102 research outputs found
Study of the structure of intermetalics from Fe - Al system after the hot rolling
This paper presents the results of structure analysis of Fe - Al alloys after hot rolling deformation. Microstructure analysis were performed before and after deformation using a scanning transmission electron microscopy (STEM) technique. The detailed quantities research of the structures was conducted using scanning electron microscopy (SEM) equipped with the gun with cold field emission and the detector of electron back scattering diffraction (EBSD)
Критерії оцінювання проектних завдань у процесі навчання творчим дисциплінам
In this paper, we were considered the importance of evaluation and the main problems faced by the "assessor" in assessing the work of a creative component, namely subjectivity. The importance of clear criteria for evaluation a better understanding and objective evaluation of work, and therefore the educational process and education in general.В статье рассмотрена важность процесса оценивания и основные проблемы, с которыми сталкивается преподаватель при оценке работ с творческой составляющей, а именно субъективность. Показана важность наличия четких критериев оценивания в улучшении понимания и объективности оценивания работ, а соответственно учебного процесса и образования в целом.У даній роботі була розглянута важливість процесу оцінювання та основні проблеми, з якими стикається викладач при оцінці роботи з творчою складовою, а саме суб'єктивність. Показана важливість наявності чітких критеріїв оцінювання в поліпшенні розуміння і об'єктивності оцінювання робіт, і, відповідно, навчального процесу та освіти в цілому
Electrochemical formation of self-organized nanotubular oxide layers on Ti13Zr13Nb alloy for biomedical applications
In this work, the anodic formation of self-organized nanotubular oxide layers on Ti13Zr13Nb implant alloy
was presented. Anodic oxidation was carried out at room temperature in [1 M] (NH4)2SO4 solution with 1 wt%
content of NH4F. The voltage and time of anodization was 20 V for 120 min, respectively. Under proposed
conditions, the best arrangement of nanopores was observed. The physical and chemical properties of the anodized surface of the Ti13Zr13Nb alloy were characterized using grazing incidence X-ray di raction, scanning transmission electron microscopy, and atomic force microscopy. It was found that diameter of nanopores varied from 10 to 32 nm. Mechanism of the fabrication of the unique 3D tube-shaped nanostructure of TiO2 on the surface of the Ti13Zr13Nb alloy by electrochemical anodization, has been discussed
Gene expression analysis of cell death induction by Taurolidine in different malignant cell lines
<p>Abstract</p> <p>Background</p> <p>The anti-infective agent Taurolidine (TRD) has been shown to have cell death inducing properties, but the mechanism of its action is largely unknown. The aim of this study was to identify potential common target genes modulated at the transcriptional level following TRD treatment in tumour cell lines originating from different cancer types.</p> <p>Methods</p> <p>Five different malignant cell lines (HT29, Chang Liver, HT1080, AsPC-1 and BxPC-3) were incubated with TRD (100 μM, 250 μM and 1000 μM). Proliferation after 8 h and cell viability after 24 h were analyzed by BrdU assay and FACS analysis, respectively. Gene expression analyses were carried out using the <it>Agilent </it>-microarray platform to indentify genes which displayed conjoint regulation following the addition of TRD in all cell lines. Candidate genes were subjected to <it>Ingenuity Pathways Analysis </it>and selected genes were validated by qRT-PCR and Western Blot.</p> <p>Results</p> <p>TRD 250 μM caused a significant inhibition of proliferation as well as apoptotic cell death in all cell lines. Among cell death associated genes with the strongest regulation in gene expression, we identified pro-apoptotic transcription factors (EGR1, ATF3) as well as genes involved in the ER stress response (PPP1R15A), in ubiquitination (TRAF6) and mitochondrial apoptotic pathways (PMAIP1).</p> <p>Conclusions</p> <p>This is the first conjoint analysis of potential target genes of TRD which was performed simultaneously in different malignant cell lines. The results indicate that TRD might be involved in different signal transduction pathways leading to apoptosis.</p
Comparative study of fungal cell disruption—scope and limitations of the methods
Simple and effective protocols of cell wall disruption were elaborated for tested fungal strains: Penicillium citrinum, Aspergillus fumigatus, Rhodotorula gracilis. Several techniques of cell wall disintegration were studied, including ultrasound disintegration, homogenization in bead mill, application of chemicals of various types, and osmotic shock. The release of proteins from fungal cells and the activity of a cytosolic enzyme, glucose-6-phosphate dehydrogenase, in the crude extracts were assayed to determine and compare the efficacy of each method. The presented studies allowed adjusting the particular method to a particular strain. The mechanical methods of disintegration appeared to be the most effective for the disintegration of yeast, R. gracilis, and filamentous fungi, A. fumigatus and P. citrinum. Ultrasonication and bead milling led to obtaining fungal cell-free extracts containing high concentrations of soluble proteins and active glucose-6-phosphate dehydrogenase systems
Histo-Blood Group Antigens Act as Attachment Factors of Rabbit Hemorrhagic Disease Virus Infection in a Virus Strain-Dependent Manner
Rabbit Hemorrhagic disease virus (RHDV), a calicivirus of the Lagovirus genus, and responsible for rabbit hemorrhagic disease (RHD), kills rabbits between 48 to 72 hours post infection with mortality rates as high as 50–90%. Caliciviruses, including noroviruses and RHDV, have been shown to bind histo-blood group antigens (HBGA) and human non-secretor individuals lacking ABH antigens in epithelia have been found to be resistant to norovirus infection. RHDV virus-like particles have previously been shown to bind the H type 2 and A antigens. In this study we present a comprehensive assessment of the strain-specific binding patterns of different RHDV isolates to HBGAs. We characterized the HBGA expression in the duodenum of wild and domestic rabbits by mass spectrometry and relative quantification of A, B and H type 2 expression. A detailed binding analysis of a range of RHDV strains, to synthetic sugars and human red blood cells, as well as to rabbit duodenum, a likely gastrointestinal site for viral entrance was performed. Enzymatic cleavage of HBGA epitopes confirmed binding specificity. Binding was observed to blood group B, A and H type 2 epitopes in a strain-dependent manner with slight differences in specificity for A, B or H epitopes allowing RHDV strains to preferentially recognize different subgroups of animals. Strains related to the earliest described RHDV outbreak were not able to bind A, whereas all other genotypes have acquired A binding. In an experimental infection study, rabbits lacking the correct HBGA ligands were resistant to lethal RHDV infection at low challenge doses. Similarly, survivors of outbreaks in wild populations showed increased frequency of weak binding phenotypes, indicating selection for host resistance depending on the strain circulating in the population. HBGAs thus act as attachment factors facilitating infection, while their polymorphism of expression could contribute to generate genetic resistance to RHDV at the population level
- …