66 research outputs found
COMIC COMMUNICATION MECHANISM AS AN INTENTIONAL-MOTIVATED CONTAMINATION
A communicative mechanism described as a comic-motivated intentional contamination that means a change as a result of cross-breeding different words or expressions of similar sounding, construction, and meaning. This mechanism is realized through the transfer of communicative intention, i.e. resulting motives and goals of the communication
MODELLING AS A KNOWLEDGE GAINING TECHNIQUE FOR PRIMARY SCHOOL STUDENTS WHO LEARN SOLVING COMPLEX TASKS
Abstract.Using an example of composite tasks and the teaching techniquebehind them, the authors describe how primary school students learn to use modelling as part of their knowledge gaining process in education. The use of modelling during math classes is one of the pre-conditions for successful learning with primary school children as with the help of modelling children can better imagine what the task implies and better understand the relationship between different values, which enhances their awareness when deciding on what operation to apply, and so on.The article describes different models and submodels used by teachers for taskmodelling. It is noted that when learning how to solve composite tasks, children learn to reflect and acquire the ability to act inside their minds and analyze their thinking.Keywords: Knowledge gaining, mathematics teaching, modelling, compositetask
Evaluation of biochemical indicators in blood plasma of rats with tetracycline-induced hepatosis and their correction by milk phospholipids
Tetracycline is a drug with direct cytotoxic action on the liver, and therefore it is widely used in pharmaceutical studies of therapeutic effectiveness of hepatoprotective preparations. The aim of the present work was to determine the biochemical indicators in blood plasma of rats with tetracycline-induced hepatosis and correction properties of milk phospholipids under tetracycline-induced hepatosis in rats. To achieve this, Wistar rats were administered 250 mg/kg of 4% tetracycline hydrochloride suspension once a day intragastrically. As the corrective therapy, 1% solution of BAS “FLP-MD” was administered in liposomal form based on milk phospholipids. Under modeled steatohepatitis, significant destructive changes were observed in the cell membranes of hepatocytes in experimental rats. It was confirmed by higher activity of transaminase (in particular, activity of АSТ increased 4 times, that of ALT 1.7 times and the AST/ALT ratio was increased 2.4 times in blood plasma). The synthesis of clotting factors in livers of animals with hepatosis was inhibited. The content of fibrinogen in blood plasma decreased by 21%, factor II (prothrombin) by 27.8%, Xa-factor by 27.9%, and protein C by 40.6%. The animals also had hypochromic anemia, azotemia and bilirubinemia. The calcium-phosphor metabolism and hyperkalemia were observed. The liposomal BAS “FLP-MD” based on milk phospholipids diminished harmful effects of tetracycline, in particular supporting blood coagulation factors’ level restoration, and also by the activity of transaminases. According to the results, it may be used in prophylactics and pharmaceutical correction of steatohepatitis
The role of macroelements in the pathogenesis of bronchial asthma in children
Objective: to study the role of macroelements in the pathogenesis of bronchial asthma in children. Materials and methods: A total of 131 patients with different degrees of bronchial asthma severity were examined instantaneously. The reference group consisted of 31 children of the respective gender and age groups 1 and 2A. The average age of children was 11.83 ± 3.38 years old. All children in the cohort were given a comprehensive clinical-laboratory examination, peakflowmetry, pulsoxymetry, and spirometry. The study of mineral homeostasis in blood serum was carried out by X-ray fluorescence analysis. Statistical processing of the results was performed using the Statistica 10 and Microsoft Office Excel 2010, calculations were carried out in the program R. Results: It was found that the levels of potassium, phosphorus, and sulfur in children with bronchial asthma were elevated, while the levels of calcium, magnesium, and chlorine were reduced compared to the control group patients. The content of these macronutrients in patients with varying degrees of disease severity did not have significant differences. Conclusions: The data obtained on the changes in macro-element homeostasis indicate the important role of diselementosis in the pathogenesis of BA. It is a significant factor that contributes to the progression of chronic inflammation in bronchial organs that requires correction of therapy in children
An efficient Foxtail mosaic virus vector system with reduced environmental risk
<p>Abstract</p> <p>Background</p> <p>Plant viral vectors offer high-yield expression of pharmaceutical and commercially important proteins with a minimum of cost and preparation time. The use of <it>Agrobacterium tumefaciens </it>has been introduced to deliver the viral vector as a transgene to each plant cell via a simple, nonsterile infiltration technique called "agroinoculation". With agroinoculation, a full length, systemically moving virus is no longer necessary for excellent protein yield, since the viral transgene is transcribed and replicates in every infiltrated cell. Viral genes may therefore be deleted to decrease the potential for accidental spread and persistence of the viral vector in the environment.</p> <p>Results</p> <p>In this study, both the coat protein (CP) and triple gene block (TGB) genetic segments were eliminated from <it>Foxtail mosaic virus </it>to create the "FECT" vector series, comprising a deletion of 29% of the genome. This viral vector is highly crippled and expresses little or no marker gene within the inoculated leaf. However, when co-agroinoculated with a silencing suppressor (p19 or HcPro), FECT expressed GFP at 40% total soluble protein in the tobacco host, <it>Nicotiana benthamiana</it>. The modified FoMV vector retained the full-length replicase ORF, the TGB1 subgenomic RNA leader sequence and either 0, 22 or 40 bases of TGB1 ORF (in vectors FECT0, FECT22 and FECT40, respectively). As well as <it>N. benthamiana</it>, infection of legumes was demonstrated. Despite many attempts, expression of GFP via syringe agroinoculation of various grass species was very low, reflecting the low <it>Agrobacterium</it>-mediated transformation rate of monocots.</p> <p>Conclusions</p> <p>The FECT/40 vector expresses foreign genes at a very high level, and yet has a greatly reduced biohazard potential. It can form no virions and can effectively replicate only in a plant with suppressed silencing.</p
