Search results for "synthesis"

Primäre Ellenbogenprothese bei distalen Humerustrümmerfrakturen

2004

The use of hip- and shoulder arthroplasty in elderly patients for grossly displaced intraarticular fractures is being more and more accepted. Total elbow replacement (TER) has not been considered as an option for the treatment of extensively comminuted fractures of the distal humerus because surgeons feel the outcome is not predictable after TER generally. On the basis of a Medline literature research of this issue and the documented results based on the improvement of the designs of the implants, operative technique and the selection of patients, TER has a definite role in the treatment of some fractures of the distal humerus. We retrospectively reviewed forty-nine acute distal humeral fra…

Die Kleinfragment-Doppelplattenosteosynthese bei C1- bis C3-Frakturen des Pilon tibiale

2008

Intra-articular fractures of the tibial pilon always have been a challenge for the surgeon and his operative technique. With conservative or operative management, we have to take care of destroyed articular surfaces and traumatised soft tissues. Therefore, tibial pilon fractures are known in the literature as complicated lesions with a high rate of complications. Between 1993 and 2001 twenty-one patients who were between 18 and 65 years old and suffered a monotrauma of the tibial pilon of the type C1 to C3 of the AO classification, were treated with a staged reconstruction. Stabilisation was done by small-fragment double plate osteosynthesis. In this retrospective study, we could review 17 …

How Important is the Reproduction Technique for the Perception of Spaciousness in Music?

2016

Sound fields are preferred when spaciousness is perceived. “Spaciousness means that auditory events, in a characteristic way, are themselves perceived as being spread out in an extended region of space”. The author’s former study (2012) investigated the perception of spaciousness of five musical genres. Participants evaluated spaciousness while listening to music with loudspeakers. Resulting, these genres allowed classifications of spatial features such as “big”, “wide” and “open”. A new idea of conducting listening tests has arisen using wave field synthesis instead of headphones. Firstly, this study aims to reveal the perceptional characteristics of spaciousness in music itself with headp…

Variants of the

2019

The Gram-positive soil bacterium Bacillus subtilis relies on the glutamine synthetase and the glutamate synthase for glutamate biosynthesis from ammonium and 2-oxoglutarate. During growth with the carbon source glucose, the LysR-type transcriptional regulator GltC activates the expression of the gltAB glutamate synthase genes. With excess of intracellular glutamate, the gltAB genes are not transcribed because the glutamate-degrading glutamate dehydrogenases (GDHs) inhibit GltC. Previous in vitro studies revealed that 2-oxoglutarate and glutamate stimulate the activator and repressor function, respectively, of GltC. Here, we have isolated GltC variants with enhanced activator or repressor fu…

Radiation engineered nanogels as platform for next-generation of medical diagnostics and therapeutics

2010

Preparation of Nd:YAG Nanopowder in a Confined Environment

2007

Nanopowder of yttrium aluminum garnet (YAG, Y3Al5O12) doped with neodymium ions (Nd:YAG) was prepared in the water/cetyltrimethylammonium bromide/1-butanol/n-heptane system. Aluminum, yttrium, and neodymium nitrates were used as starting materials, and ammonia was used as a precipitating agent. Coprecipitate hydroxide precursors where thermally treated at 900 degrees C to achieve the garnet phase. The starting system with and without reactants was characterized by means of the small-angle neutron scattering technique. The system, without reactants, is constituted by a bicontinuous structure laying near the borderline with the lamellar phase region. The introduction of nitrates stabilizes th…

Surface modification of poly(ethylene-co-acrylic acid) with amino-functionalized silica nanoparticles

2011

In this work we studied the possibility to achieve a hybrid-surface through the modification, via a facile wet chemical process, of the surface of films of poly(ethylene-co-acrylic acid) (EAA) with amino-modified silica nanoparticles. Films of EAA were preliminarily activated by the introduction of -COCl groups on their surface. Silica nanoparticles were thereafter covalently bound on the polymeric surface as confirmed by FTIR, ATR-FTIR, XPS, NMR and SEM determinations. The nanoparticles formed a multilayer on the film surface and covered almost uniformly the whole film surface. Direct measurements of superficial amino groups by titration allowed us to detect a concentration of about 18 nmo…

Pb-PbOHCl Composite Nanowires Synthesized by Galvanic Deposition in Template

2019

In this paper, we report a detailed study on the synthesis of composite nanowires of Pb-PbOHCl via galvanic deposition into the pores of a membrane acting as a template. PbOHCl deposition quantitatively occurs as the solution pH exceeds the value of about 4.12. Simultaneously, owing to the galvanic coupling, electro-deposition of lead occurs, so composite nanowires were formed. The role of different parameters controlling the kinetic evolution of the process, such as oxygen bubbling, solution pH, surface area and type of sacrificial anode were investigated one at a time. The results suggest that every modification accelerating the alkalization of the solution inside the template pores favor…

A Catalyst Designed for the Enantioselective Construction of Methyl- and Alkyl-Substituted Tertiary Stereocenters

2015

Tertiary methyl-substituted stereocenters are present in numerous biologically active natural products. Reported herein is a catalytic enantioselective method for accessing these chiral building blocks using the Mukaiyama-Michael reaction between silyl ketene thioacetals and acrolein. To enable remote enantioface control on the nucleophile, a new iminium catalyst, optimized by three-parameter tuning and by identifying substituent effects on enantioselectivity, was designed. The catalytic process allows rapid access to chiral thioesters, amides, aldehydes, and ketones bearing an α-methyl stereocenter with excellent enantioselectivities, and allowed rapid access to the C4-C13 segment of (-)-b…

Synthesis and Rearrangement of 2-(N-Methyl-N-nitroamino)-4-phenylthiazole

2007

2-(N-Methyl-N-nitroamino)-4-phenylthiazole (5) was prepared and rearranged in aqueous dioxane under influence of sulphuric acid of various concentrations. 2-(N-Methylamino)- 5-nitro-4-phenylthiazole (6) was the only product up to 50% acid concentration. At higher acidities, significant amounts of nitro derivatives 3b and3c, substituted in benzene ring, were also formed. The result indicates that migration of the N-nitro group occurs on the intramolecular path, however, in concentrated sulphuric acid, formation of nitronium ion and ring nitration also takes place.