对甲苯磺酰氯催化的meso-四芳基卟啉的合成

报道了一种改进了的meso-四芳基卟啉合成方法.利用对甲苯磺酰氯催化吡咯和芳香醛缩合生成中间物卟啉原,卟啉原中间物在紫外光照射下被空气氧化生成四芳基卟啉.该方法所用催化剂价廉易得,氧化过程绿色.整体反应条件简单,易于操作,产率高.     

Barrier effect and coupled transport in the electrodialysis of metal complexonate solutions

The electrodialysis of an aqueous solution of an alkaline earth complex with ethylenediaminetetraacetic acid (EDTA) was studied in a wide range of current densities. The curve of the complexonate flow across an anionite membrane versus current density has three characteristic sections. The first section corresponds to a linear increase in the flow as a function of current density, the second to a decrease in the flow and decomposition of the complex (barrier effect), and the third to an increase in the complexonate flow due to the transport coupled with the flow of hydroxyl ions formed in the dissociation of water molecules at the interface of the solution and the anionite membrane. Conditions for complete separation of the singly and doubly charged cations were found.     

Validation of the Charm MRL-3 for fast screening of beta-lactam antibiotics in raw milk

The biochemicals utilized in the Charm MRL beta-Lactam test (8 min test) were applied to faster flowing lateral components to create a new 3 min, one-step beta-lactam test called Charm MRL-3 (Charm Sciences Inc., Lawrence, MA). This new test was validated at T&V-ILVO according to Commission Decision 2002/657/EC. The following analytical parameters were checked: test specificity, detection capability, and test robustness (impact of deviation of the test protocol, and impact of the milk composition, batch differences of reagents). Further, the suitability of the Charm MRL-3 to screen heat-treated milk or milk from animal species other than the cow was also tested. Finally, the test was integrated in the monitoring of dairy samples to check the occurrence of false-negative or false-positive results, and the test was also included in a national ring trial and an international proficiency study. The results proved that the Charm MRL-3 is a fast, simple, and reliable cows' milk test that can be used at the farm level in order to prevent tanker milk contamination, or at the entrance of the dairy plant to screen tanker milk for the presence of beta-lactam antibiotics.     

Comparative properties of Amazonian oils obtained by different extraction methods

Pequi (Caryocar brasiliense Camb.), baba?u (Orbignya phalerata Mart.), buriti (Mauritia flexuosa), and passion fruit (Passiflora edulis) oils were studied to determine their antibacterial, antioxidant and cytotoxic activities, as well as their total phenol and carotenoid contents. The fatty acid contents were determined by GC-MS. The three types of passion fruit oils studied were refined, cold pressed or extracted from seeds in a Soxhlet apparatus. The oils thus obtained showed differences in antioxidant activity and carotenoid content, but were similar in regard to total phenols. Buriti and pequi had the highest carotenoid contents, while refined and cold pressed passion fruit oil displayed the highest antioxidant activity. Pequi oil was the only oil to display antibacterial and cytotoxic activity.     

Bis(2-pyridylimino)isoindolato iron(II) and cobalt(II) complexes: structural chemistry and paramagnetic NMR spectroscopy

Condensation of phthalodinitrile and 2-amino-5,6,7,8-tetrahydroquinoline gave the bis(2-pyridylimino)isoindole protioligand 1 (thqbpiH) in high yield. Deprotonation of thqbpiH (1) using LDA in THF at -78 °C yields the corresponding lithium complex [Li(THF)(thqbpi)] (2) in which the lithium atom enforces almost planar arrangement of the tridentate ligand, with an additional molecule of THF coordinated to Li. Reaction of cobalt(II) chloride or iron(II) chloride with one equivalent of the lithium complex 2 in THF led to formation of the metal complexes [CoCl(THF)(thqbpi)] (3a) and [FeCl(THF)(thqbpi)] (3b). The paramagnetic susceptibility of 3a,b in solution was measured by the Evans method (3a: μ(eff) = 4.17 μ(B); 3b: μ(eff) = 5.57 μ(B)). Stirring a solution of 1 and cobalt(II) acetate tetrahydrate in methanol yielded the cobalt(II) complex 4 which was also accessible by treatment of 3a with one equivalent of silver or thallium acetate in DMSO. Whereas 3a,b were found to be mononuclear in the solid state, the acetate complex 4 was found to be dinuclear, the two metal centres being linked by an almost symmetrically bridging acetate. For all transition metal complexes paramagnetic (1)H as well as (13)C NMR spectra were recorded at variable temperatures. The complete assignment of the paramagnetic NMR spectra was achieved by computation of the spin densities within the complexes using DFT. The proton NMR spectra of 3a and 3b displayed dynamic behaviour. This was attributed to the exchange of coordinating solvent molecules by an associative mechanism which was analysed using lineshape analysis (ΔS(≠)= -154 ± 25 J mol(-1) K(-1) for 3a and ΔS(≠) = -168 ± 15 J mol(-1) K(-1) for 3b).     

A rapid and reversible colorimetric assay for the characterization of aminated solid surfaces

The covalent immobilization of synthetic or natural macromolecular compounds containing amino groups onto polystyrene (PS) solid surfaces is of great interest in diagnostic applications. A sensitive assay allowing the determination of reactive end groups is therefore a powerful tool for predicting the performance of the active surface. Recently, we reported the use of the Coomassie brilliant blue (CBB) colorimetric reagent to quantify protonated groups (N⁺) in linear and dendritic structures in solution (Coussot et al., Polym Int 58(5):511–518, 2009). In this work, a simple method using CBB dye for the characterization of PS aminated solid surfaces is developed. The proposed amino density estimation by colorimetric assay (ADECA) method is based on the reversible complexation of the dye with the N⁺ groups on solid surfaces. The assay measures the released dye thanks to the use of a unique sodium carbonate–methanol buffer. Thereby, for the first time, the same surface can be used for characterization and for further coupling applications. A surface density of four N⁺ groups per square nanometer can be measured in PS microwell format, the whole characterization being done within 30 min. Performances of this new colorimetric-based method are detailed. The ADECA method is further demonstrated to be useful for the characterization of aminated polypropylene and glass materials with various sizes and shapes.     

Carleman estimates for stratified media

We consider anisotropic elliptic and parabolic operators in a bounded stratified media in Rn characterized by discontinuities of the coefficients in one direction. The surfaces of discontinuities cross the boundary of the domain. We prove Carleman estimates for these operators with an arbitrary observation region.     

On chaotic extensions of dynamical systems

In this paper, inspired by some results in linear dynamics, we will show that every dynamical system (X,f), where f is a continuous self-map on a separable metric space X, can be extended to a chaotic (in the sense of Devaney) dynamical system in an isometric way.     

The existence of asymptotically stable solutions for a nonlinear functional integral equation with values in a general Banach space

Motivated by the recent known results about the solvability and existence of asymptotically stable solutions for nonlinear functional integral equations in spaces of functions defined on unbounded intervals with values in the n-dimensional real space, we establish asymptotically stable solutions for a nonlinear functional integral equation in the space of all continuous functions on R₊ with values in a general Banach space, via a fixed point theorem of Krasnosel’skii type. In order to illustrate the result obtained here, an example is given.     

Variational sets: Calculus and applications to nonsmooth vector optimization

We develop elements of calculus of variational sets for set-valued mappings, which were recently introduced in Khanh and Tuan (2008) [1] and [2] to replace generalized derivatives in establishing optimality conditions in nonsmooth optimization. Most of the usual calculus rules, from chain and sum rules to rules for unions, intersections, products and other operations on mappings, are established. Direct applications in stability and optimality conditions for various vector optimization problems are provided.