Algorithm for the determination of a linear crack in an elastic body from boundary measurements

Beretta, Elena,Francini, Elisa,Kim, Eunjoo,Lee, June-Yub Institute of Physics 2010 Inverse problems Vol.26 No.8

<P>In this paper we consider the inverse problem of identifying a linear inclusion inside an elastic body from exterior boundary measurements. Based on the asymptotic formula by Beretta and Francini (2006 <I>SIAM J. Math. Anal.</I> <B>38</B> 1249–61), we design an effective reconstruction algorithm to find the endpoints and the thickness of a linear inclusion. Numerical experiments show that the algorithm is effective and stable.</P>

ALGORITHM FOR THE DETERMINATION OF A LINEAR CRACK IN AN ELASTIC BODY FROM BOUNDARY MEASUREMENTS

Elena BERETTA,Elisa FRANCINI,Eun Joo KIM,June Yub LEE 한국산업응용수학회 2010 한국산업응용수학회 학술대회 논문집 Vol.5 No.1

In this paper we consider the inverse problem of identifying a linear inclusion inside an elastic body from exterior boundary measurements. Based on the asymptotic formula by Beretta et al. [7], we design an effective reconstruction algorithm to find two end-points and thickness of a linear inclusion. Numerical experiments shows that the algorithm is effective and stable.

Accuracy of computer-aided template-guided oral implant placement: a prospective clinical study

Beretta, Mario,Poli, Pier Paolo,Maiorana, Carlo Korean Academy of Periodontology 2014 Journal of Periodontal & Implant Science Vol.44 No.4

Purpose: The aim of the present study was to evaluate the in vivo accuracy of flapless, computer-aided implant placement by comparing the three-dimensional (3D) position of planned and placed implants through an analysis of linear and angular deviations. Methods: Implant position was virtually planned using 3D planning software based on the functional and aesthetic requirements of the final restorations. Computer-aided design/computer-assisted manufacture technology was used to transfer the virtual plan to the surgical environment. The 3D position of the planned and placed implants, in terms of the linear deviations of the implant head and apex and the angular deviations of the implant axis, was compared by overlapping the pre- and postoperative computed tomography scans using dedicated software. Results: The comparison of 14 implants showed a mean linear deviation of the implant head of 0.56 mm (standard deviation [SD], 0.23), a mean linear deviation of the implant apex of 0.64 mm (SD, 0.29), and a mean angular deviation of the long axis of $2.42^{\circ}$ (SD, 1.02). Conclusions: In the present study, computer-aided flapless implant surgery seemed to provide several advantages to the clinicians as compared to the standard procedure; however, linear and angular deviations are to be expected. Therefore, accurate presurgical planning taking into account anatomical limitations and prosthetic demands is mandatory to ensure a predictable treatment, without incurring possible intra- and postoperative complications.

Accuracy of computer-aided template-guided oral implant placement: a prospective clinical study

Mario Beretta,Pier Paolo Poli,Carlo Maiorana 대한치주과학회 2014 Journal of Periodontal & Implant Science Vol.44 No.4

Purpose: The aim of the present study was to evaluate the in vivo accuracy of flapless, computer-aided implant placement by comparing the three-dimensional (3D) position of planned and placed implants through an analysis of linear and angular deviations. Methods: Implant position was virtually planned using 3D planning software based on the functional and aesthetic requirements of the final restorations. Computer-aided design/computer-assisted manufacture technology was used to transfer the virtual plan to the surgical environment. The 3D position of the planned and placed implants, in terms of the linear deviations of the implant head and apex and the angular deviations of the implant axis, was compared by overlapping the pre- and postoperative computed tomography scans using dedicated software. Results: The comparison of 14 implants showed a mean linear deviation of the implant head of 0.56 mm (standard deviation [SD], 0.23), a mean linear deviation of the implant apex of 0.64 mm (SD, 0.29), and a mean angular deviation of the long axis of 2.42° (SD, 1.02). Conclusions: In the present study, computer-aided flapless implant surgery seemed to provide several advantages to the clinicians as compared to the standard procedure; however, linear and angular deviations are to be expected. Therefore, accurate presurgical planning taking into account anatomical limitations and prosthetic demands is mandatory to ensure a predictable treatment, without incurring possible intra- and postoperative complications.

