Koncem první poloviny 90. letech minulého století se objevil v rinochirurgii nový nástroj, který se v dalších letech rychle rozšířil na pracoviště provádějící rinochirurgické operace technikou funkční endoskopické chirurgie. Jde o systém dvou dutých, do sebe zasunutých nožů, z nichž vnitřní se otáčí. Dutina nožů je spojena s odsávačem. Vlivem podtlaku se při otevření okna systému nasávají měkké tkáně, které jsou rotujícím nožem odděleny a transportovány směrem k odsávači. Nástroj nazývaný shaver nebo mikrodebridor je určen převážně k ablaci měkkých tkání, v rinochirurgii – polypů, hypertrofické sliznice, nádorů, méně vhodný je pro odstraňování kostěných struktur. Postupným vývojem konstrukce nožů pro shaver se rozšířily indikace pro jejich aplikaci – pro agresivní zásah, nebo naopak pro jemnou ablaci. Zvláštní nože umožňují resekci určitých struktur (nůž pro uncinektomii), nebo přispívají k bezpečnosti operačního postupu (nůž pro etmoidektomii chráněný směrem dozadu). Kostěné struktury umožňují operovat shaver – frézy různého tvaru. Podle určení – kulovitý tvar pro sfenoidotomii nebo etmoidektomii, zahnutý podélný pro trepanace v okolí vývodu čelní dutiny atd. Pro účinnost shaveru jsou nejdůležitější dva faktory – podtlak vytvářený odsávačkou a ostrost nožů nebo frézy. Počet otáček není až tak významný. Pro ablaci měkkých tkání je nejúčinnější oscilační pracovní modus, pro frézování rotační. V současné době se na trhu nabízí řada shaverů, v práci je porovnáváno pět různých systémů nabízených firmami. V posledních letech se šíře nabídky jednotlivých firem začíná přibližovat, vývoj stále pokračuje. V souvislosti s endoskopickou endonazální chirurgii je shaver užitečným nástrojem i proto, že vlastně v sobě integruje dva nástroje v jednom – odsávač a nůž k odstranění tkání. Tím do značné míry eliminuje „jednorukost“ s endoskopem operujícího chirurga. Agresivita shaveru vyžaduje nácvik, aby operování s ním bylo bezpečné a nekomplikované. Po zvládnutí operační techniky lze shaverem vykonávat velice šetrné zásahy jako jsou například ablace povrchních vrstev ztluštělé sliznice při šetření bazální vrstvy, je možné vytvářet malé antrostomie, prakticky v rozsahu přirozeného primárního ostia čelistní dutiny (small hall technique). Výkony se stávají ještě méně invazivní než klasickým instrumentáriem pro funkční endonazální chirurgii co do vztahu ke strukturám, které mají být uchovány a na druhé straně radikální a exaktnější při odstraňování patologie. Nové konstrukce zahnutých nožů a fréz zvyšují dostupnost patologických změn v paranazálních dutinách, které mohou být za endoskopické kontroly endonazálně odstraněny. Takto lze ještě lépe naplnit koncepci funkční endonazální chirurgie, pokud jde o léčbu rinosinusitid. U operací, které nejsou zaměřeny na záněty, ale využívají endoskopického instrumentária a endonazálního přístupu, shaver rozšiřuje možnosti a zvyšují komfort operatéra; sem patří operace slzných cest (DCRS), dekomprese očnice a zrakového nervu, operace lební spodiny, operace v nosohltanu a další. Stále se nacházejí nové možnosti aplikace shaverů a také konstrukce nových systémů a inovace starších dokazují, že zmíněný nástroj a operační technika se dále dynamicky vyvíjejí. Nikoli bezvýznamnou skutečností je fakt, že shaver v instrumentáriu pro funkční endonazální chirurgii nahrazuje řadu nástrojů a jiné vhodně doplňuje. Zajímavé je použití shaveru v mikrolaryngochirurgii, kde čeká na větší rozšíření, dále při rinoplastikách, k redukci lymfoepiteliální tkáně patrových tonzil (intrakapsulární tonzilotomie).

