Low-temperature Thermochemical Treatments of Stainless Steels – An Introduction

Plasma technology used to perform thermochemical treatments is well established for the majority of steels, but it is not the case for the different stainless steel classes. Thus, important scientific and technological achievements can be expected in the coming years regarding plasma-assisted thermochemical treatment of such steels. The metallurgical aspects as well as the application cost-efficiency of stainless steels impose specific requirements for the thermochemical treatment, such as easy native chromium-rich oxide layer removal and surface activation at low temperature, which do not appear for other steel classes (plain, low-alloy, and tool steels). Thus, due to the highly reactive physicochemical environment created by the plasma, plasma-assisted technology presents advantages over other “conventional” technologies like those performed in gas or liquid environments. Low temperature is needed to avoid the reduction of corrosion resistance of stainless steels, by suppressing chromium carbide/nitride precipitation, and, in this case, good surface properties are achieved by the formation of treated layers containing metastable phases. Such attributes make the low-temperature plasma thermochemical treatments of stainless steels an important R&D field in the domain of plasma technology and surface treatments, and the goal of this chapter is to introduce the reader to this important topic

Obtenção de austenita expandida (fase S): Nitretação por plasma em baixa temperatura x SHTPN – Parte 3

Corpos de prova de aço inoxidável austenítico ISO 5832-1(similar ao AISI 316L, para aplicaçõesbiomédicas) apresentando camada superficial enrriquecida em nitrogênio (fase S), obtidos pelos processos denitretação por plasma em baixa temperatura e SHTPN (Solution Heat Treatment after Plasma Nitriding -Tratamento de solubilização após nitretação por plasma), além de amostras não tratadas, foram testadas emensaio de desgaste microabrasivo do tipo esfera livre. Os resultados mostraram que as superfícies nitretadaspor plasma em baixa temperatura apresentam o menor coeficiente de desgaste para menores tempos deensaio. No entanto, devido à pequena espessura de camada nitretada, com o aumento do tempo de ensaio asamostras processadas via SHTPN passam a apresentar desempenho superior, indicando que, dependendo dassolicitações de desgaste, um ou outro processo apresenta o melhor desempenho.Palavras-chave: Nitretação por plasma, SHTPN, fase S, ISO 5832-1, desgaste microabrasivo

Amblyomma imitator Ticks as Vectors of Rickettsia rickettsii, Mexico

Real-time PCR of Amblyomma imitator tick egg masses obtained in Nuevo Leon State, Mexico, identified a Rickettsia species. Sequence analyses of 17-kD common antigen and outer membrane protein A and B gene fragments showed to it to be R. rickettsii, which suggested a potential new vector for this bacterium

Reference Genes for Accurate Transcript Normalization in Citrus Genotypes under Different Experimental Conditions

Real-time reverse transcription PCR (RT-qPCR) has emerged as an accurate and widely used technique for expression profiling of selected genes. However, obtaining reliable measurements depends on the selection of appropriate reference genes for gene expression normalization. The aim of this work was to assess the expression stability of 15 candidate genes to determine which set of reference genes is best suited for transcript normalization in citrus in different tissues and organs and leaves challenged with five pathogens (Alternaria alternata, Phytophthora parasitica, Xylella fastidiosa and Candidatus Liberibacter asiaticus). We tested traditional genes used for transcript normalization in citrus and orthologs of Arabidopsis thaliana genes described as superior reference genes based on transcriptome data. geNorm and NormFinder algorithms were used to find the best reference genes to normalize all samples and conditions tested. Additionally, each biotic stress was individually analyzed by geNorm. In general, FBOX (encoding a member of the F-box family) and GAPC2 (GAPDH) was the most stable candidate gene set assessed under the different conditions and subsets tested, while CYP (cyclophilin), TUB (tubulin) and CtP (cathepsin) were the least stably expressed genes found. Validation of the best suitable reference genes for normalizing the expression level of the WRKY70 transcription factor in leaves infected with Candidatus Liberibacter asiaticus showed that arbitrary use of reference genes without previous testing could lead to misinterpretation of data. Our results revealed FBOX, SAND (a SAND family protein), GAPC2 and UPL7 (ubiquitin protein ligase 7) to be superior reference genes, and we recommend their use in studies of gene expression in citrus species and relatives. This work constitutes the first systematic analysis for the selection of superior reference genes for transcript normalization in different citrus organs and under biotic stress

ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America

Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1–6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km 2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km 2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the The Authors. Ecology © 2018 The Ecological Society of Americ

Treatment of Glycine and Proline in Late Ar-O-2 Afterglow

International audienceGlycine and proline have been treated in Ar-O-2 afterglows at low temperature to study their modification in highly reactive non-equilibrium media. These two amino-acids can be efficiently etched in suited conditions. In the case of glycine, O(P-3) is the main reactive species responsible for the etching mechanism. It reacts preferentially with the -CH2- group instead of the amine group-NH2. Further oxidation processes are observed but they are not rate-limiting. Etching of proline is a multi-step process, probably initiated by O(P-3) and then followed by reactions which control the etch-rate, the opening of the non-aromatic ring of proline being a probable route

A RELEVÂNCIA DA BIOECONOMIA PARA O DESENVOLVIMENTO REGIONAL: ESTUDO DE CASO EM UMA EMPRESA DE BIOCOSMÉTICOS DO ESTADO DO AMAZONAS The relevance of bioeconomy to regional development: a case study in a biocosmetics company in Amazonas

A bioeconomia surgiu como alternativa para contribuir para o processo de desenvolvimento local e regional dos espaços nos quais se verifica a abundância de recursos naturais. Este segmento pode ajudar a atender às demandas decorrentes do aumento populacional, mudanças climáticas, saúde, substituição de energias fósseis, entre outros, tendo como seu foco principal a utilização de recursos provenientes de base biotecnológica. Em alguns contextos, contudo, a adoção da dessa atividade econômica ainda não foi incorporada de forma massiva. Este trabalho teve como objetivo geral abordar a bioeconomia e sua relevância para o Estado Amazonas. Para atingir este objetivo, realizou-se um estudo de caso sendo uma empresa no setor de biocosméticos o objeto de análise deste estudo. A partir da experiência descrita pela empresa, verificou-se que há espaço para o desenvolvimento da bioeconomia no Estado do Amazonas, entretanto, fornecimento das matérias primas amazônicas representam gargalos em termos de regularidade e de qualidade. Estes gargalos precisam ser enfrentados com políticas públicas. Por se tratar de empresa de base biotecnológica, observou-se a importância de parcerias entre startups e institutos de pesquisa

Influence of neutral and charged species on the plasma degradation of the stearic acid

In this work, stearic acid (SA) was degraded in an Ar-O2and Ar-H2post-discharge environment created by a plasma reactor with a microwave source and in an Ar, Ar-H2and Ar-O2DC (Direct Current) discharge environment created in a cathode-anode confined system. The afterglow region is useful for understanding the role of the chemically active species (O, O2, H and H2). In contrast, the discharge region allows the observation of the effects of chemically active species, charged species (ions and electrons) and photons. The influence of these species on the grafting and etching of SA was evaluated by measuring the mass variation, mass variation rate and chemical composition. The results showed that when only chemically active oxygen species are present, the SA is preferentially grafted. However, when both photons and charged species are present, the SA is more efficiently etched. When the Ar-H2and Ar environments are utilized; the SA is not efficiently degraded