794 research outputs found
Cassiano dal Pozzo’s Library and the Historical Works
Cassiano dal Pozzo (1588-1657), accademico dei Lincei e collezionista d’arte, è celebre per il suo “Museo Cartaceo”. Assai meno conosciuta è la sua biblioteca che, con i suoi circa 9.000 volumi, costituisce un caso eccezionale nel panorama delle biblioteche private presenti a Roma nel XVII secolo. Attraverso l’analisi di uno degli inventari pervenutoci, questo articolo intende mostrare come lo studio di una biblioteca apra, in generale, una serie di questioni che riguardano non soltanto la fisionomia, i percorsi e il posizionamento culturale del suo ideatore, ma anche le tendenze, i conflitti, gli interessi, gli sviluppi del contesto politico, sociale e culturale in cui questo genere di impresa si realizza. Nel caso particolare della biblioteca Dal Pozzo, essa è in grado di fornire agli studiosi numerosi elementi di riflessione sulla relazione tra libri e dibattiti culturali del tempo, sulle reti intellettuali connesse a questa relazione a Roma negli anni cruciali del pontificato di Urbano VIII durante i quali l’azione di controllo e di repressione della censura non sembra avere ostacolato del tutto la circolazione di saperi che potessero connettere la città del papa al mondo moderno
Le filiere della distribuzione urbana delle merci a Roma: attori ed efficienza
Le politiche di regolamentazione del traffico urbano merci finora adottate non si sono dimostrate ancora sufficientemente in grado di raggiungere l’obiettivo di migliorare il grado di efficienza privata del sistema distributivo urbano. Di conseguenza, le esternalità negative prodotte da tale traffico, in termini soprattutto di inquinamento e congestione, permangono ancora alte, causando elevati costi sociali. Una delle cause di questo fallimento è la ancora scarsa conoscenza delle caratteristiche organizzative, in termini di numero di attori, di potere decisionale e di obiettivi delle differenti supply chain, il cui anello finale si colloca all’interno delle città. L’obiettivo del lavoro è quello di contribuire a colmare, almeno in parte, questo gap informativo, descrivendo le catene del valore ed i relativi canali di approvvigionamento e di distribuzione relativi alla città di Roma. Si riportano, in particolare, i risultati di 118 interviste dirette effettuate tra novembre e dicembre 2010 a produttori, grossisti e dettaglianti delle dodici macro-filiere maggiormente rappresentative che caratterizzano il commercio urbano nella capitale, focalizzandosi sulla filiera dell’alimentare e su quella di piante e fiori.
A new automated technique for the reconstitution of hydrophobic proteins into planar bilayer membranes. Studies of human recombinant uncoupling protein 1
AbstractElectrophysiological characterisation of the vast number of annotated channel and transport proteins in the postgenomic era would be greatly facilitated by the introduction of rapid and robust methods for the functional incorporation of membrane proteins into defined lipid bilayers. Here, we describe an automated technique for reconstitution of membrane proteins into lipid bilayer membranes, which substantially reduces both the reconstitution time and the amount of protein required for the membrane formation. The method allows the investigation of single protein channels as well as insertion of multiple copies (∼107) into a single bilayer. Despite a comparatively large membrane area (up to 300 μm diameter), the high stability of the membrane permits the application of transmembrane voltages up to 300 mV. This feature is especially important for studies of inner membrane mitochondrial proteins, since they act at potentials up to ∼200 mV under physiological conditions. It is a combination of these advantages that enables the detailed investigation of the minuscule single protein conductances typical for proton transporters. We have applied the new technique for the reconstitution and electrophysiological characterisation of human recombinant uncoupling protein 1, hUCP1, that has been overexpressed in E. coli and purified from inclusion bodies. We demonstrate that hUCP1 activity in the presence of fatty acids is comparable to the activity of UCP1 isolated from brown adipose tissue
Clinical usefulness of detecting galactomannan antigen in the diagnosis of invasive aspergillosis in an University tertiary hospital in Bogota (Colombia) 2010-2012
Objetivo: Determinar la utilidad clínica de la detección antigénica de galactomanano (GM) en pacientes con sospecha de aspergilosis invasora.Materiales y métodos: Se realizó un estudio descriptivo retrospectivo, en el que se evaluaron los pacientes a quienes se les realizó la prueba Platelia® para la detección de GM en suero, entre el 1 de enero de 2010 y el 1 de abril de 2012, que hubiesen sido atendidos en el Hospital Universitario San Ignacio; se recolectaron los datos clínicos, microbiológicos y radiológicos para su posterior análisis.Resultados: Se incluyeron 52 pacientes. Se diagnosticó aspergilosis invasora en 13 pacientes. De estos, el antígeno de GM fue positivo solo en 5 casos, 5 fueron diagnosticados por patología y 3 por clínica y radiología, pues fueron negativos para la patología y para el GM. Se presen-taron 3 casos de falsos positivos y 5 de falsos negativos.Conclusiones: La prueba de GM ha sido un gran avance en la atención médica de los pacien-tes con neoplasia hematológica. Sin embargo, cada hospital debe evaluar la utilidad de esta prueba en sus propias condiciones, a pesar de que nuestros resultados no muestran un ade-cuado rendimiento de la prueba, no es posible generalizar su rendimiento y es necesaria la realización de un estudio prospectivo en nuestro medio.Q3Artículo original31-37Aim: To determine the clinical utility of galactomannan antigen detection in patients with suspect of Invasive Aspergillosis.Tools and methods: A retrospective descriptive study was performed on patients seen in the University Hospital who were tested with the Platelia® Galactomannan (GM), between the 1st of January 2010 and the 1st of April of 2012. Clinical, microbiological and radiological data were collected for further analysis.Results: A total of 52 patients were included in the study. Invasive Aspergillosis (IA) was detec-ted in 13 patients, in whom the GM antigen was positive in only 5 cases, another 5 cases were detected by pathology, and the remaining 3 were detected clinically and by radiology because they were negative for the pathology and the GM. Additionally, 3 cases were false positives and 5 cases were false negative.Conclusions: The GM test has been a big advance in the medical care of patients with hema-tological malignancies. However, each hospital must evaluate the utility of these test in their own conditions, as our results do not show good performance of the test, these results can not be generalized. There is a need to perform a prospective study on this aspect
Steering the magnetic properties of Ni/NiO/CoO core-shell nanoparticle films: The role of core-shell interface versus interparticle interactions
Supported core-shell Ni/NiO/CoO nanoparticle (NP) films were obtained by deposition of preformed and mass-selected Ni NPs on a buffer layer of CoO, followed by a top CoO layer. The resulting NPs have core/shell morphology, with a McKay icosahedral Ni core and a partially crystalline CoO shell. X-ray photoelectron spectroscopy evidenced the presence of a thin NiO layer, which was shown to be between the Ni core and the CoO shell by elemental TEM mapping. CoO and NiO shells with different thickness values were obtained, allowing us to investigate the evolution of the magnetic properties of the NP assemblies as a function of the oxide shell thickness. Both exchange-coupling and magnetostatic interactions significantly contribute to the magnetic behavior of Ni/NiO/CoO NP films. After the Ni/NiO/CoO NPs are cooled in a weak magnetic field, they have blocking temperature higher than room temperature because of strong magnetostatic interactions, which support the formation of a spin-glass-like state below similar to 250 K. Exchange coupling dominates the magnetic behavior after the NPs are cooled in a strong magnetic field. The exchange bias (EB) is in the 0.17-2.35 kOe range and strongly depends on the CoO thickness (0.4-2.7 nm), showing the onset of the EB at the few-nanometer scale. The switching field distribution showed that the EB opposes the magnetization reversal from the direction along the cooling field but it does not significantly ease the opposite process. The EB depends on t(CoO) only for t(NiO) <= 0.5 nm, but when NiO is 0.7 nm thick it strongly interacts with CoO and a large increase of the EB and coercivity is observed
