466 research outputs found

    Theoretical investigation of equilibrium dynamics in braided gravel beds for the preservation of a sustainable fluvial environment

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    Gravel bars have an important role in the exchange between surface and subsurface waters, in preventing and mitigating riverbank erosion, in allowing the recreational use of rivers, and in preserving fluvial or riparian habitats for species of fishes, invertebrates, plants, and birds. In many cases, gravel bars constitute an important substrate for the establishment and development of ground flora and woody vegetation and guarantee higher plant diversity. A sustainable management of braided rivers should, therefore, ensure their ecological potential and biodiversity by preserving a suitable braiding structure over time. In the present study, we propose an analytical-numerical model for predicting the evolution of gravel bars in conditions of dynamical equilibrium. The model is based on the combination of sediment balance equation and a regression formula relating dimensionless unit bedload rate and stream power. The results highlight the dependence of the evolving sediment particles’ pattern on the ratio of initial macro-bedforms longitudinal dimension to river width, which determines the gradual transition from advective and highly braiding to diffusive transport regime. Specifically, the tendency to maintain braiding and flow bifurcation is associated with equilibrium average bed profiles and, therefore, equilibrium average stream power characterized by the maximum period that does not exceed transverse channel dimension

    Tibial tuberosity derotation: a surgical procedure for realignment of the patellofemoral mechanism

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    We retrospectively reviewed the clinical outcomes of 22 patients (9 men and 13 women) aged 17–42 years, and affected with anterior knee pain. These patients underwent surgical derotation of the tibial tuberosity in the period between September 1992 and December 1993. We describe the details of this new surgical technique to correct a torsional abnormality that has perhaps been underestimated in the past, as a possible cause of anterior knee pain. Follow-up clinical and radiographic controls (average follow-up, 78 months; range 72–87 months) allowed us to document the efficacy of this new procedure as a treatment for anterior knee pain resistant to conservative therapy, in young patients with external hypertorsion of the proximal tibial metaphysis and without significant chondropathology

    The role of the innate immune response in HPV-related oral and oropharyngeal cancer

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    Introduction. During the last 20 years, the incidence of HPV-associated oropharyngeal cancer is increased. Principal actors of the innate immune response against HPV are represented by the TLRs (Toll like receptors). On the other hand different studies have reported that HPV can directly inhibit the functions of the TLRs pathway through interferons (IFNs). There are very few preliminary studies on the role of TLRs mediated HPV clearance in human oncology. Our study aim has been to evaluate whether TLR4 identifies HR-HPV integration state in OSCC. Methods. Protein levels of TLR4 in OSCC were assessed using Immunohistochemistry (IHC). In situ hybridization (ISH) for HPV-DNA detection in morphological context and Pyro-sequencing method have been performed in order to detect viral integration or episomic status. The relationship between TLR expression with or without HPV infection has been elucidated. Results. ISH HPV positive samples have reported lower TLR4 intensity than negative samples and it has confirmed by statistically significant difference (p = .002). There is no statistical correlation between TLR4 intensity and PCR HPV results (p > 0.05). Point-biserial correlation coefficient revealed statistically significant association between TLR4 expression and HR-HPV integration status (p = .0001) and between TLR4 expression index and HR-HPV infection (p = .001). Conclusions. We retain that TLR4 down-regulation is not associated to the histological tumoral grade but rather to HPV-16 infection and to its integration state into the host DNA

    Epigenetic Profiling of Oral Cancer

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    A Novel GAN-Based Anomaly Detection and Localization Method for Aerial Video Surveillance at Low Altitude

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    The last two decades have seen an incessant growth in the use of Unmanned Aerial Vehicles (UAVs) equipped with HD cameras for developing aerial vision-based systems to support civilian and military tasks, including land monitoring, change detection, and object classification. To perform most of these tasks, the artificial intelligence algorithms usually need to know, a priori, what to look for, identify. or recognize. Actually, in most operational scenarios, such as war zones or post-disaster situations, areas and objects of interest are not decidable a priori since their shape and visual features may have been altered by events or even intentionally disguised (e.g., improvised explosive devices (IEDs)). For these reasons, in recent years, more and more research groups are investigating the design of original anomaly detection methods, which, in short, are focused on detecting samples that differ from the others in terms of visual appearance and occurrences with respect to a given environment. In this paper, we present a novel two-branch Generative Adversarial Network (GAN)-based method for low-altitude RGB aerial video surveillance to detect and localize anomalies. We have chosen to focus on the low-altitude sequences as we are interested in complex operational scenarios where even a small object or device can represent a reason for danger or attention. The proposed model was tested on the UAV Mosaicking and Change Detection (UMCD) dataset, a one-of-a-kind collection of challenging videos whose sequences were acquired between 6 and 15 m above sea level on three types of ground (i.e., urban, dirt, and countryside). Results demonstrated the effectiveness of the model in terms of Area Under the Receiving Operating Curve (AUROC) and Structural Similarity Index (SSIM), achieving an average of 97.2% and 95.7%, respectively, thus suggesting that the system can be deployed in real-world applications

