79,626 research outputs found
Geologia e geomorfologia
No full textinquadramento geologico e geomorfologico della provincia di Padova, con riferimento alle problematiche di cartografia dei suoli
An LC-MS Assay with Isocratic Separation and On-Line Solid Phase Extraction to Improve the Routine Therapeutic Drug Monitoring of Busulfan in Plasma
No full textBackground: Busulfan (Bu) requires therapeutic drug monitoring (TDM) in subjects undergoing a conditioning regimen for hematopoietic stem cell transplantation (HSCT). To speed up the procedure and increase reproducibility, we improved our routine LC-MS/MS assay using the on-line solid-phase extraction (SPE) of samples. Methods: A protein precipitation (PP) step was performed before the on-line SPE of Bu from 200 μL of plasma spiked with octa-deuterated Bu (D8-Bu) as the internal standard. Bias was assessed with respect to our routine LC-MS/MS Bu assay with off-line extraction using the Passing-Bablok robust regression. Root cause of bias for individual samples was assessed by analyzing the regression residuals. Results: The method was linear in the range 37.75-2,416 ng/mL (r2>0.999), with 19.74 ng/mL LLOQ and 10.5% CV at 20 ng/mL. Precision and accuracy were both within ±5%, and neither appreciable matrix nor carryover effects were observed. The Passing-Bablok regression analysis returned a 0.99 slope (95% Cl: 0.97 to 1.01) and -6.82 intercept (95% Cl: -15.23 to 3.53). Residuals analysis against the 2.5th-97.5th percentiles range showed four samples with significant bias individually. Conclusions: The method presented can be successfully employed for the routine analysis of Bu in plasmatic samples, and can replace the LC-MS/MS method with off-line extraction without any statistically significant overall bias. In this regard, samples with individual significant bias were reasonably produced by preanalytical issues which had no relation with the conversion to the on-line SPE extraction
Padova città tre volte murata
No full textLa pianura alluvionale su cui sorge Padova è costituita da diverse unità geomorfologiche di età comprese tra l'ultimo massimo glaciale (29 - 17,5 ka) e l'attuale, relative ai fiumi Brenta e Bacchiglione. Il centro storico della città corrisponde ad un ampio mound archeologico che si è andato formando a partire dall'età del Ferro, in un'area perifluviale già insediata nella tarda età del Bronzo. Lo sviluppo della città antica è avvenuto sulle sponde del F. Bacchiglione, che attraversa Padova dall'inizio del I millennio. La presenza di paleoalvei del Brenta ha condizionato la struttura urbana in età veneto antica, romana e medievale. Alcuni tratti delle mura trecentesche seguono dei paleoalvei
Biological variation of neuroendocrine tumor markers chromogranin A and neuron-specific enolase
No full textObjectives: Chromogranin A (CgA) and neuron-specific enolase (NSE) are biomarkers for neuroendocrine tumors. Although the knowledge of their biological variation (BV) is critical, only one study for CgA and no data for NSE are available. We report a definitive assessment of BV components of these biomarkers in the same cohort of subjects by an accurately experimental protocol. Design and methods: We collected five blood specimens from each of 22 healthy volunteers (10 men and 12 women, 23–54 years) on the same day every two weeks for two months. Serum specimens were stored at −80 °C until analysis and analyzed in a single run in duplicate. Data were analyzed by ANOVA. Results: Serum CgA concentrations were significantly higher for women than for men (P=0.01), whereas no difference was found for NSE. Intra-individual variance was not different between genders for both biomarkers. Within- and between-subject CVs were 16.3% and 33.5% for CgA and 13.6% and 11.5% for NSE, respectively. CgA showed marked individuality, suggesting that the use of population-based reference limits is inadequate for its interpretation. Conversely, the low individuality of NSE allows the use of a single reference interval. Reference change values were 46% for CgA and 39% for NSE. Desirable analytical goals for imprecision, bias, and total error were b8.2%, ±9.3%, and ±22.8% for CgA, and b6.8%, ±4.5%, and ±15.7% for NSE, respectively. Conclusion: In this study, we defined BV components of serum CgA and NSE and derived indices that may improve the clinical use of these biomarkers
Effects of buflomedil in a group of patients with chronic peripheral arterial diseases. Clinical and hemorheological evaluation
No full textFifty-three patients suffering from chronic arterial diseases of the lower limbs were treated with buflomedil, a vasoactive drug with vasodilating and hemorheological action on the microcirculation. The patients suffered from pain on walking or pain at rest; they were given 300 mg buflomedil orally twice a day for a period of about 2 months. The walking distance before pain onset was checked in all patients before and after the trial. Blood and plasma viscosity, haematocrit and fibrinogen and a Doppler velocimetry were also recorded. A significant improvement of the walking distance before pain onset was observed in nearly all patients, and in most patients the morphology of the velocity waves improved, too. No clear correlation between the positive clinical results and the hemorheological parameters studied could be observed
Alluvial megafans in the foreland of Southern Alps
No full text1. Introduction
Along the Southern Alps several large cone-shaped landforms are present. These relate to the alluvial systems fed by the main valleys and presently display an extent of 300-3000 km2, with a length of 30-70 km. We reviewed the available information related to the geomorphological, stratigraphical and geochronological aspects of these alluvial systems with the aim to identify the global forcing factors and the local constraints which influenced their late Quaternary evolution.
The study area extends in the Alpine foreland for about 25,000 km2 and corresponds to the northern sector of the Po Plain from Ticino River to Garda Lake (i.e. the Lombard Plain: LP), the Venetian-Friulian Plain (VFP) and part of the Adriatic shelf. The related Alpine rivers drain a total mountain catchment of about 50,000 km2, with maximum elevations ranging between 2800-4810 m.
