Resolution of 1,1′-Binaphthyl-2,2′-Dicarboxylic Acid with Quinine: Structure of the Intermediate (<Emphasis Type="Italic">S</Emphasis>)-1,1′-Binaphthyl-2,2′-Dicarboxylate Dihydrate Diastereomeric Salt

Abstract  

Racemic 1,1′-binaphthyl-2,2′-dicarboxylic acid (BNDA) was resolved using quinine as the resolving agent. The structure of the resultant quininium (S)-1,1′-binaphthyl-2,2′-dicarboxylate dihydrate salt (1) was elucidated. The asymmetric unit contained one 1,1′-binaphthyl-2,2′-dicarboxylate anion, two quininium cations and two water molecules. The structure was solved successfully in the orthorhombic space group P2₁2₁2₁ with unit cell dimensions: a = 11.100(2) ?, b = 16.572(3) ?, c = 28.726(6) ?.     

Metabolic profiling using principal component analysis, discriminant partial least squares, and genetic algorithms

The aim of this study was to evaluate evolutionary variable selection methods in improving the classification of ¹H nuclear magnetic resonance (NMR) metabonomic profiles, and to identify the metabolites that are responsible for the classification. Human plasma, urine, and saliva from a group of 150 healthy male and female subjects were subjected to ¹H NMR-based metabonomic analysis. The ¹H NMR spectra were analyzed using two pattern recognition methods, principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA), to identify metabolites responsible for gender differences. The use of genetic algorithms (GA) for variable selection methods was found to enhance the classification performance of the PLS-DA models. The loading plots obtained by PCA and PLS-DA were compared and various metabolites were identified that are responsible for the observed separations. These results demonstrated that our approach is capable of identifying the metabolites that are important for the discrimination of classes of individuals of similar physiological conditions.     

Rapid state reduction of quantum systems using feedback control

We consider using Hamiltonian feedback control to increase the speed at which a continuous measurement purifies (reduces) the state of a quantum system, and thus to increase the speed of the preparation of pure states. For a measurement of an observable with equispaced eigenvalues, we show that there exists a feedback algorithm which will speed up the rate of state reduction by at least a factor of 2(N + 1)/3.     

Dispersion of a cloud of particles by a moving shock: Effects of the shape, angle of rotation, and aspect ratio

This paper discusses the particle-laden flow development from a cloud of particles in an accelerated flow behind a normal moving shock. The effects of the aspect ratio of a rectangular and ellipsoidal cloud and the cloud’s angle of attack with respect to the carrier flow are studied. Computations are performed with an in-house high-order weighted essentially non-oscillatory (WENO-Z) finite-difference scheme-based Eulerian-Lagrangian solver that solves the conservation equations in the Eulerian frame, while particles are traced in the Lagrangian frame. Streamlined elliptically shaped clouds exhibit a lower dispersion than blunt rectangular clouds. The averaged and root-mean-square locations of the particle coordinates in the cloud show that the cloud’s streamwise convection velocity increases with decreasing aspect ratio. With increasing rotation angle, the cross-stream dispersion increases if the aspect ratio is larger than unity. The particle-laden flow development of an initially moderately rotated rectangle is qualitatively and quantitatively comparable to the dispersion of an initially triangular cloud.     

About the formulation,verification and validation of the hypersonic flow solver Eilmer

We describe the formulation of the gas dynamics and high‐temperature thermochemical modules of the Eilmer code, an open‐source Navier–Stokes solver for transient compressible flow in two and three dimensions. The core gas dynamics formulation is based on finite‐volume cells, and the thermochemical effects are handled with specialised updating schemes that are coupled into the overall time‐stepping scheme. Verification of the code is explored via a number of case studies that use analytic and semi‐analytic solutions as comparison. These include both smooth and shocked flows and are used to demonstrate the order of spatial accuracy of the code. Cases include manufactured solutions for rather abstract inviscid and viscous flow, an idealised detonation wave supported by a curved body, and the transient flow of an idealised but high‐performance shock tube. Validation of the inviscid gas dynamics and thermochemical models is then explored using data from a selection of experimental studies. These studies include ballistic range experiments with chemically‐inert noble gases and high‐temperature chemically‐reacting air. These comparisons show that the code performs well and they provide a lesson in considering a range of experimental data rather than relying upon isolated data points for validation. These verification and validation cases are described in full detail and will be useful for other code developers of high‐temperature compressible flow solvers. Copyright © 2013 John Wiley & Sons, Ltd.     