A Case of Anti-N-Methyl-D-Aspartate Receptor Encephalitis Associated with Glioma of the Pons

Francesca Beretta,Angelo Aliprandi,Claudio Di Leo,Andrea Salmaggi 대한신경과학회 2019 Journal of Clinical Neurology Vol.15 No.1

Risk indicators related to periimplant disease: an observational retrospective cohort study

Poli, Pier Paolo,Beretta, Mario,Grossi, Giovanni Battista,Maiorana, Carlo Korean Academy of Periodontology 2016 Journal of Periodontal & Implant Science Vol.46 No.4

Purpose: The aim of the present study was to retrospectively investigate the influence of potential risk indicators on the development of peri-implant disease. Methods: Overall, 103 patients referred for implant treatment from 2000 to 2012 were randomly enrolled. The study sample consisted of 421 conventional-length (>6 mm) non-turned titanium implants that were evaluated clinically and radiographically according to preestablished clinical and patient-related parameters by a single investigator. A non-parametric Mann-Whitney U test or Kruskal-Wallis rank test and a logistic regression model were used for the statistical analysis of the recorded data at the implant level. Results: The diagnosis of peri-implant mucositis and peri-implantitis was made for 173 (41.1%) and 19 (4.5%) implants, respectively. Age (${\geq}65$ years), patient adherence (professional hygiene recalls <2/year) and the presence of plaque were associated with higher peri-implant probing-depth values and bleeding-on-probing scores. The logistic regression analysis indicated that age (P=0.001), patient adherence (P=0.03), the absence of keratinized tissue (P=0.03), implants placed in pristine bone (P=0.04), and the presence of peri-implant soft-tissue recession (P=0.000) were strongly associated with the event of peri-implantitis. Conclusions: Within the limitations of this study, patients aged ${\geq}65$ years and non-adherent subjects were more prone to develop peri-implant disease. Therefore, early diagnosis and a systematic maintenance-care program are essential for maintaining peri-implant tissue health, especially in older patients.

Risk indicators related to periimplant disease: an observational retrospective cohort study

Pier Paolo Poli,Mario Beretta,Giovanni Battista Grossi,Carlo Maiorana 대한치주과학회 2016 Journal of Periodontal & Implant Science Vol.46 No.4

Purpose: The aim of the present study was to retrospectively investigate the influence of potential risk indicators on the development of peri-implant disease. Methods: Overall, 103 patients referred for implant treatment from 2000 to 2012 were randomly enrolled. The study sample consisted of 421 conventional-length (>6 mm) nonturned titanium implants that were evaluated clinically and radiographically according to preestablished clinical and patient-related parameters by a single investigator. A non-parametric Mann-Whitney U test or Kruskal-Wallis rank test and a logistic regression model were used for the statistical analysis of the recorded data at the implant level. Results: The diagnosis of peri-implant mucositis and peri-implantitis was made for 173 (41.1%) and 19 (4.5%) implants, respectively. Age (≥65 years), patient adherence (professional hygiene recalls <2/year) and the presence of plaque were associated with higher peri-implant probing-depth values and bleeding-on-probing scores. The logistic regression analysis indicated that age (P=0.001), patient adherence (P=0.03), the absence of keratinized tissue (P=0.03), implants placed in pristine bone (P=0.04), and the presence of peri-implant soft-tissue recession (P=0.000) were strongly associated with the event of peri-implantitis. Conclusions: Within the limitations of this study, patients aged ≥65 years and non-adherent subjects were more prone to develop peri-implant disease. Therefore, early diagnosis and a systematic maintenance-care program are essential for maintaining peri-implant tissue health, especially in older patients.

