Basic Science Sector

Sugar and nucleoside identifications are important for the detection and treatment of dangerous diseases. In this study, a fluorescent boronic acid (3-(5-(dimethylamino) naphthalene-1-sulfonamido) phenyl) boronic acid (DNSBA) was bound to a diol quencher via a boronic ester linkage, and fluorescence recovery upon exposure to saccharides and nucleosides was demonstrated. Further, we successfully detected sugars and nucleosides in buffer systems. DNSBA expresses selectivity toward adenosine, fructose, sorbitol, and tartaric acid. Our investigations into the effects of pH on sensor sensitivity revealed that changes between the neutral and anionic forms of the boronic acid group, induced at high pH and/or in the presence of sugars or nucleosides, induce visible/optimal changes in DNSBA. DNSBA is responsive at pH = 8.21 whereas acidic media do not exhibit sensitivity. DNSBA can thus be useful in clinical applications as a novel sensor for sugars and nucleosides.

Selective electrodes based on the reineckate drugs ion pairs in a polyvinyl chloride (PVC) matrix membrane is proposed for the determination of clomipramine (CLO) and paroxetine (PRX) hydrochlorides. The ion-pair complexes of drug cations with reineckate anion are either dissolved in tetrahydrofuran solvent or dispersed in a PVC matrix, with dioctylphthalate or dioctyl sebacat plasticizers, and used as the ion-exchange membranes. The electrochemical response characteristics of electrodes incorporating these types of membranes are evaluated with regard to the effect of pH, foreign basic compounds, effect of soaking time and lifespan. A well defined internal electrode potential was achieved using Ag/AgCl disc in contact with the ion-pair electroactive membrane phase. The electrodes display a stable fast Nernstian response in the concentration ranges 10-2-10-7 mol L-1 for the two drug cations over the pH range 2-5, a short static response time less than 60s and response remain stable for at least 6 weeks. The lower limit of detection was 10-7 mol L-1 for both drugs. Determination of as low as 8 ?g mL-1 of drugs hydrochloride shows an average recovery of 98.75 and 100.6% and a mean standard deviation of 0.70 and 0.35 for CLO and PRX drugs, respectively. Selectivity coefficients for CLO and PRX drugs relative to a numbers of potential interfering substances were investigated. The electrodes exhibit useful analytical characteristics for determining CLO and PRX in some illicit powders. The results agree fairly well with those obtained by gas-liquid chromatography. The proposed electrodes are simple easy to construct and behave as symmetric ion selective electrodes (ISEs).

Two types of new pyridine-based azo dyes, namely, 4-(3-pyridylazo)-4-alkoxybenzoates with various alkoxychains and 4-(3-pyridylazo)-4-substituted benzoates bearing groups of different polarities, were prepared andinvestigated for their mesophase behaviour by differential scanning calorimetry and polarised light microscopy. Allhomologues of the former group were found to be mesomorphic, while all derivatives of the latter are non-mesomorphic. The structures of compounds prepared were confirmed via elemental analyses, IR, 1H-NMR and massspectra. Four types of angular 1:1 hydrogen-bonded supramolecular complexes were prepared via hydrogen-bondformation between each of the pyridine-based derivatives and two types of benzoic acids, namely, 4-alkoxy and4-substituted benzoic acids. The latter bear the polar groups (CH3O, CH3, Br and NO2) in addition to benzoicacid. Complexes were similarly investigated and it was found that three of them are mesomorphic while the fourthis not. The formation of 1:1 hydrogen-bonded supramolecular liquid crystals complexes was confirmed by FTIR spectroscopy.

A series of La1-xSbxFeO3 was prepared using the conventional solid state method. XRD revealed the formation of the orthorhombic structure with space group Pbnm. The data showed that, the molar magnetic susceptibility and coercive field Hc were increased from 9.16x10-3 to 26.9x10-3 emu/g.mole and 1196 to 5465 Oe from for LaFeO3 to La0.95Sb0.05FeO3 respectively. The coercive field (HC) of the sample with x= 0.05 increased 6 times than that of the parent LaFeO3 and the saturation magnetization (Ms) was increased from 0.1614 emu/g for the parent LaFeO3 to 0.2654 emu/g for the doped sample. The dielectric constant (e/) was increased with increasing the Sb+3 content. The ac conductivity (?) increases from 2.36x10-3 W-1.m-1 for the LaFeO3 to 30x10-3 W-1.m-1 for the sample La0.95Sb0.05FeO3 at T = 553 K and frequency 1MHz. The sample La0.95Sb0.05FeO3 is concluded to be a novel single phase multiferroic material

(1H-benzimidazol-2-ylmethyl)-(4-nitro-phenyl)-amine (L) and its Pd(II) and Pt(II) complexes have been synthesized as potential anticancer compounds and their structures were elucidated using a variety of physico-chemical techniques. The activation thermodynamic parameters were calculated using non-isothermal methods. Theoretical calculations invoking geometry optimization, charge distribution and molecular orbital description HOMO and LUMO were done using density functional theory.

