Structured Deformations of Continua: Theory and Applications

The scope of this contribution is to present an overview of the theory of structured deformations of continua, together with some applications. Structured deformations aim at being a unified theory in which elastic and plastic behaviours, as well as fractures and defects can be described in a single setting. Since its introduction in the scientific community of rational mechanicists (Del Piero-Owen, ARMA 1993), the theory has been put in the framework of variational calculus (Choksi-Fonseca, ARMA 1997), thus allowing for solution of problems via energy minimization. Some background, three problems and a discussion on future directions are presented.Comment: 11 pages, 1 figure, 1 diagram. Submitted to the Proceedings volume of the conference CoMFoS1

Diffuse Cohesive Energy in Plasticity and Fracture

In this paper we anticipate some results of a work in progress (Del Piero et al., 2012), in which the phenomena of fracture and yielding are described by a cohesive energy model, and fracture is regarded as a consequence of an extreme localization of the inelastic deformation. We first study a local model, which is successful in describing a number of aspects of the experimentally observed response, but fails to describe the phenomenon of strain softening. Indeed the model’s prediction is that, just after its appearance, the inelastic deformation localizes, growing in an uncontrolled way and determining a catastrophic rupture. A more gradual growth is obtained by introducing a non-local energy term. Some numerical experiments show the great flexibility of the improved model: depending on the analytical shape assumed for the cohesive energy, the non-local model describes different types of response, such as yielding without fracture, ductile fracture with and without strain softening, and brittle fracture

Targets for the Treatment of Breast Cancer

The completion of the human genome sequence provides unique opportunities to identify new molecular targets for a variety of diseased conditions, especially for neoplastic diseases. Breast cancer is an ideal disease for the implementation of the recently developed, sophisticated genomic technologies, which permit the study of expression of many genes or proteins simultaneously, an approach known as molecular profiling. This approach is considered a major step forward in the development of new drugs that are more effective and less toxic than the current generation of antitumor agents. In this paper, we briefly review the current and future genomics technologies, such as DNA microarrays and proteomics techniques, and their use in the identification of new molecular targets for the treatment of breast cancer. We also discuss the challenge associated with the development of bioinformatics tools to analyze the massive number of data points generated by these technologies. Proof of principle is now emerging, demonstrating that selective agents against abnormal or mutated gene products can indeed be useful in the treatment of cancer. However, despite heavy investment in genomics research by the pharmaceutical industry, the full impact of genomics on drug discovery has yet to be fully demonstrated

Nasal tip sutures: how to control shape and orientation in rhinoplasty

Nasal tip surgery is universally recognized as the most challenging part of the rhinoplasty procedure. "The tip makes the nose”. Narrowing the anatomically complex alar cartilages can lead to functional and aesthetic unfavourable outcomes. A thorough understanding of the ideal surface aesthetics and contours and spatial relationships of the structures of the nose tip is mandatory. In primary rhinoplasty, a very large percentage of visible tip deformities involve two major areas: the domes and the lateral crura. Suture techniques have the potential to modify the position, shape and definition of the tip. However, even sutures may result in changes beyond the main goals for which they are placed. The final suture effects are influenced by factors such as forces intrinsic to the cartilages, the degree of suture tightening, and limitations posed by the soft-tissue attachments. The closed delivery approach is our favourite. In a step-by-step fashion, first the medial pillar of the tripod should be addressed, establishing stable and strong tip support and basic dome projection symmetry. Subsequently and in our experience, in a standard procedure shaping lateral crura and domes, using reversible techniques that preserve structural integrity of the rimstrip, would be advisable. One of the main goals is not only to narrow the tip but to change the angle of rotation of the lateral crus surface in relation to the sagittal upper septal margin. Once marked the new dome defining point, with a variable combination of the lateral crural steal technique, sutures such as cranial tip sutures (CTS) and hemitransdomal sutures (HTS) might produce the needed outcome of everting and rotating the caudal margin of the lateral crura above the cranial edge. These sutures can gradually increase domal convexity and reduce lateral crura convexity. Additional dome equalization suture can guarantee more symmetry and then one or more lateral crural spanning sutures help in achieving supplementary eversion of the lateral crus. After establishing adequate projection, the tip rotation or position sutures are placed between the cranial edge of intermediate crura and the dorsal septum. The personal association of suture techniques is presented in this study and the long-term subjective and objective results are discussed along with the pros and cons

