Its Application (its + application)

Distribution by Scientific Domains
Distribution within Chemistry


Selected Abstracts


Parallel Algorithms for Dynamic Shortest Path Problems

INTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 3 2002
Ismail Chabini
The development of intelligent transportation systems (ITS) and the resulting need for the solution of a variety of dynamic traffic network models and management problems require faster-than-real-time computation of shortest path problems in dynamic networks. Recently, a sequential algorithm was developed to compute shortest paths in discrete time dynamic networks from all nodes and all departure times to one destination node. The algorithm is known as algorithm DOT and has an optimal worst-case running-time complexity. This implies that no algorithm with a better worst-case computational complexity can be discovered. Consequently, in order to derive algorithms to solve all-to-one shortest path problems in dynamic networks, one would need to explore avenues other than the design of sequential solution algorithms only. The use of commercially-available high-performance computing platforms to develop parallel implementations of sequential algorithms is an example of such avenue. This paper reports on the design, implementation, and computational testing of parallel dynamic shortest path algorithms. We develop two shared-memory and two message-passing dynamic shortest path algorithm implementations, which are derived from algorithm DOT using the following parallelization strategies: decomposition by destination and decomposition by transportation network topology. The algorithms are coded using two types of parallel computing environments: a message-passing environment based on the parallel virtual machine (PVM) library and a multi-threading environment based on the SUN Microsystems Multi-Threads (MT) library. We also develop a time-based parallel version of algorithm DOT for the case of minimum time paths in FIFO networks, and a theoretical parallelization of algorithm DOT on an ,ideal' theoretical parallel machine. Performances of the implementations are analyzed and evaluated using large transportation networks, and two types of parallel computing platforms: a distributed network of Unix workstations and a SUN shared-memory machine containing eight processors. Satisfactory speed-ups in the running time of sequential algorithms are achieved, in particular for shared-memory machines. Numerical results indicate that shared-memory computers constitute the most appropriate type of parallel computing platforms for the computation of dynamic shortest paths for real-time ITS applications. [source]


Double Modification of Electrode Surface for the Selective Detection of Epinephrine and Its Application to Flow Injection Amperometric Analysis

ELECTROANALYSIS, Issue 22 2009
Guang-Ri Xu
Abstract A glassy carbon electrode having two polymer layers has been applied to selectively detect epinephrine. The inner layer formed by electropolymerization of macrocyclic nickel complex functioned as an electrocatalyst for epinephrine oxidation and the outer layer composed of hydrolyzed polyurethane ,-benzyl L -glutamate as a screening layer. Differential pulse voltammetry showed almost 100% recovery of epinephrine even in 100-fold excess of interferents. When applied to a dual glassy carbon electrode as an amperometric detector in flow injection analysis, a linear response over 0.1,,M and 10,,M was obtained. Recovery tested for 5-fold diluted human urine samples was 97.5%. [source]


The Fabrication and Characterization of a Bismuth Nanoparticle Modified Boron Doped Diamond Electrode and Its Application to the Simultaneous Determination of Cadmium(II) And Lead(II)

ELECTROANALYSIS, Issue 16 2008
Kathryn
Abstract We report the simultaneous electroanalytical determination of Pb2+ and Cd2+ by square-wave anodic stripping voltammetry (SWASV) using a bismuth nanoparticle modified boron doped diamond (Bi-BDD) electrode. Bi deposition was performed in situ with the analytes, from a solution of 0.1,mM Bi(NO3)3 in 0.1,M HClO4 (pH,1.2), and gave detection limits of 1.9,,g L,1 and 2.3,,g L,1 for Pb(II) and Cd(II) respectively. Pb2+ and Cd2+ could not be detected simultaneously at a bare BDD electrode, whilst on a bulk Bi macro electrode (BiBE) the limits of detection for the simultaneous determination of Pb2+ and Cd2+ were ca. ten times higher. [source]


Some Properties of Sodium Dodecyl Sulfate Functionalized Multiwalled Carbon Nanotubes Electrode and Its Application on Detection of Dopamine in the Presence of Ascorbic Acid

