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The genus zero contribution to the four-point correlator $\langle {\cal O}_{p_1}{\cal O}_{p_2}{\cal O}_{p_3}{\cal O}_{p_4}\rangle$ of half-BPS single-particle operators ${\cal O}_p$ in $\mathcal{N}=4$ super Yang-Mills at strong coupling computes the Virasoro-Shapiro amplitude of closed superstrings on $AdS_5\times S^5$. Combining Mellin space techniques, the large $p$ limit, and data about the spectrum of two-particle operators at tree level in supergravity, we design a bootstrap algorithm which heavily constrains its $\alpha'$ expansion. We use crossing symmetry, polynomiality in the Mellin variables and the large $p$ limit to stratify the Virasoro-Shapiro amplitude away from the ten-dimensional flat space limit. Then we analyse the spectrum of exchanged two-particle operators at fixed order in the $\alpha'$ expansion. We impose that the ten-dimensional spin of the spectrum visible at that order is bounded above in the same way as in the flat space amplitude. This constraint determines the Virasoro-Shapiro amplitude in $AdS_5\times S^5$ up to a small number of ambiguities at each order and we compute it explicitly for $(\alpha')^{5,6,7,8,9}$. As the order of $\alpha'$ grows, the ten dimensional spin grows, and the set of visible two-particle operators opens up. Operators illuminated for the first time receive a string correction to their anomalous dimensions. This correction is uniquely determined and lifts the residual degeneracy of tree level supergravity due to ten-dimensional conformal symmetry. We encode the lifting of the residual degeneracy in a characteristic polynomial. This object carries information about all orders in $\alpha'$.It is analytic in the quantum numbers, symmetric under an $AdS_5 \leftrightarrow S^5$ exchange, and it enjoys intriguing properties, which we explain and detail in various cases., Comment: 46 pages plus Appendices A and B; v2: 48 pages plus Appendices A and B, typos fixed, match with JHEP version; v3: added funding acknowledgement

We consider a set of half-BPS operators in $\mathcal{N}=4$ super Yang-Mills theory which are appropriate for describing single-particle states of superstring theory on AdS${}_5 \times S^5$. These single-particle operators are defined to have vanishing two-point functions with all multi-trace operators and therefore correspond to admixtures of single- and multi-traces. We find explicit formulae for all single-particle operators and for their two-point function normalisation. We show that single-particle $U(N)$ operators belong to the $SU(N)$ subspace, thus for length greater than one they are simply the $SU(N)$ single-particle operators. Then, we point out that at large $N$, as the length of the operator increases, the single-particle operator naturally interpolates between the single-trace and the $S^3$ giant graviton. At finite $N$, the multi-particle basis, obtained by taking products of the single-particle operators, gives a new basis for all half-BPS states, and this new basis naturally cuts off when the length of any of the single-particle operators exceeds the number of colours. From the two-point function orthogonality we prove a multipoint orthogonality theorem which implies vanishing of all near-extremal correlators. We then compute all maximally and next-to-maximally extremal free correlators, and we discuss features of the correlators when the extremality is lowered. Finally, we describe a half-BPS projection of the operator product expansion on the multi-particle basis which provides an alternative construction of four- and higher-point functions in the free theory., 46 pages, appendices A,B,C,D and many illustrations

We have developed a novel method for crystalline hydrogenation of graphene on the nanoscale. Molecular hydrogen was physisorbed at 5 K onto pristine graphene islands grown on Cu(111) in ultrahigh vacuum. Field emission local to the tip of a scanning tunneling microscope dissociates H 2 and results in hydrogenated graphene. At lower coverage, isolated point defects are found on the graphene and are attributed to chemisorbed H on top and bottom surfaces. Repeated H 2 exposure and field emission yielded patches and then complete coverage of a crystalline √3 × √3 R30° phase, as well as less densely packed 3 × 3 and 4 × 4 structures. The hydrogenation can be reversed by imaging with higher bias voltage.

