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Thick-target PIXE analysis was applied to the study of electrokinetic soil remediation technique. In order to simulate radioactive soil contamination by ¹³⁷Cs, salt of stable cesium was mixed with soil samples. These soil samples were subjected to electrolysis for up to 36 hours with a field gradient of ≈ 1-3 V/cm. After the electrolysis, we measured the distribution of Cs concentration in the soil along the electrolysis cell by PIXE analysis. LX-rays of cesium were used for the analysis. The Cs concentrations in the drain water sampled from the cathode well were also evaluated. After the electrolysis the migration of cesium from the anode to the cathode was clearly observed. Water supply into the anode well enhanced the removal rate. We found that the main driving force of the migration of Cs⁺ observed in this work was not electrophoretic migration, but electroosmotic flow in the soil samples. Owing to the spectral interference by major metallic elements in the soil, the minimum detectable concentration of cesium by the present method was limited to ≈ 800 ppm.

This communication is devoted to nature determination and quantification by PIXE of metals contained in proteins after their separation by PolyAcrylamide Gel Electrophoresis (PAGE). After the electrophoresis, the gel is dried and each track is scanned with a 2.5 MeV proton beam which triggers metal X-ray fluorescence and then, allows to determine the type of metals contained in an electrophoretic band. For quantitative determination of the amount of the metal contained inside the band, the characteristic X-ray peak area is compared with those obtained with polyacrylamide gels doped with the same metal. The normalization has been achieved by using RBS measurements on the gel itself.

The procedure presented seems to be a very useful multielementary method for the metal content analysis and for the determination of the metal amounts inside proteins after their separation by electrophoresis. Furthermore it allows to check if metals remain bound to proteins.

Using a hybrid simulation method, structural and dynamic response properties of chain macromolecules are studied in a heterogeneous gel matrix in presence of an electrophoretic field E(t) = E_b + E_ssin(2π ft), where E_b is the static field and E_s is the amplitude of sinusoidal field of frequency f. We find that the oscillating field enhances the macromolecular mobility at E_s > E_b while it becomes ineffective at E_s < E_b, consistent with the experimental work of Masubuchi et al. Enhanced segmental and global movement of molecules at E_s > E_b leads to interesting effects such as (i) a significant decrease in molecular clustering, (ii) reduced radius of gyration, and (iii) its linear response to E_b. Power law behavior of molecular motion, i.e., the variation rms displacement (R) with the time steps (t), R ∝ t^ν, is sensitive to temperature, molecular weight, and field.

A new direct numerical simulation scheme, called "Smoothed Profile (SP) method," is presented. The SP method, as a direct numerical simulation of particulate flow, provides a way to couple continuum fluid dynamics with rigid-body dynamics through smoothed profile of colloidal particle. Our formulation includes extensions to colloids in multicomponent solvents such as charged colloids in electrolyte solutions. This method enables us to compute the time evolutions of colloidal particles, ions, and host fluids simultaneously by solving Newton, advection-diffusion, and Navier–Stokes equations so that the electro-hydrodynamic couplings can be fully taken into account. The electrophoretic mobilities of charged spherical particles are calculated in several situations. The comparisons with approximation theories show quantitative agreements for dilute dispersions without any empirical parameters.

One of the major issues with Extreme ultraviolet lithography (EUVL) is mask defects, which can occur by particle contamination. Gaussian Diffusion Sphere Model (GDSM) was developed to predict particle deposition velocity considering electrophoresis in addition to Brownian diffusion and gravitational settling of particles. For the validation of GDSM, the particle deposition velocities predicted using GDSM were compared with the computational fluid dynamics (CFD) simulation data. The improved GDSM predicted the particle deposition velocity correctly and had fast calculation time. Using the improved GDSM, in an electric field ranging from 0 V/cm to 1000 V/cm, the effects of both attractive electrophoresis and repulsive electrophoresis were evaluated. For the case considering electrophoresis, not only diffusion but also electrophoresis was dominant for the deposition velocity for submicron particles. Repulsive electrophoresis caused the deposition velocity to decrease. However, when the electric field strength was less than 100 V/cm, deposition was not small enough to be ignored. The deposition velocity was analyzed according to free-stream velocity. The effect of free-stream velocity was noticeable under repulsive electrophoresis, whereas it was suppressed under attractive electrophoresis.

Mathematical and numerical models for studying the electrophoresis of topologically nontrivial molecules in two and three dimensions are presented. The molecules are modeled as polygons residing on a square lattice and a cubic lattice whereas the electrophoretic media of obstacle network are simulated by removing vertices from the lattices at random. The dynamics of the polymeric molecules are modeled by configurational readjustments of segments of the polygons. Configurational readjustments arise from thermal fluctuations and they correspond to piecewise reptation in the simulations. A Metropolis algorithm is introduced to simulate these dynamics, and the algorithms are proven to be reversible and ergodic. Monte Carlo simulations of steady field random obstacle electrophoresis are performed and the results are presented.

The application of lattice-Boltzmann methods to electroviscous transport problems is discussed, generalising the moment propagation method for convective-diffusion problems. As a simple application, electro-osmotic flow in a parallel-sided slit is analysed, and the results compared favourably with available analytic solutions for this geometry.

We discuss the motion of a charged macromolecule in an ionized fluid in a finite region governed by the interaction of the electrical field described by the Poisson–Boltzmann equation and Stokes' equation. Both the surface of the macromolecule and the external surface of the container are supposed to be sufficiently regular. The case of a fluid occupying an infinite region is also discussed assuming an approximation hypothesis on the electrical field.

