103 research outputs found

    Изменение параметров прокатки при скоростях валков менее 1 м/с

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    Приведены результаты экспериментальных исследований по влиянию скорости прокатки на контактные касательные напряжения и коэффициент трения в очаге деформации. Опытами установлено, что с увеличением скорости валков от 0,2 до 0,8 м/с при прокатке полос с технологической смазкой опережение и коэффициент трения существенно уменьшаются; при прокатке полос в сухих валках величины опережения и коэффициента трения возрастают с увеличением скорости прокатки v до 0,5 м/с, а при прокатке с v > 0,5 м/с параметры стабилизируются. Дано физическое толкование изменения исследуемых параметров.Наведено результати експериментальних досліджень по впливу швидкості прокатки на контактні дотичні напруження і коефіцієнт тертя в осередку деформації. Дослідами встановлено, що при збільшенні швидкості валків від 0,2 до 0,8 м/с при прокатуванні штаб із технологічним мастилом випередження і коефіцієнт тертя істотно зменшуються; при прокатуванні штаб у сухих валках величини випередження і коефіцієнта тертя зростають при збільшенні швидкості прокатки v до 0,5 м/с, а при прокатуванні з v > 0,5 м/с параметри стабілізуються. Наведено фізичне тлумачення зміни досліджуваних параметрів.The tests investigation results of rolling velocity influence on contact tangents strain and fiction coefficient in the point (site) of deformation are concerned. It was determined by experiments that with increasing of rolls velocity from 0,2 to 0,8 m/s while strips are being rolled with rolling lubricant, the forward creep and friction coefficient are clearly reduction. But while strips are being rolled in dry rolls the value of forward creep and friction coefficient are rising with an increase of rolling velocity to ≈ 0,5 m/s. At the same time when rolling velocity excesses 0,5 m/s, the given parameters are stafilized. Physical explanation of the investigated parameters is given

    In vitro evaluation of defined oligosaccharide fractions in an equine model of inflammation

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    Background: Dietary supplementation with oligosaccharides has been proven to be beneficial for health in several mammalian species. Next to prebiotic effects resulting in a modulation of gut micro biota, immunomodulatory effects of oligosaccharides have been documented in vivo. Supplementation with defined oligosaccharide fractions has been shown to attenuate allergic responses and enhance defensive immune responses. Despite the accumulating evidence for immunomodulatory effects, very limited information is available regarding the direct mechanism of action of oligosaccharides. This study aims to elucidate the effects of selected oligosaccharide fractions on the lipopolysaccharide (LPS) induced inflammatory response in equine peripheral blood mononuclear cells (PBMCs). We investigated three different products containing either galacto-oligosaccharides (GOS) alone, a combination of GOS with fructo-oligosaccharides (FOS), and a triple combination of GOS and FOS with acidic oligosaccharides (AOS), at different concentrations. These products have been used in an identical composition in various previously published in vivo experiments. As the selected oligosaccharide fractions were derived from natural products, the fractions contained defined amounts of mono- and disaccharides and minor amounts of endotoxin, which was taken into account in the design of the study and the analysis of data. Acquired data were analysed in a Bayesian hierarchical linear regression model, accounting for variation between horses.Results: Exposing cultured PBMCs to either GOS or GOS/FOS fractions resulted in a substantial dose-dependent increase of tumour necrosis factor-α (TNF-α) production in LPS challenged PBMCs. In contrast, incubation with GOS/FOS/AOS resulted in a dose-dependent reduction of both TNF-α and interleukin-10 production following LPS challenge. In addition, incubation with GOS/FOS/AOS significantly increased the apparent PBMC viability, indicating a protective or mitogenic effect. Furthermore, mono- and disaccharide control fractions significantly stimulated the inflammatory response in LPS challenged PBMCs as well, though to a lesser extent than GOS and GOS/FOS fractions.Conclusions: We found distinct immunomodulating effects of the investigated standardised oligosaccharide fractions, which either stimulated or suppressed the LPS induced inflammatory response in PBMCs. Both scenarios require additional investigation, to elucidate underlying modulatory mechanisms, and to translate this knowledge into the clinical application of oligosaccharide supplements in foals and other neonates

    Epithelial integrity, junctional complexes, and biomarkers associated with intestinal functions

