50 research outputs found

    DOMANDE E RISPOSTE SUL SISTEMA INTEGRATO DI VALUTAZIONE PREVENTIVA DELL'INQUINAMENTO ELETTROMAGNETICO AMBIENTALE A BASSISSIMA FREQUENZA PLEIA-CERT

    Get PDF
    L’ARPAT e l’IFAC-CNR collaborano ormai da oltre cinque anni allo sviluppo del Catasto degli Elettrodotti della Regione Toscana (CERT) e di un sistema integrato di applicazioni, denominato PLEIA (Power Line Electromagnetic Impact Assessment), per il suo utilizzo ai fini del calcolo del campo magnetico nello spazio circostante gli elettrodotti e, in particolare, della determinazione delle fasce di rispetto. Per rendere possibile a queste istituzioni un utilizzo corretto e consapevole degli strumenti realizzati e dei risultati da essi forniti, è stato indispensabile documentare innanzitutto i presupposti tecnici e metodologici che stanno alla base delle applicazioni sviluppate: a questo scopo, è venuto spontaneamente a crearsi un gruppo di lavoro informale tra esperti dell’ARPAT, dell’IFAC e della Regione Toscana. Il gruppo ha lavorato secondo un meccanismo virtuoso in cui, da un lato, si è cercato di formulare quesiti puntuali e ben definiti e, dall'altro, di rispondervi nel modo più chiaro ed esauriente possibile. Ne è scaturito un documento a domande e risposte che, opportunamente modificato, è riproposto in questa sede, perché mette in evidenza in modo semplice ma non banale alcuni rilevanti aspetti tecnici, e costituisce un buon documento introduttivo sulle potenzialità del sistema sviluppato. Le prime domande riguardano il sistema PLEIA-CERT in generale, mentre nella seconda parte si approfondiscono in particolare le modalità di calcolo delle fasce di rispetto che, anche alla luce di recenti sviluppi normativi, hanno assunto un ruolo di primaria importanza

    CCl 4 distribution derived from MIPAS ESA v7 data: intercomparisons, trend, and lifetime estimation

    Get PDF
    Abstract. Atmospheric emissions of carbon tetrachloride (CCl4) are regulated by the Montreal Protocol due to its role as a strong ozone-depleting substance. The molecule has been the subject of recent increased interest as a consequence of the so-called mystery of CCl4, the discrepancy between atmospheric observations and reported production and consumption. Surface measurements of CCl4 atmospheric concentrations have declined at a rate almost 3 times lower than its lifetime-limited rate, suggesting persistent atmospheric emissions despite the ban. In this paper, we study CCl4 vertical and zonal distributions in the upper troposphere and lower stratosphere (including the photolytic loss region, 70–20 hPa), its trend, and its stratospheric lifetime using measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), which operated onboard the ENVISAT satellite from 2002 to 2012. Specifically, we use the MIPAS data product generated with Version 7 of the Level 2 algorithm operated by the European Space Agency.The CCl4 zonal means show features typical of long-lived species of anthropogenic origin that are destroyed primarily in the stratosphere, with larger quantities in the troposphere and a monotonic decrease with increasing altitude in the stratosphere. MIPAS CCl4 measurements have been compared with independent measurements from other satellite and balloon-borne remote sounders, showing a good agreement between the different datasets.CCl4 trends are calculated as a function of both latitude and altitude. Negative trends of about −10 to −15 pptv decade−1 (−10 to −30 % decade−1) are found at all latitudes in the upper troposphere–lower stratosphere region, apart from a region in the southern midlatitudes between 50 and 10 hPa where the trend is positive with values around 5–10 pptv decade−1 (15–20 % decade−1). At the lowest altitudes sounded by MIPAS, we find trends consistent with those determined on the basis of long-term ground-based measurements (−10 to −13 pptv decade−1). For higher altitudes, the trend shows a pronounced asymmetry between the Northern and Southern hemispheres, and the magnitude of the decline rate increases with altitude. We use a simplified model assuming tracer–tracer linear correlations to determine CCl4 lifetime in the lower stratosphere. The calculation provides a global average lifetime of 47 (39–61) years, considering CFC-11 as the reference tracer. This value is consistent with the most recent literature result of 44 (36–58) years

    Antiangiogenic activity of semisynthetic biotechnological heparins: low-molecular-weight-sulfated Escherichia coli K5 polysaccharide derivatives as fibroblast growth factor antagonists.

