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Coupling Process (coupling + process)

Distribution by Scientific Domains
Chemistry54%
Medical Sciences18%

Selected Abstracts

ChemInform Abstract: A New Focused Microwave Approach to the Synthesis of Amino-Substituted Pyrroloisoquinolines and Pyrroloquinolines via a Seqential Multi-Component Coupling Process.

CHEMINFORM, Issue 41 2008
Mark D. Hopkin
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Synthesis of Hydrophenanthrenes Through a "Green" Fischer Carbene,Alkyne Coupling Process.

CHEMINFORM, Issue 45 2005
Rongti Li
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

A General and Special Catalyst for Suzuki,Miyaura Coupling Processes

ANGEWANDTE CHEMIE, Issue 34 2010
Wenjun Tang Dr.
Biaryl-Monophosphorliganden mit einem 2,3-Dihydrobenzo[d][1,3]oxaphosphol-Gerüst ergeben hoch effiziente palladiumkatalysierte Suzuki-Miyaura-Kreuzkupplungen mit verschiedenartigen Substraten. Der Ligand 1 eignet sich außerordentlich gut für Kupplungen von sterisch stark gehinderten Arylboronsäuren. [source]

A Rationally Designed Universal Catalyst for Suzuki,Miyaura Coupling Processes.

CHEMINFORM, Issue 29 2004
Shawn D. Walker
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Three Phase Microemulsion/Sol,Gel System for Aqueous C,C Coupling of Hydrophobic Substrates

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2008
Dmitry Tsvelikhovsky
Abstract Heck, Stille, Suzuki and three-component coupling reactions with hydrophobic substrates have been carried out in water. The substrates are initially transformed by a general procedure into a microemulsion, which consists of nearly 90,% water with the aid of sodium dodecyl sulfate and either PrOH or BuOH. The surfactant carries the molecules of the substrates to Pd(OAc)2 entrapped within a hydrophobicitized silica sol,gel matrix where the coupling between the substrates is assumed to take place. The products are then returned by the surfactant into the microemulsion from which it can be released. The immobilized palladium catalyst is leach proof and recyclable. It can be used in various coupling processes at least six times without loss of activity. Experiments with D2O have revealed that the water does not take part in the coupling process, but it has an effect on the pore size of the sol,gel matrix, which hosts the palladium catalyst. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Osteocytes in the pathogenesis of osteoporosis

GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2008
Kyoji Ikeda
Bone is continuously renewed by bone resorption and subsequent bone formation, a coupling process that maintains the quality as well as the quantity of bone. It is widely accepted that osteoporosis develops when bone resorption exceeds bone formation, and the treatment as well as diagnosis has been targeted to two major cell types, osteoclasts and osteoblasts. Inside bone is a network of the third cell type, osteocytes, the physiological function of which has long remained an enigma. We have developed a transgenic mouse model in which inducible and specific ablation of osteocytes can be achieved in vivo, and here use it to demonstrate that osteocytes serve an important function in regulating the activities of osteoblasts and osteoclasts, while sensing and transducing the mechanical forces exerted on bone. Thus, osteocytes should provide an attractive target for the development of new types of mechanotransduction-based therapeutics and diagnostics for osteoporosis. [source]

Acoustic phonons in InSb probed by time-resolved X-ray diffraction

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 12 2006
A. Morak
Abstract Acoustical phonons in InSb were induced with femtosecond light pulses and probed by diffraction of ultrashort X-ray pulses in the crystal lattice. The time dependent transient X-ray diffraction signal due to elastic lattice deformation was measured with subpicosecond resolution. The elastic lattice deformation depends on the temporal evolution of the energy transfer from excited electrons in the semiconductor into the lattice. As already shown in previous investigation a conventional thermoelastic model is not sufficient to describe this coupling process. Here a complex simulation including a two temperature model of the electron and lattice as well as the microscopic behavior of the electron plasma is applied to explain important effects like thermal carrier diffusion and band gap deformation found in the lattice deformation experiments. When this model is used, with realistic values for both pump laser fluences and bulk material constants, excellent agreement between the experimentally observed time dependent lattice deformation and calculated values is obtained throughout the observation period. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Chloride ATPase pumps in nature: do they exist?