Detection of Resistance Mutations to Antivirals Oseltamivir and Zanamivir in Avian Influenza A Viruses Isolated from Wild Birds
The neuraminidase (NA) inhibitors oseltamivir and zanamivir are the first-line of defense against potentially fatal variants of influenza A pandemic strains. However, if resistant virus strains start to arise easily or at a high frequency, a new anti-influenza strategy will be necessary. This study aimed to investigate if and to what extent NA inhibitor–resistant mutants exist in the wild population of influenza A viruses that inhabit wild birds. NA sequences of all NA subtypes available from 5490 avian, 379 swine and 122 environmental isolates were extracted from NCBI databases. In addition, a dataset containing 230 virus isolates from mallard collected at Ottenby Bird Observatory (Öland, Sweden) was analyzed. Isolated NA RNA fragments from Ottenby were transformed to cDNA by RT-PCR, which was followed by sequencing. The analysis of genotypic profiles for NAs from both data sets in regard to antiviral resistance mutations was performed using bioinformatics tools. All 6221 sequences were scanned for oseltamivir- (I117V, E119V, D198N, I222V, H274Y, R292K, N294S and I314V) and zanamivir-related mutations (V116A, R118K, E119G/A/D, Q136K, D151E, R152K, R224K, E276D, R292K and R371K). Of the sequences from the avian NCBI dataset, 132 (2.4%) carried at least one, or in two cases even two and three, NA inhibitor resistance mutations. Swine and environmental isolates from the same data set had 18 (4.75%) and one (0.82%) mutant, respectively, with at least one mutation. The Ottenby sequences carried at least one mutation in 15 cases (6.52%). Therefore, resistant strains were more frequently found in Ottenby samples than in NCBI data sets. However, it is still uncertain if these mutations are the result of natural variations in the viruses or if they are induced by the selective pressure of xenobiotics (e.g., oseltamivir, zanamivir)
Transient Expression of Hemagglutinin Antigen from Low Pathogenic Avian Influenza A (H7N7) in Nicotiana benthamiana
The influenza A virus is of global concern for the poultry industry, especially the H5 and H7 subtypes as they have the potential to become highly pathogenic for poultry. In this study, the hemagglutinin (HA) of a low pathogenic avian influenza virus of the H7N7 subtype isolated from a Swedish mallard Anas platyrhynchos was sequenced, characterized and transiently expressed in Nicotiana benthamiana. Recently, plant expression systems have gained interest as an alternative for the production of vaccine antigens. To examine the possibility of expressing the HA protein in N. benthamiana, a cDNA fragment encoding the HA gene was synthesized de novo, modified with a Kozak sequence, a PR1a signal peptide, a C-terminal hexahistidine (6×His) tag, and an endoplasmic retention signal (SEKDEL). The construct was cloned into a Cowpea mosaic virus (CPMV)-based vector (pEAQ-HT) and the resulting pEAQ-HT-HA plasmid, along with a vector (pJL3:p19) containing the viral gene-silencing suppressor p19 from Tomato bushy stunt virus, was agro-infiltrated into N. benthamiana. The highest gene expression of recombinant plant-produced, uncleaved HA (rHA0), as measured by quantitative real-time PCR was detected at 6 days post infiltration (dpi). Guided by the gene expression profile, rHA0 protein was extracted at 6 dpi and subsequently purified utilizing the 6×His tag and immobilized metal ion adsorption chromatography. The yield was 0.2 g purified protein per kg fresh weight of leaves. Further molecular characterizations showed that the purified rHA0 protein was N-glycosylated and its identity confirmed by liquid chromatography-tandem mass spectrometry. In addition, the purified rHA0 exhibited hemagglutination and hemagglutination inhibition activity indicating that the rHA0 shares structural and functional properties with native HA protein of H7 influenza virus. Our results indicate that rHA0 maintained its native antigenicity and specificity, providing a good source of vaccine antigen to induce immune response in poultry species
An Interspecific Nicotiana Hybrid as a Useful and Cost-Effective Platform for Production of Animal Vaccines
The use of transgenic plants to produce novel products has great biotechnological potential as the relatively inexpensive inputs of light, water, and nutrients are utilised in return for potentially valuable bioactive metabolites, diagnostic proteins and vaccines. Extensive research is ongoing in this area internationally with the aim of producing plant-made vaccines of importance for both animals and humans. Vaccine purification is generally regarded as being integral to the preparation of safe and effective vaccines for use in humans. However, the use of crude plant extracts for animal immunisation may enable plant-made vaccines to become a cost-effective and efficacious approach to safely immunise large numbers of farm animals against diseases such as avian influenza. Since the technology associated with genetic transformation and large-scale propagation is very well established in Nicotiana, the genus has attributes well-suited for the production of plant-made vaccines. However the presence of potentially toxic alkaloids in Nicotiana extracts impedes their use as crude vaccine preparations. In the current study we describe a Nicotiana tabacum and N. glauca hybrid that expresses the HA glycoprotein of influenza A in its leaves but does not synthesize alkaloids. We demonstrate that injection with crude leaf extracts from these interspecific hybrid plants is a safe and effective approach for immunising mice. Moreover, this antigen-producing alkaloid-free, transgenic interspecific hybrid is vigorous, with a high capacity for vegetative shoot regeneration after harvesting. These plants are easily propagated by vegetative cuttings and have the added benefit of not producing viable pollen, thus reducing potential problems associated with bio-containment. Hence, these Nicotiana hybrids provide an advantageous production platform for partially purified, plant-made vaccines which may be particularly well suited for use in veterinary immunization programs
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