac arrest chain of survival.
The possibility of identifying the sources of terrigenous rocks based on geochemical data using a linear programming model is considered by the example of metasedimentary rocks of the Sakukan ...Formation of the Kemen Group of the Udokan Complex, Aldan Shield. It is shown that tonalite–trondhjemite gneisses (56.9%) and leucocratic granite–gneisses (17.3%) of the Olekma complex, Paleoproterozoic granitoids of the Kuanda Complex (7.6%) of the Chara-Olekma geoblock, metavolcanic rocks of the Fedorov Group (15.4%) and gneiss–granites (1.8%) of the West Aldan megablock developed within it could be the sources of metasandstones of the Sakukan Formation. The results obtained are in good agreement with the Nd isotopic and geochronological data available for the metasandstones of the Sakukan Formation, which indicates the wide possibilities of identifying and searching for sources of terrigenous deposits using a linear programming model.
The results of U–Th–Pb (LA-ICP-MS) geochronological studies of detrital zircon from metasandstones of the Kodar Group of the Udokan Complex of the Aldan Shield are presented. It has been established ...that the Kodar Group of the Udokan subzone of the Kodar–Udokan trough has an age of 2.08–2.05 Ga. The provenance areas of the Kodar Group deposits were the Archean (ca. 2.65, 2.83, and 3.23 Ga) igneous and metamorphic complexes of the Chara–Olekma Geoblock of the Aldan Shield and the adjacent territory of the Stanovoi suture zone, as well as Paleoproterozoic (ca. 2.08 Ga) island arcs or active continental margin complexes that existed in the southern margin of the Archean Chara–Olekma Geoblock and are unidentified on the present erosional level. It is assumed that rocks of different ages, belonging both to the Kodar Group of the Udokan Complex and to the metamorphic complexes of the Stanovoi suture zone, can be tectonically juxtaposed in the southern part of the Udokan subzone of the Kodar–Udokan trough.
Geochemical, geochronological (U–Pb on zircons, ID TIMS), and isotope–geochemical (Sm–Nd) studies of Kopri-type granitoids of the Tukuringra Complex have been carried out. The granitoids are located ...exclusively in the zone of the Dzheltulak suture, which separates the Dzhugdzhur–Stanovoi and Western Stanovoi superterranes of the Central Asian fold belt. It has been established that they can be classified as postcollisional adakite-like granitoids of elevated alkalinity and adakite-type basicity, formed in the age range between 127 ± 1 and 126 ± 1 Ma, which are part of the Late Mesozoic postcollisional Stanovoi volcano-plutonic belt that extends more than 1000 km in the sublatitudinal direction from the Sea of Okhotsk into the continent subparallel to the Mongolia–Okhotsk suture zone and stitches the Dzhugdzhur–Stanovoi and the Western Stanovoi superterranes. The structural position of the Kopri-type granitoid massifs registers the upper age limit of the Dzheltulak suture. Formation of the parent melts of these granitoids is associated with an essentially lithospheric source formed as a result of mixing of the Early Precambrian and a younger, apparently Phanerozoic component. In contrast to other granitoids of the Stanovoi belt that are close in composition and age, the granitoids under consideration are characterized by a certain increase in the role of the asthenospheric component in their source, which is probably due to their localization in the zone of elevated lithospheric permeability and at the junction of faults of different orientations, generally sublatitudinal, guided by the Mongolia–Okhotsk lineament, and northwestward, associated with the development of the Dzheltulak suture.
Objectives
To describe the outcomes of urgent/emergent transcatheter edge‐to‐edge mitral valve repair (TMVr) and compare the clinical, echocardiographic, and procedural characteristics of survivors ...and nonsurvivors.
Background
TMVr is a treatment strategy for select patients with severe primary or secondary mitral regurgitation. However, knowledge regarding outcomes for urgent/emergent TMVr is limited.
Methods
All urgent or emergent TMVr procedures using MitraClip performed at the University of Washington Medical Center between January 2018 and March 2019 were identified and clinical, echocardiographic, hemodynamic, procedural, and outcomes data were obtained by chart review. Outcomes included all‐cause mortality, hospital mortality, procedural success, periprocedural complications, and hospital readmission.
Results
Of the 20 patients who underwent urgent/emergent TMVr, eight were treated for cardiogenic shock (CS), four for acute decompensated heart failure (ADHF) with hypoxemic respiratory failure requiring mechanical ventilation, and eight for ADHF with failure of inpatient medical therapy. Mechanical circulatory support (MCS) was used in six patients; preceding TMVr in three patients and immediately post‐TMVr in three patients. Overall, 30‐day mortality and hospital readmission rates were 21 and 13%, respectively. Over a median 153 days (IQR 20–491) of follow‐up, 10 patients (50%) died. Preprocedure CS, new or ongoing MCS post‐TMVr, refractory respiratory failure post‐TMVr, and acute kidney injury post‐TMVr were associated with mortality.
Conclusions
In a single‐center retrospective analysis, urgent/emergent TMVr in high‐risk patients with ADHF or CS was associated with high short‐term mortality and periprocedural complications. Prospective studies are warranted to inform patient selection and periprocedural management for urgent/emergent TMVr.