The restoration of mandibular bone defects with non-vascularized bone grafts depends on the diagnosis, anatomical site, extent of the defect, and the patient's age, as well as the surgeon's experience. The aim of this study was to perform a systematic literature review on mandibular reconstruction for segmental mandibular bone defects using non-vascularized bone grafts to answer the following question: Is there scientific evidence to support the use of this technique? The initial literature search in PubMed, Scopus, and Cochrane databases identified 862 articles. Of these, 25 were included in the final review. These articles encompassed 926 procedures with non-vascularized bone grafts; 76.1% were from the iliac crest. Benign tumours were the major cause of these defects (56.8%), and 44.7% of defects were located in the lateral mandibular area. Although this technique showed a high occurrence of complications (290 in 873 patients, some with more than one complication), these did not account for treatment failure. The restoration of bone defects due to malignant tumours treated with radiation therapy had lower success rates, and these appear to be a contraindication for the technique. Although standardized randomized controlled clinical studies are needed to obtain better clinical evidence for treatment choices in general, the use of non-vascularized bone grafts for mandibular reconstruction showed an 87.6% success rate in this review.

We characterized CO2 adsorption and diffusion on the missing row reconstructed (2√2 × √2) R45° O-Cu(100) surface using a combination of scanning tunneling microscopy (STM) and density functional theory (DFT) calculations with dispersion. We deposited CO2 molecules in situ at 5 K, which allowed us to unambiguously identify individual CO2 molecules and their adsorption sites. Based on a comparison of experimental and DFT-generated STM images, we find that the CO2 molecules sit in between the O atoms in the missing row reconstructed O-Cu(100) surface. The CO2 molecules are easily perturbed by the STM tip under typical imaging conditions, suggesting that the molecules are weakly bound to the surface. The calculated adsorption energy, vibrational modes, and diffusion barriers of the CO2 molecules also indicate weak adsorption, in qualitative agreement with the experiments. A comparison of tunneling spectroscopy and DFT-calculated density of states shows that the primary change near the Fermi level is associated with changes to the surface states with negligible contribution from the CO2 molecular states.

We present a study of graphene/substrate interactions on UHV-grown graphene islands with minimal surface contamination using \emph{in situ} low-temperature scanning tunneling microscopy (STM). We compare the physical and electronic structure of the sample surface with atomic spatial resolution on graphene islands versus regions of bare Cu(111) substrate. We find that the Rydberg-like series of image potential states is shifted toward lower energy over the graphene islands relative to Cu(111), indicating a decrease in the local work function, and the resonances have a much smaller linewidth, indicating reduced coupling to the bulk. In addition, we show the dispersion of the occupied Cu(111) Shockley surface state is influenced by the graphene layer, and both the band edge and effective mass are shifted relative to bare Cu(111)., 12 pages, 3 figures

We present a scanning tunneling microscopy (STM) study of native defects in graphene islands grown by ultra-high vacuum (UHV) decomposition of ethylene on Cu(111). We characterize these defects through a survey of their apparent heights, atomic-resolution imaging, and detailed tunneling spectroscopy. Bright defects that occur only in graphene regions are identified as C site point defects in the graphene lattice and are most likely single C vacancies. Dark defect types are observed in both graphene and Cu regions, and are likely point defects in the Cu surface. We also present data showing the importance of bias and tip termination to the appearance of the defects in STM images and the ability to achieve atomic resolution. Finally, we present tunneling spectroscopy measurements probing the influence of point defects on the local electronic landscape of graphene islands., Comment: 16 pages, 5 figures

A new method of analysis is described for estimating the deformations and strains caused by shallow undrained penetration of piles and caissons in clay. The formulation combines previous analyses for steady, deep penetration, with methods used to compute soil deformations due to near-surface ground loss, and is referred to as the Shallow Strain Path Method (SSPM). Complete analytical solutions for the velocity and strain rates are given for a planar wall, an axisymmetric, closed-ended pile and unplugged, open-ended pile geometries. In these examples, the analyses consider a single source penetrating through the soil at a constant rate, generating a family of penetrometers with rounded tips, referred to as simple wall, pile and tube geometries. Soil deformations and strains are obtained by integrating the velocity and strain rates along the particle paths. The transition from shallow to deep penetration is analysed in detail. Shallow penetration causes heave at the ground surface, while settlements occur only in a thin veneer of material adjacent to the shaft and in a bulb-shaped region around the tip. The size of this region increases with the embedment depth. Deformations inside an open-ended pile/caisson are affected significantly by details of the simple tube wall geometry. © 1997 by John Wiley & Sons, Ltd.

Oral carcinoma is a form of neoplasia with well-known clinical and morphologic features. This study presents the difference of incidence and behaviour in relation to the time of onset of oral carcinoma, and describes the experience made at the Department of Oral and Maxillofacial Surgery of the Second University of Naples.In this study 118 patients are analysed. They are divided into 3 groups according to age: group A up to 40 years; group B, from 41 to 75 years; group C from 75 years onwards.No patient of group A showed a carcinoma of verrucous type. This histologic type was found in group B, (14 patients: 14,1%) and in group C (6 patients: 46,1%).The results of this study underline the importance of the time of onset in the behaviour of oral carcinoma and the age of patients.