OPTIMIZATION ALGORITHM FOR RECONSTRUCTING INTERFACE CHANGES OF A CONDUCTIVITY INCLUSION FROM MODAL MEASUREMENTS

H. Ammari,E. Beretta,E. Francini,H. Kang,Mikyoung Lim 한국산업응용수학회 2009 한국산업응용수학회 학술대회 논문집 Vol.2009 No.5

We propose an original optimization approach for reconstructing interface changes of a conductivity inclusion from measurements of eigenvalues and eigenvectors associated with the transmission problem for the Laplacian. Let Ω be a smooth domain and D be an inclusion contained in Ω whose boundary is also assumed to be smooth. Shape deformation of D causes a perturbation of modal parameters. The aim of this work is to show how this information can be used to reconstruct the unknown deformation. For doing so, we rigorously derive an asymptotic formula for the perturbations in the eigenvalues of the transmission problem for the Laplacian that are due to small deformations of the interface of an inclusion. Based on this formula, we design an efficient reconstruction algorithm from modal measurements. Our algorithm consists on minimizing a functional whose minimizer yields certain geometric properties of the unknown inclusion. It naturally follows from a key identity that is in some sense dual to the asymptotic formula. Numerical experiments showing the viability of our algorithm are presented. Our results in this paper extend those established in the context of small volume inclusions as well as those for the conductivity interface problem. In fact, on one hand, in a series of recent papers [5,3,1,2] we have derived high-order asymptotic expansions of the eigenvalue perturbations due to the presence of small inclusions and used them for locating the inclusions and identifying some of their geometric features. On the other hand, in [4], we have derived highorder terms in the asymptotic expansions of the boundary perturbations of steady-state voltage potentials resulting from small perturbations of the shape of a conductivity inclusion. Based on these derivations, we have designed an effective algorithm to determine some geometric features of the shape perturbation of the inclusion based on boundary measurements.

On the Preliminary Structural Design Strategy of the Wing of the Next-Generation Civil Tiltrotor Technology Demonstrator

Marika Belardo,Jacopo Beretta,Aniello Daniele Marano,Gianluca Diodati,Nicola Paletta,Luigi Di Palma 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.3

The T-WING project is a Clean Sky 2 research project aimed at designing, manufacturing, qualifying and flight-testing the new wing of the Next-Generation Civil Tiltrotor Technology Demonstrator (NGCTR-TD), as part of the Fast Rotorcraft Innovative Aircraft Demonstrator Platforms (FRC IADP) activities. Requirements, design strategy, methodology and main steps followed to achieve the composite wing preliminary design are presented. The main driving requirements have been expressed in terms of dynamic requirements (e.g., limitations on natural frequencies), aeroelastic requirements, i.e., compliance with European Aviation Safety Agency (EASA) CS-25 and CS-29 Airworthiness Requirements), structural requirements (e.g., target wing structural mass), functional requirements (e.g., fuel tanks, accessibility, assembly and integration, etc.) and wing preliminary loads. Based on the above-mentioned requirements, the first design loop is performed by targeting an optimal wing structure able to withstand preliminary design loads, and simultaneously with stiffness and inertia distributions leading to a configuration free from flutter within the flight envelope. The outcome from the first design loop is then used to refine the model and compute more reliable flight loads and repeat aeroelastic analysis, returning further requirements to be fulfilled in terms of wing stiffness and inertia distributions. The process is iterated till the fulfillment of all the project requirements.

Riluzole Selective Antioxidant Effects in Cell Models Expressing Amyotrophic Lateral Sclerosis Endophenotypes

Gessica Sala,Alessandro Arosio,Elisa Conti,Simone Beretta,Christian Lunetta,Nilo Riva,Carlo Ferrarese,Lucio Tremolizzo 대한정신약물학회 2019 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.17 No.3

Objective: Until recently, riluzole was the only drug licensed for amyotrophic lateral sclerosis (ALS). In spite of its efficacy, the mechanism of action remains elusive, and both blocking of glutamate release and antioxidant properties have been postulated. Here we characterized human SH-SY5Y neuroblastoma cell lines, taking advantage of their insensitivity to excitotoxic insults, in order to selectively assess the presence of a direct antioxidant effect of riluzole. Methods: SH-SY5Y cells, either parental or overexpressing the G93A SOD1 mutation, were exposed for 24 hours to the selected stimuli. Results: Riluzole (1‒10 M) was able to counteract the effects of H2O2 exposure (200 M/24 hr), limiting both cell death and whole-cell reactive oxygen species (ROS) increase. The same experiments were repeated using SH-SY5Y cells carrying the familial ALS-related G93A-SOD1 mutation and constitutively expressing two-fold increased whole-cell ROS levels with respect to wild-type cells: riluzole was ineffective in this paradigm. Analogously, riluzole was ineffective in preventing cell death induced by exposing SH-SY5Y cells to 3-morpholino-sydnonimine (SIN-1, 1.5 mM/24 hr), a reactive nitrogen species (RNS) donor. Conclusion: Our data support a direct antioxidant action of riluzole. Furthermore, the lack of efficacy of riluzole observed in the SOD1 cell model mirrors the lack of efficacy already demonstrated in cognate mouse models of ALS, plausibly reflecting differences in the underlying pathogenic mechanisms. Finally, riluzole inefficacy against nitrosative stress might support the idea that a combined therapeutic intervention may result more effective in ALS patients, as in the case of co-administration of edaravone, a drug known to reduce RNS.