42 research outputs found

    Echocardiography findings in COVID-19 patients admitted to intensive care units: a multi-national observational study (the ECHO-COVID study)

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    Purpose: Severely ill patients affected by coronavirus disease 2019 (COVID-19) develop circulatory failure. We aimed to report patterns of left and right ventricular dysfunction in the first echocardiography following admission to intensive care unit (ICU). Methods: Retrospective, descriptive study that collected echocardiographic and clinical information from severely ill COVID-19 patients admitted to 14 ICUs in 8 countries. Patients admitted to ICU who received at least one echocardiography between 1st February 2020 and 30th June 2021 were included. Clinical and echocardiographic data were uploaded using a secured web-based electronic database (REDCap). Results: Six hundred and seventy-seven patients were included and the first echo was performed 2 [1, 4] days after ICU admission. The median age was 65 [56, 73] years, and 71% were male. Left ventricle (LV) and/or right ventricle (RV) systolic dysfunction were found in 234 (34.5%) patients. 149 (22%) patients had LV systolic dysfunction (with or without RV dysfunction) without LV dilatation and no elevation in filling pressure. 152 (22.5%) had RV systolic dysfunction. In 517 patients with information on both paradoxical septal motion and quantitative RV size, 90 (17.4%) had acute cor pulmonale (ACP). ACP was associated with mechanical ventilation (OR > 4), pulmonary embolism (OR > 5) and increased PaCO2. Exploratory analyses showed that patients with ACP and older age were more likely to die in hospital (including ICU). Conclusion: Almost one-third of this cohort of critically ill COVID-19 patients exhibited abnormal LV and/or RV systolic function in their first echocardiography assessment. While LV systolic dysfunction appears similar to septic cardiomyopathy, RV systolic dysfunction was related to pressure overload due to positive pressure ventilation, hypercapnia and pulmonary embolism. ACP and age seemed to be associated with mortality in this cohort

    A gene encoding an abscisic acid biosynthetic enzyme (LsNCED4) collocates with the high temperature germination locus Htg6.1 in lettuce (Lactuca sp.)

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    Thermoinhibition, or failure of seeds to germinate when imbibed at warm temperatures, can be a significant problem in lettuce (Lactuca sativa L.) production. The reliability of stand establishment would be improved by increasing the ability of lettuce seeds to germinate at high temperatures. Genes encoding germination- or dormancy-related proteins were mapped in a recombinant inbred line population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. This revealed several candidate genes that are located in the genomic regions containing quantitative trait loci (QTLs) associated with temperature and light requirements for germination. In particular, LsNCED4, a temperature-regulated gene in the biosynthetic pathway for abscisic acid (ABA), a germination inhibitor, mapped to the center of a previously detected QTL for high temperature germination (Htg6.1) from UC96US23. Three sets of sister BC3S2 near-isogenic lines (NILs) that were homozygous for the UC96US23 allele of LsNCED4 at Htg6.1 were developed by backcrossing to cv. Salinas and marker-assisted selection followed by selfing. The maximum temperature for germination of NIL seed lots with the UC96US23 allele at LsNCED4 was increased by 2–3°C when compared with sister NIL seed lots lacking the introgression. In addition, the expression of LsNCED4 was two- to threefold lower in the former NIL lines as compared to expression in the latter. Together, these data strongly implicate LsNCED4 as the candidate gene responsible for the Htg6.1 phenotype and indicate that decreased ABA biosynthesis at high imbibition temperatures is a major factor responsible for the increased germination thermotolerance of UC96US23 seeds

    The Electrochemical Performance and Applications of Several Popular Lithium-ion Batteries for Electric Vehicles - A Review