In the end of 90ties of the last century a new tool appeared in rhino surgery and rapidly spread out to workplaces performing rhino surgery operations by the technique of functional endoscopic surgery. It is a system of two hollow knives, one inserted into the other, while the inner one rotates inside the other. The cavity of the knives is connected with an exhauster. Due to the suction opening of the window follows to sucking of soft tissues, which are detached by the rotating knife and transported to the exhauster. The tool called shaver or microdebrider is mostly used for ablation of soft tissues, the application in rhino surgery being for polyps, hypertrophic mucosa, tumors, less suitable for the removal of osseous structures. The gradual development of the construction of knives of the shaver extended the indications to their application for aggressive intervention or, conversely, to fine ablation. Special knives enable resection of certain structures (a knife for uncinectomy) or contribute to safety of surgical procedure *a knife for ethmoidectomy protected toward the rear). The bone structures can be operated on by shaver- milling machine of various shapes. The purpose determines the properties – a spherical shape for sphenoidotomy or ethmoidectomy, a bent longitudinal for trepanation in the area of the outlet of frontal cavity etc. Two factors are most important for efficiency of the shaver – negative pressure created by the exhauster and sharpness of the knives or milling machine. The revolutions (per minute) are not so important. For the ablation of soft tissues the oscillation working modus proved to be most efficient, and the rotation modus for the milling. There are presently various kinds of shavers on the market and the paper compares five different systems provided by different companies. The supply offered by different companies in the last years has become similar, but the development continues. In connection with endoscopic endonasal surgery the shaver proved to be a useful tool also for the fact that it integrates two tools in one – the exhauster and the knife for removal of the tissues. This property eliminates one-handedness of the surgeon operating on with the use of endoscope. The aggressiveness of the shaver requires practice in order to make the surgery safe and non-complicated. After mastering of the operation technique the surgeon can perform very fine and considerate interventions such as ablation of superficial layers of thickened (incrassate) mucosa for preservation of basal layer, it is possible to form small anthrostomy virtually in the range of natural primary ostium of maxillary cavity (small hall technique). The interventions have become even less invasive than with the application of classical instruments for functional endonasal surgery as far as the structures which should be saved are concerned, and may be radical and more exact in removing pathological tissues. New constructions of bent knives and milling machines increase availability of pathological changes in paranasal cavities, which may removed from endonasal approach under endoscopic control. This approach can even better fulfill the concept of endonasal surgery as far as the treatment of rhinosinusitis is concerned. In operations which are not directed to treatment of inflammation, but make use of endoscopic instruments and endonasal approach, the shaver extends the possibilities and improves the comfort of the surgeon. These interventions include operations on lacrimation pathways (DCRS) decompression of eye socket and visual nerve, operation on cranium base, operation on nasopharynx, etc. There are ever emerging possibilities for the application of shavers as well as construction of new systems and innovation of older ones which demonstrate that the tools and the operation techniques are still in a state of dynamic evolution. It is also of considerable importance that the shaver substitutes various other tools in endonasal surgery and supplements the other in a suitable way. The application of shavers in microlaryngosurgery is of interest and awaits more extensive usage as well as in rhinoplasty, reduction of lymphoepithelial tissue of palatinal tonsils (intracapsular tonsillectomy).

• MeSH
• dakryocystorinostomie metody   trendy   MeSH
• endoskopie metody   MeSH
• lidé MeSH
• nosní polypy chirurgie   MeSH
• nosní skořepy chirurgie   MeSH
• odsávání přístrojové vybavení   MeSH
• otorinolaryngologické chirurgické výkony metody   přístrojové vybavení   MeSH
• rýma chirurgie   terapie   MeSH
• sinusitida chirurgie   terapie   MeSH
• Check Tag
• lidé MeSH
• Geografické názvy
• Česká republika MeSH

