Análise da ruína das lâminas de corte do descascador de toros da CELTEJO

No âmbito do processo industrial da Celtejo, Empresa de Celulose do Tejo, S.A., foi identificada uma quebra no desempenho do descascador que opera no parque de madeiras da sua unidade industrial. Esta quebra de desempenho verificava-se devido à ocorrência de um desgaste excessivo das suas lâminas de corte, obrigando à sua substituição regular e prematura. Tais quebras de desempenho tinham como implicação direta um incremento dos custos associados à operação e à manutenção do equipamento, bem como aos materiais e recursos humanos associados a essas operações, assim como às perdas de produção daí resultantes. A administração da Celtejo lançou o repto ao IPCB, no sentido de analisar a origem do desgaste dos componentes do descascador, bem como apresentar eventuais propostas de soluções com vista a minimizar o seu desgaste precoce. O presente trabalho constitui um estudo preliminar do problema, tendo sido desenvolvido, com supervisão, pelos alunos Francisco Vicente Granada Reis Pio e Paulo Alexandre Costa dos Santos através do seu trabalho “Ensaio metalográfico e microdureza dos microconstituintes do aço Hardox 500”, submetido para avaliação no âmbito da Unidade Curricular de Caracterização Mecânica dos Materiais do 2.º ano curricular da licenciatura em Engenharia Industrial.info:eu-repo/semantics/publishedVersio

A simulation toolkit for electroluminescence assessment in rare event experiments

A good understanding of electroluminescence is a prerequisite when optimising double-phase noble gas detectors for Dark Matter searches and high-pressure xenon TPCs for neutrinoless double beta decay detection. A simulation toolkit for calculating the emission of light through electron impact on neon, argon, krypton and xenon has been developed using the Magboltz and Garfield programs. Calculated excitation and electroluminescence efficiencies, electroluminescence yield and associated statistical fluctuations are presented as a function of electric field. Good agreement with experiment and with Monte Carlo simulations has been obtained

The European Food Safety Authority scientific opinion on a risk profile related to production and consumption of insects as food and feed

The increased attention to the use of farmed insects as a novel protein source has raised the question of the safety of insects as human food and as animal feed. This was the background for the European Union (EU) Commission to mandate the European Food Safety Authority (EFSA) to conduct a review of the current knowledge about biological, chemical and environmental risks associated with production and consumption of insects. National authorities in some EU member states (Belgium, the Netherlands and France) have conducted national assessments (ANSES, 2015; FASFC, 2014; NVWA, 2014). However, in the EU, existing regulations constitute legal barriers for marketing insects for human consumption and as protein in animal feed for food producing animals

Trends in Mesenchymal Stem Cells\u27 Applications for Skeletal Muscle Repair and Regeneration

Skeletal muscle injuries are quite frequent in traumatic scenarios, such as war injuries or road- or work-related accidents. The skeletal muscle has good regenerative ability, but the extent or recurrence of muscle injury might impair complete structural and functional recovery. Severe tissue loss overwhelms skeletal muscle´s intrinsic regenerative capabilities and culminates in the development of noncontractile fibrous tissue scar. Conservative RICE -based and surgical treatments show limited efficacy in terms of improving these severe cases outcomes, pressing the need for new approaches on skeletal muscle’s therapy. Since the first suggestions of the potential of mesenchymal stem cells for regenerative medicine and tissue engineering, many applications have been explored for a variety of tissues and diseases, including the skeletal muscle, which is the focus of this literature review

Evaluation of the cardiovascular effects of vasicine, an alkaloid isolated from the leaves of Sida cordifolia L. (Malvaceae)

The cardiovascular effects of vasicine, an alkaloid isolated from the leaves of Sida cordifolia L., were evaluated in this work. In non-anaesthetized rats (n=6), vasicine (1, 2.5, 5 and 10 mg/kg; i.v., randomly) induced hypotension associated with an intense bradycardia. Both responses were completely abolished after atropine (2mg/Kg; i.v.) and attenuated after hexamethonium (20 mg/Kg; i.v.). In isolated rat mesenteric artery rings, vasicine (0.03, 0.1, 0.3, 1, 3, 10, 30, 100 and 300 μg/mL, cumulatively) induced concentration-dependent relaxation of phenylephrine-induced tone (IC50= 3.8±0.9 μg/mL; n = 6). In conclusion, the results show that vasicine produce hypotension and bradycardia which appears to be due to the stimulation of cardiac muscarinic receptors (directly and/or indirectly), and by a decrease of the peripheral resistances

Population Structure Of Jatropha And Its Implication For The Breeding Program

Jatropha (Jatropha curcas L.) has potential as an oilseed crop that requires the development of technology for its exploitation. The objective of this study was to assess the population structure and the genetic diversity in jatropha accessions at a global level using simple sequence repeat (SSR) molecular markers. Jatropha accessions (N = 109) from 10 countries were genotyped using 10 SSR markers. The results showed a low level of genetic diversity among 92 accessions originating from India, Mozambique, Ethiopia, Tanzania, Brazil, Honduras, and Indonesia, which were grouped in one cluster. In contrast, accessions from Mexico and Costa Rica showed high level of genetic variability. These accessions may be used to increase the genetic diversity of jatropha in the breeding populations. The study also showed the need of collecting activity from the center of diversity (Mexico and Costa Rica) to aggregate the genetic diversity in the international collections of jatropha. © FUNPEC-RP.15

Reactivation of wild-type and mutant p53 by tryptophanolderived oxazoloisoindolinone SLMP53-1:a novel anticancer small-molecule

