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Synthesis Approach (synthesis + approach)
Selected AbstractsA Facile Synthesis Approach to C8 -Functionalized Magnetic Carbonaceous Polysaccharide Microspheres for the Highly Efficient and Rapid Enrichment of Peptides and Direct MALDI-TOF-MS AnalysisADVANCED MATERIALS, Issue 21 2009Hemei Chen Biocompatible C8 -functionalized magnetic carbonaceous polysaccharide microspheres are synthesized via a facile, low-cost, and large-scale route, and their use for the enrichment of peptides from protein digest mixtures is presented. The process of enrichment is very simple, quick, and efficient. Peptides loaded onto the C8 -functionalized magnetic carbonaceous polysaccharide microspheres can be directly analyzed by MALDI-TOF-MS without prior elution from the microspheres. [source] Microwave-Enhanced Palladium-Catalyzed Coupling Reactions: A Diversity-Oriented Synthesis Approach to Functionalized Flavones.CHEMINFORM, Issue 13 2007Richard J. Fitzmaurice 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, please click on HTML or PDF. [source] ChemInform Abstract: Regioselective Synthesis Approaches Towards 1,2,8,9-Tetraazadispiro[4.1.4.2]trideca-2,9-dien-6-ones of Potential Antimicrobial Properties.CHEMINFORM, Issue 37 2009Adel S. Girgis 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] Novel Crosslinking of High-order and Multiple Copper Twins in Advanced Microelectronics Packaging,ADVANCED ENGINEERING MATERIALS, Issue 4 2004W. Zhang Novel crosslinking of high-order and multiple copper twins has been formed in the metallization/solder interconnect subjected to the thermal aging. This surprising finding may illustrate a universal metallization failure mode. Meanwhile, many copper nanocrystals in situ originated from those twins crosslinking shed a novel light on the synthesis approach to fascinating nanocrystalline metals. [source] A DC stabilized log-domain nth-order multifunction filter based on the decomposition of nth-order HP filter function to FLF topologyINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 10 2009N. A. Shah Abstract The design of high-order log-domain filters can be easily accomplished by transposing already known linear-domain Gm -C filter topologies to their counterparts in the log-domain through the employment of a set of complementary operators. To achieve the Gm -C filter topologies, the multiple feedback approach is widely used due to its accrued advantages. In this paper a synthesis approach for the development of an nth-order multifunction log-domain filter comprising lowpass (LP), highpass (HP) and bandpass (BP) filter functions is proposed. The approach is based on the decomposition of nth-order HP filter function to follow-the-leader-feedback (FLF) topology. The design is simple and simultaneously achieves nearly all of the chief advantages. The design offers superior performance factors vis-à-vis the ones recently reported. To verify the high-order behavior of the topology, a 5th-order multifunction filter was designed and the achieved simulated results verify the theory. Copyright © 2008 John Wiley & Sons, Ltd. [source] Synthesis of Fullerene-like Cs2O Nanoparticles by Concentrated Sunlight,ADVANCED MATERIALS, Issue 22 2006A. Albu-Yaron Application of a solar-driven synthesis approach for the production of fullerene-like Cs2O nanoparticles is presented (see figure). The synthesis is performed directly in evacuated quartz ampoules containing a Cs2O crystallite precursor under continuous irradiation with highly concentrated sunlight. Closed-cage nested Cs2O structures are obtained in a variety of shapes and dimensions. These structures are rather stable, a significant advantage for photoemissive applications involving Cs2O coatings. [source] A Chemical Approach Towards Understanding the Mechanism and Reversal of Drug Resistance in Plasmodium falciparum: Is it Viable?IUBMB LIFE, Issue 4-5 2002Kelly Chibale Abstract Genetic and biochemical approaches to studies of drug resistance mechanisms in Plasmodium falciparum have raised controversies and contradictions over the past several years. A different and novel chemical approach to this important problem is desirable at this point in time. Recently, the molecular basis of drug resistance in P. falciparum has been associated with mutations in the resistance genes, Chloroquine Resistance Transporter (PfCRT) and the P-glycoprotein homologue (Pgh1). Although not the determinant of chloroquine resistance in P. falciparum, mutations in Pgh1 have important implications for resistance to other antimalarial drugs. Because it is mutations in the aforementioned resistance genes rather than overexpression that has been associated with drug resistance in malaria, studies on mechanisms of drug resistance and its reversal by chemosensitisers should benefit from a chemical approach. Target-oriented organic synthesis of chemosensitisers against proteins implicated in drug resistance in malaria should shed light on mechanism of drug resistance and its reversal in this area. The effect of structurally diverse chemosensitisers should be examined on several putative resistance genes in P. falciparum to deal with antimalarial drug resistance in the broadest sense. Therefore, generating random mutations of these resistance proteins and subsequent screening in search of a specific phenotype followed by a search for mutations and/or chemosensitisers that affect a specific drug resistance pathway might be a viable strategy. This diversity-oriented organic synthesis approach should offer the means to simultaneously identify resistance proteins that can serve as targets for therapeutic intervention (therapeutic target validation) and chemosensitisers that modulate the functions of these proteins (chemical target validation). [source] Synthesis of ultrawideband bandpass filter by multisection of commensurate stepped-impedance resonatorsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2008Chun-Ping Chen Abstract A novel filter prototype composed of multisection of stepped impedance resonators (SIRs) is proposed to realize the ultra-wideband bandpass (UWB) filter. The relation between the modes number and stage number of resonators is first discussed, followed by the derivation of the corresponding Chebyshev filtering function. Furthermore, the equivalent circuit model of this new filter prototype is established based on the transmission-line theory for filter synthesis. As an example, a FCC UWB filter is synthesized with the proposed filter prototype to possess a passband from 3.1 to 10.6 GHz (fractional bandwidth is about 110%). The synthesized circuit model are further optimized by EM simulator, fabricated in microstrip line, and characterized by network analyzer. The good agreement between the measured and predicted frequency responses validates the effectiveness of newly proposed synthesis approach. In addition, the designed filter exhibits good characteristics of comparatively low insertion loss, quite sharp skirts, very flat group delay, and good stopband (especially in lower one) as well. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2635,2639, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23756 [source] Development and Applications of Topologically Segregated Bilayer Beads in One-bead One-compound Combinatorial LibrariesMOLECULAR INFORMATICS, Issue 10 2005Ruiwu Liu Abstract Using a "split,mix" synthesis approach, "One-Bead One-Compound" (OBOC) combinatorial libraries can be generated such that each bead displays only one chemical entity. Tens of thousands to millions of compound-beads can be screened concurrently using a variety of biochemical and cell-based screening methods. Positive beads are then physically isolated for structure determination. Peptide beads or peptoid beads consisting of ,-amino acids and with a free N -terminus can be routinely sequenced by an automatic microsequencer using Edman chemistry. Libraries with N -terminally blocked peptides, peptides with unsequenceable building blocks, or small molecules require encoding. To fully exploit the OBOC combinatorial library methods, we have developed topologically segregated bilayer beads. Such bilayer beads allow us to prepare library compound on the outer layer of each bead and the coding tags in the bead interior. In addition, we can use these bilayer beads to prepare OBOC combinatorial libraries that are down-substituted on the bead surface but fully substituted in the bead interior. This configuration enables one to screen at a much higher stringency and yet have enough peptides or coding tags retained in the bead interior for structure determination. [source] A systematic narrative review of the studies on structured child-centred interventions for families with a parent with cancerPSYCHO-ONCOLOGY, Issue 5 2010Mika Niemelä Abstract Objective: To perform a systematic narrative review of the current state of published articles on the structured interventions targeted at children with a parent suffering from cancer. Methods: The study was based on a narrative synthesis approach. Eleven structured child-centred intervention studies were systematically searched through PubMed, PsycINFO and MEDLINE. The interventions were grouped into two main categories: ,structured family interventions' and ,structured peer group interventions'. Special attention was focused on the preventive purpose of the interventions. Results: The participants (children, parents and health professionals) reported several positive impacts of interventions on children's and parents' psychosocial well-being, although no improvement or changes were also observed. The effect of interventions on the children was evaluated by structured methods only in five studies. Conclusions: This review showed the lack of valid psychosocial preventive intervention methods focusing on children with parental cancer and highlighted the need of intervention research with controlled study designs and long follow-up periods. However, an intervention method should be easy to train and applicable to the clinical practice of healthcare professionals. By refining the practice-based experiences with scientific research evidence it is possible to move to the next level in providing psychosocial support and prevention for children living in families with parental cancer. Copyright © 2009 John Wiley & Sons, Ltd. [source] An intermediate in a new synthesis approach to ,-substituted ,-hydroxyaspartameACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2003Johny Wehbe The crystal and molecular structure of 1- tert -butyl 4-ethyl (2,R,3,R,5,R,2S,3S)-3-bromomethyl-3-hydroxy-2-[(2,-hydroxy-2,,6,,6,-trimethylbicyclo[3.1.1]hept-3,-ylidene)amino]succinate, C21H34BrNO6, is presented. This compound is an intermediate in the new synthetic route to ,-substituted ,-hydroxyaspartates, which are blockers of glutamate transport. [source] Expression, purification, and analysis of unknown translation factors from Escherichia coli: A synthesis approachBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 1 2010Justin D. Walter Abstract New approaches are currently being developed to expose biochemistry and molecular biology undergraduates to a more interactive learning environment. Here, we propose a unique project-based laboratory module, which incorporates exposure to biophysical chemistry approaches to address problems in protein chemistry. Each of the experiments described herein contributes to the stepwise process of isolating, identifying, and analyzing a protein involved in a central biological process, prokaryotic translation. Students are provided with expression plasmids that harbor an unknown translation