Oscillations at the Si/electrolyte contact: Relation to Quantum Mechanics

The basic process at the surface of the Si electrode is characterized by a cyclic oxidation of a thin silicon layer and the subsequent removal of the oxide by etching. Here, the oxide thickness evolves not uniformly due to cracks and nanopores. The mathematical model used to describe the phenomenon is based on a sequence of time dependent (oxide thickness) oscillator density functions that describes the passing of the (infinitesimal) oscillators through their minimum at each cycle. Two consecutive oscillator density functions are connected by a second order linear integral equation representing a Markov process. The kernel of the integral equation is a normalized Greens Function and represents the probability distribution for the periods of the oscillators during a cycle. Both, the oscillator density function and the two-dimensional probability density for the periods of the oscillators, define a random walk. A relation between the oscillator density functions and solutions of the Fokker-Planck equation can be constructed. This allows a connection of the oscillations, originally considered only for the description of a photo-electrochemical observation, to the Schrodinger equation. In addition, if the trajectory of a virtual particle, located at the silicon oxide electrode surface, is considered during one oscillatory cycle, then it can be shown that the displacement of the particle measured at the electrode surface performs a Brownian motion

Ginger extract inhibits LPS induced macrophage activation and function

<p>Abstract</p> <p>Background</p> <p>Macrophages play a dual role in host defence. They act as the first line of defence by mounting an inflammatory response to antigen exposure and also act as antigen presenting cells and initiate the adaptive immune response. They are also the primary infiltrating cells at the site of inflammation. Inhibition of macrophage activation is one of the possible approaches towards modulating inflammation. Both conventional and alternative approaches are being studied in this regard. Ginger, an herbal product with broad anti inflammatory actions, is used as an alternative medicine in a number of inflammatory conditions like rheumatic disorders. In the present study we examined the effect of ginger extract on macrophage activation in the presence of LPS stimulation.</p> <p>Methods</p> <p>Murine peritoneal macrophages were stimulated by LPS in presence or absence of ginger extract and production of proinflammatory cytokines and chemokines were observed. We also studied the effect of ginger extract on the LPS induced expression of MHC II, B7.1, B7.2 and CD40 molecules. We also studied the antigen presenting function of ginger extract treated macrophages by primary mixed lymphocyte reaction.</p> <p>Results</p> <p>We observed that ginger extract inhibited IL-12, TNF-α, IL-1β (pro inflammatory cytokines) and RANTES, MCP-1 (pro inflammatory chemokines) production in LPS stimulated macrophages. Ginger extract also down regulated the expression of B7.1, B7.2 and MHC class II molecules. In addition ginger extract negatively affected the antigen presenting function of macrophages and we observed a significant reduction in T cell proliferation in response to allostimulation, when ginger extract treated macrophages were used as APCs. A significant decrease in IFN-γ and IL-2 production by T cells in response to allostimulation was also observed.</p> <p>Conclusion</p> <p>In conclusion ginger extract inhibits macrophage activation and APC function and indirectly inhibits T cell activation.</p

Ginger inhibits cell growth and modulates angiogenic factors in ovarian cancer cells

<p>Abstract</p> <p>Background</p> <p>Ginger (<it>Zingiber officinale </it>Rosc) is a natural dietary component with antioxidant and anticarcinogenic properties. The ginger component [6]-gingerol has been shown to exert anti-inflammatory effects through mediation of NF-κB. NF-κB can be constitutively activated in epithelial ovarian cancer cells and may contribute towards increased transcription and translation of angiogenic factors. In the present study, we investigated the effect of ginger on tumor cell growth and modulation of angiogenic factors in ovarian cancer cells <it>in vitro</it>.</p> <p>Methods</p> <p>The effect of ginger and the major ginger components on cell growth was determined in a panel of epithelial ovarian cancer cell lines. Activation of NF-κB and and production of VEGF and IL-8 was determined in the presence or absence of ginger.</p> <p>Results</p> <p>Ginger treatment of cultured ovarian cancer cells induced profound growth inhibition in all cell lines tested. We found that <it>in vitro</it>, 6-shogaol is the most active of the individual ginger components tested. Ginger treatment resulted in inhibition of NF-kB activation as well as diminished secretion of VEGF and IL-8.</p> <p>Conclusion</p> <p>Ginger inhibits growth and modulates secretion of angiogenic factors in ovarian cancer cells. The use of dietary agents such as ginger may have potential in the treatment and prevention of ovarian cancer.</p

Chemical stability of CuInS2 in oxygen at 298 K

A thermochemical analysis is performed in the quaternary system Cu In S O at 298 K, including the respective four ternaries. The Cu In phase diagram is updated with respect to the new experimental as well as to the new thermochemical results in the literature. Free energies of In6S7, In2.8S4, CuIn2, and Cu2In2O5 have been estimated. Consistent sets of data are used for the calculations of the ternary systems with the program THERMO, and the results are used to calculate the quaternary tetrahedron Cu In S O with the program THERMOQ; the algorithm is given. Twelve quaternary two phase equilibria have been found. They are used to calculate predominance area diagrams of the quaternary system with the program STADIAQ for different oxygen partial pressures. The algorithm of this program is given. From these diagrams it becomes obvious that CuInS2 is unstable in air and even in UHV systems and should react to form In 2 SO4 3 and Cu2S at oxygen pressures larger than log p pascal 51.5. The results are useful for research in fields such as oxidation and crystal growth of CuInS2 and for development of processes for producing this compoun