Ginzburg - Landau equation from SU(2) gauge field theory

The dual superconductor picture of the QCD vacuum is thought to describe various aspects of the strong interaction including confinement. Ordinary superconductivity is described by the Ginzburg-Landau (GL) equation. In the present work we show that it is possible to arrive at a GL-like equation from pure SU(2) gauge theory. This is accomplished by using Abelian projection to split the SU(2) gauge fields into an Abelian subgroup and its coset. The two gauge field components of the coset part act as the effective, complex, scalar field of the GL equation. The Abelian part of the SU(2) gauge field is then analogous to the electromagnetic potential in the GL equation. An important aspect of the dual superconducting model is for the GL Lagrangian to have a spontaneous symmetry breaking potential, and the existence of Nielsen-Olesen flux tube solutions. Both of these require a tachyonic mass for the effective scalar field. Such a tachyonic mass term is obtained from the condensation of ghost fields.Comment: 7 pages, LATE

Orientation dependent molecular electrostatics drives efficient charge generation in homojunction organic solar cells

Organic solar cells usually utilise a heterojunction between electron-donating (D) and electron-accepting (A) materials to split excitons into charges. However, the use of D-A blends intrinsically limits the photovoltage and introduces morphological instability. Here, we demonstrate that polycrystalline films of chemically identical molecules offer a promising alternative and show that photoexcitation of α-sexithiophene (α-6T) films results in efficient charge generation. This leads to α-6T based homojunction organic solar cells with an external quantum efficiency reaching up to 44% and an open-circuit voltage of 1.61 V. Morphological, photoemission, and modelling studies show that boundaries between α-6T crystalline domains with different orientations generate an electrostatic landscape with an interfacial energy offset of 0.4 eV, which promotes the formation of hybridised exciton/charge-transfer states at the interface, dissociating efficiently into free charges. Our findings open new avenues for organic solar cell design where material energetics are tuned through molecular electrostatic engineering and mesoscale structural control

Spectroscopic studies on the anticancer antibiotic Altromycin H and the interaction with copper(II) ions

The antitumor antibiotic Altromycin H was studied using electronic absorption (UV-Vis.) and circular dichroism (CD) spectroscopy. The dissociation constants of the phenolic groups on C(5) and C(11) were estimated as pK 1 = 6.7 and pK 2 = 11.8 at 25°C, respectively, and a complete assignment of the CD and UV-Vis. bands is proposed. The interaction of Cu(II) ions with the Altromycin H has been also investigated by UV-Vis., CD and electron paramagnetic resonance (EPR) spectroscopy. A pH depended stepwise complex formation was observed. At pH < 4 no copper-Altromycin H interactions were detected. At the 4 < pH < 8 the Cu(II) ions coordinate to Altromycin H via the C(4)O and C(5)OH groups atoms of the chromophore ring and the [Cu(AltroH) 2] complex (formation constant, K f, 4.00 ± 0.9 × 10 11 M -2 at 25°C) is the predominant species. In alkaline solution the hydroxo-bridged complex, [Cu(OH)(AltroH)] 2, is proposed to be as the unique present species. © 2004 Elsevier Inc. All rights reserved

Interactions of the anticancer antibiotic altromycin B with copper(II), palladium(II) and platinum(II) ions and in vitro activity of the formed complexes

Interaction of the anticancer antibiotic altromycin B with Cu(II), Pd(II) and Pt(II) ions was studied using 1H-NMR, EPR, electronic absorption and circular dichroism spectroscopy. The results derived from NMR studies where that the Pt(II) and Pd(II) ions interact with the nitrogen atom of the dimethylamino group of the C(10)-disaccharide, while the C(2)-epoxide group does not participate and remains intact. Cu(II) ions interact in a different way with altromycin B as was concluded by EPR and circular dichroism spectra. Altromycin B coordinates to the Cu(II) ions via the oxygen atoms of the C(11) phenolic and the C(12) carbonyl group while the nitrogen atom does not participate in the complexation. The presence of these metal ions improves the stability of altromycin B in solution. These complexes were studied in vitro against K562 leukemia sensitive and doxorubicin-resistant cells and GLC4 lung tumor cells, sensitive and doxorubicin-resistant. The activity of the complexes compared to the free drug is improved against resistant cells and is affected moderately against sensitive cells. Finally, 20% of platinum added as altromycin B metal complex entered GLC4 cells. Copyright © 2001 Elsevier Science Inc

A prospective case series evaluating the safety and efficacy of the Klox BioPhotonic System in venous leg ulcers

Andreas Nikolis,1 Doria Grimard,2 Yves Pesant,3 Giovanni Scapagnini,4 Denis Vézina5 1Division of Plastic Surgery, Victoria Park Research Centre, Montreal, 2Q&T Research Chicoutimi, Chicoutimi, 3St-Jerome Medical Research Inc., St-Jerome, Quebec, Canada; 4Department of Medicine and Health Sciences, School of Medicine, University of Molise, Campobasso, Italy; 5Klox Technologies, Laval, Quebec, Canada Purpose: To investigate the safety and efficacy of the BioPhotonic System developed by Klox Technologies in a case series of ten patients with venous leg ulcers.Patients and methods: Ten patients with chronic venous leg ulcers, having failed on at least one previous therapy, were enrolled into this case series.Results: Nine patients were evaluable for efficacy. A response (defined as decrease in wound surface area) was observed in seven patients (77.8%). Of these, four patients (44.4%) achieved wound closure on average 4 months (127.5 days) following the beginning of the treatment. Two patients did not respond to the investigational treatment. Quality of life improved over time throughout the study. Compliance was excellent, with 93.2% of visits completed as per protocol. Safety was unremarkable, with only four treatment-emergent-related adverse events, for which no specific intervention was required.Conclusion: The BioPhotonic System was shown to be safe and extremely well tolerated. It also demonstrated potential in terms of wound closure, wound surface area decrease, and wound bed preparation. Keywords: biophotonics, light, photobiomodulation, venous leg ulcer

Biogeochemistry of lead in an urban forest in Athens, Greece

The distribution and cycling of lead (Pb) was examined in an urban forest of Aleppo pine stand in Athens. Concentrations of the soluble fraction of Pb in bulk and throughfall deposition were low, reflectingthe change in petrol form in recent years. However, Pb concentrations in forest floor remain high due to Pb accumulation in previous years. The soil A horizon showed unexpectedly high levels of Pb concentration resulted probably from Pb migration from organic horizons. Pb concentrations in pine needles, litterfall and wood were low, whereas tree bark acted as a sink for Pb and stored high amounts of the metal. © Springer 2005

Biogeochemistry of lead in an urban forest in Athens, Greece

The distribution and cycling of lead (Pb) was examined in an urban forest of Aleppo pine stand in Athens. Concentrations of the soluble fraction of Pb in bulk and throughfall deposition were low, reflectingthe change in petrol form in recent years. However, Pb concentrations in forest floor remain high due to Pb accumulation in previous years. The soil A horizon showed unexpectedly high levels of Pb concentration resulted probably from Pb migration from organic horizons. Pb concentrations in pine needles, litterfall and wood were low, whereas tree bark acted as a sink for Pb and stored high amounts of the metal. © Springer 2005