55,610 research outputs found
Perrone M. S., Cardellini L.,
No full textEducation in our society is a complex process, and different stakeholders have high expectations towards the world of education. Teachers should be able to teach not only their subject but also to foster autonomous critical thinking, in order to enable students to play an active, and constructive role in the society. Teaching requires a lot of human and professional skills because among students we can have both those who have difficulties to learn, and gifted students. A university teaching method is presented that allows to achieve excellent results, both as student motivation, and as skill acquisition in problem solving. Students are required to solve both logic and chemical problems, easy and difficult, with the aim of not discourage anyone. The emphasis is placed on visible reasoning and students are asked to explain, illustrate, argue, and demonstrate the various steps in problem solving. Appropriate strategies that facilitate the acquisition of cognitive skills and problem solving are suggested. Particular attention is being given to help students with difficulties in the course. Many students are able to deliver original and creative solutions. They pass the exam with excellent grades even though the course requests are substantial
L-nucleosides
No full textThis chapter provides an overview concerning the synthesis of L-nucleosides and their analogues. The first section deals with L-nucleosides, which maintain a close relationship with ribose and deoxyribose derivatives. The second section covers furanose nucleosides without the 2′ and 3′ hydroxyl groups. The third section talks about carbovir, which has been reported as the first carbocyclic nucleoside analogue, with potent anti-HIV activity in vitro; its discovery provided a base for the synthesis of other carbocyclic analogues. Among all types of aza-nucleosides, five-membered pyrrolidine-type nucleosides have been investigated particularly because of their high similarity with naturally occurring nucleosides. Next, the chapter talks about the thionucleosides. Several purine and pyrimidine-L-dioxolane nucleosides have been reported using the acetoxy dioxolane 370 as a glycosyl donor for condensation under classical Vorbrüggen conditions. The final section talks about the oxathiolanyl nucleosides
"Opere di Origene"
No full textEdizione bilingue greco-latina, con traduzione italiana a fronte, introduzione e commento degli "Opera Omnia" di Origene. La collana, diretta da Manlio Simonetti (Professore emerito, Università di Roma "La Sapienza") e Lorenzo Perrone (Università di Bologna), è espressione del Gruppo italiano di ricerca su Origene e la tradizione alessandrina. Nel 2004 è stato pubblicato il seguente volume: "Commento a Matteo. Series/1", a cura di G. Bendinelli, R. Scognamiglio, M.I. Danieli, pp. 447
A Stereoselective Tyrosinase Model Compound Derived from an m-Xylyl-L-histidine Ligand
No full textThe aim of mimicking enzyme activity represents an important motivation for the development of new catalysts. A challenging objective is the development of chiral complexes for bioinspired enantioselective oxidation reactions. Herein, we report a new chiral dinuclear copper(II) complex based on a m-xylyl-bis(histidine) ligand (mXHI) as a biomimetic catalyst for tyrosinase and catechol oxidase. The new ligand improves a previous system also containing two tridentate N-3 units derived from l-histidine that were connected by a short, rigid ethanediamine bridge. In mXHI the bridge is provided by the more extended m-xylyl moiety. The dicopper(II) complex [Cu-2(mXHI)](4+) was studied as a catalyst for stereoselective oxidations of enantiomeric couples of chiral catechols of biological interest (L/D-dopa, L/D-dopa methyl ester, and (R/S)-norepinephrine), showing excellent discrimination capability, particularly for the methyl esters of dopa enantiomers. The catechol oxidation was studied in acetate buffer as slightly acidic medium, and a role of acetate as bridging ligand between the two coppers, preorganizing the dinuclear center in a more catalytic efficient structure, could be established. The oxidation of beta-naphthol and 3,5-ditertbutylphenol was studied as a model monophenolase reaction. The oxidation proceeds stoichiometrically, and the partial incorporation of O-18 into beta-naphthol when the reaction was performed using 18O2 suggests the existence of two competitive reaction pathways, a genuine monooxygenase mechanism and a radical pathway. However, the more challenging reaction on derivatives of l-/d-tyrosine did not lead to the desired monooxygenase product but only to products of radical oxidation. Complex [Cu-2(mXHI)](4+) was also used for the catalytic sulfoxidation of thioanisole in the presence of hydroxylamine as cosubstrate, in a preliminary attempt to model the reaction of external monooxygenases. The reaction proceeds with 25 turnovers, but the enantiomeric excess of sulfoxide was modest
«Simmetrie sarcastiche». Esili e migrazioni nella letteratura contemporanea di lingua tedesca degli scrittori di origine romena (C.D.Florescu e C.-F.Banciu)
No full textTravelling concepts in der interkulturellen Literatur (Franco Biondi, Gino Chiellino, Francesco Micieli)
No full textCorrection to: The decrease of non-complicated acute appendicitis and the negative appendectomy rate during pandemic (European Journal of Trauma and Emergency Surgery, (2021), 10.1007/s00068-021-01663-7)
No full textThe original version of this article unfortunately contained a mistake. The Acknowledgement with the members of the Appendicitis- COVID study group is missing. The correct version of is given below. Acknowledgements Members of the Appendicitis-COVID study group: Monza: Marco Nizzardo, Luca Nespoli, Luca Fattori, Luca Degrate, Stefano Perrone, Marco Cereda Bergamo: Michele Pisano, Elia Poiasina, Paolo Bertoli Lodi: Michele Ballabio, Stefano Braga Pavia: Giorgio Graziano Pisa: DarioTartaglia, Francesco Arces Lecco: Marco Mariani, Fulvio Tagliabue Parma: Gennaro Perrone, Alfredo Annicchiarico, Mario Giuffrida Legnano: Giovanni Ferrari, Antonio Benedetti, Niccolò Allievi Ponte San Pietro: Michele Ciocca, Enrico Pinotti, Mauro Montuori San Raffaele: Michele Carlucci, Valentina Tomajer Cesena: Paola Fugazzola The original article has been corrected
The Emerging Role of Metabolism in Brain-Heart Axis: New Challenge for the Therapy and Prevention of Alzheimer Disease. May Thioredoxin Interacting Protein (TXNIP) Play a Role?
No full textAlzheimer disease (AD) is the most frequent cause of dementia and up to now there is not an effective therapy to cure AD. In addition, AD onset occurs decades before the diagnosis, affecting the possibility to set up appropriate therapeutic strategies. For this reason, it is necessary to investigate the effects of risk factors, such as cardiovascular diseases, in promoting AD. AD shows not only brain dysfunction, but also alterations in peripheral tissues/organs. Indeed, it exists a reciprocal connection between brain and heart, where cardiovascular alterations participate to AD as well as AD seem to promote cardiovascular dysfunction. In addition, metabolic dysfunction promotes both cardiovascular diseases and AD. In this review, we summarize the pathways involved in the regulation of the brain-heart axis and the effect of metabolism on these pathways. We also present the studies showing the role of the gut microbiota on the brain-heart axis. Herein, we propose recent evidences of the function of Thioredoxin Interacting protein (TXNIP) in mediating the role of metabolism on the brain-heart axis. TXNIP is a key regulator of metabolism at both cellular and body level and it exerts also a pathological function in several cardiovascular diseases as well as in AD
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