Supported Gold Nanoparticles for Alcohols Oxidation in Continuous-Flow Heterogeneous Systems

Gold nanoparticles (AuNPs) were anchored on alkynyl carbamate-functionalized support materials having the suitable features for application as catalysts in continuous-flow packed bed reactors. The functionalization step was carried out by grafting with the di-functional organosilane [3-(2-propynylcarbamate)propyl]triethoxysilane (PPTEOS) three commercial micrometer-sized oxide supports, i.e. silica, alumina, and titania. The alkynyl-carbamate moieties were capable to straightforwardly reduce the gold precursor HAuCl4 yielding the supported AuNPs systems Au/SiO2@Yne, Au/Al2O3@Yne, and Au/TiO2@Yne. A comparison among the three materials revealed that silica allowed the highest organic functionalization (12 wt%) as well as the highest gold loading (3.7 wt%). Moreover, TEM investigation showed only for Au/SiO2@Yne the presence of homogeneously distributed, spherically shaped AuNPs (av. diameter 15 nm). Au/SiO2@Yne is an efficient catalyst, both in batch and flow conditions, in the oxidation of a large variety of alcohols, using H2O2 as oxidizing agent, at a temperature of 90 \ub0C. Furthermore, under flow conditions, the catalyst worked for over 50 h without any significant decrease in the catalytic activity. The catalytic activity of the three catalysts was evaluated and compared in the oxidation of 1-phenylethanol as a model substrate. We found that the flow approach plays a strategic role in preserving the physical and chemical integrity of the solid catalysts during its use, with remarkable consequences for the reaction conversion (from 2% in batch to 80 % in flow) in the case of Au/TiO2@Yne

Development and characterization of a coloured sweet corn line as a new functional food

The standard sugary sweet corn (Zea mays saccharata Sturt.) is a maize variety grown for the fresh, frozen and canned markets, traditionally appreciated. Its kernels are characterized by the presence of some antioxidant substances suggested to be beneficial for cancer prevention. For this reason an interesting challenge for breeders is the development of sweet corn genotypes with naturally high antioxidant levels, starting from flavonoids. In fact important sources of antioxidants in maize are anthocyanins, considered as nutraceuticals because they have been proven to lower the risk of many chronic diseases. In this paper we report the development of a new coloured sugary line and the results of some analyses concerning flavonoid content before and after two different cooking treatments are discussed. Attention was mainly focused on the anthocyanins, the molecules suggested as being responsible for the nutraceutical properties of the new coloured sugary line. The results show that the presence of the anthocyanins also pushes up the flavonol and the phenolic acid amounts and gives the new coloured sugary line a higher scavenging power compared to the uncoloured control. The mild cooking seems not to significantly change the metabolites analyzed in the coloured kernels, while the stronger treatment seems to drastically decrease the amounts of pigments, without changing the structure of the leftover molecules. All these findings suggest that the new colored sugary line can be considered a new functional food, able to introduce healthy compounds into the diet of many people

Characteristics and patterns of care of endometrial cancer before and during COVID-19 pandemic

Objective: Coronavirus disease 2019 (COVID-19) outbreak has correlated with the disruption of screening activities and diagnostic assessments. Endometrial cancer (EC) is one of the most common gynecological malignancies and it is often detected at an early stage, because it frequently produces symptoms. Here, we aim to investigate the impact of COVID-19 outbreak on patterns of presentation and treatment of EC patients. Methods: This is a retrospective study involving 54 centers in Italy. We evaluated patterns of presentation and treatment of EC patients before (period 1: March 1, 2019 to February 29, 2020) and during (period 2: April 1, 2020 to March 31, 2021) the COVID-19 outbreak. Results: Medical records of 5,164 EC patients have been retrieved: 2,718 and 2,446 women treated in period 1 and period 2, respectively. Surgery was the mainstay of treatment in both periods (p=0.356). Nodal assessment was omitted in 689 (27.3%) and 484 (21.2%) patients treated in period 1 and 2, respectively (p<0.001). While, the prevalence of patients undergoing sentinel node mapping (with or without backup lymphadenectomy) has increased during the COVID-19 pandemic (46.7% in period 1 vs. 52.8% in period 2; p<0.001). Overall, 1,280 (50.4%) and 1,021 (44.7%) patients had no adjuvant therapy in period 1 and 2, respectively (p<0.001). Adjuvant therapy use has increased during COVID-19 pandemic (p<0.001). Conclusion: Our data suggest that the COVID-19 pandemic had a significant impact on the characteristics and patterns of care of EC patients. These findings highlight the need to implement healthcare services during the pandemic

