Can temporal analysis of optical coherence tomography statistics report on dextrorotatory-glucose levels in blood?

We report the use of optical coherence tomography (OCT) for measuring dextrorotatory-glucose (D-glucose) in liquid phantoms and in drawn blood based on temporal dynamics of light scattering. The presence of D-glucose alters the medium viscosity, thus affecting the Brownian motion of the scatterers (polystyrene microspheres (PMS) in phantoms, red blood cells (RBCs) in blood) as measured by OCT. To quantify the effect, the signal autocorrelation functions were measured from M-mode OCT data and exponentially fit to obtain the decorrelation times. These were then related to translational (and rotational, in case of asymmetric scatterers) diffusion coefficients which enabled the determination of D-glucose-controlled medium viscosity. Obtained viscosily values agreed well with the literature, and showed expected increase with D-glucose concentrations. Whole blood smears were imaged with microscope and another effect of added glucose, that of red blood cell deformation, was also observed. This phantom and blood OCT study demonstrates the technique’s ability to detect and quantify D-glucose presence in non-flowing liquid suspensions, and suggests several additional research routes necessary to determine its potential for in vivo applications.     

A class of methods based on non-polynomial sextic spline functions for the solution of a special fifth-order boundary-value problems

A family of fourth and second-order accurate numerical schemes is presented for the solution of fifth-order boundary-value problems with two-point-boundary conditions. The non-polynomial sextic spline functions are applied to construct the numerical algorithms. This approach generalizes polynomial spline algorithms, and provides solution at every point of range of integration. Convergence of the methods is discussed through standard convergence analysis. A numerical illustration is given to show the pertinent features of the technique.     

Kinetic properties of dromedary pancreatic lipase: A comparative study on emulsified and monomolecular substrate

We demonstrated the use of X-ray photoelectron spectroscopy (XPS) to study DNA hybridization. Target DNA labeled with hexachloro-fluorescein (HEX) was hybridized to DNA arrays with four different probes. Each probe dot of the hybridized arrays was detected with XPS. The XPS Cl2p peak areas were found to decrease with an increase in mismatched bases in DNA probes. The Cl2p core-level peak area ratio of a probe perfectly matched to one, two and three base-mismatched probes accorded well with the results of conventional fluorescent imaging, which shows that XPS is a potential tool for analyzing DNA arrays. The DNA arrays’ hybridization efficiency was assessed by the molar ratio of chlorine to phosphorus in a DNA strand, which was determined from the relevant XPS Cl2p and P2p core-level peak areas after hybridization. This could provide a new method to detect DNA hybridization efficiency.     

Mössbauer studies and magnetic studies of Ni doped orthoferrites PrFe1−xNixO3 (x≤0.3)

The magnetic properties of polycrystalline PrFe_1−xNi_xO₃ (x≤0.3) system were studied using Mössbauer spectroscopy and magnetization measurements. The Mossbauer spectra exhibit six line spectra which loses its sharpness as the Ni substitution increases within the system. As the Ni concentration in the system increases, the hyperfine field and isomer shift shows decrease, which is vivid from the sluggish nature of the sextets. The small value of quadrupole splitting confirms the octahedral environment of the Fe⁺³ ions. The magnetization curves show the reversible behavior and represent the fall in negative molecular field leading to AFM frustration. From these results, we conclude that sagging in the spectra reveals the change from antiferromagnetic state to ferromagnetic state, which can be attributed to mixed state of Fe⁺³ ions i.e. high spin (HS) and low spin (LS) which is a consequence of progressive collapse of Hund’s rule due to HS→LS transition. These results confirm the weak ferromagnetic component due to canted-AFM spin arrangement of Fe³⁺ magnetic moments.     

Structural and electronic properties of rock salt phase of ZnO under compression

Structural and electronic properties of rock salt phase of ZnO under high pressure have been reinvestigated in the light of some recent experimental results. Behavior of direct and indirect energy band gap under increasing pressure is analyzed on account of overlapping of p (O) and d (Zn) orbitals and the results are compared with other theoretical studies. An empirical relation involving elemental electronegativity is suggested to estimate the change in band gap under increasing pressure. Furthermore, phase transformation of ZnO into other possible structures is also discussed and their structural and electronic properties analyzed.     

Ion-beam-induced ferromagnetism in Ca-doped LaMnO3 thin films grown on Si (100)

The ion-bean-induced room temperature ferromagnetic ordering in pulsed laser deposited Ca-doped LaMnO₃ thin films grown on Si (100) are presented in the present study. In addition to this, changes bought by the ion beam in structural, morphological and electrical properties are presented. Dense electronic excitation produced by high energy 120?MeV Ag⁹⁺ ion irradiation causes change in surface roughness, crystallinity and strain. It is also evident that these excitations induce the magnetic ordering in this system. The observed modifications are due to the large electronic energy deposited by swift heavy ion irradiation. The appearance of ferromagnetism at 300?K in these samples after irradiation may be attributed to the canting of the antiferromagnetically ordered spins due to the structural distortion. It is observed that the irradiated films show higher resistance than unirradiated films for all the compositions.     

Optimization of linearity by use of a glass plate in carousel interferometers

Carousel interferometers are compact swinging interferometers, but their popularity is limited because of significant nonlinearity in rotational measurements. Introducing a glass plate in a rotating interferometer and optimizing its thickness has improved the linearity drastically. Computer simulations show reductions in nonlinearity of several orders of magnitude.