Search results for "synthesis"

On speeding up synthesis and prediction of functions

1974

In Silico Finite Element Modeling of Stress Distribution in Osteosynthesis after Pertrochanteric Fractures

2022

A stabilization method of pertrochanteric femur fractures is a contentious issue. Here, we assess the feasibility of rapid in silico 2D finite element modeling (FEM) to predict the distribution of stresses arising during the two most often used stabilization methods: gamma nail fixation (GNF) and dynamic hip screw (DHS). The modeling was based on standard pre-surgery radiographs of hip joints of 15 patients with pertrochanteric fractures of type A1, A2, and A3 according to the AO/OTA classification. The FEM showed that the stresses were similar for both GNF and DHS, with the medians ranging between 53–60 MPa and consistently lower for A1 than A3 fractures. Stresses also appeared in the fixa…

Rod–coil copolymers from oligo(p-benzamide) foldamers

2007

Self assembling rod–coil copolymers were synthesized in which oligo(p-benzamide) rods up to the octamer were prepared via iterative solution synthesis employing the acid labile 2,4-dimethoxybenzyl amide protective group.

Pigment patterns in mutants affecting the biosynthesis of pteridines and xanthommatin in Drosophila melanogaster.

1986

Eye-color mutants of Drosophila melanogaster have been analyzed for their pigment content and related metabolites. Xanthommatin and dihydroxanthommatin (pigments causing brown eye color) were measured after selective extraction in acidified butanol. Pteridines (pigments causing red eye color) were quantitated after separation of 28 spots by thin-layer chromatography, most of which are pteridines and a few of which are fluorescent metabolites from the xanthommatin pathway. Pigment patterns have been studied in 45 loci. The pteridine pathway ramifies into two double branches giving rise to isoxanthopterin, “drosopterins,” and biopterin as final products. The regulatory relationship among the …

Diorganotin(IV) complexes ofD-galacturonic acid: solid-state and solution-phase structural study

2003

Three diorganotin(IV) complexes of D-galacturonic acid (H2GalA; R = Me, n-Bu, Ph), two of which are new derivatives (R = Me, Ph), have been synthesized and their solid-state and solution-phase investigated by IR, Mossbauer, 1H, 13C and 119Sn NMR spectroscopy. The FTIR data suggest that H2GalA, in the dialkyltin derivatives, behaves as a dianionic ligand, coordinating the tin(IV) atom through an ester-type carboxylate and deprotonated alcoholic hydroxo groups, whereas a bridging carboxylate occurs in the diphenyltin(IV) complex. Octahedral and trigonal bipyramidal local geometries on tin(IV) atoms are proposed for dialkyltin(IV)GalA and diphenyltin(IV)GalA complexes respectively on the basis…

MICROWAVE-ASSISTED FUNCTIONALIZATION OF HALLOYSITE NANOTUBE SURFACE

2014

Halloysite, Al2Si2O5·2H2O, is a naturally occurring two-layered alluminosilicate, chemically similar to kaolin, which has a predominantly high-aspect-ratio hollow tubular structure in the submicrometer range and an internal diameter in the nanometer range. The size of halloysite nanotubes (HNTs), generally varies from 50 to 70 nm in external diameter, ca. 15 nm diameter lumen, and 0.5 to 1 μm in length. Halloysite tubes have aluminol (Al-OH) groups on the internal surface and siloxan groups (Si-O-Si) on the external surface. The very large diameter of the halloysite lumen makes it potentially suitable for the accommodation of a range of guests. In recent reports, for example, the mesoporous…

A Systematic Review and Metasynthesis of Qualitative Studies on the Competencies of Health and Rehabilitation Science Educators

2020

Background. Health and rehabilitation science educators’ competence greatly influences students’ professional development in a changing world. To ensure the availability of qualified health and rehabilitation science educators in the future, there is a need for continuous reforms in this sector to develop the educators’ competence in this sector. Objective. The aim of this systematic review was to find new evidence on educators’ experiences of their competence in health and rehabilitation science higher education. Methods. The study was a systematic review of previous peer-reviewed qualitative studies. The inclusion criteria were planned according to PICo: health and rehabilitation science …

Asymmetric Synthesis of Fluorinated Isoindolinones through Palladium-Catalyzed Carbonylative Amination of Enantioenriched Benzylic Carbamates

2015

The asymmetric synthesis of fluorinated isoindolinones has been achieved by a palladium-catalyzed aminocarbonylation reaction of the corresponding -fluoroalkyl o-iodobenzylamines. A base-mediated anti -hydride elimination process was suggested to explain the partial erosion of the optical purity observed in some cases. This mechanistic rationale enabled the minimization of this partial racemization by fine-tuning the pK(a) of the base.

Organocatalytic approach to benzofused nitrogen-containing heterocycles: enantioselective total synthesis of (+)-angustureine.

2008

Simple two-step synthesis of 2,4-disubstituted pyrroles and 3,5-disubstituted pyrrole-2-carbonitriles from enones

2014

The cyclocondensation of enones with aminoacetonitrile furnishes 3,4-dihydro-2H-pyrrole-2-carbonitriles which can be readily converted to 2,4-disubstituted pyrroles by microwave-induced dehydrocyanation. Alternatively, oxidation of the intermediates produces 3,5-disubstituted pyrrole-2-carbonitriles.