33,522 research outputs found
The survey of the dome of the basilica of St. Vitale in Ravenna
No full textLo studio presenta il risultato del rilievo 3d del sistema cupola, tiburio, tamburo della basilica di San Vitale a Ravenna
The archaeoacoustics of San Vitale, Ravenna
No full textThis research tests and assesses whether sixth-century social and cultural dynamics can be archaeologically identified by including the study of acoustics in the context of extant Late Antique Christian architecture, namely the centrally planned domed octagonal church of San Vitale at Ravenna. Implementing a holistic archaeological research strategy that includes human sensory perception of acoustical phenomena is the best approach to unravelling the complexities of social and cultural mechanisms operating in the sixth-century Mediterranean basin. The methods and issues of Archaeoacoustics are critiqued and developed in order to comment on the intentionality of acoustic attributes in sixth-century ecclesiastical architecture.The space syntax of San Vitale has been considered for isovists at key locations during the liturgical procession and sequence of the Mass celebration. These are compared with mapped areas of perceiving the acoustic characteristics of Clarity and Reverberation Time. Combining the visual and acoustic analysis of San Vitale, with a better understanding of its date and construction phases, the physical geometry and temporal logic of the church are discussed in relation to the reflexive exchange of influence between Ravenna, Milan and Constantinople. It is posited that liturgical and musical time and tempo is materially expressed in the evident and conceptual substance of San Vitale, a suggestion that offers a springboard for future study and debate
3-Aryl-2-isoxazolines and 3-arylisoxazoles from reaction of arylnitrile oxides and enolates: synthesis and reactivity
No full textIsoxazoles and isoxazolines are five-membered heterocycles widely used as versatile
building blocks in preparative organic chemistry, due to the easy cleavage of their N-O bond
[1]. They are masked forms of dicarbonyl compounds and are useful in the synthesis of other
heterocycles. Moreover, these heterocycles are components of a wide number of
pharmaceutical products and biologically active molecules [2], such as herbicides,
fungicides, analgesics, GABA-antagonists, anti-viral, antibacterial and anti-inflammatory
drugs [3].
The synthesis of functionalized 3-arylisoxazoles and 3-aryl-2-isoxazolines, from
reaction of arylnitrile oxides and enolates [4] will be reported in this presentation. The
regioselectivity and the synthetic versatility, due to the use of enolates intermediates, will be
discussed with particular attention to the methodologies useful for the preparation of
pharmacologically active heterocycles [5].
References
[1] (a) J. C. Badenock, "Topics in Heterocyclic Chemistry", Springer-Verlag Berlin Heidelberg, 2012, (G. W.
Gribble, ed.), vol 26, p. 261; (b) P. Grünanger, P. Vita-Finzi, J. E. Dowling, (eds.) Isoxazoles. Part 2, Vol. 170.
In: The Chemistry of Heterocyclic Compounds, John Wiley & Sons, 2009.
[2] (a) T. M. V. D. Pinho e Melo, Curr. Org. Chem. 2005, 9, 925; (b) P. Pevarello, R. Amici, M. G. Brasca, M.
Villa, M. Varasi Targets in Heterocyclic Systems 1999, 3, 301-339.
[3] J.J. Talley, D.L. Brown, J.S. Carter, M.J. Graneto, C.M. Koboldt, J.L. Masferrer, W.E. Perkins, R.S. Rogers,
A.F. Shaffer, Y.Y. Zhang, B.S. Zweifel, K. Seibert, J. Med. Chem. 2000, 43, 775.
[4] P. Vitale, A. Scilimati Curr. Org. Chem. 2013, 17, 1986-2000; (b) P. Vitale, A. Scilimati In: Advances in
Heterocyclic Chemistry, Eric F. V. Scriven and Christopher A. Ramsden (eds.) 2016, vol. 122, 1-41; (c) P.
Vitale, A. Scilimati, Synthesis (Germany) 2013, 45, 2940-2948.
[5] L. Di Nunno, P. Vitale, A. Scilimati, S. Tacconelli, and P. Patrignani, J. Med. Chem. 2004, 47, 4881; (b) P.
Vitale, S. Tacconelli, M. G. Perrone, P. Malerba, L. Simone, A. Scilimati, A. Lavecchia, M. Dovizio, E.
