Epiluminescence microscopy: A new approach to in vivo detection of sarcoptes scabiei

Background: The usual methods of scabies diagnosis include microscopic identification of the mites and their eggs and feces in skin scrapings. In many cases, the results of microscopic examination can be negative owing to the low number of parasites present in the cornified layer. Epiluminescence microscopy (ELM) is an in vivo technique that allows a detailed inspection of the skin, from the surface to the superficial papillary dermis. This is where the scabies mite lives. In this study, we evaluate the applicability and the usefulness of ELM for in vivo diagnosis of scabies. Observations: Sixty-five (93%) of 70 cases of scabies showed small, dark, triangular structures at the sites examined with ELM. A subtle linear segment seen below the base of the triangle was made visible by the presence of small air bubbles. Together, both structures re sembled a jet with contrail. On traditional microscopic examination of the scrapings, we verified that the triangular structure corresponded to the pigmented anterior section of the mite in all cases. The linear segment observed on ELM was thought to be the burrow of the mite along with its eggs and fecal pellets. The cases in which the results of a first ELM examination were negative demonstrated positive results on a second ELM examination carried out 20 days later. Conclusion: Epiluminescence microscopy is a very useful tool for in vivo diagnosis of scabies because it permits Sarcoptes scabiei detection in only a few minutes, with no discomfort to the patient and with a very low number of false-negative results

Innovative mass-damping-based approaches for seismic design of tall buildings

Mass damping is a well known principle for the reduction of structural vibrations and applied in tall building design in a variety of configurations. With mass usually small (around 1% of building mass), the properly “tuned” mass damper (TMD) shows great effectiveness in reducing wind vibrations, but minor advantages under earthquake excitations. The above limitation can be surpassed by utilizing relatively large mass TMD. For this purpose, two different solutions are here proposed. In both cases, the idea is to separate the building into two or more parts, thus allowing for a relative motion between them, and activating the mass damping mechanism. In the first solution, the building is subdivided along elevation into an upper and a lower structure, separated by means of an intermediate isolation system (IIS). In the second solution, by revisiting the classical mega-frame typology, the exterior full-height structure provides the global strength and stiffness, and secondary structures, extending between two transfer levels, are physically detached from the main structure at each floor and isolated at transfer level. Simplified lumped-mass models are developed for illustrating the dynamic behaviour of the two solutions and carrying out parametric analyses. Procedures for deriving optimum values of design parameters are also proposed and compared to the parametric study

Improving the Seismic Response of Tall Buildings: From Diagrid to Megastructures and Mega-Subcontrol Systems

Background: Diagrid structures, widely used for the tall buildings of the third millennium, are characterized by a very effective behaviour in the elastic field due to the grid triangulation. In particular, under horizontal actions, axial forces and deformations mainly arise in the structural members of the diagrid, thus resulting in the reduction of the shear lag effect and racking deformations. The response to incremental horizontal actions beyond the plastic threshold, however, shows a poor plastic redistribution capacity, with consequent low values of global ductility, in spite of a significant design overstrength. Objective: In this paper, it is proposed to exploit the high elastic efficiency of the diagrid type and use a vibration control system, based on mass damping mechanism with large mass ratios, to reduce a priori the inelastic demands due to seismic actions. Methods: Starting from the analysis of the seismic behavior of archetype diagrid buildings, a case study is selected to assess the effectiveness of the proposed motion-based design approach. For this purpose, the diagrid is first transformed into a megastructure (MS) configuration by densifying the diagonal elements at the most stressed corner areas and transfer floors, suitably chosen. Then, the exterior mega-frame is detached from interior sub-structures, thus allowing for a relative motion between the two structural portions according to a “mega-sub-structure control system” (MSCS), which activates the mass damping mechanism. Results: Time-history analyses carried out on simplified lumped-mass models confirm the effectiveness of the proposed strategy in reducing the seismic response. Conclusion: Finally, the practical feasibility of the MSCS and engineering solutions for the relevant structural organization are discussed