Gli autori presentano dei casi clinici di grande rialzo di seno mascellare con innesti misti di osso autologo, omologo e alloplastico. A distanza di 6 mesi sono state praticate delle biopsie ossee nei futuri siti implantari e sono stati valutati i comportamenti biologici e istologici di tali materiali di riempimento. A seguito di una frattura su impianto dopo 3 anni dal suo posizionamento, vi é stata l'opportunità di poter eseguire, durante l'installazione di una nuova fixture, una ulteriore biopsia ossea. Da tali esami istologici si deduce che in un primo momento i fenomeni infiammatori prevalgono sulla osteogenesi; a tre anni, tutto il materiale innestato é trasformato in osso neoformato con assenza completa di infiammazione.

To examine to what extent physicians follow a regional guidelines for the diagnosis, staging, treatment and follow-up of patients with squamous cell carcinoma of the lower and upper lip.retrospective analysis of data from the medical records of 42 patients diagnosed with squamous cell carcinoma of the lower and upper lip during the period 1990-2000.Department of head and neck pathology, oral cavity and audio-verbal communication of Naples University.the data were collected by this Department.In accordance with the TNM system, the 50% of cases was in stage T1, 33% in T2, 14% in T3. In few cases (3%) the lesion was in stage T4. All cases were in M0 and only 8% of cases presented nodal disease at diagnosis (N1). The type of treatment in relation to age was in agreement with the guidelines in 34% of cases. Of the 42 surgically-treated patients, only 4 showed, after 12 months, a local recurrence.Prognosis is good if squamous carcinoma is diagnosed early.

Lo scopo del presente lavoro é stato quello di presentare una rara complicanza conseguente all'estrazione del terzo molare incluso. Essa non é un evento frequente, anzi tra, le complicanze secondarie a questo pipo di chirurgia é tra le più rare e la sua incidenza in letteratura é compresa tra lo 0,2 e lo 0,4 %

The authors carry out a review of the international literature on an alternative methodology to surgical therapy of lithiasis of the salivary glands, indicating information, limitations and possible complications. More than fifty papers by international authors were analysed regarding their experience on the use of electro-magnetic waves in the treatment of salivary gland lithiasis. It was observed that extracorporeal lithotripsy is an alternative and valid method to surgery, considering that the complications are negligible. Considering the expectations and the relationship between cost and advantage, extracorporeal lithotripsy can be considered as first treatment with surgery as second therapeutic choice.

A case of angioleiomyoma localized at the level of the soft palate is reported. The 31-year-old patient presented a non-pathognomonic clinical picture and the anamnestic finding of the relatively slow growth of the neoformation raised problems of differential diagnosis in relation to benign growth and lesion of a non-neoplastic nature. The differential diagnosis was only obtained with histological examination of biopsy material.

A rare case of primary malignant melanoma of the oral cavity is reported and a literature review of etiopathogenesis, biological bases and prognosis is made. The hypotheses to explain the very severe prognosis of malignant melanoma of the oral cavity with respect to that of skin are discussed. The therapeutic approaches are described as well as the frequent difficulty to perform them in relation to the anatomical region and the wide extension of the tumoral lesion.

Individual Zn acceptors in the GaAs (110) surface layer are studied with a scanning tunneling microscope. Tunneling spectroscopy reveals a peak associated with a Zn acceptor state, whose linewidth and response to local band bending depend on proximity to neighboring subsurface Zn acceptors. Though identical in topographic images, surface-layer Zn with nearby subsurface neighbors exhibits a broad peak that is insensitive to band bending, while more isolated surface-layer Zn exhibit a narrow peak which is sensitive to band bending. These results are suggestive of a shallow-to-deep acceptor transition, driven by the random dopant distribution.

