INDAGINI TEORICHE E SPERIMENTALI SU PARETI SISMICHE IN ACCIAIO

La memoria riguarda il comportamento di pannelli sottili in acciaio utilizzati come pareti di controvento. Per tali sistemi sono previsti due tipi fondamentali di utilizzo: come elementi dissipativi e irrigidenti;come elementi irrigidenti. Il primo caso riguarda pannelli dotati di robusti irrigidimenti, tali da determinare lo snervamento delle lastre costituenti il pannello prima dell’insorgere di fenomeni di instabilità. Tale tipologia è stata utilizzata prevalentemente in Giappone. La tendenza ad adottare pannelli sottili, per i quali l’instabilità avviene in campo elastico, si è sviluppata prevalentemente negli USA ed in Canada, ove attraverso indagini sperimentali si è constatato il notevole contributo dovuto alle riserve in campo post critico dei pannelli. Anche i risultati sperimentali ottenuti dagli autori evidenziano le notevoli riserve di resistenza di tali pannelli in campo post-critico, cosicché oggi è ampliamente plausibile l’introduzione nel progetto di tali elementi strutturali soggetti ad instabilità per azioni sismiche modeste. Gli studi condotti dagli autori hanno riguardato il comportamento di tali pannelli sottili in acciaio sottoposti a forze orizzontali, sviluppando indagini teoriche e sperimentali. La sperimentazione effettuata conferma che in campo post-critico si attivano bande diagonali di trazione, rendendo le riserve di resistenza cospicue; tuttavia i modelli FEM, sviluppati in ambito non lineare, non consentono di riprodurre il comportamento del sistema nella fase iniziale del carico. Nella presente nota si riporta una sintesi delle indicazioni normative e dei risultati ottenuti dagli autori nelle precedenti esperienze, proponendo un chiave di lettura sintetica per prevedere il comportamento di tali sistemi

Modeling Fickian Diffusion in Asphalt Concrete Pavement

The objective of this study is to determine whether exposing an asphaltic roadway to standing liquid water for a duration of twelve hours will cause sufficient moisture penetration to induce deterioration of the roadway. A mathematical model based on mass conservation was applied for the purpose of predicting the diffusivity of moisture into the roadway. The result was then used in a computer simulation to model the temporal and spatial distribution of moisture. In order to execute the simulation, it was necessary to determine the diffusivity of moisture in asphalt concrete. To this end, an experiment was conducted to find the change in mass over time of laboratory samples of asphalt concrete exposed to water on only one face. The procedure for executing this experiment was developed and explained as a part of the research program. The experimental data were shown to be statistically valid, and the resulting diffusivity of moisture in asphalt concrete was found to be 5.976E-5 cm^2/hr. This value was applied within a finite element code for modeling Fick’s Second Law to predict the spatial and temporal distribution of moisture within a representative roadway. Three scenarios were modeled: an undamaged asphalt concrete roadway, an asphalt roadway with a partial crack through the asphalt layer, and an asphalt roadway with a crack extending entirely through the asphalt roadway and into the base layer. On the basis of the results predicted by the model, it was concluded that an asphalt roadway is likely to experience significant damage due to moisture penetration over a twelve hour period only in the case where the crack runs entirely through the asphalt concrete layer and into the base material. This conclusion is based on the extremely small value of experimentally observed diffusivity of moisture in asphalt concrete

Implant-Based Breast Reconstruction after Risk-Reducing Mastectomy in BRCA Mutation Carriers: A Single-Center Retrospective Study

Women with BRCA gene mutations have a higher lifetime risk of developing breast cancer. Furthermore, cancer is usually diagnosed at a younger age compared to the wild-type counterpart. Strategies for risk management include intensive surveillance or risk-reducing mastectomy. The latter provides a significant reduction of the risk of developing breast cancer, simultaneously ensuring a natural breast appearance due to the preservation of the skin envelope and the nipple-areola complex. Implant-based breast reconstruction is the most common technique after risk-reducing surgery and can be achieved with either a submuscular or a prepectoral approach, in one or multiple stages. This study analyzes the outcomes of the different reconstructive techniques through a retrospective review on 46 breasts of a consecutive, single-center case series. Data analysis was carried out with EpiInfo version 7.2. Results of this study show no significant differences in postoperative complications between two-stage tissue expander/implant reconstruction and direct-to-implant (DTI) reconstruction, with DTI having superior aesthetic outcomes, especially in the prepectoral subgroup. In our experience, the DTI prepectoral approach has proven to be a safe and less time-consuming alternative to the submuscular two-stage technique, providing a pleasant reconstructed breast and overcoming the drawbacks of subpectoral implant placement