Dermoscopy of uncommon variants of dermatofibrosarcoma protuberans

Darier-Ferrand dermatofibrosarcoma protuberans (DFSP) is a locally aggressive fibrohistiocytic tumour with a low metastatic potential.(1) Because of its rarity, slow progression and lack of early clinical clues, the diagnosis of DFSP is often delayed. Classical DFSP clinically appeared like an indurated, irregularly-shaped plaques exhibiting flesh to reddish-brown colour. Some lesions also showed thin teleangectasia on the surface (Fig. 1, a). This article is protected by copyright. All rights reserved

Moving mass over a viscoelastic system: asymptotic behaviours and insights into nonlinear dynamics

Moving masses are of interest in many applications of structural dynamics, soliciting in the last decades a vast debate in the scientific literature. However, despite the attention devoted to the subject, to the best of the authors’ knowledge, there is a lack of analysis about the fate of a movable mass when it rolls or slips with friction on a structure. With the aim of elucidating the dynamics of the simplest paradigm of this system and to investigate its asymptotic response, we make reference to a two-degree-of-freedom model made of an elastically vibrating carriage surmounted by a spherical mass, facing the problem both theoretically and experimentally. In case of linear systems, the analytical solutions and the laboratory tests performed on ad hoc constructed prototypes highlighted a counterintuitive asymptotic dynamics, here called binary: in the absence of friction at the interface of the bodies’ system, the mass holds its initial position or, if nonzero damping acts, at the end of the motion it is in a position that exactly recovers the initial relative distance carriage–sphere. While the first result might be somewhat obvious, the second appears rather surprising. Such a binary behaviour is also confirmed for a Duffing-like system, equipped with cubic springs, while it can be lost when non-smooth friction phenomena occur, as well as in the case of elastic springs restraining the motion of the sphere. The obtained analytical results and the numerical findings, also confirmed by experimental evidences, contribute to the basic understanding of the role played by the damping parameters governing the systems’ dynamics with respect to its asymptotic behaviour and could pave the way for designing active or passive vibration controllers of interest in engineering

Clinical and dermatoscopic criteria for the preoperative evaluation of cutaneous melanoma thickness

Background: Melanoma thickness measured according to the Breslow method is used to determine surgical margin and in patient selection for sentinel node biopsy. Previous studies did not confirm the reliability of melanoma palpability for clinical prediction of tumor thickness. Recently we reported the usefulness of epiluminescence microscopy (dermatoscopy) for in vivo detection of the phases of melanoma progression, as well as tumor depth. Objective: Our purpose was to determine whether the combination of clinical and dermatoscopic criteria could increase the accuracy in preoperative evaluation of melanoma thickness with respect to the clinical elevation and dermatoscopic assessments considered separately. Methods: In a blind retrospective study, 122 cutaneous melanomas were studied to evaluate the presence of several clinical and dermatoscopic criteria and their relation with the histologic thickness. An algorithm of combined criteria was constructed and statistically assessed. Results: Combinations of palpability, diameter of more than 15 mm, pigment network, gray-blue areas, and atypical vascular pattern allowed correct prediction of thickness in 89% of melanomas when categorized in two groups of less than 0.76 mm and more than 0.75 mm thickness, compared with 75% using palpability, and 80% using dermatoscopic criteria. Lower values were obtained in the further subdivision of melanomas into groups of 0.76 to 1.5 mm and more than 1.5 mm thickness. Conclusion: The combination of clinical and dermatoscopic criteria is a more precise guide for the preoperative evaluation of melanoma thickness than either is alone. However, further studies are needed to verify its applicability in establishing the surgical approach to cutaneous melanoma

