Influence of the Extrinsic Curvature on 2D Nematic Films

Nematic interfaces are thin fluid films, ideally two-dimensional, endowed with an in-plane degenerate nematic order. In this letter we examine a generalisation of the classical Plateau problem to an axisymmetric nematic interface bounded by two coaxial parallel rings. The equilibrium interface shape results from the competition between surface tension, which favours the minimization of the interface area, and the nematic elasticity which instead promotes the alignment of the molecules along a common direction. We find two classes of equilibrium solutions with intrinsically uniform alignments: one in which the molecules are aligned along the meridians, the other along parallels. Depending on two parameters, one geometric and the other constitutive, the Gaussian curvature of the equilibrium interface may be negative, vanishing or positive. The stability of these equilibrium configurations is investigated

Hydrodynamic theory for nematic shells: the interplay among curvature, flow and alignment

We derive the hydrodynamic equations for nematic liquid crystals lying on curved substrates. We invoke the Lagrange-Rayleigh variational principle to adapt the Ericksen-Leslie theory to two-dimensional nematics in which a degenerate anchoring of the molecules on the substrate is enforced. The only constitutive assumptions in this scheme concern the free-energy density, given by the two-dimensional Frank potential, and the density of dissipation which is required to satisfy appropriate invariance requirements. The resulting equations of motion couple the velocity field, the director alignment and the curvature of the shell. To illustrate our findings, we consider the effect of a simple shear flow on the alignment of a nematic lying on a cylindrical shell

Interactive freehand sketching as the means for online communication of design intent in conceptual design conducted by Brainwriting

AbstractSketching is becoming an irrelevant activity of engineering studies. The availability of many software that aids designers in all phases of design, not only analytic but synthetic, push technicians, designers to use such tools, giving up the employment of a simple pencil and eraser on a sheet of paper. The productivity of software tools is obliged to speed and manage the whole design process; even freehand sketching remains the fundamental means to communicate the first ideas immediately. During Brainwriting sessions, the ability to explain by sketches first elaborations of a possible solution, that must be understood by co-designers, is the first step that allows more fruitful discussion and immediate adjustment towards a quick embodiment of valid proposals. The paper describes how such techniques has been introduced in the mechanical engineering curriculum. The case of study reports the experience of the Brainwriting online, which has been tested during lockdown due to the pandemic disease of COVID-19. Further in the paper it is suggested a new interpretation of the de Saussure general linguistic studies, in term of a communication that is associated to a drawing

T.O.F. LASER SCANNER FOR THE SURVEYING OF STATUES: A TEST ON A REAL CASE

Abstract. The contribution regards the surveying of two statues of famous contemporary sculptors that have been placed in the central zone of Cosenza, which has been transformed in an open air museum. To realize a 3-D representation of the museum, different methodologies have been used, based on classical surveying (total stations and GNSS), image data and range data. The increasing performances of the new models of Time Of Flight (T.O.F.) laser scanners allow to build accurate models also for medium-size objects; on the other hand, the recent techniques of 3D modeling enable the processing of large amount of data and the effective removal of noises. Thus, if an extreme accuracy is not required, one can think to use the T.O.F. laser scanner, also for the surveying of statues. For the acquisition of the surfaces of the statues, two different types of laser scanning have been used: the Leica Scan StationC10, based on Time Of Flight, and the Minolta VIVID 300 triangulation scanner. In the paper, the comparison between the results obtained by using the different techniques is described

Adeguatezza della linfoadenectomia nel trattamento chirurgico del carcinoma del colon destro: analisi comparativa tra procedure laparotomiche e laparoscopiche

Il numero di linfonodi analizzati dipende da molteplici fattori che possono essere suddivisi in modificabili (tecnica chirurgica, accuratezza dell’esame istologico, tipo di ospedale) e non modificabili (obesità, età, sesso, fattori associati al tumore). Il nostro è uno studio retrospettivo che si pone l’obiettivo di evidenziare quanto alcuni di questi fattori influenzino la linfoadenectomia nell’emicolectomia destra e, se tali fattori, possano essere utilizzati preventivamente nella scelta della tecnica chirurgica più appropriata per il trattamento dei pazienti affetti da carcinoma del colon destro. Esso nasce dalle seguenti considerazioni: il numero di linfonodi esaminati nel trattamento chirurgico del carcinoma colico, in pazienti privi di metastasi a distanza alla diagnosi, è il fattore predittivo più importante di sopravvivenza a lungo termine; un maggior numero di linfonodi esaminati e un minore lymph node ratio correlano con una maggiore sopravvivenza a 5 anni dei pazienti operati; i risultati degli studi di Baxter et al del 2005 e di Bilimoria et al del 2008 hanno evidenziato che meno del 40% dei pazienti operati per carcinoma del colon ricevono un’adeguata linfoadenectomia (considerando come limite minimo 12 linfonodi esaminati

