569 research outputs found

    Network recovery from massive failures under uncertain knowledge of damages

    Get PDF
    This paper addresses progressive network recovery under uncertain knowledge of damages. We formulate the problem as a mixed integer linear programming (MILP), and show that it is NP-Hard. We propose an iterative stochastic recovery algorithm (ISR) to recover the network in a progressive manner to satisfy the critical services. At each optimization step, we make a decision to repair a part of the network and gather more information iteratively, until critical services are completely restored. Three different algorithms are used to find a feasible set and determine which node to repair, namely, 1) an iterative shortest path algorithm (ISR-SRT), 2) an approximate branch and bound (ISR-BB) and 3) an iterative multi-commodity LP relaxation (ISR-MULT). Further, we have modified the state-of-the-Art iterative split and prune (ISP) algorithm to incorporate the uncertain failures. Our results show that ISR-BB and ISR- MULT outperform the state-of-the-Art 'progressive ISP' algorithm while we can configure our choice of trade-off between the execution time, number of repairs (cost) and the demand loss. We show that our recovery algorithm, on average, can reduce the total number of repairs by a factor of about 3 with respect to ISP, while satisfying all critical deman

    Oral amelanotic melanoma: a case report

    Get PDF
    Objectives. Primary oral melanoma is a very rare malignancy, representing about 0.5% of all melanomas, characterized by a wide clinical-histological variability and a very aggressive behavior. Aim of the present study is to describe a case of oral amelanotic melanoma, an infrequent variant with a poorer prognosis than that of pigmented melanomas for a more aggressive biological behavior and frequent delays for the correct diagnosis and for starting the treatment. Case report. A 53-year-old white man referred at the Department Surgical, Oncological and Oral Sciences for a macular, scarsely pigmented lesion with irregular margins, located on anterior region of hard palate. The lesion, completely asymptomatic and without any history of trauma or injury, was observed by his dentist some months ago. The patient was a smoker (about 20 cigarettes a day for 30 years) and his anamnesis was negative for any systemic diseases and drug assumption. Histological examination, following the incisional biopsy, showed the hyperplasia of the junctional melanocytes with occasionally dendritic appearance and light atypia; on the recommendation of pathologist, a second incisional biopsy was performed, and a definitive diagnosis of “amelanotic melanoma in situ” was confirmed. After diagnosis, the patient was referred to the unit of Head and Neck Surgery for staging and surgical approach of the lesion. Conclusions. This case report underlines the importance to perform biopsy of all lesions of the oral cavity to rule out malignancy, even when slightly colored, asymptomatic and with a clinically harmless presentation. Besides benign diseases (e.g melanotic macules, nevi, extravasation of blood pigments, amalgam tattoos and deposition of other exogenous/endogenous pigments), rare variant of non-pigmented melanoma should be considered in order to avoid a dangerous diagnostic and therapeutic delay

    Oral squamous cell carcinoma as a complication of chronic graft-versus-host disease: a case report

    Get PDF
    Objectives. Chronic Graft-Versus-Host Disease (cGVHD) is an immunoregulatory disorder which occurs after allogeneic hematopoietic-cell transplantation (HCT) and often shares features of autoimmunity and immunodeficiency. GVHD related oral manifestations include severe oral pain, xerostemia, ulcerative lesions, and mucositis. Furthermore,a major late suggested complication of HSCT is the dramatically increased risk of secondary malignancies including oral cancer and oral cGVHD-releted inflammation may be considered a potential risk factor. Case report. A 51-year-old male patient referred in 1994 to our surgery for cGVHD oral lesions secondary to HCT for acute myelogenous leukemia developed in 1992. In 2010, an incisional biopsy in left retrocommissural region for an erosive lesion was performed and microscopic analysis revealed an intense lymphoplasmacytic inflammatory infiltrate. In 2011, clinical intraoral examination revealed white verrucous plaque lesion associated with ulcerations on the gingiva of the V sextant and on the lower labial mucosa; two incisional biopsies of oral mucosa and an incisional skin biopsy were performed. Microscopic analysis revealed a well differentiated SCC, a moderately differentiated SCC and a skin high grade dysplasia. Patient was surgically treated and is currently in follow up. Conclusions. Several authors suggest that cGVHD-related inflammation could be an important risk factor for carcinogenesis, also for oral cavity. Then it is recommended close follow-up to all patients treated with HCT, particularly when they develop graft-versus-host disease, and any suspicious oral lesions should be biopsied to rule out dysplasia or malignancy

