Search results for "reactions"
showing 10 items of 631 documents
The Greenland shark Somniosus microcephalus—Hemoglobins and ligand-binding properties
2017
A large amount of data is currently available on the adaptive mechanisms of polar bony fish hemoglobins, but structural information on those of cartilaginous species is scarce. This study presents the first characterisation of the hemoglobin system of one of the longest-living vertebrate species (392 +/- 120 years), the Arctic shark Somniosus microcephalus. Three major hemoglobins are found in its red blood cells and are made of two copies of the same a globin combined with two copies of three very similar beta subunits. The three hemoglobins show very similar oxygenation and carbonylation properties, which are unaffected by urea, a very important compound in marine elasmobranch physiology.…
Theoretical Investigation of the Low-Energy States of CpMoCl(PMe 3 ) 2 and Their Role in the Spin-Forbidden Addition of N 2 and CO
2003
International audience; A recent computational investigation of Jahn−Teller effects in unsaturated 16-electron d4d6 [CpMLn] complexes (Abu-Hasanayn, F.; Cheong, P.; Oliff, M. Angew. Chem.2002, 41, 2120) highlighted the typical presence of two spin-triplet and two singlet states of competing stability in these complexes and pointed out the necessity to account for more than one electronic state in studies thereof. Consequently, we have reinvestigated the addition of N2 to all the four low-energy states of CpMoCl(PH3)2, a reaction for which previously only one singlet and one triplet state have been considered (Keogh, D. W.; Poli, R. J. Am. Chem. Soc.1997, 119, 2516). The present study was pe…
Squaramide-Catalyzed Asymmetric aza-Friedel-Crafts/N,O-Acetalization Domino Reactions Between 2-Naphthols and Pyrazolinone Ketimines
2017
N-Boc ketimines derived from pyrazolin-5-ones were explored to develop an unprecedented domino aza-Friedel-Crafts/N,O-acetalization reaction with 2-naphthols. The novel method requires a catalyst loading of only 0.5 mol % of a bifunctional squaramide catalyst, is scalable to gram amounts, and provides a new series of furanonaphthopyrazolidinone derivatives bearing two vicinal tetra-substituted stereogenic centers in excellent yields (95-98 %) and stereoselectivity (>99:1 d.r. and 97-98 % ee). A different reactivity was observed in the case of 1-naphthols and other electron-rich phenols, which led to the aza-Friedel-Crafts adducts in 70-98 % yield and 47-98 % ee.
2D Hydro-Mechanical-Chemical Modeling of (De)hydration Reactions in Deforming Heterogeneous Rock: The Periclase-Brucite Model Reaction
2020
Deformation at tectonic plate boundaries involves coupling between rock deformation, fluid flow, and metamorphic reactions, but quantifying this coupling is still elusive. We present a new two-dimensional hydro-mechanical-chemical numerical model and investigate the coupling between heterogeneous rock deformation and metamorphic (de)hydration reactions. We consider linear viscous compressible and power-law viscous shear deformation. Fluid flow follows Darcy's law with a Kozeny-Carman type permeability. We consider a closed isothermal system and the reversible (de)hydration reaction: periclase and water yields brucite. Fluid pressure within a circular or elliptical inclusion is initially bel…
The Plant Defense Elicitor Cryptogein Stimulates Clathrin-Mediated Endocytosis Correlated with Reactive Oxygen Species Production in Bright Yellow-2 …
2008
Abstract The plant defense elicitor cryptogein triggers well-known biochemical events of early signal transduction at the plasma membrane of tobacco (Nicotiana tabacum) cells, but microscopic observations of cell responses related to these early events were lacking. We determined that internalization of the lipophilic dye FM4-64, which is a marker of endocytosis, is stimulated a few minutes after addition of cryptogein to tobacco Bright Yellow-2 (BY-2) cells. This stimulation is specific to the signal transduction pathway elicited by cryptogein because a lipid transfer protein, which binds to the same receptor as cryptogein but without triggering signaling, does not increase endocytosis. To…
Anhydrobiosis: Inside yeast cells
2018
International audience; Under natural conditions yeast cells as well as other microorganisms are regularly subjected to the influence of severe drought, which leads to their serious dehydration. The dry seasons are then changed by rains and there is a restoration of normal water potential inside the cells. To survive such seasonal changes a lot of vegetative microbial cells, which belong to various genera and species, may be able to enter into a state of anhydrobiosis, in which their metabolism is temporarily and reversibly suspended or delayed. This evolutionarily developed adaptation to extreme conditions of the environment is widely used for practical goals - for conservation of microorg…
A case of cefditoren‐induced Acute Generalized Exanthematous Pustulosis during COVID‐19 pandemics. Severe Cutaneous Adverse Reactions (SCARs) are an …
2020
Abstract We read with interest the article by Recalcati et al. about the report of cutaneous manifestations in COVID‐19 patients. We would like to highlight that some potentially severe manifestations in these patients are not directly related to the coronavirus but to the medications administered.
Antiepileptic drug reduction and increased risk of stimulation-evoked focal to bilateral tonic-clonic seizure during cortical stimulation in patients…
2017
Introduction: Stimulation-evoked focal to bilateral tonic-clonic seizure (FBTCS) can be a stressful and possibly harmful adverse event for patients during cortical stimulation (CS). We evaluated if drug load reduction of anti epileptic drugs (AEDs) during CS increases the risk of stimulation-evoked FBTCS. Material and methods: In this retrospective cohort study, we searched our local database for patients with drug resistant epilepsy who underwent invasive video-EEG monitoring and CS in the University Hospital la Fe Valencia from January 2006 to November 2016. The AED drug load was calculated with the defined daily dose. We applied a uni- and multivariate logistic regression model to estima…
Primary prophylaxis of invasive fungal infections with posaconazole or itraconazole in patients with acute myeloid leukaemia or high-risk myelodyspla…
2017
This is an observational-retrospective study comparing the real-world outcomes associated with posaconazole vs. itraconazole as prophylaxis treatments. Two hundred and ninety-three patient admissions attributable to 174 patients were included in the study. Patients were treated with itraconazole (n = 114 admissions; 39%) or posaconazole (n = 179; 61%). Antifungal prophylaxis failure (APF) due to treatment-related adverse events (in 34 out of 293 patient admissions; 11.6%) was more frequent in the posaconazole group (6.1% vs. 15.1%; P = 0.024). There were 9 patient admissions for episodes of APF due to probable/proven breakthrough fungal infection (primary endpoint): 6 and 3 in the itraconaz…
Transferability of PCR-based diagnostic protocols: An international collaborative case study assessing protocols targeting the quarantine pine pathog…
2019
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