magnetometry
Dotaz
Zobrazit nápovědu
The primary goal of this work was to distinguish between soil pollution from long-range and local transport of atmospheric pollutants using soil magnetometry supported by geochemical analyses. The study area was located in the Izery region of Poland (within the "Black Triangle" region, which is the nickname for one of Europe's most polluted areas, where Germany, Poland and the Czech Republic meet). One site of the study area was situated in the Forest Glade and was exposed to anthropogenic pollution from a former glasswork. The second site of the study area was located on a neighboring hill (Granicznik) of which the western, northwestern and southwestern parts of the slope were exposed to the long-range transport of atmospheric pollutants from the Czech Republic, Germany and Poland. Magnetic susceptibility was measured on the soil surface and in the soil samples using a MS2 Bartington meter equipped with MS2D and MS2C sensors, respectively. Using soil magnetometry, it was possible to discriminate between long-range transport of atmospheric pollutants and anthropogenic pollution related to the former glasswork located in the Forest Glade. Additionally, using MS2C measurements and geochemical analyses of sixteen trace elements, it was possible to discriminate between natural and anthropogenic origins of a soil magnetic susceptibility signal. Our results indicate that the Forest Glade site is characterized by relatively significant anthropogenic translocation of topsoil horizons, presence of artefacts, more hot spots, very high spatial variability, and higher nugget effect than on the Granicznik Hill.
- MeSH
- látky znečišťující půdu analýza MeSH
- látky znečišťující vzduch analýza MeSH
- magnetometrie * MeSH
- monitorování životního prostředí metody statistika a číselné údaje MeSH
- půda chemie MeSH
- stopové prvky analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Německo MeSH
- Polsko MeSH
Iron is an essential element for fundamental cell functions and a catalyst for chemical reactions. Three samples extracted from the human spleen were investigated by scanning (SEM) and transmission electron microscopy (TEM), Mössbauer spectrometry (MS), and SQUID magnetometry. The sample with diagnosis of hemosiderosis (H) differs from that referring to hereditary spherocytosis and the reference sample. SEM reveals iron-rich micrometer-sized aggregate of various structures-tiny fibrils in hereditary spherocytosis sample and no fibrils in hemochromatosis. Hematite and magnetite particles from 2 to 6 μm in TEM with diffraction in all samples were shown. The SQUID magnetometry shows different amount of diamagnetic, paramagnetic and ferrimagnetic structures in the tissues. The MS results indicate contribution of ferromagnetically split sextets for all investigated samples. Their occurrence indicates that at least part of the sample is magnetically ordered below the critical temperature. The iron accumulation process is different in hereditary spherocytosis and hemosiderosis. This fact may be the reason of different iron crystallization.
- MeSH
- dědičná sférocytóza metabolismus patologie MeSH
- hemosideróza metabolismus patologie MeSH
- krystalizace MeSH
- lidé MeSH
- oxid železnato-železitý chemie MeSH
- pitva MeSH
- slezina chemie metabolismus patologie ultrastruktura MeSH
- spektroskopie Mossbauerova MeSH
- transmisní elektronová mikroskopie MeSH
- železité sloučeniny chemie metabolismus MeSH
- železo chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Settled road dust was examined to detect the presence of non-airborne submicron and nano-sized iron-based particles and to characterize these particles. Samples were collected from a road surface near a busy road junction in the city of Ostrava, Czech Republic, once a month from March to October. The eight collected samples were subjected to a combination of experimental techniques including elemental analysis, Raman microspectroscopy, scanning electron microscopy (SEM) analysis, and magnetometry. The data thereby obtained confirmed the presence of non-agglomerated spherical nano-sized iron-based particles, with average sizes ranging from 2 down to 490 nm. There are several sources in road traffic which generate road dust particles, including exhaust and non-exhaust processes. Some of them (e.g., brake wear) produce iron as the dominant metallic element. Raman microspectroscopy revealed forms of iron (mainly as oxides, Fe2O3, and mixtures of Fe2O3 and Fe3O4). Moreover, Fe3O4 was also detected in samples of human tissues from the upper and lower respiratory tract. In view of the fact that no agglomeration of those particles was found by SEM, it is supposed that these particles may be easily resuspended and represent a risk to human health due to inhalation exposure, as proved by the detection of particles with similar morphology and phase composition in human tissues.
