Enhanced chlorhexidine skin penetration with eucalyptus oil

Background Chlorhexidine digluconate (CHG) is a widely used skin antiseptic, however it poorly penetrates the skin, limiting its efficacy against microorganisms residing beneath the surface layers of skin. The aim of the current study was to improve the delivery of chlorhexidine digluconate (CHG) when used as a skin antiseptic. Method Chlorhexidine was applied to the surface of donor skin and its penetration and retention under different conditions was evaluated. Skin penetration studies were performed on full-thickness donor human skin using a Franz diffusion cell system. Skin was exposed to 2% (w/v) CHG in various concentrations of eucalyptus oil (EO) and 70% (v/v) isopropyl alcohol (IPA). The concentration of CHG (µg/mg of skin) was determined to a skin depth of 1500 µm by high performance liquid chromatography (HPLC). Results The 2% (w/v) CHG penetration into the lower layers of skin was significantly enhanced in the presence of EO. Ten percent (v/v) EO in combination with 2% (w/v) CHG in 70% (v/v) IPA significantly increased the amount of CHG which penetrated into the skin within 2 min. Conclusion The delivery of CHG into the epidermis and dermis can be enhanced by combination with EO, which in turn may improve biocide.

Studies of skin antisepsis and enhanced penetration of chlorhexidine

Current evidence-based guidelines recommend that 2% (w/v) chlorhexidine digluconate (CHG), preferentially in 70% (v/v) isopropyl alcohol (IIPA), is used for skin antisepsis prior to incision of the skin. In this current study, the antimicrobial efficacy of CHG, six essential oils [tea tree oil (TTO), thymol, eucalyptus oil (EO), juniper oil, lavender oil and citronella] and novel benzylidenecarboxamidrazone and thiosemicarbazone compounds were determined against a panel of microorganisms commonly associated with skin infection (Staphylococcus epidermidis, S. aureus, meticillin-resistant S. aureus, Propionibacterium acnes, Acinetobacter spp., Pseudomonas aeruginosa and Candida albicans) The results demonstrated synergistic activity of CHG in combination with EO against biofilm cultures of S. epidermidis, with significantly reduced concentrations of CHG and EO required to inhibit biofilm growth compared to CHG or EO alone. Skin permeation of CHG was subsequently investigated using an in vitro human skin model (Franz cell) and the penetration profile was determined by serial sectioning of the full thickness human skin. Two percent (w/v) CHG in aqueous solution and in 70% (v/v) IPA demonstrated poor skin permeation; however, the skin permeation was significantly enhanced in combination with 5% - 50% (v/v) EO. Detectable levels of CHG did not permeate through full thickness skin in 24 h. Skin permeation of 2% (w/v) CHG in 70% (v/v) IPA in the presence of 10% (v/v) EO was subsequently studied. The results demonstrated a significantly enhanced skin penetration of CHG after a 2 min application, with CHG detected at significant levels to a depth of 600 m with CHG in combination with EO and IPA compared to 100 m with IPA alone. Combination antisepsis comprising CHG and EO may be beneficial for skin antisepsis prior to invasive procedures to reduce the number of microorganisms on and within the skin due to enhanced skin penetration of CHG and improved efficacy against S. epidermidis in a biofilm mode of growth.

(Table 1) Basement penetration, recovery, and lithology of crustal DSDP holes in the North Atlantic Ocean

Oceanic crustal drilling by R. V. Glomar Challenger at 15 sites in the North Atlantic has led to a complex picture of the upper half kilometer of the crust. Elements of the picture include the absence of the source for linear magnetic anomalies, marked episodicity of volcanic activity, ubiquitous low temperature alteration and evidence for large scale tectonic disturbance. Comparison sections in the Pacific and much deeper crustal drilling are needed to attack problems arising from the North Atlantic results.