ELECTROANALYSIS, Issue 16 2008
Dan Zheng
Abstract A sodium dodecyl sulfate (SDS) functionalized multiwalled carbon nanotubes (MWNTs) electrode (SDS/MWNTs) was successfully constructed in this study. The electrochemical property of the SDS/MWNTs electrode has been characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Nyquist plots suggest that the immersion time of SDS affects the resistances of the MWNTs electrodes. The thickness of adsorbed SDS on MWNTs surface is estimated to be 1.23,nm, which is close to the value of SDS monolayer. CV results demonstrate a 5-fold enhanced response for dopamine (DA) at the SDS/MWNTs electrode compared to the bare MWNTs one. DPV results illustrate that DA can be selectively determined in the presence of high concentration ascorbic acid (AA) with a linear range from 20,,M to 0.20,mM and a sensitivity of 0.024,,A ,M,1 at the SDS/MWNTs electrode. [source]


Development of a Novel Automatic Potentiometric System for Determination of Selenium and Its Application in Pharmaceutical Formulations and Anodic Slime

ELECTROANALYSIS, Issue 9 2008
Ayman
Abstract Poly(vinyl chloride) polymeric membrane sensors containing Sn(IV) phthalocyanine dichloride (SnPC) and Co(II) phthalocyanine (CoPC) as novel electroactive materials dispersed in o -nitrophenyl octylether (o -NPOE) as a plasticizer are examined potentiometrically with respect to their response toward selenite (SeO32,) ions. Fast Nernstian response for SeO32, ions over the concentration ranges 7.0×10,6,1.0×10,3 and 8.0×10,6,1.0×10,3 mol L,l at pH,3.5,8.5 with lower detection limit of 5.0×10,6 and 8.0×10,6 mol L,1 and calibration slopes of ,25.4 and ,29.7,mV decade,1 are obtained with SnPC and CoPC based membrane sensors, respectively. The proposed sensors reveals by the modified separate solution method (MSSM) a good selectivity over different anions which differ significantly from the classical Hofmeister series. A segmented sandwich membrane method is used to determine complex formation constants of the ionophores in situe in the solvent polymeric sensing membranes. Membrane incorporating CoPC in a tubular flow detector is used in a two channels flow injection set up for continuous monitoring of selenite at a frequency of ca. 50 samples h,1. Direct determination of selenium in pharmaceutical formulations and anodic slime gives results in good agreement with data obtained using standard ICP method. [source]


Properties of Poly(sodium 4-styrenesulfonate)-Ionic Liquid Composite Film and Its Application in the Determination of Trace Metals Combined with Bismuth Film Electrode

ELECTROANALYSIS, Issue 5 2008
Jianbo Jia
Abstract A new kind of bismuth film modified electrode to sensitively detect trace metal ions based on incorporating highly conductive ionic liquids 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIMPF6) in solid matrices at glassy carbon (GC) was investigated. Poly(sodium 4-styrenesulfonate) (PSS), silica, and Nafion were selected as the solid matrices. The electrochemical properties of the mixed films modified GC were evaluated. The electron transfer rate of Fe(CN)64,/Fe(CN)63, can be effectively improved at the PSS-BMIMPF6 modified GC. The bismuth modified PSS-BMIMPF6 composite film electrodes (GC/PSS-BMIMPF6/BiFEs) displayed high mechanical stability and sensitive stripping voltammetric performances for the determination of trace metal cations. The GC/PSS-BMIMPF6/BiFE exhibited well linear response to both Cd(II) and Pb(II) over a concentration range from 1.0 to 50,,g L,1. And the detection limits were 0.07,,g L,1 for Cd(II) and 0.09,,g L,1 for Pb(II) based on three times the standard deviation of the baseline with a preconcentration time of 120,s, respectively. Finally, the GC/PSS-BMIMPF6/BiFEs were successfully applied to the determination of Cd(II) and Pb(II) in real sample, and the results of present method agreed well with those of atomic absorption spectroscopy. [source]


New Methylene Blue (NMB) Encapsulated in Mesoporous AlMCM-41 Material and Its Application for Amperometric Determination of Ascorbic Acid in Real Samples

