421 research outputs found
Determinazione gascromatografica degli acidi grassi liberi nelle acque di vegetazione degli oleifici
No full textE’ stato sviluppato un metodo per la determinazione gascromatografica (GC) degli acidi grassi
liberi nelle acque di vegetazione degli oleifici (AV). Il campione in esame è stato acidificato a pH
2-3 per far precipitare le proteine. La frazione colloidale è stata eliminata per aggiunta di acetone e
le interferenze dovute ai composti fenolici per aggiunta di polinivinilpirrolidone. Il campione è stato
chiarificato per centrifugazione e un’aliquota è stata successivamente iniettata nel sistema GC. Sia
gli acidi grassi a catena C2-C8, derivanti dal metabolismo microbiologico, che gli acidi grassi a
catena C16-C18, provenienti dall’olio originariamente presente nelle olive, sono stati quantificati in
una sola analisi utilizzando l’acido nonanoico come standard interno. In generale sono state trovate
quantità piuttosto elevate di acido acetico, nell’intervallo da 1.000 a 4.000 mg/L di AV.
Abstract.
A method was developed for the gas chromatographic (GC) determination of free fatty acids (FFA)
in olive mill waste waters (OMW). The sample under examination was acidified to pH 2-3 to cause
protein precipitation. Elimination of the colloidal fraction was obtained by addition of acetone.
Polyvynilpirrolidone was added to eliminate the interference by phenolic compounds. The sample
was then clarified by centrifugation and an aliquot was injected into the GC system. Both the C2-C8
FFA, coming from microbial metabolism, and the C16-C18 FFA, coming from the oil originally
present in the olives, were quantified in a single run by employing nonanoic acid as the internal
standard. Rather high amounts in particular of acetic acid were generally found, usually in the range
from 1,000 to 4,000 mg/L of OMW
La Fine del Potere Ottomano. L’ultimo sultano, l’ultimo califfo, gli ultimi gran visir
No full textContrariamente alla fine dell’Impero zarista, dell’Impero asburgico e di quello germanico, la fine dell’Impero ottomano sopravvenne dopo lunga e tortuosa agonia, prodotta principalmente dalle confliggenti ambizioni delle potenze che avevano vinto la Grande Guerra. A cento anni dall’abolizione del califfato (3 marzo 1924), Fabio L. Grassi ripercorre la storia ben poco conosciuta degli uomini che ressero e rappresentarono l’impero in quegli anni. L’autore ne illustra la vita, la carriera, le propensioni politiche, l’opera, le posizioni di volta in volta assunte, la loro sorte successiva, oltre che la loro dimensione culturale, morale e psicologica. Ciò che fecero e non fecero l’ultimo sultano, l’ultimo califfo e gli ultimi gran visir, ovvero i massimi rappresentanti della «Turchia legale», nelle loro relazioni da una parte con gli Alleati dall’altra con la «Turchia ribelle», costituisce un insieme complesso, ambiguo e in parte ancora misterioso.Contrary to the end of the Tsarist Empire, of the Habsburg Empire and of the Germanic, Empire, the end of the Ottoman Empire came after a long and torturous agony, caused mainly by the conflicting ambitions of the powers that had won the Great War. One hundred years after the abolition of the caliphate (3 March 1924), Fabio L. Grassi traces the scarcely story
known of the men who ruled and represented the empire in those years. The author illustrates their life, career and political propensities policies, their acts, the positions taken from time to time, theirs subsequent fate, as well as their cultural, psychological and moral dimension. What the last sultan, the last caliph and the last grand viziers, i.e. the highest representatives of «legal Türkiye», did and did not do, in their relations on the one hand with the AlliedPowers on the other with "rebel Türkiye", constitutes a
complex, ambiguous and partly still mysterious whole
Improving drug efficacy and specificity by innovative drug delivery approaches
No full textThe limited efficacy of current therapeutic approaches for a number of socially relevant human diseases requires the exploration of alternative and more effective therapeutic strategies. In this regard, the researchers have pursued on one hand the identification of novel and more effective therapeutic molecules and on the other the optimization of drug delivery systems.
