Príspevok sa venuje analýze rôznych frakcií aerosólu vrátane nanometrických, mikrometrických častíc a PM "particulate matter" častíc v pracovnom ovzduší. Z výsledkov vyplýva, že analýzou veľkostnej distribúcie častíc pri výrobe oceľových rúr valcovaním za tepla, konkrétne pri dierovacom lise, sa preukázala prítomnosť PM častíc s rozmermi menšími ako 0,5 μm (7,1 μg/m3), ako 1 μm (16,4 μg/m3), ako 2,5 μm (40,4 μg/m3), ako 4,0 μm (58,6 μg/m3) a ako 10 μm (95,1 μg/m3). Ďalej sme výsledky vyhodnocovali ako veľkostnú distribúciu častíc podľa ich početnosti. Z celkového počtu častíc v odobratom objeme vzduchu 4,90⋅105 bolo 4,13⋅105 nanočastíc (84,4 %). Na druhom pracovisku – pri tŕňovej tyči – sme analyzovali podobne PM častice. Výsledky preukázali prítomnosť PM0,5 (2,8 μg/m3), PM1,0 (3,9 μg/m3), PM2,5 (15,5 μg/m3) a PM10 (119,9 μg/m3). V odobratom objeme vzduchu bolo z celkového počtu 5,75⋅105 častíc 5,29⋅105 nanočastíc (92,1 %). Z nameraných hodnôt vyplýva, že je dôležité objektivizovať častice v pracovnom ovzduší aj v nanorozmeroch a mikrorozmeroch, pretože môžu predstavovať potenciálne riziko poškodenia zdravia.
The article deals with the analysis of various aerosol fractions, including nanometric, micrometric particles and particulate matter (PM), in the working atmosphere. Analysis of particle distribution in the production of steel tubes by hot rolling, precisely at the punching press has been shown the presence of PM particles with diameter less than 0.5 μm (7.1 μg/m3), 1 μm (16.4 μg/m3), 2.5 μm (40.4 μg/m3), less than 4.0 μm (58.6 μg/m3) and less than 10 μm (95.1 μg/m3). We further evaluated the results of particle size distribution according to their quantity. We have analysed of the total number of particles in the withdrawn air volume of 4.90⋅105. The results showed that 84.4% (4.13⋅105) of the total number of particles is in the range of nanometres. In the another workplace with the thorn rods production, the results showed the presence of PM0.5 (2.8 μg/m3), PM1.0 (3.9 μg/m3), PM2.5 (15.5 μg/m3) and PM10 (119.9 μg/m3). The total number of particles in the nanometre range was 5.29⋅105 (92.1%). The total number of particles of this analysis of the air was 5.75⋅105. From the measured values, it is important to objectify the particles in the working atmosphere even in nano and micro dimensions, as they may pose a potential risk of damage to health.
This work deals with the mechanical characterization by depth-sensing indentation (DSI) of PLLA and PLDA composites reinforced with micro-particles of Mg (up to 15wt%), which is a challenging task since the indented volume must provide information of the bulk composite, i.e. contain enough reinforcement particles. The composites were fabricated by combining hot extrusion and compression moulding. Physico-chemical characterization by TGA and DSC indicates that Mg anticipates the thermal degradation of the polymers but does not compromise their stability during processing. Especial emphasis is devoted to determine the effect of strain rate and Mg content on mechanical behavior, thus important information about the visco-elastic behavior and time-dependent response of the composites is obtained. Relevant for the intended application is that Mg addition increases the elastic modulus and hardness of the polymeric matrices and induces a higher resistance to flow. The elastic modulus obtained by DSI experiments shows good agreement with that obtained by uniaxial compression tests. The results indicate that DSI experiments are a reliable method to calculate the modulus of polymeric composites reinforced with micro-particles. Taking into consideration the mechanical properties results, PLA/Mg composite could be used as substitute for biodegradable monolithic polymeric implants already in the market for orthopedics (freeform meshes, mini plates, screws, pins, …), craniomaxillofacial, or spine.