    DIC analysis of mechanical response of tooth aligners under simulated swallowing acts

    Get PDF
    In this work, the mechanical and deformation behavior of clear Polyethylene Terephthalate-glycol (PET-g) aligners, under cyclic loading was investigated using a full-field optical technique: the Digital Image Correlation. In particular, the PET-g aligners thermoformed from 0.88 mm thick discs, were subjected to cyclic compression tests for 13000 load cycles from 0 to 50 N in the atmospheric environment (~25°C). This number of cycles was chosen because it simulates, on average, the intraoral load associated with the swallowing acts that an aligner is subjected to during the time of use of 1 week. At the same time, the results from the analysis of hysteresis loops obtained by the DIC technique were compared with those obtained by the testing machine. The mechanical response of clear aligners was evaluated in terms of maximum displacement, energy loss and relative stiffness along the load direction to seven different stages of the 13000 load cycles. A comparable trend was found between the measurements obtained by Digital Image Correlation analysis and the analysis of the hysteresis loops obtained from the cyclic compression tests. Furthermore, the morphological features of the PET-g aligner at the end of the tests were analyzed by optical microscopy (OM). The OM analyses showed that thesurface of PET-g aligner was affected by morphological variations such as high depressions and cracks

    Sella turcica and craniofacial morphology in patients with palatally displaced canines: a retrospective study

    Get PDF
    Background: The aim of the study was to evaluate the sella and craniofacial morphological features in growing patients with palatally displaced canines compared to controls. Materials and methods: Twenty-two subjects with palatally displaced canines were retrospectively selected and compared to 22 controls matched for age and gender. Lateral cephalograms were collected and sagittal and vertical cephalometric variables were measured, together with sella interclinoid distance, sella depth, and sella diameter. The independent samples T-test or Mann-Whitney U-test were used to compare all the variables between the two groups. A Pearson correlation was computed for the craniofacial and sella variables that differed significantly (p < 0.05) between the groups. Results: Patients with palatally displaced canines showed a smaller interclinoid distance and a greater SNA angle than control subjects. The interclinoid distance and the SNA angle were negatively correlated (–0.52, p = 0.017) in the experimental group. Conclusions: Growing patients with palatally displaced canines had smaller sella interclinoid distances and a greater SNA angle than control subjects

    Giant magnons and non-maximal giant gravitons

    Full text link
    We produce the open strings on R×S2\mathbb{R}\times S^{2} that correspond to the solutions of integrable boundary sine-Gordon theory by making use of the NN-magnon solutions provided in \cite{KPV} together with explicit moduli. Relating the two boundary parameters in a special way we describe the scattering of giant magnons with non-maximal Y=0Y=0 giant gravitons and calculate the leading contribution to the associated magnon scattering phase.Comment: 34 pages, 8 figure

    Quantum characterization of superconducting photon counters

    Get PDF
    We address the quantum characterization of photon counters based on transition-edge sensors (TESs) and present the first experimental tomography of the positive operator-valued measure (POVM) of a TES. We provide the reliable tomographic reconstruction of the POVM elements up to 11 detected photons and M=100 incoming photons, demonstrating that it is a linear detector.Comment: 3 figures, NJP (to appear

    Oral health status and periodontitis in Alzheimer's disease patients: A case control Study in a Sicilian rural community

