Redesign of machine component in polymeric matrix composite towards increased productivity

This work is focused in the maximization of the acceleration a 2D Industrial Laser Cutting Machine (ILCM). The changes to be implemented are centered in the replacement of a metallic critical component: the gantry. This component largely influences precision and maximum acceleration. Finite Elements Analysis was performed to the current metallic part. From this analysis the maximum allowed deformations were established. A replacement composite component capable of an equally valid behavior was designed in carbon fiber. To establish the maximum increase in acceleration that does not lead to precision losses, the working conditions were simulated and the acceleration to which the component was subjected to was varied. The variation of the thickness of layers with different orientations and locations in the part allowed for the understanding of how the mass varies along with the maximum possible acceleration. This analysis, asides with considering the maximum force allowed by the linear motor that is responsible by the gantry motion, establishes the limit in terms of maximum acceleration of the machine. An increase of 22% in the maximum acceleration while maintaining the precision is possible due to the higher specific rigidity of composite materials and the use of an optimization heuristic

Redesign of an industrial laser cutting machine’s gantry in composite material

This work is focused in the design stage of a composite structure intended to replace a metallic critical component in a 2D Industrial Laser Cutting Machine (ILCM). The component is the gantry, largely responsible for most of the ILCM’s characteristics. These include precision and maximum acceleration, which are critical. The dimensioning of the component is initially performed based on analytical models, but latter stages use the numerical capabilities of Finite Elements Method. In the end it is possible to take advantage of the higher specific rigidity of composite materials to increase the maximum acceleration that the machine allows for while maintaining the precision.(undefined

Mechanical joining methods for additive manufactured assembly tools

The use of additive manufacturing (AM) processes is growing in the manufacturing industry. One application with great potential for using these processes is the manufacture of assembly tools for a high-ly competitive markets, such as the automotive industry. A critical aspect of the assembly tool design is its capability to incorporate modifications even at a late stage of its development in very short time. In many cases, these modifications are achieved using metal inserts in the polymeric tool, which allow to add new geometric features. This capability increases the usefulness and versatility of components produced by AM and compensate for potential shortcomings of using additive mate-rials. The purpose of this paper is to evaluate the potential use of accessories in additive manufactured com-ponents. In addition, the effect of different percentages of infill tool material on the joining quality of accesso-ries is evaluated. This is done by performing a screw pull-out test on a ABS ESD-7 part, produced by fused deposition modelling. The following different joining solutions were compared and studied in this work: em-bedded inserts, glue, heating processes, pressure (Tap-in) and creation of threads, such as, printing the thread directly and machining the thread onto the material.Programa Operacional Competitividade e Internacionalização - COMPETE 2020, Projeto nº 002814, Ref. POCI-01-0247-FEDER-002814 entre a Univ. do Minho e a Bosc

Presentation and validation of a new optical sensing concept based in a 3d-printing solution

In high competitive markets, such as the automotive industry, the better quality of products, reduction of manufacturing costs and the fulfilment of all delivery deadlines can only be achieved through continuous improvement of production capabilities. One current strategy is to develop and create smarter and adaptive assembly tools. Automation is a relevant area of development in the current industrial world and the baseline of the fourth industrial revolution (Industry 4.0). Namely, it is very important to use sensing components on jigs for assembly parts in the production line. The arrangement of sensing components on the assembly tools is very dependent of the product, making the project more complex and less flexible. This issue can penalise the productivity heavily, especially if a wide range of products and changeover operations are usual. The use of Additive Manufacturing (AM) is growing in the industry and offers a high potential for research and development in the present stage. The AM is advantageous in many areas, especially in the rapid construction of complex tools (RP). This paper presents a new optical sensing concept based on the 3D printing of internal circuits in the assembly tools. This solution can bring many advantages and increase tools flexibility.Programa Operacional de Competividade e Internacionalização - COMPETE 2020, Projeto nº 002814; Ref. POCI-01-0247-FEDER-002814, entre a Univ. Minho e a Bosc

Management of epithelial precancerous conditions and lesions in the stomach (MAPS II): European Society of Gastrointestinal Endoscopy (ESGE), European Helicobacter and Microbiota Study Group (EHMSG), European Society of Pathology (ESP), and Sociedade Portuguesa de Endoscopia Digestiva (SPED) guideline update 2019