So far, many therapeutic molecules, especially those used as anticancer drugs, are plagued by a low therapeutic index being the efficacious dose very close to the lethal one; moreover, they often lack any specificity of action. This aspect can be improved by the use of drug delivery systems composed of different drug carriers including lipids and polymers. The carriers, often in the shape of nanoparticles , can be loaded by the therapeutic molecule and directed against the target cells via the presence of targeting moieties allocated on the nanoparticle surface.
The specificity of the complex carrier/drug can be further improved by the use of therapeutic molecules preferentially/exclusively active on the target diseased cells. Molecules active against diseased-associated target (oncogenes etc) may hit the diseased cells leaving healthy cells substantially unaffected. In this regard, in the last three decades, nucleic acid based drugs (NABDs) have emerged as an attractive and novel alternative with great therapeutic potential. NABDs, which include antisense oligonucleotides, decoys, aptamers, triple helix forming oligonucleotides, DNAzymes, Ribozymes and small interfering RNAs, have been shown to be able to efficiently and specifically counteract pathological gene expression in many different experimental systems. Notably as they can be engineered to hit virtually any cell target, their potential applicability is very broad.
Despite NABD broad potential applicability, their use in the clinic is limited by the lack of optimal delivery systems. Due to their hydrophilic nature, NABDs cannot efficiently cross cellular membrane for which appropriate carriers are needed. Moreover, their instability in serum requires a proper protection to prevent a fast degradation which would invariably lead to the abrogation of any significant therapeutic effect.
The present special issue will be focused on the critical description of some aspects related to the optimization of drug delivery with a particular emphasis on NABD; despite this, a discussion about the possibility to use/adapt NABD developed delivery systems for more conventional drugs, is also present.
The papers of Chan et al., of Marrache et al, of Schaffert et al., Jung et al. and Grassi et al. describe different delivery approaches for NABD and other commonly used therapeutic molecules for several pathological conditions. In the paper of Chan et al. attention is given to liposome and polymeric based delivery systems with regard to DNA enzymes; the described studies offer perspectives on future methodologies for improved DNAzyme delivery and utility as novel drugs. Marrache et al. describe the use of nanoparticles (made by polymer, liposome and other delivery agents), as delivery devices which can be engineered to load multiple drugs with varied physicochemical properties, contrast agents, and cellular or intracellular component targeting moieties. Schaffert et al draw their attention on the description of delivery systems based on the polycation linear polyethylenimine, where peptide based ligands are attached to the polycation via heterobifunctional polyethylene glycol linker molecules. Conjugate synthesis, in vitro testing and in vivo cancer models in rodents are discussed. Jung et al describe the employment of the thermo sensitive pluronic-based core/shell nanoparticles, formed using various strategies such as self-assembly and temperature induced-phase transition. Particular emphasis is given to the use of the nanoparticles for tumor targeting, stimulated release of proteins, and cancer imaging capabilities. Grassi et al, beside discussing the above mentioned delivery systems, for most of the different types of NABDs, draw their attention on the complex situation of NABD delivery to the arteries describing the advantages and dis-advantages of three different administration routes i.e. systemic, perivascular and intravascular.
The papers of Lico et al, Pagliari et al and Castronovo et al report the use of “living delivery systems” and describe the influences of nano-systems on NABD. Lico et al. focus their attention on the use of a different approach for NABD delivery based on plant viruses which have a size particularly suitable for nanoscale applications and can offer several advantages being structurally uniform, robust, biodegradable and easy to produce. Pagliari et al. continue the description of “living vector” reporting the possible and very innovative use of stem cells as delivery devices for therapeutic molecules to the injured myocardium. Finally, in the paper of Castronovo et al., a completely innovative point of view about NABD complexation in nano-carriers is provided. The author show that the functionality of NABD in nano-systems is highly dependent upon the local density, molecular flexibility and network of weak interactions between adjacent molecules. The understanding of these properties can enable the development of powerful molecular tools for nano-medicine.