BIOLOGICAL REVIEWS, Issue 2 2003
GEORGE A. GERENCSER
ABSTRACT Five widely documented mechanisms for chloride transport across biological membranes are known: anioncoupled antiport, Na+ and H+ -coupled symport, Cl, channels and an electrochemical coupling process. These transport processes for chloride are either secondarily active or are driven by the electrochemical gradient for chloride. Until recently, the evidence in favour of a primary active transport mechanism for chloride has been inconclusive despite numerous reports of cellular Cl, -stimulated ATPases coexisting, in the same tissue, with uphill ATP-dependent chloride transport. Cl, -stimulated ATPase activity is a ubiquitous property of practically all cells with the major location being of mitochondrial origin. It also appears that plasma membranes are sites of Cl, -stimulated ATPase pump activity. Recent studies of Cl, -stimulated ATPase activity and ATP-dependent chloride transport in the same plasma membrane system, including liposomes, strongly suggest a mediation by the ATPase in the net movement of chloride up its electrochemical gradient across the plasma membrane structure. Contemporary evidence points to the existence of Cl, -ATPase pumps; however, these primary active transporters exist as either P-, F- or V-type ATPase pumps depending upon the tissue under study. [source]

3252: Basic mechanisms and factors influencing the neurovascular coupling in the eye

ACTA OPHTHALMOLOGICA, Issue 2010
G GARHOFER
Neuro-vascular coupling is a basic physiological mechanism in the eye that allows for adapting retinal and optic nerve head blood flow to changing metabolic demands, induced by an increase in neural activity. Despite many efforts, the mechanisms that leads to this coupling process are largely unknown. Among others, nitric oxide seems to play an important role in the vasodilatory answer. It has been shown that the unspecific blockade of nitric-oxide syntheses leads to a pronounced reduction of flicker induced vasodilatation in healthy subjects. This indicates that nitric oxide plays an important role in this signaling cascade. Additionally, there is evidence that astrocytes act as a mediator between ganglion cells and blood vessels in the retina. This hypothesis is strengthened by the observation that the presence and distribution of retinal astrocytes correlates with the presence and distribution of retinal blood vessels. This talk will summarize the concept of neuro-vascular coupling in the eye and give an overview about our current understanding of the mechanisms and factors involved in this process. [source]

Three Phase Microemulsion/Sol,Gel System for Aqueous C,C Coupling of Hydrophobic Substrates

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2008
Dmitry Tsvelikhovsky
Abstract Heck, Stille, Suzuki and three-component coupling reactions with hydrophobic substrates have been carried out in water. The substrates are initially transformed by a general procedure into a microemulsion, which consists of nearly 90,% water with the aid of sodium dodecyl sulfate and either PrOH or BuOH. The surfactant carries the molecules of the substrates to Pd(OAc)2 entrapped within a hydrophobicitized silica sol,gel matrix where the coupling between the substrates is assumed to take place. The products are then returned by the surfactant into the microemulsion from which it can be released. The immobilized palladium catalyst is leach proof and recyclable. It can be used in various coupling processes at least six times without loss of activity. Experiments with D2O have revealed that the water does not take part in the coupling process, but it has an effect on the pore size of the sol,gel matrix, which hosts the palladium catalyst. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Modelling of elastoplastic damage in concrete due to desiccation shrinkage

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 8 2002
F. Bourgeois
We present a numerical modelling of elastoplastic damage due to drying shrinkage of concrete in the framework of mechanics of partially saturated porous media. An elastoplastic model coupled with isotropic damage is first formulated. Two plastic flow mechanisms are involved, controlled by applied stress and suction, respectively. A general concept of net effective stress is used in take into account effects of capillary pressure and material damage on stress-controlled plastic deformation. Damage evolution depends both on elastic and plastic strains. The model's parameters are determined or chosen from relevant experimental data. Comparisons between numerical simulations and experimental data are presented to show the capacity of model to reproduce mains features of concrete behaviour under mechanical loading and during drying shrinkage of concrete. An example of application concerning drying of a concrete wall is finally presented. The results obtained allow to show potential capacity of proposed model for numerical modelling of complex coupling processes in concrete structures. Copyright © 2002 John Wiley & Sons, Ltd. [source]