Patients with chronic atrophic gastritis or intestinal metaplasia (IM) are at risk for gastric adenocarcinoma. This underscores the importance of diagnosis and risk stratification for these patients. High definition endoscopy with chromoendoscopy (CE) is better than high definition white-light endoscopy alone for this purpose. Virtual CE can guide biopsies for staging atrophic and metaplastic changes and can target neoplastic lesions. Biopsies should be taken from at least two topographic sites (antrum and corpus) and labelled in two separate vials. For patients with mild to moderate atrophy restricted to the antrum there is no evidence to recommend surveillance. In patients with IM at a single location but with a family history of gastric cancer, incomplete IM, or persistent Helicobacter pylori gastritis, endoscopic surveillance with CE and guided biopsies may be considered in 3 years. Patients with advanced stages of atrophic gastritis should be followed up with a high quality endoscopy every 3 years. In patients with dysplasia, in the absence of an endoscopically defined lesion, immediate high quality endoscopic reassessment with CE is recommended. Patients with an endoscopically visible lesion harboring low or high grade dysplasia or carcinoma should undergo staging and treatment. H. pylori eradication heals nonatrophic chronic gastritis, may lead to regression of atrophic gastritis, and reduces the risk of gastric cancer in patients with these conditions, and it is recommended. H. pylori eradication is also recommended for patients with neoplasia after endoscopic therapy. In intermediate to high risk regions, identification and surveillance of patients with precancerous gastric conditions is cost-effective.info:eu-repo/semantics/publishedVersio

The Dynamics of Nestedness Predicts the Evolution of Industrial Ecosystems

In economic systems, the mix of products that countries make or export has been shown to be a strong leading indicator of economic growth. Hence, methods to characterize and predict the structure of the network connecting countries to the products that they export are relevant for understanding the dynamics of economic development. Here we study the presence and absence of industries at the global and national levels and show that these networks are significantly nested. This means that the less filled rows and columns of these networks' adjacency matrices tend to be subsets of the fuller rows and columns. Moreover, we show that nestedness remains relatively stable as the matrices become more filled over time and that this occurs because of a bias for industries that deviate from the networks' nestedness to disappear, and a bias for the missing industries that reduce nestedness to appear. This makes the appearance and disappearance of individual industries in each location predictable. We interpret the high level of nestedness observed in these networks in the context of the neutral model of development introduced by Hidalgo and Hausmann (2009). We show that, for the observed fills, the model can reproduce the high level of nestedness observed in these networks only when we assume a high level of heterogeneity in the distribution of capabilities available in countries and required by products. In the context of the neutral model, this implies that the high level of nestedness observed in these economic networks emerges as a combination of both, the complementarity of inputs and heterogeneity in the number of capabilities available in countries and required by products. The stability of nestedness in industrial ecosystems, and the predictability implied by it, demonstrates the importance of the study of network properties in the evolution of economic networks.Comment: 26 page

Structural and spatially-resolved studies on the hardening of a commercial resin-modified glass-ionomer cement

A commercial photopolymerizable resinmodified glass-ionomer (Fuji II LC) was studied using a variety of nuclear magnetic resonance (NMR) techniques. H and F stray-field imaging (STRAFI) enabled to follow the acid–base reaction kinetics in self-cured (SC) samples. Gelation and maturation processes with 25 min and 40 h average time constants, respectively, were distinguished. In self- & photo-cured (SPC) samples, two processes were also observed, which occurred with 2 s and 47 s average time constants. H, Al and Si magic angle spinning (MAS) NMR, C cross-polarization (CP)/MAS NMR and 27Al multiple quanta (MQ)MAS NMR spectroscopy were used to obtain structural information on the glass and cements that were either SC or SPC. The presence of methacrylate groups was identified in the solid component. Unreacted hydroxyl ethylmethacrylate (HEMA) was detected in self-cured cement. Al data showed that approximately 28% and 20% of Al is leached out from glass particles in SC and SPC samples, respectively. The upfield shift detected in 25Si MAS NMR spectra of the cements is consistent with a decrease in the number of Al species in the second coordination sphere of the silicon structures. Scanning electron microscopy (SEM) showed existence of 3D shrinkage of the cement matrix in photo-cured cements.(undefined

Genome-wide signatures of complex introgression and adaptive evolution in the big cats.

