392 research outputs found
Magnetic-assisted treatment of liver fibrosis
No full textChronic liver injury can be induced by viruses, toxins, cellular activation, and metabolic dysregulation and can lead to liver fibrosis. Hepatic fibrosis still remains a major burden on the global health systems. Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are considered the main cause of liver fibrosis. Hepatic stellate cells are key targets in antifibrotic treatment, but selective engagement of these cells is an unresolved issue. Current strategies for antifibrotic drugs, which are at the critical stage 3 clinical trials, target metabolic regulation, immune cell activation, and cell death. Here, we report on the critical factors for liver fibrosis, and on prospective novel drugs, which might soon enter the market. Apart from the current clinical trials, novel perspectives for anti-fibrotic treatment may arise from magnetic particles and controlled magnetic forces in various different fields. Magnetic-assisted techniques can, for instance, enable cell engineering and cell therapy to fight cancer, might enable to control the shape or orientation of single cells or tissues mechanically. Furthermore, magnetic forces may improve localized drug delivery mediated by magnetism-induced conformational changes, and they may also enhance non-invasive imaging applications
Adsorption of Copper Ions on the Surface of Multilayer Ti3C2Tx MXenes with Mixed Functionalization
No full textNowadays a new class of two-dimensional materials, MXenes, is attracting considerable attention as nanoadsorbents for the removal of heavy-metal ions from water. Pollutants such as copper and other heavy metals possess a negative impact on human health and the quality of natural ecosystems when their concentration exceeds an acceptable limit, which makes it urgent to develop cheap and effective methods to reduce the concentration of such pollutants. In this work we study the adsorptive properties of Ti3C2Tx MXenes with mixed functionalization by –O, –F, and –OH surface groups in relation to copper Cu(II) ions. Herein, multilayer MXene particles are investigated, since their yield is much greater than that of single-layer particles when using standard synthesis methods, and the experimental results are compared with previously published data for single-layer MXenes. It is established that, at low concentrations (below 50 mg/L), multilayer Ti3C2Tx MXenes demonstrate a comparable adsorption capacity of ~102 mg/g which makes it possible to use them for practical applications
Methyl orange sorption on octadecylamine-modified iron oxide magnetic nanoparticles
No full textThis study investigates the sorption of 2-methyl orange dye onto octadecylamine-modified iron oxide magnetic nanoparticles (ODA-IONPs). The synthesized ODA-IONPs exhibit remarkable sorption capacity, reaching 800 mg/g at the nanoparticle concentrations ranging from 5 to 10 mg/g and pH of 2–8. The sorption process demonstrates rapid kinetics, achieving 90% of maximum sorption within 0.5 min. Thermodynamic analysis showed that sorption process is spontaneous and endothermic, as indicated by negative ΔG and positive ΔH values. The pseudo-second-order and Langmuir models best describe the sorption kinetics at 293 K (R2 > 0.99). Compared to other adsorbents, ODA-IONPs show superior MO removal capacity under a wider pH range. The influence of nanoparticle concentration, pH, and temperature on sorption efficiency is systematically explored, with optimal conditions identified at 10 mg/L ODA-IONPs and pH 6. Furthermore, the feasibility of nanoparticle reusability for sorption purposes is assessed. These findings underscore the potential of ODA-IONPs as efficient sorbents for wastewater treatment and environmental remediation applications
Promoting the adaptation of 1.5 - 3-year-olds to a preschool education institution
No full textDarba nosaukums: 1,5-3 gadīgu bērnu adaptācijas veicināšana pirmsskolas izglītības iestādē Darba autore: Ilga Rodionova Darba mērķis: teorētiski izzināt un praktiski pētīt 1,5-3 gadīgu bērnu adaptācijas veicināšanu pirmsskolas izglītības iestādē. Pētījuma teorētiskajā daļā: tika aprakstīta adaptācijas procesa būtība, analizētas 1,5-3 gadīgu bērnu vecuma attīstības īpatnības un adaptācijas norisi, ka arī izzināta spēles un rotaļa bērnu attīstībā. Teorētiskajā literatūra analizēti tādu autoru darbi, kā D. Lieģeniece, I.Jurgena, I. Puškarevs, A.Golubeva, S.Gailuma, Dž. Boulbijs, I.Stangaine, D.Dzintere. Pētījuma empīriskajā daļā: tika veikta pirmsskolas izglītības iestādes 1,5-3 gadu vecu bērnu novērošana, viņu