Inclusion Compounds of the Host 9-(4-Methylphenyl)-9<Emphasis Type="Italic">H</Emphasis>-xanthen-9-ol with a Series of Organic Guests

Abstract  The host 9-(4-methylphenyl)-9H-xanthen-9-ol (H) forms inclusion compounds with the guests cyclohexane (H · ?CHEX), benzene (H · ?BENZ), 1,4-dioxane (H · ?DIOX), cyclohexanone (H · CYONE), N,N-dimethylformamide (H · DMF) and N,N-dimethylacetamide (H · DMA). For those guest molecules possessing electron acceptor atoms/functionalities hydrogen bonding with the host is the prominent mode of interaction and presents itself in the form of (Host)–OH···O(Guest) linkages. The cyclohexane and benzene guests however, occupy voids created by neighbouring host molecules which form hydrogen bonded dimers of the form (Host)–OH···O(Host). The structures of the inclusion compounds were investigated and their thermal stabilities determined. Selectivity experiments were also conducted. Graphical Abstract  The host 9-(4-methylphenyl)-9H-xanthen-9-ol (H) forms inclusion compounds with the guests cyclohexane (H · ?CHEX), benzene (H · ?BENZ), 1,4-dioxane (H · ?DIOX), cyclohexanone (H · CYONE), N,N-dimethylformamide (H · DMF) and N,N-dimethylacetamide (H · DMA). Crystal structures and thermal stabilities were determined. The host selectivity was also investigated.      

SPE–NMR metabolite sub-profiling of urine

NMR-based metabolite profiling of urine is a fast and reproducible method for detection of numerous metabolites with diverse chemical properties. However, signal overlap in the (1)H NMR profiles of human urine may hamper quantification and identification of metabolites. Therefore, a new method has been developed using automated solid-phase extraction (SPE) combined with NMR metabolite profiling. SPE-NMR of urine resulted in three fractions with complementary and reproducible sub-profiles. The sub-profile from the wash fraction (100?% water) contained polar metabolites; that from the first eluted fraction (10?% methanol-90?% water) semi-polar metabolites; and that from the second eluted fraction (100?% methanol) aromatic metabolites. The method was validated by analysis of urine samples collected from a crossover human nutritional intervention trial in which healthy volunteers consumed capsules containing a polyphenol-rich mixture of red wine and grape juice extract (WGM), the same polyphenol mixture dissolved in a soy drink (WGM_Soy), or a placebo (PLA), over a period of five days. Consumption of WGM clearly increased urinary excretion of 4-hydroxyhippuric acid, hippuric acid, 3-hydroxyphenylacetic acid, homovanillic acid, and 3-(3-hydroxyphenyl)-3-hydroxypropionic acid. However, there was no difference between the excreted amounts of these metabolites after consumption of WGM or WGM_Soy, indicating that the soy drink is a suitable carrier for WGM polyphenols. Interestingly, WGM_Soy induced a significant increase in excretion of cis-aconitate compared with WGM and PLA, suggesting a higher demand on the tricarboxylic acid cycle. In conclusion, SPE-NMR metabolite sub-profiling is a reliable and improved method for quantification and identification of metabolites in urine to discover dietary effects and markers of phytochemical exposure.     

Programmable large area digital microfluidic array with integrated droplet sensing for bioassays

We describe a new device concept for digital microfluidics, based on an active matrix electrowetting on dielectric (AM-EWOD) device. A conventional EWOD device is limited by the number of electrical connections that can be made practically, which restricts the number and type of droplet operations. In an AM-EWOD, the patterned electrodes of a conventional EWOD device are replaced by a thin film transistor (TFT) array, as found in a liquid crystal display (LCD), facilitating independent control of each electrode. The arrays can have many thousand individually addressable electrodes, are fully reconfigurable and can be programmed to support multiple simultaneous operations. Each element is 210 μm × 210 μm in size and contains a circuit that measures the electrical impedance of the liquid above it. This is used to determine the presence and size of a droplet, a method that can improve assay reliability and accuracy. This sensor provides feedback, error detection and closed loop control of an assay sequence. We describe the design, fabrication and testing of a 64 × 64 format AM-EWOD device with impedance sensor functionality. A colorimetric assay is implemented on the device and used to measure glucose in human blood serum. Results are compared with the same assay performed on a microtitre plate.     

17 e- rhenium dicarbonyl CO-releasing molecules on a cobalamin scaffold for biological application

Cyanocobalamin (B(12)) offers a biocompatible scaffold for CO-releasing 17-electron dicarbonyl complexes based on the cis-trans-[Re(II)(CO)(2)Br(2)](0) core. A Co-C≡N-Re conjugate is produced in a short time and high yield from the reaction of [Et(4)N](2)[Re(II)Br(4)(CO)(2)] (ReCORM-1) with B(12). The B(12)-Re(II)(CO)(2) derivatives show a number of features which make them pharmaceutically acceptable CO-releasing molecules (CORMs). These cobalamin conjugates are characterized by an improved stability in aqueous aerobic media over the metal complex alone, and afford effective therapeutic protection against ischemia-reperfusion injury in cultured cardiomyocytes. The non-toxicity (at μM concentrations) of the resulting metal fragment after CO release is attributed to the oxidation of the metal and formation in solution of the ReO(4)(-) anion, which is among the least toxic of all of the rare inorganic compounds. Theoretical and experimental studies aimed at elucidating the aqueous chemistry of ReCORM-1 are also described.