СОРБЦИОННОЕ ИЗВЛЕЧЕНИЕ РЕНИЯ ИЗ ХРОМСОДЕРЖАЩИХ СУЛЬФАТНЫХ РАСТВОРОВ НИЗКООСНОВНЫМИ АНИОНИТАМИ СYBBER

Low-basic Cybber anionites with various functional groups and matrix type are tested for recovery of rhenium from multicomponent sulfuric acid solutions. It is established that anionite SX002 manifests an increased capacity during the sorption from solutions with a low Re content, while anionite ALX220 is applicable to recover Re at its high concentrations in the solution. The ionic background of the industrial solution affects the capacity of sorbents with respect to rhenium. When studying the kinetic characteristics, it is revealed that sorption processes on ionites are limited by the internal diffusion. The tests of ionites as applied to Cr-containing solutions indicate the possibility of using anionites ALX220 and SX002 to recover rhenium.Для извлечения рения из многокомпонентных серно-кислотных растворов опробованы образцы низкоосновных анионитов Cybber с различными функциональными группами и типом матрицы. Установлено, что анионит SX002 проявляет повышенную емкость при сорбции из растворов с низким содержанием Re, а ALX220 применим для извлечения Re при его высоких концентрациях в растворе. Ионный фон технологического раствора оказывает влияние на емкость сорбентов по рению. При изучении кинетических характеристик выявлено, что процессы сорбции на ионитах лимитируются внутренней диффузией. Проверка ионитов на технологических Cr-содержащих растворах свидетельствует о возможности применения анионитов ALX220 и SX002 для извлечения рения

Dianthracenylazatrioxa[8]circulene: synthesis, characterization and application in OLEDs

A soluble, green-blue fluorescent, pi-extended azatrioxa[8]circulene was synthesized by oxidative condensation of a 3,6-dihydroxycarbazole and 1,4-anthraquinone by using benzofuran scaffolding. This is the first circulene to incorporate anthracene within its carbon framework. Solvent-dependent fluorescence and bright green electroluminescence accompanied by excimer emission are the key optical properties of this material. The presence of sliding pi-stacked columns in the single crystal of dianthracenylazatrioxa[8]circulene is found to cause a very high electron-hopping rate, thus making this material a promising n-type organic semiconductor with an electron mobility predicted to be around 2.26 cm(2) V-1 s(-1). The best organic light-emitting diode (OLED) device based on the dianthracenylazatrioxa[8]circulene fluorescent emitter has a brightness of around 16 000 Cd m(-2) and an external quantum efficiency of 3.3 %. Quantum dot-based OLEDs were fabricated by using dianthracenylazatrioxa[8]circulene as a host matrix material.Peer reviewe

Canonical wnt signaling activity in early stages of chick lung development

Wnt signaling pathway is an essential player during vertebrate embryonic development which has been associated with several developmental processes such as gastrulation, body axis formation and morphogenesis of numerous organs, namely the lung. Wnt proteins act through specific transmembrane receptors, which activate intracellular pathways that regulate cellular processes such as cell proliferation, differentiation and death. Morphogenesis of the fetal lung depends on epithelial-mesenchymal interactions that are governed by several growth and transcription factors that regulate cell proliferation, fate, migration and differentiation. This process is controlled by different signaling pathways such as FGF, Shh and Wnt among others. Wnt signaling is recognized as a key molecular player in mammalian pulmonary development but little is known about its function in avian lung development. The present work characterizes, for the first time, the expression pattern of several Wnt signaling members, such as wnt-1, wnt-2b, wnt-3a, wnt-5a, wnt-7b, wnt-8b, wnt-9a, lrp5, lrp6, sfrp1, dkk1, β-catenin and axin2 at early stages of chick lung development. In general, their expression is similar to their mammalian counterparts. By assessing protein expression levels of active/total β-catenin and phospho-LRP6/LRP6 it is revealed that canonical Wnt signaling is active in this embryonic tissue. In vitro inhibition studies were performed in order to evaluate the function of Wnt signaling pathway in lung branching. Lung explants treated with canonical Wnt signaling inhibitors (FH535 and PK115-584) presented an impairment of secondary branch formation after 48 h of culture along with a decrease in axin2 expression levels. Branching analysis confirmed this inhibition. Wnt-FGF crosstalk assessment revealed that this interaction is preserved in the chick lung. This study demonstrates that Wnt signaling is crucial for precise chick lung branching and further supports the avian lung as a good model for branching studies since it recapitulates early mammalian pulmonary development.Rute S. Moura was supported by a grant of ON.2 SR&TD Integrated Program (N-01-01-0124-01-07), ref: UMINHO/BPD/31/2013. The funders had no role in study design, data collection and analysis