In conclusion, whereas the developmental process of many delivery systems is still at the beginning, other delivery strategies are closer to possible applications. Regardless of the fact that the delivery systems are used for NABD or clinically available drugs, we believe the target tissue will mainly determine the nature of the optimal strategy. Despite the delivery issue can and should be further optimized, the encouraging results displayed so far in different experimental models using NABD or clinically used drugs, fully justify further economic and scientific efforts
I linguaggi del metareale nella cultura catalana
No full textLinguaggi del metareale nella cultura catalan
I linguaggi del metareale nella cultura catalana
No full textLinguaggi del metareale nella cultura catalan
Thermoremendable Styrenic Polymers by Controlled Radical Copolymerization of Styrene with bioderived 2-vinylfuran
No full textThermoremendable Styrenic Polymers by Controlled Radical Copolymerization of Styrene with bioderived 2-vinylfuran
A. Grassi,* A. Buonerba, C. Capacchione, S. Milione
Department of Chemistry and Biology “Adolfo Zambelli”, University of Salerno – Italy
CIRCC - Interuniversity Consortium on Chemical Reactivity and Catalysis
*Corresponding author: [email protected]
Keywords: Biosourced olefins, functional olefin copolymer, furan-maleimide Diels Alder reaction.
Abstract
2-vinylfuran (2VF) is a bioderived olefin synthesized by Peterson methylenation of furfural, a cheap platform molecule resulting from acid catalyzed hydrolysis and dehydration of pentosanes from lignocellulosic biomass. Ideal ATR copolymerization of styrene with 2VF yielded random copolymers (S-co-2VFs) in a wide range of composition and high monomer conversion.[1] The S-co-2VFs are stable for years in solution and solid state at room temperature; radical oxidation of the furan moieties starts in air at temperature higher than 120°C whereas thermal degradation occurs at 380°C. Diels Alder (DA) cycloaddition reaction of S-co-2VFs with bismaleimide (BMI) produces thermorevesible crosslinks: the thermodynamic and kinetic parameters of this reaction were investigated by NMR and FT-IR spectroscopy to assess the optimal condition for high crosslink degree and self healing conditions. The mechanical properties of the S-co-2VFs, before and after reaction with BMI, were compared using INSTRON analysis and nanoidentation of polymeric thin films by Atomic Force Microscopy.[2] Moreover simple thermal treatment of mechanically fractured films of S-co-2VFs reacted with BMI allowed full repairing in 80 min (Figure 1).
Scheme. Diels Alder reaction of S-co-2VFs with BMI.
Figure 1. Fractured (a) and healed (b) polymer film of S-co-2VF crosslinked with BMI after thermal annealing at 150°C.
References
[1] S. Ortega Sáncheza, F. Marra, A. Dibenedetto, M. Aresta, A. GrassiMacromolecules 2014, 47, 7129−7137.
[2] A. Grassi, A. Buonerba, C. Capacchione, S. Milione ACS National Meeting San Diego (USA) 2016
Large N dualities and transitions in geometry
No full textThis chapter is based on lectures given by the first author in May 2001 in Como. The second author attended the lectures and volunteered to help write the notes; in the end MR completely wrote sections 9.2.2, 9.2.3 and the appendices, which were only sketched in the lectures
Author Correction: Coronavirus disease 2019 (COVID-19) in Italy: features on chest computed tomography using a structured report system (Scientific Reports, (2020), 10, 1, (17236), 10.1038/s41598-020-73788-5)
No full textThe original version of this Article contained errors in the spelling of the authors Roberto Grassi, Roberta Fusco, Maria Paola Belfiore, Alessandro Montanelli, Gianluigi Patelli, Fabrizio Urraro, Antonella Petrillo, Vincenza Granata, Palmino Sacco, Maria Antonietta Mazzei, Beatrice Feragalli, Alfonso Reginelli & Salvatore Cappabianca which were incorrectly given as Grassi Roberto, Fusco Roberta, Belfiore Maria Paola, Montanelli Alessandro, Patelli Gianluigi, Urraro Fabrizio, Petrillo Antonella, Granata Vincenza, Sacco Palmino, Mazzei Maria Antonietta, Feragalli Beatrice, Reginelli Alfonso & Cappabianca Salvatore. These errors have now been corrected in the PDF and HTML versions of the Article
La maturità di Alessandro Fei del Barbiere, in bilico tra Maniera e Riforma
