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Search Results: 1 - 10 of 5739 matches for " Fabio Frassetto "
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Single-Grating Monochromators for Extreme-Ultraviolet Ultrashort Pulses
Luca Poletto,Fabio Frassetto
Applied Sciences , 2013, DOI: 10.3390/app3010001
Abstract: A single-grating monochromator can be used for the spectral selection of ultrashort pulses without altering in a significant way the pulse duration, provided that the number of illuminated grooves is equal to the resolution. Two configurations are compared: the classical-diffraction mount (CDM) and the off-plane mount (OPM). The advantages and drawbacks of both configurations are presented. The two geometries can be joined in a new and innovative design of a monochromator with two interchangeable diffracting stages both used at grazing incidence, one with the gratings in the CDM and the other in the OPM. The use of two stages gives great flexibility: the OPM stage is used for sub-50 fs time response and low spectral resolution and the CDM stage for 100-200 fs time response and high spectral resolution. The design overcomes the limits of the two single configurations, giving on the same instrument either ultrafast response with low spectral resolution or slower response with higher resolution.
Momentum-dependent snapshots of a melting charge density wave
Jesse C. Petersen,Stefan Kaiser,Nicky Dean,Alberto Simoncig,Haiyun Liu,Adrian L. Cavalieri,Cephise Cacho,I. C. Edmond Turcu,Emma Springate,Fabio Frassetto,Luca Poletto,Sarnjeet S. Dhesi,Helmuth Berger,Andrea Cavalleri
Physics , 2010, DOI: 10.1103/PhysRevLett.107.177402
Abstract: Charge density waves (CDWs) underpin the electronic properties of many complex materials. Near-equilibrium CDW order is linearly coupled to a periodic, atomic-structural distortion, and the dynamics is understood in terms of amplitude and phase modes. However, at the shortest timescales lattice and charge order may become de-coupled, highlighting the electronic nature of this many-body broken symmetry ground state. Using time and angle resolved photoemission spectroscopy with sub-30-fs XUV pulses, we have mapped the time- and momentum-dependent electronic structure in photo-stimulated 1T-TaS2, a prototypical two-dimensional charge density wave compound. We find that CDW order, observed as a splitting of the uppermost electronic bands at the Brillouin zone boundary, melts well before relaxation of the underlying structural distortion. Decoupled charge and lattice modulations challenge the view of Fermi Surface nesting as a driving force for charge density wave formation in 1T-TaS2.
Aspectos da leptina na anorexia nervosa: possíveis efeitos benéficos no tratamento da hiperatividade
Frassetto, Silvana Soriano;Bitencourt, Graziela Oliveira de;
Revista de Nutri??o , 2009, DOI: 10.1590/S1415-52732009000500014
Abstract: recent studies have demonstrated a direct relationship between leptin and the regulation of energy balance, and as a factor involved in eating disorders. acting on the central nervous system, leptin affects food intake, glucose metabolism, body weight, the production of sexual hormones, and physical activity. studies with humans and animals indicate that low leptin levels are related to symptoms of anorexia nervosa: low food intake, excessive loss of body weight, amenorrhea and hyperactivity. thus, the degree of hypoleptinemia is not only a strong indication of low reserves of adipose tissue, but also of a severe disorder, and leptin levels can be used to better evaluate the seriousness of the disease. research has aimed to study the use of leptin in the treatment of patients with an, and positive results have been obtained in the reduction of hyperactivity. it is possible that leptin treatment associated with medication and psychotherapy can be beneficial for extremely active anorexia nervosa patients, making them more susceptible to further treatment. adequate food intake, medication, psychotherapy, and a comfortable environment during leptin treatment should be ensured. thus, this article aims to describe leptin and aspects related to anorexia, and discuss how this information can be important in the clinical evaluation of patients with this eating disorder.