ELECTROANALYSIS, Issue 15 2007
Shabnam Sohrabnezhad
Abstract New methylene blue (NMB) dye incorporated into AlMCM-41 surfactant-free and hybrid surfactant-AlMCM-41 mesophase. UV-vis evidence shows that new methylene blue dye protonated in both cases of zeolites. New methylene blue is electroactive in zeolites and their electrochemical activity has been studied by cyclic voltammetry and compared to that of NMB in aqueous solutions. New methylene blue molecules are not released to the solution during CV measurements and are accessible to H3O+ ions. The presence of surfactant affects the kinetics of the redox process through proton ions diffusion. The midpoint potentials (Em) values show that new methylene blue dye incorporated into AlMCM-41 can be reduced easily with respect to solution new methylene blue. New methylene blue interacting with surfactant polar heads and residual Br, ions as a results, it shows a couple of peaks in high potential with respect to new methylene blue solution. The electrode made with methylene blue-AlMCM-41 without surfactant was used for the mediated oxidation of ascorbic acid. The anodic peak current observed in cyclic voltammetry was linearly dependent on the ascorbic acid concentration. The calibration plot was linear over the ascorbic acid concentration range 1.0×10,5 to 5.0×10,4 M. The detection limit of the method is 1.0×10,5 M, low enough for trace ascorbic acid determination in various real samples. [source]


Photoelectro-Synergistic Catalysis at Ti/TiO2/PbO2 Electrode and Its Application on Determination of Chemical Oxygen Demand

ELECTROANALYSIS, Issue 22 2006
Jiaqing Li
Abstract In this paper, photoelectro-synergistic catalysis oxidation of organics in water on Ti/TiO2/PbO2 electrode was investigated by the method of electrochemistry. Furthermore, the results were compared with those obtained from photocatalysis and electrocatalysis. The method proposed was applied to determine the chemical oxygen demand (COD) value, Ti/TiO2/PbO2 electrode functioning as the work electrode during the process. It was shown that the method of photoelectro-synergistic catalysis had lower detection limit and wider linear range than the methods of electroassisted photocatalysis and electrocatalysis. The results obtained by the proposed method and conventional one were compared by carrying out the experiment on 8 wastewater samples. The correlation of the results using different methods was satisfactory and the relative bias was below ±6.0%. [source]


Sol-Gel Entrapped Pyridinium Hydrobromide Perbromide as a Recyclable Bromination Agent: Its Application to a One-Pot Bromination and Dehydrobromination Process

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2006
Yevgenia Levin
Abstract Silica sol-gel encaged pyridinium hydrobromide perbromide can be used for clean, odorless bromination of a variety of substrates, including alkenes, ketones, and arenes. The used heterogenized bromination reagent can be recharged with bromine and recycled. In the presence of sol-gel entrapped 1,5,7-triazabicyclo[4.4.0]dec-5-ene, dibromides are dehydrobrominated to give vinyl monobromides and/or alkynes. Encapsulation of the pyridinium derivative and the guanidine base within separate sol-gel matrices enables the use of both opposing reagents in one-pot reactions without their mutual destroying each other. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


Lithiation of 2-Aryl-2-(chloroaryl)-1,3-dioxolanes and Its Application in the Synthesis of New ortho -Functionalized Benzophenone Derivatives

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2004
Gyula Lukács
Abstract 2-Aryl-2-(chloroaryl)-1,3-dioxolanes 4 were lithiated ortho to the ketal group of the chloroaryl ring by treatment with butyllithium in THF between ,78 and 0 °C. The site selectivity of some of the deprotonation reactions was rationalized by the long-range effect of the 4-chloro substituent. The lithio species thus generated were treated with various electrophiles to give ortho -functionalized benzophenone derivatives. Intramolecular competition between the aryl rings was observed in the lithiation of 2-(4-chlorophenyl)-2-(4-fluorophenyl)-1,3-dioxolane (4s). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


Umpolung of the 5-Alkyl-2-dimethylamino-1,3-dithiolium-4-thiolate Mesoion and Its Application in the Synthesis of Some New Tetrathiafulvalenes

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2004
Jonas Hellberg
Abstract The 5-alkyl-2-dimethylamino-1,3-dithiolium-4-thiolate mesoion could be umpoled with sulfuryl chloride to yield a dicationic electrophile 3 that reacted with various electron-rich aromatic substrates to yield arylthio-substituted 1,3-dithiolium salts 13,25. Two of these compounds have been transformed to the corresponding symmetrical tetrathiafulvalenes 43 and 44, and their cyclovoltammetric behaviour recorded. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


Fast High-Temperature Response of Carbon Nanotube Film and Its Application as an Incandescent Display