The great cats of the genus Panthera comprise a recent radiation whose evolutionary history is poorly understood. Their rapid diversification poses challenges to resolving their phylogeny while offering opportunities to investigate the historical dynamics of adaptive divergence. We report the sequence, de novo assembly, and annotation of the jaguar (Panthera onca) genome, a novel genome sequence for the leopard (Panthera pardus), and comparative analyses encompassing all living Panthera species. Demographic reconstructions indicated that all of these species have experienced variable episodes of population decline during the Pleistocene, ultimately leading to small effective sizes in present-day genomes. We observed pervasive genealogical discordance across Panthera genomes, caused by both incomplete lineage sorting and complex patterns of historical interspecific hybridization. We identified multiple signatures of species-specific positive selection, affecting genes involved in craniofacial and limb development, protein metabolism, hypoxia, reproduction, pigmentation, and sensory perception. There was remarkable concordance in pathways enriched in genomic segments implicated in interspecies introgression and in positive selection, suggesting that these processes were connected. We tested this hypothesis by developing exome capture probes targeting ~19,000 Panthera genes and applying them to 30 wild-caught jaguars. We found at least two genes (DOCK3 and COL4A5, both related to optic nerve development) bearing significant signatures of interspecies introgression and within-species positive selection. These findings indicate that post-speciation admixture has contributed genetic material that facilitated the adaptive evolution of big cat lineages

Biochemical evaluation of a series of synthetic chalcone and hydrazide derivatives as novel inhibitors of cruzain from Trypanosoma cruzi

Chagas’ disease, a parasitic infection widely distributed throughout Latin America, is a major public health problem with devastating consequences in terms of human morbidity and mortality. The enzyme cruzain is the major cysteine protease from Trypanosoma cruzi, the etiologic agent of American trypanosomiasis or Chagas’ disease, and has been selected as an attractive target for the development of novel trypanocidal drugs. In the present work, we describe the synthesis and inhibitory effects of a series of thirty-three chalcone and seven hydrazide derivatives against the enzyme cruzain from T. cruzi. Most of the compounds showed promising in vitro inhibition (IC50 values in the range of 20-60 μM), which suggest the potential of these compounds as lead candidates for further development. Twelve compounds have not been reported before, and four of them (7, 13, 16 e 18) are among the most potent inhibitors of the series.A doença de Chagas, uma infecção parasitária amplamente distribuída na América Latina, é um problema grave de saúde pública com conseqüências devastadoras em termos de morbidade e mortalidade humana. A enzima cruzaína é a principal cisteíno protease do Trypanosoma cruzi, agente etiológico da tripanossomíase Americana ou doença de Chagas, e foi selecionada como alvo atrativo para o desenvolvimento de novos fármacos tripanocidas. No presente trabalho, a síntese e os efeitos inibitórios de uma série de trinta e três chalconas e sete hidrazidas são descritos contra a enzima cruzaína de T.cruzi. A maioria dos compostos mostraram inibição promissora in vitro (valores de IC50 na faixa de 20-60 μM), o que sugere o potencial desses compostos como candidatos a líderes para contínuo desenvolvimento. Doze compostos são inéditos, sendo que quatro destes (7, 13, 16 e 18) estão entre os inibidores mais potentes da série.CNPqFAPESPCAPE

Collagen-Based Films Containing Liposome-Loaded Usnic Acid as Dressing for Dermal Burn Healing

The aim of this study was assess the effect of collagen-based films containing usnic acid as a wound dressing for dermal burn healing. Second-degree burn wounds were performed in forty-five Wistar rats, assigned into nine groups: COL—animals treated with collagen-based films; PHO—animals treated with collagen films containing empty liposomes; UAL—animals treated with collagen-based films containing usnic acid incorporated into liposomes. After 7, 14, and 21 days the animals were euthanized. On 7th day there was a moderate infiltration of neutrophils, in UAL, distributed throughout the burn wounds, whereas in COL and PHO, the severity of the reaction was slighter and still limited to the margins of the burn wounds. On the 14th day, the inflammatory reaction was less intense in UAL, with remarkable plasma cells infiltration. On the 21st day, there was reduction of the inflammation, which was predominantly composed of plasma cells in all groups, particularly in UAL. The use of the usnic acid provided more rapid substitution of type-III for type-I collagen on the 14th day, and improved the collagenization density on the 21st day. It was concluded that the use of reconstituted bovine type-I collagen-based films containing usnic acid improved burn healing process in rats