The challenging Silent sinus syndrome

The Silent sinus syndrome (SSS), first described in 1964 by Montgomery, is considered a relatively rare pathological entity, but it is presumably underdiagnosed and underreported. Terms such as imploding antrum and chronic maxillary atelectasis (CMA) have interchangeably been used to describe this syndrome, even though CMA has been postulated to represent either a different entity or a stage of evolution of the same disease. Bilateral involvement has been documented in a limited number of cases. Silent ethmoid sinus and silent frontal sinus syndromes have been described. The prevalent initial presentation is facial asymmetry with progressive “silent” painless unilateral enophthalmos and hypoglobus, and rarely diplopia. Isolated maxillary sinus hypoplasia must be differentiated. The etiopathogenesis is poorly understood and still under debate. According to the diagnostic criteria, SSS should spontaneously develops in absence of previous trauma or surgery. Secondary SSS to trauma or surgery, or to other causes like inflammation or tumor, has been documented in literature. The diagnosis relies on the CT, which typically shows unilateral hypoplastic and opacified maxillary sinus with inward bowing and remodeling of the sinus walls and inferior displacement of the orbital floor, an enlarged retroantral fat pad, a lateralized uncinate process, and a blocked ostiomeatal complex. The treatment of SSS aims at restoring the eye position and orbital floor height, to prevent progression of enophthalmos, to restore ventilation and drainage of the sinus. These objectives are achieved in single or two-stage surgery. The timing for management of the orbital floor is still under debate.The universally accepted treatment is surgical and usually accomplished by endoscopic sinus surgery. Associated middle turbinate hypertrophy and septal deviation must be previously addressed. Precise and gentle endoscopic removal of the obstruction of the ethmoid infundibulum, simply performing an inferior posteroanterior uncinectomy, since the uncinate process has constantly been found atelectatic and adherent to the lateral nasal wall, can reestablish the patency of the natural maxillary ostium. In our experience, following middle meatal antrostomy, long-term observation with staged orbital surgery, if required, is recommended. In this study, we present our cases with a focus on surgical stratagems developed in order to reduce the risk of injuring the orbit and to achieve long-lasting results

Nasal tip sutures: how to control shape and orientation in rhinoplasty

Nasal tip surgery is universally recognized as the most challenging part of the rhinoplasty procedure. "The tip makes the nose”. Narrowing the anatomically complex alar cartilages can lead to functional and aesthetic unfavourable outcomes. A thorough understanding of the ideal surface aesthetics and contours and spatial relationships of the structures of the nose tip is mandatory. In primary rhinoplasty, a very large percentage of visible tip deformities involve two major areas: the domes and the lateral crura. Suture techniques have the potential to modify the position, shape and definition of the tip. However, even sutures may result in changes beyond the main goals for which they are placed. The final suture effects are influenced by factors such as forces intrinsic to the cartilages, the degree of suture tightening, and limitations posed by the soft-tissue attachments. The closed delivery approach is our favourite. In a step-by-step fashion, first the medial pillar of the tripod should be addressed, establishing stable and strong tip support and basic dome projection symmetry. Subsequently and in our experience, in a standard procedure shaping lateral crura and domes, using reversible techniques that preserve structural integrity of the rimstrip, would be advisable. One of the main goals is not only to narrow the tip but to change the angle of rotation of the lateral crus surface in relation to the sagittal upper septal margin. Once marked the new dome defining point, with a variable combination of the lateral crural steal technique, sutures such as cranial tip sutures (CTS) and hemitransdomal sutures (HTS) might produce the needed outcome of everting and rotating the caudal margin of the lateral crura above the cranial edge. These sutures can gradually increase domal convexity and reduce lateral crura convexity. Additional dome equalization suture can guarantee more symmetry and then one or more lateral crural spanning sutures help in achieving supplementary eversion of the lateral crus. After establishing adequate projection, the tip rotation or position sutures are placed between the cranial edge of intermediate crura and the dorsal septum. The personal association of suture techniques is presented in this study and the long-term subjective and objective results are discussed along with the pros and cons

