313 research outputs found
Microelectrode arrays of diamond-insulated graphitic channels for real time detection of exocytotic events from cultured chromaffin cells and slices of adrenal glands
A microstructured graphitic 4x4 multielectrode array was embedded in a single
crystal diamond substrate (4x4 {uG-SCD MEA) for real-time monitoring of
exocytotic events from cultured chromaffin cells and adrenal slices. The
current approach relies on the development of a parallel ion beam lithographic
technique, which assures the time effective fabrication of extended arrays with
reproducible electrode dimensions. The reported device is suitable for
performing amperometric and voltammetric recordings with high sensitivity and
temporal resolution, by simultaneously acquiring data from 16 rectangularly
shaped microelectrodes (20x3.5 um^2) separated by 200 um gaps. Taking advantage
of the array geometry we addressed the following specific issues: i) detect
both the spontaneous and KCl-evoked secretion simultaneously from several
chromaffin cells directly cultured on the device surface, ii) resolve the
waveform of different subsets of exocytotic events, iii) monitoring quantal
secretory events from thin slices of the adrenal gland. The frequency of
spontaneous release was low (0.12 Hz and 0.3 Hz respectively for adrenal slices
and cultured cells) and increased up to 0.9 Hz after stimulation with 30 mM KCl
in cultured cells. The spike amplitude as well as rise and decay time were
comparable with those measured by carbon fiber microelectrodes and allowed to
identify three different subsets of secretory events associated to "full
fusion" events, "kiss and-run" and "kiss-and-stay" exocytosis, confirming that
the device has adequate sensitivity and time resolution for real-time
recordings. The device offers the significant advantage of shortening the time
to collect data by allowing simultaneous recordings from cell populations
either in primary cell cultures or in intact tissues
Failure analysis of fiberglass cover used for photovoltaic plants
Cover boxes with inspection glass are generally used outdoors for photovoltaic systems.Sometimes these boxes break, during normal use. Hightemperature, thermal stress, cyclic stress, and cracking contribute to weakening the polymeric inspection “glass”. The study presents an interdisciplinary analysis to discover the mode of occurrence and causes of the failure. First, the material is accurately characterized. Then its mechanical behavior is characterized in a virtual scenario that reconstructs the real external environment. The goal is to build a new cover with inspection boxes that exhibits superior life cycle behavior when exposed to harsh weather conditions and atmospheric agents. The breaking phenomena of solar panels covering boxes in PMMA (Poly Methyl Methacrylate) are examined. Environmental stress is the main responsible for cracking. Styrene is employed in the polymerization process of Sheet Molding Compound (SMC); the diffusion of this material is the main responsible for cracking. Comprehensive engineering analysis shows how the thermoplastic component fails after being exposed to atmospheric agents. The PMMA “glass” is one of the polymers most sensible to the crazing phenomena
Natural function and structural modification of climacostol, a ciliate secondary metabolite
The review highlights the main results of two decades of research on climacostol (5-[(2Z)-non-2-en-1-yl]benzene-1,3-diol), the resorcinolic lipid produced and used by the ciliated protozoan Climacostomum virens for chemical defense against a wide range of predators, and to assist its carnivorous feeding. After the first studies on the physiological function of climacostol, the compound and some analogues were chemically synthesized, thus allowing us to explore both its effect on different prokaryotic and eukaryotic biological systems, and the role of its relevant structural traits. In particular, the results obtained in the last 10 years indicate climacostol is an effective antimicrobial and anticancer agent, bringing new clues to the attempt to design and synthesize additional novel analogues that can increase or optimize its pharmacological properties
Education and training among Italian postgraduate medical schools in public health: a comparative analysis
Analisi comparativa dei percorsi formativi offerti
dalle Scuole di specializzazione di Igiene e Medicina
Preventiva in Italia
Background: Il percorso formativo dello specialista
in Igiene e Medicina Preventiva dovrebbe garantire
adeguate conoscenze tecnico-scientifiche e professionali
nei campi della medicina preventiva, della promozione
della salute e della programmazione dei servizi sanitari
secondo quanto indicato anche dal DM 285/2005. La
Consulta degli Specializzandi, da sempre coinvolta in
attività di monitoraggio della formazione a livello nazionale,
si prefigge l’obiettivo di valutare l’omogeneità
delle proposte formative tra le diverse sedi italiane, non
solo per segnalare le criticità, ma anche per evidenziarne
le opportunità.
Metodi: Lo studio, di tipo cross-sectional, è stato condotto
mediante la somministrazione di un questionario
semi-strutturato inviato per la compilazione ai rappresentanti
delle 32 le Scuole di Igiene e Medicina Preventiva
italiane. Lo strumento di valutazione è costituito da
quattro sezioni: informazioni generali, attività formativa
universitaria, attività formativa extra-universitaria, attività
formativa intersettoriale. L’indagine è stata svolta
nel periodo tra marzo e maggio 2013 ed è stata prodotta
un’analisi descrittiva dei dati ottenuti.