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The red V₂O₅ sol was prepared by facile alternating stirring and ultrasonic dispersion route. A V₂O₅ film fabricated on ITO-PET by electrophoresis method was used to demonstrate a flexible electrochromic device. The effects of applied voltage and electrophoresis time for V₂O₅films were investigated in detail. When the electrophoresis time was kept 30 s, the applied voltage was above 3 V to deposit uniform V₂O₅-PET film. The electrophoresis time could more significantly regulate the deposition of V₂O₅ on ITO-PET film. A flexible electrochromic device with “sandwich” structure was fabricated using V₂O₅ film, and its electrochromic performance of the device was evaluated. The flexible V₂O₅ electrochromic devices show the multicolor electrochromic performance of yellow, yellow-green, green and orange-red. The coloration efficiency values of V₂O₅ devices were 21.6 cm²C${}^{-1}$ (from initial yellow to green) and 26.9 cm²C${}^{-1}$ (from green to orange-red), respectively, and the highest transmittance modulation range was 51% at 741 nm. The work provided a facile and green method for fabrication of flexible V₂O₅ electrochromic device.

Alignment of peaks in electropherograms or chromatograms obtained from experimental techniques such capillary electrophoresis remains a significant challenge. Accurate alignment is critical for accurate interpretation of various classes of nucleic acid analysis technologies, including conventional DNA sequencing and new RNA structure probing technologies. An automated alignment algorithm was developed based on dynamic programming to align multiple-peak time-series data both globally and locally. This algorithm relies on a new peak similarity measure and other features such as time penalties, global constraints, and minimum-similarity scores and results in rapid, highly accurate comparisons of complex time-series datasets. As a demonstrative case study, the developed algorithm was applied to analysis of capillary electrophoresis data from a Selective 2'-Hydroxyl Acylation analyzed by Primer Extension (SHAPE) evaluation of RNA secondary structure. The algorithm yielded robust analysis of challenging SHAPE probing data. Experimental results show that the peak alignment algorithm corrects retention time variation efficiently due to the presence of fluorescent tags on fragments and differences in capillaries. The tools can be readily adapted for the analysis other biological datasets in which peak retention times vary.

The persistence length and the overlap concentration (c*) of poly(ethylene oxide) (PEO) and hydroxyethylcellulose (HEC) with similar molecular weight in 1 × TBE buffer were studied by laser light scattering and viscometry. Their effect on DNA separation was investigated by capillary electrophoresis. It was determined that the persistence length of HEC was at least 5 times higher than that of PEO. Therefore, the c* of HEC was smaller than that of PEO by a factor of ca. 2.5. It was also found that the c* values determined by laser light scattering were much lower than those by viscometry. We attributed it to the state of polymer chains in which c* was measured: laser light scattering determined the c* in ultradilute solution where the polymer chains were in the static state; while viscometry determined the c* in dilute or semidilute concentration region with polymer chains being in the hydrodynamic flowing state. When used in DNA separation, polymer chains were in different states due to the disturbance of DNA molecules, making c* region dependent. When the real concentration was normalized by c*, PEO and HEC showed almost equal performance in separating ΦX174/Hae III DNA digest in dilute solution, even though their persistence lengths were quite different.

In the present study, the activity of the new water-soluble cationic meso-tetra(4-N-oxyethylpyridyl)porphyrin and its Zn, Ag and Co metal derivatives as anti-tumor agents was explored. The tumor was induced by 7,12-dimethylbenz[a]antracene (DMBA) on rats of Wistar strain. The levels of DNA damage induced by porphyrins T4OEPyP, AgT4OEPyP, ZnT4OEPyP and CoT4OEPyP in tumor tissue were analyzed. Thermodynamic parameters of DNA were investigated by thermal melting method and differential scanning microcalorimetry to understand the differences in DNA structure of three types of rat: normal, dieseased with tumor, and treated by porphyrins. Agarose gel electrophoresis method was used to detect porphyrin-induced apoptosis or necroses. Based on the data obtained, we concluded that the investigated ZnTOEPyP and AgTOEPyP porphyrins have more anti-tumor activity than CoTOEPyP and TOEPyP.

This paper reviews recent progress in studies on the migration of charged species, including charged lipids, membrane-attached proteins and vesicles, and integrated membrane proteins, in lipid bilayer membranes under an external electric field. The migration of these charged substances is controlled by the interplay of electrophoresis and electroosmosis. This phenomenon can be employed to separate the charged lipids and membrane-attached proteins, and concentrate integrated membrane proteins.

Multi-walled carbon nanotubes films formed randomly aligned laterally by electrophoresis. Multi-walled carbon nanotubes with lengths of about 10 μ was shortened and functionalized by a mixture of sulfuric and nitric acid. The functional groups on carbon nanotubes were elaborated by FT-IR. Chemically shortened MWCNTs disperse in organic and aqueous solvent and deposited on electrode vertically-aligned by applying a constant DC electric field. The alignment of MWCNTs was observed by scanning electron microscopy. It also the effect of various substrates on alignment of multi-walled carbon nanotubes was investigated.

Five populations of Drosophila melanogaster that had been selected for postponed aging were compared with five control populations using two-dimensional protein gel electrophoresis. The goals of the study were to identify specific proteins associated with postponed aging and to survey the population genetics of the response to selection. A total of 321 proteins were resolvable per population; these proteins were scored according to their intensity. The resulting data were analyzed using resampling, combinatoric, and maximum parsimony methods. The analysis indicated that the populations with postponed aging were different from their controls with respect to specific proteins and with respect to the variation between populations. The populations selected for postponed aging were more heterogeneous between populations than were the control populations. Maximum parsimony trees separate the selected populations, as a group, from their controls, thereby exhibiting a homoplastic pattern.