We report here on the successful incorporation of org. anions into a sol-gel film on Al as a means of enhancing the protection against corrosion. Following our previous study where we showed that hydrophobic sol-gel films provided pronounced corrosion inhibition, we studied the corrosion inhibition that phenylphosphonic acid (PPA) has when embedded inside a thin sol-gel coating on Al. The anion of this org. acid tends to stay inside a phenyltrimethoxysilane (PTMOS) based sol-gel film due to π-interactions. Our findings, which are derived primarily from potentiodynamic polarization measurements, electrochem. noise, SEM measurements and Auger electron spectroscopy (AES), clearly show that the org. phosphonate adds to the protection efficiency of the sol-gel film. [on SciFinder(R)]
Copolymers consisting of styrene and 4-chloromethylstyrene (CMS) were functionalized via reaction with 9-anthracenecarboxylic acid, providing the corresponding esters. Increasing degrees of functionalization were found to increase the glass transition temperature, influence chain packing density, and induce microphase separation in block copolymer structures. The approach demonstrated in this study facilitates the investigation of the relationship between structure of side-chain groups and polymer properties, providing a general approach for the study of the effect of chemical functionality on material properties of polymers.
In the presence of an 'Atmosphere Externality' and competitive behavior by households, a uniform commodity tax on the externality-generating good, attains the first best. If income redistribution is desirable, then personalized taxes are required for the second best optimum.
It has been argued that in the presence of an ‘Atmosphere Externality’ and competitive behavior by households, a uniform commodity tax on the externality-generating good attains the first best. It is demonstrated, however, that if income redistribution is desirable then personalized taxes are required for a second-best optimum. Each of these taxes is the sum of a uniform (across households) tax and a component, positive or negative, which depends on the household’s income and demand elasticities. Second-best optimal indirect taxes and rules for investment in externality-reducing measures are also considered.
Various aspects of the adsorption of Cd2+ on self-assembled monolayers (SAMs) of 4-heptadecylpyridine (HDpy) and 7-tridecyl-4-methyl-1,10-bipyridine (TMbipy) supported on an octadecylsilane (ODS)-modified Ge prism have been examined both ex situ (dry) and in situ (in the presence of aqueous solutions) using attenuated total reflection Fourier transform infrared spectroscopy. In direct analogy with the behavior found for a variety of genuine pyridine (py) and bipyridine (bipy) metal ion complexes, Cd2+ binding to both SAMs led to shifts in the skeletal vibrational modes of the corresponding uncoordinated ligands in the region 1650-1400 cm(-1), toward higher energies. Analysis of spectra acquired ex situ for HDpy/ODS/Ge and TMbipy/ODS/Ge before and after exposure to 0.1 mM [Cd2+] yielded values for the fraction of uncoordinated py, theta(py(un)), and uncoordinated bipy, theta(bipy(un)), of about 0.5 and about 0.1, respectively. The features attributed to the py(un) groups for spectra collected for HDpy/ODS/Ge in situ and ex situ were found to be virtually identical, making it possible to isolate by graphical means the most prominent band of py(co) centered at about 1615 cm(-l) for HDpy/ODS/Ge collected in situ. The resulting bands for pure py(co) and pyun in situ were then used to deconvolute spectra recorded in situ for HPpy/ODS/Ge in contact with Cd2+containing solutions in the range 10 nM < [Cd2+] < 0.1 mM, from which information regarding the adsorption isotherm was obtained.[on SciFinder (R)]
Various aspects of the adsorption of Cd2+ on self-assembled monolayers (SAMs) of 4-heptadecylpyridine (HDpy) and 4'-tridecyl-4-Me-2,2'-bipyridine (TMbipy) supported on an octadecylsilane (ODS)-modified Ge prism were examd. both ex situ (dry) and in situ (in the presence of aq. solns.) using attenuated total reflection FTIR spectroscopy. In direct analogy with the behavior found for a variety of genuine pyridine (py) and bipyridine (bipy) metal ion complexes, Cd2+ binding to both SAMs led to shifts in the skeletal vibrational modes of the corresponding uncoordinated ligands in the region 1650-1400 cm-1, toward higher energies. Anal. of spectra acquired ex situ for HDpy/ODS/Ge and TMbipy/ODS/Ge before and after exposure to 0.1 mM [Cd2+] yielded values for the fraction of uncoordinated py, θ(pyun), and uncoordinated bipy, θ(bipyun), of ∼0.5 and ∼0.1, resp. The features attributed to the pyun groups for spectra collected for HDpy/ODS/Ge in situ and ex situ are virtually identical, making it possible to isolate by graphical means the most prominent band of pyco centered at ∼1615 cm-1 for HDpy/ODS/Ge collected in situ. The resulting bands for pure pyco and pyun in situ were then used to deconvolute spectra recorded in situ for HPpy/ODS/Ge in contact with Cd2+-contg. solns. in the range 10 nM < [Cd2+] < 0.1 mM, from which information regarding the adsorption isotherm was obtained. [on SciFinder(R)]
The effect of including vs. excluding diffuse functions while calculating numerous parameters of PAH anions by various calculation methods is discussed. The omission of diffuse functions. appears to have a negligible effect while calculating geometry parameters or total energy; thus, acceptable results may be obtained without them. The conclusions for charge density appear to be the same; however, limited results make an unambiguous claim unachievable. Calculating H-1- and C-13-NMR shifts undoubtedly requires the use of these functions.
