Model based soft-sensor for on-line determination of substrate

A software sensor for on-line determination of substrate was developed based on a model for fed-batch alcoholic fermentation process and on-line measured signals of ethanol, biomass, and feed flow. The ethanol and biomass signals were obtained using a colorimetric biosensor and an optical sensor developed in previous works that permitted determination of ethanol at a concentration of 0–40 g/L and biomass of 0–60 g/L. The volume in the fermentor could be continuously calculated using the total measured signal of the feed flow. The results obtained show that the model used is adequate for the proposed software sensor and determines continuously the substrate concentration with efficiency and security during the fermentation process.     

Transport properties of normal liquid helium: comparison of various methodologies

We revisit the problem of self-diffusion in normal liquid helium above the lambda transition. Several different methods are applied to compute the velocity autocorrelation function. Since it is still impossible to determine the exact result for the velocity autocorrelation function from simulation, we appeal to the computation of short-time moments to determine the accuracy of the different approaches at short times. The main conclusion reached from our study is that both the quantum mode-coupling theory and the numerical analytic continuation approach must be regarded as a viable and competitive methods for the computation of dynamical properties of quantum systems.     

Structure of diaqua(itaconato) cadmium(II), [Cd(C5H4O4)(OH2)2]

[Cd(C₅H₄O₄)(OH₂)₂] (1), crystallizes in the monoclinic system, space groupP2₁/n, with lattice parametersa=7.323(2),b=16.028(6),c=7.202(2) Å, β=113.11(1)°, andZ=4. The Cd atom coordinates to seven oxygens in a monocapped trigonal antiprism fashion. The antiprisms share one vertex to form chains which run approximately parallel to thec axis. The itaconate ligands link the chains to form layers which stack along theb axis.     

Novel water-soluble bacteriochlorophyll derivatives for vascular-targeted photodynamic therapy: synthesis, solubility, phototoxicity and the effect of serum proteins

New negatively charged water-soluble bacteriochlorophyll (Bchl) derivatives were developed in our laboratory for vascular-targeted photodynamic therapy (VTP). Here we focused on the synthesis, characterization and interaction of the new candidates with serum proteins and particularly on the effect of serum albumin on the photocytotoxicity of WST11, a representative compound of the new derivatives. Using several approaches, we found that aminolysis of the isocyclic ring with negatively charged residues markedly increases the hydrophilicity of the Bchl sensitizers, decreases their self-association constant and selectively increases their affinity to serum albumin, compared with other serum proteins. The photocytotoxicity of the new candidates in endothelial cell culture largely depends on the concentration of the serum albumin. Importantly, after incubation with physiological concentrations of serum albumin (500-600 microM), WST11 was found to be poorly photocytotoxic (>80% endothelial cell survival in cell cultures). However, in a recent publication (Mazor, O. et al. [2005] Photochem. Photobiol. 81, 342-351) we showed that VTP of M2R melanoma xenografts with a similar WST11 concentration resulted in approximately 100% tumor flattening and >70% cure rate. We therefore propose that the two studies collectively suggest that the antitumor activity of WST11 and probably of other similar candidates does not depend on direct photointoxication of individual endothelial cells but on the vascular tissue response to the VTP insult.     

Quantum mode-coupling theory for binary mixtures

We extend the quantum mode-coupling theory of neat liquids to the case of binary mixtures, in order to study supercooled liquids where quantum fluctuations may compete with thermal fluctuations. We apply the theory to a generic model of a binary mixture of Lennard-Jones particles. Our treatment may be used to study quantum aging and exotic glass melting scenarios in structural supercooled quantum liquids.     

Topical use of liposomal copper palmitate formulation blocks porphyrin-induced photosensitivity in rats

Photodynamic therapy (PDT) is a new treatment modality that uses porphyrin derivatives and visible light, especially for the treatment of cancer. However, PDT with certain photosensitisers can cause prolonged skin photosensitization. This is particularly true for Photofrin II (Photofrin)-mediated PDT where patients are required to avoid direct exposure to sunlight for a period of 4-6 weeks. This is the only long-term adverse reaction to the drug. Recent studies have shown that topical copper treatment avoids this type of inflammatory reaction. In this study, we have tested the efficiency of the liposomal formulation of copper palmitate on porphyrin-photosensitized rats. Initially, adult male Sprague-Dawley rats were rendered photosensitive either by administration of Photofrin or aminolevulinic acid (ALA), a precursor of protoporphyrin IX (PpIX). Prior to this, their dorsal skin was shaved and treated topically with a cream consisting of either empty or copper palmitate-encapsulated liposomal formulation. After being kept in a dimmed light environment, the rats were exposed to visible light, and inflammatory responses were inspected. Histological studies revealed that no inflammatory cells were present at the skin sites treated with liposomal cream containing copper palmitate in the Photofrin-sensitized group while no reduction in the number of inflammatory cells was observed at the skin samples treated with the empty liposomes. In conclusion, the data demonstrate the significant protective effect of topically-applied liposome-encapsulated copper palmitate against both Photofrin and ALA-induced PpIX photosensitivity.     