Sunitinib in the therapy of malignant paragangliomas: report on the efficacy in a SDHB mutation carrier and review of the literature
SUMMARY Metastatic pheochromocytomas (PHEOs) and paragangliomas (sPGLs) are rare neural crest-derived tumors with a poor prognosis. About 50% of them are due to germ-line mutations of the SDHB gene. At present, there is no cure for these tumors. Their therapy is palliative and represented by different options among which antiangiogenic drugs, like sunitinib, have been hypothesized to be effective especially in malignant SDHB mutated tumors. We report the effects of sunitinib therapy in a SDHB mutation carrier affected by a malignant sPGL. During 101 weeks of therapy at different doses, sunitinib was able to cause a partial response and then a stable disease for a total of 78 weeks. This favorable response is the longest, out of the 35 so far reported in the literature, registered in a patient treated exclusively with sunitinib but, similarly to the other responses, the effect was limited in time. From our analysis of the scanty data present in the literature, the effect of sunitinib does not seem to be different among wild-type patients and those carrying a cluster 1 germ-line mutation. Sunitinib seems able to slow the disease progression in some patients with malignant PHEO/PGL and therefore may represent a therapeutic option, although randomized controlled studies are needed to assess its efficacy definitively in the treatment of these aggressive tumors
Carrageenans as a New Source of Drugs with Metal Binding Properties
Carrageenans are abundant and safe non-starch polysaccharides exerting their biological effects in living organisms. Apart from their known pro-inflammation properties and some pharmacological activity, carrageenans can also strongly bind and hold metal ions. This property can be used for creation of the new drugs for elimination of metals from the body or targeted delivery of these metal ions for healing purposes. Metal binding activity of different carrageenans in aqueous solutions containing Y3+ or Pb2+ ions was studied in a batch sorption system. The metal uptake by carrageenans is not affected by the change of the pH within the range from 2.0 to 6.0. The rates and binding capacities of carrageenans regarding metal ions were evaluated. The Langmuir, Freundlich and BET sorption models were applied to describe the isotherms and constants, and the sorption isothermal data could be explained well by the Langmuir equation. The results obtained through the study suggest that κ-, ι-, and λ-carrageenans are favorable sorbents. The largest amount of Y3+ and Pb2+ ions are bound by ι-carrageenan. Therefore, it can be concluded that this type of polysaccharide is the more appropriate substance for elaboration of the drugs with high selective metal binding properties
Tunability of exchange bias in Ni@NiO core-shell nanoparticles obtained by sequential layer deposition
Films of magnetic Ni@NiO core-shell nanoparticles (NPs, core diameter d\ua0 45\ua012 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships between shell thickness/morphology, core-shell interface, and magnetic properties. Different values of NiO shell thickness ts could be obtained while keeping the Ni core size fixed, at variance with conventional oxidation procedures where the oxide shell is grown at the expense of the core. Chemical composition, morphology of the as-produced samples and structural features of the Ni/NiO interface were investigated with x-ray photoelectron spectroscopy and microscopy (scanning electron microscopy, transmission electron microscopy) techniques, and related with results from magnetic measurements obtained with a superconducting quantum interference device. The effect of the shell thickness on the magnetic properties could be studied. The exchange bias (EB) field Hbias is small and almost constant for ts up to 1.6 nm; then it rapidly grows, with no sign of saturation. This behavior is clearly related to the morphology of the top NiO layer, and is mostly due to the thickness dependence of the NiO anisotropy constant. The ability to tune the EB effect by varying the thickness of the last NiO layer represents a step towards the rational design and synthesis of core-shell NPs with desired magnetic properties
- …