BACKGROUND: Nanotechnology is receiving enormous funding. Very little however is known about the health dangers of this technology so far. Chronic tonsillitis is one of a number of diseases called idiopathic. Among other factors, the tonsils are exposed to suspended particles in inhaled air including nano particles. The objective of this study was to detect and evaluate metallic particles in human tonsil tissue diagnosed with chronic tonsillitis and in amniotic fluid as a comparison. METHODS: . Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) was used for identification of solid particles in a total of 64 samples of routinely analyzed biopsy and cytologic material. RESULTS: Almost all samples were found to contain solid particles of various metals. The most frequent, regardless of diagnosis, were iron, chromium, nickel and aluminium. The size, determined using SEM, varied from around 500 nm to 25 µm. The majority formed aggregates of several micrometers in size but there were a significant number of smaller (sub-micrometer or nano-sized) particles present. The incidence of metallic particles was similar in child and adult tissues. The difference was in composition: the presence of several metals in adults was due to occupational exposure. CONCLUSIONS: The presence of metallic particles in pathologically altered tissues may signal an alternative causation of some diseases. The ethiopathogenic explanation of these diseases associated with the presence of nano-sized particles in the organism has emerged into a new field of pathology, nanopathology.
- MeSH
- Biopsy methods MeSH
- Adult MeSH
- Palatine Tonsil pathology MeSH
- Humans MeSH
- Microscopy, Electron, Scanning MeSH
- Pilot Projects MeSH
- Amniotic Fluid cytology MeSH
- Reproducibility of Results MeSH
- Spectrometry, X-Ray Emission MeSH
- Tonsillitis diagnosis MeSH
- Particle Size * MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The paper addresses the wear particles released from commercially available "low-metallic" automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (< 100 nm) were by three orders of magnitude larger when compared to the microparticles. A significant release of nanoparticles was measured when the average temperature of the rotor reached 300°C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles.
OBJECTIVE: The aim of this prospective study is to evaluate presence and quantity of micro- and nanosized particles (NPs) and interindividual differences in their distribution and composition in nasal mucosa. METHODS: Six samples of nasal mucosa obtained by mucotomy from patients with chronic hypertrophic rhinosinusitis were examined. Samples divided into 4 parts according to the distance from the nostrils were analyzed by scanning electron microscopy and Raman microspectroscopy to detect solid particles and characterize their morphology and composition. A novel method of quantification of the particles was designed and used to evaluate interindividual differences in distribution of the particles. The findings were compared with patients' employment history. RESULTS: In all the samples, NPs of different elemental composition were found (iron, barium, copper, titanium, etc.), predominantly in the parts most distant from nostrils, in various depths from the surface of the mucosa and interindividual differences in their quantity and composition were found, possibly in relation to professional exposition. CONCLUSIONS: This study has proven the possibility of quantification of distribution of micro- and nanosized particles in tissue samples and that the NPs may deposit in deeper layers of mucosa and their elemental composition may be related to professional exposition to the sources of NPs.
- MeSH
- Adult MeSH
- Metal Nanoparticles * MeSH
- Middle Aged MeSH
- Humans MeSH
- Microscopy, Electron, Scanning MeSH
- Nasal Mucosa pathology MeSH
- Pilot Projects MeSH
- Aged MeSH
- Sinusitis pathology MeSH
- Titanium isolation & purification metabolism MeSH
- Particle Size MeSH
- Iron isolation & purification metabolism MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Assessment of the impact that air contaminants have on health is difficult as this is a complex mixture of substances that varies depending on the time and place. There are many studies on the association between air pollution and increased morbidity and mortality. Before the effect of polluted air is manifested at the level of the organs, an impact can be observed at the molecular level. These include some new biomarkers, like a shortening of the mean telomere length in DNA, dysregulation of gene expression caused by microRNA levels or a variation in the copy number of mitochondrial DNA. These changes may predispose individuals to premature development of age-related diseases and consequently to shortening of life. The common attribute, shared by changes at the molecular level and the development of diseases, is the presence of oxidative stress.
