68 research outputs found

    Effective Mechanical Properties of AlSi7Mg Additively Manufactured Cubic Lattice Structures

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    Lattice structures, whose manufacturing has been enabled by additive technologies, are gaining growing popularity in all the fields where lightweighting is imperative. Since the complexity of the lattice geometries stretches the technological boundaries even of additive processes, the manufactured structures can be significantly different from the nominal ones, in terms of expected dimensions but also of defects. Therefore, the successful use of lattices needs the combined optimization of their design, structural modeling, build orientation, and setup. The article reports the results of quasi-static compression tests performed on BCCxyz lattices manufactured in a AlSi7Mg alloy using additive manufacturing. The results are compared with numerical simulations using two different approaches. The findings show the influence of the relative density on stiffness, strength, and on the energy absorption properties of the lattice. The correlation with the technological feasibility points out credible improvements in the choice of a unit cell with fewer manufacturing issues, lower density, and possibly equal mechanical properties

    Reflectance Confocal Microscopy as an Aid to Dermoscopy to Improve Diagnosis on Equivocal Lesions: Evaluation of Three Bluish Nodules

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    Nodular lesions can be difficult to diagnose under dermoscopy alone, since they often lack specific diagnostic features. Confocal microscopy can be used as an aid to dermoscopy, to increase the diagnostic accuracy on equivocal skin lesions. We report three cases of bluish nodular lesions, difficult to diagnose under dermoscopy alone. Confocal features were very useful in these cases to lead us to the correct diagnosis, recognizing benign versus malignant entities. Histopathology is also reported, with high correspondence compared to the confocal imaging

    Negative Pigment Network Identifies a Peculiar Melanoma Subtype and Represents a Clue to Melanoma Diagnosis: A Dermoscopic Study of 401 Melanomas

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    The dermoscopic descriptor "negative pigment network" (NPN) has been reported in several types of melanocytic and non-melanocytic lesions, although it has a higher frequency of association with melanoma and Spitz naevus. In a study of 401 consecutive melanomas, excluding facial, acral and mucosal locations, the frequency and variability of NPN were investigated, and the results of NPN correlated with clinical and histopathological data. NPN of any extension was found in 27% of melanomas, most frequently invasive and arising from a naevus on the trunk of young subjects. Seven percent of melanomas in the study population showed presence of NPN in more than half of the lesion area; most of these did not show typical dermoscopic melanoma features. The authors propose a new melanoma subtype, in which extensive NPN should be considered as a diagnostic indicator

    Multiphoton Laser Microscopy and Fluorescence Lifetime Imaging for the Evaluation of the Skin

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    Multiphoton laser microscopy is a new, non-invasive technique providing access to the skin at a cellular and subcellular level, which is based both on autofluorescence and fluorescence lifetime imaging. Whereas the former considers fluorescence intensity emitted by epidermal and dermal fluorophores and by the extra-cellular matrix, fluorescence lifetime imaging (FLIM), is generated by the fluorescence decay rate. This innovative technique can be applied to the study of living skin, cell cultures and ex vivo samples. Although still limited to the clinical research field, the development of multiphoton laser microscopy is thought to become suitable for a practical application in the next few years: in this paper, we performed an accurate review of the studies published so far, considering the possible fields of application of this imaging method and providing high quality images acquired in the Department of Dermatology of the University of Modena

    De Novo Skin Neoplasms in Liver-Transplanted Patients: Single-Center Prospective Evaluation of 105 Cases

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    Background and Objectives: Solid-organ transplant recipients (SOTRs) are notably considered at risk for developing cutaneous malignancies. However, most of the existing literature is focused on kidney transplant-related non-melanoma skin cancers (NMSCs). Conflicting data have been published so far on NMSC incidence among liver transplant recipients (LTRs), and whether LTRs really should be considered at lower risk remains controversial. The aim of the present study was to prospectively collect data on the incidence of cutaneous neoplasms in an LTR cohort. Materials and Methods: All LTRs transplanted at the Hepato-Pancreato-Biliary Surgery and Liver Transplantation Unit of Modena University Hospital from October 2015 to June 2021 underwent a post-transplant periodic skin check at the Dermatology Unit according to our institutional integrated care pathway. Data on the presence of cutaneous malignant and premalignant lesions were collected at every timepoint. Results: A total of 105 patients were enrolled in the present study. Nearly 15% of the patients developed cutaneous cancerous and/or precancerous lesions during the follow-up period. Almost half of the skin cancerous lesions were basal cell carcinomas. Actinic keratoses (AKs) were observed in six patients. Four patients developed in situ squamous cell carcinomas, and one patient was diagnosed with stage I malignant melanoma. Otherwise, well-established risk factors for the occurrence of skin tumors, such as skin phototype, cumulative sun exposure, and familial history of cutaneous neoplasms, seemed to have no direct impact on skin cancer occurrence in our cohort, as well as an immunosuppressive regimen and the occurrence of non-cutaneous neoplasms. Conclusions: Close dermatological follow-up is crucial for LTRs, and shared protocols of regular skin checks in this particular subset of patients are needed in transplant centers

