1,720,997 research outputs found
Tajikistan, la Valle dello Yaghnob
No full textIl video documentario della seconda missione in Tajikistan racconta le esperienze del gruppo di ricerca diretto da Antonio Panaino riprendendo non solo i vari ricercatori durante i lavori sul campo ma illustra anche la vita ed i costumi della popolazione yaghnobi. Il documentario è stato premiato con il terzo posto al concorso "premio Chatwin" per documentari non professionali nella categoria "amore senza frontiere" volontariato nel mondo
DESIGN, SYNTHESIS AND CHARACTERIZATION OF MAGNETIC BIO-INORGANIC NANOSYSTEMS WITH THERANOSTIC FEATURES.
Full text linkThe aim of my PhD project is to obtain immune nanosystems having, at the same time, diagnostic and therapeutic functions.
To combine these applications, our nanosystems will be constituted by magnetic nanoparticles linked to an antibody fragment. Magnetic nanoparticles , (I will synthesize cubic ferrites mainly of iron, but also of other transition metals such as cobalt), give us both diagnostic properties, because they are already used as contrast agents in magnetic resonance imaging (MRI), and therapeutic properties, because they could be used in hypertemia experiments for cancer treatment. Furthermore they allow us to monitor the response to therapy.
Instead the functionalization of magnetic nanoparticles with a specific antibody fragment (in particular we will start with the fragment of Trastuzumab, a monoclonal antibody that binds to human epidermal growth factor receptor 2 (HER2) )first provides us an active targeting. Indeed HER2 receptor is overexpressed in 20-30% of breast cancers and also in some types of adenocarcinoma of the stomach or gastro-oesophageal junction. Then Trastuzumab give us other therapeutic properties because, with different mechanisms of action, modifies cellular proliferation. So we want to overcame the limitation of traditional chemotherapy, improving the treatment specificity and dramatically reducing toxicity and unspecific side effects.
We will start to synthesize magnetic nanoparticles by solvothermal methods, that is , a high-temperature decomposition of metal precursors in non-coordinating solvents and in the presence of surfactants . But in order to obtain nanoparticles water soluble, native surfactants like oleic acid will be exchanged with suitable linker. Particular attention will be given to the synthesis of the latter.
Hydrophilic linker will be formed by: a catechol moiety to anchor surfactant to magnetic nanoparticles, a maleimide group able to reacting with free thiol group present on the Trastuzumab antibody fragment and a long polyethylene glycol chain (with molecular weight around 5000 KDa) to enhance water solubility and stability. PEG chain also provides magnetic nanoparticles of a “stealth effect” .They are less recognised by circulating plasma proteins opsonins which adsorb onto their surface and then are removed from the blood by the circulating monocytes and fixed macrophages. So the plasma half-life of these nanoparticles is increased together with the probability of arriving to desided target.
We have to characterize these immuno-nanosystems under different aspects.
The magnetic NPs will be analyzed:- by transmission electron microscopy (TEM) to study shape, dimensions and chemical composition;
- by SQUID (Superconducting Quantum Interference Devices )magnetometry, to measure the magnetical properties
- by measurements of proton relaxivity and specific absortion rate (SAR) to quantify capacity of NPs to be used as contrast agents and mediators for hyperthermia
We will also study water stability of immune nanoparticles in function of time, pH and temperature with DLS analysis.
Afterwards we will investigate in vitro toxicity of immune-nanosystems after their uptake from cells overexpressing HER2 receptor
Intramolecular nitrilimine cycloadditions to the thiophene and the furan rings
No full textThe dipolarophilic behavior of furan and thiophene rings have been exploited in the intramol. cycloaddns. of nitrilimines. These labile intermediates were generated from the corresponding hydrazonoyl chlorides by treatment with silver carbonate. The extent of formation of tricyclic cycloadducts was strongly dependent on the substitution pattern of the heteroarom. ring, thus reflecting the HOMO-dipole controlled nature of the cycloaddn
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Colloidal stability of iron oxide nanocrystals coated with a PEG-based tetra-catechol surfactant
No full textLong-term colloidal stability of magnetic iron oxide nanoparticles (NPs) is an important goal that has not yet been fully achieved. To make an advance in our understanding of the colloidal stability of iron oxide NPs in aqueous media, we prepared NPs comprising a monodisperse (13 nm) iron oxide core coated with a PEG-based (PEG: polyethyleneglycol) surfactant. This consists of a methoxy-terminated PEG chain (MW = 5000 Da) bearing four catechol groups via a diethylenetriamine linker. The surfactant was grafted onto the nanocrystals by ligand exchange monitored by infrared spectroscopy. The colloidal stability of these nanoparticles was probed by monitoring the time evolution of the Z-average intensity-weighted radius Rh and volume-weighted size distribution Pv obtained from analysis of dynamic light scattering data. The nanoparticles showed no sign of aggregation for four months in deionized water at room temperature and also when subjected to thermal cycling between 25 and 75 °C. In 0.01 M PBS (phosphate buffered saline), aggregation (if any) is slow and partial; after 66 h, about 50% of NPs have not aggregated. Aggregation is more effective in 0.15 M NH4AcO buffer, where isolated particles are not observed after 66 h, and especially in acidic NH4AcO/AcOH buffer, where aggregation is complete within 1 h and precipitation is observed. The differing stability of the NPs in the above aqueous media is closely related to their ζ potential
Sostenibilità, produttività e benessere delle bovine da latte: il ruolo della tecnologia
Full text linkNegli allevamenti da latte italiani è in corso unna modernizzazione con l'introduzione di sensoristica e sistemi automatici
per la gestione del bestiame
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Failure of automatic control of ventilation (Ondine's curse) associated with viral encephalitis of the brainstem: A clinicopathologic study of one case
No full text[No abstract available
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