63 research outputs found

    Effects of sources and meteorology on particulate matter in the Western Mediterranean Basin: an overview of the DAURE campaign

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    DAURE (Determination of the Sources of Atmospheric Aerosols in Urban and Rural Environments in the Western Mediterranean) was a multidisciplinary international field campaign aimed at investigating the sources and meteorological controls of particulate matter in the Western Mediterranean Basin (WMB). Measurements were simultaneously performed at an urban-coastal (Barcelona, BCN) and a rural-elevated (Montseny, MSY) site pair in NE Spain during winter and summer. State-of-the-art methods such as 14C analysis, proton-transfer reaction mass spectrometry, and high-resolution aerosol mass spectrometry were applied for the first time in the WMB as part of DAURE. WMB regional pollution episodes were associated with high concentrations of inorganic and organic species formed during the transport to inland areas and built up at regional scales. Winter pollutants accumulation depended on the degree of regional stagnation of an air mass under anticyclonic conditions and the planetary boundary layer height. In summer, regional recirculation and biogenic secondary organic aerosols (SOA) formation mainly determined the regional pollutant concentrations. The contribution from fossil sources to organic carbon (OC) and elemental carbon (EC) and hydrocarbon-like organic aerosol concentrations were higher at BCN compared with MSY due to traffic emissions. The relative contribution of nonfossil OC was higher at MSY especially in summer due to biogenic emissions. The fossil OC/EC ratio at MSY was twice the corresponding ratio at BCN indicating that a substantial fraction of fossil OC was due to fossil SOA. In winter, BCN cooking emissions were identified as an important source of modern carbon in primary organic aerosol

    An Overview of Three Promising Mechanical, Optical, and Biochemical Engineering Approaches to Improve Selective Photothermolysis of Refractory Port Wine Stains

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    During the last three decades, several laser systems, ancillary technologies, and treatment modalities have been developed for the treatment of port wine stains (PWSs). However, approximately half of the PWS patient population responds suboptimally to laser treatment. Consequently, novel treatment modalities and therapeutic techniques/strategies are required to improve PWS treatment efficacy. This overview therefore focuses on three distinct experimental approaches for the optimization of PWS laser treatment. The approaches are addressed from the perspective of mechanical engineering (the use of local hypobaric pressure to induce vasodilation in the laser-irradiated dermal microcirculation), optical engineering (laser-speckle imaging of post-treatment flow in laser-treated PWS skin), and biochemical engineering (light- and heat-activatable liposomal drug delivery systems to enhance the extent of post-irradiation vascular occlusion)

    Estimation of local and external contributions of biomass burning to PM2.5 in an industrial zone included in a large urban settlement

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    A total of 85 PM2.5 samples were collected at a site located in a large industrial zone (Porto Marghera, Venice, Italy) during a 1-year-long sampling campaign. Samples were analyzed to determine water-soluble inorganic ions, elemental and organic carbon, and levoglucosan, and results were processed to investigate the seasonal patterns, the relationship between the analyzed species, and the most probable sources by using a set of tools, including (i) conditional probability function (CPF), (ii) conditional bivariate probability function (CBPF), (iii) concentration weighted trajectory (CWT), and (iv) potential source contribution function (PSCF) analyses. Furthermore, the importance of biomass combustions to PM2.5 was also estimated. Average PM2.5 concentrations ranged between 54 and 16 μg m−3 in the cold and warm period, respectively. The mean value of total ions was 11 μg m−3 (range 1–46 μg m−3): The most abundant ion was nitrate with a share of 44 % followed by sulfate (29 %), ammonium (14 %), potassium (4 %), and chloride (4 %). Levoglucosan accounted for 1.2 % of the PM2.5 mass, and its concentration ranged from few ng m−3 in warm periods to 2.66 μg m−3 during winter. Average concentrations of levoglucosan during the cold period were higher than those found in other European urban sites. This result may indicate a great influence of biomass combustions on particulate matter pollution. Elemental and organic carbon (EC, OC) showed similar behavior, with the highest contributions during cold periods and lower during summer. The ratios between biomass burning indicators (K+, Cl−, NO3−, SO42−, levoglucosan, EC, and OC) were used as proxy for the biomass burning estimation, and the contribution to the OC and PM2.5 was also calculated by using the levoglucosan (LG)/OC and LG/PM2.5 ratios and was estimated to be 29 and 18 %, respectively

    Long-pulsed 1064 nm Nd:YAG laser improves hypertrophic port-wine stains

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    Hypertrophic port-wine stains (PWS) usually respond poorly to pulsed dye laser treatment. The long-pulsed 1064 nm Nd:YAG laser can target deeper situated vessels and may therefore be more effective. To evaluate the efficacy and safety of the Nd:YAG laser for the treatment of hypertrophic PWS. In a retrospective cohort study, all hypertrophic PWS patients treated with the Nd:YAG laser between 2005 and 2011 were invited for follow-up. Clinical improvement was assessed using Physician Global Assessment (PhGA) and Patient Global Assessment (PGA). Assessment was obtained in 32 of 44 eligible patients (mean age 51.4 years), after a mean of 2.8 (SD ± 2.1) Nd:YAG laser treatments. Good or excellent improvement of hypertrophy was found in a majority of patients, both by PhGA (91%) and PGA (93%). Good or excellent improvement of colour was found in 63% of patients by PhGA, and in 87% by PGA. Recurrence of hypertrophy was seen in three patients. All but two patients would recommend Nd:YAG treatment to other patients. Mild to moderate scars were seen in seven patients, hypopigmentation in 14 patients. The 1064 nm Nd:YAG laser is highly effective in the treatment of hypertrophic PWS with only a few treatments needed. Mostly mild side effects were seen in half of all patients. Hypertrophy seems to respond better than colour. To further improve colour, a combination with pulsed dye laser treatment is advisory. Observation of immediate clinical endpoints is important when using the Nd:YAG laser, to optimize outcomes and reduce side effect

    Speciation of organic aerosols in the Saharan Air Layer and in the free troposphere westerlies [Discussion paper]

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    We focused this research on the composition of the organic aerosols transported in the two main airflows of the subtropical North Atlantic free troposphere: (i) the Saharan Air Layer – the warm, dry and dusty airstream that expands from North Africa to the Americas at subtropical and tropical latitudes – and (ii) the westerlies – which flows from North America through the North Atlantic at mid and subtropical latitudes. We determined the inorganic compounds (secondary inorganic species and elemental composition), elemental carbon and the organic fraction (bulk organic carbon and organic speciation) present in the aerosol collected at Izaña Observatory, ~ 2400 m a.s.l. in Tenerife Island.This study was performed within the context of the projects AEROATLAN (CGL2015-66299-P; 15 MINECO/FEDER) and TEAPARTICLE (CGL2011-29621), supported by the Ministry of Economy and Competitiveness of Spain and the European Regional Development Fund (ERDF)

    Double Pass 595?nm pulsed dye laser at a 6 minute interval for the treatment of port-wine stains is not more effective than single pass

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    Background Pulsed dye laser (PDL) is the first choice for treatment of port wine stains (PWS). However, outcome is highly variable and only a few patients achieve complete clearance. The objective of the study was to compare efficacy and safety of single pass PDL with double pass PDL at a 6 minute interval. Methods: We conducted a randomized within- patient controlled study on PWS resistant to multiple single pass PDL treatments. In each patient two similar PWS areas were randomly allocated to PDL treatment (595 nm, 7 mm spot size, 1.5 mseconds pulse duration) using, as a control treatment, a single pass (12 J/cm(2)) or, as a new treatment, a double pass PDL (11 J/cm(2), second pass 6 minutes after the first pass). Both test areas were treated two times, 8 weeks apart. PWS clearance was assessed by two blinded dermatologists, and by color measurement (L*a*b) using reflectance spectroscopy, at 3 months follow- up. Results: Sixteen out of 17 included patients completed follow- up. The mean number of treatments before inclusion was 15. Overall color assessed by spectrophotometer showed no improvement for either single or double pass PDL. Blinded Physician Global Assessment and Patient Global Assessment showed a high variability in outcome, with mostly only moderate improvement of the PWS for either single pass or double pass PDL. Furthermore, there was no significant difference in any of the outcomes between single pass and double pass PDL. Conclusion: At the chosen settings and after two treatment sessions, double pass PDL at a 6 minute interval does not result in improved clearance of PWS as compared to single pass treatment. Lasers Surg. Med. 44: 199- 204, 2012. (C) 2012 Wiley Periodicals, In

    Hypertrophy in port-wine stains: Prevalence and patient characteristics in a large patient cohort

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    Background: Port-wine stains (PWS) may thicken and darken with age. Little is known about the pathogenesis and epidemiology of PWS hypertrophy because of the lack of large studies. Objective: We sought to assess the prevalence and characteristics of patients with hypertrophic PWS. Methods: Medical records and clinical photographs of all patients with PWS visiting our clinic between 2005 and 2009 were examined to identify hypertrophy. Patients were sent questionnaires regarding their hypertrophic PWS. Results: In all, 335 patients (age 0-81 years; 69% female) with PWS were included. Hypertrophy was found in 68 patients (20%; 32 male, 36 female) and classified as thickened (5%), nodular (8%), or both (7%). Color of hypertrophic PWS was mainly red (50%) or purple (44%). Patients with hypertrophy in their PWS were mostly (68%) older than 40 years, and rarely (7%) younger than 20 years. When older than 50 years, 71% of all patients had hypertrophy in their PWS. Median age of onset of PWS hypertrophy was 31 years (12 years for thickened, 39 years for nodular). Limitations: This was a retrospective study in a selected population. Conclusion: Hypertrophy is an important feature in the development of PWS and affects a majority of patients older than 50 years. Depth of color of the PWS is associated with hypertrophy, whereas location and size appear not to be related. More attention should be drawn to therapy and prevention of hypertrophic PWS. Diffuse thickening and nodules should be distinguished, as a different age of onset may indicate different pathomechanisms. (J Am Acad Dermatol 2012; 67:1214-9.
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