Search results for "LENI"

Splenic marginal zone lymphoma proposals for a revision of diagnostic, staging and therapeutic criteria

2007

Since the initial description of splenic marginal zone lymphoma (SMZL) in 1992, an increasing number of publications have dealt with multiple aspects of SMZL diagnosis, molecular pathogenesis and treatment. This process has identified multiple inconsistencies in the diagnostic criteria and lack of clear guidelines for the staging and treatment. The authors of this review have held several meetings and exchanged series of cases with the objective of agreeing on the main diagnostic, staging and therapeutic guidelines for patients with this condition. Specific working groups were created for diagnostic criteria, immunophenotype, staging and treatment. As results of this work, guidelines are pr…

FIRST APPLICATION OF MINIMAL RESIDUAL DISEASE ANALYSIS IN SPLENIC MARGINAL ZONE LYMPHOMA TRIALS: PRELIMINARY RESULTS FROM BRISMA/IELSG36 PHASE II STU…

2019

I ‘vasi di Centuripe’: per un approccio integrato

2017

Il contributo intende evidenziare le prospettive di un approccio interdisciplinare integrato allo studio della ceramica policroma “di Centuripe”. Dagli inizi del XX secolo, tale classe ha riscosso ampio apprezzamento per le sue delicate pitture e la ricchezza di ornamenti a rilievo applicati (dipinti e dorati) che abbelliscono i vasi, rendendoli pressoché inutilizzabili nella pratica per scopi funzionali, ma altamente efficaci come doni funerari in antico, e oggi come pezzi di grande impatto per commercianti di antichità e collezionisti moderni. Data la piaga, diffusa fino a tempi recenti, degli scavi clandestini, dei “restauri” arbitrari e delle falsificazioni, i vasi di Centuripe necessit…

The preparation of four- and six-membered chalcogenametallacyclic derivatives of group 4 metallocenes

1989

Abstract Four-membered metallacycles [(RC 5 H 4 ) 2 M(μ-E)] 2 (M = Zr, Hf; 1 , E = Se; 2 , E = S) were obtained by UV irradiation of dialkyl- or diaryl-metallocenes and equimolecular amounts of elemental chalcogen, but this method works only for bulky R groups. A more general route to compounds 1 and 2 involves the reaction of metallocene dichloride with chalcogenide anions. Six-membered metallacyclohexasulfanes (t-BuC 5 H 4 ) 2 MS 5 ( 3 , M = Zr, Hf) are obtained rather than compounds 2 when an excess of sulfur is used in the photolytic experiments, whereas compounds 1 were still formed when an excess of selenium was used. The observed difference is explained in terms of the solubility of …

The vegetation of a historic road system in the suburban area of Monte Pellegrino (Palermo, Sicily)

2020

Knowledge of the processes by which plants colonize old structures is a key element for nature-based design both in urban and suburban contexts. This paper analyses the natural vegetation on walls and in other microhabitats of the roadway structures of Monte Pellegrino (606 m a.s.l.) near Palermo (Sicily), built in the first half of the 1900s. The historical road has particular construction and architectural features, and its characteristics have been maintained to this day. The route, approximately 16 kilometers long, is well integrated within a site of high naturalistic value which has been designated as a Special Area of Conservation (ITA020014) of the Natura 2000 network, and it is also…

Thermal stability and reaction of chalcogen-containing metallocenic compounds with elemental chalcogens

1989

Abstract Dissymmetrical four-membered bimetallocenacycles (t-BuC 5 H 4 ) 2 M(μ-S) 2 M′-(RC 5 H 4 ) 2 (M, M′ = Zr, Hf; R = H, t-Bu) have been prepared and found to give redistribution products in solution at 190°C; identification of these products shows that the reaction involves exclusive cleavage of a metal-sulfur bond. Elemental sulfur and selenium react with chalcogen-containing complexes. The reaction is shown to involve the introduction of chalcogenic species in place of the σ-ligands of the complex to give either four-membered bimetallic complexes or catenated pentachalcogen metallocenic compounds. Some examples of insertion of sulfur and tellurium into the zirconium-methyl bond are a…

Metallocenes of Nb and Ta with η2-Se2H, SeH, and Se Ligands – Crystal Structures of [Cp′2Ta(SeH)H2] and [Cp′2Ta(=Se)H·W(CO)5] (Cp′ =tBuC5H4)

1999

The reactions of [Cp#2NbBH4] (1) [Cp# = C5Me5 (Cp*) or C5Me4Et] and [Cp′2TaH3] (Cp′ = tBuC5H4) with elemental selenium give complexes of the general composition [Cp2MSe2H]. These exist in three isomeric forms, A–C, depending on the metal and the chalcogen. [Cp#2NbSe2H] (2) incorporates the novel η2-Se2H ligand (C), which is labile when exposed to light. Solutions of 2(Cp*) can be converted into [Cp*2NbSe2H] (3), which exists in two isomeric forms A or B, along with [Cp*2NbSe3H] (4) and [Cp*2NbO2H] (5). [Cp′2Ta(η2-Se2)H] (6) is the only isomer found for the Ta system. Se abstraction by means of P(OEt)3 gives [Cp′2Ta(=Se)H] (7). Complex 7 can be reduced with Na/Hg and subsequently hydrolysed …

Experimental and Theoretical Investigations of Structural Trends for Selenium(IV) Imides and Oxides: X-ray Structure of Se3(NAd) 2

2004

The thermal decomposition of Se(NAd)(2) (Ad = 1-adamantyl) in THF was monitored by (77)Se NMR and shown to give the novel cyclic selenium imide Se(3)(NAd)(2) as one of the products. An X-ray structural determination showed that Se(3)(NAd)(2) is a puckered five-membered ring with d(Se-Se) = 2.404(1) A and |d(Se-N)| = 1.873(4) A. On the basis of (77)Se NMR data, other decomposition products include the six-membered ring Se(3)(NAd)(3), and the four-membered rings AdNSe(micro-NAd)(2)SeO and OSe(micro-NAd)(2)SeO. The energies for the cyclodimerization of E(NR)(2) and RNEO (E = S, Se; R = H, Me, (t)Bu, SiMe(3)), and the cycloaddition reactions of RNSeO with E(NR)(2), RNSO(2) with Se(NR)(2), and S…

"Sweet Chemistry": a Green Way for Obtaining Selenium Nanoparticles Active against Cancer Cells

2017

We present an environment friendly synthesis of selenium nanoparticles and the study of their cytotoxic activity against uterine sarcoma cancer and fibroblasts cells. Amorphous selenium (a-SeNPs) and trigonal selenium (t-SeNPs) were synthesized using D-fructose as the reducing agent and characterized by high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), powder X-ray diffraction analysis (XRD), inductively coupled plasma optical emission spectrometry (ICP OES), dynamic light scattering (DLS) to obtain zeta potential values and cyclic voltammetry (CV). Particularly, a-SeNPs presented high toxicity toward the resistant cancer cell line MES-SA/…

A Method to Quantitatively Trap Volatilized Organoselenides for Stable Selenium Isotope Analysis

2011

If volatile organoselenides are to be analyzed for their stable Se isotope composition to elucidate sources and formation processes, organoselenides need to be trapped quantitatively to avoid artificial Se isotope fractionation. We developed an efficient trap of organoselenides to be used in microcosms designed to determine the Se isotope fractionation by microbial transformation of inorganic Se to volatile organoselenides. The recoveries of volatilized dimethyldiselenide (DMDSe) from aqueous standard solutions by activated charcoal and alkaline peroxide solution with subsequent freeze-drying and purification via a cation exchange resin were tested. Microcosm experiments with the Se-methyla…