At present, new acrylic plastic technologies are being developed in dentistry. Although this kind of material has been used for dental prostheses for over 80 years, it has been produced in the form of disks with the computer-aided design/computer-aided manufacturing (CAD/CAM) technology for over 15 years. The purpose of the article was to collect information from the literature on acrylic materials processed through the milling technology (CAD/CAM). The publicly available databases PubMed, Google Scholar and Scopus were searched using the key word "acrylic resins, CAD/CAM". All articles describing the application and testing of CAD/CAM disks were selected. Duplicate articles were removed. More than 100 articles that described the use of materials machined using the milling equipment were found. These included works comparing the mechanical properties, biocompatibility and clinical use of the materials. After the initial selection, 36 papers on this subject were included in this review. The number of studies on the processing of acrylic materials with the use of the CAD/CAM technology has been increasing worldwide. Since such materials have better mechanical properties, no polymerization shrinkage occurs during processing, the amount of residual monomer material is very low and they have better color stability than self-curing materials.

• MeSH
• akrylové pryskyřice * MeSH
• design s pomocí počítače MeSH
• lidé MeSH
• polymethylmethakrylát MeSH
• testování materiálů MeSH
• zubní materiály * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• systematický přehled MeSH

Nanocrystals have received considerable attention in dermal application due to their ability to enhance delivery to the skin and overcome bioavailability issues caused by poor water and oil drug solubility. The objective of this study was to investigate the effect of nanocrystals on the mechanism of penetration behavior of curcumin as a model drug. Curcumin nanocrystals were produced by the smartCrystals® process, i.e. bead milling followed by high pressure homogenization. The mean particle size of the curcumin crystals was about 200nm. Stabilization was performed with alkyl polyglycoside surfactants. The distribution of curcumin within the skin was determined in vitro on cross-sections of porcine skin and visualized by fluorescent microscopy. The skin penetration profile was analyzed for the curcumin nanosuspension with decreasing concentrations (2%, 0.2%, 0.02% and 0.002% by weight) and compared to nanocrystals in a viscous hydroxypropylcellulose (HPC) gel. This study demonstrated there was minor difference between low viscous nanosuspension and the gel, but low viscosity seemed to favor skin penetration. Localization of curcumin was observed in the hair follicles, also contributing to skin uptake. Looking at the penetration of curcumin from formulations with decreasing nanocrystal concentration, formulations with 2%, 0.2% and 0.02% showed a similar penetration profile, whereas a significantly weaker fluorescence was observed in the case of a formulation containing 0.002% of curcumin nanocrystals. In this study we have shown that curcumin nanocrystals prepared by the smartCrystal® process are promising carriers in dermal application and furthermore, we identified the ideal concentration of 0.02% nanocrystals in dermal formulations. The comprehensive study of decreasing curcumin concentration in formulations revealed that the saturation solubility (Cs) is not the only determining factor for the penetration. A new mechanism based also on the concentration of the nanocrystals on skin surface was proposed.

• MeSH
• kožní absorpce * MeSH
• kurkumin aplikace a dávkování   MeSH
• mikroskopie elektronová rastrovací MeSH
• nanočástice * MeSH
• teoretické modely * MeSH
• Publikační typ
• časopisecké články MeSH

A novel approach of surface treatment of orthopaedic implants combining electric discharge machining (EDM), chemical milling (etching) and shot peening is presented in this study. Each of the three techniques have been used or proposed to be used as a favourable surface treatment of biomedical titanium alloys. But to our knowledge, the three techniques have not yet been used in combination. Surface morphology and chemistry were studied by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Fatigue life of the material was determined and finally several in-vitro biocompatibility tests have been performed. EDM and subsequent chemical milling leads to a significant improvement of osteoblast proliferation and viability thanks to favourable surface morphology and increased oxygen content on the surface. Subsequent shot-peening significantly improves the fatigue endurance of the material. Material after proposed combined surface treatment possesses favourable mechanical properties and enhanced osteoblast proliferation. EDM treatment and EDM with shot peening also supported early osteogenic cell differentiation, manifested by a higher expression of collagen type I. The combined surface treatment is therefore promising for a range of applications in orthopaedics.