Supported nanoparticles for catalysis and biomedical applications

In recent years we have prepared a large variety of stable supported metal nanoparticles by using supports such as silica, alumina, titania, magnetite (hereafter generally termed as Oxides Supports, OS), Indium Tin Oxide (ITO) and hydroxyapatite (HA) to be employed as catalytic systems and biomaterials. With regards to the OS, we have developed a convenient method for the anchoring of AuNPs on matrices modified with a propynylcarbamate functionality, without the need of any additional reducing and/or stabilizing agents. Among these systems, the Au/SiO2 catalyst was also the most active in the oxidation of a large variety of primary and secondary alcohols both in batch and flow settings (Fig. 1A), yielding very stable performances as a function of time without any detrimental activity degradation [1]. Figure 1. In the HA case we have reported an easy, green and low-cost method to support AgNPs onto multifunctionalized HA-R crystals (Fig. 1B, R = zoledronate, (9R)-9-hydroxystearate) obtaining materials that combine the biological properties of R with a significant long-standing antibacterial activity [2]. ___________ [1] M. Giorgetti, G. Aquilanti, B. Ballarin, M. Berrettoni, M.C. Cassani, S. Fazzini, D. Nanni, D. Tonelli, Anal. Chem. 2016, 88, 6873; M.C. Cassani, B. Ballarin, D. Barreca, E. Boanini, E. Bonansegna, G. Carraro, S. Fazzini, A. Mignani, D. Nanni, D. Pinelli, RSC Adv. 2016, 6, 25780; B. Ballarin, D. Barreca, E. Boanini, M.C. Cassani, P. Dambruoso, A. Massi, A. Mignani, D. Nanni, C. Parise, A. Zaghi, ACS Sustain. Chem. Eng. 2017, 5, 4746. [2] E. Boanini, P. Torricelli, C. Boga, G. Micheletti, M.C. Cassani, M. Fini, A. Bigi, Langmuir 2016, 32, 188; E. Boanini, P. Torricelli, F. Bonvicini, M.C. Cassani, M. Fini, G.A. Gentilomi, A. Bigi, Eur. J. Pharm. Biopharm. 2018, 127, 120; E. Boanini, M.C. Cassani, K. Rubini, C. Boga, A. Bigi, Nanomaterials 2018, 8, 390

RF-sputtering preparation of gold-nanoparticle-modified ITO electrodes for electrocatalytic applications

The preparation of gold-nanoparticle (AuNPs)-modified indium tin oxide (ITO) electrodes (AuNPs/ITO) was performed by radio-frequency (RF) sputtering from Ar plasmas at temperatures as low as 60\ub0C, tailoring the AuNP morphology and content as a function of the sole sputtering time. The latter parameter was varied from 5 to 20 min in order to investigate the influence of gold amount and distribution on the electrochemical performances of the resulting AuNPs/ITO systems. The electrodes were characterized using field emission-scanning electron microscopy (FE-SEM), UV\u2013vis absorption and x-ray photoelectron spectroscopies (XPS); moreover variable scan rate cyclic voltammetry (CV) studies were performed to examine their electrochemical behavior. The electrocatalytic activity of the nanostructured AuNPs/ITO electrodes toward methanol oxidation was investigated and compared with a continuous gold film (Aufilm/ITO). The catalytic efficiency of the AuNPs/ITO systems was found to increase with the gold content and the AuNPs\u2013support boundary region in the corresponding samples. For the longest sputtering time (i.e. 20 min) the performances of the nanostructured electrode were better than the Aufilm/ITO reference, despite the much lower catalyst amount. Furthermore, conversely from the AuNPs/ITO samples, in the Aufilm/ITO case the gold film displayed a poor adhesion to the substrate and the electrode could be used only for a limited number of electrochemical cycles

Supported gold nanoparticles catalysts for alkynes hydroamination.