The challenging Silent sinus syndrome

The Silent sinus syndrome (SSS), first described in 1964 by Montgomery, is considered a relatively rare pathological entity, but it is presumably underdiagnosed and underreported. Terms such as imploding antrum and chronic maxillary atelectasis (CMA) have interchangeably been used to describe this syndrome, even though CMA has been postulated to represent either a different entity or a stage of evolution of the same disease. Bilateral involvement has been documented in a limited number of cases. Silent ethmoid sinus and silent frontal sinus syndromes have been described. The prevalent initial presentation is facial asymmetry with progressive “silent” painless unilateral enophthalmos and hypoglobus, and rarely diplopia. Isolated maxillary sinus hypoplasia must be differentiated. The etiopathogenesis is poorly understood and still under debate. According to the diagnostic criteria, SSS should spontaneously develops in absence of previous trauma or surgery. Secondary SSS to trauma or surgery, or to other causes like inflammation or tumor, has been documented in literature. The diagnosis relies on the CT, which typically shows unilateral hypoplastic and opacified maxillary sinus with inward bowing and remodeling of the sinus walls and inferior displacement of the orbital floor, an enlarged retroantral fat pad, a lateralized uncinate process, and a blocked ostiomeatal complex. The treatment of SSS aims at restoring the eye position and orbital floor height, to prevent progression of enophthalmos, to restore ventilation and drainage of the sinus. These objectives are achieved in single or two-stage surgery. The timing for management of the orbital floor is still under debate.The universally accepted treatment is surgical and usually accomplished by endoscopic sinus surgery. Associated middle turbinate hypertrophy and septal deviation must be previously addressed. Precise and gentle endoscopic removal of the obstruction of the ethmoid infundibulum, simply performing an inferior posteroanterior uncinectomy, since the uncinate process has constantly been found atelectatic and adherent to the lateral nasal wall, can reestablish the patency of the natural maxillary ostium. In our experience, following middle meatal antrostomy, long-term observation with staged orbital surgery, if required, is recommended. In this study, we present our cases with a focus on surgical stratagems developed in order to reduce the risk of injuring the orbit and to achieve long-lasting results

Trend of decreasing length of cervical cone excision during the last 20 years

OBJECTIVE: The aim of the present investigation was to evaluate the cervical conizations performed in the last 20 years in a single institution, with a particular interest in analyzing the trend of the length of cone excisions.PATIENTS AND METHODS: A retrospective cohort study of women who underwent a CO2-laser cervical conization between January 1996 and December 2015. Cytological abnormalities on referral pap smear, colposcopic findings and pertinent clinical and socio-demographic characteristics of each woman were collected. In particular, the length of cone specimen was evaluated, taking into account all the factors potentially influencing the length of excision.RESULTS: A total of 1270 women who underwent cervical conization from January 1996 to December 2015 were included in the analysis. A mean cone length of 15.1 \ub1 5.7 mm was reported, and we observed a significant decrease in the length of cone excisions over the whole study period. Age (rpartial = 0.1543, p < 0.0001), see & treat procedure (rpartial = -0.1945, p < 0.0001) and grade II colposcopic findings (rpartial = 0.1540, p < 0.0001) were significantly associated with the length of cone excision on multivariate analysis.CONCLUSIONS: In the last 20 years, a significant decrease in the length of cone excision was observed. In our opinion, this can be due to the acquired awareness by the gynecologists of the potential disadvantages of wide cone excision in term of adverse obstetric outcomes in future pregnancies

Masonry behaviour and modelling

In this Chapter we present the basic experimental facts on masonry materials and introduce simple and refined models for masonry. The simple models are essentially macroscopic and based on the assumption that the material is incapable of sustaining tensile loads (No-Tension assumption). The refined models account for the microscopic structure of masonry, modeling the interaction between the blocks and the interfaces.(undefined