72 research outputs found
Orge e orgiasmo rituale nel mondo antico. Alcune note
This paper deals with the issue of the etymology and semantic developments of the word orgia in Greek and Roman language and ritual practice, with particular reference to Dionysiac religion. Relying on the definition of orgy currently accepted in the study of religion (transgressive collective behaviour meant to sanction a festive period and to reinforce the vital energies of cosmos and human groups by indulging to rave music, frantic dances and promiscuous sexual intercourses) it describes orgiastic practices occurring in various ancient Mediterranean mystery cults, with reference to reversal rituals and to similar accounts reported by Christian haeresiologists for Gnostic conventicles
Coping with Ancient Gods, Celebrating Christian Emperors, Proclaiming Roman Eternity : Rhetoric and Religion in Late Antique Latin Panegyrics
The present contribution provides an examination of the relationship between the emperor and the divine sphere in Latin panegyric poetry of the fifth and sixth centuries. Following the path magisterially set forth by Claudian, poets like Sidonius Apollinaris and, later on, Corippus employs the same literary genre to praise the newly-come Germanic kings or the Eastern Emperor. They have, however, to face a profoundly transformed historical and political realm, not to mention a different approach towards religion. Whereas Panegyrici Latini and Claudian could make wide use of mythological similes to celebrate Rome, her grandeur and the deeds of the emperor, his successors deal with the ancient gods in quite a clear-cut or, so to say, crystallized way. They show a conservative (and, to some extent, nostalgic) attitude and still believe in the endurance of Rome, which is fated to last eternally. The sacralization of Rome (with the concurring ideas of a Christian providence and the literary cliché of pagan aeternitas) is integrated within the frame of an empire that has become totally Christianized and, especially in the East, finds in political theology a privileged terrain to establish its roots. In particular the link between Christianity and the emperor as vicar of God is well outlined by the symbolism of court ceremonial and gesture, which panegyrics describe in great detail
Giant ambipolar Rashba effect in a semiconductor: BiTeI
We observe a giant spin-orbit splitting in bulk and surface states of the
non-centrosymmetric semiconductor BiTeI. We show that the Fermi level can be
placed in the valence or in the conduction band by controlling the surface
termination. In both cases it intersects spin-polarized bands, in the
corresponding surface depletion and accumulation layers. The momentum splitting
of these bands is not affected by adsorbate-induced changes in the surface
potential. These findings demonstrate that two properties crucial for enabling
semiconductor-based spin electronics -- a large, robust spin splitting and
ambipolar conduction -- are present in this material.Comment: 4 pages, 3 figure
The momentum and photon energy dependence of the circular dichroic photoemission in the bulk Rashba semiconductors BiTeX (X = I, Br, Cl)
Bulk Rashba systems BiTeX (X = I, Br, Cl) are emerging as important
candidates for developing spintronics devices, because of the coexistence of
spin-split bulk and surface states, along with the ambipolar character of the
surface charge carriers. The need of studying the spin texture of strongly
spin-orbit coupled materials has recently promoted circular dichroic Angular
Resolved Photoelectron Spectroscopy (cd-ARPES) as an indirect tool to measure
the spin and the angular degrees of freedom. Here we report a detailed photon
energy dependent study of the cd-ARPES spectra in BiTeX (X = I, Br and Cl). Our
work reveals a large variation of the magnitude and sign of the dichroism.
Interestingly, we find that the dichroic signal modulates differently for the
three compounds and for the different spin-split states. These findings show a
momentum and photon energy dependence for the cd-ARPES signals in the bulk
Rashba semiconductor BiTeX (X = I, Br, Cl). Finally, the outcome of our
experiment indicates the important relation between the modulation of the
dichroism and the phase differences between the wave-functions involved in the
photoemission process. This phase difference can be due to initial or final
state effects. In the former case the phase difference results in possible
interference effects among the photo-electrons emitted from different atomic
layers and characterized by entangled spin-orbital polarized bands. In the
latter case the phase difference results from the relative phases of the
expansion of the final state in different outgoing partial waves.Comment: 6 pages, 4 figure
Radial Spin Texture of the Weyl Fermions in Chiral Tellurium
Trigonal tellurium, a small-gap semiconductor with pronounced magneto-electric and magneto-optical responses, is among the simplest realizations of a chiral crystal. We have studied by spin- and angle-resolved photoelectron spectroscopy its unconventional electronic structure and unique spin texture. We identify Kramers–Weyl, composite, and accordionlike Weyl fermions, so far only predicted by theory, and show that the spin polarization is parallel to the wave vector along the lines in k space connecting high-symmetry points. Our results clarify the symmetries that enforce such spin texture in a chiral crystal, thus bringing new insight in the formation of a spin vectorial field more complex than the previously proposed hedgehog configuration. Our findings thus pave the way to a classification scheme for these exotic spin textures and their search in chiral crystals
Bulk and surface band structure of the new family of semiconductors BiTeX (X=I, Br, Cl)
We present an overview of the new family of semiconductors BiTeX (X = I, Br, Cl) from the perspective of angle resolved photoemission spectroscopy. The strong band bending occurring at the surface potentially endows them with a large flexibility, as they are capable of hosting both hole and electron conduction, and can be modified by inclusion or adsorption of foreign atoms. In addition, their trigonal crystal structure lacks a center of symmetry and allows for both bulk and surface spin-split bands at the Fermi level. We elucidate analogies and differences among the three materials, also in the light of recent theoretical and experimental work
CONTROLLO DEL DOLORE OSSEO CON CLODRONATO, BIFOSFONATO INIETTABILE
Dagli inizi degli anni ’90 sono stati introdotti nella clinica numerosi farmaci attivi sul tessuto osseo. I bisfosfonati, analoghi dei fosfonati, sono composti in grado di controllare la formazione e la dissoluzione del calcio fosfato in vitro così come la mineralizzazione ed il riassorbimento osseo in vivo. Questi composti, vengono attualmente utilizzati nel trattamento di varie patologie ossee: osteolisi con ipercalcemia indotta da neoplasie, morbo di Paget, osteoporosi, sindrome neuro-algo-distrofica, osteolisi periprotesica e, in associazione ad altre terapie, nelle metastasi ossee con marcata osteolisi come in caso di mieloma multiplo e di carcinoma mammario. Il clodronato, analogo sintetico del pirosfosfato, appartiene a questa categoria di farmaci. Il clodronato svolge un’azione inibitoria sull’attività osteoclastica, impedendo il riassorbimento osseo mediato dagli osteoclasti, e un’attività antinfiammatoria inibendo la liberazione di citochine da parte dei macrofagi. Questo meccanismo di azione spiega il provato effetto antalgico che si riscontra clinicamente dopo la sua somministrazione e la sua più specifica indicazione d’impiego in alcune patologie a patogenesi infiammatoria. Il farmaco sembra inoltre possedere un’azione analgesica pura attraverso un altro meccanismo d’azione anti-nocicettivo come valutato da studi sperimentali nei ratti e nei top
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