Immobilization in biotechnology and biorecognition: from macro- to nanoscale systems

Biological molecules such as enzymes, cells, antibodies, lectins, peptide aptamers, and cellular components in an immobilized form are extensively used in biotechnology, in biorecognition and in many medicinal applications. This review provides a comprehensive summary of the developments in new immobilization materials, techniques, and their practical applications previously developed by the authors. A detailed overview of several immobilization materials and technologies is given here, including bead cellulose, encapsulation in ionotropic gels and polyelectrolyte complexes, and various immobilization protocols applied onto surfaces. In addition, the review summarises the screening and design of an immobilization protocol, practical applications of immobilized biocatalysts in the industrial production of metabolites, monitoring, and control of fermentation processes, preparation of electrochemical/optical biosensors and biofuel cells.     

On the Finite Spectral Triple of an Almost-Commutative Geometry

In this short communication, we examine the relevance of the signature of the space-time metric in the construction of the product of a pseudo-Riemannian spectral triple with a finite triple describing the internal geometry. We obtain arguments favoring the appearance of SU(2) and U(1) as gage groups in the standard model.     

Synthesis and study of new rod-like mesogens containing 2-aminothiophene unit

We present a synthesis and mesomorphic properties of a new series of rod-like mesogens. All the compounds possess a substituted 2-aminothiophene unit as a main element in the structure attached to a stilbene moiety with a terminal alkyloxy chain (OR¹, OR² where R¹=C_nH_2n+1, R²=C_mH_2m+1; n, m ranging from 6 to 12). The synthesis of alkyloxybiphenyl substituted 2-aminothiophenes was carried out by the Gewald reaction and the appropriate reaction conditions were investigated. The liquid–crystalline properties were studied via polarizing optical microscopy, differential scanning calorimetry and X-ray diffraction. These materials exhibit nematic and/or smectic A phases. The influence of structural changes (variation in alkyloxy chain length and symmetry of the molecule) on mesogenic behaviour is discussed. Evaluation of UV–vis, fluorescent and electrochemical properties are also included.     

Asymmetric bioreduction of activated carbon–carbon double bonds using Shewanella yellow enzyme (SYE-4) as novel enoate reductase

Shewanella yellow enzyme (SYE-4), a novel recombinant enoate reductase, was screened against a variety of different substrates bearing an activated double bond, such as unsaturated cyclic ketones, diesters, and substituted imides. Dimethyl- and ethyl esters of 2-methylmaleic acid were selectively reduced to (R)-configured succinic acid derivatives and various N-substituted maleimides furnished the desired (R)-products in up to >99% enantiomeric excess. Naturally occurring (+)-carvone was selectively reduced to (?)-cis-dihydrocarvone and (?)-carvone was converted to the diastereomeric product, respectively. Overall SYE-4 proved to be a useful biocatalyst for the selective reduction of activated CC double bonds and complements the pool of synthetic valuable enoate reductases.     

On the multi‐colored Ramsey numbers of cycles

For a graph L and an integer k≥2, R_k(L) denotes the smallest integer N for which for any edge‐coloring of the complete graph K_N by k colors there exists a color i for which the corresponding color class contains L as a subgraph. Bondy and Erdos conjectured that, for an odd cycle C_n on n vertices, They proved the case when k = 2 and also provided an upper bound R_k(C_n)≤(k+ 2)!n. Recently, this conjecture has been verified for k = 3 if n is large. In this note, we prove that for every integer k≥4, When n is even, Sun Yongqi, Yang Yuansheng, Xu Feng, and Li Bingxi gave a construction, showing that R_k(C_n)≥(k?1)n?2k+ 4. Here we prove that if n is even, then © 2011 Wiley Periodicals, Inc. J Graph Theory 69: 169‐175, 2012     

Secondary ion mass spectrometry and alpha-spectrometry of electrodeposited thorium films

The main aim of this work was the preparation of samples with thorium content on the steel discs by electrodeposition for determination of natural thorium isotope by alpha spectrometry and secondary ion mass spectrometry and finding out their possible linear correlation between these methods. The analysis of the composition of surface was other aim of study. Discs were measured by alpha spectrometer. After that, alpha spectrometry discs were analyzed by TOF-SIMS IV, which is installed in the International Laser Centre in Bratislava. The integral and normalized intensities of isotope of ²³²Th and intensities of ions of ThO⁺, ThOH⁺, ThO₂H⁺, Th₂O₄H⁺, ThO₂ ^?, ThO₃H^?, ThH₃O₃ ^? a ThN₂O₅H^? were measured. The linear correlation is between surface’s weights of Th and intensities of ions of Th⁺ from identified in SIMS spectra. We found out the chemical binding between thorium and oxygen and hydrogen on the surface of samples by SIMS method. Obtained intensities of ions ²³²ThO⁺, ²³²ThOH⁺, ²³²ThO₂H⁺ prove the presence of oxidized forms of thorium in the upper layers of surface. The oxidized ions predominate in univalent form of thorium up to deep about 3,000 nm.     

The Gould-Jacobs Reaction of5-Aminoquinoxaline

 Reaction of 5-aminoquinoxaline with alkoxymethylene derivatives affords the corresponding quinoxalinoaminoethylenes. These undergo a thermal cyclization to yield angularly annelated 10H-pyrido[2,3-f]quinoxalines. The structures of all products were deduced from their IR, UV, mass, ¹H, and ¹³C NMR spectra.     

3‐Methyl 5‐isopropyl 2‐methoxy­imino­methyl‐6‐methyl‐4‐(3‐nitro­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate

The crystal structure of the title compound, C₂₀H₂₃N₃O₇, consists of relatively isolated mol­ecules. The substituted 1,4‐di­hydro­pyridine ring adopts a flattened boat conformation. Both ester groups, at positions 3 and 5, have cis,cis geometry. The phenyl ring is nearly planar and is approximately perpendicular to the 1,4‐di­hydro­pyridine ring (dihedral angle 87.70°).     

Study of the possibility of using radon potential maps for identification of areas with high indoor radon concentration

Journal of Radioanalytical and Nuclear Chemistry - In this study, five different methods for determining the geogenic radon potential are compared in the Mochovce region, Slovakia. Based on these...