Preasymptotic multiscaling in the phase-ordering dynamics of the kinetic Ising model

The evolution of the structure factor is studied during the phase-ordering dynamics of the kinetic Ising model with conserved order parameter. A preasymptotic multiscaling regime is found as in the solution of the Cahn-Hilliard-Cook equation, revealing that the late stage of phase-ordering is always approached through a crossover from multiscaling to standard scaling, independently from the nature of the microscopic dynamics.Comment: 11 pages, 3 figures, to be published in Europhys. Let

Role of solvent for globular proteins in solution

The properties of the solvent affect the behavior of the solution. We propose a model that accounts for the contribution of the solvent free energy to the free energy of globular proteins in solution. For the case of an attractive square well potential, we obtain an exact mapping of the phase diagram of this model without solvent to the model that includes the solute-solvent contribution. In particular we find for appropriate choices of parameters upper critical points, lower critical points and even closed loops with both upper and lower critical points, similar to one found before [Macromolecules, 36, 5845 (2003)]. In the general case of systems whose interactions are not attractive square wells, this mapping procedure can be a first approximation to understand the phase diagram in the presence of solvent. We also present simulation results for both the square well model and a modified Lennard-Jones model.Comment: 18 pages, 9 figure

Synthesis and Functionalization of Small Silver Nanoparticles

Metal nanoparticles in general exhibit interesting properties due to their small sizes. This response shows up as an intense absorption band in the visible region making metallic nanoparticles ideal probes for medical imaging as well as for countless other applications. Functionalizing metallic nanoparticles with DNA enables targeted labeling, controlled by their base sequence. Another purpose of functionalization is to attach the nanoparticle to a DNA substrate allowing controlled bottom up engineering of nanoscale devices. Gold or gold-encapsulated silver is usually used for these purposes instead of bare silver due to the ease with which silver is oxidized although silver nanoparticles show more intense plasmon resonance. The functionalization of silver with DNA is difficult because their surfaces are easily oxidized. The goal of this experiment was to attach thiolated DNA strands to bare 5-10 nm silver nanoparticles proving that it can indeed be done without extensive modification of the functionalization procedure. In order for this to be accomplished silver nanoparticles were synthesized using two different methods: a UV light directed growth method and a sodium borohydride/sodium citrate buffered reduction method. The first method resulted in nanoparticles in the 10-15 nm range while the second resulted in smaller particles (5-10 nm). DNA was then attached to purified particles using a process that has previously been applied to gold nanoparticles. The functionalization was verified using UV-Vis spectroscopy (to measure changes in the Plasmon peak and concentration) and the stability of the final product in a 0.3 M sodium chloride solution. Several samples have exhibited minimal peak shifts and minimal concentration loss indicating that little or no silver was oxidized in the functionalization process. These samples also remained stable as the sodium chloride concentration was slowly brought up to 0.3 M. Control samples precipitated out of solution almost immediately upon the addition of sodium chloride. Successful functionalization of silver nanoparticles opens up the way for the addition of functionalized silver particles and their inherent optical properties onto DNA heterostructures where they can then be used as seeds for directed growth of nanowires or nanoprisms. This will be accomplished by adding target strands to the DNA structure that are complimentary to the sequence bound to the nanoparticles which then hybridize with the strands on the nanoparticle resulting the incorporation of the nanoparticle into the DNA heterostructure

Thin-film-integrated power inductor on Si and its performance in an 8-MHz buck converter

This paper presents a microinductor fabricated on silicon using electrochemical techniques that has high efficiency in a low power dc–dc converter. Small signal measurements show a flat frequency response up to 20 MHz with a self resonant frequency of 130 MHz. The inductance at low frequency is approximately 440 nH with a dc resistance of 0.5 Ω, and a high quality factor of 11.7 at 5.5 MHz. The current handling capability test shows less than 10% decrease in inductance at 500-mA current. The performance of the microinductor has been compared to a conventional chip inductor in a commercially available 8-MHz buck converter. The converter maximum efficiency when using the microinductor is shown to be approximately 3% lower than the one using the conventional discrete chip inductor. However, the profile of the microinductor is much lower than that of the discrete chip inductor. The maximum efficiency of the microinductor in the converter is estimated to be approximately 92%

Selective glucocorticoid receptor properties of GSK866 analogs with cysteine reactive warheads