    Get PDF
    OBJECTIVE: Low-molecular-weight heparin (LMWH) exerts antitumor activity in clinical trials. The K5 polysaccharide from Escherichia coli has the same structure as the heparin precursor. Chemical and enzymatic modifications of K5 polysaccharide lead to the production of biotechnological heparin-like compounds. We investigated the fibroblast growth factor-2 (FGF2) antagonist and antiangiogenic activity of a series of LMW N,O-sulfated K5 derivatives. METHODS AND RESULTS: Surface plasmon resonance analysis showed that LMW-K5 derivatives bind FGF2, thus inhibiting its interaction with heparin immobilized to a BIAcore sensor chip. Interaction of FGF2 with tyrosine-kinase receptors (FGFRs), heparan sulfate proteoglycans (HSPGs), and alpha(v)beta3 integrin is required for biological response in endothelial cells. Similar to LMWH, LMW-K5 derivatives abrogate the formation of HSPG/FGF2/FGFR ternary complexes by preventing FGF2-mediated attachment of FGFR1-overexpressing cells to HSPG-bearing cells and inhibit FGF2-mediated endothelial cell proliferation. However, LMW-K5 derivatives, but not LMWH, also inhibit FGF2/alpha(v)beta3 integrin interaction and consequent FGF2-mediated endothelial cell sprouting in vitro and angiogenesis in vivo in the chick embryo chorioallantoic membrane. CONCLUSIONS: LMW N,O-sulfated K5 derivatives affect both HSPG/FGF2/FGFR and FGF2/alpha(v)beta3 interactions and are endowed with FGF2 antagonist and antiangiogenic activity. These compounds may provide the basis for the design of novel LMW heparin-like angiostatic compounds

    1:2 Inclusion complex progesterone/HPBCD studied by Raman and NMR spectroscopy

    No full text
    Complexes between Progesterone (P) and β-cyclodextrin (BCD) to obtain water soluble formulations are widely known; since hydroxypropyl β-cyclodextrin (HPBCD) displays higher water solubility (48% p/v), we started experiments to achieve a better solubilization of the hormone, to obtain up to 50 mg/ml progesterone concentration in physiological solution, to formulate a suitable dosage form for progesterone therapy. We developed a production process in which the residual BCD (commercial HPBCD contains up to 0.8 % of unreacted material) is preliminarly separated by the formation of a poorly soluble complex. The stoichiometry and stability constant of the desired soluble complex were calculated by phase/solubility study. DSC and X-Ray analysis confirmed the absence of crystalline P in the final freeze-dried powder. The structural evaluation by spectroscopic analysis (Raman, FTIR and NMR) confirms the presence of an inclusion complex with a stoichiometry guest/host 1:2. The Raman spectrum of P shows tree sharp signals at 1616, 1664 and 1669 cm-1 due to the two carbonyls in position 3 and 20 of the steroid structure. HPBCD alone does not show signals in the considered area. P/HPBCD complex show a broad main signal at 1657 cm-1with a minor signal at 1691 cm-1 This change in the spectrum indicates the inclusion of the progesterone involving both rings A and D of the steroid structure. This idea was also confirmed by FT-IR spectroscopy (right). NMR experiment shows shifts of signals attributed to P protons 4, 18,19 and 21 indicating again a involvement of rings A and D in the inclusion complex (left)

    ATR/Raman and fractal characterization of HPBCD/progesterone complex solid particles