Restoration of the p53 pathway, namely by reactivation of mutant (mut) p53, represents a valuable anticancer strategy. Herein, we report the identification of the enantiopure tryptophanol-derived oxazoloisoindolinone SLMP53-1 as a novel reactivator of wild-type (wt) and mut p53, using a yeast-based screening strategy. SLMP53-1 has a p53-dependent anti-proliferative activity in human wt and mut p53R280K-expressing tumor cells. Additionally, SLMP53-1 enhances p53 transcriptional activity and restores wt-like DNA binding ability to mut p53R280K. In wt/mut p53-expressing tumor cells, SLMP53-1 triggers p53 transcription-dependent and mitochondrial apoptotic pathways involving BAX, and wt/mut p53 mitochondrial translocation. SLMP53-1 inhibits the migration of wt/mut p53-expressing tumor cells, and it shows promising p53-dependent synergistic effects with conventional chemotherapeutics. In xenograft mice models, SLMP53-1 inhibits the growth of wt/mut p53-expressing tumors, but not of p53-null tumors, without apparent toxicity. Collectively, besides the potential use of SLMP53-1 as anticancer drug, the tryptophanol-derived oxazoloisoindolinone scaffold represents a promissing starting point for the development of effective p53-reactivating drugs

Real world preventative drug management of migraine among Spanish neurologists

BACKGROUND: Many different preventatives have showed efficacy in the treatment of migraine. National guidelines differ in their recommendations and patients' characteristics are usually taken into account in their selection. In Spain, real life use of preventive therapies seems to be heterogeneous. We aimed to evaluate differences in clinical practice and adherence to national guidelines among Spanish neurologists. METHODS: Observational descriptive study. A survey was conducted among neurologists ascribed to the Spanish Society of Neurology. Participants were differentiated in accordance with their dedication to headache disorders. We analysed socio-demographic parameters and evaluated 43 questions considering migraine management as well as therapeutic choices regarding migraine sub-types and finally, neurologists' personal perception. RESULTS: One hundred fifty-five neurologists participated from 17 different regions, 43.4% of them female and 53.3% under 40¿years of age. 34.9% confirmed headache disorders as their main interest. The first choice for preventive therapy in chronic migraine among participants was topiramate (57%) followed by amytriptiline (17.9%) and beta-blockers (14.6%). However in episodic migraine, the preferred options were beta-blockers (47.7%), topiramate (21.5%) and amytriptiline (13.4%). Regarding perceived efficacy, topiramate was considered the best option in chronic migraine (42.7%) followed by onabotulinumtoxinA (25.5%) and amitryptiline (22.4%). Where episodic migraine was concerned, surveyed neurologists perceived topiramate (43.7%) and beta-blockers (30.3%) as the best options. When we evaluated the duration of treatment use with a view to adequate therapeutic response, 43.5% of neurologists preferred 3¿months duration and 39.5% were in favour of 6¿months duration in episodic migraine. However, considering the preferred duration of treatment use in chronic migraine, 20.4% recommended 3¿months, 42.1% preferred 6¿months and 12.5% and 22.4% opted for 9 and 12¿months respectively. When considering onabotulinumtoxinA therapy, the number of prior therapeutic failures was zero in 7.2% of neurologists, one in 5.9%, two in 44.1%, three in 30.9% and four or more in 11.9%. Following an initial treatment failure with onabotulinumtoxinA, 49% of subjects decided against a second treatment. The number of OnabotA procedures before considering it as ineffective was two in 18.9% of neurologists, three in 70.8% and four in 10.4%. CONCLUSIONS: The initial management of migraine among Spanish Neurologists is in line with most guidelines, where first choice preventative drugs are concerned. The Management of episodic migraine differed from chronic migraine, both in terms of neurologist preference and in their perceived efficacy

Impact of content and length of curauá fibers on mechanical behavior of extruded cementitious composites: Analysis of variance

[EN] The use of composite materials in construction has grown considerably in recent years, such as cementitious matrices and concrete reinforced with fibers. The vegetable fibers have become an alternative due to its abundance, low cost and low energy consumption for its production, and appropriate properties mechanical. Curauá fiber is a plant native from Amazonas harvested manually in commercial farming and it is used in the manufacture of ropes and baskets or as reinforcement in composite with organic matrix of components for cars, buses and trucks. On the other hand, the extrusion process can produce composites with high-density matrix with fibers, low permeability and good interface between fiber and matrix. This process is also compatible with the use of vegetable fibers as raw materials in the production of cost-effective construction elements such as ceiling panels and drywalls. The objective of this research was use the analysis of variance (ANOVA) for evaluating with rigor mathematical the influence of content and length of curauá fibers on the mechanical behavior of the extruded cementitious composites. Composites without fibers and reinforced with 1% and 2% by mass of fibers as well as 6 mm and 10 mm of length these curauá fibers were evaluated. The composites with fibers of 10 mm have showed better mechanical results. Besides, the composites with fibers curauá after 200 accelerated aging cycles were better than one non-aging.The authors acknowledge the financial support provided by Brazilian Agencies: Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Grant nº 2013/03823-8 and 2012/51467-3); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Grant nº 3886/2014); and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Grant nº 406429/2015 and 312151/2016-0). The authors thank the Brazilian companies Fibria S.A., Infibra S.A. and Imbralit Ltda. for technical support to the development of this work.Teixeria, R.; Santos, S.; Christoforo, A.; Paya Bernabeu, JJ.; Savastano Jr., H.; Rocco Lhar, F. (2019). Impact of content and length of curauá fibers on mechanical behavior of extruded cementitious composites: Analysis of variance. Cement and Concrete Composites. 102:134-144. https://doi.org/10.1016/j.cemconcomp.2019.04.022S13414410