- MeSH
- dýchací soustava účinky léků metabolismus MeSH
- inhalační expozice analýza MeSH
- lidé MeSH
- monitorování životního prostředí metody MeSH
- oxid železnato-železitý analýza MeSH
- prach analýza MeSH
- velikost částic MeSH
- velkoměsta MeSH
- výfukové emise vozidel analýza MeSH
- železité sloučeniny analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- velkoměsta MeSH
Uniformly sized magnetite nanoparticles (Dn = 16 nm) were prepared by a thermal decomposition of Fe(III) oleate in octadec-1-ene and stabilized by oleic acid. The particles were coated with Sipomer PAM-200 containing both phosphate and methacrylic groups available for the attachment to the iron oxide and at the same time enabling (co)polymerization of 2-(dimethylamino)ethyl methacrylate and/or 2-tert-butylaminoethyl methacrylate at two molar ratios. The poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) and poly[2-(dimethylamino)ethyl methacrylate-co-2-tert-butylaminoethyl methacrylate] [P(DMAEMA-TBAEMA)] polymers and the particles were characterized by 1H NMR spectroscopy, size-exclusion chromatography, transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, magnetometry, and ATR FTIR and atomic absorption spectroscopy. The antimicrobial effect of cationic polymer-coated magnetite nanoparticles tested on both Escherichia coli and Staphylococcus aureus bacteria was found to be time- and dose-responsive. The P(DMAEMA-TBAEMA)-coated magnetite particles possessed superior biocidal properties compared to those of P(DMAEMA)-coated one.
- Publikační typ
- časopisecké články MeSH
Magnetic nanoparticles offer multiple possibilities for biomedical applications. Besides their physico-chemical properties, nanoparticle-cellular interactions are determinant for biological safety. In this work, magnetic nanoparticles were synthesized by one-shot precipitation or two-step reaction and coated with biocompatible polymers, such as poly(l-lysine) and poly(N,N-dimethylacrylamide-co-acrylic acid), and carbohydrates, like l-ascorbic acid, d-galactose, d-mannose, and sucrose. The resulting magnetic nanoparticles were characterized by dynamic light scattering, FT-Raman spectroscopy, transmission electron microscopy, SQUID magnetometry, and Mössbauer spectroscopy. Ability of the nanoparticles to be used in theranostic applications was also evaluated, showing that coating with biocompatible polymers increased the heating efficiency. Nanoparticles synthesized by one-shot precipitation were 50% larger (∼13nm) than those obtained by a two-step reaction (∼8nm). Magnetic nanoparticles at concentrations up to 500μgmL-1 were non-cytotoxic to L929 fibroblasts. Particles synthesized by one-shot precipitation had little effect on viability, cell cycle and apoptosis of the three human colon cancer cell lines used: Caco-2, HT-29, and SW-480. At the same concentration (500μgmL-1), magnetic particles prepared by a two-step reaction reduced colon cancer cell viability by 20%, affecting cell cycle and inducing cell apoptosis. Uptake of surface-coated magnetic nanoparticles by colon cancer cells was dependent on particle synthesis, surface coating and incubation time.
- MeSH
- apoptóza účinky léků MeSH
- biokompatibilní potahované materiály chemie farmakokinetika farmakologie MeSH
- buněčný cyklus účinky léků MeSH
- buňky HT-29 MeSH
- Caco-2 buňky MeSH
- lidé MeSH
- magnetické nanočástice chemie MeSH
- magnetismus * MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory tračníku metabolismus patologie MeSH
- polymery chemie MeSH
- povrchové vlastnosti MeSH
- teranostická nanomedicína metody MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Mucosal surfaces are the first mechanical barrier preventing the entry of foreign particles into the organism. The study addresses the detection and analysis of metal-based solid particles in cytological mucus samples from the surface of human hypertrophic tissue in the inferior nasal turbinates in patients diagnosed with chronic rhinitis. Solid particles were characterized by scanning electron microscopy and Raman microspectroscopy; all the biological samples were also subjected to vibration magnetometry. Since the upper airways are the first part of the respiratory tract, which is exposed to inhaled particles, it can be assumed that inhaled particles may be partially deposited in this region. Scanning electron microscopy revealed the presence of metal-based solid particles/clusters in the majority of the analysed cytological mucus samples and also in hypertrophic tissues; in all groups, the particles were of submicron size. Raman microspectroscopy detected the presence of particles/clusters based on amorphous carbon, graphite, calcium carbonate, anatase and barite only in the hypertrophic tissue. The obtained results show that the composition of some of the solid particles (i.e. Ba, Zn, Fe and Ti) detected in the mucus from the surface of the hypertrophic tissues resembled the particles found in the hypertrophic tissue itself. It can be assumed that after the capture of the inhaled particles by the mucus, they penetrate into the deeper layers of tissue.
