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36 results on '"Meo, Paolo Lo"'

1. An automatic L1-based regularization method for the analysis of FFC dispersion profiles with quadrupolar peaks

Author

Landi, Germana, Spinelli, Giovanni V., Zama, Fabiana, Martino, Delia Chillura, Conte, Pellegrino, Meo, Paolo Lo, and Bortolotti, Villiam

Subjects
Mathematics - Numerical Analysis, 65F22, 65K10, G.1.0, G.1.6, G.4
Abstract

Fast Field-Cycling Nuclear Magnetic Resonance relaxometry is a non-destructive technique to investigate molecular dynamics and structure of systems having a wide range of applications such as environment, biology, and food. Besides a considerable amount of literature about modeling and application of such technique in specific areas, an algorithmic approach to the related parameter identification problem is still lacking. We believe that a robust algorithmic approach will allow a unified treatment of different samples in several application areas. In this paper, we model the parameters identification problem as a constrained $L_1$-regularized non-linear least squares problem. Following the approach proposed in [Analytical Chemistry 2021 93 (24)], the non-linear least squares term imposes data consistency by decomposing the acquired relaxation profiles into relaxation contributions associated with 1H-1H and 1H-14N dipole-dipole interactions. The data fitting and the L1-based regularization terms are balanced by the so-called regularization parameter. For the parameters identification, we propose an algorithm that computes, at each iteration, both the regularization parameter and the model parameters. In particular, the regularization parameter value is updated according to a Balancing Principle and the model parameters values are obtained by solving the corresponding $L_1$-regularized non-linear least squares problem by means of the non-linear Gauss-Seidel method. We analyse the convergence properties of the proposed algorithm and run extensive testing on synthetic and real data. A Matlab software, implementing the presented algorithm, is available upon request to the authors.

Published
2022

11. Host-guest interactions between beta-cyclodextrin and the (Z)-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole: the first kinetic study of a ring-ring interconversion in a 'confined environment'

Author

Guernelli, Susanna, Lagana, Maria Francesca, Spinelli, Domenico, Meo, Paolo Lo, Noto, Renato, and Riela, Serena

Subjects
Chemistry, Organic -- Research, Cyclodextrins -- Physiological aspects, Ring formation (Chemistry) -- Physiological aspects, Heterocyclic compounds -- Physiological aspects, Biological sciences, Chemistry
Abstract

Research has been conducted on the beta-cyclodextrin. The role of this compound in the (Z)-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole's mononuclear heterocyclic rearrangement has been investigated and the results are reported.

Published
2002

32. A quantitative study of substituent effects on oxidative cyclization of some 2arylsubstituted aldehyde thiosemicarbazones induced by ferric chloride and cupric perchlorate

Author

Noto, Renato, Meo, Paolo Lo, Gruttadauria, Michelangelo, and Werber, Giuseppe

Abstract

As a development of our previous work, we performed a kinetic study of the oxidative cyclization reaction of some 2,4diarylsubstituted aldehyde thiosemicarbazones 1aninduced by ferric chloride and by cupric perchlorate. The results of cyclization of 1anwere compared to those of the corresponding 2methyl derivatives. The kinetic data were analyzed by means of the Hammetts equation.

Published
1999
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34. 1,2,3-Oligotriazoles modified halloysite nanotubes as potential active biological species: synthesis and characterization

Author

Marina Massaro, Carmelo Giuseppe Colletti, Giuseppe Cavallaro, Giuseppe Lazzara, Paolo Lo Meo, Serena Riela, Renato Noto, Massaro, Marina, Colletti, Carmelo Giuseppe, Cavallaro, Giuseppe, Lazzara, Giuseppe, Meo, Paolo Lo, Riela, Serena, and Noto, Renato

Subjects
Halloysite nanotubes, 1,2,3-oligotriazole, covalent modification, Organic Chemistry, Huisgen reaction, Settore CHIM/06 - Chimica Organica, HNTs-prodrug, Settore CHIM/02 - Chimica Fisica
Abstract

In the last years, the development of nano-formulations for cancer treatment represents one of the major challenges of the scientific research. The prodrug strategy, that combines chemotherapeutic agents with nanocarriers such as halloysite nanotubes (HNTs), is a promising strategy both to improve the biological activity of the drug molecules and to reduce the side effects of drugs. Herein we report the synthesis and characterization of a HNTs prodrug based on 1,2,3-triazole units covalently linked to HNTs external surface, bearing different positively charged moieties, which could present interesting pharmacological activities.

Published
2022
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35. Evaluation of adsorption ability of Cyclodextrin-Calixarene Nanosponges towards Pb2+ ion in aqueous solution

Author

Paolo Lo Meo, Demetrio Milea, Alberto Pettignano, Antonella Di Vincenzo, Salvatore Cataldo, Pellegrino Conte, Cataldo, Salvatore, Meo, Paolo Lo, Conte, Pellegrino, Vincenzo, Antonella Di, Milea, Demetrio, and Pettignano, Alberto

Subjects
Nanosponges, Polymers and Plastics, Environmental remediation, Speciation, Inorganic chemistry, Remediation, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Ion, Metal, Adsorption, Calixarene, Materials Chemistry, Settore CHIM/01 - Chimica Analitica, chemistry.chemical_classification, Aqueous solution, Cyclodextrin, Organic Chemistry, Settore CHIM/06 - Chimica Organica, 021001 nanoscience & nanotechnology, FFC-NMR relaxometry, Lead, 0104 chemical sciences, Anodic stripping voltammetry, chemistry, visual_art, visual_art.visual_art_medium, 0210 nano-technology
Abstract

Different cyclodextrin-calixarene nanosponges (CyCaNSs) have been characterized by means of FFC-NMR relaxometry, and used as sorbents to remove Pb2+ ions from aqueous solutions. Considering that the removal treatments may involve polluted waters with different characteristics, the adsorption experiments were performed on solutions without and with the addition of background salts, under different operational conditions. The adsorption abilities and affinities of the nanosponges towards Pb2+ ions were investigated by measuring the metal ion concentration by means of Inductively Coupled Plasma Emission Spectroscopy (ICP-OES) and Differential Pulse Anodic Stripping Voltammetry (DP-ASV). The acid-base properties of nanosponges and of metal ion as well as their interactions with the other interacting components of the systems have been considered in the evaluation of adsorption mechanism. Recycling and reuse experiments on the most efficient adsorbents were also performed. On the grounds of the results obtained, post-modified CyCaNSs appear promising materials for designing environmental remediation devices.

Published
2021

36. Diastereoselective synthesis of 2-phenylselenenyl-1,3-anti-diols and 2-phenylselenenyl-1,3-anti-azido-alcohols via hydroxy and azido-selenenylation reactions.

Author

Riela S, Aprile C, Gruttadauria M, Meo PL, and Noto R

Subjects
Hydroxylation, Models, Biological, Propanols chemistry, Selenic Acid, Stereoisomerism, Substrate Specificity, Alcohols chemical synthesis, Alcohols chemistry, Organoselenium Compounds chemical synthesis, Organoselenium Compounds chemistry, Selenium Compounds chemistry
Abstract

A method to synthesize 2-phenylselenenyl-1,3-anti-diols and 2-phenyl- selenenyl-1,3-anti-azidoalcohols via hydroxy- or azido-selenenylation of trans-allylic alcohols is reported. Moreover, the first example of hydroxyl-selenenylation of an allylic azide is presented. Yields ranging from moderate to good and diastereomeric ratios up to 95:5 are achieved.

Published
2005
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