Risultati: Il questionario è stato compilato da 28
Scuole su 32 (tasso di risposta 88%), distribuite su
tutto il territorio nazionale. Il numero di medici in
formazione varia tra 7 e 31 e il rapporto tra docenti del
settore scientifico-disciplinare di interesse e i discenti è
compreso tra 0,2 e 2.
Per quanto riguarda la didattica, solo in 4 Scuole
si effettuano tutti i corsi previsti dal DM. La maggior
parte delle sedi svolge almeno il 75% dei corsi previsti,
ma esistono sedi in cui il numero di corsi è inferiore al
50%. La maggior parte delle Scuole svolge più del 60%
delle attività professionalizzanti essenziali secondo
il decreto, ma 2 Scuole non arrivano al 50%. Tutte le
Scuole prevedono un tirocinio di 6-12 mesi in ASL,
affiancando principalmente attività del Dipartimento di
Prevenzione.
Ovunque è previsto un periodo in Direzione Medica
Ospedaliera, mentre le Strutture Riabilitative rientrano
raramente nella rete formativa. Nella maggioranza delle
Scuole è possibile frequentare aziende con rischio biologico
oppure seguire simili attività nei Servizi dedicati della
ASL. Molte Scuole, infine, consentono di frequentare
diverse strutture territoriali (Agenzia di Controllo delle
Acque), regionali (Assessorati) o nazionali (Ministero,
Istituto Superiore di Sanità); in alcuni casi si tratta di
Università gemellate e Istituti di Ricerca.
Conclusioni: Nonostante il DM 285/2005 indichi quali
siano le fondamenta della sanità pubblica, la flessibilità
nella scelta formativa è vista come requisito essenziale
per ottimizzare le risorse e contestualizzare l’adeguata
formazione del medico in formazione specialistica in
Igiene e Medicina Preventiva. La maggior parte delle
Scuole di Specializzazione italiane dovrebbe però prevedere
lo svolgimento della quasi totalità delle attività
formative previste, al fine di non creare disuguaglianze
formative tra gli specializzandi. Infine, considerato che
la sanità pubblica è una disciplina in continuo divenire,
il DM del 2005 andrebbe rivisitato tenendo in considerazione
la flessibilità della formazione ed i continui cambiamenti
dei bisogni di salute essenziali della popolazione.
Inoltre, nel processo di rivisitazione dei bisogni formativi
dei medici in formazione specialistica, dovrebbero essere
coinvolti anche i discenti al fine di rafforzare il potere e
l’efficacia dell’insegnamento.Background The postgraduate medical Schools in Public Health (locally known as School of Hygiene and Preventive Medicine) should ensure adequate scientific and technical knowledge and professional skills in preventive medicine, health promotion and healthcare planning as provided by Ministerial Decree 285/2005. The Italian Committee of Medical Residents in Hygiene, Preventive Medicine and Public Health of the Italian Society of Hygiene, Public Health and Preventive Medicine - S.It.I. (Consulta Nazionale dei medici in formazione specialistica S.It.I.) has always been engaged in monitoring activities on public health teaching, guaranteeing the homogeneity of educational proposals among all national Schools in Public Health. The purpose of this study is to provide a 'snapshot' of public health education and training in Italy and to identify the improvement actions needed for implementing an innovative and homogeneous public health training. Methods: A cross-sectional study was carried out over a period of three months (March to May 2013). A self-administered questionnaire was e-mailed to local Committee’s delegates of all 32 postgraduate medical Schools in Public Health in Italy. The questionnaire was structured in four sections: general information, University education and training, extra-University training, interdisciplinary activities. The majority of local Committee’s delegates have agreed to be enrolled in the survey.
Results: A total of 28 questionnaires were returned (88% response rate). The number of residents in each Italian School in Public Health ranged from 7 to 31. The distribution of professors in relation to residents is not similar for each University Schools. The ratio professors/residents spanning from 0.2 to 2.
About teaching, only 4 University Schools offered all courses requested by Ministerial Decree 285/2005. Most of them offered at least 75% of the requested courses, but there were Schools in which the courses were less than 50%. The vast majority of schools held more than 60% of the qualifying activities considered essential according to the Decree, while 2 Schools were below 50%. All Schools required an internship of 6-12 months in local health authority offices (ASL), mainly concerning the Department of Prevention activities.
In all Schools a period of stay in a Hospital Medical Direction was scheduled, while professional activities at Residential care homes were very rarely included in training programmes. Many Schools allowed residents to attend companies with biological hazard or to follow similar activities in dedicated services of ASL.
Finally, in the majority of Schools, a training period in various local (Service for Water Control), regional (Departments) or national (Ministry, National Institute of Health) health facilities was contemplated and, in some cases, also in other Universities or Research Institutes.