Epidermal growth factor receptor (EGFR) controls cell growth and has a key role in tumorigenic processes. The extent of EGFR signaling is tightly regulated by post-transcriptional modifications leading to down-regulation of the levels of the receptor. Previous studies from our laboratory demonstrated that the reactive oxidant hydrogen peroxide activates the EGFR, yet, without down-regulation of the receptor levels, which results in prolonged receptor signaling. In the present study we examined the role of the E3 ligase c-Cbl, as a possible link between oxidative stress, EGFR signaling, and tumorigenic responses. First, we ectopically expressed a mutant EGFR (Tyr-1045 --> Phe) in cells lacking endogenous receptor, to determine whether the lack of phosphorylation at this site is the cause for EGFR retention at the membrane under oxidative stress, as we have previously suggested. Our findings suggest that abrogation of tyrosine 1045 phosphorylation alone is not enough to retain the EGFR at the plasma membrane under oxidative stress. Second, through the use of the Src inhibitor PP1, our findings establish EGFR movement out of the early endosomes as the exact location where c-Cbl-mediated ubiquitinylation is essential for EGFR trafficking. Finally, our studies substantiate the findings that c-Cbl-mediated ubiquitinylation is needed for degradation, but not for internalization of the EGFR in both transfection-dependent Chinese hamster ovary cells and transfection-independent A549 lung epithelial cells. These findings only begin to explain the features seen under oxidative stress, but they yield a greater understanding of the role of c-Cbl in EGFR trafficking.
Joseph Yellin and Michal Artzy. 2004. “Ceramic Provenance: NAA.” In The Ma'agan Mikhael Ship: The Recovery of a 2400-Year-Old Merchantman, Final Report , edited by John Tresman, II: Pp. 221-238. Jerusalem: The Israel Exploration Society and the University of Haifa.
There is growing interest in how much a political candidates' media skills, sometimes referred to as 'charisma', are critical to their electoral success and political survival. According to one hypothesis, the effects of media skills might be so strong, that actors who do not posses media skills quickly vanish from the political arena. However, while many believe that media skills are an important aspect of getting elected, few have actually tried to measure their effects. Part of the reluctance no doubt stems from methodological difficulties in measuring them. In this study we look more directly at the media skills that are likely to play an important role in the electoral competition and suggest a new methodology for measuring such skills. Findings are presented that show that media skills can have an important impact on long-term electoral success of Israeli members of the Knesset. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]
The combinatorial invariant and covariant are introduced as practical tools for analysis of conical intersections in molecules. The combinatorial invariant is a quantity depending on adiabatic electronic states taken at discrete nuclear configuration points. It is invariant to the phase choice (gauge) of these states. In the limit that the points trace a loop in nuclear configuration space, the value of the invariant approaches the corresponding Berry phase factor. The Berry phase indicates the presence of an odd or even number of conical intersections on surfaces bounded by these loops. Based on the combinatorial invariant, we develop a computationally simple and efficient method for locating conical intersections. The method is robust due to its use of gauge invariant nature. It does not rely on the landscape of intersecting potential energy surfaces nor does it require the computation of nonadiabatic couplings. We generalize the concept to open paths and combinatorial covariants for higher dimensions obtaining a technique for the construction of the gauge-covariant adiabatic-diabatic transformation matrix. This too does not make use of nonadiabatic couplings. The importance of using gauge-covariant expressions is underlined throughout. These techniques can be readily implemented by standard quantum chemistry codes.