Our research group has previously reported the preparation of gold nanoparticles (AuNPs) supported on different functionalized silica supports. We started using commercial polyethyleneimine-functionalized silica bead [1] and we continued preparing silica nanoparticles functionalized with alkynyl carbamate moieties. [2] Recently, we have focused on the straightforward synthesis of AuNPs anchored on commercial, micrometric oxide supports (i.e. SiO2, Al2O3, TiO2) previously modified with the di-functional organosilane [3-(2-propynylcarbamate)propyl]triethoxysilane (PPTEOS) by a grafting procedure. After being thoroughly characterized by several complementary techniques (XPS, TEM, SSNMR, AAS etc.), the catalytic activity of these systems (Au/OS@Yne) has been evaluated in the oxidation of alcohols both in batch and continuous-flow systems. [3] Furthermore, we have extended the same synthetic procedure to the preparation of a novel and magnetically recoverable catalyst, consisting of AuNPs supported on functionalized nano-magnetite (Au/Fe3O4@Yne). We now present the latest results obtained in the study of the catalytic application of Au/SiO2@Yne and Au/Fe3O4@Yne in the alkynes hydroamination reaction, which is considered the most atom efficient process for the formation of a series of nitrogen-containing compounds. Indeed, this transformation takes place without the formation of any side product and leads to the production of enamine, imine or substituted amines, which have a significant importance as bulk and fine chemicals or building blocks in organic synthesis. [1] S. Fazzini , D. Nanni , B. Ballarin , M. C. Cassani , M. Giorgetti , C. Maccato, A. Trapananti, G. Aquilanti and S. I. Ahmed, J. Phys. Chem. C. 2012, 116, 25434 1225443; M. Giorgetti, G. Aquilanti, B. Ballarin, M. Berrettoni, M. C. Cassani, S. Fazzini, D. Nanni and D. Tonelli, Anal. Chem. 2016, 88, 6873-6880; [2] S. Fazzini, M. C. Cassani, B. Ballarin, E. Boanini, J. S. Girardon, A.S. Mamede, A. Mignani and D. Nanni, J. Phys. Chem. C. 2014, 118, 24538-24547; M. C. Cassani, B. Ballarin, D. Barreca, E. Boanini, E. Bonansegna, G. Carraro, S. Fazzini, A. Mignani, D. Nanni, D. Pinelli, RSC Adv. 2016, 6, 25780-25788. [3] B. Ballarin, D. Barreca, E. Boanini, M. C. Cassani, P. Dambruoso, A. Massi, A. Mignani, D. Nanni, C. Parise, A. Zaghi, ACS Sus. Chem. Eng. 2017, 5, 4746-4756

Synthesis, characterization and study of the catalytic activity of supported gold nanoparticles for alkynes hydroamination

