Search results for "GC"

Perturbation vectors to evaluate air quality using lichens and bromeliads: a Brazilian case study.

2017

10 pages; International audience; Samples of one lichen species, Parmotrema crinitum, and one bromeliad species, Tillandsia usneoides, were collected in the state of Rio de Janeiro, Brazil, at four sites differently affected by anthropogenic pollution. The concentrations of aluminum, cadmium, copper, iron, lanthanum, lead, sulfur, titanium, zinc, and zirconium were determined by inductively coupled plasma-atomic emission spectroscopy. The environmental diagnosis was established by examining compositional changes via perturbation vectors, an underused family of methods designed to circumvent the problem of closure in any compositional dataset. The perturbation vectors between the reference s…

Absorption of polycyclic aromatic hydrocarbons by pinus bark: analytical method and use for environmental pollution monitoring in the Palermo area (S…

2007

Abstract In the light of using biomaterial as pollutants sorbents for the environmental biomonitoring, we report here the results of the absorption of polycyclic aromatic hydrocarbons (PAHs) by pine bark. Quantitative analysis of 19 different polycyclic aromatic compounds was performed, after Soxhlet extraction in dichloromethane, by means GC–MS technique. Pinus was chosen due to its wide distribution in the Mediterranean area. The passive absorption of PAH by pine bark in the metropolitan areas allowed us to evaluate the air quality of Palermo. The obtained results showed a very high range of PAHs concentrations, from 33 μg/kg (bark dry weight), as ΣPAHs, at the control site to 1015 μg/kg …

Gas chromatography-mass spectrometry study of polycyclic aromatic hydrocarbons in grass and milk from urban and rural farms

2000

Polycyclic aromatic hydrocarbon (PAH) levels were studied in grass and milk sampled at two farms, one located in a non-contaminated, rural area, and another located in a urban area close to PAH sources such as highways, busy roads, fuel-powered trains and a steel plant. PAH concentration were measured by gas chromatography coupled to mass spectrometry (GC-MS) using internal deuterated standards. In grasses, unexpectedly, although the sum of PAH concentrations was only slightly higher at the urban farm (83.1 ± 16.1 ng g−1) than the rural farm (51.8 ± 10.6 ng g−1), this difference was not observed for all PAH members. This absence of a striking difference of PAH levels between urban and rura…

SCHEDE DEI PROVVEDIMENTI SANZIONATORI DI PRATICHE COMMERCIALI SCORRETTE, PUBBLICITÀ INGANNEVOLE E COMPARATIVA ILLECITA EMESSI DALL’AGCM.

2013

SCHEDE DEI PROVVEDIMENTI SANZIONATORI DI PRATICHE COMMERCIALI SCORRETTE, PUBBLICITÀ INGANNEVOLE E COMPARATIVA ILLECITA EMESSI DALL’AGCM. CONCORRENZA…

2012

Modulation of Nrf2/ARE pathway by food polyphenols: a nutritional neuroprotective strategy for cognitive and neurodegenerative disorders

2011

In recent years, there has been a growing interest, supported by a large number of experimental and epidemi-ological studies, for the beneficial effects of some phenolic substances, contained in commonly used spices and herbs, in preventing various age-related pathologic conditions, ranging from cancer to neurodegenerative diseases. Although the exact mechanisms by which polyphenols promote these effects remain to be elucidated, several reports have shown their ability to stimulate a general xenobiotic response in the target cells, activating multiple defense genes. Data from our and other laboratories have previously demonstrated that curcumin, the yellow pigment of curry, strongly induces…

Topical issue on Ecological Complex Systems

2008

Oxidation effects in antiaggregogenic properties of Epigallocatechingallate

2021

Epigallocatechin-gallate (EGCG), the most abundant flavonoid in green tea, has been extensively studied for its potential in the treatment of amyloid related disorders. This molecule was found to modulate abnormal protein self-assembly, reducing resulting cellular toxicity. EGCG is known to suppress or to slow down the aggregation processes of several proteins, thus supporting the idea that general mechanisms regulate its anti-aggregogenic effects and, interestingly, in the oxidised form it demonstrated an higher efficiency in reducing protein aggregation with respect to intact molecule. We here investigate the effects of intact and oxidized EGCG the thermal aggregation pathway of Bovine Se…

Zvaigžņotā Debess: 2011/12, Ziema (214)

2011

Saturs: Gamma staru astronomijas problēmas ; Apollo-14 Mēness ekspedīcija ; A.Laure. Protoplanetāro miglāju stadija zvaigžņu evolūcijā ; A.A. Jaunumi īsumā: Oglekļa zvaigzne un rentgenstaru avots ; A.Alksnis. Heršels ielūkojas Miras galvā ; D.Docenko. Jauns dziļš debess apskats WiggleZ ir pabeigts: gaidām rezultātus ; A.A. Jaunumi īsumā: Pundurplanēta Erīda ir precīzi izmērīta. Atvērto durvju dienā Garhingā... ; M.Gertāns. Iepazīstot Kenedija kosmosa centru un atvadoties no Space Shuttle ; J.Dambītis. Ievērojams Latvijas matemātiķis – docents Nikolajs Brāzma (1913-1966) ; J.Jansons. Fiziķu centieni 1950.-1960. gados atgriezt fundamentālo zinātni Universitātē ; V.Fļorovs, A.Cēbers, D.Bočarov…

Erle-copter Simulation using ROS and Gazebo

2020

The recent decrease in the price as well as size of semi-conductor logic and due to significant advancements in technologies such as microcontrollers, motors and sensors, the application of quadcopters in several fields has been achieved. However, testing of quadcopter prototypes still has a risk of damage due to faults and unexpected behavior. Hence, a method of testing of quadcopters in simulation mimicking the actual conditions of the real environment in an actual hardware test has been proposed. For this purpose, Gazebo simulator integrated with ROS has been chosen for the simulation of the path of the quadcopter. Moreover, the software Matlab/Simulink has been interfaced with Gazebo in…