Synthetic glucocorticoids (GC) are the mainstay therapy for treatment of acute and chronic inflammatory disorders. Due to the high adverse effects associated with long-term use, GC pharmacology has focused since the nineties on more selective GC ligand-binding strategies, classified as selective glucocorticoid receptor (GR) agonists (SEGRAs) or selective glucocorticoid receptor modulators (SEGRMs). In the current study, GSK866 analogs with electrophilic covalent-binding warheads were developed with potential SEGRA properties to improve their clinical safety profile for long-lasting topical skin disease applications. Since the off-rate of a covalently binding drug is negligible compared to that of a non-covalent drug, its therapeutic effects can be prolonged and typically, smaller doses of the drug are necessary to reach the same level of therapeutic efficacy, thereby potentially reducing systemic side effects. Different analogs of SEGRA GSK866 coupled to cysteine reactive warheads were characterized for GR potency and selectivity in various biochemical and cellular assays. GR-and NF kappa B dependent reporter gene studies show favorable anti-inflammatory properties with reduced GR transactivation of two non-steroidal GSK866 analogs UAMC-1217 and UAMC-1218, whereas UAMC-1158 and UAMC-1159 compounds failed to modulate cellular GR activity. These results were further supported by GR immuno-localization and S211 phospho-GR western analysis, illustrating significant GR phosphoactivation and nuclear translocation upon treatment of GSK866, UAMC-1217, or UAMC-1218, but not in case of UAMC-1158 or UAMC-1159. Furthermore, mass spectrometry analysis of tryptic peptides of recombinant GR ligand-binding domain (LBD) bound to UAMC-1217 or UAMC-1218 confirmed covalent cysteine-dependent GR binding. Finally, molecular dynamics simulations, as well as glucocorticoid receptor ligand-binding domain (GR-LBD) coregulator interaction profiling of the GR-LBD bound to GSK866 or its covalently binding analogs UAMC-1217 or UAMC-1218 revealed subtle conformational differences that might underlie their SEGRA properties. Altogether, GSK866 analogs UAMC-1217 and UAMC-1218 hold promise as a novel class of covalent-binding SEGRA ligands for the treatment of topical inflammatory skin disorders

Coaxial metal and magnetic alloy nanotubes in polycarbonate templates by electroless deposition

We present a novel technique for the preparation of coaxial metal and magnetic alloy nanotubes, which is demonstrated for the coaxial nanotubes of Ni/Co and Ni/CoNiFe alloys deposited in activated polycarbonate templates using electroless plating. For each metal or alloy the tube wall thickness was controlled to be less than 100 nm. The process involved two consecutive deposition steps from hypophosphite and/or borane reducing agent based electroless plating solutions. We further characterise the magnetic properties of the ternary magnetic alloy films and coaxial nanotubes. The coaxial tubes show homogenous wall thickness and composition, which is delineated from the magnetic measurements

Electroless thin film CoNiFe-B alloys for integrated magnetics on Si

Electroless magnetic thin films have been deposited from borane-based baths suitable for use in integrated magnetics on Si applications. The baths were developed for compatibility with standard photoresist for microfabrication of integrated magnetics on Si. The specific formulations, which differ from those reported previously, yield uniform, high saturation magnetisation (up to 2.15 T) deposits with low coercivity (<2 Oe). The resistivity of the film can be increased to minimise eddy current losses by using higher dimethylamine borane (DMAB) content or the inclusion of a second reducing agent, hypophosphite, to facilitate phosphorus codeposition of up to 7 at.%. The Ni content in the plating bath has been shown to exert significant influence over the composition, deposition rate and coercivity. XRD analysis suggests that the deposits consist of nanocrystalline phase with grains <20 nm. Such small grains are consistent with the observed low coercivity of the deposits

The effect of tempering temperature and time on the hardness of a 4130 alloy steel

The problem of this study was to investigate the effect of tempering temperature and tempering time on the hardness of a 4130 alloy steel. The objectives of this study were to determine: (a) the effect of tempering temperature on hardness, (b) the effect of tempering time on hardness, and (c) the interaction between tempering temperature and tempering time. This study used an experimental research design method. The factorial design was the two-factor, fixed-effects model. Tempering temperature and tempering time were the predictors and hardness was the criterion. Time intervals of 15, 30, 60, 120, and 180 minutes were used. Temperature levels of 100, 150, 200, 250, and 300 °c were used. The research design had six specimens randomly assigned to each of the 25 cells or treatment combinations for a total of 150 specimens. The specimen material was 4130 tubular alloy steel, 0.875 in. OD x 0.065 in. wall thickness x 2 in. length. All specimens were processed identically for the hardening step of the heat treating process. The six specimens from each cell were tempered according to that cell\u27s designated time interval and temperature level. Data were collected by evaluating specimen hardness on the Rockwell C scale. Two-way ANOVA was the statistical method used to test the three null hypotheses. A multiple comparison, using Dunnett\u27s test as the statistical method, was used to investigate simple effects by testing among the cell means. The researcher concluded, based on the findings of this study, that there was: (a) a statistically significant difference in hardness among the five predetermined temperature levels, (b) a statistically significant difference in hardness among the five predetermined time intervals, (c) statistically significant interaction between tempering temperature and tempering time, and (d) an individually statistically significant difference in hardness between cell 10 (150 °c, 180 minutes) and cells 2, 4, 5, 7, 13, 14, 15, and 17 through 25. Using omega squared (w2) as a measure of association between the independent and dependent variables, the data indicated that 47.93% of the variance of the hardness scores can be attributed to the differences in the tempering temperature levels, 2.66% can be attributed to the differences in the tempering time intervals, and 4.17% can be attributed to the interaction of the two independent variables

The Calcitonin and Glucocorticoids Combination: Mechanistic Insights into Their Class-Effect Synergy in Experimental Arthritis

PMCID: PMC3564948This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited