1,721,031 research outputs found
Utilizzo e realizzazione di prodotti multimediali nell'insegnamento dell'educazione fisica
No full textDichloro[hydrotris(l-pyrazolyl)borato]sulfidotechnetium-(V): The First Technetium Complex Containing A Tc=S Bond
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Copper Complexes as Anticancer Agents
No full textMetal-based antitumor drugs play a relevant role in antiblastic chemotherapy. Cisplatin is regarded as one of the most effective drugs, even if severe toxicities and drug resistance phenomena limit its clinical use. Therefore, in recent years there has been a rapid expansion in research and development of novel metal-based anticancer drugs to improve clinical effectiveness, to reduce general toxicity and to broaden the spectrum of activity. The variety of metal ion functions in biology has stimulated the development of new metallodrugs other than Pt drugs with the aim to obtain compounds acting via alternative mechanisms of action. Among non-Pt compounds, copper complexes are potentially attractive as anticancer agents. Actually, since many years a lot of researches have actively investigated copper compounds based on the assumption proposal that endogenous metals may be less toxic. It has been established that the properties of copper-coordinated compounds are largely determined by the nature of ligands and donor atoms bound to the metal ion. In this review, the most remarkable achievements in the design and development of copper(I, II) complexes as antitumor agents are discussed. Special emphasis has been focused on the identification of structure-activity relationships for the different classes of copper(I,II) complexes. This work was motivated by the observation that no comprehensive surveys of copper complexes as anticancer agents were available in the literature. Moreover, up to now, despite the enormous efforts in synthesizing different classes of copper complexes, very few data concerning the molecular basis of the mechanisms underlying their antitumor activity are available. This overview, collecting the most significant strategies adopted in the last ten years to design promising anticancer copper(I,II) compounds, would be a help to the researchers working in this field
Structural overview of technetium compounds (2000-2004)
No full textThis paper provides an overview of the about 80 crystal structures of technetium complexes described in the past 5 years and exhibiting some peculiar structural features. In almost 90% of the compounds, technetium shows an odd oxidation number, and by a large majority the revised complexes are mononuclear and neutral. The review especially focuses on nitrido-Tc(V), oxo-Tc(V) and fac-[Tc(CO)(3)](+) complexes, which cover approximately one-half of the X-ray structural reports
Mononuclear six-coordinated Ga(III) complexes: A comprehensive survey
No full textGiven the commercial availability of (68)Ge-(68)Ga generators, in principle analogous to the worldwide utilized (99)Mo-(99m)Tc generator, it is surprising that few (68)Ga agents have been developed beyond basic research toward clinical application. The use of the unconventional (68)Ga positron emitter would allow for a cost-effective production of (68)Ga radiotracers far from a cyclotron facility. Moreover, the use of (67)Ga radiopharmaceuticals for imaging studies, and the application of non-radioactive gallium compounds in the treatment of important disorders, including a number of cancer and infectious diseases, make studies on trivalent Ga coordination chemistry attractive for the design of novel gallium-based drugs. The aim of this review is to survey the reported crystal data of six-coordinated Ga(III) complexes in order to gain information to be used in the design of novel Ga complexes of medicinal interes
Structural overview of technetium compounds (1993-1999)
No full textThis paper investigates the structural aspects of technetium-containing complexes. The focus is on the description of the various coordination environments around the technetium center. The complexes are divided according to the coordination sphere and the most significant structural parameters are reviewed and discussed. The review covers the crystallographic determinations published in the years between 1993 and 1999. (C) 2001 Elsevier Science B.V. All rights reserved
Portable X-ray fluorescence device reveals the artistic palette of Carlo Bononi, Baroque artist from Ferrara
No full textThe principal aim of the in situ X-ray fluorescence (XRF) analysis on the canvas “The Coronation of the Virgin” was to characterise the colour palette of Carlo Bononi (Ferrara, 1580–1632), a lesser-known artist of the early Baroque period in Ferrara. More than 100 points were collected by means of an XRF spectrometer, but the presence of many overlapping painted layers left some doubts about the preparation and the background layers. The scanning electron microscopy with energy dispersive spectrometer analysis on two samples resolved some of these doubts. The results obtained indicate the use of typical 17th century pigments, such as lead white, vermilion, azurite and a copper-based green. For yellow pigments, the artist used the yellow ochre in some cases, while in others he used lead-tin yellow. We also individuated at least three different shades of umber. Almost all the pigments have been identified and they are the first step in establishing the technical apparatus necessary to understand the modus operandi of the Ferrarese artist
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
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