    Get PDF
    Aim. Dementia is a common disorder among the elderly. Alzheimer’s disease (AD) is the most common cause of dementia. In addition to known risk factors (e.g. age and familiarity) of AD, recently it has been suggested a possible promoting role for chronic inflammatory infective diseases. Periodontal disease (PD) is a frequent chronic multi-bacterial infection involving the tissues supporting the teeth; in addition to promoting inflammation locally, the periodontal pathogens possess mechanisms able to influence the systemic balance of inflammatory mediators. Similarly to other systemic diseases (e.g. cardiovascular disease, diabetes, renal diseases and low birth weight), a possible link has been proposed between PD and the development and progression of AD. Aim of the present study was to evaluate the oral health status and the prevalence/severity of PD in a group of patients affected by AD compared to a control group of healthy subjects. Materials and methods. A case-controlled clinical trial was designed to compare patients with AD (Test group - T; n = 16; M: 8; F: 8, range age 64-93 yrs) with healthy controls (Control group - C; n = 16; M: 8; F:8; range age 64-92 yrs). The population study was named ZAP (Zabut Aging Project) and all participants, enrolled in a Sicilian rural community (Sambuca di Sicilia, AG, Italy), were matched for age and sex. Following variables were recorded: smoking and drinking habits, number of teeth, Decayed Missed Filled Teeth scoring (DMFT), measurement of the probing depth (CPI and PSR index). The association between AD and PD, socio-demographic and behavioural-clinical variables was assessed using the χ2 test or Fisher’s exact test, as appropriate. To measure the association level, crude OR and the 95% Confidence Interval (CI) were calculated. Statistical significance of the difference in the average DMFT between cases and controls was assessed using the Student’s t-test. A p value ≤0.05 was considered statistically significant. Results. One patient of T group was a smoker versus four of C group; four T patients were drinker versus two of C group. Seven of T group (43.7%) were totally edentulous, conversely only 2 (12.5%) of controls have the same condition (p=0.04). With respect to oral status, DMFT index was 23.7 ±9.0 in T patients versus 25.2±7.8 in controls (p=0.633). There were no significant differences between T and C groups regarding periodontal index: high PSR and CPI scores (>3) were recorded in 77.8% of AD patients and 46.1% of health cases (p >0.05). A similar distribution among two groups was observed regarding the other investigated variables (e.g. smoking and drinking habits). Conclusions. In this rural Sicilian adult/elderly community, poor oral health is frequent with a DMFT score higher than general population. The obtained data do not support the hypothesis of a major prevalence and severity of PD among AD patients. However, to confirm these preliminary results the recruitment of a wider sample size and further data, regarding proteomic salivary profiles and RT PCR-based microbiological investigation on sub-gingival plaque samples, still need in order to better clarify the role of PD and periodontal pathogens in the AD natural history

    Peripheral giant cell granuloma: immunohistochemical analysis of different markers. Study of three cases

    Get PDF
    El granuloma periférico de células gigantes (GPCG) es una lesión de tejido blando no neoplásica ocasionada por una reacción hiperplásica a consecuencia de un traumatismo o inflamación. Es una lesión reactiva del tejido blando que se desarrolla exclusivamente en la cavidad oral y con una ligera predilección en el sexo femenino. La localización habitual de GPCG es en la región de los premolares y la mucosa de la cresta alveolar edéntula. Se presentan tres casos con GPCG (dos hombres y una mujer) con una edad comprendida entre los 25 y 35 años. Todos los pacientes se trataron con resección quirúrgica y ninguno sufrió recidivas. Con el propósito de determinar el posible origen de las células estromales mononucleares y de las células gigantes multinucleares, las muestras de cada caso se estudiaron mediante inmunohistoquímica (marcadores CD-68, CD-34 y α-1 antitripsina) con el fin de evaluar la expresión del linaje endotelial y del linaje monocito/macrófago. Los resultados inmunohistoquímicos mostraron una marcada positividad difusa de CD-68 en las células estromales mononucleares y en las células gigantes multinucleadas. Estas últimas resultaron ser inmunonegativas para CD-34 y sólo puntualmente positivas para α-1 antitripsina. Estos resultados sugieren que las cιlulas gigantes multinucleares poseen un fenotipo osteoclαstico, proviniendo del linaje monocito/macrσfago, y que no derivan del linaje de las células endoteliales de los capilares. Se establece la importancia de un exhaustivo diagnóstico y de una exéresis quirúrgica completa de la lesión (curetaje óseo) con el propósito de evitar la reabsorción del diente y hueso adyacente
    corecore