    A Troubling Diagnosis of Verrucous Squamous Cell Carcinoma (“the Bad Kind” of Keratosis) and the Need of Clinical and Pathological Correlations: A Review of the Literature with a Case Report

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    Verrucous carcinoma (also known as Ackerman tumor) is an uncommon exophytic low-grade well-differentiated variant of squamous cell carcinoma. This neoplasm typically involves the oral cavity, larynx, genitalia, skin, and esophagus. It is well known for its locally aggressiveness and for its clinically slow-growing behaviour with minimal metastatic potential. Verrucous carcinoma of oral cavity is so closely aligned with the use of snuff and chewing tobacco that it has been called the “snuff dipper's cancer”. Recent studies have proved the role of HPV. The typical clinical presentation of oral verrucous carcinoma has long been known, as its remarkably innocuous appearance and biological behaviour. In this work, we report a review of the scientific literature and describe a troublesome case of oral verrucous cancer

    Asymmetric transmission and anomalous refraction in metal nanowires metasurface

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    Here we investigated the asymmetric transmission and the anomalous refraction introduced by a metasurface of bent gold nanowires. The refraction follows the generalized Snell's law that takes into account the resonant behavior of metallic nanostructures located at the interface between two dielectrics. Measurements performed in the linear optical regime reveal a large sensitivity to the subwavelength features of the gold nanostructures

    HSP 27 aspossible prognostic factor in patients with oral squamous cell carcinoma.

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    Summary. HSP27 belongs to the Heat shock protein (HSP) family, which plays essential functions in cells under physiological conditions and prevents stressinduced cellular damage. The aim of this study was to investigate the biological role of HSP27 in oral tumorigenesis. Materials and methods: Seventy-nine cases of oral squamous cell carcinoma and 10 cases of normal mucosa were analysed for HSP27 expression by immunohistochemistry. Moreover, the western blot analysis was performed on two cases of normal mucosa and five cases of OSCC. Results: Normal oral mucosa showed a suprabasal expression of HSP27. Twenty-four cases of SCC (30.7%) showed a diffuse staining for HSP27, and 48 cases (60.3%) showed instead a decrease in staining, which was diffuse, homogeneous, or with alternation of positive and negative areas in a single tumor (“mosaic” pattern). Only 7 cases of OSCC (7.5%) were completely negative for HSP27. Frequency of lymph node metastases was higher in HSP27-negative tumours (3/7, 42.8%) than in HSP-reduced (16/48, 33.3%) or positive ones (5/26, 19.2%). Regard staging, stages I and II had a higher score than stages III and IV (stage I > stage II > stage III > stage IV). There was also a statistically significant correlation between HSP27 expression and grade: HSP27 expression was reduced in poorly differentiated tumours (P < 0.05). When analysed for prognostic significance, patients with negative/reduced HSP27 expression had poorer survival rates than the group with positive HSP27 expression (P < 0.05). The statistical analysis of these findings showed no significant correlation between HSP27 expression, sex, and tumour size. Conclusion: Cases with reduced expression were more aggressive and poorly differentiated. These data suggest that HSP27 expression may be useful in order to identify cases of oral squamous cell carcinoma with more aggressive and invasive phenotype providing novel diagnostic and prognostic information on individual patient survival with oral cancers

    Targeting oncogenic Src homology 2 domain-containing phosphatase 2 (SHP2) by inhibiting its protein-protein interactions

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    We developed a new class of inhibitors of protein-protein interactions of the SHP2 phosphatase, which is pivotal in cell signaling and represents a central target in the therapy of cancer and rare diseases. Currently available SHP2 inhibitors target the catalytic site or an allosteric pocket but lack specificity or are ineffective for disease-associated SHP2 mutants. Considering that pathogenic lesions cause signaling hyperactivation due to increased levels of SHP2 association with cognate proteins, we developed peptide-based molecules with nanomolar affinity for the N-terminal Src homology domain of SHP2, good selectivity, stability to degradation, and an affinity for pathogenic variants of SHP2 that is 2-20 times higher than for the wild-type protein. The best peptide reverted the effects of a pathogenic variant (D61G) in zebrafish embryos. Our results provide a novel route for SHP2-targeted therapies and a tool for investigating the role of protein-protein interactions in the function of SHP2
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