• MeSH
• biokompatibilní materiály chemie   MeSH
• buněčná adheze účinky léků   MeSH
• buněčná diferenciace účinky léků   MeSH
• fluorescenční protilátková technika MeSH
• fotoelektronová spektroskopie MeSH
• lidé MeSH
• mikroskopie elektronová rastrovací MeSH
• nádorové buněčné linie MeSH
• osteoblasty cytologie   účinky léků   MeSH
• povrchové vlastnosti MeSH
• proliferace buněk účinky léků   MeSH
• protézy a implantáty MeSH
• titan chemie   farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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.

• MeSH
• Aspergillus fumigatus účinky léků   enzymologie   MeSH
• buněčná stěna účinky léků   MeSH
• buněčné extrakty chemie   MeSH
• detergenty farmakologie   MeSH
• fungální proteiny analýza   metabolismus   MeSH
• glukosa-6-fosfátdehydrogenasa analýza   metabolismus   MeSH
• osmotický tlak MeSH
• Penicillium účinky léků   enzymologie   MeSH
• Rhodotorula účinky léků   enzymologie   MeSH
• vibrace ultrazvukové MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Although methods exist to readily determine the particle size distribution (PSD) of an active pharmaceutical ingredient (API) before its formulation into a final product, the primary challenge is to develop a method to determine the PSD of APIs in a finished tablet. To address the limitations of existing PSD methods, we used hot-stage microscopy to observe tablet disintegration during temperature change and, thus, reveal the API particles in a tablet. Both mechanical and liquid disintegration were evaluated after we had identified optimum milling time for mechanical disintegration and optimum volume of water for liquid disintegration. In each case, hot-stage micrographs, taken before and after the API melting point, were compared with image analysis software to obtain the PSDs. Then, the PSDs of the APIs from the disintegrated tablets were compared with the PSDs of raw APIs. Good agreement was obtained, thereby confirming the robustness of our methodology. The availability of such a method equips pharmaceutical scientists with an in vitro assessment method that will more reliably determine the PSD of active substances in finished tablets.

• MeSH
• farmaceutická chemie * MeSH
• lidé MeSH
• mikroskopie MeSH
• tablety chemie   terapeutické užití   MeSH
• teplota MeSH
• velikost částic MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Wood chips ash coming from biomass heating plant is studied as an eco-friendly mineral admixture in mortar mix design. The raw material was mechanically activated by milling in a vibratory disc mill to a degree of fineness comparable to cement. For the mortars with ash dosage, basic physical, mechanical, hygric, and thermal properties is accessed. The mortars with partial Portland cement replacement with wood chips ash exhibited good functional properties for all studied ash dosages. With increasing amount of the ash used, the average pore diameter decreased due to the partial filler effect of WCHA in mortar mix. The strength activity index was very high for all studied mortars and gave evidence of the wood chips ash pozzolanity. The pozzolan effectiveness coefficient varied from 1.52 to 0.59, which proved the pozzolanity of the studied ash and synergic effects in the Portland cement-ash-water system. The results of leaching tests showed, the chlorides contained in ash were safely immobilized in the silicate matrix. The environmental evaluation revealed decrease in both carbon dioxide production and energy consumption by the use of wood chips ash in mortar mix. For the mortar with 20% substitution of Portland cement with wood chips ash, it represents 15% of CO2 and 16% of energy, as compared with the reference mortar mix. As the developed mortars possess good functional and environmental parameters the analyzed wood chips ash can be considered as an eco-efficient low-cost alternative to other pozzolans for production of blended binders.

• MeSH
• biomasa MeSH
• dřevo * MeSH
• konstrukční materiály MeSH
• minerály MeSH
• popel uhelný * MeSH
• Publikační typ
• časopisecké články MeSH

TiO2 is the most studied photocatalyst because of its non-toxicity, chemical stability, and low cost. However, the problem of TiO2 is its low activity in the visible region of the spectrum. In this study, we focused on the preparation of composite photocatalytic materials with altered light absorption properties. TiO2 P25 and various metal oxides were mechanically joined by ball-milling and immobilized on glass plates. The prepared samples were evaluated based on their ability to degrade NO in gas phase. The formation of undesirable byproducts was also investigated. Four best performing composites were later chosen, characterized, and further evaluated under various conditions. According to their performance, the metal oxide additives can be divided into three groups. P25/Fe2O3 showed the most promising results-an increase in overall deNOx activity under modified ISO conditions and altered selectivity (less NO2 is formed) under both simulated outdoor and simulated indoor conditions. On the other hand, P25/V2O5 composite showed negligible photocatalytic activity. The intermediate group includes P25/WO3 and P25/ZnO photocatalysts, whose performances are similar to those of pristine P25.