Two novel series of monocyclic and tricyclic 5-(phenylazo)thiophene systems were synthesized based on 3-amino-2-thioxopyrimidinone and 2-cyanoacetamidothiophene derivatives 4 and 6. Functionalization of the pyrimidine ring in precursor 4 resulted in the formation of the target tricyclic condensed thiophenes 7, 12, and 13a,b, by the application of a variety of addition, substitution, and condensation reactions.

The reaction of 2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[ b]thiophene with ethylcyanoacetate gave 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[ b]thiophen-2-yl)-acetamide. The latter was used to synthesize different he terocyclic derivatives comprising thiophene,thiazole, pyrazole, pyridine, pyrimidine, and c oumarin rings. The mechanistic and syntheticpathways depended on regioselective attack and/or cyclization by the cyanoacetamidomoiety in the key precursor on various chemical reagents.

The reaction of the cyanoacetylhydrazine (1) with ?-bromoketones (2a-c) gave the hydrazide-hydrazone derivatives 3a-c. The latter compounds underwent ready cyclization when heated in sodium ethoxide to form the 1,3,4-oxadiazine derivatives 4a-c. The reaction of 3a with hydrazines gave the 1,3,4-triazine derivatives 7a,b. Compounds 3a-c and 7a,b underwent some heterocyclizations when treated with some reagents to afford coumarin, 1,2,4-triazine, pyridazine and pyrazole derivatives. The antimicrobial and antifungal activities of the newly synthesized products were measured which showed that most of have high activities.

Molecules, 16: 16-27(2011) IF: 1.988

Phenacyl-malononitrile derivatives 1a,b react with dimethylformamide dimethylacetal (DMFDMA) in refluxing toluene to afford the enaminones 2a,b respectively. Compounds 2a and 2b react with the hydrazine hydrate 3a and phenyl hydrazine 3b in refluxing ethanol to afford the pyridazine

Nanocrystalline MnFe2O4 ferrite was prepared by using autocombustion technique (flash). Themicrostructure and magnetic properties are studied. The results of XRD and TEM clarified that, this ferrite isnanosized with particle size (39 nm). Magnetic measurements showed a ferromagnetic behavior with TC = 613 K, the saturation magnetization Ms = 13.71 emu/g

We study the nucleus-nucleus total reaction cross sections for stable nuclei, in the energy region from 30AMeVto about 1A GeV, and find them to be in proportion to

In this paper, Crank-Nicholson method for solving fractional wave equation is considered. The stability and consistency of the method are discussed by means of Greschgorin theorem and using the stability matrix analysis. Numerical solutions of some wave fractional partial differential equation models are presented. The results obtained are compared to exact solutions.

In this study, we study the numerical solutions of singularly perturbed convection-reaction-diffusionproblem over a square. Two different approaches are used to study the problem namely: Finite Element Method (FEM) based on a posteriori error estimate, and Variational Iteration Method (VIM). In this study, we use theadaptive h-refinement based on the a posteriori error estimate. Numerical simulation for the solution of theproposed problem using FEM and VIM is given. From this simulation we can found that the finite elementmethod gives the solution with excellent agreement compared with the exact solution. Also, it's found that VIMis invalid for some values of the perturbed parameter g, but FEM overcome on this shortcoming.

We investigate two stable methods for solving the system of linear algebraic equations arising
from plane, singular boundary-value problems for Laplace’s equation for rectangular domains [1, 21]. The
dynamical systems method and the variational regularization method are applied to derive stable solutions
for these systems, and the results are compared with those obtained from the QR-factorization technique
contaminated with noise. The results put in evidence the difficulties that may arise from the use of the QRfactorization
method due to instability.

Protein feeds in the European Union (EU) cover only 25% demand for protein, what oblige the particular members to import feeds with a high protein content, where the main place have soybean meal. The share of this feed in total quantity of feeds utilization in EU is about 9%. Yearly consumption of soybean meal in EU is about 32mln ton, from what 5.6% it falls on Poland (Rynek Pasz, 2010). Poland, as another countries, is importer of protein feeds, mainly soybean meal.

The existence of multiperiodic and multisoliton solutions for parabolic one-dimensional scalarand vector equations is studied. It is shown that these solutions exist for a scalar equation if it is completelyintegrable and linearizable, while they exist for vector equations when they are completely integrable. Thegeometric structure of the solutions is similar to that of multidimensional equations. As applications, vector

A new formula expressing explicitly the derivatives of Bernstein polynomials of any degree andfor any order in terms of Bernstein polynomials themselves is proved, and a formula expressingthe Bernstein coefficients of the general-order derivative of a differentiable function in termsof its Bernstein coefficients is deduced.

In this paper, we consider the explicit finite-difference method for solving variable order fractional heat equation with a linear source term, via the Caputo concept of variable order fractional