228 research outputs found
Internazionalizzazione e digitalizzazione delle PMI italiane.
Le piccole e medie imprese in Italia rappresentano oltre il 99% del tessuto economico industriale. Esse sono caratterizzate da una governance aziendale in cui prevale la tradizione familiare, dallo stretto contatto con il territorio (aspetto che ha dato vita al fenomeno del distretto industriale ed è stato l’humus per lo sviluppo del cosiddetto “quarto capitalismo”), dalla specializzazione nei settori della manifattura leggera (agro- alimentare, beni di consumo per la persona e la casa, meccanica leggera). Nonostante molti autori vedano la prevalenza delle piccole imprese come un vincolo alla crescita economica nazionale, è da evidenziare che il “made in Italy” è rappresentato nel mondo proprio dalla piccola dimensione industriale e dai distretti. L’evoluzione tecnologica e competitiva comporta la necessità per le aziende di indirizzarsi verso il mondo esterno con forme più o meno forti di internazionalizzazione. Dopo aver analizzato i modelli teorici di commercio internazionale e le forme di investimento diretto estero, la tesi prosegue analizzando l’attuale contesto economico. L’emergere di nuovi mercati di sbocco, la rapida crescita di paesi “in via di sviluppo” e l’intensificarsi della competizione internazionale costringono le imprese a pianificare le strategie di innovazione ed espansione internazionale. Internet e in generale il Web possono rappresentare uno strumento di crescita per molte piccole e medie imprese, poiché la digitalizzazione abbatte i costi d’entrata in molti mercati (specialmente quelli “elettronici”); allo stesso tempo, l’esperienza internazionale e distributiva delle medie e grandi imprese può costituire un vantaggio competitivo rilevante e garantire loro il mantenimento di elevate quote di mercato
A catalogue of nuclear stellar velocity dispersions of nearby galaxies from \u2009H\u3b1 STIS spectra to constrain supermassive black hole masses
We present new measurements for the nuclear stellar velocity dispersion \u3c3* within sub-arcsecond apertures for 28 nearby galaxies. Our data consist of Space Telescope Imaging Spectrograph (STIS) long-slit spectra obtained with the G750M grating centred on the H\u3b1 spectral range. We fit the spectra using a library of single stellar population models and Gaussian emission lines, while constraining in most cases the stellar-population content from an initial fit to G430L STIS spectra. We illustrate how these \u3c3* measurements can be useful for constraining the mass M\u2022 of supermassive black holes (SBHs) by concentrating on the cases of the lenticular galaxies NGC 4435 and NGC 4459. These are characterized by similar ground-based half-light radii stellar velocity dispersion \u3c3e values but remarkably different M\u2022 as obtained from modelling their central ionized-gas kinematics, where NGC 4435 appears to host a significantly undermassive SBH compared to what is expected from the M\u2022 - \u3c3e relation. For both galaxies, we build Jeans axisymmetric dynamical models to match the ground-based stellar kinematics obtained with Spectrographic Areal Unit for Research on Optical Nebulae integral-field spectrograph, including an SBH with M\u2022 value as predicted by the M\u2022 - \u3c3e relation and using high-resolution HST images taken with the Advanced Camera for Surveys to construct the stellar-mass model. By mimicking the HST observing conditions we use such reference models to make a prediction for the nuclear \u3c3* value. Whereas this was found to agree with our nuclear \u3c3* measurement for NGC 4459, for NGC 4435 the observed \u3c3* is remarkably smaller than the predicted one, which further suggests that this galaxy could host an undermassive SBH
Fad diets and their effect on urinary stone formation
Abstract: The influence of unhealthy dietary habits on urinary stone formation has been widely recognized
in literature. Dietary advice is indeed the cornerstone prescription for prevention of nephrolithiasis as well.
However, only a small amount of medical literature has addressed the influence of popular or fad diets, often
self-prescribed for the management of obesity and overweight or for cultural beliefs, on the risk of kidney
stones. Thereby in this paper we analyze the current knowledge on the effects of some popular diets on
overall lithogenic risk. High-protein diets, like Dukan diet, raise some concerns, since animal proteins are
able to increase urinary calcium and to decrease urinary citrate excretion, thus leading to a high overall
lithogenic risk. Low-carbohydrate diets, like Atkins diet or zone diet, may have a protective role against
kidney stone formation, but there are also evidences stating that this dietary approach may rise calciuria
and decrease citraturia, since it is generally associated to a relatively high intake of animal proteins. Vegan
diet can be harmful for urinary stone disease, especially for the risk of hyperuricemia and micronutrient
deficiencies, even if only few studies have addressed this specific matter. On the other side, the benefits
of a lacto-ovo-vegetarian diet on kidney stone prevention have been largely emphasized, provided that
the intake of calcium and oxalate is balanced. Traditional Mediterranean diet should exert a protective
effect on nephrolithiasis as well, even if specific studies have not been carried out yet. High phytate and
antioxidant content of this diet have however demonstrated to be beneficial in preventing the formation
of new or recurrent calculi. Anyway, at the current state of knowledge, the most effective dietary approach
to prevent kidney stone disease is a mild animal protein restriction, a balanced intake of carbohydrates
and fats and a high intake of fruit and vegetables. Other fundamental aspects, which are often neglected in
fad diets, are a normal intake of milk and dairy products and salt restriction. All these nutritional aspects
should be greatly taken into account when patients who are willing to undergo fad or commercial diets ask
for dietary advice
Kinematic and stellar population properties of the counter-rotating components in the S0 galaxy NGC 1366
Context. Many disk galaxies host two extended stellar components that rotate in opposite directions. The analysis of the stellar populations of the counter-rotating components provides constraints on the environmental and internal processes that drive their formation. Aims. The S0 NGC 1366 in the Fornax cluster is known to host a stellar component that is kinematically decoupled from the main body of the galaxy. Here we successfully separated the two counter-rotating stellar components to independently measure the kinematics and properties of their stellar populations. Methods. We performed a spectroscopic decomposition of the spectrum obtained along the galaxy major axis and separated the relative contribution of the two counter-rotating stellar components and of the ionized-gas component. We measured the line-strength indices of the two counter-rotating stellar components and modeled each of them with single stellar population models that account for the \u3b1/Fe overabundance. Results. We found that the counter-rotating stellar component is younger, has nearly the same metallicity, and is less \u3b1/Fe enhanced than the corotating component. Unlike most of the counter-rotating galaxies, the ionized gas detected in NGC 1366 is neither associated with the counter-rotating stellar component nor with the main galaxy body. On the contrary, it has a disordered distribution and a disturbed kinematics with multiple velocity components observed along the minor axis of the galaxy. Conclusions. The different properties of the counter-rotating stellar components and the kinematic peculiarities of the ionized gas suggest that NGC 1366 is at an intermediate stage of the acquisition process, building the counter-rotating components with some gas clouds still falling onto the galaxy. \ua9 ESO 2017
Attitudes of Healthcare Workers toward Influenza Vaccination in the COVID-19 Era
none8Sani, Tommaso; Morelli, Ilaria; Sarti, Donatella; Tassinari, Giovanni; Capalbo, Maria; Espinosa, Emma; Gasperini, Beatrice; Prospero, EmiliaSani, Tommaso; Morelli, Ilaria; Sarti, Donatella; Tassinari, Giovanni; Capalbo, Maria; Espinosa, Emma; Gasperini, Beatrice; Prospero, Emili
Role of the Metal Center in the Modulation of the Aggregation Process of Amyloid Model Systems by Square Planar Complexes Bearing 2-(2'-pyridyl)benzimidazole Ligands
The effect of analogue Pd(II)-, Pt(II)-, and Au(III) compounds featuring 2-(2'-pyridyl)benzimidazole on the aggregation propensity of amyloid-like peptides derived from Aβ and from the C-terminal domain of nucleophosmin 1 was investigated. Kinetic profiles of aggregation were evaluated using thioflavin binding assays, whereas the interactions of the compounds with the peptides were studied by UV-Vis absorption spectroscopy and electrospray ionization mass spectrometry. The results indicate that the compounds modulate the aggregation of the investigated peptides using different mechanisms, suggesting that the reactivity of the metal center and the physicochemical properties of the metals (rather than those of the ligands and the geometry of the metal compounds) play a crucial role in determining the anti-aggregation properties
An interaction study in mammalian cells demonstrates weak binding of HSPB2 to BAG3, which is regulated by HSPB3 and abrogated by HSPB8
The ten mammalian small heat shock proteins (sHSPs/HSPBs) show a different expression profile, although the majority of them are abundant in skeletal and cardiac muscles. HSPBs form hetero-oligomers and homo-oligomers by interacting together and complexes containing, e.g., HSPB2/HSPB3 or HSPB1/HSPB5 have been documented in mammalian cells and muscles. Moreover, HSPB8 associates with the Hsc70/Hsp70 co-chaperone BAG3, in mammalian, skeletal, and cardiac muscle cells. Interaction of HSPB8 with BAG3 regulates its stability and function. Weak association of HSPB5 and HSPB6 with BAG3 has been also reported upon overexpression in cells, supporting the idea that BAG3 might indirectly modulate the function of several HSPBs. However, it is yet unknown whether other HSPBs highly expressed in muscles such as HSPB2 and HSPB3 also bind to BAG3. Here, we report that in mammalian cells, upon overexpression, HSPB2 binds to BAG3 with an affinity weaker than HSPB8. HSPB2 competes with HSPB8 for binding to BAG3. In contrast, HSPB3 negatively regulates HSPB2 association with BAG3. In human myoblasts that express HSPB2, HSPB3, HSPB8, and BAG3, the latter interacts selectively with HSPB8. Combining these data, it supports the interpretation that HSPB8-BAG3 is the preferred interaction
Comorbidities and disease severity as risk factors for carbapenem-resistant Klebsiella pneumoniae colonization: report of an experience in an internal medicine unit
Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an emerging multidrug-resistant nosocomial pathogen, spreading to hospitalized elderly patients. Risk factors in this setting are unclear. Our aims were to explore the contribution of multi-morbidity and disease severity in the onset of CRKP colonization/infection, and to describe changes in epidemiology after the institution of quarantine-ward managed by staff-cohorting
Controlled Release of 5-FU from Chi–DHA Nanoparticles Synthetized with Ionic Gelation Technique: Evaluation of Release Profile Kinetics and Cytotoxicity Effect
The ionic gelation technique allows us to obtain nanoparticles able to function as carriers for hydrophobic anticancer drugs, such as 5-fluoruracil (5-FU). In this study, reticulated chitosan– docosahexaenoic acid (Chi–DHAr) nanoparticles were synthesized by using a chemical reaction between amine groups of chitosan (Chi) and carboxylic acids of docosahexaenoic acid (DHA) and the presence of a link between Chi and DHA was confirmed by FT-IR, while the size and morphology of the obtained Chi-DHAr nanoparticles was evaluated with dynamic light scattering (DLS) and scanning electron microscopy (SEM), respectively. Drug-loading content (DLC) and drug-loading efficiency (DLE) of 5-FU in Chi-DHAr nanoparticles were 33.74 ± 0.19% and 7.9 ± 0.26%, respectively, while in the non-functionalized nanoparticles (Chir + 5FU), DLC, and DLE were in the ranges of 23.73 ± 0.14%, 5.62%, and 0.23%, respectively. The in vitro release profile, performed in phosphate buffer saline (PBS, pH 7.4) at 37 °C, indicated that the synthetized Chi–DHAr nanoparticles provided a sustained release of 5-FU. Based on the obtained regression coefficient value (R2), the first order kinetic model provided the best fit for both Chir and Chi-DHAr nanoparticles. Finally, cytotoxicity studies of chitosan, 5-FU, Chir, Chir + 5-FU, Chi-DHAr, and Chi-DHAr + 5-FU nanoparticles were conducted. Overall, Chi-DHAr nanoparticles proved to be much more biocompatible than Chir nanoparticles while retaining the ability to release the drug with high efficiency, especially towards specific types of cancerous cells
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