Densitometric DNA Analysis in Agarose Electrophoretic Gels

JPC – Journal of Planar Chromatography – Modern TLC - Agarose gel electrophoresis is a basic separation tool used in molecular biology, mostly for qualitative DNA analysis. There are...     

Study of two large-dimension Murillo's paintings by means of macro X-ray fluorescence imaging,point X-ray fluorescence analysis,and stratigraphic studies

During the recent restoration of two large-dimension paintings by Murillo, entitled “Miracle of the loaves and fishes” and “Moses and the water from the rock of Horeb,” several studies about the materials employed for their execution were carried out. Macro X-ray fluorescence scanning technique was performed on both works complemented by point X-ray fluorescence and stratigraphic analyses, in order to characterize the different components of the paintings (i.e., ground layer, pigments, and binders). The results allowed us to better elucidate Murillo painting technique and his creative process. Ground layer was prepared in the usual fashion of the artist, using earths, calcium carbonate, iron oxide pigments, and white lead. The polichromy is composed of lead white mixed with various pigments, depending on the colour tone to be obtained in the pictorial composition: Red and yellow ochres, vermilion, azurite, smalt, and lead-tin yellow were the main pigments identified during our study. Finally, the presence of previous conservation treatments was evidenced by detecting pigments (zinc white, Prussian blue, etc.) not coeval with the artist palette.     

Methods of realisation of short rise-times of the cell voltage in pulse polarography

Three methods for producing a voltage step on the dropping mercury electrode cell, as required in pulse polarography, are considered: the double pulse shape of the potentiostat reference voltage, iR-compensation, and charge injection. On an analogue model two methods of iR-compensation are simulated and compared, with reference to their convenience for reducing the rise-time of the polarizing voltage. A charge injection technique is proposed in which the potentiostat reference voltage is derived from the cell voltage after charge injection by taking a sample of it and applying it to the reference input of the potentiostat.     

Colorimetric Cyanide Chemosensor Based on 1′,3,3′,4-Tetrahydrospiro[chromene-2,2′-indole]

A new class of chemosensors based on the 1′,3,3′,4-tetrahydrospiro[chromene-2,2′-indole] ring system, which detects cyanide with high specificity, is described. These chemosensors show a distinct color change when treated with cyanide in acetonitrile solution buffered with sodium phosphate, and this procedure is not affected by the presence of other common anions. The chemisensors exhibit high sensitivity to low concentrations of cyanide, meeting the European Union water quality control criterion of sensitivity below 0.05 mg L⁻¹, and show a very fast response within tens of seconds. The mechanism for detection is rationalized by the nucleophilic substitution of the phenolic oxygen atom at the indoline C-2 atom by the cyanide anion to form a stable indolylnitrile adduct and to generate the colored 4-nitrophenolate chromophore. These chemosensors can be synthesized by a simple procedure from commercially available starting materials.     

Search for CP violation in D± meson decays to ϕπ±

We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D(±)→K(+)K(-)π(±) and the Cabibbo-favored decays D(s)(±)→K(+)K(-)π(±) in the K(+)K(-) mass region of the ? resonance. Using 955 fb(-1) of data collected with the Belle detector, we obtain A(CP)(D+→?π+)=(+0.51±0.28±0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5. We find no evidence for direct CP violation.     

Thermal properties of PA 6 and PA 6 modified with copolyamides and layered silicates

This article focuses on the thermal properties of PA 6 and additives, i.e. ternary copolyamides, concentrates consisting of binary or ternary copolyamides + nanoadditive montmorillonite Bentonite 11958 or Cloisite 15A and PA 6 fibres modified with Bentonite, copolyamide and concentrate. The copolyamides are prepared from ε-caprolactam as a major comonomer and nylon salts AN2 from adipic acid + 1-(2-aminoethyl)piperazine and ADETA from adipic acid + diethylenetriamine. All copolyamides and concentrates exhibit lower melting temperatures T _m and lower melting enthalpies ΔH _m compared to neat PA 6. PA 6 fibres modified with 0.25–2.5 wt% MMT exhibit higher melting enthalpies in comparison with unmodified PA 6 fibres. PA 6 fibres modified with 10 wt% of ternary copolyamide containing 21.4 wt% of comonomers AN2 and ADETA have higher melting enthalpy as well. PA 6 fibres modified with 10 and 20 wt% of concentrate containing the same ternary copolyamide + 5 wt% of MMT have higher melting enthalpies and higher tensile strength in comparison with these characteristics of unmodified PA 6 fibres.     

Search for CP violation in the decays D(0)→K(S)(0)P(0)

We have searched for CP violation in the decays D(0)→K(S)(0)P(0) where P(0) denotes a neutral pseudoscalar meson that is either a π(0), η, or η' using KEKB asymmetric-energy e(+)e(-) collision data corresponding to an integrated luminosity of 791 fb(-1) collected with the Belle detector. No evidence of significant CP violation is observed. We report the most precise CP asymmetry measurement in the decay D(0)→K(S)(0)π(0) to date: A(CP)(D(0)→K(S)(0)π(0))=(-0.28±0.19±0.10)%. We also report the first measurements of CP asymmetries in the decays D(0)→K(S)(0)η and D(0)→K(S)(0)η': A(CP)(D(0)→K(S)(0)η)=(+0.54±0.51±0.16)% and A(CP)(D(0)→K(S)(0)η')=(+0.98±0.67±0.14)%, respectively.     

Search for CP violation in τ±→K(S)0π±ντ decays at Belle

We report on a search for CP violation in τ(±)→K(S)(0)π(±)ν(τ) decays using a data sample of 699 fb(-1) collected by the Belle experiment at the KEKB electron-positron asymmetric-energy collider. The CP asymmetry is measured in four bins of the invariant mass of the K(S)(0)π(±) system and found to be compatible with zero with a precision of O(10(-3)) in each mass bin. Limits for the CP violation parameter Im(η(S)) are given at the 90% confidence level. These limits are |Im(η(S))| < 0.026 or better, depending on the parametrization used to describe the hadronic form factors, and improve upon previous limits by 1 order of magnitude.     

Energetics of Formation of Nanocrystalline Structures in Finemet, Nanoperm and Hitperm Alloys

Processes controlling transformation in three rapidly quenched nanocrystal-forming systems, Finemet, Nanoperm and Hitperm, were analyzed using a novel approach which provides the distribution of true activation energies of nanocrystallization and their temperature dependencies. This approach yields new information with respect to the original local ordering of atoms in the amorphous phase and its influence on the formation of nanostructures. Additional information is extracted which allows to compare processes in the early stages of nanocrystallization with those at the end of the phase transformation.