BIOACTIVE MOLECULES FROM MARINE INVERTEBRATE ORGANISMS AS POTENTIAL TOOLS IN RESTORATION PROCEDURES

In the last decades molecular biology has provided innovative approaches in order to set up specific protocols for the conservation and restoration of cultural assets. In this study, which falls within the so called field of Blue-biotechnology, new bio-reactive peptides isolated from marine invertebrate organisrns (Cnidaria and Molluscs) were tested aim to bio-cleaning (proteolytic- peptides) the surfaces or to control (antimicrobial-peptides) the colonization of historic-artistic manufacts by fungi or bacteria. Particularly, the proteolytic-peptides showed hydrolytic activity, specific for animal-glue, in a range of temperatures of 4-37°C; than acting without heating the surface, by a contro Iled procedure and avoiding damages to the constitutive materials, ali criteria required for conservation /restoration procedures. These hydrolases allow to carry out the removal of the protein layers in a controlled way, acting at the same temperature of the environment where the objects are restored (19-25.5 0C). lnstead, the antirnicrobial-peptides have been tested on a plethora of fungi and bacteria colonies and a specific activity, against Micrococcus spp., have been showed. We are testing the antimicrobial-peptides as a "biologica! biocide" in order to protect both organic and inorganic substrates. We hypothesize that the use of these molecules will give an important contribution to the development of innovative and efficient technologies concerning bio-cleaning and antimicrobial growth protocols, according to conservative restoration procedures

Identification of antimicrobial peptides in the gonad of European sea bass males and females

In vertebrates, the gonad is considered an immunologically privileged site as it triggers lower immune responses aiming to avoid germ cell damage. In fish,several studies reported that leucocytes show conditioned immune response and modulate some reproductive functions, allowing the pathogen to establish chronic and latent infections into reproductive organs. In mammals, antimicrobial peptides (AMPs) have recently been recognised as important effectors in male reproductive tract immunity. In fish, AMPs are increasingly recognized as a critical first line of defence against many pathogens as bacteria, fungi, virus, protozoa and even tumour cells. We have recently determined that the European sea bass (Dicentrarchus labrax) gonad showed antimicrobial activity and constitutively expressed different AMPs genes previously characterized in the immune response. However, it is possible that gonadal specific AMPs play an important role in gonad immune responses, as occurs in mammals. The present study is an attempt to identify and characterize molecules having antimicrobial activity against bacteria and fungi, from the gonad of mature European sea bass males and females. Our results show a very different profile of active AMPs between sexes, suggesting the existence of different AMPs in males and females. However, further characterization of isolated peptides is needed to fully characterize the molecules and determine their role upon infection

Extended Overview of Ocular Phenotype with Recent Advances in Hypohidrotic Ectodermal Dysplasia

The term ectodermal dysplasias (EDs) describes a heterogeneous group of inherited developmental disorders that affect several tissues of ectodermal origin. The most common form of EDs is hypohidrotic ectodermal dysplasia (HED), which is characterized by hypodontia, hypotrichosis, and partial or total eccrine sweat gland deficiency. HED is estimated to affect at least 1 in 17,000 people worldwide. Patients with HED have characteristic facies with periorbital hyperpigmentation, depressed nasal bridge, malar hypoplasia, and absent or sparse eyebrows and eyelashes. The common ocular features of HED include madarosis, trichiasis, and ocular chronic surface disease due to dry eye syndrome, which manifests clinically with discomfort, photophobia, and redness. Dry eye is common in HED and results from a combination of ocular surface defects: mucus abnormalities (abnormal conjunctival mucinous glands), aqueous tear deficiency (abnormalities in the lacrimal gland) and lipid deficiency (due to the partial or total absence of the meibomian glands; modified sebaceous glands with the tarsal plate). Sight-threatening complications result from ocular surface disease, including corneal ulceration and perforation with subsequent corneal scarring and neovascularization. Rare ocular features have been reported and include bilateral or unilateral congenital cataracts, bilateral glaucoma, chorioretinal atrophy and atresia of the nasolacrimal duct. Recognition of the ocular manifestations of HED is required to perform clinical surveillance, instigate supportive and preventative treatment, and manage ocular complications