Epiluminescence microscopy: Criteria of cutaneous melanoma progression

Background: Cutaneous melanoma develops through a series of evolutionary steps (intraepidermal, radial, and vertical growth phases) that are traceable in specific histologic features. Epiluminescence microscopy (ELM) is an in vivo technique that enables the visualization of morphologic structures in pigmented lesions correlated with specific histologic architectural characteristics. Many ELM criteria associated with cutaneous melanoma have been described, but their correlation with tumor progression has not yet been established. Objective: In this preliminary study our purpose was to explore the possibility of recognizing ELM criteria that allow the in vivo detection of the various phases of melanoma progression as well as tumor depth. Methods: Seventy-two cutaneous melanomas (41 'thin' melanomas [TnM], 0.75 mm thickness) were investigated with ELM for the presence of nine standard ELM criteria; their significance was determined by calculating the chi-square test of independence. Results: A significant association is found between the presence of pigment network and TaM and between the presence of gray-blue areas, vascular pattern, and TkM. Moreover, pigment network plus radial streaming is the most significant association of ELM criteria in TnM, whereas gray-blue areas plus vascular pattern is the greatest in TkM. Conclusion: This study shows a good correlation between certain ELM criteria and the histologic architecture of cutaneous melanoma for a preoperative evaluation of the tumor thickness. Further investigation is needed for verifying on a larger number of cases our pilot estimates of sensitivity and specificity of ELM criteria in thin and thick melanomas

Ultrasound-Responsive Nrf2-Targeting siRNA-Loaded Nanobubbles for Enhancing the Treatment of Melanoma

The siRNA-mediated inhibition of nuclear factor E2-related factor 2 (Nrf2) can be an attractive approach to overcome chemoresistance in various malignant tumors, including melanoma. This work aims at designing a new type of chitosan-shelled nanobubble for the delivery of siRNA against Nrf2 in combination with an ultrasound. A new preparation method based on a water–oil–water (W/O/W) double-emulsion was purposely developed for siRNA encapsulation in aqueous droplets within a nanobubble core. Stable, very small NB formulations were obtained, with sizes of about 100 nm and a positive surface charge. siRNA was efficiently loaded in NBs, reaching an encapsulation efficiency of about 90%. siNrf2-NBs downregulated the target gene in M14 cells, sensitizing the resistant melanoma cells to the cisplatin treatment. The combination with US favored NB cell uptake and transfection efficiency. Based on the results, nanobubbles have shown to be a promising US responsive tool for siRNA delivery, able to overcome chemoresistance in melanoma cancer cells

Epiluminescence microscopy for the diagnosis of doubtful melanocytic skin lesions: Comparison of the ABCD rule of dermatoscopy and a new 7-point checklist based on pattern analysis

Objective: To compare the reliability of a new 7-point checklist based on simplified epiluminescence microscopy (ELM) pattern analysis with the ABCD rule of dermatoscopy and standard pattern analysis for the diagnosis of clinically doubtful melanocytic skin lesions. Design: In a blind study, ELM images of 342 histologically proven melanocytic skin lesions were evaluated for the presence of 7 standard criteria that we called the 'ELM 7-point checklist.' For each lesion, 'overall' and 'ABCD scored' diagnoses were recorded. From a training set of 57 melanomas and 139 atypical non-melanomas, odds ratios were calculated to create a simple diagnostic model based on identification of major and minor criteria for the '7-point scored' diagnosis. A test set of 60 melanomas and 86 atypical non-melanomas was used for model validation and was then presented to 2 less experienced ELM observers, who recorded the ABCD and 7-point scored diagnoses. Settings: University medical centers. Patients: A sample of patients with excised melanocytic lesions. Main Outcome Measures: Sensitivity, specificity, and accuracy of the models for diagnosing melanoma. Results: From the total combined sets, the 7-point checklist gave a sensitivity of 95% and a specificity of 75% compared with 85% sensitivity and 66% specificity using the ABCD rule and 91% sensitivity and 90% specificity using standard pattern analysis (overall ELM diagnosis). Compared with the ABCD rule, the 7-point method allowed less experienced observers to obtain higher diagnostic accuracy values. Conclusions: The ELM 7-point checklist provides a simplification of standard pattern analysis because of the low number of features to identify and the scoring diagnostic system. As with the ABCD rule, it can be easily learned and easily applied and has proven to be reliable in diagnosing melanoma