• MeSH
• katalýza MeSH
• oxidy * MeSH
• titan * chemie   MeSH
• Publikační typ
• časopisecké články MeSH

The ecotoxicological effect of after-usage released TiO2 nanoparticles in aquatic resources has been a major concern owing to their production and utilization in different applications. Addressing the issue, this study investigates the detailed in vivo molecular toxicity of TiO2 nanoparticles with Paramecium caudatum. TiO2 nanoparticles were synthesized at a lab scale using high energy ball milling technique; characterized for their physicochemical properties and investigated for their ecotoxicological impact on oxidative stress, steatosis, and apoptosis of cells through different biochemical analysis, flow cytometry, and fluorescent microscopy. TiO2 nanoparticles; TiO2 (N15); of size 36 ± 12 nm were synthesized with a zeta potential of - 20.2 ± 8.8 mV and bandgap of 4.6 ± 0.3 eV and exhibited a blue shift in UV-spectrum. Compared to the Bulk TiO2, the TiO2 (N15) exhibited higher cytotoxicity with a 24 h LC50 of 202.4 μg/ml with P. Caudatum. The mechanism was elucidated as the size and charge-dependent internalization of nanoparticles leading to abnormal physiological metabolism in oxidative stress, steatosis, and apoptosis because of their influential effect on the activity of metabolic proteins like SOD, GSH, MDA, and catalase. The study emphasized the controlled usage TiO2 nanoparticles in daily activity with a concern for ecological and biomedical aspects.

• MeSH
• apoptóza MeSH
• nanočástice * chemie   toxicita   MeSH
• oxidační stres MeSH
• Paramecium caudatum * MeSH
• titan toxicita   MeSH
• Publikační typ
• časopisecké články MeSH

Three polysaccharide complexes (PSCs) were isolated from the aerial parts of common purslane (Portulaca oleracea L.), and the flowers of common lavender (Lavandula angustifolia Mill.) and silver linden (Tilia tomentosa Moench) by boiling water extraction and ethanol precipitation. The chemical composition and immunomodulating effects of isolated PSCs were characterized. The chemical characterization revealed that the three samples contain mainly pectic polysaccharides. They exhibited ex vivo intestinal immunomodulating activity through the murine Peyer's patch-mediated bone marrow cell proliferation test at 100μg/ml concentration. At the same time, they stimulated ex vivo human blood T-cell populations (CD4+/CD25+ and CD8+/CD25+), phagocytic leukocytes (CD14+ and CD64+ cells) and induced IL-6 production from human white blood cells and Peyer's patch cells. The herbal PSCs stimulated ex vivo ROS production from whole blood phagocytes and showed unspecific in vitro anti-proliferative activity against normal and A549, HeLa and LS180 tumor cells. This is the first report on immunomodulating studies of linden flower pectins and chemical and biological activity characterization of lavender polysaccharides. Our study demonstrates that similarly to purslane, lavender and silver linden herbal materials contain immunomodulating polysaccharides that could be useful for support of compromised immune system.

• MeSH
• adaptivní imunita účinky léků   MeSH
• imunomodulace účinky léků   MeSH
• koncentrace vodíkových iontů MeSH
• levandule chemie   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• pektiny chemie   MeSH
• Peyerovy pláty účinky léků   imunologie   MeSH
• polysacharidy chemie   farmakologie   MeSH
• Portulaca chemie   MeSH
• přirozená imunita účinky léků   MeSH
• protinádorové látky chemie   farmakologie   MeSH
• Tilia chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH