190 research outputs found
Artificial neural networks for 3D cell shape recognition from confocal images
We present a dual-stage neural network architecture for analyzing fine shape
details from microscopy recordings in 3D. The system, tested on red blood
cells, uses training data from both healthy donors and patients with a
congenital blood disease. Characteristic shape features are revealed from the
spherical harmonics spectrum of each cell and are automatically processed to
create a reproducible and unbiased shape recognition and classification for
diagnostic and theragnostic use.Comment: 17 pages, 8 figure
Plasma Citrulline : a New Marker of Gut Epithelium Alteration in Obese Patients?
Objectives: In the last decade gut microbial diversity was associated with the pathogenesis of obesity
in humans. Plasma citrulline was a simple and accurate biomarker for the severity of intestinal
failure and was associated with short bowel syndrome and alteration of gut permeability, being
developed as an alternative to D-xylose tolerance test for the diagnosis of an abnormal small
intestinal absorption of nutrients. This study was performed to ascertain whether obesity might
be associated with dysregulation of epithelial gut function. Methods: Fifteen obese individuals (5
M/10 F; BMI 37.4 \ub1 6.1 Kg/m2; 42 \ub1 6 yrs) and 15 healthy gender- and age-matched controls (6
M/9 F BMI: 22.7 \ub1 2.1 Kg/m2; 39 \ub1 7 yrs) underwent D-xylose load (25 g) and plasma citrulline,
plasma insulin, glucose and lipid profile testing. Results: Plasma citrulline was significantly lower
in the obese group (p = 0.045) with respect to controls, whilst total cholesterol, LDL and tryglicerides
concentration, insulin level and HOMA-IR were significantly higher in obese patients. In contrast,
after D-xylose load no difference in serum xylose was found between the two groups (p = ns).
Conclusions: Obese patients show a decreased citrulline concentration with respect to lean subjects.
Since citrulline is a known marker of intestinal health, alterations in the gut epithelium are likely
to be associated with the obesity syndrome. We propose to measure citrulline level in obese patients
on a routine basis
An indoor air quality study at the Ambrosiana Art Gallery (Milan)
Indoor air quality in historical buildings and museums is receiving increasing concern nowadays among the scientific community. Many sources of pollutants, both gases and particles, are responsible for the accelerated decay of the works of art. Knowing the levels of indoor pollutants is of critical importance to apply conservation and preservation strategies of cultural heritage [1, 2].
Air quality at the Ambrosiana Art Gallery in Milan has been monitored (in the two periods October-November 2017 and March 2018) inside the room where the preparatory cardboard of the School of Athens (1509-1511), one of most important masterpieces by Raffaello Sanzio, is stored. The cardboard is currently undergoing restoration and will be exposed in a new showcase that will be realized according to the specific environmental and microclimatic conditions of the room. The objective of this study was to monitor the concentration and chemical composition of the aerosol particulate matter (PM) up to the nano fraction, which represents the most dangerous fraction for the works of art surfaces. The monitoring campaigns have been carried out in parallel in the Raffaello room (at present not accessible to visitors) and in a nearby room open to visitors. The set of instuments employed included: a TSP sampler (total suspended particles) (Tecora, Pollution Check, Bravo M2); a DustMonit (Contec) analyzer that measures the concentration of dust up to PM1 and provides 13 granulometric classes (up to 300 nm); a NanoScan Nanoparticle sizer 3910 (TSI) instrument that measures particles concentration up to 10 nm; two instruments for the determination of black carbon (BC) in continuous and in particular a SILIIS instrument (Sphere-Integrated Laser Induced Incandescence Spectroscopy) and a micro aethalometer (AE51 Magee Scientific).
Quartz fiber filters have been employed to collect TSP samples to be submitted to chemical analysis. The filters have been fully chemically characterized: main ionic constituents and the carbonaceous fraction (i.e organic carbon, OC and elemental carbon, EC) have been analyzed by IC (ion chromatography) and TOT (thermal optical transmittance) respectively. A particles morphological characterization has been carried out on PM collected on polycarbonate filters by means of SEM-EDX (scanning electron microscopy coupled with energy dispersive X-ray spectroscopy).
Outdoor PM concentrations, obtained for the two seasons (autumn 2017 and spring 2018) from ARPA monitoring stations placed in the city center, have been correlated with indoor data
Performance evaluation of a commercial protective coating through field-exposure tests on three stone substrates
In the last decades, there have been several studies on Cultural Heritage regarding the performance of protective and consolidating coatings for the prevention of decay. A coating must have several characteristics such as efficiency, breathability, and must be durable and reversible. In this research work, the performance of a commercial protective product (Fosbuild FBLE 200) was evaluated. This coating is composed of a TiO2 nanopowder dispersed in an aqueous solution of an acrylic polymer. The product, which exhibits depolluting, antimicrobial, water-repellent and self-cleaning properties, has been applied on three different lithotypes: Carrara marble, Noto stone, and Comiso stone. Field-exposure tests were carried out in two different outdoor environments (Catania and Palermo) in order to assess its suitability. Promising results were obtained for the Carrara marble after one year of exposure; however, a decrease in effectiveness was observed at the end of the second year
The assessment of the carbonaceous component in black crusts damaging the stone surfaces of historical monuments.
The issue of conservation of the monumental heritage is mainly related to atmospheric pollution that causes the degradation of stone surfaces. Black crusts can be formed as a result of different chemical and physical reactions between the stone surface and environmental factors (such as gaseous pollutants and aerosol particulate matter, PM). These black layers present on the stone monuments reflect the composition of the aerosol particulate matter to which the surfaces are exposed. In particular elemental carbon (EC, also known as black carbon, typically emitted by combustion processes) is the PM component responsible for the characteristic black color of the crusts where it is embedded together with calcium sulphate due to the conversion of calcium carbonate, the main constituent of the stone. Organic carbon (OC) represents the other carbonaceous component of PM and it is present in the black crusts, too. It is of both primary or secondary origin and is linked to numerous sources (traffic, heating plants, biomass burning, etc.).
A deep knowledge of the crust composition in terms of OC and EC optical properties is mandatory in order to get information on the sources responsible for the surface darkening.
OC/EC in PM samples are generally quantified by a reference method (TOT, Thermal Optical Transmittance) not suitable for the analysis of these components in the crusts.
A new approach for OC/EC quantification based on a thermal protocol and including CHN and TGA analyses, has been here proposed. The method validation has been performed analyzing suitable reference standard samples prepared by mixing different chemical species in order to simulate the composition of the black crusts present on the monument surfaces.
In addition the characterization of OC optical properties with UV-visible spectrometry has been performed, to understand the role of light absorbing carbon (i.e. brown carbon) on surface stone darkening. The chemical composition of OC was further investigated with Fourier Transform infrared spectrometry (FT-IR) to identify the contribution of the different organic functional groups to the ageing/browning of stone surfaces.
This research aims to get a new simple method for the evaluation of the carbonaceous component of the black crusts which are formed on carbonate stone surfaces. The protocol has been applied to some real samples of black crusts of different provenance
Effetti tossicologici del particolato ultrafine emesso da impianti residenziali a biomassa: note sul progetto TOBICUP
Effetti tossicologici del particolato ultrafine emesso da impianti residenziali a biomassa : note sul progetto TOBICUP
This work summarises the main findings of the TOBICUP (Toxicity of BIomass Combustion generated Ultrafine Particles) project. The project has investigated the physio-chemical features and toxicological response of ultrafine particles (UFPs) from biomass-fuelled domestic stoves. Experimental determinations consider both UFP samples collected at the stack of wood log and pellet stoves and environmental
samples collected at a site where biomass burning for domestic heating is the main source of airborne UFPs. Results for the stack samples show that combustion in
pellet stoves is more complete, producing UFPs that determine toxicological responses per unit input energy less relevant compared with wood log stoves. Results for the environmental samples show a larger contribution from domestic heating to airborne UFPs in wintertime, traced by the higher content of levoglucosan and potassium than in summertime. However,toxicological response are influenced by the different reactivity of the atmosphere at seasonal level: in wintertime, genotoxic effects prevail due to the larger concentration of PAH and levoglucosan; in summertime, pro-inflammatory effects are more relevant due to the higher degree of oxidation of UFPs, favoured by the
stronger photochemical processes occurring in the warm season
Optical properties of aerosol particles over the Amazon rain forest: From background to biomass burning conditions
Atmospheric aerosols over the Amazon rainforest are strongly influenced by biomass burning activities in the southern regions of the Amazon Basin between July and October. This implies a complete change of the physical and chemical aerosol properties from the wet season, which is dominated by Primary Biological Aerosol Particles (PBAP) and biogenic secondary organic aerosols. Biomass burning emissions are highly loaded with light-absorbing aerosols, like black and brown carbon (BC and BrC, respectively). The latter one consists of a fraction of organic carbon that is able to absorb visible radiation (Andreae and Gelencs\ue9r, 2006). BrC is a strong absorber at near-UV to UV wavelengths. Therefore, light absorption by this component is wavelength dependent. This wavelength dependency, expressed as the absorption \uc5ngstr\uf6m exponent (AAE), has been used as a parameter to estimate the influence of biomass burning aerosols to total aerosol light absorption. However, the biogenic BrC contribution remains to be studied and could be significant under pristine conditions. The measurements presented here were carried out at the Amazon Tall Tower Observatory (ATTO), located 150 km NE of the city of Manaus, in the Uatum\ue3 Sustainable Development Reserve in Amazonas State, Brazil. The aerosol inlet (60 m high, 2.5 cm diameter) is installed on an 81-m triangular mast. The measurement period, from June to September 2014, includes the wetto- dry transition season (June-July) and part of the dry season (August and beginning of September). The optical properties were measured online by different instruments: 3-wavelengths nephelometer, Multi-Angle Absorption Photometer (MAAP), Single Particle Soot Photometer (SP2) and a 7-wavelength Aethalometer. Additionally, MAAP filter samples were analyzed by the Multi-Wavelength Absorbance Analyzer (MWAA) (Massab\uf2 et al, 2013), as well as levoglucosan analysis was carried out for filters collected between 18-22 August 2014. The average light absorption coefficient at 637 nm was 1.0 \ub1 0.6 Mm-1 and 5.5 \ub1 3.9 Mm-1, during the wet-to-dry transition and the dry season, respectively. Here we concentrate on measurements during 18-22 August 2014 (Figure 1) when a high absorption coefficient was measured at 637 nm, averaging 10 \ub1 3 Mm-1. The AAE calculated from MWAA measurements increased from less than 1.0 to values higher than 1.4, indicating the presence of BrC aerosol particles. This period is characterized by a long-range transport of biomass burning aerosol (confirmed by backward trajectory analysis). Levoglucosan analysis reveals significantly increased concentration but is still relatively low compared to measurements close to the source (Graham et al, 2002). Nevertheless, AAE and levoglucosan concentration show a significant correlation (r\ub2 > 0.9)
Particelle ultrafini emesse dalla combustione di biomassa: risultati di uno studio su composizione e tossicologia
- …