1,720,983 research outputs found
Novel Silver Complexes as Additives for Innovative Composite Materials with Permanent Antimicrobial Activity
No full textIn summary, most of the experimental work of my PhD thesis has been devoted to develop novel silver complexes with suitable physico-chemical properties for their employment as additives in antimicrobial composite materials with persistent activity. Among the most relevant results, the silver coordination polymers seem to be the most effective for their application as additives, due to their high and broad spectrum antimicrobial activity. Such activity is persistent in time, likely because of a contact mechanism of toxicity against bacteria, due to exposed silver centers within the polynuclear chain, which are able to attract the negatively charged cell membranes of bacteria altering their membrane potential and provoking their death. In any case, the release of silver ions from the composite material seems very limited or absent, thanks to the insolubility of such silver coordination polymers in almost all solvents and water, an essential feature for their application as additives for plastics. Future developments of this research will be directed to optimize the homogeneity of the composites’ surfaces by changing the substituents in the HQR proligands with the aim of increasing their hydrophobicity and solubility in the polymeric matrices
Synthesis and Characterization of New Ruthenium(II) Arene Acylpyrazolone Complexes
No full textArene ruthenium(II) complexes have been widely studied in the recent years, and their chemistry has been extensively studied for arenes such as benzene and para-cymene. They have found applications in catalysis, supramolecular assemblies, molecular devices.1 Moreover, they have shown antiviral, antibiotic and anticancer activities.2 Recently, mononuclear Ru-acylpyrazolone complexes have been shown to exhibit interesting in vitro activity in some cancer cells.3 On the basis of the our previous work,4 we extend our investigation to the interaction of several acylpyrazolones ligands with (arene)ruthenium(II)dichloride acceptors and PTA (1,3,5-triaza-7-phosphaadamantane)(Figure 1). Their structures have been confirmed by analytical and spectral data. X-ray diffraction studies and their biological activity are under investigation
EUCHEME, EUropean CHemists for Energy, Materials and Environment. Intensive Programme (IP) Lifelong Learning Programme Erasmus
No full textThe main objective of the course is to provide a comprehensive and balanced overview of the most important aspects of different subjects (energy and materials production, fine chemicals, environment) related to organometallic chemistry, catalysis, advanced materials, green and environmental chemistry, bridging the gap between the need of advanced training and the actual offer in this fields
Complessi Acilpirazolonici di Argento(I) incorporati in Polietilene ad Alta Densita o in Cloruro di Polivinile con Potente Attivita' Antibatterica
No full textSono stati studiati complessi di Ag(I) che contengono leganti 4-acil-5-pirazolonici con differenti caratteristiche elettroniche e steriche, e diversi imidazoli L come leganti ancillari (L = imidazolo (imH); 1-metilimidazolo (Meim); 1-benzilimidazolo (Bzim); 2-etil-imidazolo (2EtimH); 1-benzil-2-metilimidazolo (2Mebzim); di(imidazol-1-il)metanone (COdim); 2,4,6-trimetilpiridina (Me3py); 2-trifluorometilbenzimidazolo (2tfbimH)). La sintesi, caratterizzazione, e struttura cristallina di questi composti è riportata nella seguente invenzione.
È stato trovato che questi composti additivati al polietilene alta densità (HDPE) o polivinilcloruro (PVC) esplicano una potente attività antimicrobica senza rilascio di ioni Ag+. In particolare, specifici test sono stati condotti su derivati additivati ai dischi di polietilene alta densità per verificarne la loro attività antimicrobica verso sospensioni di E. coli, P. aeruginosa e S. aureo
Silver(I) Acylpyrazolonate Complexes embedded in High Density Polyethylene or in polyvinyl chloride with Potent Antibacterial Activity
No full textComposite plastics, containing silver(I) acylpyrazolonate complexes embedded in high density polyethylene or polyvinyl chloride, display potent antibacterial activity by contact, without silver ions release
Bioactivity of Curcuminoids in Half-Sandwich Ru(II), Rh(III) and Ir(III) Complexes: benefits from cooking to medicine
No full textCurcumin has been used for centuries in Asia as a spice, natural colouring and traditional medicine owing to its anti-inflammatory, antioxidant and antitumoral effects [1]. An alternative strategy to improve the properties of curcumin, without the need to modify the drug, is its incorporation into metal complexes [2]. Ruthenium compounds have emerged in recent years as promising alternatives to
platinum drugs by displaying specific activities against different cancers, favorable toxicity and clearance properties [3]. Recently, also metal complexes based on Rhodium and Iridium have arisen as fascinating potential alternative metallodrugs [4]. In the present work we exploit the coordination chemistry of Ru(II) arene and pentamethylcyclopentadienyl Rh(III) and Ir(III) complexes with curcumin [5] and bisdemethoxycurcumin as co-ligands and full characterization of relative RAPTA type complexes with 1,3,5-triaza-7-phosphaadamantane ligand (PTA) [6]. Hydrolysis studies were carried out under pseudopharmacological conditions to evaluate their aqueous chemistry. The antiproliferative effects in two human ovarian cancer cell lines (A2780 and A2780cisR) and non-tumorigenic human embryonic kidney cells (HEK293) will be reported
Novel polyethylene-embedded silver(I) acylpirazolonate complexes with potent antibacterial activity.
No full textNovel polyethylene-embedded silver(I) acylpirazolonate complexes with potent antibacterial activity
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
Selective Anticancer Ruthenium(II) Arene RAPTA Type Complexes Containing Curcuminoids
No full textRuthenium-arene complxes are considered valid alternatives to platinum drugs, owing to their lower toxicity and stronger selectivity. Since curcumin possesses anti-inflamatory, antioxidant and antitumoral effects, it has been extensively studied as a chemo preventive agent in some cancer models. As continuation of our previous work, a series of novel Ru(II) arene RAPTA type derivatives (areme = cymene and hexamethylbenzene) containing corcumin-based ligands (curcH = curcumin, bdcurcH = bisdemethoxycurcumin) and PTA (1,3,5-triaza-7-phosphaadamantane) has been synthesized and fully characterized. The antitumor activity of the complexes has been evaluated in vitroagainst human ovarian carcinoma cells, A2780 and A2780cisR, as well as against non-tumorous Human Embryonic Kidney (HEK293) cells
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