Search results for "ASTER"
showing 10 items of 2223 documents
Synthesis of oligodeoxynucleotides containing diastereomeric dihydrodiol epoxide-N6-deoxyadenosine adducts of polycyclic aromatic hydrocarbons
1993
Abstract A generally applicable route is reported for the synthesis of oligodeoxynucleotides which contain structurally defined N 6 -deoxyadenosine adducts, derived from sterically highly hindered dihydrodiol epoxides of polycyclic aromatic hydrocarbons (PAH).
Stereocontrolled synthesis of five diastereomers of trimethyl 3-aminocyclopentane-1,2,4-tricarboxylates
2013
Abstract The sterically controlled oxidative cleavage of N - protected di exo - and di endo -substituted norbornene β-amino acids/esters resulted in four trimethyl 3-aminocyclopentane-1,2,4-carboxylate diastereomers. The sodium methoxide mediated isomerization of the four diastereomers in all cases yielded the thermodynamically most stable all- trans stereoisomer as a single product.
ChemInform Abstract: Synthesis of Oligodeoxynucleotides Containing Diastereomeric Dihydrodiol Epoxide-N6-Deoxyadenosine Adducts of Polycyclic Aromati…
2010
Abstract A generally applicable route is reported for the synthesis of oligodeoxynucleotides which contain structurally defined N 6 -deoxyadenosine adducts, derived from sterically highly hindered dihydrodiol epoxides of polycyclic aromatic hydrocarbons (PAH).
Planar-Chiral 1,1 '-Diboryl Metallocenes: Diastereoselective Synthesis from Boryl Cyclopentadienides and Spin Density Analysis of a Diborylcobaltocene
2017
International audience; The reaction of nonsubstituted alkali metal cyclopentadienides with haloboranes leads to similar to 90:10 mixtures of isomeric diene products that can be deprotonated to give simple boryl cyclopentadienides. We extended this transformation to the sterically hindered lithium tert-butylcyclopentadienide 1 using FBMe(s)2 (Mes = 2,4,6-trimethylphenyl) and ClBCy2 as electrophiles. The boryl group is selectively introduced in the remote position to minimize steric congestion. The new boryl dienes are obtained as mixtures of isomers, and subsequent deprotonation with MeLi or LiHMDS affords the lithium 1,3-disubstituted cyclopentadienides Sa,b in yields over 95%. Direct asse…
Contribution à l’étude de la fraction insaponifiable de trois huiles d’olive issues des variétés Guasto, Rougette et Blanquette plantés dans l’est al…
2010
The sterol profile of three Algerian virgin olive oils produced from Guasto, Blanquette and Rougette cultivar’s, varieties grown in the East of the country, was established by gas chromatography using a flame ionization detector and coupled to mass spectrometry. Four sterol compounds were identified and characterized in the three oils which are, sitosterol always predominant (43-66%), delta 5-avenasterol (8-13%), stigmasterol (≤ 1,5%) and campesterol (1-2%); one methyl sterol (4-methylsterol) : citrostadienol (4-7%) and two triterpenic alcohols : 24-methylene cycloartanol (10-33%) and cycloartenol (3-13%). These results vary according to campany and variety. Our study shows that most of the…
Sterol Composition in Infant Formulas and Estimated Intake.
2015
Sterol contents in infant formulas (IFs) from the European market were determined, and their intakes by infants between 0 and 6 months were evaluated. Total animal sterols (mg/100 mL) ranged from 1.71 to 5.46, cholesterol being the main animal sterol (1.46-5.1). In general, cholesterol and desmosterol were lower than the human milk (HM) values indicated by other authors. Total plant sterol (mg/100 mL) ranged from 3.1 to 5.0. β-Sitosterol, the most abundant phytosterol, ranged from 1.82 to 3.01, followed by campesterol (0.72-1.15), stigmasterol (0.27-0.53), and brassicasterol (0.14-0.28). Cholesterol intake (mg/day) ranged from 9 to 51 and plant sterol intake (mg/day) from 19 to 50. The ster…
The roads of ‘excellence’ in Central and Eastern Europe
2017
The aim of the article is to explore the impact of excellence as a powerful policy idea in the context of recent and contemporary developments in three selected Central and Eastern European countries, namely, the Czech Republic, Poland and Ukraine. More specifically, we explore how excellence as a ‘global script’ was translated by policy makers into local contexts with institutionalized practices. It shows that the translation of the idea of excellence involved the rise of a series of novel policy measures such as long-term strategic funding and the establishment of various pertinent schemes (e.g. flagship universities, centres of excellence). By doing so, the analysis – which is comparativ…
A computational model for motor learning in insects
2013
The aim of this paper is to propose a computational model, inspired by Drosophila melanogaster, able to handle problems related to motor learning. The role of the Mushroom Bodies and the Central Complex in solving this problem is analyzed and plausible biologically inspired models are proposed. The designed computational models have been evaluated in simulation using a dynamic structure inspired by the fruit fly. The obtained results open the way to new neurobiological experiments focused to better understand the underlined mechanisms involved, to verify the feasibility of the hypotheses formulated and the significance of the obtained results.
Explaining the Formation Rates of Post-Communist Interest Organizations: Density Dependence and Political Opportunity Structure
2020
This article presents an analysis of the formation of organized interest groups in the post-communist context and organizational populations over time. We test two theories that shed doubt on whether vital rates of interest groups are explained by individual incentives, namely, the political opportunity structure and population ecology theory. Based on an analysis of the energy policy and higher education policy organizations active at the national level in Hungary, Poland, and Slovenia, we find that while the period of democratic and economic transition indeed opened up the opportunity structure for organizational formations, it by no means presented a clean slate. Communist-era successor…
Suburban Fertility and Metropolitan Cycles: Insights from European Cities
2021
Being largely diversified along the urban–rural gradient, fertility gaps have demonstrated to fuel metropolitan expansion, contributing to natural population growth and social change. In this direction, population dynamics and economic transformations have continuously shaped urban cycles in Europe. Assuming suburban fertility to be a relevant engine of metropolitan growth, the present study investigates and discusses the intrinsic relationship between fertility transitions and urban expansion, focusing on European metropolitan regions. An average crude birth rate referring to the last decade (2013–2018) was estimated from official statistics at 671 Functional Urban Areas (FUAs, Eurostat Ur…