factor, and it is their charge to complete a series of experiments that will allow them to develop hypotheses for discovering the identity of their unknown (from a list of potential candidates). Subsequent to the identification of their unknown translation factor, a series of protein unfolding exercises are performed employing circular dichroism and fluorescence spectroscopies, allowing students to directly calculate thermodynamic parameters centered around determining the equilibrium constant for unfolding as a function of denaturant (temperature or chemical). The conclusion of this multi-part laboratory exercise consists of both oral and written presentations, emphasizing synthesis of the roles of each translation factor during the stepwise process of translation. [source] Diatomaceous Lessons in Nanotechnology and Advanced MaterialsADVANCED MATERIALS, Issue 29 2009Dusan Losic Abstract Silicon, in its various forms, finds widespread use in electronic, optical, and structural materials. Research on uses of silicon and silica has been intense for decades, raising the question of how much diversity is left for innovation with this element. Shape variation is particularly well examined. Here, we review the principles revealed by diatom frustules, the porous silica shells of diatoms, microscopic, unicellular algae. The frustules have nanometer-scale detail, and the almost 100,000 species with unique frustule morphologies suggest nuanced structural and optical functions well beyond the current ranges used in advanced materials. The unique frustule morphologies have arisen through tens of millions of years of evolutionary selection, and so are likely to reflect optimized design and function. Performing the structural and optical equivalent of data mining, and understanding and adopting these designs, affords a new paradigm in materials science, an alternative to combinatorial materials synthesis approaches in spurring the development of new material and more nuanced materials. [source] Comparison between models of insulator and semiconductor thin films islandingPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2007François Lallet Abstract The synthesis of self-organized quantum dots (QD's) can be achieved through bottom up layer by layer deposition processes as chemical vapor deposition (CVD) or physical vapor deposition (PVD). However, QD's may also be synthesized via sol-gel route, which involves a spontaneous evolution from thin films to discrete QD's without further deposition. The aim of the paper is to discuss and compare the physical phenomena involved in QD's formation which initiate from thin film surface roughening between PVDCVD and sol-gel synthesis approaches. We propose two simple physical models which are relevant to explain the fundamental differences between those methods. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Optimal Synthesis of Protein Purification ProcessesBIOTECHNOLOGY PROGRESS, Issue 4 2001Elsa Vásquez-Alvarez There has been an increasing interest in the development of systematic methods for the synthesis of purification steps for biotechnological products, which are often the most difficult and costly stages in a biochemical process. Chromatographic processes are extensively used in the purification of multicomponent biotechnological systems. One of the main challenges in the synthesis of purification processes is the appropriate selection and sequencing of chromatographic steps that are capable of producing the desired product at an acceptable cost and quality. This paper describes mathematical models and solution strategies based on mixed integer linear programming (MILP) for the synthesis of multistep purification processes. First, an optimization model is proposed that uses physicochemical data on a protein mixture, which contains the desired product, to select a sequence of operations with the minimum number of steps from a set of candidate chromatographic techniques that must achieve a specified purity level. Since several sequences that have the minimum number of steps may satisfy the purity level, it is possible to obtain the one that maximizes final purity. Then, a second model that may use the total number of steps obtained in the first model generates a solution with the maximum purity of the product. Whenever the sequence does not affect the final purity or more generally does not impact the objective function, alternative models that are of smaller size are developed for the optimal selection of steps. The models are tested in several examples, containing up to 13 contaminants and a set of 22 candidate high-resolution steps, generating sequences of six operations, and are compared to the current synthesis approaches. [source] Carbon Nanotube and Gold-Based Materials: A SymbiosisCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2010Rajpal Singh Dr. Abstract Carbon nanotubes constitute a novel class of nanomaterials with potential applications in many areas. The attachment of metal nanoparticles to carbon nanotubes is new way to obtain novel hybrid materials with interesting properties for various applications such as catalysts and gas sensors as well as electronic and magnetic devices. Their unique properties such as excellent electronic properties, a good chemical stability, and a large surface area make carbon nanotubes very useful as a support for gold nanoparticles in many potential applications, ranging from advanced catalytic systems through very sensitive electrochemical sensors and biosensors to highly efficient fuel cells. Here we give an overview on the recent progress in this area by exploring the various synthesis approaches and types of assemblies, in which nanotubes can be decorated with gold nanoparticles and explore the diverse applications of the resulting composites. [source] | |||||||||||||||||||