2,978 research outputs found
Oral Dysbiosis and Systemic Diseases: A Two-Way Relationship?
No full textThe human body consists of its own cells, but also of microorganisms that are found both inside and outside the human body [...
Recensione a Lorenzo Carletti e Cristiano Giacometti, Le due facce della croce. Giunta Pisano tra un profumiere ebreo e le leggi di Bottai, Pisa, Edizioni ETS, 2012
No full textLe vicende di un'opera di Giunta Pisano a Pisa durante la Seconda Guerra Mondial
Silica Gel Stabilized Na and Na/K Alloys: Highly Effective, Versatile and Environmentally Friendly Reducing Agents
No full textNa and Na/K alloys in the liquid phase can be absorbed into amorphous silica gel at loadings up to 40 wt%. Further heating of these so-called stage 0 materials at 150 or 400 °C furnishes stage I and stage II materials, respectively, as free-flowing powders that can be handled under much safer conditions than the corresponding starting materials. Stage I Na and Na2K possess valuable reducing properties and they have found a variety of low impact applications in organic synthesis, including, e.g., the reductive deprotection of several functional groups, the development of safer protocols to operate the Bouveault-Blanc and the Birch reductions, and a new and particularly efficient approach to the Grignard and Darzens reactions. 1 Introduction 2 Reductive Deprotection Procedures 3 Bouveault-Blanc Reduction of Esters 4 Ammonia-Free Birch Reductions 5 Synthesis of Alkyldiaryl- and Dialkylarylphosphines 6 C-C Bond Forming Reactions 7 Further Applications 8 Conclusion
Addressing Stereochemistry of Heterocyclic Compounds by DFT NMR Calculations
No full text[Figure not available: see fulltext.] This minireview aims to concisely present the state of the art from 2013 to 2017 in the joint application of a computational and experimental NMR approach to the stereostructural analysis of heterocyclic compounds. Despite being endowed with a limited number of degrees of freedom, heterocyclic compounds pose major conformational problems associated with the correct assessment of the ring puckering. Once the compound conformational preferences are defined, the main magnetic parameters (chemical shifts and coupling constants) can be predicted at various theoretical levels, with different computational costs, mainly depending on chosen number of conformers, method, functional, basis set, solvation model, and reference. To evaluate the performance of computational tools in determining relative configurations, beyond the classical statistical correlation parameters (R2, MAE, CMAE, ATE, RMSD), more sophisticated strategies were recently introduced, such as DP4, DP4+, and DP4 probability
A novel modified obturation technique using biosealers: An ex vivo study
No full textBackground: The root canal anatomy is a complex space, and using a single-cone obturation technique does not guarantee a complete filling. Aim: This research aimed to evaluate the actual temperature of the biosealer during the obturation phase inside the root canal using a new hot technique. In addition, this study evaluated the penetration depth of the biosealer inside dentinal tubules. Setting and Design: The current study was concluded on two ex vivo experiments; the former tested the temperature evaluation. The latter examined the penetration depth of the biosealer. Materials and Methods: In this study, 42 sec mandibular premolars were used, and two experiments were carried out. In the first experiment, two premolars were utilized, and two thermocouples of K-type for each tooth were used. During the second experiment, the penetration depth of the biosealer was examined, 40 teeth were selected. Root canals were prepared then divided into two obturation groups: A, gutta-percha, and biosealer with single-cone technique and B, gutta-percha, and biosealer with a newly proposed obturation method. Confocal laser scanning was used to assess the penetration of the sealer. Statistical Analysis Used: In the first experiment, the Bonferroni method was performed to compare the temperature data. The tests used in the second experiment were Shapiro-Wilk's test, Kruskal-Wallis, and Mann-Whitney tests. Results: The first experiment results showed that the heat does not reach the apical third using the new obturation method. In the second experiment, the results showed in Group B significantly higher biosealer penetration into the dentinal tubules as compared to Group A (P < 0.05). Conclusions: The highest level of penetration of the biosealer in the dentinal tubules was observed in the group of the new obturation method, and the last apical 3 mm remained at 37° using this novel hot modified technique providing no risk of chemical alteration of the biosealer
Il compito della Psicologia Sociale in un Corso di Laurea in Scienze della Comunicazione
No full textHubris research in business: taking stock and moving forward
No full textPurpose – There is growing interest in how hubris bias shapes managerial and entrepreneurial judgments
and decisions and, in turn, firm strategy and performance. Based on a 44-years dataset of articles reaching the
beginning of 2023, the authors offer a synthesis of hubris research published within business journals.
Design/methodology/approach – The authors implement a mixed-method approach offering a content
representation of 600 peer-reviewed articles extracted from Scopus. The authors conduct a bibliometric
investigation – employing Excel, VOSViewer and Biblioshiny software – and perform a qualitative review.
Findings – The analysis unveils four thematic clusters: hubris bias in financial policies (Cluster 1), hubris bias
in restructuring deals (Cluster 2), hubris bias in entrepreneurial contexts (Cluster 3) and hubris bias in strategic
decision-making (Cluster 4). Moreover, the authors infer that hubris research in business predominantly
developed from three disciplinary perspectives – finance, entrepreneurship and strategic management – and
progressed with limited interdisciplinary dialogue.
Practical implications – The authors call practitioners’ attention to the impact of the hubris bias in forming
financial, entrepreneurial and strategic choices. Managers get conscious of the risks of hubristic choices; hence,
they implement organizational practices that move forward with unbiased (or less biased) judgments and
decisions.
Originality/value – The authors offer an up-to-date and comprehensive view of hubris research in business.
Furthermore, the authors provide an integrative framework and a research agenda
UN’ALTERNATIVA “GREEN” AL TOLUENE
No full textIl ciclopentil metil etere, un solvente dal ridotto impatto ambientale (economicità atomica nella sintesi, bassa tossicità, ridotta formazione di perossidi, basso calore di vaporizzazione, elevata Teb, facilità di riciclo), è stato utilizzato con successo nella sintesi di acetali in condizioni di Dean-Stark
A Green Alternative to Toluene
Cyclopentyl methyl ether, a solvent endowed with low environmental impact properties (atom economic synthesis, low toxicity, high boiling point, resistant to peroxide formation, low heat of vaporization, narrow explosion range, highly hydrophobic, easy drying), was successfully employed in the synthesis of acetals under Dean-Stark reaction conditions
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