A parallel electromagnetic molecular logic gate

A theoretical study of transport through a three-terminal molecular ring in the presence of a magnetic field is presented. The physical principles necessary to achieve logic operations based on the Aharonov-Bohm effect are discussed. We show that a proper combination of a gate potential and a realistic magnetic field can be used to obtain parallel logic operations such as AND and AND+NOT.     

Über Metallkomplexe heterocyclisch substituierter Formazane und Azomethine

Zusammenfassung Es wurden zwei neue Formazane, und zwar 1-Phenyl-5-(2-carboxyphenyl)-3-(3-methyl-2-chinoxalyl)-formazan und 1-Phenyl-5-(2-carboxyphenyl)-3-(3-methyl-2-chinolyl)-formazan synthetisiert. Diese Verbindungen bilden mit Uranyl-, Kobalt-und Nickelionen gut definierte Komplexe. Bei ihren Uran- und Kobaltkomplexen wurde ein Metall/Formazan-Verhältnis von 12, bei den Nickelkomplexen dagegen 11 festgestellt. Außerdem wurden Kobalt- und Nickelkomplexe des 3-Methylchinoxalin-2-aldehyd-o-hydroxy-anils mit einem Metall/Formazan-Verhältnis von 12 dargestellt.

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Metal complexes of heterocyclic substituted formazans and azomethines

Two new formazans, 1-phenyl-5-(2-carboxyphenyl)-3-(3-methyl-2-quinoxalyl)-formazan and 1-phenyl-5-(2-carboxyphenyl)-3-(3-methyl-2-quinolyl)-formazan have been synthesized. These compounds form well defined complexes with uranyl, cobalt and nickel ions. The ratio of metal/formazan in uranium and cobalt complexes is 12, in nickel complexes 11. Besides, cobalt and nickel complexes of 3-methyl-quinoxaline-aldehyde-o-hydroxy-anil were synthesized with a metal/azomethine ratio of 12.

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Teil der DissertationB. Ocakcioglu, Univ. Istanbul 1969.     

(Liquid + liquid) equilibria of (water + propionic acid + alcohol) ternary systems

(Liquid + liquid) equilibrium (LLE) data of the solubility (binodal) curves and tie-line end composition were examined for mixtures of {water (1) + propionic acid (2) + octanol or nonanol or decanol or dodecanol (3)} at T = 298.15 K and 101.3 ± 0.7 kPa. The reliability of the experimental tie-line data was confirmed by using the Othmer-Tobias correlation. The LLE data of the ternary systems were predicted by UNIFAC method. Distribution coefficients and separation factors were evaluated for the immiscibility region.     

Identification of SARS-CoV-2 Receptor Binding Inhibitors by In Vitro Screening of Drug Libraries

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) global pandemic. The first step of viral infection is cell attachment, which is mediated by the binding of the SARS-CoV-2 receptor binding domain (RBD), part of the virus spike protein, to human angiotensin-converting enzyme 2 (ACE2). Therefore, drug repurposing to discover RBD-ACE2 binding inhibitors may provide a rapid and safe approach for COVID-19 therapy. Here, we describe the development of an in vitro RBD-ACE2 binding assay and its application to identify inhibitors of the interaction of the SARS-CoV-2 RBD to ACE2 by the high-throughput screening of two compound libraries (LOPAC^®1280 and DiscoveryProbeTM). Three compounds, heparin sodium, aurintricarboxylic acid (ATA), and ellagic acid, were found to exert an effective binding inhibition, with IC50 values ranging from 0.6 to 5.5 µg/mL. A plaque reduction assay in Vero E6 cells infected with a SARS-CoV-2 surrogate virus confirmed the inhibition efficacy of heparin sodium and ATA. Molecular docking analysis located potential binding sites of these compounds in the RBD. In light of these findings, the screening system described herein can be applied to other drug libraries to discover potent SARS-CoV-2 inhibitors.