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101.
Adams N De Gans BJ Kozodaev D Sanchez C Bastiaansen CW Broer DJ Schubert US 《Journal of combinatorial chemistry》2006,8(2):184-191
A methodology for the rapid design, screening, and optimization of coating systems with surface relief structures, using a combination of statistical experimental design, high-throughput experimentation, data mining, and graphical and mathematical optimization routines was developed. The methodology was applied to photopolymers used in photoembossing applications. A library of 72 films was prepared by dispensing a given amount of sample onto a chemically patterned substrate consisting of hydrophilic areas separated by fluorinated hydrophobic barriers. Film composition and film processing conditions were determined using statistical experimental design. The surface topology of the films was characterized by automated AFM. Subsequently, models explaining the dependence of surface topologies on sample composition and processing parameters were developed and used for screening a virtual 4000-membered in silico library of photopolymer lacquers. Simple graphical optimization or Pareto algorithms were subsequently used to find an ensemble of formulations, which were optimal with respect to a predefined set of properties, such as aspect ratio and shape of the relief structures. 相似文献
102.
This paper reports the successful design of a prototype of an optical biochemical sensor for the determination of hydroperoxides
in nonpolar organic liquids. The sensor consists of a matrix of an amphiphilic polymer conetwork (APCN), a novel class of
very promising polymeric materials for easy preparation of biochemical sensor matrices. APCNs are characterised by nanoscopic
phase separation between the hydrophilic and the hydrophobic phases. For medium ratios of conetwork composition, the domains
of both phases are interconnected both on the surface of the conetworks and throughout the bulk. The APCNs have peculiar swelling
properties—the hydrophilic phase swells in hydrophilic media and the hydrophobic phase swells in hydrophobic media. In both
types of media dissolved reagents can diffuse from the solution into the swollen phase of the polymeric conetwork. This enables
loading of the hydrophilic phase of the APCNs with enzymes and indicator reagents by simple impregnation. Hydrophobic analytes
can diffuse into the polymeric conetwork via its hydrophobic phase and react with indicator reagents immobilised in the hydrophilic
phase at the huge internal interface between the two opposite phases.
To prepare the described hydroperoxide-sensitive biosensors, we used APCN films consisting of 58% (w/w) poly(2-hydroxyethyl acrylate) (PHEA) as hydrophilic chains and 42% (w/w) polydimethylsiloxane (PDMS) as hydrophobic linkers. Horseradish peroxidase (HRP) and diammonium 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate)
(ABTS) as indicator reagent were co-immobilised in this optically clear and transparent matrix. In this feasibility study
the conditions investigated were principally those relevant to characterisation of the innovative matrix material and the
disposable biosensor produced from it; the biosensor was not optimised. Sensitivity toward tert-butylhydroperoxide (tBuOOH) dissolved in n-heptane was acceptable, between approximately 1 and at least 50 mmol L−1, even in the dry state. The response time was 1.7 to 5.0 min. No leaching of immobilised reagents was observed during a period
of at least one hour. Pre-swelling the sensors with water increased the reaction rate and the total turnover number of the
enzyme. In a dry atmosphere at 4 °C the sensors were found to be stable for at least two weeks. 相似文献
103.
104.
We compute the analytic expression of the probability distributions FAEX,+ and FAEX,− of the normalized positive and negative AEX (Netherlands) index daily returns r(t). Furthermore, we define the α re-scaled AEX daily index positive returns r(t)α and negative returns (−r(t))α, which we call, after normalization, the α positive fluctuations and α negative fluctuations. We use the Kolmogorov-Smirnov statistical test as a method to find the values of α that optimize the data collapse of the histogram of the α fluctuations with the Bramwell-Holdsworth-Pinton (BHP) probability density function. The optimal parameters that we found are α+=0.46 and α−=0.43. Since the BHP probability density function appears in several other dissimilar phenomena, our result reveals a universal feature of stock exchange markets. 相似文献
105.
Using Meldrum and van der Walt's scheme we successfully define (generalized) semigroup near-rings which are the extensions of their ring counterpart. Some standard semigroup ring results are extended. We define contracted objects for (generalized) semigroup near-rings and show (generalized) matrix near-rings are just a special case as in rings. This theory encompasses (generalized) matrix, group, and (generalized) polynomial near-rings. 相似文献
106.
We define nilpotent and strongly nilpotent elements of a module M and show that the set 𝒩 s (M) of all strongly nilpotent elements of M over a commutative unital ring R coincides with the classical prime radical β cl (M) the intersection of all classical prime submodules of M. 相似文献
107.
M. Fleck P. Becker L. Bayarjargal R. Ochrombel L. Bohatý 《Crystal Research and Technology》2008,43(2):127-134
Large single crystals of the polar (point group mm 2) compound tris(glycine) zinc chloride, (NH3CH2COO)3 · ZnCl2, were grown from aqueous solutions. The refractive indices were measured in the wavelength region from 365 nm to 1083 nm and an unpolarised absorption spectrum was recorded (transparency range from 260 to 1550nm). The phase matching conditions for second harmonic generation were analysed: both, type I (ss‐f) and type II (sf‐f) are possible in the red and near IR region. All five components of the piezoelectric tensor [dijk ] were determined; the maximum values of longitudinal and transverse piezoelectric effects are less than one half of d111 of α‐quartz. In addition, a redetermination of the crystal structure (including location of H atoms) is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
108.
Regio‐ and Enantio‐selective Chemo‐enzymatic C−H‐Lactonization of Decanoic Acid to (S)‐δ‐Decalactone
Jack Manning Michele Tavanti Joanne L. Porter Nico Kress Sam P. DeVisser Nicholas J. Turner Sabine L. Flitsch 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(17):5724-5727
The conversion of saturated fatty acids to high value chiral hydroxy‐acids and lactones poses a number of synthetic challenges: the activation of unreactive C?H bonds and the need for regio‐ and stereoselectivity. Here the first example of a wild‐type cytochrome P450 monooxygenase (CYP116B46 from Tepidiphilus thermophilus) capable of enantio‐ and regioselective C5 hydroxylation of decanoic acid 1 to (S)‐5‐hydroxydecanoic acid 2 is reported. Subsequent lactonization yields (S)‐δ‐decalactone 3 , a high value fragrance compound, with greater than 90 % ee. Docking studies provide a rationale for the high regio‐ and enantioselectivity of the reaction. 相似文献
109.
Dr. Nico Röder Dr. Tomasz Marszalek Daniel Limbach Prof. Wojciech Pisula Prof. Heiner Detert 《Chemphyschem》2019,20(3):463-469
π-Conjugated molecules with the shape of St. Andrew′s cross have been synthesized via fourfold Huisgen reaction. Four 2,5-diaryl-1,3,4-oxadiazol arms are attached to a central pyrazine nucleus. These fluorescent stars, when decorated with a rim of eight alkoxy side chains are discotic liquid crystals. Depending on the substitution pattern, the width of the liquid phase varies within a broad range of 25 °C to 250 °C. In their liquid crystalline phase, the molecules assemble in a typical hexagonal columnar supramolecular arrangement. 相似文献
110.
The computer‐aided design of polymers is one of the holy grails of modern chemical informatics and of significant interest for a number of communities in polymer science. This paper outlines a vision for the in silico design of polymers and presents an information model based on modern semantic web technologies, thus laying the foundations for achieving the vision.