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    An intact intestinal barrier is crucial for immune homeostasis and its impairment activates the immune system and may result in chronic inflammation. The epithelial cells of the intestinal barrier are connected by tight junctions, which form an anastomosing network sealing adjacent epithelial cells. Tight junctions are composed of transmembrane and cytoplasmic scaffolding proteins. Transmembrane tight junction proteins at the apical-lateral membrane of the cell consist of occludin, claudins, junctional adhesion molecules, and tricellulin. Cytoplasmic scaffolding proteins, including zonula occludens, cingulin and afadin, provide a direct link between transmembrane tight junction proteins and the intracellular cytoskeleton. Each individual component of the tight junction network closely interacts with each other to form an efficient intestinal barrier. This review aims to describe the molecular structure of intestinal epithelial tight junction proteins and to characterize their organization and interaction. Moreover, clinically important biomarkers associated with impairment of gastrointestinal integrity are discussed

    The intestinal barrier as an emerging target in the toxicological assessment of mycotoxins

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    Mycotoxins, the secondary metabolites of fungal species, are the most frequently occurring natural food contaminants in human and animal diets. Risk assessment of mycotoxins focused as yet on their mutagenic, genotoxic and potential carcinogenic effects. Recently, there is an increasing awareness of the adverse effects of various mycotoxins on vulnerable structures in the intestines. In particular, an impairment of the barrier function of the epithelial lining cells and the sealing tight junction proteins has been noted, as this could result in an increased translocation of luminal antigens and pathogens and an excessive activation of the immune system. The current review aims to provide a summary of the available evidence regarding direct effects of various mycotoxins on the intestinal epithelial barrier. Available data, based on different cellular and animal studies, show that food-associated exposure to certain mycotoxins, especially trichothecenes and patulin, affects the intestinal barrier integrity and can result in an increased translocation of harmful stressors. It is therefore hypothesized that human exposure to certain mycotoxins, particularly deoxynivalenol, as the major trichothecene, may play an important role in etiology of various chronic intestinal inflammatory diseases, such as inflammatory bowel disease, and in the prevalence of food allergies, particularly in children

    Возможности использования ксеноселезенки в клинической практике

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    Рассмотрена проблема применения ксеноселезенки в клинике. Показана целесообразность применения криобиологических технологий для получения биологически активных экстрактов из фрагментов ксеноселезенки. Разработан такой экстракт, определены его биофармацевтические свойства и клиническая эффективность при эндобронхиальном введении больным с абсцессами легких.The problem of xenospleen use in clinical practice is discussed. Reasonability of application of cryobiological technologies to obtain biologically active extracts from xenospleen fragments is shown. The extract has been developed, its biopharmaceutical properties and clinical efficacy at endobronchial administration in patients with lung abscess is shown

    Storage Fungi and Mycotoxins Associated with Rice Samples Commercialized in Thailand

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    The study focused on the examination of the different fungal species isolated from commercial rice samples, applying conventional culture techniques, as well as different molecular and phylogenic analyses to confirm phenotypic identification. Additionally, the mycotoxin production and contamination were analyzed using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS). In total, 40 rice samples were obtained covering rice berry, red jasmine rice, brown rice, germinated brown rice, and white rice. The blotting paper technique applied on the 5 different types of rice samples detected 4285 seed-borne fungal infections (26.8%) for 16,000 rice grains. Gross morphological data revealed that 19 fungal isolates belonged to the genera Penicillium/Talaromyces (18 of 90 isolates; 20%) and Aspergillus (72 of 90 isolates; 80%). To check their morphologies, molecular data (fungal sequence-based BLAST results and a phylogenetic tree of the combined ITS, BenA, CaM, and RPB2 datasets) confirmed the initial classification. The phylogenic analysis revealed that eight isolates belonged to P. citrinum and, additionally, one isolate each belonged to P. chermesinum, A. niger, A. fumigatus, and A. tubingensis. Furthermore, four isolates of T. pinophilus and one isolate of each taxon were identified as Talaromyces ( T. radicus, T. purpureogenum, and T. islandicus). The results showed that A. niger and T. pinophilus were two commonly occurring fungal species in rice samples. After subculturing, ochratoxin A (OTA), generated by T. pinophilus code W3-04, was discovered using LC-MS/MS. In addition, the Fusarium toxin beauvericin was detected in one of the samples. Aflatoxin B1 or other mycotoxins, such as citrinin, trichothecenes, and fumonisins, were detected. These preliminary findings should provide valuable guidance for hazard analysis critical control point concepts used by commercial food suppliers, including the analysis of multiple mycotoxins. Based on the current findings, mycotoxin analyses should focus on A. niger toxins, including OTA and metabolites of T. pinophilus (recently considered a producer of emerging mycotoxins) to exclude health hazards related to the traditionally high consumption of rice by Thai people