Cone penetration testing to assess slope stability in the 1979 Nice landslide area (Ligurian Margin, SE France)

In the landslide-prone area near the Nice international airport, southeastern France, an interdisciplinary approach is applied to develop realistic lithological/geometrical profiles and geotechnical/strength sub-seafloor models. Such models are indispensable for slope stability assessments using limit equilibrium or finite element methods. Regression analyses, based on the undrained shear strength (su) of intact gassy sediments are used to generate a sub-seafloor strength model based on 37 short dynamic and eight long static piezocone penetration tests, and laboratory experiments on one Calypso piston and 10 gravity cores. Significant strength variations were detected when comparing measurements from the shelf and the shelf break, with a significant drop in su to 5.5 kPa being interpreted as a weak zone at a depth between 6.5 and 8.5 m below seafloor (mbsf). Here, a 10% reduction of the in situ total unit weight compared to the surrounding sediments is found to coincide with coarse-grained layers that turn into a weak zone and detachment plane for former and present-day gravitational, retrogressive slide events, as seen in 2D chirp profiles. The combination of high-resolution chirp profiles and comprehensive geotechnical information allows us to compute enhanced 2D finite element slope stability analysis with undrained sediment response compared to previous 2D numerical and 3D limit equilibrium assessments. Those models suggest that significant portions (detachment planes at 20 m or even 55 mbsf) of the Quaternary delta and slope apron deposits may be mobilized. Given that factors of safety are equal or less than 1 when further considering the effect of free gas, a high risk for a landslide event of considerable size off Nice international airport is identified

Intraseasonal variability of mixed layer depth in the tropical Indian Ocean

In this paper, we use an observational dataset built from Argo in situ profiles to describe the main large-scale patterns of intraseasonal mixed layer depth (MLD) variations in the Indian Ocean. An eddy permitting (0.25A degrees) regional ocean model that generally agrees well with those observed estimates is then used to investigate the mechanisms that drive MLD intraseasonal variations and to assess their potential impact on the related SST response. During summer, intraseasonal MLD variations in the Bay of Bengal and eastern equatorial Indian Ocean primarily respond to active/break convective phases of the summer monsoon. In the southern Arabian Sea, summer MLD variations are largely driven by seemingly-independent intraseasonal fluctuations of the Findlater jet intensity. During winter, the Madden-Julian Oscillation drives most of the intraseasonal MLD variability in the eastern equatorial Indian Ocean. Large winter MLD signals in northern Arabian Sea can, on the other hand, be related to advection of continental temperature anomalies from the northern end of the basin. In all the aforementioned regions, peak-to-peak MLD variations usually reach 10 m, but can exceed 20 m for the largest events. Buoyancy flux and wind stirring contribute to intraseasonal MLD fluctuations in roughly equal proportions, except for the Northern Arabian Sea in winter, where buoyancy fluxes dominate. A simple slab ocean analysis finally suggests that the impact of these MLD fluctuations on intraseasonal sea surface temperature variability is probably rather weak, because of the compensating effects of thermal capacity and sunlight penetration: a thin mixed-layer is more efficiently warmed at the surface by heat fluxes but loses more solar flux through its lower base.

Variabilidade espacial de atributos físicos de um argissolo vermelho-amarelo sob pastagem e vegetação secundária em regeneração natural

This work was carried out with the objective of studying the spatial variability of the physical attributes of a Red-Yellow Ultisol under pasture and secondary vegetation in natural regeneration. Two areas were chosen in a hillside, with the soil sampling to the depth of 0-0.2 m, with the georeferenced points in a regular grid of 10x10 m, totalizing 64 points. In each point it was evaluated the total volume of porosity, macroporosity, microporosity, bulk density, soil penetration resistance and soil water content. The studied attributes in the pasture area present indicator of soil compaction for the animals' traffic, with moderate and strong structure of spatial dependence, except for the macroporosity and penetration resistance. In the area of secondary vegetation (VN) only the macroporosity does not present spatial dependence. The total volume of porosity and the bulk density present the same spatial standard in the area under pasture.

