Loading stress distribution in posterior teeth restored by different core materials under fixed zirconia partial denture: A 3d-fea study

Purpose: To evaluate the effect of different substrate stiffness [sound dentin (SD), resin composite core (RC) or metal core (MC)] on the stress distribution of a zirconia posterior three-unit fixed partial denture (FPD). Methods: The abutment teeth (first molar and first premolar) were modeled, containing 1.5 mm of axial reduction, and converging axial walls. A static structural analysis was performed using a finite element method and the maximum principal stress criterion to analyze the fixed partial denture (FPD) and the cement layers of both abutment teeth. The materials were considered isotropic, linear, elastic, homogeneous and with bonded contacts. An axial load (300 N) was applied to the occlusal surface of the second premolar. Results: The region of the prosthetic connectors showed the highest tensile stress magnitude in the FPD structure depending on the substrate stiffness with different core materials. The highest stress peak was observed with the use of MC (116.4 MPa) compared to RC and SD. For the cement layer, RC showed the highest values in the molar abutment (14.7 MPa) and the highest values for the premolar abutment (14.4 MPa) compared to SD (14.1 and 13.4 MPa) and MC (13.8 and 13.3 MPa). Both metal core and resin composite core produced adequate stress concentration in the zirconia fixed partial denture during the load incidence. However, more flexible substrates, such as composite cores, can increase the tensile stress magnitude on the cement

Sustained kidney biochemical derangement in treated experimental diabetes : a clue to metabolic memory.

The occurrence of biochemical alterations that last for a long period of time in diabetic individuals even after adequate handling of glycemia is an intriguing phenomenon named metabolic memory. In this study, we show that a kidney pathway is gradually altered during the course of diabetes and remains persistently changed after late glycemic control in streptozotocin-induced diabetic rats. This pathway comprises an early decline of uric acid clearance and pAMPK expression followed by fumarate accumulation, increased TGF-? expression, reduced PGC-1? expression, and downregulation of methylation and hydroxymethylation of mitochondrial DNA. The sustained decrease of uric acid clearance in treated diabetes may support the prolonged kidney biochemical alterations observed after tight glycemic control, and this regulation is likely mediated by the sustained decrease of AMPK activity and the induction of inflammation. This manuscript proposes the first consideration of the possible role of hyperuricemia and the underlying biochemical changes as part of metabolic memory in diabetic nephropathy development after glycemic control

The ITA Space Center and Its Role in Space Education in Brazil

This paper presents the ITA Space Center and its mission in the formation of human resources and in the research and development of space products. In 2012 the first aerospace engineers were graduated at ITA, and since then many efforts have been done to improve the engineering education. The first effort was the development of AESP-14 CubeSat project, then the development and launch of ITASAT, a 6U CubeSat. These two projects showed that small satellites projects provide a good learning approach once students were deeply involved in the development process. These two projects opened the opportunity for the creation of the ITA Space Center (CEI -acronym for Centro Espacial ITA in Portuguese). Inside its facilities the ITA Space Center provides capabilities for the development of small space projects such as electronics, software engineering, mechanical design, and simulation with the aid of systems engineering and project management. By means of the graduate and undergraduate programs the ITA Space Center is providing education and integration with the industries and other partner organizations. In developing and delivering space products, and fostering higher education in space, the ITA Space Center is accomplishing of its proposed mission

The ITASAT – The Lessons Learned from the Mission Concept to the Operation

The ITASAT Project was initiated as an effort of the Brazilian Space Agency (AEB), the Technological Institute of Aeronautics (ITA) and the National Institute of Space Research (INPE) to train human resources to the Aerospace sector due to the lack of experience of the students in practical projects in the aerospace segment in Brazil. In this effort students were challenged to design, build and operate a satellite in a hands-on project. Along the project years several changes happened on the satellite configuration, going through a 100 kg satellite to a 6U CubeSat and this last configuration was designed, assembled and tested. In December ITASAT was launched and since its launch has been tracked and operated by the ground operation team. In this paper we will discuss the lessons learned during the project, since the decision to change the satellite size and re-thinking the scope of the project objectives, focusing on system engineering, Assembly Integration and Testing (AIT), Verification and Validation (V&V) and ground operations. The paper will present the challenges of the group of students in this hands-on project, the mistakes and hits along the project phases

Bi-allelic JAM2 Variants Lead to Early-Onset Recessive Primary Familial Brain Calcification.

Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis. We report four unrelated families presenting with initial learning difficulties and seizures and later psychiatric symptoms, cerebellar ataxia, extrapyramidal signs, and extensive calcifications on brain imaging. Through a combination of homozygosity mapping and exome sequencing, we mapped this phenotype to chromosome 21q21.3 and identified bi-allelic variants in JAM2. JAM2 encodes for the junctional-adhesion-molecule-2, a key tight-junction protein in blood-brain-barrier permeability. We show that JAM2 variants lead to reduction of JAM2 mRNA expression and absence of JAM2 protein in patient's fibroblasts, consistent with a loss-of-function mechanism. We show that the human phenotype is replicated in the jam2 complete knockout mouse (jam2 KO). Furthermore, neuropathology of jam2 KO mouse showed prominent vacuolation in the cerebral cortex, thalamus, and cerebellum and particularly widespread vacuolation in the midbrain with reactive astrogliosis and neuronal density reduction. The regions of the human brain affected on neuroimaging are similar to the affected brain areas in the myorg PFBC null mouse. Along with JAM3 and OCLN, JAM2 is the third tight-junction gene in which bi-allelic variants are associated with brain calcification, suggesting that defective cell-to-cell adhesion and dysfunction of the movement of solutes through the paracellular spaces in the neurovascular unit is a key mechanism in CNS calcification

Highlights from the Pierre Auger Observatory

The Pierre Auger Observatory is the world's largest cosmic ray observatory. Our current exposure reaches nearly 40,000 km$^2$ str and provides us with an unprecedented quality data set. The performance and stability of the detectors and their enhancements are described. Data analyses have led to a number of major breakthroughs. Among these we discuss the energy spectrum and the searches for large-scale anisotropies. We present analyses of our X$_{max}$ data and show how it can be interpreted in terms of mass composition. We also describe some new analyses that extract mass sensitive parameters from the 100% duty cycle SD data. A coherent interpretation of all these recent results opens new directions. The consequences regarding the cosmic ray composition and the properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray Conference, Rio de Janeiro 201

A search for point sources of EeV photons

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical Journa

Reconstruction of inclined air showers detected with the Pierre Auger Observatory

We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than $60^\circ$ detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.Comment: 27 pages, 19 figures, accepted for publication in Journal of Cosmology and Astroparticle Physics (JCAP

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Síndrome de Ehrlers-Danlos: Ehrlers-Danlos Syndrome

INTRODUÇÃO: A Síndrome de Ehlers-Danlos (SED) refere-se a distúrbios hereditários do tecido conjuntivo e da função do colágeno provocando como manifestações principais a hiperextensibilidade da pele, a hipermobilidade articular e a fragilidade de tecidos. De acordo com a Classificação Internacional de 2017, são reconhecidos 13 diferentes subtipos que caracterizam a sua extensa variabilidade clínica, por conseguinte, seu difícil diagnóstico. Embora apresente rara incidência, possui alta complexidade no tratamento multidisciplinar de suas complicações clínicas, o que motiva maior produção de literatura científica, ainda escassa, principalmente em território nacional. APRESENTAÇÃO DO CASO: M.M.V.R., 30 anos, sexo feminino, raça branca, G2P2, com história familiar positiva para hipermobilidade articular com queixa de dor crônica que piorou há cerca de 15 anos, associado a sintomas gastrointestinais, dermatológicos e vasculares. DISCUSSÃO: Realizou-se o diagnóstico de SED, com base na história clínica e no exame físico, utilizando-se os critérios de Beighton, a paciente foi encaminhada para acompanhamento multidisciplinar, com adesão ao tratamento observou-se melhora na qualidade de vida da paciente. CONCLUSÃO: É de se notar, portanto, que a SED é extremamente complexa desde o diagnóstico ao manejo, porém, este relato evidenciou que o diagnóstico precoce associado a um projeto terapêutico multidisciplinar pode trazer resultados impactantes