Our research group has previously reported the preparation of different silica supported gold nanoparticles (AuNPs) catalytically active in the reduction of nitrophenol to aminophenol. [1, 2] Recently, the focus of our research has shifted towards continuous flow nanocatalysis and for applications in packed bed reactors we have anchored AuNPs on commercial micrometer oxide supports (SiO2, Al2O3, TiO2), previously modified by grafting of the organosilane [3-(2-propynylcarbamate)propyl]triethoxysilane (PPTEOS). After thorough characterization, the catalytic activity of these systems has been evaluated in the oxidation of a large variety of primary and secondary alcohols, both under batch and continuous flow conditions. [3] We now present the results in the field of the hydroamination of alkynes catalysed by Au/SiO2@Yne and the new, magnetically recoverable Au/Fe3O4@Yne catalyst. [1] S. Fazzini , D. Nanni , B. Ballarin , M. C. Cassani , M. Giorgetti , C. Maccato, A. Trapananti, G. Aquilanti, and S. I. Ahmed, J. Phys. Chem. C. 116 (2012) 25434 1225443; M. Giorgetti, G. Aquilanti, B. Ballarin, M. Berrettoni, M. C. Cassani, S. Fazzini, D. Nanni, and D. Tonelli, Anal. Chem. 88 (2016) 6873-6880; [2] S. Fazzini, M. C. Cassani, B. Ballarin, E. Boanini, J. S. Girardon, A.S. Mamede, A. Mignani, and D. Nanni, J. Phys. Chem. C. 118 (2014) 24538-24547; M. C. Cassani, B. Ballarin, D. Barreca, E. Boanini, E. Bonansegna, G. Carraro, S. Fazzini, A. Mignani, D. Nanni, and D. Pinelli, RSC Adv. 6 (2016) 25780-25788. [3] B. Ballarin, D. Barreca, E. Boanini, M. C. Cassani, P. Dambruoso, A. Massi, A. Mignani, D. Nanni, C. Parise, and A. Zaghi, ACS Sus. Chem. Eng. 5 (2017) 4746-4756

Supported gold nanoparticles catalysts for alkynes hydroamination

Our research group has previously reported the preparation of gold nanoparticles (AuNPs) supported on different functionalized silica supports. We started using commercial polyethyleneimine-functionalized silica bead [1] and we continued preparing silica nanoparticles functionalized with alkynyl carbamate moieties. [2] Recently, we have focused on the straightforward synthesis of AuNPs anchored on commercial, micrometric oxide supports (i.e. SiO2, Al2O3, TiO2) previously modified with the di-functional organosilane [3-(2-propynylcarbamate)propyl]triethoxysilane (PPTEOS) by a grafting procedure. After being thoroughly characterized by several complementary techniques (XPS, TEM, SSNMR, AAS etc.), the catalytic activity of these systems (Au/OS@Yne) has been evaluated in the oxidation of alcohols both in batch and continuous-flow systems. [3] Furthermore, we have extended the same synthetic procedure to the preparation of a novel and magnetically recoverable catalyst, consisting of AuNPs supported on functionalized nano-magnetite (Au/Fe3O4@Yne). We now present the latest results obtained in the study of the catalytic application of Au/SiO2@Yne and Au/Fe3O4@Yne in the alkynes hydroamination reaction, which is considered the most atom efficient process for the formation of a series of nitrogen-containing compounds. Indeed, this transformation takes place without the formation of any side product and leads to the production of enamine, imine or substituted amines, which have a significant importance as bulk and fine chemicals or building blocks in organic synthesis. [1] S. Fazzini , D. Nanni , B. Ballarin , M. C. Cassani , M. Giorgetti , C. Maccato, A. Trapananti, G. Aquilanti and S. I. Ahmed, J. Phys. Chem. C. 2012, 116, 25434 1225443; M. Giorgetti, G. Aquilanti, B. Ballarin, M. Berrettoni, M. C. Cassani, S. Fazzini, D. Nanni and D. Tonelli, Anal. Chem. 2016, 88, 6873-6880; [2] S. Fazzini, M. C. Cassani, B. Ballarin, E. Boanini, J. S. Girardon, A.S. Mamede, A. Mignani and D. Nanni, J. Phys. Chem. C. 2014, 118, 24538-24547; M. C. Cassani, B. Ballarin, D. Barreca, E. Boanini, E. Bonansegna, G. Carraro, S. Fazzini, A. Mignani, D. Nanni, D. Pinelli, RSC Adv. 2016, 6, 25780-25788. [3] B. Ballarin, D. Barreca, E. Boanini, M. C. Cassani, P. Dambruoso, A. Massi, A. Mignani, D. Nanni, C. Parise, A. Zaghi, ACS Sus. Chem. Eng. 2017, 5, 4746-4756