Globin chain separation by SDS polyacrylamide gel electrophoresis. Simple screening method for elongated hemoglobin chains

A simple method for the separation of hemoglobin chains from hemolysate or globin, by sodium dodecyl sulfate polyacrylamide gel electrophoresis, is described. The alpha, beta, and gamma chains can be clearly separated from each other. The alpha chain has the highest mobility, the beta chain has a slower mobility than the gamma chain, while the delta chain has about the same mobility as the beta chain. Hemoglobins with elongated chains can easily be detected by this method. Tak-beta, elongated by 11 residues, moves much more slowly than betaA but is much faster than alpha Constant Spring which is elongated by 31 residues. Screening of several individuals with slow-moving hemoglobins using this method led to the finding of a case with Hb Tak-beta thalassemia and other carriers of Hb Tak.     

Rupture of thin stagnant films on a solid surface due to random thermal and mechanical perturbations

A generalized formalism for the rupture of a nondraining thin film on a solid support due to imposed random thermal and mechanical perturbations, modeled as a Gaussian white noise, is presented. The evolution of amplitude of perturbation is described by a stochastic differential equation. The average film rupture time is the average time for the amplitude of perturbation to equal to the film thickness and is calculated by employing a first passage time analysis for different amplitudes of imposed perturbations, wavenumbers, film thickness, van der Waals and electrostatic interactions and surface tensions. The results indicate the existence of an optimum wavenumber at which the rupture time is minimum. A critical film thickness is identified based on the sign of the disjoining pressure gradient, below which the film is unstable in that the rupture time is very small. The calculated values of rupture time as well as the optimum wavenumber in the present analysis agree well with the results of linear stability analysis for immobile as well as completely mobile gas-liquid film interfaces. For stable films, the rupture time is found to increase dramatically with film thickness near the critical film thickness. As expected, the average rupture time was found to be higher for smaller amplitudes of imposed perturbations, larger surface potentials, larger surface tensions and smaller Hamaker constants.     

Synthesis and Structure of a Molecular Zinc Phosphate [(C12H8N2Zn)2(HPO4)(H2PO4)2]

A hydrothermal reaction of a mixture of ZnCO₃, phosphoric acid, 1, 10‐phenanthroline in H₂O gave rise to large plates of a new zinc phosphate, [(C₁₂H₈N₂Zn)₂(HPO₄)(H₂PO₄)₂], I . The structure consists of ZnO₃N₂ distorted trigonal‐bipyramidal and PO₄ tetrahedral units linked through their vertices to give rise to a zero‐dimensional molecular solid (monomer). The structure of the monomer appears to be similar to the secondary building unit (SBU) 4 = 1, commonly found in many fibrous zeolites. To our knowledge, this is the first time this building unit has been isolated. The structure, with a unique composition, is stabilized by hydrogen bond interactions between the terminal —OH groups forms a one‐dimensional molecular wire and also by strong π…π interactions between the 1, 10‐phenanthroline units. Photoluminescence studies show that there is a ligand‐to‐metal charge transfer (LMCT). Crystal data: orthorhombic, space group = Fdd2 (no. 43), a = 40.4669(1), b = 7.4733(2), c = 17.4425(5)Å, V = 5274.9(2)ų, Z = 8.     

Lattice parameter and thermal expansion of CsCl and CsBr by x-ray powder diffraction. II. Thermal expansion of CsBr from room temperature to 78.2 °K

The lattice parameters of CsBr at eight different temperatures from room temperature to 78.2 °K were measured and the true lattice parameters were obtained by the least squares method using the Nelson-Riley extrapolation function. Using these parameters the thermal expansion coefficients of CsBr were estimated at each temperature by fitting them into a cubic polynomial involving temperatureT. Theα _T thus obtained were compared with the values of earlier workers who used an interferometric technique and the agreement was found to be good.     