vecāku anketēšana, kā arī iegūtu datu analīze. Analizēta bērnu adaptācijas norise un meklēti veidi un paņēmieni, kā palīdzēt bērnam veiksmīgāk adaptēties. Darbs sastāv: no 35 lapaspusēm, tajā iekļauti 7 attēli, un 3 tabulas, darbam pievienoti 2 pielikumi. Darbā tika izmantoti 26 literatūras avoti (22 latviešu valoda un 4 svešvaloda) Atslēgas vārdi: adaptācija, saskarsme, bērnu vajadzības, drošības izjūta, rotaļa.The title of the work: Promoting the adaptation of 1.5 - 3-year-olds to a preschool education institution. The author of the work: Ilga Rodionova Aim of the research: theoretical study and practical study of the promotion of the adaptation of 1.5-3-year-olds in a preschool education institution The reserch work consist of 2 parts – theoretical andempirical The theoretical part of the research work explores nature of the adaptation process was described, analysing the specificities of the development of the age of 1.5-3-year-olds and the adaptation process, as well as the learning of games and games in children's development. The theoretical literature analyses the works of authors such as D. Liegeniece, I. Jurgena, I. Pushkarev, A.Golubeva, S.Gailuma, J. Boulby, I.Stangaine, D.Dzintere. The empirical part of the research work monitoring of children aged 1.5-3 in the preschool was carried out, testing of their parents, as well as analysis of the resulting data. The process of adapting children and looking for ways and ways to help the child adapt more successfully. The work consists of 35 pages included 7 pictures, 3 tables and 2 attachments. 26 sources of literature were used ( 22 latvian language, 4 foreign language) Keywords: adaptation, contact, needs of children, sense of safety, play
Tuning the magnetic properties of permalloy-based magnetoplasmonic crystals for sensor applications
No full textM. Rivas acknowledges the support of the
Principality of Asturias under project IDI/2018/000185.
V. V. Rodionova acknowledges financial support from the Russian Ministry of Education and Science in the framework of Government Assignment 3.4168.2017/4.6
Ultrasensitive magnetic field sensors for biomedical applications
No full textThe development of magnetic field sensors for biomedical applications primarily focuses on equivalent magnetic noise reduction or overall design improvement in order to make them smaller and cheaper while keeping the required values of a limit of detection. One of the cutting-edge topics today is the use of magnetic field sensors for applications such as magnetocardiography, magnetotomography, magnetomyography, magnetoneurography, or their application in point-of-care devices. This introductory review focuses on modern magnetic field sensors suitable for biomedicine applications from a physical point of view and provides an overview of recent studies in this field. Types of magnetic field sensors include direct current superconducting quantum interference devices, search coil, fluxgate, magnetoelectric, giant magneto-impedance, anisotropic/giant/tunneling magnetoresistance, optically pumped, cavity optomechanical, Hall effect, magnetoelastic, spin wave interferometry, and those based on the behavior of nitrogen-vacancy centers in the atomic lattice of diamond
Adsorptive Properties of Ti3C2Tx MXenes with Optimal Surface Functionalization by (‒O, ‒F) Groups
No full textNanoadsorbents, including 2D MХenes, are being actively studied as materials for the removal of heavy metals from water. Adsorption is a cheap and effective way to reduce the pollution level with such-kind toxic substances. Ti3C2Tx MXenes are one of the most promising materials in this field, due to their large specific surface area rich in adsorption centers. Additionally, the composition of this material can be optimally selected to ensure the maximum adsorption efficiency, for example, by controlling their surface functionalization. Density functional theory (DFT) modeling is one of the most effective methods for studying and predicting the adsorption properties of MXenes. In this work, the DFT approach is used to determine the adsorption energies (Eads) of mercury and iron ions on the surface of Ti3C2O2 and Ti3C2F2 MXenes. It is found that the maximum adsorption energy (Eads = –3.59 eV for Fe and –0.357 eV for Hg) is exhibited by MXenes with oxygen surface functionalization. Also, the work describes the synthesis and characterization of Ti3C2Tx MXenes with a predominant content of –O functional groups. Characterization of the material includes the study of its optical properties, i.e., absorption spectra: their analysis is a simple way to subsequently detect the content of MXenes in treated water. It is found that Ti3C2Tx MXenes have a light-absorption peak at a wavelength of 795 nm, and the dependence of the intensity of this peak on the concentration is linear in the range from 10 to 100 μg/mL, which is convenient for subsequent use in optical detection
