Photochemically modulated endothelial cell thrombogenicity via the thrombomodulin-tissue factor pathways

Photodynamic therapy (PDT) is based on a photochemical reaction using a photosensitizer and light to produce reactive oxygen species that have biological effects. Although its application in some fields is largely based on thrombosis, in the vascular setting thrombosis must be prevented. In this study we examined the effects of PDT on the changes in activity of thrombomodulin (TM) and tissue factor (TF) as important regulators of the coagulation process of endothelial cells. Human umbilical vein endothelial cells were treated with PDT (chloro-aluminum-sulfonated phthalocyanine, lambda = 630 nm) at different light-energy doses, and TM and TF levels were measured using fluorescence spectroscopy. Microparticles (MP) were analyzed using flow cytometry analysis. PDT alters the thrombogenic state of endothelial cells by causing decreased expression of TM and increased expression of functional TF in a light-energy dose-dependent way. PDT-treated endothelial cells shed large numbers of MP containing high levels of TF. TF functionality of PDT-treated cells, measured by a Factor Xa-generating assay, was high. TF was located mostly intracellularly and in MP. The disturbed anticoagulant balance described in this study may explain the occurrence of thrombosis induced by PDT and, if not contained, dispute the suitability of PDT as an adjuvant modality to treat vascular restenosis.     

Alkene Isomerisation Catalysed by a Ruthenium PNN Pincer Complex

The [Ru(CO)H(PNN)] pincer complex based on a dearomatised PNN ligand (PNN: 2‐di‐tert‐butylphosphinomethyl‐6‐diethylaminomethylpyridine) was examined for its ability to isomerise alkenes. The isomerisation reaction proceeded under mild conditions after activation of the complex with alcohols. Variable‐temperature (VT) NMR experiments to investigate the role of the alcohol in the mechanism lend credence to the hypothesis that the first step involves the formation of a rearomatised alkoxide complex. In this complex, the hemilabile diethylamino side‐arm can dissociate, allowing alkene binding cis to the hydride, enabling insertion of the alkene into the metal–hydride bond, whereas in the parent complex only trans binding is possible. During this study, a new uncommon Ru⁰ coordination complex was also characterised. The scope of the alkene isomerisation reaction was examined.     

Chiral separation by enantioselective liquid-liquid extraction

The literature on enantioselective liquid-liquid extraction (ELLE) spans more than half a century of research. Nonetheless, a comprehensive overview has not appeared during the past few decades. Enantioselective liquid-liquid extraction is a technology of interest for a wide range of chemists and chemical engineers in the fields of fine chemicals, pharmaceuticals, agrochemicals, fragrances and foods. In this review the principles and advances of resolution through enantioselective liquid-liquid extraction are discussed, starting with an introduction on the principles of enantioselective liquid-liquid extraction including host-guest chemistry, extraction and phase transfer mechanisms, and multistage liquid-liquid extraction processing. Then the literature on enantioselective liquid-liquid extraction systems is reviewed, structured on extractant classes. The following extractant classes are considered: crown ether based extractants, metal complexes and metalloids, extractants based on tartrates, and a final section with all other types of chiral extractants.     

The Set of {omega}-Limit Points of A Map of the Circle is Closed

Let f be a continuous self-map of the unit circle, S¹. The -limitpoints (x) of a point x are the set of all limit points of thesequence of iterates of f acting on x. We shall show that theset of all -limit points _xS¹(x) a closed set in S¹.     