    Reflectance confocal microscopy and features of melanocytic lesions: An internet-based study of the reproducibility of terminology

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    Objective: To test the interobserver and intraobserver reproducibility of the standard terminology for description and diagnosis of melanocytic lesions in in vivo confocal microscopy. Design: A dedicated Web platform was developed to train the participants and to allow independent distant evaluations of confocal images via the Internet. Setting: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy. Participants: The study population was composed of 15 melanomas, 30 nevi, and 5 Spitz/Reed nevi. Six expert centers were invited to participate at the study. Intervention: Evaluation of 36 features in 345 confocal microscopic images from melanocytic lesions. Main Outcome Measure: Interobserved and intraobserved agreement, by calculating the Cohen κ statistics measure for each descriptor. Results: High overall levels of reproducibility were shown for most of the evaluated features. In both the training and test sets there was a parallel trend of decreasing κ values as deeper anatomic skin levels were evaluated. All of the features, except 1, used for melanoma diagnosis, including roundish pagetoid cells, nonedged papillae, atypical cells in basal layer, cerebriform clusters, and nucleated cells infiltrating dermal papillae, showed high overall levels of reproducibility. However, less-than-ideal reproducibility was obtained for some descriptors, such as grainy appearance of the epidermis, junctional thickening, mild atypia in basal layer, plump bright cells, small bright cells, and reticulated fibers in the dermis. Conclusion: The standard consensus confocal terminology useful for the evaluation of melanocytic lesions was reproducibly recognized by independent observers. ©2009 American Medical Association. All rights reserved.This study was supported in part by a grant from the Istituto Superiore di Sanità (ISS), Italy (project No. 527/B/3A/4).Peer Reviewe

    Benefits of polarized versus nonpolarized dermoscopy

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    Dermoscopy is a widely diffuse tool that allows a better noninvasive diagnosis of pigmented and nonpigmented skin lesions, visualizing magnified images of subsurface structures. The light source can be nonpolarized or polarized, the latter being a more recent technique acquisition. Papers from the last decade focused on the appreciable differences between the two techniques. In general, by polarized dermoscopy the visualization of deeper and vascular structures is more attainable, but the main issue is the quality of the image, influencing both diagnostic accuracy and confidence level, regardless of the lighting technique. A terminology based on polarized dermoscopy is still missing, requiring further consensus-based studie

    Spitz nevi

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    The Spitz–Reed nevi family includes benign melanocytic tumors, generally acquired, characterized by a wide variety of clinical presentations, dermoscopic pattern and histopathologic features. The clinical differential diagnosis with melanoma is often considered due to its alarming clinical presentation. Spitz nevi are often described as pinkish-red papule suddenly arising in very young people, whereas Reed ones are commonly seen on the legs of adult patients. In both cases, patients often refer that the lesion suddenly appeared and is quickly growing. In this chapter, and often in the daily clinical experience, these two entities are joined in the same group, showing common histopathologic findings. © Springer-Verlag Berlin Heidelberg 2012.The Spitz–Reed nevi family includes benign melanocytic tumors, generally acquired, characterized by a wide variety of clinical presentations, dermoscopic pattern and histopathologic features. The clinical differential diagnosis with melanoma is often considered due to its alarming clinical presentation. Spitz nevi are often described as pinkish-red papule suddenly arising in very young people, whereas Reed ones are commonly seen on the legs of adult patients. In both cases, patients often refer that the lesion suddenly appeared and is quickly growing. In this chapter, and often in the daily clinical experience, these two entities are joined in the same group, showing common histopathologic findings
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