Tensile Structures of Cables Net, Guidelines to Design and Applications  [PDF]
Fabio Rizzo
Open Journal of Civil Engineering (OJCE) , 2016, DOI: 10.4236/ojce.2016.62023
Abstract: The structural engineering design of not conventional typologies imposes a complex path that begins evaluating procedures of a preliminary design and ends with complex procedures to validate the analysis response. Any guide lines to follow are often available. About complex shapes, in particular, any details are presented in the codes to evaluate wind action and so wind tunnel experiments are necessary to valuate this. The evaluation of wind tunnel data is a complex process that often needs new and specific subroutines programmed by researchers. The difficult increases when the objective is to study a not specific building but general aspects as for examples the dependence of a generic phenomenon by a geometric sample; in this case it is necessary to design and to program numerical subroutines before and then the wind tunnel experiments. Often, these subroutines are left detached and are non-generalizable process. Purpose of this paper is to describe a complete procedure to pre- and post-process wind tunnel data with the objective to design a not convectional structure as a tensile structure. In this particular case the research aim is a parametrization of the aerodynamic behavior of Hyperbolic Paraboloid roofs, shape used for cables net. The reason of the experiments is the absence in the international codes of the pressure coefficients for these geometries. The paper describes the numerical procedure evaluated to choose a sufficient representative geometric sample, the numerical procedure evaluated to design and to construct the wind tunnel models and FE models, the numerical procedure to evaluate and to use for FEM analyses of the wind tunnel data, the numerical procedure to calculate nonlinear structural analysis, and, finally some applications. All these numerical procedures use basic theory derived for example by the cable theory, the fluid mechanic, the nonlinear geometric analysis and other. However specific codes were necessary and were programmed to apply the theories on the specific case of study; the complete methodology followed is presented. The goal is to create a free open domain where the numerical procedures evaluated are merged, added, modified by researchers with the aim to obtain a common space of use for wind engineering of not conventional structure.
Leiomyosarcoma of Pulmonary Vein Presenting as Left Atrial Mass: An Outline of Management Principles
Philemon Gukop,Guido Frassetto,Georgios Karapanagiotidis,Venkatachalam Chandrasekaran
Case Reports in Cardiology , 2012, DOI: 10.1155/2012/396319
Abstract: Leiomyosarcoma of the pulmonary vein is rare and has poor prognosis. Its clinical features are nonspecific and mimic benign conditions. Early diagnosis is challenging. Most cases have been diagnosed only at autopsy or on postoperative histology specimens. Treatment is essentially palliative complete surgical excision. We outline the principles of management with the case of a 39-year-old man with leiomyosarcoma of the left pulmonary veins extending into the left atrium. Extensive investigation to achieve early diagnosis and determine extent of disease is essential. Frozen section guided adequate excision of all cardiac tumours and resection of involved lung tissue achieve local disease control. Adjuvant chemoradiotherapy has been shown to enhance survival.
Corre o de defeito ósseo femural em c es utilizando implante cortical homólogo conservado em mel
Amendola Gustavo Frassetto,Ilha Márcia,Berger Raquel,Stedile Rafael
Acta Cirurgica Brasileira , 2003,
Abstract: OBJETIVO: Avaliar a utiliza o de osso canino conservado em mel como implante em defeitos ósseos criados em fêmures de c es. MéTODOS: Doze caninos adultos foram submetidos a remo o de um segmento ósseo retangular compreendendo um ter o do diametro do osso por 2cm de comprimento da diáfise femural. Posteriormente foram inseridos dois pinos intramedulares e fixado um implante ósseo conservado de tamanho compatível com o defeito através de cerclagem com fio de a o. Os animais foram avaliados radiograficamente no dia da interven o cirúrgica e aos 30 e 60 dias. RESULTADOS: Após o final dos 60 dias foi possível verificar incorpora o do implante em oito animais enquanto que em quatro houve reabsor o do material implantado. CONCLUS O: O mel pode ser adequado como conservante de ossos.