    No full text
    PURPOSE: Characterization of hydroxypropyl-beta-cyclodextrin/progesterone (HPBCD/P) complex solid particles obtained from an aqueous solution, by three different technological processes, with the aim of preparing ready-to-dissolve powders for injectable as well as solid oral formulations in progestinic therapy. METHODS: HPBCD/P complex in the 2:1 molar ratio was prepared in aqueous solution and obtained as dry solid particles by freeze-drying, by spray-drying and by fluid-bed evaporation of the solvent. The particles were characterized by mu-FT-IR, mu-Raman and X-ray spectroscopy, by thermal analysis (differential scanning calorimetry-DSC and thermogravimetry-TGA), by Karl Fischer (KF) titration, by image and fractal analysis and by BET specific surface area analysis. The structure of the complex was also defined by comparison of FT-IR and Raman spectra of progesterone with those of pregnenolone and testosterone, structurally related. Dissolution tests were also performed. RESULTS: Powders of the complex obtained by the three different methods are different in size and shape. Particles obtained by freeze-drying are flat and angular, irregularly shaped without any relation to known geometrical solid figures. Particles obtained by spray-drying are spherically shaped and display a very small size (5-10 microm), with evident deformations and depression of the external surface, due to the rapid evaporation of the solvent. Particles obtained by fluid bed technique have intermediate sizes, display a tri-dimensional structure and irregular surface, with small and rounded protuberances. Fractal dimension of the particle contour was found close to one unit for the microspheres obtained by spray-drying. FT-IR and Raman spectra confirm the occurrence of the complexation by the shift of representative bands of the two carbonyl groups in positions 3 and 20 of the complexed progesterone. X-ray diffractograms indicate the amorphous nature of all the types of particles, also suggested by the absence of any melting peak of the drug in DSC thermograms. The samples contain different amounts of humidity: particles obtained by fluid-bed method demonstrated non-porous in BET analysis. Dissolution of different types of particles is complete after 3 min and only negligible differences could be appreciated among the three powders. CONCLUSIONS: - mu-FT-IR, mu-Raman and X-ray spectroscopy, and the dissolution test did not reveal defined differences among the three different types of particles, confirming occurrence of the complex in the solid state. The spherical shape, the very small size and the low value of the contour fractal dimension allows better technological performance of the particles obtained by spray-drying: this drying process appears the most promising one to prepare dry particles of the HPBCD/P complex, in view of its formulation in the fast preparation of extemporaneous injectable solutions and solid oral formulations intended for sublingual delivery

    New injectable formulation containing water soluble Progesterone-Hydroxypropyl-beta-cyclodextrin complex

    No full text
    Progesterone (P) is a natural hormone used as a drug to control reproductive function and for postmenopausal therapy. Oral and vaginal routes display low bioavailability and, in addition, oral route has a limited usefulness, because of P short half-life and extensive degradation after absorption. Therefore the injection route should be the preferred choice, since the oily solution and the aqueous suspension allow only intramuscolar administration. This encourages the research of new injectable pharmaceutical form with increase of the patient compliance. Water-soluble P formulations represent a suitable solution, because they could be administered also by subcutaneous route, therefore allowing auto medication and less pain during the treatment is expected. Pitha et al. described the use of Cyclodextrins to increase the water solubility of Progesterone (P), through the formation of an inclusion complex to obtain a water soluble formulation (1). Also other authors, using different physico-chemical methods (2, 3, 4), reported experimental evidences of the inclusion complex formation between P and b-cyclodextrin and derivatives. Among the cyclodextrins tested hydroxypropyl-b-cyclodextrin (HPBCD) is a suitable choice for formulations containing therapeutic concentration of P. The therapeutic dosage of P by injection varies from 5 to 200 mg. as a function of the specific pathology (5). HPBCD, displaying high water solubility (48% p/v), allows solubilisation of large quantity of P. Considering the formation of a 1:2 complex, it is possible to obtain solutions up to 50 mg/ml P, which is a considerable dosage in the progesterone therapy. In the development of P/HPBCD complex we observed the formation of a light precipitate under stability ICH conditions. Choi et al (4) and also by Pitha et al (1) noticed the precipitate formation, but its chemical structure was not elucidated. This work describes a method to obtain a P/HPBCD without insoluble particles, the physico-chemical characterization of the precipitate and of the purified inclusion complex

    Screening of Spotlight CSK images for large area monitoring and detection of infrastructures

    No full text
    This paper presents an automatic pre-screening algorithm of SAR images of huge size (more than 20;000x20;000 pixels), which is capable to identifying extended infrastructures in an effective and computationally efficient way. The algorithm is tested on true one-look Cosmo-SkyMed SAR image data for target detection purposes on an airport scenario. Both visual and objective results are presented to show the potentials of the proposed method
    corecore