Stability of Yellow Fever Virus under Recombinatory Pressure as Compared with Chikungunya Virus

Recombination is a mechanism whereby positive sense single stranded RNA viruses exchange segments of genetic information. Recent phylogenetic analyses of naturally occurring recombinant flaviviruses have raised concerns regarding the potential for the emergence of virulent recombinants either post-vaccination or following co-infection with two distinct wild-type viruses. To characterize the conditions and sequences that favor RNA arthropod-borne virus recombination we constructed yellow fever virus (YFV) 17D recombinant crosses containing complementary deletions in the envelope protein coding sequence. These constructs were designed to strongly favor recombination, and the detection conditions were optimized to achieve high sensitivity recovery of putative recombinants. Full length recombinant YFV 17D virus was never detected under any of the experimental conditions examined, despite achieving estimated YFV replicon co-infection levels of ∼2.4×106 in BHK-21 (vertebrate) cells and ∼1.05×105 in C710 (arthropod) cells. Additionally YFV 17D superinfection resistance was observed in vertebrate and arthropod cells harboring a primary infection with wild-type YFV Asibi strain. Furthermore recombination potential was also evaluated using similarly designed chikungunya virus (CHIKV) replicons towards validation of this strategy for recombination detection. Non-homologus recombination was observed for CHIKV within the structural gene coding sequence resulting in an in-frame duplication of capsid and E3 gene. Based on these data, it is concluded that even in the unlikely event of a high level acute co-infection of two distinct YFV genomes in an arthropod or vertebrate host, the generation of viable flavivirus recombinants is extremely unlikely

Detection and elimination of cellular bottlenecks in protein-producing yeasts

Yeasts are efficient cell factories and are commonly used for the production of recombinant proteins for biopharmaceutical and industrial purposes. For such products high levels of correctly folded proteins are needed, which sometimes requires improvement and engineering of the expression system. The article summarizes major breakthroughs that led to the efficient use of yeasts as production platforms and reviews bottlenecks occurring during protein production. Special focus is given to the metabolic impact of protein production. Furthermore, strategies that were shown to enhance secretion of recombinant proteins in different yeast species are presented

On Strategic Orientation of Student Educational Activity

The article deals with the research in the field of the strategic orientation of educational activities in higher education. The necessity of applying a student-centered approach in such studies is revealed. It is noted that the factors influencing the strategic orientation of the student educational activity relate either to the space of ‘due’ or to the space of ‘being’. The invariant core of the graduate competence model belongs to the target-oriented space of the ‘due’. It includes 12 clusters of competencies and describes the normative context of the strategic orientation of the student educational activity. The personal context of this orientation is formed on the basis of a va riety of students’ goals in the space of ‘being’. It is characterized by student’s ideas about the relative importance of the qualities that one will need in future after graduation. The technique of establishing a hierarchy of combined graduate qualities is described. This hierarchy is determined by the student’s goals, which can be reflected through the subjective significance of the considered qualities for one. The analysis of results showed that the gender of the student and the character of his future labour activity significantly influence one’s strategic orientation