644 research outputs found
Community Structure of Terrestrial Invertebrates Inhabiting a Tidal Marsh Islet in the Mediterranean Sea (Gulf of Gabes, Tunisia)
The composition of the terrestrial arthropod community of a tidal marsh islet in the Gulf of Gabes (Tunisia) was studied during two seasons (spring, autumn). The study was conducted on a small islet located in an area where the highest tidal excursions of the Mediterranean occur. Standard trapping methods (pitfall traps, mobile cages) were used to evaluate specie richness and abundance in different areas of the islet. Diversity indices were calculated for coleopterans and isopods alone. The structure of the arthropod community varied a great deal from one season to the other and differences were found when seaward areas were compared with landward ones. El Bessila presented a particularly rich beetle community whereas only few isopod species occurred. The moderately high diversity levels found for the beetle indicate the influence of the high tidal excursions in modelling the structure of the community
Deamidation at Asparagine and Glutamine As a Major Modification upon Deterioration/Aging of Proteinaceous Binders in MuralPaintings
Proteomic strategies are herein proved to be a
complementary approach to the well established amino acid
composition analysis for the characterization of the aging and
deterioration phenomena occurring to proteinaceous materials
in works-of-art. Amino acid analyses on several samples demonstrated
that proteins in the frescoes from the Camposanto
Monumentale in Pisa are deteriorated as revealed by the
decrease in Met, Lys, and Tyr content and by the presence in
all the samples of amino malonic acid as a result of Ser, Phe, and
Cys oxidation. Proteomic analysis identified deamidation at Asn
and Gln as a further major event occurred. This work paves the
way to the exploitation of proteomic strategies for the investigation
of the molecular effects of aging and deterioration in
historical objects. Results show that proteomic searches for
deamidation by liquid chromatography-tandem mass spectrometry
(LC-MS/MS) could constitute a routine analysis for paintings or any artistic and historic objects where proteins are present.
Peptides that can be used as molecular markers when casein is present were identified
Hypoproteic diet in patients' community: reports from University of Pisa
Nutrition is considered by the National Health Authorities as part of the clinical care process. In this perspective, the catering service of a hospital represents a powerful therapeutic and educational aid for the in-patients.The catering service of our University Hospital in Pisa is based on a collection of standardized diets with indications concerning the type of patient which they are addressed. The present paper deals with our experience in this field, and in particular with the diets for renal patients.The so called "special" diets, such as low protein (0.6 g / kg b. w. / day) low phosphorus diet, the low protein (0.7 g / kg b.w./ day) vegetarian diet and the very low protein (0.3 g / kg b. w./day) low phosphorus diet are prescribed by the doctors and developed by the dietician for the individual patient.Since its preparation, the low-protein diets have several critical points, namely processing - packaging and distribution of the diet, no customization, the low protein artificial foods).In order t..
A mass spectrometric study on tannin degradation within dyed woolen yarns
Natural tannins from various plants have been used throughout human history in textile dyeing, often as mordant dyes. The ageing behavior of these dyes is a challenge in conservation science, requiring a thorough knowledge of the textile–mordant-dye system. In this work, we analyzed reference wool yarns dyed with natural tannins from oak gallnuts, walnut (Juglans regia), and catechu (Acacia catechu), after artificial ageing. To gain insights on the composition of the dyestuffs and on how they aged, an analytical procedure based on extraction with Na2EDTA/DMF (ethylenediaminetetraacetic acid/dimethylformamide) and high-performance liquid chromatography (HPLC) analysis using high-resolution mass spectrometry detection was used. Since conventional reversed-phase (RP) columns usually show poor retention efficiency of highly polar compounds such as tannins, an RP-amide embedded polar group stationary phase was used to achieve optimal retention of the most polar compounds. Tannins from oak gallnuts showed little degradation after ageing, while a significant increase in the content of hydroxybenzoic acids was observed for tannins from walnut and catechu. Finally, the analytical procedure was applied to characterize the tannin dyes in historical tapestries from the 15th to 16th century, and the results were discussed in comparison with the reference yarns
The analysis of the Saltzman Collection of Peruvian dyes by high performance liquid chromatography and ambient ionisation mass spectrometry
Yarn samples from the Saltzman Collection of Peruvian dyes were characterized by several different analytical techniques: high performance liquid chromatography with both diode array detection (HPLC-DAD) and electrospray ionisation with tandem mass spectrometry (HPLC-ESI-Q-ToF), direct analysis in real time (DART) mass spectrometry and paper spray mass spectrometry. This report serves primarily as a database of chemical information about the colorants in these dye materials for those studying ancient South American textiles and their colorants. We also provide a comparison of the results obtained by currently widespread HPLC techniques with those of two different ambient ionisation direct mass spectrometry methods to highlight the advantages and disadvantages of these approaches