Leiomyosarcoma of Pulmonary Vein Presenting as Left Atrial Mass: An Outline of Management Principles
Philemon Gukop,Guido Frassetto,Georgios Karapanagiotidis,Venkatachalam Chandrasekaran
Case Reports in Cardiology , 2012, DOI: 10.1155/2012/396319
Abstract: Leiomyosarcoma of the pulmonary vein is rare and has poor prognosis. Its clinical features are nonspecific and mimic benign conditions. Early diagnosis is challenging. Most cases have been diagnosed only at autopsy or on postoperative histology specimens. Treatment is essentially palliative complete surgical excision. We outline the principles of management with the case of a 39-year-old man with leiomyosarcoma of the left pulmonary veins extending into the left atrium. Extensive investigation to achieve early diagnosis and determine extent of disease is essential. Frozen section guided adequate excision of all cardiac tumours and resection of involved lung tissue achieve local disease control. Adjuvant chemoradiotherapy has been shown to enhance survival. 1. Case Report A 39-year-old gentleman presented with recurrent shortness of breath, episodes of desaturation, chest pain, and haemoptysis. He was treated for recurrent chest infection. Computerised tomography scan showed a well circumscribed 4?cm diameter mass within the left atrium with some abnormal tissue within the left sided pulmonary veins which showed interval increase in size (Figure 1). Figure 1: Computer tomogram showing left atrial mass extending into left pulmonary veins. There was a multifocal ground glass opacity, nodularity, and consolidative changes within the left upper lobe representing a combination of infection, haemorrhage, and infarction (Figure 2). Figure 2: Computer tomogram of chest showing left atrial mass extending into pulmonary vein with left upper lobe lung consolidation. Echocardiogram confirmed a large left atrial mass measuring 3.6 by 4.5?cm causing mitral valve obstruction and appears to originate from the left superior pulmonary vein (Figure 3). Figure 3: Transthoracic echocardiogram showing left atrial mass obstructing left ventricular outlet tract and originating from left superior pulmonary vein. Cardiac magnetic resonance imaging (MRI) showed a large ( HLA) mass in the left atrium that appears to arise from the left upper lobe pulmonary vein and is not attached to the atrial septum (Figure 4). Following gadolinium there was heterogeneous opacification of the mass with absent filling of the left pulmonary veins. Figure 4: Cardiac magnetic resonance scan (MRI) showing left atrial mass obstructing left ventricular outlet tract. Median sternotomy, aortic-bicaval cannulation, and standard cardiopulmonary bypass were performed for excision of the left atrial mass. Via a right interatrial grove incision a large pedunculated, fibrous, hard mass with smooth surface
Evaluating software-based fingerprint liveness detection using Convolutional Networks and Local Binary Patterns
Rodrigo Frassetto Nogueira,Roberto de Alencar Lotufo,Rubens Campos Machado
Computer Science , 2015, DOI: 10.1109/BIOMS.2014.6951531
Abstract: With the growing use of biometric authentication systems in the past years, spoof fingerprint detection has become increasingly important. In this work, we implement and evaluate two different feature extraction techniques for software-based fingerprint liveness detection: Convolutional Networks with random weights and Local Binary Patterns. Both techniques were used in conjunction with a Support Vector Machine (SVM) classifier. Dataset Augmentation was used to increase classifier's performance and a variety of preprocessing operations were tested, such as frequency filtering, contrast equalization, and region of interest filtering. The experiments were made on the datasets used in The Liveness Detection Competition of years 2009, 2011 and 2013, which comprise almost 50,000 real and fake fingerprints' images. Our best method achieves an overall rate of 95.2% of correctly classified samples - an improvement of 35% in test error when compared with the best previously published results.
All-Optical Cryptographic Device for Secure Communication  [PDF]
Fabio Garzia, Roberto Cusani
Communications and Network (CN) , 2010, DOI: 10.4236/cn.2010.24034
Abstract: An all-optical cryptographic device for secure communication, based on the properties of soliton beams, is presented. It can encode a given bit stream of optical pulses, changing their phase and their amplitude as a function of an encryption serial key that merge with the data stream, generating a ciphered stream. The greatest advantage of the device is real-time encrypting – data can be transmitted at the original speed without slowing down.
Comparison of 4 Multi-User Passive Network Topologies for 3 Different Quantum Key Distribution  [PDF]
Fabio Garzia, Roberto Cusani
Communications and Network (CN) , 2010, DOI: 10.4236/cn.2010.23025
Abstract: The purpose of this paper is to compare the performance of four passive optical network topologies in implementing multi-user quantum key distribution, using 3 protocols proposed by quantum cryptography (B92, EPR, and SSP). The considered networks are the passive-star network, the optical-ring network based on the Signac interferometer, the wavelength-routed network, and the wavelength-addressed bus network. The quantum bit-error rate and sifted key rate for each of these topologies are analysed to determine their suitability for providing quantum key distribution-service to networks of various sizes. The efficiency of the three considered protocols is also determined.
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