ADVANCED MATERIALS, Issue 35 2009
Peng Liu
Super aligned carbon nanotube (CNT) film shows a fast high-temperature response: the film can be heated to incandescence and cools down in about 1 ms. Using screen printing and laser cutting, an incandescent CNT film array that can dynamically display Chinese characters is fabricated. More applications of the film may be developed based on its fast response. [source]


A Novel Thermally Stable Spironaphthoxazine and Its Application in Rewritable High Density Optical Data Storage,

ADVANCED MATERIALS, Issue 2 2005
W. Yuan
A novel spironaphthoxazine SOFC molecule with a stable ring-opened photomerocyanine form by incorporating a ferrocene moiety to the parent spironaphthoxazine has been synthesized. Two-dimensional luminescence images obtained by confocal microscope employing fluorescence as read-out method (see Figure) and three-dimensional high-density recording using two-photon technology of SOFC-poly(methyl methacrylate) films are demonstrated. [source]


Development of a New Spiro-BOX Ligand and Its Application in Highly Enantioselective Palladium-Catalyzed Cyclization of 2-Iodoanilines with Allenes

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009
Wei Shu
Abstract In this communication, we report the synthesis of a new chiral spiro-bisoxazoline ligand, i.e., ,-naphthylmethyl-substituted spiro-BOX [(Ra,S,S)- L7] and have successfully applied it to the palladium-catalyzed enantioselective cyclization reaction of simple allenes with o -aminoiodobenzenes, affording highly optically active 3-alkylideneindolines in good yields with excellent enantiomeric excesses. [source]


Maximum Daily 6 Minutes of Activity: An Index of Functional Capacity Derived from Actigraphy and Its Application to Older Adults with Heart Failure

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2010
Jason Howell BA
OBJECTIVES: To compare the correlation between the maximum 6 minutes of daily activity (M6min) and standard measures of functional capacity in older adults with heart failure (HF) with that in younger subjects and its prognostic utility. DESIGN: Prospective, cohort study. SETTING: Tertiary care, academic HF center. PARTICIPANTS: Sixty, ambulatory, adults, New York Heart Association (NYHA) Class I to III, stratified into young (50.9 ± 9.4) and older cohorts (76.8 ± 8.0). MEASUREMENTS: Correlation between M6min and measures of functional capacity (6-minute walk test; 6MWT) and peak oxygen consumption (VO2) according to cardiopulmonary exercise testing in a subset of subjects. Survival analysis was employed to evaluate the association between M6min and adverse events. RESULTS: Adherence to actigraphy was high (90%) and did not differ according to age. The correlation between M6min and 6MWT was higher in subjects aged 65 and older than in those younger than 65 (correlation coefficient (r=0.702, P<.001 vs r=0.490, P=.002). M6min was also significantly associated with peak VO2 (r=0.612, P=.006). During the study, 26 events occurred (2 deaths, 10 hospitalizations, 8 emergency department visits, and 6 intercurrent illnesses). The M6min was significantly associated with subsequent events (hazard ratio=2.728, 95% confidence interval=1.10,6.77, P=.03), independent of age, sex, ejection fraction, NYHA class, brain natriuretic peptide, and 6MWT. CONCLUSION: The high adherence to actigraphy and association with standard measures of functional capacity and independent association with subsequent morbid events suggest that it may be useful for monitoring older adults with HF. [source]


Message Effects and Social Determinants of Health: Its Application to Cancer Disparities

JOURNAL OF COMMUNICATION, Issue 2006
K. Viswanath
Recent work on message effects theories offers a fruitful way to systematically explore how features, formats, structures of messages may attract audience attention and influence the audience and is of great relevance to public health communications. Much of this work, however, has been pursued primarily at the individual level of analysis. It is our contention that message effects on health outcomes could potentially be moderated and mediated by social contextual factors in public health such as social class, social organizations and neighborhoods among others, leading to differential effects among different audience sub-groups. This essay, through a selective review of literatures in communication and social epidemiology, will explore how major message effects may moderate and mediate the role of social determinants of health on cancer control, specifically cancer-related health disparities. [source]


A New Immune Genetic Algorithm and Its Application in Redundant Manipulator Path Planning