Marcantoni, A. Bruno, P. Patrignani J. Med. Chem. 2013, 56, 427
On incrementing interpretability of machine learning models from the foundations: a study on syllabic speech units
No full textAutomatic Detection of Parkinson's Disease with Connected Speech Acoustic Features: towards a Linguistically Interpretable Approach
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New fluorescence labeling isotactic polypropylenes as a tracer: a proof of concept
No full textPropylene-co-N-pentenyl-carbazole copolymers P(P-co-PK)s containing a low amount of isolated PK units were prepared by using the isospecific homogeneous Ziegler-Natta (Z-N) catalytic system rac-dimethylsilylbis(1-indenyl)zirconium dichloride/methylaluminoxane (MAO) with the aim to achieve fluorescent polypropylenes (PPs). Such materials could find applications both for the detection based on fluorescent tagging of PP-derived microplastic pollutants in organic tissues and as fluorescent markers of commercial i-PP allowing its identification during the separation phase of the plastic recycling process. P(P-co-PK)s are optically active and exhibit fluorescence emission when excited at 300 nm. They also show chemical and physical properties very close to those of commercial i-PPs. The P(P-co-PK) X-ray diffraction patterns match that of the i-PP α form, while P(P-co-PK) thermograms present endothermic peaks around 135 °C due to i-PP block melting. Microplastics from P(P-co-PK)s were prepared and tested as fluorescent markers to investigate the biological effect of plastics dispersed in an aquatic environment on leeches (Hirudo verbana). The first results indicate that P(P-co-PK)s are suitable to mimic PP-derived microplastic pollutants in animal tissues. Moreover, preliminary studies conducted on P(P-co-PK)/commercial i-PP blends show that P(P-co-PK)s can also be used as fluorescent dyes for i-PP identification during the separation step of the plastic recycling process
Tribological behaviour in a motor with turbocompressor utilizing the finite element method (FEM)
No full textSpectroscopic/Computational Characterization and the X-ray Structure of the Adduct of the VIVO-Picolinato Complex with RNase A
No full textThe structure, stability, and enzymatic activity of the adduct formed upon the reaction of the V-picolinato (pic) complex [VIVO(pic)2(H2O)], with an octahedral geometry and the water ligand in cis to the V=O group, with the bovine pancreatic ribonuclease (RNase A) were studied. While electrospray ionization-mass spectrometry, circular dichroism, and ultraviolet-visible absorption spectroscopy substantiate the interaction between the metal moiety and RNase A, electron paramagnetic resonance (EPR) allows us to determine that a carboxylate group, stemming from Asp or Glu residues, and imidazole nitrogen from His residues are involved in the V binding at acidic and physiological pH, respectively. Crystallographic data demonstrate that the VIVO(pic)2 moiety coordinates the side chain of Glu111 of RNase A, by substituting the equatorial water molecule at acidic pH. Computational methods confirm that Glu111 is the most affine residue and interacts favorably with the OC-6-23-Δenantiomer establishing an extended network of hydrogen bonds and van der Waals stabilizations. By increasing the pH around neutrality, with the deprotonation of histidine side chains, the binding of the V complex to His105 and His119 could occur, with that to His105 which should be preferred when compared to that to the catalytically important His119. The binding of the V compound affects the enzymatic activity of RNase A, but it does not alter its overall structure and stability
Comparison of different multivariate calibrations and ensemble methods for estimating selected soil properties with vis-NIR reflectance spectroscopy
No full textSustainable soil management requires a correct assessment of soil chemi- cal and physical properties. Historically, this has been gained through conventional laboratory analyses, which are considered costly and time-consuming, particularly when a large number of soil samples need to be analysed. An alternative, faster and less expensive, approach is based on the use of reflectance spectroscopy in the vis- NIR domain. This approach implies the calibration of predictive models that relate the spectral reflectance to soil properties. The goodness of the models can be partic- ularly influenced by the multivariate methods used. In this article, we compare the performance of different multivariate and statistical ensemble methods for estimating some basic soil properties, such as sand, silt, clay, and organic carbon in the specific pedo-environmental conditions of an important agricultural area in southern Italy
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