- MeSH
- Air Pollutants * analysis toxicity MeSH
- Humans MeSH
- MicroRNAs * MeSH
- Particulate Matter analysis MeSH
- Aging MeSH
- Air Pollution * adverse effects analysis MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
A new type of promising chitosan beads with advanced properties were obtained under microwave radiation according to Green Chemistry principles. Biomaterials were prepared using chitosan as raw material and glutamic acid/1,5-pentanodiol mixture as crosslinking agents. Additionally beads were modified with Tilia platyphyllos extract to enhance their antioxidant properties. Beads were investigated over their chemical structure by FT-IR analysis. Also their morphology has been investigated by SEM method. Additionally swelling capacity of the obtained hydrogels was determined. Lack of cytotoxicity has been confirmed by MTT assay. Proliferation studies were carried out on L929 mouse fibroblasts. Advanced properties of the obtained beads were investigated by studying pH sensitivity and antioxidant properties by DPPH method. Also susceptibility to degradation and biodegradation by Sturm Test method was evaluated. Results shows that proposed chitosan beads and their eco-friendly synthesis method can be applied in cell therapy and tissue engineering.
- MeSH
- Antioxidants pharmacology MeSH
- Biocompatible Materials pharmacology MeSH
- Cell Culture Techniques methods MeSH
- Chitosan chemistry MeSH
- Hydrogen-Ion Concentration MeSH
- Humans MeSH
- Microspheres * MeSH
- Microwaves * MeSH
- Mice MeSH
- Cell Proliferation drug effects MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Production of particles and their adaptation in the pharmacology became an object of interest, and they are the currently introduced therapies based on the use of micro and nanoparticles. The use of gold particles is not an exception. This review has focused on the application of gold micro and nanoparticles in pharmacology and biomedicine. The particles can be used for diagnosis respective theranostic of cancer, rheumatoid arthritis and as antimicrobial means. Besides these applications, specifications of gold, gold particles, and colloidal gold manufacturing and their comparison with the solid gold, are described as well. This review is based on a survey of actual scientific literature.
- MeSH
- Anti-Inflammatory Agents chemistry pharmacology MeSH
- Anti-Infective Agents chemistry pharmacology MeSH
- Bacteria drug effects MeSH
- Biomedical Research MeSH
- Fungi drug effects MeSH
- Humans MeSH
- Neoplasms diagnosis drug therapy MeSH
- Nanoparticles chemistry MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- Arthritis, Rheumatoid diagnosis drug therapy MeSH
- Gold chemistry pharmacology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
In this paper, the treatment of poly-ε-caprolactone (PCL) nano/micro-mesh system by cryogenic grinding and subsequent characterization of obtained product is described. The PCL nano/micro-mesh layer submerged in appropriate liquid was cryogenically ground and obtained particles were characterized employing mainly laser diffraction and scanning electron microscopy (SEM). In the ground sample, different types of particles (fibrous particles, fibrous fragments, agglomerates with and without an internal fibrous structure, lamellae and nanoparticles) were identified, described and quantified. Parameters of cryogenic grinding (weight of sample, type of liquid medium, and influence of sample storage) were optimized to maximize the yield of particles with desired features. The potential of the system for cell scaffolding was demonstrated by cultivation of 3T3 fibroblasts on the produced microparticles.
- MeSH
- Cell Adhesion drug effects MeSH
- Cell Line MeSH
- 3T3 Cells MeSH
- Fibroblasts drug effects MeSH
- Microscopy, Electron, Scanning methods MeSH
- Mice MeSH
- Nanoparticles chemistry MeSH
- Polyesters chemistry pharmacology MeSH
- Cell Proliferation drug effects MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
