Search results for "Effects"

Investigation of the Enantioselectivity Observed in Epoxidation Reactions Catalysed by Bis‐Strapped Chiral Porphyrins Derived from L ‐Proline

2002

The enantiomeric excesses obtained during the epoxidation reactions of p-chlorostyrene or 1,2-dihydronaphthalene catalysed by two different series of chiral porphyrins are reported. An attempt is made to correlate the enantioselectivity with the steric hindrance generated by the straps of these catalysts. It is shown that this steric hindrance is influenced by the nature of the strap and that it can be approximated. Additionally, the same strap is tethered in two different fashions on each side of the porphyrin, leading to either D2- or C2-symmetrical catalysts, for which the two sides are identically functionalised.

Influence of structural factors and enzyme type on the reactivity and enantioselectivity of the enzymatic esterification of bicyclic meso dialcohols

1992

The meso dialcohols 1–7, obtained from the Diels-Alder adducts furan/maleic anhydride, furan/dimethyl acetylenedi-carboxylate, and cyclopentadiene/maleic anhydride, were subjected to enzymatic esterification in organic solvents. A mixture of the corresponding chiral monoacetates and the meso diacetates was obtained. It has been found that reaction rate and enantioselectivity markedly depend on substrate structure, temperature, enzyme type, and nature of the solvent. The presence of an oxygen bridge and an exo configuration are the two structural features which lead to the highest enantioselectivity values.

Adaptación transcultural al español y validez de contenido de 3 escalas de riesgo nutricional

2022

Introduction: There are various scales designed to determine the risk of malnutrition at hospital admission in children. However, most of these instruments are developed and published in English. Their cross-cultural adaptation and validation being mandatory in order to be used in our country. Objectives: Cross-culturally adapt three scales designed to determine the risk of malnutrition linked to the disease and determine the validity of their content. Material and methods: Cross-cultural adaptation using the translation-back-translation met-hod in accordance with the recommendations of the International Test Commission Guidelines for Translating and Adapting Tests. Content validity was mea…

Input-output feedback linearizing control of linear induction motor taking into consideration the end-effects. Part I: Theoretical analysis

2015

Abstract This first part of a paper, divided into two parts, deals with the theoretical formulation of the input–output feedback linearization (FL) control technique as to be applied to linear induction motors (LIMs). Linear induction motors, differently from rotating induction motors (RIMs), present other strong non-linearities caused by the so-called dynamic end effects, leading to a space-vector model with time-varying inductance and resistance terms and an additional braking force term. This paper, starting from a dynamic model of the LIM taking into consideration its dynamic end effects, previously developed by the same authors, defines a feedback linearization (FL) technique suited fo…

Input-Output Feedback Linearizing Control of Linear Induction Motor Taking into Consideration the End-Effects. Part II: Simulation and Experimental R…

2015

This is the second part of a paper, divided in two parts, dealing with the application of the input–output feedback linearization (FL) control technique to linear induction motors (LIMs). The first part has treated the theoretical formulation of the input–output feedback linearization control technique as to be applied to linear induction motors. This second part describes the set of tests, both in numerical simulations and experiments, performed to assess the validity of the control technique. In particular, it addresses the issues of the sensitivity of the FL control versus the LIM electrical parameters’ variations and the improvements achievable by considering the LIM dynamic end effects…

IPM-recommended insecticides harm beneficial insects through contaminated honeydew

2020

The use of some systemic insecticides has been banned in Europe because they are toxic to beneficial insects when these feed on nectar. A recent study shows that systemic insecticides can also kill beneficial insects when they feed on honeydew. Honeydew is the sugar-rich excretion of hemipterans and is the most abundant carbohydrate source for beneficial insects such as pollinators and biological control agents in agroecosystems. Here, we investigated whether the toxicity of contaminated honeydew depends on i) the hemipteran species that excretes the honeydew; ii) the active ingredient, and iii) the beneficial insect that feeds on it. HPLC-MS/MS analyses demonstrated that the systemic insec…

Interacciones entre las perspectivas situacionales y disposicionales de meta y el burnout psicológico de los tenistas junior de la élite internaciona…

2009

Resumen Desde el marco de la teoria cognitivo social de las metas de logro en este trabajo se exploran los efectos principales y de interaccion de las orientaciones de meta y del clima motivacional sobre la percepcion de los indicadores del burnout en 225 jovenes tenistas (138 chicos y 87 chicas) de la elite internacional (M edad = 15.7 ± 2.1 anos). Asimismo, se estudia la validez factorial del Eades Athlete Burnout Inventory (EABI), se examina la presencia del burnout y se analiza la relacion entre horas de entrenamiento semanales y el burnout. Los jugadores completaron las versiones inglesas o espanolas del EABI, del TEOSQ y del PMCSQ-2 en diferentes centros de entrenamiento. Los resultad…

Vulnerability Analysis of Interdependent Critical Infrastructures upon a Cyber-attack

2019

The impact of scale effects on the prevailing internet-based banking model in the US

2011

Internet-based banks use a technology-intensive production process that may benefit from scale effects as they grow larger. This article analyzes whether the predominant Internet-primary bank in the USA generates technology-based economies of scale in the period 2002–2010. There is evidence of both favorable and adverse technology-based scale effects. As the leading Internet-primary bank gets larger, the financial performance gap with traditional banks shrinks while some of its critical competitive advantages wear down. The results suggest that unless the prevailing Internet-primary bank preserves the distinctive advantages of the Internet-based business model as it improves financial perfo…

Efficacy and safety of tafluprost 0.0015% and timolol maleate 0.5% fixed combination in patients with ocular hypertension or open-angle glaucoma.

2014

Lowering intraocular pressure (IOP) is at present the only therapeutic approach to the treatment of glaucoma proven to be successful. The choice of therapy must take into account efficacy, tolerability, safety, quality of life, adherence and cost. Monotherapy fails to achieve a satisfactory IOP reduction in 40 - 75% of glaucoma patients after2 years of therapy. So far, three prostaglandin/timolol maleate 0.5% fixed combinations (FCs) are available.This review provides a background on the tafluprost-timolol FC (TTFC, Santen Oy) and its individual compounds. It summarizes the data on efficacy and safety, including comparative data with prostaglandin/timolol FCs already available.Tafluprost is…