Multimodal gadolinium fluoride nanoparticles belong to potential contrast agents useful for bimodal optical fluorescence and magnetic resonance imaging. However, the metallic nature of the nanoparticles, similarly to some paramagnetic iron oxides, might induce allergic and anaphylactic reactions in patients after administration. A reduction of these adverse side effects is a priority for the safe application of the nanoparticles. Herein, we prepared paramagnetic poly(4-styrenesulfonic acid-co-maleic acid) (PSSMA)-stabilized GdF3 nanoparticles with surface modified by Atto 488-labeled poly(styrene-grad-2-dimethylaminoethyl acrylate)-block-poly(2-dimethylaminoethyl acrylate) (PSDA-A488) with reactive amino groups for introduction of an additional imaging (luminescence) modality and possible targeting of anticancer drugs. The saturation magnetization of GdF3@PSSMA particles according to SQUID magnetometry reached 157 Am2 kg-1 at 2 K and magnetic field of 7 T. GdF3@PSSMA-PSDA-A488 nanoparticles were well tolerated by human cervical adenocarcinoma (HeLa), mouse bone marrow-derived mast cells (BMMC), and rat basophilic mast cells (RBL-2H3); the particles also affected cell morphology and protein tyrosine phosphorylation in mast cells. Moreover, the nanoparticles interfered with the activation of mast cells by multivalent antigens and inhibited calcium mobilization and cell degranulation. These findings show that the new multimodal GdF3-based nanoparticles possess properties useful for various imaging methods and might minimize mast cell degranulation incurred after future nanoparticle diagnostic administration.
- MeSH
- degranulace buněk MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- mastocyty * MeSH
- myši MeSH
- nanočástice * MeSH
- polymery MeSH
- růstový diferenciační faktor 3 MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: The aim was to design and thoroughly characterize monodisperse Fe3O4@SiO2-Ag nanoparticles with strong antibacterial properties, which makes them a candidate for targeting bacterial infections. METHODS: The monodisperse Fe3O4 nanoparticles were prepared by oleic acid-stabilized thermal decomposition of Fe(III) oleate; the particles were coated with silica shell using a water-in-oil reverse microemulsion, involving hydrolysis and condensation of tetramethyl orthosilicate. Resulting Fe3O4@SiO2 particles were modified by (3-mercaptopropyl)trimethoxysilane to introduce 1.1 mmol SH/g. Finally, the Fe3O4@SiO2-SH nanoparticles were decorated with silver nanoclusters formed by reduction of silver nitrate with NaBH4. The particles were analyzed by FTIR, X-ray photoelectron and atomic absorption spectroscopy, dynamic light scattering and vibrating sample magnetometry. The antibacterial activity of the Fe3O4@SiO2 and Fe3O4@SiO2-Ag nanoparticles was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria cultivated on Luria agar plates or in Luria broth. RESULTS: The superparamagnetic Fe3O4@SiO2-Ag nanoparticles (21 nm in diameter; saturation magnetization 26 A∙m2/kg) were successfully obtained and characterized. Inhibitory and toxic effects against bacteria were documented by incubation of the Fe3O4@SiO2-Ag nanoparticles with Staphylococcus aureus and Escherichia coli. CONCLUSIONS: The combination of magnetic properties together with bactericidal effects is suitable for the disinfection of medical instruments, water purification, food packaging, etc.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- Escherichia coli účinky léků MeSH
- kyselina olejová chemie MeSH
- magnetické nanočástice chemie MeSH
- oxid křemičitý chemie MeSH
- povrchové vlastnosti MeSH
- silany chemie MeSH
- Staphylococcus aureus účinky léků MeSH
- stříbro chemie farmakologie MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
Monodisperse nonmagnetic macroporous poly(glycidyl methacrylate) (PGMA) microspheres were synthesized by multistep swelling polymerization of glycidyl methacrylate, ethylene dimethacrylate and 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA). This was followed (a) by ammonolysis to modify the microspheres with amino groups, and (b) by incorporation of iron oxide (γ-Fe2O3) into the pores to render the particles magnetic. The resulting porous and magnetic microspheres were characterized by scanning and transmission electron microscopy (SEM and TEM), atomic absorption and Fourier transform infrared spectroscopy (AAS and FTIR), elemental analysis, vibrating magnetometry, mercury porosimetry and Brunauer-Emmett-Teller adsorption/desorption isotherms. The microspheres are meso- and macroporous, typically 5 μm in diameter, contain 0.9 mM · g-1 of amino groups and 14 wt.% of iron according to elemental analysis and AAS, respectively. The particles were conjugated to p46/Myo1C protein, a potential biomarker of autoimmune diseases, to isolate specific autoantibodies in the blood of patients suffering from multiple sclerosis (MS). The p46/Myo1C loaded microspheres are shown to enable the preconcentration of minute quantities of specific immunoglobulins prior to their quantification via SDS-PAGE. The immunoglobulin M (IgM) with affinity to Myo1C was detected in MS patients. Graphical abstract Monodisperse magnetic poly(glycidyl methacrylate) microspheres were synthesized, conjugated with 46 kDa form of unconventional Myo1C protein (p46/Myo1C) via carbodiimide (DIC) chemistry, and specific autoantibodies isolated from blood of multiple sclerosis (MS) patients; immunoglobulin M (IgM) level increased in MS patients.
- MeSH
- autoimunitní nemoci imunologie MeSH
- autoprotilátky krev chemie imunologie izolace a purifikace MeSH
- kyseliny polymethakrylové chemie MeSH
- lidé MeSH
- magnety chemie MeSH
- mikrosféry * MeSH
- molekulová hmotnost MeSH
- myosin typu I chemie imunologie MeSH
- roztroušená skleróza imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