2. Results
The largest cone-shaped depositional systems of the VFP have been described as alluvial megafans for their evident longitudinal differentiation (Fontana, et al., 2008; 2010). This characteristic is displayed also by several systems of the LP, but these were before considered only in their gravelly sector (Guzzetti et al., 1997; Marchetti, 2001). The steep piedmont sector consists of amalgamated gravels, while the distal portion has a gradient <2‰ and is dominated by fine sediments.
In all the megafans the major depositional phase occurred between 26-19 ka cal BP, during the LGM marine lowstand, when the Alpine glaciers reached the plain and fed the related glaciofluvial systems. The easternmost megafans partly extended also on the Adriatic shelf whereas, West from Garda Lake, their downstream development was limited by the existence of the Po river plain. The thickness of LGM alluvial sedimentation ranges between 30-15 m and pinches out about 25 km from the present coast.
Soon after the ice decay, since 19-17 ka cal BP, the sedimentary delivery from Alpine catchments to the plain dramatically decreased and in the central Alps large intramontane lakes formed, trapping the bedload almost completely. Thus, an erosive phase affected the whole pede-Alpine sector, leading the rivers to entrench for tens of meters in their LGM megafans. The funneling effect created by the incisions allowed the gravels to arrive tens of kilometers downstream than in LGM. In the Venetian-Friulian megafans a single valley formed in the piedmont sector, while 2-5 fluvial incisions developed in the distal sector. But these incised landforms have been almost completely filled by a depositional lobe formed in the last 8 ka, partly triggered by the marine highstand.
The Alpine tributaries of Po haven’t yet been affected by sea-level influence and they still flow along a single incision from their megafan apex to the junction with Po.
3. Conclusions
Alluvial megafans along the Southern Alps were mainly built by the activity of LGM Alpine glaciers and could be explained as a product of their erosive power in the mountain valleys and their efficiency in evacuate the sediment to the foreland.
Since the glacial withdrawal occurred at the end of LGM
the Alpine rivers incised in their megafans and were more sensitive to the local characteristics of their catchment. In particular the presence of large intramontane lakes, that trapped most part of the sediment.
The main aggrading phase occurred in the megafans during the marine lowstand, while the post-LGM transgression had no important effects until 8 ka cal BP and the marine highstand influenced only the distal sector of the VFP megafans, but not the LP. Thus, in the last glacial cycle the alluvial evolution along Southern Alps was in antiphase in respect to the typical model proposed by sequence stratigraphy.
The coupling between glacial aggradation and interglacial incision occurred also during MIS 6 and MIS 5 and it is likely also for the previous glacial cycles. Thus, along the Alps and in other similar temperate regions, the occurrence of megafans in the Quaternary stratigraphy could be a testimony of the colder phases.
References
Fontana, A., Mozzi, P. and Bondesan, A. (2008) Alluvial megafans in the Venetian–Friulian Plain (north-eastern Italy): Evidence of sedimentary and erosive phases during Late Pleistocene and Holocene. Quaternary International, 189, 71–90.
Fontana, A., Mozzi, P. and Bondesan, A. (2010) Late Pleistocene evolution of the Venetian-Friulian Plain. Rendiconti Lincei, 21 (Suppl.1), 181-196.
Guzzetti, F., Marchetti, M. and Reichenbach, P. (1997) Large alluvial fans in the north-central Po Plain (Northern Italy). Geomorphology 18, 119-136.
Marchetti, M. (2001) Fluvial, fluvioglacial and lacustrine forms and deposits. In: Castiglioni G.B., Pellegrini, G.B. (Eds.), 2001. Illustrative Notes of the Geomorphological Map of the Po Plain. Geografia Fisica Dinamica Quaternaria (Suppl. 7), 73-104
La valutazione della vulnerabilità idraulica in un’area di pianura alluvionale della provincia di Padova, mediante "Multicriteria Evaluation"
No full textMulti Criteria Evaluation of Flood Vulnerability in a Sector of Alluvial Plain
in the Province of Padua. – This paper regards the application of the “Multi Criteria
Evaluation” (MCE) technique to the GIS mapping of the flooding vulnerability of the
alluvial plain near Vighizzolo d’Este, related to overbank flooding of the Agno-Guà-
Frassine-Santa Caterina river. MCE relies on the accurate definition of the factors
which contribute to the final elaboration. The geomorphology and geopedology of the
study area have been defined through DEM elaboration, remote sensing and field survey.
The spatial distribution of buildings and infrastructures, crucial to vulnerability
assessment, has been derived from 1:5.000 topographic maps. The integrated data
elaboration has been carried out using the MCE module of the GIS software
IDRISI32TM. A detailed map of the different degrees of flooding vulnerability in the
study area has been produced
La fotografia aerea obliqua per l'analisi geoarcheologica del territorio della via Annia
No full textLungo il tracciato della via Annia tra Adria e Aquileia sono stati eseguiti numerosi voli aerei dedicati con velivoli da turismo. Le fotografie aeree oblique sono state scattate in diverse condizioni stagionali e di uso del suolo. I crop mark risultano particolarmente efficaci nella detezione di tracce archeologiche sepolte e della paleoidrografia. Le foto oblique sono georiferite con GPS e raddrizzate mediante apposito software. Oltre al tracciato viario antico sono state mappate diverse tipologie di insediamenti e sistemazioni agrarie sepolte
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