Multifilter rotating shadowband radiometer calibration for spectral aerosol optical depth retrievals over Sao Paulo City, Brazil

Multifilter rotating shadowband radiometer (MFRSR) calibration values for aerosol optical depth (AOD) retrievals were determined by means of the general method formulated by Forgan [Appl. Opt. 33, 4841 (1994)] at a polluted urban site. The obtained precision is comparable with the classical method, the Langley plot, applied on clean mountaintops distant of pollution sources. The AOD retrieved over Sao Paulo City with both calibration procedures is compared with the Aerosol Robotic Network data. The observed results are similar, and, except for the shortest wavelength (415 nm), the MFRSR`s AOD is systematically overestimated by similar to 0.03. (c) 2008 Optical Society of America.

Depth-dependent local structures in thin films unraveled by grazing-incidence X-ray absorption spectroscopy

A method of using X-ray absorption spectroscopy together with resolved grazing-incidence geometry for depth profiling of atomic, electronic or chemical local structures in thin films is presented. The quantitative deconvolution of thickness-dependent spectral features is performed by fully considering both scattering and absorption formalisms. Surface oxidation and local structural depth profiles in nanometric FePt films are determined, exemplifying the application of the method.

Measurement of the depth of maximum of extensive air showers above 10(18) eV

We describe the measurement of the depth of maximum, X(max), of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10(18) eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +/- 35-21) g/cm(2)/decade below 10(18.24) +/- (0.05) eV, and d24 +/- 3 g/cm(2)/ecade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm(2). The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

Anthropogenic carbon distribution in the eastern South Pacific Ocean

We present results of the CO(2)/carbonate system from the BIOSOPE cruise in the Eastern South Pacific Ocean, in an area not sampled previously. In particular, we present estimates of the anthropogenic carbon (C(ant)(TrOCA)) distribution in the upper 1000m of this region using the TrOCA method. The highest concentrations of C(ant)(TrOCA) found around 13 degrees S, 132 degrees W and 32 degrees S, 91 degrees W, are higher than 80 mu mol.kg(-)1 and 70 mu mol.kg(-1), respectively. The lowest concentrations are observed below 800m depth (<= 2 mu mol.kg(-1)) and within the Oxygen Minimum Zone (OMZ), mainly around 140 degrees W (< 11 mu mol.kg(-1)). As a result of the anthropogenic carbon penetration there has been decrease in pH by over 0.1 on an average in the upper 200 m. This work further improves our understanding on the penetration of anthropogenic carbon in the Eastern Pacific Ocean.

Node-Depth Encoding and Multiobjective Evolutionary Algorithm Applied to Large-Scale Distribution System Reconfiguration

The power loss reduction in distribution systems (DSs) is a nonlinear and multiobjective problem. Service restoration in DSs is even computationally hard since it additionally requires a solution in real-time. Both DS problems are computationally complex. For large-scale networks, the usual problem formulation has thousands of constraint equations. The node-depth encoding (NDE) enables a modeling of DSs problems that eliminates several constraint equations from the usual formulation, making the problem solution simpler. On the other hand, a multiobjective evolutionary algorithm (EA) based on subpopulation tables adequately models several objectives and constraints, enabling a better exploration of the search space. The combination of the multiobjective EA with NDE (MEAN) results in the proposed approach for solving DSs problems for large-scale networks. Simulation results have shown the MEAN is able to find adequate restoration plans for a real DS with 3860 buses and 632 switches in a running time of 0.68 s. Moreover, the MEAN has shown a sublinear running time in function of the system size. Tests with networks ranging from 632 to 5166 switches indicate that the MEAN can find network configurations corresponding to a power loss reduction of 27.64% for very large networks requiring relatively low running time.

