Search results for "Excess"
showing 10 items of 225 documents
Estimating COVID-19-induced Excess Mortality in Lombardy, Italy.
2022
We compare the expected all-cause mortality with the observed one for different age classes during the pandemic in Lombardy, which was the epicenter of the epidemic in Italy. The first case in Italy was found in Lombardy in early 2020, and the first wave was mainly centered in Lombardy. The other three waves, in Autumn 2020, March 2021 and Summer 2021 are also characterized by a high number of cases in absolute terms. A generalized linear mixed model is introduced to model weekly mortality from 2011 to 2019, taking into account seasonal patterns and year-specific trends. Based on the 2019 year-specific conditional best linear unbiased predictions, a significant excess of mortality is estima…
Bis(oxazoline) Lewis Acid Catalyzed Aldol Reactions of PyridineN-Oxide Aldehydes—Synthesis of Optically Active 2-(1-Hydroxyalkyl)pyridine Derivatives…
2006
A new, short, and simplified procedure for the synthesis of optically active pyridine derivatives from pro-chiral pyridine-N-oxides is presented. The catalytic and asymmetric Mukaiyama aldol reaction between ketene silyl acetals and 1-oxypyridine-2-carbaldehyde derivatives catalyzed by chiral copper(II)-bis(oxazoline) complexes gave optically active 2-(hydroxyalkyl)- and 2-(anti-1,2-dihydroxyalkyl)pyridine derivatives in good yields and diastereoselectivities, and in excellent enantioselectivities-up to 99 % enantiomeric excess. As a synthetic application of the developed method, a full account for the asymmetric total synthesis of a nonnatural indolizine alkaloid is provided.
ENANTIOSELECTIVE REDUCTION OF PROCHIRAL KETONES PROMOTED BY AMINO AMIDE RUTHENIUM COMPLEXES: A DFT STUDY
2021
International audience; The origin of enantioselectivity in the reaction of chiral Ru amino amide complexes in the asymmetric transfer hydrogenation of acetophenone was investigated using DFT calculations. For the most stable active catalysts, the full free energy profiles for the reaction were calculated according to the concerted hydrogen transfer mechanism. We succeeded in reproducing the experimentally observed enantioselectivity for the studied Ru amino amide complexes. Our results indicate that the high enantioselectivity can be explained by a stabilizing CH-π interaction existing between the phenyl group of acetophenone and the aromatic substituent of the catalyst, which plays a sign…
Base Excess and Strong Ion Difference: Clinical Limitations Related to Inaccuracy
2004
Qualitätskontrolle des Base Excess (BE, mmol/l) im Blutgasanalysator
1995
Die Ermittlung des Base Excess (BE, mmol/l) im Urin
1995
Säure-Basen-Status gelagerter und gewaschener Erythrozyten
2001
Die korrekte Bestimmung des Base Excess (BE, mmol/l) im Blut
1995
The determination of mineral acidity excess in solutions containing Ga(III), Al(III), Bi(III)
2002
Abstract A new procedure is proposed to carry out volumetric determinations of the strong acid content of a solution in the presence of inorganic cations such as Ga 3+ , Al 3+ , Bi 3+ which, showing in aqueous solution an acidic behaviour, introduce non negligible interferences in these determinations. Before the acid–base titration, an equivalent amount of a ligand, such as dihydrogen ethylendiamino tetraacetate is added, in order to strongly complex the cation masking it toward the successive addition of a strong base. Interferences are thus removed, and the volumetric determination of the strong acid excess plus the hydrogen ions set free from the ligand, as a consequence of the complex …
ChemInform Abstract: Efficient Synthesis of Racemic and Chiral Alkenyl Sulfoxides by Palladium-Catalyzed Suzuki Coupling.
2010
Alkenyl sulfoxide derivatives are obtained in high yields through a palladium-catalyzed Suzuki/Miyaura cross-coupling reaction of racemic and chiral 1-halo sulfoxides with aryl and alkenyl boronic acids. Chiral substrates react with no loss of optical purity and high optical yields. The reaction takes place with different palladium catalysts, such as Pd(PPh 3 ) 4 or Pd(OAc) 2 /DABCO. Although nitrogen ligands like DABCO lead to an active palladium catalyst, they are less effective than the phosphine ones.