    Стратегічне управління як основа фінансової стійкості аграрних підприємств

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    Метою роботи є формування комплексного стратегічного підходу до управління фінансовою стійкістю аграрних підприємств на основі всебічного аналізу їх діяльності, конкретизації поточних цілей та індикаторів стану, а також розробці системи заходів для досягнення стратегічної мети, в залежності від етапу планування

    Characterizing microbiota-independent effects of oligosaccharides on intestinal epithelial cells: insight into the role of structure and size: Structure–activity relationships of non-digestible oligosaccharides

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    Purpose: The direct effects of galacto-oligosaccharides (GOS), including Vivinal® GOS syrup (VGOS) and purified Vivinal® GOS (PGOS), on the epithelial integrity and corresponding interleukin-8 (IL-8/CXCL8) release were examined in a Caco-2 cell model for intestinal barrier dysfunction. To investigate structure–activity relationships, the effects of individual DP fractions of VGOS were evaluated. Moreover, the obtained results with GOS were compared with Caco-2 monolayers incubated with fructo-oligosaccharides (FOS) and inulin. Methods: Caco-2 monolayers were pretreated (24 h) with or without specific oligosaccharides or DP fractions of VGOS (DP2 to DP6) before being exposed for 12 or 24 h to the fungal toxin deoxynivalenol (DON). Transepithelial electrical resistance and lucifer yellow permeability were measured to investigate barrier integrity. A calcium switch assay was used to study the reassembly of tight junction proteins. Release of CXCL8, a typical marker for inflammation, was quantified by ELISA. Results: In comparison with PGOS, FOS and inulin, VGOS showed the most pronounced protective effect on the DON-induced impairment of the monolayer integrity, acceleration of the tight junction reassembly and the subsequent CXCL8 release. DP2 and DP3 in concentrations occurring in VGOS prevented the DON-induced epithelial barrier disruption, which could be related to their high prevalence in VGOS. However, no effects of the separate DP GOS fractions were observed on CXCL8 release. Conclusions: This comparative study demonstrates the direct, microbiota-independent effects of oligosaccharides on the intestinal barrier function and shows the differences between individual galacto- and fructo-oligosaccharides. This microbiota-independent effect of oligosaccharides depends on the oligosaccharide structure, DP length and concentration

    Effects of Separate and Concomitant TLR-2 and TLR-4 Activation in Peripheral Blood Mononuclear Cells of Newborn and Adult Horses

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    Deficient innate and adaptive immune responses cause newborn mammals to be more susceptible to bacterial infections than adult individuals. Toll-like receptors (TLRs) are known to play a pivotal role in bacterial recognition and subsequent immune responses. Several studies have indicated that activation of certain TLRs, in particular TLR-2, can result in suppression of inflammatory pathology. In this study, we isolated peripheral blood mononuclear cells (PBMCs) from adult and newborn horses to investigate the influence of TLR-2 activation on the inflammatory response mediated by TLR-4. Data were analysed in a Bayesian hierarchical linear regression model, accounting for variation between horses. In general, cytokine responses were lower in PBMCs derived from foals compared with PBMCs from adult horses. Whereas in foal PBMCs expression of TLR-2, TLR-4, and TLR-9 was not influenced by separate and concomitant TLR-2 and TLR-4 activation, in adult horse PBMCs, both TLR ligands caused significant up-regulation of TLR-2 and down-regulation of TLR-9. Moreover, in adult horse PBMCs, interleukin-10 protein production and mRNA expression increased significantly following concomitant TLR-2 and TLR-4 activation (compared with sole TLR-4 activation). In foal PBMCs, this effect was not observed. In both adult and foal PBMCs, the lipopolysaccharide-induced pro-inflammatory response was not influenced by pre-incubation and co-stimulation with the specific TLR-2 ligand Pam3-Cys-Ser-Lys4. This indicates that the published data on other species cannot be translated directly to the horse, and stresses the necessity to confirm results obtained in other species in target animals. Future research should aim to identify other methods or substances that enhance TLR functionality and bacterial defence in foals, thereby lowering susceptibility to life-threatening infections during the first period of life
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