Composition of eye cosmetics (kohls) used in Cairo

A total of 18 kohl samples were analysed using X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM). All the samples were purchased in Cairo and eleven of them originated in Egypt. The main component of six samples was found to be galena (PbS); where four of these samples originated in Egypt and two in India. For a further ten samples the main component was found to be one of the following: amorphous carbon, calcite (CaCO3), cuprite (Cu2O), goethite (FeO(OH)), elemental silicon or talc (Mg3Si4O10(OH)2). For the last two samples the main component of each was an unknown amorphous organic compound

Interactions of short-term and chronic treadmill training with aging of the left ventricle of the heart

With aging, there is a decline in cardiac function accompanying increasing risk of arrhythmias. These effects are likely to be mechanistically associated with age-associated changes in calcium regulation within cardiac myocytes. Previous studies suggest that lifelong exercise can potentially reduce age-associated changes in the heart. Although exercise itself is associated with changes in cardiac function, little is known about the interactions of aging and exercise with respect to myocyte calcium regulation. To investigate this, adult (12 months) and old (24 months) C57/Bl6 mice were trained using moderate-intensity treadmill running. In response to 10 weeks’ training, comparable cardiac hypertrophic responses were observed, although aging independently associated with additional cardiac hypertrophy. Old animals also showed increased L- and T-type calcium channels, the sodium–calcium exchange, sarcoendoplasmic reticulum calcium ATPase, and collagen (by 50%, 92%, 66%, 88%, and 113% respectively). Short-term exercise training increased D-type and T-type calcium channels in old animals only, whereas an increase in sodium–calcium exchange was seen only in adult animals. Long-term (12 months) training generally opposed the effects of aging. Significant hypertrophy remained in long-term trained old animals, but levels of sarcoendoplasmic reticulum calcium ATPase, sodium–calcium exchange, and collagen were not significantly different from those found in the adult trained animals

K2p3.1 protein is expressed as a transmural gradient across the rat left ventricular free wall

Introduction: K 2p 3.1, also known as TASK-1, is a twin-pore acid-sensitive repolarizing K + channel, responsible for a background potassium current that significantly contributes to setting the resting membrane potential of cardiac myocytes. Inhibition of I K2p3.1 alters cardiac repolarization and is proarrhythmogenic. In this study, we have examined the expression of K 2p 3.1 and function of this channel in tissue and myocytes from across the left ventricular free wall. Methods and Results: Using fluorescence immunocytochemistry, the expression of K 2p 3.1 protein in myocytes from the subendocardial region was found to be twice (205% ± 13.5%) that found in myocytes from the subepicardial region of the left ventricle (100% ± 5.3%). The left ventricular free wall exhibited a marked transmural gradient of K 2p 3.1 protein expression. Western blot analysis confirmed significantly higher K 2p 3.1 protein expression in subendocardial tissue (156% ± 2.5%) than subepicardial tissue (100% ± 5.0%). However, there was no difference in K 2p 3.1 messenger RNA expression. Whole-cell patch clamp identified I K2p3.1 current density to be significantly greater in myocytes isolated from the subendocardium (7.66 ± 0.53 pA/pF) compared with those from the subepicardium (3.47 ± 0.74 pA/pF). Conclusions: This is the first study to identify a transmural gradient of K 2p 3.1 in the left ventricle. This gradient has implications for understanding ventricular arrhythmogenesis under conditions of ischemia but also in response to other modulatory factors, such as adrenergic stimulation and the presence of anesthetics that inhibits or activates this channel

The Mississippi River System Shallow Draft Barge Market – Perfectly Competitive or Oligopolistic?

Most transportation textbooks and articles on inland waterway navigation assume a perfectly competitive Mississippi River system barge industry. One study found the 1972 and 1977 grain barge industry to be oligopolistic. A second study of the U.S. barge industry found "intra industry competition for the barge industry on a day-to-day basis with easy entry and exit." Using the concentration ratio and the Herfindahl Index, this study found the Mississippi River barge industry to be oligopolistic. These results suggest that Mississippi River navigation infrastructure studies should not use long run marginal barge costs as a proxy for barge rates

Etching with Electron Beam Generated Plasmas

A modulated electron beam generated plasma has been used to dry etch standard photoresist materials and silicon. Oxygen–argon mixtures were used to etch organic resist material and sulfur hexafluoride mixed with argon or oxygen was used for the silicon etching. Etch rates and anisotropy were determined with respect to gas compositions, incident ion energy (from an applied rf bias) and plasma duty factor. For 1818 negative resist and i-line resists the removal rate increased nearly linearly with ion energy (up to 220 nm/min at 100 eV), with reasonable anisotropic pattern transfer above 50 eV. Little change in etch rate was seen as gas composition went from pure oxygen to 70% argon, implying the resist removal mechanism in this system required the additional energy supplied by the ions. With silicon substrates at room temperature, mixtures of argon and sulfur hexafluoride etched approximately seven times faster (1375 nm/min) than mixtures of oxygen and sulfur hexafluoride (,200 nm/min) with 200 eV ions, the difference is attributed to the passivation of the silicon by involatile silicon oxyfluoride sSiOxFyd compounds. At low incident ion energies, the Ar–SF6 mixtures showed a strong chemical (lateral) etch component before an ion-assisted regime, which started at ,75 eV. Etch rates were independent of the 0.5%–50% duty factors studied in this work

Etching with Electron Beam Generated Plasmas

A modulated electron beam generated plasma has been used to dry etch standard photoresist materials and silicon. Oxygen–argon mixtures were used to etch organic resist material and sulfur hexafluoride mixed with argon or oxygen was used for the silicon etching. Etch rates and anisotropy were determined with respect to gas compositions, incident ion energy (from an applied rf bias) and plasma duty factor. For 1818 negative resist and i-line resists the removal rate increased nearly linearly with ion energy (up to 220 nm/min at 100 eV), with reasonable anisotropic pattern transfer above 50 eV. Little change in etch rate was seen as gas composition went from pure oxygen to 70% argon, implying the resist removal mechanism in this system required the additional energy supplied by the ions. With silicon substrates at room temperature, mixtures of argon and sulfur hexafluoride etched approximately seven times faster (1375 nm/min) than mixtures of oxygen and sulfur hexafluoride (,200 nm/min) with 200 eV ions, the difference is attributed to the passivation of the silicon by involatile silicon oxyfluoride sSiOxFyd compounds. At low incident ion energies, the Ar–SF6 mixtures showed a strong chemical (lateral) etch component before an ion-assisted regime, which started at ,75 eV. Etch rates were independent of the 0.5%–50% duty factors studied in this work

Effect of Plasma Flux Composition on the Nitriding Rate of Stainless Steel

The total ion flux and nitriding rate for stainless steel specimens exposed to a modulated electron beam generated argon-nitrogen plasma were measured as a function of distance from the electron beam axis. The total ion flux decreased linearly with distance, but the nitriding rate increased under certain conditions, contrary to other ion flux/nitriding rate comparisons published in the literature. Variation in ion flux composition with distance was explored with a mass spectrometer and energy analyzer as a possible explanation for the anomalous nitriding rate response to ion flux magnitude. A transition in ion flux composition from mostly N2 1 to predominantly N1 ions with increasing distance was observed. Significant differences in molecular and atomic nitrogen ion energy distributions at a negatively biased electrode were also measured. An explanation for nitriding rate dependence based on flux composition and magnitude is proposed