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 3 2004
Xiaoping Luo
In this paper, first the immune system is analyzed in a relatively deeper and all-sided point of view reflecting the fresh research in biology. Second, based on the previous statements, a new optimization method, the immune genetic algorithm (IGA), is presented by simulating the behavior of the biological immune system and is proved to converge to the global optimum with probability 1. Third, a new method on the multi-object optimization that is transformed into a single-object one is proposed based on the joints' best compliance in the redundant robot path planning using IGA. Last, the experiment results show that the method of this article behaves more successfully. © 2004 Wiley Periodicals, Inc. [source]


Physical Properties of Gelidium corneum,Gelatin Blend Films Containing Grapefruit Seed Extract or Green Tea Extract and Its Application in the Packaging of Pork Loins

JOURNAL OF FOOD SCIENCE, Issue 1 2009
Y.-H. Hong
ABSTRACT:, Edible Gelidium corneum,gelatin (GCG) blend films containing grapefruit seed extract (GFSE) or green tea extract (GTE) were manufactured, and the quality of pork loins packed with the film during storage was determined. Tensile strength (TS) and water vapor permeability (WVP) of the films containing GFSE or GTE were better than those of the control. The film's antimicrobial activity against Escherichia coli O157:H7 and Listeria monocytogenes increased with increasing antimicrobial concentration, resulting in a decrease in the populations of bacteria by 0.77 to 2.08 and 0.91 to 3.30 log CFU/g, respectively. Pork loin samples were inoculated with E. coli O157:H7 and L. monocytogenes. The samples packed with the GCG film containing GFSE (0.08%) or GTE (2.80%) had a decrease in the populations of E. coli O157:H7 and L. monocytogenes of 0.69 to 1.11 and 1.05 to 1.14 log CFU/g, respectively, compared to the control after 4 d of storage. The results showed that the quality of pork loins during storage could be improved by packaging them with the GCG film containing GFSE or GTE. [source]


Hairy Root and Its Application in Plant Genetic Engineering

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 2 2006
Zhi-Bi Hu
Abstract Agrobacterium rhizogenes Conn. causes hairy root disease in plants. Hairy root-infected A. rhizogenes is characterized by a high growth rate and genetic stability. Hairy root cultures have been proven to be an efficient means of producing secondary metabolites that are normally biosynthesized in roots of differentiated plants. Furthermore, a transgenic root system offers tremendous potential for introducing additional genes along with the Ri plasmid, especially with modified genes, into medicinal plant cells with A. rhizogenes vector systems. The cultures have turned out to be a valuable tool with which to study the biochemical properties and the gene expression profile of metabolic pathways. Moreover, the cultures can be used to elucidate the intermediates and key enzymes involved in the biosynthesis of secondary metabolites. The present article discusses various applications of hairy root cultures in plant genetic engineering and potential problems associated with them. (Managing editor: Wei Wang) [source]


Quality of Life: Its Application to Persons With Intellectual Disabilities and Their Families,Introduction and Overview

JOURNAL OF POLICY AND PRACTICE IN INTELLECTUAL DISABILITIES, Issue 1 2009
Roy I. Brown
Abstract The authors provide an overview of quality of life (QoL) conceptualization in the field of intellectual disabilities (ID), provide background information, and set an organizing framework for presenting concepts and concrete ideas for applying QoL. This framework is useful for three broad categories of application in the field of ID that form the application of QoL to individuals, groups of individuals, and to families. QoL thus can be used as a sensitizing notion that gives a sense of reference and guidance from the individual's perspective, focusing on the person and the individual's environment and provides a framework for conceptualizing, measuring, and applying the QoL construct. The applications also frame evaluation strategies for QoL research. The authors conclude that there is a need to identify relevant QoL evidence from the literature in a proactive way, and to ensure that it is methodologically sound, provides both quantitative and qualitative data, represents inter- and intra-individual variability, and illustrates changes over both the lifespan and across cultural settings. [source]


Topological Electronegativity Index and Its Application , I. Ionization Potentials of Alkyl Groups and Alkyl Halides

