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Various Analytical Techniques (various + analytical_techniques)
Selected AbstractsTHE NEW INSTITUTIONAL ECONOMICS , A DIFFERENT APPROACH TO ECONOMIC ANALYSISECONOMIC AFFAIRS, Issue 3 2008Eirik G. Furubotn The initial objective of the paper is to describe the way in which the term ,New Institutional Economics' (NIE) emerged in the literature and became the designation for a new field concerned with the study of various analytical techniques designed for the exploration of institutional phenomena. It is then shown how some of the more important of these techniques, transaction-cost economics, property-rights analysis and contract theory, have been applied in two central lines of neoinstitutional thought , the Williamsonian and the Northian. Criticisms of these two disparate theoretical positions on the NIE are considered and assessed. Next, a brief review of some of the empirical literature is undertaken so that the explanatory powers of NIE themes can be gauged. Finally, the paper offers a few general remarks on the present state of the NIE and its possible influence on the further development of economics. [source] Identification of forty-five novel and twenty-three known NF1 mutations in Chinese patients with neurofibromatosis type 1,,HUMAN MUTATION, Issue 8 2006Ming-Jen Lee Abstract Neurofibromatosis type 1 (NF1), characterized by skin neurofibromas and an excess of café-au-lait spots, is due to mutations in the neurofibromin (NF1) gene. Identifying the genetic defect in individuals with the disease represents a significant challenge because the gene is extremely large with a high incidence of sporadic mutations across the entire gene ranging from single nucleotide substitutes to large deletions. In the present study, we have used a combination of techniques (heteroduplex analysis, sequencing, loss of heterozygosity and quantification of gene dosage) to define the genetic defect in 68 individuals from a cohort of 107 NF1 Taiwanese patients of Chinese origin. Fifty-eight were initially identified using heteroduplex analytical techniques and confirmed by sequence analysis. A further five were identified by direct sequence analysis alone. The reminders were shown to carry large deletions in the NF1 gene by demonstrating loss of heterozygosity that was confirmed by gene dosage measurements using quantitative-PCR techniques. Mis-sense, non-sense, frame-shift or splice-site mutations were identified across the entire gene of which the majority (45/68) were novel in nature. The detection rate with the various analytical techniques and the types of mutation detected are consistent with published data involving both individuals and large cohort studies from other ethnic backgrounds. © 2006 Wiley-Liss, Inc. [source] Pharmacokinetic aspects of biotechnology productsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2004Lisa Tang Abstract In recent years, biotechnologically derived peptide and protein-based drugs have developed into mainstream therapeutic agents. Peptide and protein drugs now constitute a substantial portion of the compounds under preclinical and clinical development in the global pharmaceutical industry. Pharmacokinetic and exposure/response evaluations for peptide and protein therapeutics are frequently complicated by their similarity to endogenous peptides and proteins as well as protein nutrients. The first challenge frequently comes from a lack of sophistication in various analytical techniques for the quantification of peptide and protein drugs in biological matrices. However, advancements in bioassays and immunoassays,along with a newer generation of mass spectrometry-based techniques,can often provide capabilities for both efficient and reliable detection. Selection of the most appropriate route of administration for biotech drugs requires comprehensive knowledge of their absorption characteristics beyond physicochemical properties, including chemical and metabolic stability at the absorption site, immunoreactivity, passage through biomembranes, and active uptake and exsorption processes. Various distribution properties dictate whether peptide and protein therapeutics can reach optimum target site exposure to exert the intended pharmacological response. This poses a potential problem, especially for large protein drugs, with their typically limited distribution space. Binding phenomena and receptor-mediated cellular uptake may further complicate this issue. Elimination processes,a critical determinant for the drug's systemic exposure,may follow a combination of numerous pathways, including renal and hepatic metabolism routes as well as generalized proteolysis and receptor-mediated endocytosis. Pharmacokinetic/pharmacodynamic (PK/PD) correlations for peptide and protein-based drugs are frequently convoluted by their close interaction with endogenous substances and physiologic regulatory feedback mechanisms. Extensive use of pharmacokinetic and exposure/response concepts in all phases of drug development has in the past been identified as a crucial factor for the success of a scientifically driven, evidence-based, and thus accelerated drug development process. Thus, PK/PD concepts are likely to continue and expand their role as a fundamental factor in the successful development of biotechnologically derived drug products in the future. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:2184,2204, 2004 [source] Recent trends in the total characterization of new-generation base fluidsLUBRICATION SCIENCE, Issue 2 2001I. D. Singh Abstract The quality of lubricating base oils used worldwide is changing rapidly as a result of stringent environmental regulation and the pressing need for oils to perform well under severe operating conditions. For example, although the base oil market in India now depends entirely on conventional group I base oils, group II and III base oils will soon be mandatory in lubrication formulation. These oils are generally more stable towards oxidation due to the virtual absence of heteroatom-containing compounds and to their low aromatic content. The analytical procedures developed over the years for the characterization of new and used group I mineral base oils will not be successful for all the requirements of these new oils. Thus, a systematic study is required to test the universal validity of characterisation methodology for these new-generation base fluids. This paper focuses on the use of various analytical techniques for base oil characterization and the methodology required for the total characterization of new-generation base oils. [source] Synthesis and Rheological Properties of Polylactide/Poly(ethylene glycol) Multiblock CopolymersMACROMOLECULAR BIOSCIENCE, Issue 11 2005Feng Li Abstract Summary: Ring-opening polymerization of D,L -lactide was carried out in the presence of poly(ethylene glycol), using Zn powder as catalyst. The hydroxyl-capped PLA-PEG-PLA triblock copolymers were coupled with adipoyl chloride at different molar ratios under mild conditions. N -Dimethylaminopyridine (DMAP) was used as catalyst of the coupling reaction. The resulting PLA/PEG multiblock copolymers were characterized by various analytical techniques such as IR, 1H NMR, SEC, and DSC. Sol-gel transition properties of the multiblock copolymers were investigated by mechanical rheology. The data showed that the sol-gel transition temperature and the transition modulus increased with increasing molecular weight and the solution concentration of the multiblock copolymers. Variation of storage modulus (G,) and loss modulus (G,) as a function of temperature for a 20% sample of MB3. [source] Molecular aspects on the interaction of protoberberine, benzophenanthridine, and aristolochia group of alkaloids with nucleic acid structures and biological perspectivesMEDICINAL RESEARCH REVIEWS, Issue 5 2007Motilal Maiti Abstract Alkaloids occupy an important position in chemistry and pharmacology. Among the various alkaloids, berberine and coralyne of the protoberberine group, sanguinarine of the benzophenanthridine group, and aristololactam-,- d -glucoside of the aristolochia group have potential to form molecular complexes with nucleic acid structures and have attracted recent attention for their prospective clinical and pharmacological utility. This review highlights (i) the physicochemical properties of these alkaloids under various environmental conditions, (ii) the structure and functional aspects of various forms of deoxyribonucleic acid (DNA) (B-form, Z-form, HL -form, protonated form, and triple helical form) and ribonucleic acid (RNA) (A-form, protonated form, and triple helical form), and (iii) the interaction of these alkaloids with various polymorphic DNA and RNA structures reported by several research groups employing various analytical techniques like absorbance, fluorescence, circular dichroism, and NMR spectroscopy; electrospray ionization mass spectrometry, thermal melting, viscosity, and DNase footprinting as well as molecular modeling and thermodynamic studies to provide detailed binding mechanism at the molecular level for structure,activity relationship. Nucleic acids binding properties of these alkaloids are interpreted in relation to their biological activity. © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 5, 649,695, 2007 [source] Synthesis of poly(aryl ether ketone)s containing diphenyl moieties by electrophilic Friedel,Crafts solution polycondensationPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 12 2009Mingzhong Cai Abstract A new monomer, 4,4,-bis(4-phenoxybenzoyl)diphenyl (BPOBDP), was prepared by Friedel,Crafts reaction of 4-bromobenzoyl chloride and diphenyl, followed by condensation with potassium phenoxide. Novel poly(ether ketone ketone) (PEKK)/poly(ether ketone diphenyl ketone ether ketone ketone) (PEKDKEKK) copolymers were synthesized by electrophilic Friedel,Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of diphenyl ether (DPE) and BPOBDP, in the presence of anhydrous aluminum chloride and N -methyl-pyrrolidone (NMP) in 1,2-dichloroethane (DCE). The copolymers obtained were characterized by various analytical techniques such as FT-IR, DSC, TGA, and wide-angle X-ray diffraction (WAXD). The results showed that the resulting copolymers exhibited excellent thermal stability due to the existence of diphenyl moieties in the main chain. The glass transition temperatures are above 152°C, the melting temperatures are above 276°C, and the temperatures at a 5% weight loss are above 548°C in nitrogen. The copolymers with 50,70,mol% BPOBDP had tensile strengths of 101.5,102.7,MPa, Young's moduli of 3.23,3.41,GPa, and elongations at break of 12,17%. All these copolymers were semicrystalline and insoluble in organic solvents. Copyright © 2008 John Wiley & Sons, Ltd. [source] Data analytics and stochastic modeling in a semiconductor fabAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 1 2010Sugato Bagchi Abstract The scale, scope and complexity of the manufacturing operations in a semiconductor fab lead to some unique challenges in ensuring product quality and production efficiency. We describe the use of various analytical techniques, based on data mining, process trace data analysis, stochastic simulation and production optimization, to address these manufacturing issues, motivated by the following two objectives. The first objective is to identify the sub-optimal process conditions or tool settings that potentially affect the process performance and product quality. The second objective is to improve the overall production efficiency through better planning and resource scheduling, in an environment where the product mix and process flow requirements are complex and constantly changing. Copyright © 2010 John Wiley & Sons, Ltd. [source] Tin(II) Doped Anatase (TiO2) Nanoparticles: A Potential Route to "Greener" Yellow PigmentsCHEMISTRY - AN ASIAN JOURNAL, Issue 6 2009Moumita Ghosh Dr. Abstract Benign by design: Tin(II) doped anatase TiO2 nanoparticles, a potential candidate as environmentally benign yellow pigments, have been synthesized. The presence of Sn2+ in anatase structure has been confirmed by various analytical techniques including optical and 119Sn Mössbauer spectroscopy. During our exploration of compounds in the SnII -TiIV -O system, we discovered that hydrolysis of titanium alkoxide solution in the presence of SnII salts resulted in stable deep-yellow colored anatase nanoparticles. The samples were characterized by X-ray powder diffraction, electron microprobe, thermal analysis, transmission electron microscopy, and 119Sn Mössbauer spectroscopy. Mössbauer data of the yellow colored samples showed the presence of both SnII and SnIV in a distorted environment as expected in the anatase structure. It is suggested that the cationic charge imbalance is compensated by oxygen vacancies and/or hydroxyl groups as evidenced by Mössbauer data which show two types of SnII environments. When heated in air to 300,°C the samples changed color to completely white and 119Sn Mössbauer data of these samples showed only the presence of SnIV. These observations indicate that the origin of the yellow color in our Sn doped anatase nanoparticles arises from filled Sn 5s states just above the O 2p band, thus decreasing the band gap. The SnII doped anatase TiO2 nanoparticles reported here can potentially lead to environmentally benign yellow pigments. The simplistic nature of the synthetic procedure could easily be adapted to large-scale industrial manufacture. [source] | |||||||||||||