Interfacial bonding geometry and electronic structures of In(2)O on InAs and In(0.53)Ga(0.47)As(001)-(4×2) have been investigated by scanning tunneling microscopy/scanning tunneling spectroscopy (STM/STS). STM images show that the In(2)O forms an ordered monolayer on both InAs and InGaAs surfaces. In(2)O deposition on the InAs(001)-(4×2) surface does not displace any surface atoms during both room temperature deposition and postdeposition annealing. Oxygen atoms from In(2)O molecules bond with trough In/Ga atoms on the surface to form a new layer of O-In/Ga bonds, which restore many of the strained trough In/Ga atoms into more bulklike tetrahedral sp(3) bonding environments. STS reveals that for both p-type and n-type clean In(0.53)Ga(0.47)As(001)-(4×2) surfaces, the Fermi level resides near the valence band maximum (VBM); however, after In(2)O deposition and postdeposition annealings, the Fermi level position is close to the VBM for p-type samples and close to the conduction band minimum for n-type samples. This result indicates that In(2)O bonding eliminates surface states within the bandgap and forms an unpinned interface when bonding with In(0.53)Ga(0.47)As/InP(001)-(4×2). Density function theory is used to confirm the experimental finding.

Il saggio ricostruisce la storia della tradizione manoscritta e a stampa delle rime di Angelo Di Costanzo, analizzando un nuovo testimone, allo stato conservato in una biblioteca privata di Palma de Mallorca, latore di cinquanta componimenti inediti, le cui caratteristiche specifiche ne denunciano la natura di raccolta strutturata dall'autore fatta ricopiare da un copista di professione all'evidente scopo di farne omaggio a una personalità di alto rango. Sulla base del nuovo testimone è possibile riaprire il discorso sull'edizione critica delle rime di Di Costanzo, stampate per l'ultima volta in forma incompleta nel 1843.

Si segue in senso diacronico la posizione di Benedetto Croce intorno al Seicento, e si ipotizza che, dopo una qualche simpatia dei primi anni del Novecento, la risoluta condanna di questo periodo, avvenuta negli anni Venti, sia in parte spiegabile con le affinità che il critico coglieva tra le ostentazioni e gli eccessi del Barocco e quelli del periodo fascista durante il quale scrisse la «Storia dell'età barocca in Italia».

In questo contributo si indagano alcuni aspetti delle varianti filologiche e del dialogo fra immagine e parola nelle "Symbolicae quaestiones" di Achille Bocchi

Il capitolo, parte di un manuale scolastico i cui curatori si sono proposti di far convergere le ragioni della storia letteraria e quelle dell'antologia, è al tempo stesso un profilo della vita e delle opere di Giovanni Verga e un commento approfondito ad alcuni brani tratti da "Vita dei campi" ("Rosso Malpelo"), "Novelle rusticane" ("La roba"), "I Malavoglia" (dai capp. II, IV, IX, XI, XVI), "Mastro-don Gesualdo" (parte IV cap. V).

Il capitolo, parte di un manuale scolastico i cui curatori si sono proposti di far convergere le ragioni della storia letteraria e quelle dell'antologia, è al tempo stesso un profilo della vita e delle opere di Niccolò Machiavelli e un commento approfondito ad alcuni brani tratti dall'epistolario (lettera a F. Vettori del 10 dicembre 1513), dal "Principe" (dai capp. I, VI, VII, XV, XVII, XVIII, XXV, XXVI) e dalla "Mandragola" (atto II scena 6 e atto V scena 4).

Il capitolo, parte di un manuale scolastico i cui curatori si sono proposti di far convergere le ragioni della storia letteraria e quelle dell'antologia, è al tempo stesso un profilo della vita e delle opere di Alessandro Manzoni e un commento approfondito a "La Pentecoste" e "Il Cinque Maggio", nonché ad alcuni brani tratti dall'"Adelchi" (atto III, coro; atto IV, coro), dalla "Lettre à M. Chauvet", dalla Lettera "Sul Romanticismo" a Cesare d'Azeglio e dai "Promessi sposi" (dai cap. I, III, VI, VIII, IX, XIII, XXI, XXXIII, XXXV, XXXVIII).

Il capitolo, parte di un manuale scolastico i cui curatori si sono proposti di far convergere le ragioni della storia letteraria e quelle dell'antologia, è al tempo stesso un profilo della vita e delle opere di Torquato Tasso e un commento approfondito ad alcuni brani tratti dalla "Gerusalemme liberata" (I 1-5; II 14-37; III 17-20; XII 51-69; XVI 9-22, XVIII 12-16), dalle "Rime" (nn. 23 e 43) e dall'"Aminta" (atto I, coro).

Presentazione di un dipinto su tavola di scuola di Francesco del Cossa, attestante l'importazione a Bologna dei modelli elaborati dall'artista a Ferrara.

La poetica del romanzo storico in Bacchelli e la sua narrativa storica, con particolar riferimento ai volumi del "Mulino del Po"