Engaging in Product Development as Means to Understand the Basics of Design

AbstractTeaching product design is not a trivisal task. Considering the experience done along 20 years of teaching at master level class in mechanical engineering it is possible to take stock. The model followed is Project-Based Learning and this method can be licensed as the model that gives greater satisfaction to all attendees. Students give high score to the survey organized by university at the end of the course to assess didactic validity. Also, teachers have many stimuli when discussing with students the activities proposed. The course is based on the development of an industrial product that solves a problem, eventually posed by industry or emerged by customers. Based on the course schedule, the different phases of product development put in evidence the steps that require divergent thinking and those where it is necessary to employ convergent thinking. A case study allows explaining all the phases of product design

Current guidelines for the management of non-alcoholic fatty liver disease: A systematic review with comparative analysis

The current epidemic of non-alcoholic fatty liver disease (NAFLD) is reshaping the field of hepatology all around the world. The widespread diffusion of metabolic risk factors such as obesity, type2-diabetes mellitus, and dyslipidemia has led to a worldwide diffusion of NAFLD. In parallel to the increased availability of effective anti-viral agents, NAFLD is rapidly becoming the most common cause of chronic liver disease in Western Countries, and a similar trend is expected in Eastern Countries in the next years. This epidemic and its consequences have prompted experts from all over the word in identifying effective strategies for the diagnosis, management, and treatment of NAFLD. Different scientific societies from Europe, America, and Asia-Pacific regions have proposed guidelines based on the most recent evidence about NAFLD. These guidelines are consistent with the key elements in the management of NAFLD, but still, show significant difference about some critical points. We reviewed the current literature in English language to identify the most recent scientific guidelines about NAFLD with the aim to find and critically analyse the main differences. We distinguished guidelines from 5 different scientific societies whose reputation is worldwide recognised and who are representative of the clinical practice in different geographical regions. Differences were noted in: the definition of NAFLD, the opportunity of NAFLD screening in high-risk patients, the noninvasive test proposed for the diagnosis of NAFLD and the identification of NAFLD patients with advanced fibrosis, in the follow-up protocols and, finally, in the treatment strategy (especially in the proposed pharmacological management). These difference have been discussed in the light of the possible evolution of the scenario of NAFLD in the next years

Combination of antibodies directed against different ErbB3 surface epitopes prevents the establishment of resistance to BRAF/MEK inhibitors in melanoma

Patients with metastatic melanoma bearing V600 mutations in BRAF oncogene clinically benefit from the treatment with BRAF inhibitors alone or in combination with MEK inhibitors. However, a limitation to such treatment is the occurrence of resistance. Tackling the adaptive changes helping cells survive from drug treatment may offer new therapeutic opportunities. Very recently the ErbB3 receptor has been shown to act as a central node promoting survival of BRAF mutated melanoma. In this paper we first demonstrate that ErbB3/AKT hyperphosphorylation occurs in BRAF mutated melanoma cell lines following exposure to BRAF and/or MEK inhibitors. This strongly correlates with increased transcriptional activation of its ligand neuregulin. Anti-ErbB3 antibodies impair the establishment of de novo cell resistance to BRAF inhibition in vitro. In order to more potently ablate ErbB3 activity we used a combination of two anti-ErbB3 antibodies directed against distinct epitopes of its extracellular domain. These two antibodies in combo with BRAF/MEK inhibitors potently inhibit in vitro cell growth and tumor regrowth after drug withdrawal in an in vivo xenograft model. Importantly, residual tumor masses from mice treated by the antibodies and BRAF/ERK inhibitors combo are characterized almost exclusively by large necrotic areas with limited residual areas of tumor growth. Taken together, our findings support the concept that triple therapy directed against BRAF/MEK/ErbB3 may be able to provide durable control of BRAF mutated metastatic melanoma

Rituximab Plus Chemotherapy Provides No Clinical Benefit in a Peripheral T-Cell Lymphoma Not Otherwise Specified with Aberrant Expression of CD20 and CD79a: A Case Report and Review of the Literature

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is the most common entity of mature T-cell neoplasms. PTCL-NOS generally has an aggressive behavior and is often refractory to standard therapy. Only a few cases of PTCL with aberrant expression of B-cell antigens have been reported so far. This phenotypic aberrancy may lead to misdiagnosis as B-cell non-Hodgkin lymphomas and eventual inappropriate patient management, whereas in an accurately diagnosed PTCL, the presence of CD20 may appear as an appealing therapeutic target. In this setting, response to anti-CD20 monoclonal antibody in combination with chemotherapy has been poorly explored. We describe the case of a 59-year-old male diagnosed by a pathological and molecular approach as PTCL-NOS with aberrant co-expression of the B-cell antigens CD20 and CD79a, which proved non-responsive to the addition of rituximab to standard polychemotherapy. This case highlights that the presence of CD20 in PTCL may be misleading in the diagnosis and also act as a lure for the clinician to adopt a rituximab-based treatment, the effectiveness of which is undefined as the molecular mechanisms underlying B-cell marker expression in PTCL