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Parallel Approaches (parallel + approach)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Parallel Approach for Solution-Phase Synthesis of 2-Quinoxalinol Analogues and Their Inhibition of LPS-Induced TNF-, Release on Mouse Macrophages in vitro.

CHEMINFORM, Issue 38 2004
Gang Liu
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

A new parallelization strategy for solving time-dependent 3D Maxwell equations using a high-order accurate compact implicit scheme,

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2006
Eugene Kashdan
Abstract With progress in computer technology there has been renewed interest in a time-dependent approach to solving Maxwell equations. The commonly used Yee algorithm (an explicit central difference scheme for approximation of spatial derivatives coupled with the Leapfrog scheme for approximation of temporal derivatives) yields only a second-order of accuracy. On the other hand, an increasing number of industrial applications, especially in optic and microwave technology, demands high-order accurate numerical modelling. The standard way to increase accuracy of the finite difference scheme without increasing the differential stencil is to replace a 2nd-order accurate explicit scheme for approximation of spatial derivatives with the 4th-order accurate compact implicit scheme. In general, such a replacement requires additional memory resources and slows the computations. However, the curl-based form of Maxwell equations allows us to construct an effective parallel algorithm with the alternating domain decomposition (ADD) minimizing the communication time. We present a new parallel approach to the solution of three-dimensional time-dependent Maxwell equations and provide a theoretical and experimental analysis of its performance. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Stem cells and diabetes treatment,

APMIS, Issue 11-12 2005
OLE DRAGSBÆK MADSEN
Diabetes mellitus types 1 and 2 are characterized by absolute versus relative lack of insulin-producing , cells, respectively. Reconstitution of a functional ,-cell mass by cell therapy , using organ donor islets of Langerhans , has been demonstrated to restore euglycaemia in the absence of insulin treatment. This remarkable achievement has stimulated the search for appropriate stem cell sources from which adequate expansion and maturation of therapeutic , cells can be achieved. This recent activity is reviewed and presented with particular focus on directed differentiation from pluripotent embryonic stem cells (versus other stem/progenitor cell sources) based on knowledge from pancreatic ,-cell development and the parallel approach to controlling endogenous ,-cell neogenesis. [source]

Rapid Matrix-Assisted Refolding of Histidine-Tagged Proteins

CHEMBIOCHEM, Issue 5 2009
Tetyana Dashivets
Abstract Matrix refolded: The formation of inclusion bodies, which are amorphous aggregates of misfolded insoluble protein, during recombinant protein expression, is one of the biggest bottlenecks in protein science. We report a stepwise, rational optimization procedure for refolding of insoluble proteins (see scheme). In comparison to refolding in-solution, this parallelized, matrix-assisted approach allows the refolding of various proteins in a fast and efficient manner. The formation of inclusion bodies (IBs),amorphous aggregates of misfolded insoluble protein,during recombinant protein expression, is still one of the biggest bottlenecks in protein science. We have developed and analyzed a rapid parallel approach for matrix-assisted refolding of recombinant His6 -tagged proteins. Efficiencies of matrix-assisted refolding were screened in a 96-well format. The developed methodology allowed the efficient refolding of five different test proteins, including monomeric and oligomeric proteins. Compared to refolding in-solution, the matrix-assisted refolding strategy proved equal or better for all five proteins tested. Interestingly, specifically oligomeric proteins displayed significantly higher levels of refolding compared to refolding in-solution. Mechanistically, matrix-assisted folding seems to differ from folding in-solution, as the reaction proceeds more rapidly and shows a remarkably different concentration dependence,it allows refolding at up to 1000-fold higher protein concentration than folding in-solution. [source]

Inorganic Materials and Ionic Liquids: Large-scale Nanopatterning of Single Proteins used as Carriers of Magnetic Nanoparticles (Adv. Mater.

ADVANCED MATERIALS, Issue 5 2010
5/2010)
Ricardo Garcia, Eugenio Coronado, and co-workers demonstrate on p. 588 large-scale patterning of single ferritin molecules by sequential (atomic force microscopy local oxidation) and parallel approaches (lithographically controlled wetting). The nanopattern size matches the size of the protein (,10 nm). Electrostatic interactions, capillary forces, surface functionalization, and nanolithography are used to achieve the desired protein organization. [source]

Large-scale Nanopatterning of Single Proteins used as Carriers of Magnetic Nanoparticles

ADVANCED MATERIALS, Issue 5 2010
Ramsés V. Martínez
Patterning of single ferritin molecules by sequential (atomic force microscopy local oxidation) and parallel approaches (lithographically controlled wetting). The nanopattern size matches the size of the protein (,10 nm). Electrostatic interactions, capillary forces, surface functionalization, and nanolithography are used to achieve the desired protein organization. [source]

Progress in the preparation of peptide aldehydes via polymer supported IBX oxidation and scavenging by threonyl resin,

JOURNAL OF PEPTIDE SCIENCE, Issue 3 2005
Gerhard Sorg
Abstract Peptide aldehydes are of interest due to their inhibitory properties toward numerous classes of proteolytic enzymes such as caspases or the proteasome. A novel access to peptide aldehydes is described using a combination of solid phase peptide synthesis with polymer-assisted solution phase synthesis based on the oxidation of peptide alcohols with a mild and selective polymer-bound IBX derivative. The oxidation is followed by selective purification via scavenging the peptide aldehyde in a capture-release procedure using threonine attached to an aminomethyl resin. Peptide aldehydes are obtained in excellent purity and satisfying yield. The optical integrity of the C -terminal residue is conserved in a high degree. The procedures are compatible with the use of common side-chain protecting groups. The potential for using the method in parallel approaches is very advantageous. A small collection of new and known peptide aldehydes has been tested for inhibitory activity against caspases 1 and 3. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd. [source]

Are Mechanistic and Statistical QSAR Approaches Really Different?

MOLECULAR INFORMATICS, Issue 6-7 2010
MLR Studies on 158 Cycloalkyl-Pyranones
Abstract Two parallel approaches for quantitative structure-activity relationships (QSAR) are predominant in literature, one guided by mechanistic methods (including read-across) and another by the use of statistical methods. To bridge the gap between these two approaches and to verify their main differences, a comparative study of mechanistically relevant and statistically relevant QSAR models, developed on a case study of 158 cycloalkyl-pyranones, biologically active on inhibition (Ki) of HIV protease, was performed. Firstly, Multiple Linear Regression (MLR) based models were developed starting from a limited amount of molecular descriptors which were widely proven to have mechanistic interpretation. Then robust and predictive MLR models were developed on the same set using two different statistical approaches unbiased of input descriptors. Development of models based on Statistical I method was guided by stepwise addition of descriptors while Genetic Algorithm based selection of descriptors was used for the Statistical II. Internal validation, the standard error of the estimate, and Fisher's significance test were performed for both the statistical models. In addition, external validation was performed for Statistical II model, and Applicability Domain was verified as normally practiced in this approach. The relationships between the activity and the important descriptors selected in all the models were analyzed and compared. It is concluded that, despite the different type and number of input descriptors, and the applied descriptor selection tools or the algorithms used for developing the final model, the mechanistical and statistical approach are comparable to each other in terms of quality and also for mechanistic interpretability of modelling descriptors. Agreement can be observed between these two approaches and the better result could be a consensus prediction from both the models. [source]