Conclusions: Although the Ministerial Decree indicates the essential milestones of the public health education, flexibility is seen as an important element in order to optimize resources and contextualize the adequate education of residents. In any case, at least regarding public health courses, the majority of University education and extra-University training activities should be carried out by all Schools. In order to obtain shared knowledge and skills, the Ministerial Decree should be revised taking into account flexibility and changing as intrinsic characteristics of public health profession and learners should be involved in the reform to strengthening the role of public health teachin
Nanodiamonds-induced effects on neuronal firing of mouse hippocampal microcircuits
Fluorescent nanodiamonds (FND) are carbon-based nanomaterials that can
efficiently incorporate optically active photoluminescent centers such as the
nitrogen-vacancy complex, thus making them promising candidates as optical
biolabels and drug-delivery agents. FNDs exhibit bright fluorescence without
photobleaching combined with high uptake rate and low cytotoxicity. Focusing on
FNDs interference with neuronal function, here we examined their effect on
cultured hippocampal neurons, monitoring the whole network development as well
as the electrophysiological properties of single neurons. We observed that FNDs
drastically decreased the frequency of inhibitory (from 1.81 Hz to 0.86 Hz) and
excitatory (from 1.61 Hz to 0.68 Hz) miniature postsynaptic currents, and
consistently reduced action potential (AP) firing frequency (by 36%), as
measured by microelectrode arrays. On the contrary, bursts synchronization was
preserved, as well as the amplitude of spontaneous inhibitory and excitatory
events. Current-clamp recordings revealed that the ratio of neurons responding
with AP trains of high-frequency (fast-spiking) versus neurons responding with
trains of low-frequency (slow-spiking) was unaltered, suggesting that FNDs
exerted a comparable action on neuronal subpopulations. At the single cell
level, rapid onset of the somatic AP ("kink") was drastically reduced in
FND-treated neurons, suggesting a reduced contribution of axonal and dendritic
components while preserving neuronal excitability.Comment: 34 pages, 9 figure
Macro Minerals and Trace Elements in Milk of Dairy Buffaloes and Cows Reared in Mediterranean Areas
Aim of this study was to evaluate the differences in Ca, P, K, Na, Mg, Zn, Fe, Cu, Mn, Se, Mo, Co, Li, B, Ti, Rb, and Sr concentrations in milk from buffaloes and cows reared in the same farm in Mediterranean areas and fed diets including the same ingredients. Individual milk samples were obtained from 32 Mediterranean buffaloes and 29 Italian Friesian cows and samples of milk, dietary ingredients and drinking water were analyzed for the investigated chemical elements by inductively coupled plasma-mass spectrometry. Data about milk element concentrations were processed by one-way analysis of variance. Buffalo milk contains higher concentrations of Ca, P, Mg, Zn, Fe, Cu, B, Ti, and Sr, and lower concentrations of K, Na, Mo, Li, and Rb compared to cow milk, whereas milk from both species contains similar concentrations of Mn, Se, and Co. The concentrations of the investigated elements in the diet were similar for both species and the differences observed between buffalo and cow milk were not dependent on environmental factors
Distribution of selected trace elements in the major fractions of donkey milk
The aim of this study was to evaluate the concentrations of Zn, Cu, Mn, Se, Mo, Co, Li, B, Ti, Cr, Rb, Sr, Cd, and Pb in donkey milk and their distribution in major milk fractions (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were provided by 16 clinically healthy lactating donkeys. Subsequent centrifugation, ultracentrifugation, and ultrafiltration were carried out to remove fat, casein, and whey proteins to obtain skim milk, a supernatant whey fraction, and the aqueous phase of milk, respectively. Concentrations of the elements were measured in whole milk and fractions by inductively coupled plasma-mass spectrometry, and the concentrations associated with fat, casein, and whey proteins were then calculated. The effect of removal of fat, casein, and whey proteins was determined by repeated-measures ANOVA. The fat fraction of donkey milk carried a small (∼4.5% to 13.5%) but significant proportion of Mo, Co, Ti, Cr, and Sr. The casein fraction in donkey milk carried almost all milk Zn, a majority of Cu and Mn, and most of Mo, Ti, and Sr. Relevant proportions, between 20% and 36%, of Se, Co, and Cr were also associated with caseins. The majority of Se, Co, Li, B, Cr, and Rb, and relevant proportions of Mn, Mo, Ti, and Sr were found in soluble form (ultracentrifuged samples) and distributed between whey proteins and the aqueous phase of milk (ultrafiltered samples). Whey proteins in donkey milk carried the majority of milk Se and Co. All Li and B was present in the aqueous phase of milk, which also contained most Rb and Cr, and 17% to 42% of Mn, Se, Mo, Co, Ti, and Sr
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