MOLECULAR INFORMATICS, Issue 9 2007
Chenzhong Cao
Abstract A Topological Electronegativity Index (TEI) for alkyl group was developed, based on the bond adjacency matrix of the radical atom. Taking the radical atom and the adjacency atoms (or groups) as the vertices of molecular graph of the alkyl group, the bond adjacency matrix was constructed, in which the diagonal elements were assigned the Pauling electronegativity of the atom (or group), and the off-diagonal elements were assigned values 1 or 0. The off-diagonal elements represent the bond connections: that is when the two atoms (or groups) connect with each other, it is 1; otherwise is 0. From the matrix, the eigenvalues were obtained and its geometric mean value was considered as the TEI of an alkyl. The calculated TEI has good correlation with its experimental ionization potential. Further, the TEI was applied to correlate with the ionization potentials of alkyl halides and substituted ethenes, and to correlate with the Bond Dissociation Energies (BDEs) of the CiH bonds in alkanes. [source]


DFT Based Atomic Softness and Its Application in Site Selectivity

MOLECULAR INFORMATICS, Issue 8 2003
P. Singh
Abstract Active site of a complex molecule and mechanism of chemical reaction has been studied with the help of atomic softness values derived from calculation based on Density functional theory. The quantum mechanical equation of Klopman has been solved with the help of AM1 calculation by using Win MOPAC7.21 software. On the basis of chemical potential equalization principle, and Koopmans theorem for frontier orbitals a formalism has been developed for the calculation of electron affinity of an atom in a molecule EA. The reliability of the EA values have been tested with electron density (obtained from AM1 calculation) and Fukui function values taken from literature. [source]


Nonimmersive Virtual Reality Mirror Visual Feedback Therapy and Its Application for the Treatment of Complex Regional Pain Syndrome: An Open-Label Pilot Study

PAIN MEDICINE, Issue 4 2010
Kenji Sato MD
Abstract Objective., Chronic pain conditions such as phantom limb pain and complex regional pain syndrome are difficult to treat, and traditional pharmacological treatment and invasive neural block are not always effective. Plasticity in the central nervous system occurs in these conditions and may be associated with pain. Mirror visual feedback therapy aims to restore normal cortical organization and is applied in the treatment of chronic pain conditions. However, not all patients benefit from this treatment. Virtual reality technology is increasingly attracting attention for medical application, including as an analgesic modality. An advanced mirror visual feedback system with virtual reality technology may have increased analgesic efficacy and benefit a wider patient population. In this preliminary work, we developed a virtual reality mirror visual feedback system and applied it to the treatment of complex regional pain syndrome. Design., A small open-label case series. Five patients with complex regional pain syndrome received virtual reality mirror visual feedback therapy once a week for five to eight sessions on an outpatient basis. Patients were monitored for continued medication use and pain intensity. Results., Four of the five patients showed >50% reduction in pain intensity. Two of these patients ended their visits to our pain clinic after five sessions. Conclusion., Our results indicate that virtual reality mirror visual feedback therapy is a promising alternative treatment for complex regional pain syndrome. Further studies are necessary before concluding that analgesia provided from virtual reality mirror visual feedback therapy is the result of reversing maladaptive changes in pain perception. [source]


C-Reactive Protein: A Guideline for Its Application

PREVENTIVE CARDIOLOGY, Issue 2 2003
Ezra A. Amsterdam MD Editor in Chief
No abstract is available for this article. [source]


Reaction of 2-(2,2,2-Trifluoroethylidene)-1,3-dithiane 1-Oxide with Ketones under Pummerer Conditions and Its Application to the Synthesis of 3-Trifluoromethyl-Substituted Five-Membered Heteroarenes,

ANGEWANDTE CHEMIE, Issue 13 2010
Takayuki Kobatake
Kinderleicht: Triflatanhydrid ermöglichte die Titelreaktion, die aus dem nucleophilen Angriff des Carbonylsauerstoffatoms auf das aktivierte kationische Schwefelzentrum und einer [3,3]-sigmatropen Umlagerung besteht (siehe Schema). Die Produkte sind Vorstufen für die schwierig herzustellenden fünfgliedrigen 3-Trifluormethylheteroarene. [source]


A Polybenzo[1,2- b:4,5- b,]dithiophene Derivative with Deep HOMO Level and Its Application in High-Performance Polymer Solar Cells,

ANGEWANDTE CHEMIE, Issue 8 2010
Lijun Huo Dr.
Sonnenanbeter: Das neue Polymer PBDTTBT erreicht Leistungsumwandlungseffizienzen bis 5.66,%. Die hohe Leerlaufspannung (0.92,V) ergibt sich aus der niedrigen HOMO-Energie des Polymers und hohen internen (IQE) wie externen Quanteneffizienzen (EQE) in einem großen Spektralbereich. PBDTTBT ist ein vielversprechendes Donormaterial für Polymersolarzellen. [source]