Microwave-assisted preparation of multi principal element alloys by powder metallurgy approach
According to literature, the synthetic route to produce High entropy alloys (HEAs) should guarantee short alloying time, efficient cooling and capability to operate in controlled atmosphere. Such conditions can be achieved using high frequency electromagnetic fields, like microwave heating. In this work FeCoNiCrAl and FeCoNiCuAl, both equiatomic and reinforced by the 10% wt. of SiC were prepared by microwave assisted techniques. Results show that direct microwave heating of the powder precursors occurs, until the ignition conditions are reached. The temperature and duration of the microwave-assisted process result much lower than other conventional powder metallurgy routes, but at the cost of a higher residual porosity. Sample characterization confirmed that the powder metallurgy approach is suitable to retain the shape of the load imparted during forming by uniaxial pressing. The homogeneity of the samples resulted in being good in all cases, without the dendritic segregation typically occurring by liquid phase processing. © 2017 European Powder Metallurgy Association (EPMA
Covid-19 and UNIMORE students: how the emergency changes the study and the university experience
The research report presents the results of the online survey conducted by the University of Modena and Reggio Emilia on the living and study conditions of students in the period 8 April - 2 May 2020. The online survey was answered by 20% of students: an adequate participation rate to capture some significant differences between courses of study. The aim of the survey is to overcome the Covid-19 emergency with greater awareness, analysing the living and study conditions of the students and looking for the most useful tools for inclusive teaching and study that contribute to giving each student the possibility to proceed in their own study and life path in the best possible way. The questionnaire, the survey tools and the results that emerge from the multivariate analysis are presented, both for the closed-answer questions and for the openended questions, on which textual analysis techniques have been applied. The different tools and methods are presented to emphasize the specificity of the dataset, which presents a different level of variability of the answers in the different thematic areas. The report concludes with a series of considerations that we offer to the Unimore community to support the discussion on what we have learned and continue to learn thanks to the voice of the students. It is now clear that the exit from the emergency will be a gradual process. The students' point of view, which we gather from this survey, will be really valuable to plan next year's educational activities and services for students, in order to offer a high quality teaching that responds to different needs and study contexts. Further developments of the analysis may concern other in-depth studies on specific teaching methods (distance and in-presence) and on the evaluation of the living and working conditions of teaching and technical-administrative staff. The basic idea is to read, through the Covid-19 emergency lens, the essential dimensions to improve the quality of teaching highlighted by the empirical survey
La dieta ipoproteica nella ristorazione collettiva: l'esperienza dell'Azienda Ospedaliero-Universitaria Pisana
La nutrizione è considerata dalla legislazione sanitaria corrente parte integrante della prevenzione e terapia clinica, e quindi del processo assistenziale. In questa ottica il servizio di ristorazione di un ospedale rappresenta un potente ausilio terapeutico ed educazionale.
Il servizio di ristorazione della nostra Azienda Ospedaliera-Universitaria Pisana si basa sul Dietetico, una raccolta di diete standardizzate a composizione bromatologica definita, nel quale vengono indicate anche le finalità e le caratteristiche dei pazienti a cui si rivolge. Questo articolo riporta la nostra esperienza in questo settore, con particolare riguardo alle diete speciali per i pazienti nefropatici.
Le diete speciali, come la dieta ipoproteica (0.6 g/kg p.c./die) ipofosforica, la dieta ipoproteica (0.7 g/kg p.c./ die) vegetariana e la dieta fortemente ipoproteica (0.3 g/kg p.c./die) ipofosforica sono prescritte dal medico, elaborate dal dietista e formulate per il singolo paziente. Sin dalla sua preparazione la dieta speciale ipoproteica presenta diversi punti critici (elaborazione-confezionamento e distribuzione della dieta, mancata personaliz-zazione, prodotti artificiali aproteici). Allo scopo di migliorare il servizio dietetico abbiamo rilevato l'effettivo consumo e la gradevolezza dei pasti speciali ipoproteici distribuiti durante la degenza mediante la compilazione di due schede consegnate ai pazienti nel corso della degenza. Nel complesso i risultati indicano una buona accettazione delle diete da parte dei pazienti, ma con un ridotto consumo in particolare riguardante il pane aproteico
Colourants on the wall paintings of a mediÓ•val fortress at the mount Sofeh in Isfahan, central Iran
Colourants on the twelfth century wall paintings excavated at the fortress located on the mount Sofeh in Isfahan, central Iran, were analysed using micro X-ray fluorescence (µ-XRF), micro Raman spectroscopy (µ-Raman) and high-performance liquid chromatography coupled to electrospray ionization quadropole time-of-flight (HPLC-ESI-Q-TOF). The results of the analyses showed that gypsum, atacamite, carbon black, orpiment and ultramarine blue were used as white, green, black, yellow and blue pigments, respectively. Moreover, three red colourants including red lead, red vermilion and madder red were identified in the wall paintings. Furthermore, possible sources for the colourants are discussed
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