Effect of substrate temperature on structural, optical and electrical properties of pulsed laser ablated nanostructured indium oxide films

Nanocrystalline indium oxide (INO) films are deposited in a back ground oxygen pressure at 0.02 mbar on quartz substrates at different substrate temperatures (T_s) ranging from 300 to 573 K using pulsed laser deposition technique. The films are characterized using GIXRD, XPS, AFM and UV-visible spectroscopy to study the effect of substrate temperature on the structural and optical properties of films. The XRD patterns suggest that the films deposited at room temperature are amorphous in nature and the crystalline nature of the films increases with increase in substrate temperature. Films prepared at T_s ≥ 473 K are polycrystalline in nature (cubic phase). Crystalline grain size calculation based on Debye Scherrer formula indicates that the particle size enhances with the increase in substrate temperature. Lattice constant of the films are calculated from the XRD data. XPS studies suggest that all the INO films consist of both crystalline and amorphous phases. XPS results show an increase in oxygen content with increase in substrate temperature and reveals that the films deposited at higher substrate temperatures exhibit better stoichiometry. The thickness measurements using interferometric techniques show that the film thickness decreases with increase in substrate temperature. Analysis of the optical transmittance data of the films shows a blue shift in the values of optical band gap energy for the films compared to that of the bulk material owing to the quantum confinement effect due to the presence of quantum dots in the films. Refractive index and porosity of the films are also investigated. Room temperature DC electrical measurements shows that the INO films investigated are having relatively high electrical resistivity in the range of 0.80-1.90 Ωm. Low temperature electrical conductivity measurements in the temperature range of 50-300 K for the film deposited at 300 K give a linear Arrhenius plot suggesting thermally activated conduction. Surface morphology studies of the films using AFM reveal the formation of nanostructured indium oxide thin films.     

Studies on the growth,structural, optical,SHG and thermal properties of γ-glycine single crystal: An organic nonlinear optical crystal

Single crystals of the organic nonlinear optical material γ-glycine have been grown in the presence of Zinc sulphate by slow evaporation technique at ambient temperature for the first time. Bulk growth of γ-glycine single crystals was grown by Top-seeded solution growth method. The γ-phase of glycine was confirmed by powder X-ray diffraction and the FTIR analysis. Elemental analysis CHN was performed to confirm the non-inclusion of zinc sulphate species into the solution. Inductively coupled plasma optical emission spectrometry study (ICP-OES) was employed to quantify the concentration of Zinc element in the grown γ-glycine single crystals. The optical transmission was ascertained from UV–Vis–NIR spectrum. The optical band gap was estimated for γ-glycine single crystal using UV–Vis–NIR study. Differential scanning calorimetry analysis was employed to explore information about thermal stability, phase transition and melting point of the grown crystal. The second harmonic generation relative efficiency was measured by Kurtz and Perry powder technique.     

Effect of ZnO doping on the structural and optical properties of BaWO<Subscript>4</Subscript> thin films prepared using pulsed laser ablation technique

BaWO₄ doped with ZnO (2, 3, 5, 7 and 10 wt%) nanostructured films are prepared on quartz substrates by pulsed laser ablation. The films are post annealed at 900°C. GIXRD analysis of the post-annealed films reveal the change of orientation of scheelite tetragonal crystal growth from 1 1 2 reflection plane to 0 0 4 planes when doping concentration is more than 3 wt%. The AFM images show that film with 7 wt% ZnO doping concentration has good ceramic pattern with surface features giving a minimum value of rms surface roughness suitable for optoelectronic device applications. The optical transmittance and band-gap energy of the films are found to decrease considerably on postannealing which can be due to the increase in grain size of the crystallites on annealing. Thus doping with ZnO improves the surface features of the films and increases the optical band-gap energy.     

Transparent water repellent silica films by sol-gel process

Non-wettable surfaces with high contact angles and facile sliding angle of water droplets have received tremendous attention in recent years. The present paper describes the room temperature (∼27 °C) synthesis of dip coated water repellent silica coatings on glass substrates using iso-butyltrimethoxysilane (iso-BTMS) as a co-precursor. Emphasis is given to the influence of the hydrophobic reagent (iso-BTMS) on the water repellent properties of the silica films. Silica sol was prepared by keeping the molar ratio of tetraethoxysilane (TEOS) precursor, methanol (MeOH) solvent, water (H₂O) constant at 1:16.53:8.26 respectively, with 0.01 M NH₄F throughout the experiment and the molar ratio of iso-BTMS/TEOS (M) was varied from 0 to 0.965. The effect of M on the surface structure and hydrophobicity has been researched. The static water contact angle values of the silica films increased from 65° to 140° and water sliding angle values decreased from 42° to 16° with an increase in the M value from 0 to 0.965. The water repellent silica films are thermally stable up to a temperature of 280 °C and above this temperature the film shows hydrophilic behavior. The water repellent silica films were characterized by the Fourier Transform Infrared (FT-IR) Spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), % of optical transmission, thermal and chemical aging tests, humidity tests, static and dynamic water contact angle measurements.