Climate warming is causing rapid loss of glaciers and snowpack in mountainous regions worldwide. These changes are predicted to negatively impact the habitats of many range‐restricted species, ...particularly endemic, mountaintop species dependent on the unique thermal and hydrologic conditions found only in glacier‐fed and snow melt‐driven alpine streams. Although progress has been made, existing understanding of the status, distribution, and ecology of alpine aquatic species, particularly in North America, is lacking, thereby hindering conservation and management programs. Two aquatic insects – the meltwater stonefly (Lednia tumana) and the glacier stonefly (Zapada glacier) – were recently proposed for listing under the U.S. Endangered Species Act due to climate‐change‐induced habitat loss. Using a large dataset (272 streams, 482 total sites) with high‐resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit L. tumana and Z. glacier across the northern Rocky Mountains. Lednia tumana was detected in 113 streams (175 sites) within Glacier National Park (GNP) and surrounding areas. The probability of L. tumana occurrence increased with cold stream temperatures and close proximity to glaciers and permanent snowfields. Similarly, densities of L. tumana declined with increasing distance from stream source. Zapada glacier was only detected in 10 streams (24 sites), six in GNP and four in mountain ranges up to ~600 km southwest. Our results show that both L. tumana and Z. glacier inhabit an extremely narrow distribution, restricted to short sections of cold, alpine streams often below glaciers predicted to disappear over the next two decades. Climate warming‐induced glacier and snow loss clearly imperils the persistence of L. tumana and Z. glacier throughout their ranges, highlighting the role of mountaintop aquatic invertebrates as sentinels of climate change in mid‐latitude regions.
Climate change is causing the loss of glaciers and snowfields worldwide, leading to major changes in alpine stream ecosystems. Using a large dataset with high‐resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit the distributions of two rare alpine insects, the meltwater and western glacier stoneflies, which were recently recommended for listing under the U.S. Endangered Species Act. Our results clearly link the loss of alpine glaciers and snowfields to the fate of both species, providing a rare direct connection between climate‐induced habitat change and mountaintop biodiversity.
This paper reports the results of U–Pb geochronological (ID–TIMS) studies of garnet and U–Th–Pb (LA–ICP–MS) “screening” geochronological studies of zircon from pyroxene–carbonate rocks of the Ukduska ...massif. The U–Pb dates of garnets (1881 ± 8 Ma) and zircon rims (1865 ± 16 Ma) are indicative of the Early Proterozoic age of these rocks. The geochronological results make it possible to identify a new carbonate magmatism stage within the southeastern part of the Chara–Olyokma geoblock.
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The results of U–Th–Pb LA-ICP-MS dating of detrital zircons collected from the Permian–Triassic red beds of the Moscow Basin are presented. U–Th–Pb ages of detrital zircons from two samples (Upper ...Permian and Lower Triassic), which were collected in the vicinity of the P–T boundary in the Zhukov Ravine reference section, show their contrasting provenance. It means that U–Pb detrital zircon geochronology can be used as an additional independent tool for stratigraphic correlation of the Permian–Triassic red beds, at least within the Moscow Basin. The applicability of the method is illustrated by additional constraints on the age of the Nedubrovo member deposits (Vologda Region) with a previously uncertain stratigraphic position: the U–Pb age pattern of the respective detrital zircons suggests their Early Triassic age.
Gene-targeted deletion of the potassium channel Kv1.3 (Kv1.3(-∕-)) results in "Super-smeller" mice with a sensory phenotype that includes an increased olfactory ability linked to changes in olfactory ...circuitry, increased abundance of olfactory cilia, and increased expression of odorant receptors and the G-protein, Golf. Kv1.3(-∕-) mice also have a metabolic phenotype including lower body weight and decreased adiposity, increased total energy expenditure (TEE), increased locomotor activity, and resistance to both diet- and genetic-induced obesity. We explored two cellular aspects to elucidate the mechanism by which loss of Kv1.3 channel in the olfactory bulb (OB) may enhance glucose utilization and metabolic rate. First, using in situ hybridization we find that Kv1.3 and the insulin-dependent glucose transporter type 4 (GLUT4) are co-localized to the mitral cell layer of the OB. Disruption of Kv1.3 conduction via construction of a pore mutation (W386F Kv1.3) was sufficient to independently translocate GLUT4 to the plasma membrane in HEK 293 cells. Because olfactory sensory perception and the maintenance of action potential (AP) firing frequency by mitral cells of the OB is highly energy demanding and Kv1.3 is also expressed in mitochondria, we next explored the structure of this organelle in mitral cells. We challenged wildtype (WT) and Kv1.3(-∕-) male mice with a moderately high-fat diet (MHF, 31.8 % kcal fat) for 4 months and then examined OB ultrastructure using transmission electron microscopy. In WT mice, mitochondria were significantly enlarged following diet-induced obesity (DIO) and there were fewer mitochondria, likely due to mitophagy. Interestingly, mitochondria were significantly smaller in Kv1.3(-∕-) mice compared with that of WT mice. Similar to their metabolic resistance to DIO, the Kv1.3(-∕-) mice had unchanged mitochondria in terms of cross sectional area and abundance following a challenge with modified diet. We are very interested to understand how targeted disruption of the Kv1.3 channel in the OB can modify TEE. Our study demonstrates that Kv1.3 regulates mitochondrial structure and alters glucose utilization; two important metabolic changes that could drive whole system changes in metabolism initiated at the OB.
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