The Mean of the Inverse of a Punctured Normal Distribution and Its Application

BIOMETRICAL JOURNAL, Issue 4 2004
C. D. Lai
Abstract The fundamental properties of a punctured normal distribution are studied. The results are applied to three issues concerning X/Y where X and Y are independent normal random variables with means ,X and ,Y respectively. First, estimation of ,X/,Y as a surrogate for E(X/Y) is justified, then the reason for preference of a weighted average, over an arithmetic average, as an estimator of ,X/,Y is given. Finally, an approximate confidence interval for ,X/,Y is provided. A grain yield data set is used to illustrate the results. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Variable Selection for Model-Based High-Dimensional Clustering and Its Application to Microarray Data

BIOMETRICS, Issue 2 2008
Sijian Wang
Summary Variable selection in high-dimensional clustering analysis is an important yet challenging problem. In this article, we propose two methods that simultaneously separate data points into similar clusters and select informative variables that contribute to the clustering. Our methods are in the framework of penalized model-based clustering. Unlike the classical L1 -norm penalization, the penalty terms that we propose make use of the fact that parameters belonging to one variable should be treated as a natural "group." Numerical results indicate that the two new methods tend to remove noninformative variables more effectively and provide better clustering results than the L1 -norm approach. [source]


Production of a Desulfurization Biocatalyst by Two-Stage Fermentation and Its Application for the Treatment of Model and Diesel Oils

BIOTECHNOLOGY PROGRESS, Issue 5 2001
Je Hwan Chang
For the production of oil-desulfurizing biocatalyst, a two-stage fermentation strategy was adopted, in which the cell growth stage and desulfurization activity induction stage were separated. Sucrose was found to be the optimal carbon source for the growth of GordonianitidaCYKS1. Magnesium sulfate was selected to be the sulfur source in the cell growth stage. The optimal ranges of sucrose and magnesium sulfate were 10,50 and 1,2.5 g L,1, respectively. Such a broad optimal concentration of sucrose made the fed-batch culture easy, while the sucrose concentration was maintained between 10,20 g L,1 in the actual operation. As a result, 92.6 g L,1 of cell mass was acquired by 120 h of fed-batch culture. This cell mass was over three times higher than a previously reported result, though the strain used was different. The desulfurization activity of the harvested cells from the first stage culture was induced by batch cultivation with dibenzothiophene as the sole sulfur source. The optimal induction time was found to be about 4 h. The resting-cell biocatalyst made from the induced cells was applied for the deep desulfurization of a diesel oil. It was observed that the sulfur content of the diesel oil decreased from 250 mg-sulfur L-oil,1 to as low as 61 mg-sulfur L-oil,1 in 20 h. It implied that the biocatalyst developed in this study had a good potential to be applied to a deep desulfurization process to produce ultra-low-sulfur fuel oils. [source]


CO2 Density-Raman Shift Relation Derived from Synthetic Inclusions in Fused Silica Capillaries and Its Application

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2009
Yucai SONG
Abstract: The densities of CO2 inclusions in minerals are commonly used to determine the crystallizing conditions of the host minerals. However, conventional microthermometry is difficult to apply for inclusions of small size (< 5,10 ,m) or low density. Raman analysis is an alternative method for determining CO2 density, provided that the CO2 density,Raman shift relation is known. This study aims to establish this CO2 density,Raman shift relation by using CO2 inclusions synthesized in fused silica capillaries. By using this newly-developed synthetic technique, we formed pure CO2 inclusions, and their densities were determined by microthermometry. The Raman analysis showed that the relation between CO2 density (D in g/cm3) and the separations (? in cm,1) between the two main bands (i.e. Fermi diad bands) in CO2 Raman spectra can be represented by a cubic equation: D (g/cm3)=0.74203(,0.019?3+5.90332?2,610.79472?+21050.30165),3.54278 (r2=0.99920). Our calculated D value for a given ? is between those obtained from two previously-reported equations, which were derived from different experimental methods. An example was given in this study to demonstrate that the densities of natural CO2 inclusions that could not be derived from microthermometry could be determined by using our method. [source]