Exploiting flow injection system with mini-immunoaffinity chromatographic column for chondroitin sulfate proteoglycans assay

A flow injection (FI) system with a mini-immunoaffinity chromatographic column was used to perform on-line assays of specific proteoglycans. The 300-μL mini-column contained beads coupled with monoclonal antibodies against the specific sulfation pattern of chondroitin sulfate proteoglycans, which have been reported to be a potential biomarker for cancer. The amount of these proteoglycans present was estimated indirectly from their protein content using the Bradford assay, which is an alternative to a direct carbohydrate assay. The system developed was tested by assaying for chondroitin sulfate proteoglycans in sera from patients with various cancers and comparing the results to those obtained for sera from healthy people. The results indicated that this approach could be used as a cost-effective alternative system for determining the amount of these specific biomarker proteoglycans. The column could be reused at least 90 times, with each run consisting of 200 μL of serum sample diluted twofold; an analysis rate of 30 min per run was achieved, as compared to 4 h for a batch procedure.     

Review on screening and analysis techniques for hemoglobin variants and thalassemia

Thalassemia involves gene mutation that causes the production of an insufficient amount of normal structure globin chains while Hb variant involves gene mutation that causes the change in type or number of amino acid of the globin chain. It has been reported that some 200 million people worldwide had hemoglobinopathies of some sort. Attempts to develop effective and economical techniques for screening and analysis of thalassemia and Hb variants have become very important. In this review, we report the different techniques available, ranging from initial screening to extensive analysis, comparing advantages and disadvantages. Some indirect studies related to thalassemia indication and treatment follow-up are also included. We hope that information on these various techniques would be useful for some scientists who are working on development of a new technique or improving the existing ones.     

Effect of substrate temperature on electrical and magnetic properties of epitaxial La1−x Pb x MnO3 films

Epitaxial La_1−x Pb _x MnO₃ (LPMO) thin films, grown on (100) SrTiO₃ substrates by laser ablation technique at different temperatures between 600 and 850°C, have been characterized for electrical and magnetic properties. The temperature dependence of resistivity showed that the metal-insulator transition temperature (T _MI) decreases with increasing substrate temperature, which has been attributed to decrease in Pb content in the filsm. The YBa₂Cu₃O _x /La_1−x MnO₃ heterostructures, exhibiting both superconductivity and ferromagnetism, have been fabricated.     

Microwave absorption studies of MgB2 superconductor

Microwave absorption studies have been carried out on MgB₂ superconductor using a standard X-band EPR spectrometer. The modulated low-field microwave absorption signals recorded for polycrystalline (grain size ∼ 10 μm) samples suggested the absence of weak-link character. The field dependent direct microwave absorption has been found to obey a ✓H dependence with two different slopes, which indicated a transition from strongly pinned lattice to flux flow regime.     

Dielectric relaxation phenomena of rigid polar liquid molecules under giga hertz electric field

The dielectric relaxation phenomena of rigid polar liquid molecules chloral and ethyltrichloroacetate (j) in benzene, n-hexane and n-heptane (i) under 4.2, 9.8 and 24.6 GHz electric fields at 30°C are studied to show the possible existence of double relaxation times τ ₂ and τ ₁ for rotations of the whole and the flexible parts of molecules. The probability of showing double relaxation is more in aliphatic solvents indicating their nonrigidity. The symmetric and asymmetric distribution parameters γ and δ are obtained from X _ij ^′ /X _0ij and X _ij ^″ /X _0ij and w _j →0 where X _ij ^′ and X _ij ^″ are real and imaginary parts of the complex orientational susceptibility X _i ^* and X _0ij is the low frequency susceptibility which is real. X _ij ’s are involved with the measured dielectric relative permittivities ε _ij ^′ , ε _in ^″ , ε _0ij and ε _∞ij of solutions. The theoretical weighted contributions c ₁ and c ₂ towards dielectric dispersions by Fröhlich’s method are compared with the experimental ones obtained from the graphical variation of X _ij ^′ /X _0ij and X _ij ^″ /X _0ij with weight fractions w _j ’s at w _j → 0. The measured dipole moments μ ₂ and μ ₁ of the whole and the flexible part of a polar molecule in terms of the linear coefficients β’s of X _ij ^′ ’s with w _j ’s and the estimated τ ₂ and τ ₁ reveal their associations with aliphatic solvents. The theoretical dipole moments μ _theo’s from the available bond angles and bond moments of the substituent polar groups of the molecules with the estimated μ’s suggest the mesomeric, inductive and electromeric effects in them under GHz electric field.     

Olefin complexes of rhodium(I) containing the ligands but-3-enyldiphenylphosphine and diphenylpent-4-enylphosphine

But-3-enyldiphenylphosphine (mbp) and diphenylpent-4-enylphosphine (mpp) react with Rh₂Cl₂(C₂H₄)₄ (molar ratio $\text{2}\text{1}$ to form the four coordinate dimeric complexes Rh₂Cl₂(mbp)₂ and Rh₂Cl₂(mpp)₂ respectively, while but-3-enyldiphenylphosphine reacts with Rh₂Cl₂(C₂H₄)₄ (molar ratio $\text{4}\text{1}$) to form RhCl(mbp)₂, a five coordinate complex in the solid state. The dimers further react with sodium tetraphenylborate to give the π-bonded tetraphenylborate complexes Rh[mbp][C₆H₅)₄B] and Rh[i-mpp][(C₆H₅)₄B] where i-mpp = (C₆H₅)₂P(CH₂CH₂CHCHCH₃). RhCl(CO)(mbp)₂ reacts with sodium tetraphenylborate to form the five coordinate cationic complex [Rh(CO)(mbp)₂][(C₆H₅)₄B]. Both RhCl(CO)(mbp)₂ and RhCl(mbp)₂ react with hydrogen in methanol saturating the olefin to form RhCl[CO][(C₆H₅)₂P(C₄H₉)]₂ and Rh₂Cl₂[(C₆H₅)₂P(C₄H₉)]₂ respectively.     

Efficient Transformation of Furfuryl Alcohol Into Ethyl Levulinates via Alcoholysis Reaction Catalyzed by SnO2/H-Mordenite Catalyst

Catalysis Surveys from Asia - Catalytic production of ethyl levulinate by alcoholysis of furfuryl alcohol with ethanol was investigated over H-mordenite supported Sn catalyst under atmospheric N2...     

Exploiting guava leaf extract as an alternative natural reagent for flow injection determination of iron

Guava leaf extract is utilized as an alternative natural reagent for quantification of iron. The flow injection technique enables the use of the extract in acetate buffer solution without the need of further purification. Some properties of the extract such as its stability and ability to form a colored complex with iron were studied. The proposed system is an environmentally friendly method for determination of iron with less toxic chemical wastes.     

Five coordinate rhodium(I) olefin complexes containing the ligand bis(but-3-enyl)phenylphosphine

The complexes Rh₂X₂(bbp)₂ (X = Cl, Br or I; and bbp = bis(but-3-enyl)phenylphosphine) have been prepared. These complexes have been characterized as five coordinate dimers in which the unsaturated phosphine acts as a tridentate ligand. Carbon monoxide reacts reversibly with the dimers forming the five coordinate monomeric compounds RhX(CO)(bbp). Mass spectral, infrared, Raman, and proton magnetic resonance data are consistent with the above formulations.