Complex optimization of arc melting synthesis for bulk Cr2AlC MAX-phase
No full textA complex optimization of the arc melting synthetic approach was performed to enhance the phase purity of Cr2AlC MAX-phase in the bulk form. Optimization steps included the initial ratio of 2Cr: xAl: 1C, variation through a change in Al content (i.e. x ranging from 1 to 1.5), tuning duration of the post-annealing thermal treatment and adjustment of the melting chamber pressure. The use of Cr3C2 as a precursor in place of Cr and C mixture has also been tried. It was found that Cr2AlC MAX-phase forms as the predominant phase when a stoichiometric ratio 2Cr: 1.3Al: 1C is used. By keeping this stoichiometry constant, the melting chamber pressure was then adjusted to further improve the phase purity of the samples. It has been established that the use of Cr3C2 is not an appropriate way to improve sample purity and promote homogeneity in the carbon distribution. The establishment of an optimized arc fusion protocol for parental Cr2AlC is a necessity for further successful mass synthesis of the substituted (Cr1-xMnx)2AlC MAX-phase
Synthesis of phase-pure highly-doped MAX-phase (Cr1-xMnx)2AlC
No full textMn doped (Cr1-xMnx)2AlC compounds constitute a family of MAX-phases of great interest due to the possibility of tuning the magnetic properties they possess. Their synthesis, however, is not an easy task. Two main issues make its preparation difficult. First is the strong tendency secondary phases have to segregate when manganese is added to the parent compound and, secondly, the resulting doping level which remains relatively low due to the poor incorporation of Mn atoms into the MAX-phase hexagonal structure [Cr2AlC-type]. In the present work the highest dopant concentration so far reported for bulk materials of 18.3 at.% Mn has been obtained through the exploitation of the arc-melting technique. At the same time, the use of the Cr3C2, as a precursor from the initial stage of the synthesis procedure, led to the preservation of the phase content in the Mn-doped samples. Finally, chemical post-treatment in acid solutions (HF, HCl) proved to be effective and helpful to dissolve the remaining secondary intermetallic phases; the final material resulting in a pure MAX-phase powder (>99 vol%). However, the doping level reached seems to be the limit for the arc fusion technique used; additional manganese no longer dissolves into the MAX-phase structure but tends to form some new Mn-based secondary phases, such as the perovskite Mn3AlC and the carbide MnC2. After the chemical etching, pure MAX-phase powders can be compacted into bulk using spark plasma sintering technique. However, while this method is useful for the non-doped Cr2AlC, it needs further optimization for (Cr1-xMnx)2AlC as it leads to a partial decomposition of Mn-containing MAX-phase
Spatial Manipulation of Particles and Cells at Micro-and Nanoscale via Magnetic Forces
No full textThe importance of magnetic micro-and nanoparticles for applications in biomedical technology is widely recognised. Many of these applications, including tissue engineering, cell sorting, biosensors, drug delivery, and lab-on-chip devices, require remote manipulation of magnetic objects. High-gradient magnetic fields generated by micromagnets in the range of 103 –105 T/m are sufficient for magnetic forces to overcome other forces caused by viscosity, gravity, and thermal fluctuations. In this paper, various magnetic systems capable of generating magnetic fields with required spatial gradients are analysed. Starting from simple systems of individual magnets and methods of field computation, more advanced magnetic microarrays obtained by lithography patterning of permanent magnets are introduced. More flexible field configurations can be formed with the use of soft magnetic materials magnetised by an external field, which allows control over both temporal and spatial field distributions. As an example, soft magnetic microwires are considered. A very attractive method of field generation is utilising tuneable domain configurations. In this review, we discuss the force requirements and constraints for different areas of application, emphasising the current challenges and how to overcome them
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