Your browser doesn't support javascript.
Montrer: 20 | 50 | 100
Résultats 1 - 2 de 2
Filtre
Ajouter des filtres

Gamme d'année
1.
Earth System Science Data ; 13(8):4191-4206, 2021.
Article Dans Anglais | ProQuest Central | ID: covidwho-1374612

Résumé

In order to fight the spread of the global COVID-19 pandemic, most of the world's countries have taken control measures such as lockdowns during a few weeks to a few months. These lockdowns had significant impacts on economic and personal activities in many countries. Several studies using satellite and surface observations have reported important changes in the spatial and temporal distributions of atmospheric pollutants and greenhouse gases. Global and regional chemistry-transport model studies are being performed in order to analyze the impact of these lockdowns on the distribution of atmospheric compounds. These modeling studies aim at evaluating the impact of the regional lockdowns at the global scale. In order to provide input for the global and regional model simulations, a dataset providing adjustment factors (AFs) that can easily be applied to current global and regional emission inventories has been developed. This dataset provides, for the January–August 2020 period, gridded AFs at a0.1×0.1 latitude–longitude degree resolution on a daily or monthly basis for the transportation (road, air and ship traffic), power generation, industry and residential sectors. The quantification of AFs is based on activity data collected from different databases and previously published studies. A range of AFs are provided at each grid point for model sensitivity studies. The emission AFs developed in this study are applied to the CAMS global inventory (CAMS-GLOB-ANT_v4.2_R1.1), and the changes in emissions of the main pollutants are discussed for different regions of the world and the first 6 months of 2020. Maximum decreases in the total emissions are found in February in eastern China, with an average reduction of 20 %–30 % in NOx, NMVOCs (non-methane volatile organic compounds) and SO2 relative to the reference emissions. In the other regions, the maximum changes occur in April, with average reductions of 20 %–30 % for NOx, NMVOCs and CO in Europe and North America and larger decreases (30 %–50 %) in South America. In India and African regions, NOx and NMVOC emissions are reduced on average by 15 %–30 %. For the other species, the maximum reductions are generally less than 15 %, except in South America, where large decreases in CO and BC (black carbon) are estimated. As discussed in the paper, reductions vary highly across regions and sectors due to the differences in the duration of the lockdowns before partial or complete recovery.The dataset providing a range of AFs (average and average ± standard deviation) is called CONFORM (COvid-19 adjustmeNt Factors fOR eMissions) (https://doi.org/10.25326/88;Doumbia et al., 2020). It is distributed by the Emissions of atmospheric Compounds and Compilation of Ancillary Data (ECCAD) database (https://eccad.aeris-data.fr/, last access: 23 August 2021).

2.
Preprint Dans Anglais | medRxiv | ID: ppmedrxiv-20154260

Résumé

BackgroundThe clinical description of the neurological manifestations in COVID-19 patients is still underway. This study aims to provide an overview of the spectrum, characteristics and outcomes of neurological manifestations associated with SARS-CoV-2 infection. MethodsWe conducted a nationwide, multicentric, retrospective study during the French COVID-19 epidemic in March-April 2020. All COVID-19 patients with de novo neurological manifestations were eligible. ResultsWe included 222 COVID-19 patients with neurological manifestations from 46 centers throughout the country. Median age was 65 years (IQR 53-72), and 136 patients (61.3%) were male. COVID-19 was severe or critical in almost half of the patients (102, 45.2%). The most common neurological diseases were COVID-19 associated encephalopathy (67/222, 30.2%), acute ischemic cerebrovascular syndrome (57/222, 25.7%), encephalitis (21/222, 9.5%), and Guillain-Barre Syndrome (15/222, 6.8%). Neurological manifestations appeared after first COVID-19 symptoms with a median (IQR) delay of 6 (3-8) days in COVID-19 associated encephalopathy, 7 (5-10) days in encephalitis, 12 (7-18) days in acute ischemic cerebrovascular syndrome and 18 (15-28) days in Guillain-Barre Syndrome. Brain imaging was performed in 192 patients (86.5%), including 157 MRI (70.7%). Brain MRI of encephalitis patients showed heterogeneous acute non vascular lesion in 14/21 patients (66.7%) with associated small ischemic lesion or microhemorrhages in 4 patients. Among patients with acute ischemic cerebrovascular syndrome, 13/57 (22.8%) had multi territory ischemic strokes, with large vessel thrombosis in 16/57 (28.1%). Cerebrospinal fluid was analyzed in 97 patients (43.7%), with pleocytosis in 18 patients (18.6%). A SARS-CoV-2 PCR was performed in 75 patients and was positive only in 2 encephalitis patients. Among patients with encephalitis, ten out of 21 (47.6%) fully recovered, 3 of whom received corticosteroids (CS). Less common neurological manifestations included isolated seizure (8/222, 3.6%), critical illness neuropathy (8/222, 3.6%), transient alteration of consciousness (5/222, 2.3%), intracranial hemorrhage (5/222, 2.3%), acute benign lymphocytic meningitis (3/222, 1.4%), cranial neuropathy (3/222, 1.4%), single acute demyelinating lesion (2/222, 0.9%), Tapia syndrome (2/222, 0.9%), cerebral venous thrombosis (1/222, 0.5%), sudden paraparesis (1/222, 0.5%), generalized myoclonus and cerebellar ataxia (1/222, 0.5%), bilateral fibular palsy (1/222, 0.5%) and isolated neurological symptoms (headache, anosmia, dizziness, sensitive or auditive symptoms, hiccups, 15/222, 6.8%). The median (IQR) follow-up of the 222 patients was 24 (17-34) days with a high short-term mortality rate (28/222, 12.6%). ConclusionNeurological manifestations associated with COVID-19 mainly included CAE, AICS, encephalitis and GBS. Clinical spectrum and outcomes were broad and heterogeneous, suggesting different underlying pathogenic processes.

SÉLECTION CITATIONS
Détails de la recherche