1,653 research outputs found

    The Importance of Hydration in Wound Healing: Reinvigorating the clinical perspective

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    Balancing skin hydration levels is important as any disruption in skin integrity will result in disturbance of the dermal water balance. The discovery that a moist wound healing environment actively supports the healing response when compared to a dry environment highlights the importance of water and good hydration levels for optimal wound healing. The benefits of “wet” or “hyper-hydrated” wound healing appears to offer benefits that are similar to those offered by moist wound healing over wounds healing in a dry environment. This suggests that the presence of free water itself during wound healing may not be detrimental to healing but that any adverse effects of wound fluid on tissues is more likely related to the biological components contained within chronic wound exudate (e.g. elevated protease levels). Appropriate dressings applied to wounds must be able to absorb not only the exudate but also retain this excess fluid together with its protease solutes while concurrently preventing desiccation. This is particularly important in the case of chronic wounds where peri-wound skin barrier properties are compromised and there is increased permeation across the injured skin barrier. This review discusses the importance of appropriate levels of hydration in skin with a particular focus on the need for optimal hydration levels for effective healing

    Evaluation of synergistic effect between ethyl formate and phosphine for control of three species Aphids in perishable commodity

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    Methyl bromide (MB) as a fumigant for Quarantine and Pre-shipment (QPS) could offer eradication of target pests within shorter fumigation period and without phytotoxicity. Therefore, unlike MB alternatives for soil fumigation, there is no ideally MB alternative fumigant for QPS purpose, particularly for perishable commodities. It is critically important that within shorter fumigation time requires killing all target insect pests and without effect of quality and deliver treated fruit and vegetables to the final consumer. Aphids are pests frequently found in imported and exported fruit and vegetables. Aphids was known as quarantine pest hard to control when conduct short period fumigation with phosphine (PH3) and low dose of ethyl formate (EF). Ethyl formate can lead to highly sorption and phytotoxic damage of some perishable commodities such as strawberries and cut flowers, especially at lower temperature (< 8°C). Here, we reported that synergistic effect between ethyl formate and phosphine at lower dosages and temperature. The mixture of ethyl formate and phosphine had synergistic effect to control adult and nymph stages of tested cotton aphid (Aphis gossypii), green peach aphid (Myzus persicae) and turnip aphid (Lipaphis erysimi). When 0.5 mg/L of PH3 combined with different levels of EF at 5 and 20°C for 2 hours fumigation, there was significantly difference in terms of LCT50% and LCT90% values in comparison with EF or PH3 alone. This new technology could be meet QPS requirement that is shorter exposure time and less damage of perishable commodities

    Wound healing and hyper-hydration - a counter intuitive model

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    Winters seminal work in the 1960s relating to providing an optimal level of moisture to aid wound healing (granulation and re-epithelialisation) has been the single most effective advance in wound care over many decades. As such the development of advanced wound dressings that manage the fluidic wound environment have provided significant benefits in terms of healing to both patient and clinician. Although moist wound healing provides the guiding management principle confusion may arise between what is deemed to be an adequate level of tissue hydration and the risk of developing maceration. In addition, the counter-intuitive model ‘hyper-hydration’ of tissue appears to frustrate the moist wound healing approach and advocate a course of intervention whereby tissue is hydrated beyond what is a normally acceptable therapeutic level. This paper discusses tissue hydration, the cause and effect of maceration and distinguishes these from hyper-hydration of tissue. The rationale is to provide the clinician with a knowledge base that allows optimisation of treatment and outcomes and explains the reasoning behind wound healing using hyper-hydration

    Potential of wind-powered renewable energy membrane systems for Ghana

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    Areas of the world that lack fresh water often have an ample supply of wind or solar energy, making renewable energy an attractive option as a power source for desalination systems. Particularly, wind energy is attractive because of its relatively low cost, high efficiency, and recent technological advancements in this area of research. To open system applicability to a broader range of geographical areas, the feasibility of substituting solar panels with a wind turbine on an existing membrane desalination systemthat has undergone testing in the Australian outback is examined. The use of wind turbines will provide greater scope for the system's implementation in various parts of the world according to the local wind or solar resources.Acomparison of several small wind turbines coupled with wind speed data from Ghana showed that a 1 kW FuturEnergy wind turbine would give the best performance for the lowest cost and is therefore the most appropriate for coupling with the membrane system. The predicted permeate production is 1.3 m3/d at a specific energy consumption (SEC) of 1.8 kWh/m3

    Light scattering observations of spin reversal excitations in the fractional quantum Hall regime

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    Resonant inelastic light scattering experiments access the low lying excitations of electron liquids in the fractional quantum Hall regime in the range 2/5≄Μ≄1/32/5 \geq \nu \geq 1/3. Modes associated with changes in the charge and spin degrees of freedom are measured. Spectra of spin reversed excitations at filling factor Îœâ‰ł1/3\nu \gtrsim 1/3 and at Îœâ‰Č2/5\nu \lesssim 2/5 identify a structure of lowest spin-split Landau levels of composite fermions that is similar to that of electrons. Observations of spin wave excitations enable determinations of energies required to reverse spin. The spin reversal energies obtained from the spectra illustrate the significant residual interactions of composite fermions. At Îœ=1/3\nu = 1/3 energies of spin reversal modes are larger but relatively close to spin conserving excitations that are linked to activated transport. Predictions of composite fermion theory are in good quantitative agreement with experimental results.Comment: Submitted to special issue of Solid State Com

    Transport and the Order Parameter of Superconducting UPt3

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    We calculate the ultrasonic absorption and the thermal conductivity in the superconducting state of UPt3_{3} as functions of temperature and direction of propagation and polarization. Two leading candidates for the superconducting order parameter are considered: the E1gE_{1g} and E2uE_{2u} representations. Both can fit the data except for the ultrasonic absorption in the AA phase. To do that, it is necessary to suppose that the system has only a single domain, and that must be chosen as the most favorable one. However, the E2uE_{2u} theory requires fine-tuning of parameters to fit the low temperature thermal conductivity. Thus, transport data favor the E1gE_{1g} theory. Measurements of the thermal conductivity as a function of pressure at low temperature could help to further distinguish the two theories.Comment: 7 pages, 4 figure

    Phase Transition in Conformally Induced Gravity with Torsion

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    We have considered the quantum behavior of a conformally induced gravity in the minimal Riemann-Cartan space. The regularized one-loop effective potential considering the quantum fluctuations of the dilaton and the torsion fields in the Coleman-Weinberg sector gives a sensible phase transition for an inflationary phase in De Sitter space. For this effective potential, we have analyzed the semi-classical equation of motion of the dilaton field in the slow-rolling regime.Comment: 7pages, no figur

    Weak Localization Effect in Superconductors by Radiation Damage

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    Large reductions of the superconducting transition temperature TcT_{c} and the accompanying loss of the thermal electrical resistivity (electron-phonon interaction) due to radiation damage have been observed for several A15 compounds, Chevrel phase and Ternary superconductors, and NbSe2\rm{NbSe_{2}} in the high fluence regime. We examine these behaviors based on the recent theory of weak localization effect in superconductors. We find a good fitting to the experimental data. In particular, weak localization correction to the phonon-mediated interaction is derived from the density correlation function. It is shown that weak localization has a strong influence on both the phonon-mediated interaction and the electron-phonon interaction, which leads to the universal correlation of TcT_{c} and resistance ratio.Comment: 16 pages plus 3 figures, revtex, 76 references, For more information, Plesse see http://www.fen.bilkent.edu.tr/~yjki

    Instanton Induced Neutrino Majorana Masses in CFT Orientifolds with MSSM-like spectra

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    Recently it has been shown that string instanton effects may give rise to neutrino Majorana masses in certain classes of semi-realistic string compactifications. In this paper we make a systematic search for supersymmetric MSSM-like Type II Gepner orientifold constructions admitting boundary states associated with instantons giving rise to neutrino Majorana masses and other L- and/or B-violating operators. We analyze the zero mode structure of D-brane instantons on general type II orientifold compactifications, and show that only instantons with O(1) symmetry can have just the two zero modes required to contribute to the 4d superpotential. We however discuss how the addition of fluxes and/or possible non-perturbative extensions of the orientifold compactifications would allow also instantons with Sp(2)Sp(2) and U(1) symmetries to generate such superpotentials. In the context of Gepner orientifolds with MSSM-like spectra, we find no models with O(1) instantons with just the required zero modes to generate a neutrino mass superpotential. On the other hand we find a number of models in one particular orientifold of the Gepner model (2,4,22,22)(2,4,22,22) with Sp(2)Sp(2) instantons with a few extra uncharged non-chiral zero modes which could be easily lifted by the mentioned effects. A few more orientifold examples are also found under less stringent constraints on the zero modes. This class of Sp(2)Sp(2) instantons have the interesting property that R-parity conservation is automatic and the flavour structure of the neutrino Majorana mass matrices has a simple factorized form.Comment: 68 pages, 2 figures; v2. typos corrected, refs adde
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