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    The Lithium-ion battery is one of the most common batteries used in Electric Vehicles (EVs) due to the specific features of high energy density, power density, long life span and environment friendly. With the development of lithium-ion battery technology, different materials have been adopted in the design of the cathodes and anodes in order to gain a better performance. LiMn2O4LiMn_{2}O_{4} , LiNiMnCoO2LiNiMnCoO_{2} , LiNiCoAlO2LiNiCoAlO_{2} , LiFePO4LiFePO_{4} and Li4Ti5O12Li_{4}Ti_{5}O_{12} are five common lithium-ion batteries adopted in commercial EVs nowadays. The characteristics of these five lithium-ion batteries are reviewed and compared in the aspects of electrochemical performance and their practical applications

    Lithium-ion batteries working at 85°C: Aging phenomena and electrode/electrolyte interfaces studied by XPS

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    International audienceLi(Ni,Mn,Co)O2/graphite lithium-ion batteries designed to work at high temperature were tested upon cycling at 85°C in various voltage ranges. Aging processes in relation with changes in the electrode/electrolyte interfaces at both electrodes were investigated by X-ray Photoelectron Spectroscopy (XPS). Changes were observed in the composition of the solid electrolyte interphase (SEI) at the surface of graphite electrode due to the high cycling temperature: disappearance of carbonates and increase of inorganic compounds coming from degradation of the salt. A slight dissolution process of the PVdF positive electrode binder was evidenced. It was also observed that the formation and thickness of the passivation layer at the positive electrode surface at 85°C depends on the cycling voltage range. © 2012 The Electrochemical Society

    Nitrogen-depleted Chlorella zofingiensis produces astaxanthin, ketolutein and their fatty acid esters: a carotenoid metabolism study

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    Natural carotenoids such as astaxanthin, ß,ß-carotene and lutein are pigments with a high market value. We studied the effects of nitrogen depletion on the carotenoid metabolism of Chlorella zofingiensis (Chlorophyta) and the subsequent treatment with diphenylamine (DPA), an inhibitor of the biosynthesis of secondary ketocarotenoids. Pigments were identified and quantified based on reversed phase ultrahigh performance liquid chromatography photodiode array tandem mass spectrometry (RP-UHPLC-PDA-MSn). Nitrogen depletion (without DPA) resulted in a degradation of chlorophylls and primary carotenoids and an accumulation of astaxanthin, ketolutein, canthaxanthin, adonixanthin and ß,ß-carotene. The DPA treatment decreased the overall production of ß,ß-carotene derivatives (sum of astaxanthin, canthaxanthin, echinenone and adonixanthin); however, the production of ketolutein and degradation of primary carotenoids were not modified. This suggests that the regulatory mechanisms controlling the flux towards ketolutein and primary carotenoids were not affected by the decreased levels of ß,ß-carotene derivatives. In addition, DPA increased production of the individual carotenoids, adonixanthin and echinenone. Insight into the regulation of microalgal carotenoid biosynthesis as demonstrated in this paper is essential when a large-scale carotenoid production process is to be optimised or a recombinant C. ofingiensis strain is to be designed with the intention of excessively producing primary or secondary carotenoids

    Comparison of levels of genetic diversity detected with AFLP and microsatellite markers within and among mixed Q. petraea (MATT.) LIEBL. and Q. robur L. stands

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    The aim of this study was to compare genetic diversity within and among Quercus spp. populations based on two contrasting types of nuclear markers. Seven mixed stands of Quercus petraea and Quercus robur were analysed using six highly polymorphic and codominantly inherited microsatellite markers as well as 155 dominant AFLP markers. Genetic differentiation and genetic diversity within each population were assessed. The intra- and inter-locus variances were calculated, and the results were used to compare the genetic diversity between populations. Both classes of markers revealed similar results: the genetic diversity within population and the genetic differentiation among populations is greater in Q. petraea than in Q. robur The genetic differentiation is generally higher when AFLP markers were used in comparison to microsatellites. For AFLPs, the inter-locus variance is always much higher than the intra-locus variance, and explains why it was not possible to distinguish populations using this marker system. Finally, no significant positive correlation was found between the level of within-population diversity assessed with the two markers
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