Efficacy of surface hydrophobic agents in reducing water and chloride ion penetration in concrete

Hydrophobic agents are surface protection materials capable of increasing the angle of contact between the water and the concrete surface. For this reason, hydrophobic agents reduce water (in liquid form) penetration in concrete. Therefore, many European construction regulating agencies recommend this treatment in their maintenance policy. Nonetheless, there continues to be a gap in the understanding about which transport mechanisms of the concrete are modified by the hidrophobic agents. The aim of this study was to fill this gap in regards to reinforced concrete structures inserted in a marine environment. To this end, certain tests were used: Two involving permeability mechanism, one determining capillary absorption, and the last, a migration test used to estimate the chloride diffusion coefficient in saturated condition. Results indicated the efficacy of the hydrophobic agents in cases where capillary suction is the mechanism of water penetration (reduced by 2.12 and 7.0 times, depending of the product). However, when the transport mechanism is permeability this product is not advisable. Moreover, it was demonstrated that the chloride diffusion coefficient (in saturated condition) is reduced by the hydrophobic agents, however, the magnitude of this reduction is minor (reduced by 11% and 17%, depending on the product).

Energy dissipation in depth-sensing indentation as a characteristic of the nanoscratch behavior of coatings

Wear behavior of coatings has usually been described in terms of mechanical properties such as hardness (H) and effective elastic modulus (E*). Alternatively, an energy approach appears as a promising analysis taking into account the influence of those properties. In a nanoindentation test, the dissipated energy depends not only on the hardness and elastic modulus, but also on the elastic recovery (W(e)). This work aims to establish a relation between plastic deformation energy (E(p)) during depth-sensing indentation method and the grooving resistance of coatings in nanoscratch tests. An energy dissipation coefficient (K(d)) was defined, calculated as the ratio of the plastic to the total deformation energy (E(p)/E(t)), which represents the energy dissipation of materials. Reactive depositions using titanium as the target and nitrogen and methane as reactive gases were obtained by triode magnetron sputtering, in order to assess wear and nanoindentation data. A topographical, chemical and microstructural characterization has been conducted using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), wave dispersion spectroscopy (WDS), scanning electron (SEM) and atomic force microscopy (AFM) techniques. Nanoscratch results showed that the groove depth was well correlated to the energy dissipation coefficient of the coatings. On the other hand, a reduction in the coefficient was found when the elastic recovery was increased. (C) 2009 Elsevier B.V. All rights reserved.

An In-Depth Study of the Barkhausen Emission Signal Properties of the Plastically Deformed Fe-2%Si Alloy

This paper presents the results of the in-depth study of the Barkhausen effect signal properties for the plastically deformed Fe-2%Si samples. The investigated samples have been deformed by cold rolling up to plastic strain epsilon(p) = 8%. The first approach consisted of time-domain-resolved pulse and frequency analysis of the Barkhausen noise signals whereas the complementary study consisted of the time-resolved pulse count analysis as well as a total pulse count. The latter included determination of time distribution of pulses for different threshold voltage levels as well as the total pulse count as a function of both the amplitude and the duration time of the pulses. The obtained results suggest that the observed increase in the Barkhausen noise signal intensity as a function of deformation level is mainly due to the increase in the number of bigger pulses.

Penetration of hydrolysed soy protein-added brine and its effect on yield and pH of beef steaks from the biceps femoris muscle

This study was aimed to evaluate the penetration behaviour of different brines with tumbled beef steaks from the biceps femoris muscle, specifically their interactions with pH and effects on yield. Six muscles from different animals, divided into origin (OP) and insertion (IP) portions, were cut into 60 steaks of 2.5 cm thickness and tumbled for 30 or 60 min. The steaks were tumbled with two brines, with (WTB/HSP) or without (WTB) hydrolysed soy protein (HSP), and steaks that were not tumbled with brine or water were used as controls. Brine penetration was verified by measuring the amount of dye-containing brine (absorbance at 627 nm) recovered from homogenates of four thin (2 mm) slices from the surface of the beef steaks after tumbling. The WTB/HSP steaks exhibited greater (P < 0.05) brine penetration when tumbled for 60 min than for 30 min. The OP steaks showed greater yield and lower pH (P < 0.05) than IP steaks. HSP-added brine increased the water absorption and retention in the first slices of the steaks, and its efficiency was increased with a longer tumbling time. The portion of the biceps femoris muscle used influenced brine absorption and retention, impacting meat yield. (C) 2010 Elsevier Ltd. All rights reserved.