No full textThis article studies the mature career of the Florentine painter Alessandro Fei del Barbiere (1537-1592), beginning with the rediscovery of the 'Ascension' altarpiece formerly in the Albizi Chapel in the destroyed church of San Pier Maggiore, Florence. Studying this painting and others recorded in 1584 by the biographer Raffaello Borghini, such as the two altarpieces for Santa Maria delle Grazie and the Madonna dell'Umiltà in Pistoia, the author reconstructs a body of works showing how in the 1580s Fei gradually went beyond the archaic style of his apprenticeship - he had been trained by Ridolfo del Ghirlandaio and Pierfrancesco Foschi, but was also marked by the Maniera of Vasari - evolving towards naturalism in both mimesis and pictorial handling. In Florence, his development partly parallels that of Santi di Tito and his circle, but Fei was also influenced by a probable sojourn during the early part of that decade in Rome, where he could have been inspired by Girolamo Muziano and the painters working for Pope Gregory XIII. Among other proposals, the author suggests that the artist was responsible for decorating the chancel of Fiesole Cathedral (c. 1584-1589), which consisted of an altarpiece, only rarely discussed by scholars, and a cycle of frescoes hitherto attributed to Nicodemo Ferrucci
Selective and Efficient Reduction of Nitrobenzene to Aniline catalyzed by AuNPs Embedded in a Nanoporous Crystalline Polymeric Support
No full textCongresso Divisione Chimica Industriale
Salerno, Settembre 2015
Selective and Efficient Reduction of Nitrobenzene to Aniline catalyzed
by AuNPs Embedded in a Nanoporous Crystalline Polymeric Support
Annarita Noschese1*, Antonio Buonerba1, Carmine Capacchione1, Stefano Milione1, Alfonso Grassi1
1 - Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II - 84084 Fisciano (SA), Italy, and CIRCC-Bari, Italy
Abstract
Supported Gold Nanoparticles (AuNPs) efficiently catalyze both oxidation and reduction reactions. E.g. aerobic oxidation of alcohols and cross coupling reactions of alcohols leading to esters, amide, imine have been widely and successfully explored [1]. On the other side the reduction of nitroarenes to anilines using NaBH4, H2, silanes, formic acid, CO/H2O is a benchmark reaction for testing their catalytic performances in reduction reactions [2].
During reaserch efforts many supports have been exploited (carbon based supports, polymers, inorganic oxides) but their role is still under discussion. A semicrystalline porous polymeric support, consisting of syndiotactic polystyrene-co-cis-1,4-polybutadiene [3] has been successfully tested in our group and the AuNPS embedded in this polymer matrix (AuNPs-sPSB) were investigated in the reduction of nitrobenzene to aniline. The polymorphic behaviour of the host polymer matrix has been studied to optimize the catalyst performances. The nanoporous crystalline forms of the sPSB matrix, namely and , allowed a total conversion of nitrobenzene in 40 min at room temperature, with 100% selectivity in aniline. On the contrary the not permeable crystalline form gave a less reactive and selective catalyst; actually azobenzene and azoxybenzene were detected as intermediates compounds providing information on the cascade of the reduction reactions and the global reaction mechanism. Among the catalysts to date reported in the literature, the AuNPs-sPSB catalyst showed the highest activity (TOF=6000 h-1). The catalyst is very stable under the reaction conditions and reusable for at least three times without loss of catalytic activity.
Keywords: Gold Nanoparticles, Polymeric Matrix, Reduction.
* Corresponding author: [email protected]
References
[1] A. Corma, H. Garcia, Chem. Soc. Rev. 37 (2008) 2096
[2] S. Fountoulaki, V. Daikopoulou, P. L. Gkizis, I. Tamiolakis, G.S. Armatas, I. N. Lykakis, ACS Catal. 4 (2014) 3504; X. Liu, S. Ye, H.-Q. Li, Y.-M. Liu, Y. Cao, K.-N. Fan, Catal. Sci. Technol. 3 (2013) 3200; L. He, L.-C. Wang, H. Sun, J. Ni, Y. Cao, H.-Y. He, K.-N. Fan, Angew. Chem. Int. Ed. 48 (2009) 9538.
[3] A. Buonerba, C. Cuomo, S. Ortega Sánchez, P. Canton, A. Grassi, Chem. Eur. J. 18 (2012) 709; A. Buonerba, A. Noschese, A. Grassi, Chem. Eur. J. 20 (2014) 5478
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