Search results for "Electrophoresi"
showing 10 items of 1009 documents
Electrophoretic flow behaviour and mobility of colloidal fluids and crystals.
2007
We report on measurements of the electrophoretic mobility mu of charged colloidal spheres in the deionized state, where the suspensions show fluid or crystalline order. In the fluid state, parabolic flow profiles are observed due to electro-osmotic solvent flow. In the crystalline state, complex flow profiles occur due to additional crystal cohesion. The mobility mu then may inferred from the flow velocity averaged over the complete cell cross section as performed in our home built super-heterodyne Doppler velocimeter. For two particle species of 68 and 122 nm diameter we measured mu as a function of particle concentration. Starting from a plateau value at low concentration, mu decreases ap…
Monte Carlo simulation of DNA electrophoresis
1989
This paper describes an attempt to study the electrophoresis mobility of a DNA molecule in a gel by means of a Monte Carlo simulation. We find that the electrophoresis mobility mu can be well described by the empirical equation mu v kappa 1/N + kappa 2E2 with N being the number of monomers of the model chain and E being the applied field. For small E the data can merge into the linear response result mu = kappa 1/N. The paper also discusses necessary extensions of the present approach.
Theoretical and experimental study of the role of cell-cell dipole interaction in dielectrophoretic devices: application to polynomial electrodes
2013
BACKGROUND: We aimed to investigate the effect of cell-cell dipole interactions in the equilibrium distributions in dielectrophoretic devices. METHODS: We used a three dimensional coupled Monte Carlo-Poisson method to theoretically study the final distribution of a system of uncharged polarizable particles suspended in a static liquid medium under the action of an oscillating non-uniform electric field generated by polynomial electrodes. The simulated distributions have been compared with experimental ones observed in the case of MDA-MB-231 cells in the same operating conditions. RESULTS: The real and simulated distributions are consistent. In both cases the cells distribution near the elec…
A D-mannose-specific lectin from Gerardia savaglia that inhibits nucleocytoplasmic transport of mRNA.
1987
A new lectin has been isolated from the coral Gerardia savaglia by affinity chromatography, using locust gum as an absorbent, and D-mannose as eluant. Final purification was achieved by Bio-Gel P300 gel filtration. The agglutinin is a protein composed of two polypeptide chains with a Mr of 14800; the two subunits are not linked by disulfide bond(s). The isoelectric point is 4.8, the amino acid composition is rich in the acidic amino acids aspartic acid and glutamic acid. The absorption maximum for the protein was at 276 nm; with a molar absorption coefficient of 1.27 X 10(5) M-1 cm-1. The lectin precipitated erythrocytes from humans (A, B and O), sheep, rabbit and carp with a titer between …
2-D difference gel electrophoresis approach to assess protein expression profiles in Bathymodiolus azoricus from Mid-Atlantic Ridge hydrothermal vent…
2011
Hydrothermal vent mussels Bathymodiolus azoricus are naturally exposed to toxic chemical species originated directly from vent chimneys. The amount of toxic elements varies significantly among vent sites along the Mid-Atlantic Ridge and B. azoricus must be able to adapt to changes in hydrothermal fluid composition, temperature and pressure. The aim of this work was to study changes in the proteome in the "gill-bacteria complex" of mussels B. azoricus from three hydrothermal vent sites with distinct environmental characteristics using 2-D Fluorescence Difference Gel Electrophoresis (2-D DIGE). Results showed that 31 proteins had different expression profiles among vent sites and both cluster…
Electrophoresis of colloidal dispersions in the low-salt regime
2007
We study the electrophoretic mobility of spherical charged colloids in a low-salt suspension as a function of the colloidal concentration. Using an effective particle charge and a reduced screening parameter, we map the data for systems with different particle charges and sizes, including numerical simulation data with full electrostatics and hydrodynamics and experimental data for latex dispersions, on a single master curve. We observe two different volume fraction-dependent regimes for the electrophoretic mobility that can be explained in terms of the static properties of the ionic double layer.
Electropherotyping of human rotaviruses: An epidemiological survey of rotavirus infections in Sicily
1986
An electrophoretic analysis of rotavirus RNA segments was carried out on 522 faecal specimens, obtained from children hospitalized in Sicily in the period 1981/85. One hundred and one viral isolates could be characterized with respect to the electrophoretic pattern of their genomic RNAs. This analysis revealed that in 1981/82 different electropherotypes cocirculated in the infant population. In 1983 one of the patterns became prevalent; in 1984/85 only one electropherotype was detected, both in Palermo and Catania specimens. The serotyping showed that all viral strains with the prevalent electropherotype were subgroup II and serotype 1. These results contrast with the extensive genome varia…
Genotypic Analysis of E. coli Strains Isolated from Patients with Cystitis and Pyelonephritis
2012
BACKGROUND: Urinary tract infection is the most common health problem affecting millions of people each year, mainly caused by a large genetically heterogeneous group of Escherichia coli called uropathogenic E. coli This study investigates the genotypic analysis of E. coli strains isolated from patients with cystitis and pyelonephritis. METHODS: During 2008-2009, 90 E. coli strains were analyzed, consisting of 48 isolates causing pyelonephritis in children and 42 isolates causing cystitis. Having identified the strains by standard methods, they were subtyped by pulsed field gel electrophoresis (PFGE) and their corresponding patterns were compared using dendrogram. RESULTS: Sixty five PFGE p…
Nutritional, chemical, syneresis, sensory properties, and shelf life of Iranian traditional yoghurts during storage
2019
Tuluq and Torba yoghurts are traditional concentrates from Iran. Physicochemical, nutritional, and sensory properties of these yoghurts were studied along 60 days of storage. Results showed that, both pH and percentage of free whey decreased significantly (P < 0.05), while titratable acidity, total solid, salt, protein and fat content increased (P < 0.05) during storage. The yoghurt lipolysis decreased during the first 30 days and then increased during the storage. The indexes pH 4.6-soluble nitrogen/total nitrogen and non-protein nitrogen/total nitrogen in yoghurt samples decreased during first 30 days, possibly due to removing of low molecular weight nitrogenous compounds of Tuluq and Tor…
Analysis of protein composition of red wine in comparison with rosé and white wines by electrophoresis and high-pressure liquid chromatography-mass s…
2009
Wine proteins not only influence wine stability but are also being discussed as potential allergens. Proteins from red, rose, and white wines were enriched by dialysis and lyophilization followed by separation by SDS-PAGE. Significant differences were detected in the protein compositions of the analyzed wine varieties, and the major protein bands were identified by mass spectrometry after in-gel digestion with trypsin. In German Portugieser red wine, a total of 121 tryptic peptides were identified, which were attributed to 12 grape proteins and 6 proteins derived from yeast. Among the identified constituents are several proteins considered to influence wine stability and previously describe…