Study of complexation reactions between alkali and alkaline-earth metal cations with dibenzo-18-crown-6(DB18C6) in mixed nonaqueous solvents using the conductometry method

The complexation reactions between alkali and alkaline-earth metal cations with DB18C6 were studied in acetonitrile-methanol (AN-MeOH) and tetrahydrofuran-threechloromethane (THF-CHCl₃) binary mixtures at different temperatures using the conductometric method. The obtained results show that in most cases, the DB18C6 forms 1:1 complexes with these metal cations and the stability of the complexes is affected by the nature and composition of the mixed solvents. The stability order of complexes in AN-MeOH binary systems was found to be Na⁺ > Li⁺, and in the case of THF-CHCl₃ binary mixtures was Na⁺ > Ba²⁺ > Li⁺. An anomalous and interesting behavior was observed for the case of complexation of a K+ ion with DB18C6 in the AN-MeOH binary mixture and also for complexation of Mg²⁺ and Ca²⁺ cations with this ligand in pure THF and also in THF-CHCl₃ binary systems. The values of the thermodynamic parameters (ΔH _c ^o and ΔS _c ^o ) for complexation reactions obtained from the temperature dependence of the stability constants and the results show that the complexes are both enthalpy-and entropy-stabilized. The text was submitted by the authors in English.     

Study of corrosion protection of mild steel by eco-friendly silane sol–gel coating

The effects of dipping duration in the silane solution and the sol pH on the protective performance of an eco-friendly silane sol–gel coating consisting a mixture of tetraethoxysilane, methyltriethoxysilane and glycidyloxypropyltrimethoxysilane applied on mild steel substrate were studied in this paper using electrochemical techniques and surface analysis. In consistency with the data obtained from electrochemical impedance spectroscopy and polarization curves, electrochemical current noise fluctuation analysis, appearance of the power spectral density plots and noise resistance indicated the most efficient sol pH and immersion time in the silane solution. In this regard, field emission type scanning electron microscopy images and water contact angle values revealed impact of the sol pH on the film structure. The enhancement in protective performance of the hybrid coating resulting from optimum immersion in the silane solution with appropriate pH was connected to the film homogeneity and higher cross linking and thickness as well. Moreover, a good trend correlation was observed between the noise resistance and low-frequency impedance modulus data.     

Enantioselective liquid-liquid extraction of (R,S)-phenylglycinol using a bisnaphthyl phosphoric acid derivative as chiral extractant

This study demonstrates that enantioseparation by liquid-liquid extraction can be done in a continuous flow mode on both laboratory and industrial scale and is a promising technique that could become a competitive alternative for crystallization or chromatographic approaches. We studied the enantioselective liquid-liquid extraction of phenylglycinol (Pgl) using a bisnaphthyl phosphoric acid extractant. Batch experiments were performed to estimate extraction model parameters. The system was described using an extraction mechanism with homogeneous organic phase complexation. The complexation constants were very large, in the order of 10⁸-10¹⁰ L/mol in the temperature range 279<T<303 K. The developed model was then used to design a multistage countercurrent extraction process with Centrifugal Contactor Separator (CCS) equipment. This study demonstrates that high purity (70% ee) with a reasonable yield (36%) can be obtained for a moderately selective system (α=1.7) with only six extraction stages. The technology is potentially applicable to a wide range of racemates.     

A Pattern Dictionary Method for Anomaly Detection

In this paper, we propose a compression-based anomaly detection method for time series and sequence data using a pattern dictionary. The proposed method is capable of learning complex patterns in a training data sequence, using these learned patterns to detect potentially anomalous patterns in a test data sequence. The proposed pattern dictionary method uses a measure of complexity of the test sequence as an anomaly score that can be used to perform stand-alone anomaly detection. We also show that when combined with a universal source coder, the proposed pattern dictionary yields a powerful atypicality detector that is equally applicable to anomaly detection. The pattern dictionary-based atypicality detector uses an anomaly score defined as the difference between the complexity of the test sequence data encoded by the trained pattern dictionary (typical) encoder and the universal (atypical) encoder, respectively. We consider two complexity measures: the number of parsed phrases in the sequence, and the length of the encoded sequence (codelength). Specializing to a particular type of universal encoder, the Tree-Structured Lempel–Ziv (LZ78), we obtain a novel non-asymptotic upper bound, in terms of the Lambert W function, on the number of distinct phrases resulting from the LZ78 parser. This non-asymptotic bound determines the range of anomaly score. As a concrete application, we illustrate the pattern dictionary framework for constructing a baseline of health against which anomalous deviations can be detected.