A study of new pig manure treatment and filtration process was carried out. The advantage of the worked out technology is the method of incorporation of crystalline phase into solid organic part of manure. The obtained new solid phase of manure contains about 50% of crystalline phase forming a filtration aid that enables high effectiveness of manure filtration. The filtration rate of manure separation into solid and liquid fractions with pressure filter may achieve 1300-3000 kg/m(2)/h. The method makes it possible to maintain an overall average pollutant removal performance 90% for the chemical oxygen demand COD, > 99% for the suspended solids SS, to 47% for the total nitrogen content. The obtained results showed that the proposed technology being efficient and simple offers a possible solution to pig manure problems.

• MeSH
• anaerobióza MeSH
• filtrace * MeSH
• hnůj * MeSH
• prasata MeSH
• průmyslová hnojiva * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hnůj * MeSH
• průmyslová hnojiva * MeSH

In the new century, electrospun nanofibrous webs are widely employed in various applications due to their specific surface area and porous structure with narrow pore size. The mechanical properties have a major influence on the applications of nanofiber webs. Lamination technology is an important method for improving the mechanical strength of nanofiber webs. In this study, the influence of laminating pressure on the properties of polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) nanofibers/laminate was investigated. Heat-press lamination was carried out at three different pressures, and the surface morphologies of the multilayer nanofibrous membranes were observed under an optical microscope. In addition, air permeability, water filtration, and contact angle experiments were performed to examine the effect of laminating pressure on the breathability, water permeability and surface wettability of multilayer nanofibrous membranes. A bursting strength test was developed and applied to measure the maximum bursting pressure of the nanofibers from the laminated surface. A water filtration test was performed using a cross-flow unit. Based on the results of the tests, the optimum laminating pressure was determined for both PAN and PVDF multilayer nanofibrous membranes to prepare suitable microfilters for liquid filtration.

• Klíčová slova
• lamination, nanofiber, water filtration,
• Publikační typ
• časopisecké články MeSH

A mathematical model of synovial film filtration and synovial gel formation at normal approach of cartilage surfaces in the human hip joint is presented. The biphasic mixture model presented in Part I of this paper [Hlavácek, J. Biomechanics 26, (1993)] for synovial fluid and that of Mow and his collaborators [J. Biomech. Engng 102, 73-84 (1980)] for cartilage are used. A general analysis of filtration of an axially symmetric synovial squeeze-film between two cartilage layers at normal approach is given. The geometrically simple case much idealising the human hip joint is also considered: two cartilage discs with a synovial film in between are compressed by the steady loading of the half human weight. The homogeneous film filtration process where the synovial gap remains parallel and the macromolecular concentration in the gap is spatial homogeneous (to the thin-film approximation) and time-dependent is numerically analysed. If the hyaluronic acid concentration of the synovial gel at equilibrium is 50 mg/ml at least, the resulting stable gel layer thickness for the homogeneous filtration in the human hip joint and for normal synovial fluids is about 0.1 micron, being almost independent of the loading. Inflammatory synovial fluid shows values several times lower.

• MeSH
• adhezivita MeSH
• biologické modely * MeSH
• filtrace MeSH
• kloubní chrupavka anatomie a histologie   metabolismus   fyziologie   MeSH
• klouby anatomie a histologie   metabolismus   fyziologie   MeSH
• kyčelní kloub anatomie a histologie   metabolismus   fyziologie   MeSH
• kyselina hyaluronová metabolismus   fyziologie   MeSH
• lidé MeSH
• lubrikace MeSH
• makromolekulární látky MeSH
• mechanický stres MeSH
• permeabilita MeSH
• poréznost MeSH
• proteiny metabolismus   fyziologie   MeSH
• pružnost MeSH
• synoviální tekutina metabolismus   fyziologie   MeSH
• tělesná hmotnost MeSH
• tlak MeSH
• viskozita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina hyaluronová MeSH
• makromolekulární látky MeSH
• proteiny MeSH

In this study, fibrous membranes from recycled-poly(ethylene terephthalate)/silk fibroin (r-PSF) were prepared by electrospinning for filtration applications. The effect of silk fibroin on morphology, fibers diameters, pores size, wettability, chemical structure, thermo-mechanical properties, filtration efficiency, filtration performance, and comfort properties such as air and water vapor permeability was investigated. The filtration efficiency (FE) and quality factor (Qf), which represents filtration performance, were calculated from penetration through the membranes using aerosol particles ranging from 120 nm to 2.46 μm. The fiber diameter influenced both FE and Qf. However, the basis weight of the membranes has an effect, especially on the FE. The prepared membranes were classified according to EN149, and the most effective was assigned to the class FFP1 and according to EN1822 to the class H13. The impact of silk fibroin on the air permeability was assessed. Furthermore, the antibacterial activity against bacteria S. aureus and E. coli and biocompatibility were evaluated. It is discussed that antibacterial activity depends not only on the type of used materials but also on fibrous membranes' surface wettability. In vitro biocompatibility of the selected samples was studied, and it was proven to be of the non-cytotoxic effect of the keratinocytes (HaCaT) after 48 h of incubation.

• Klíčová slova
• air filtration, antibacterial activity, comfort properties, electrospun membrane, poly(ethylene terephthalate), silk fibroin,
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• BACILLUS MEGATERIUM *, CHROMATOGRAPHY *, DNA, BACTERIAL *, EXPERIMENTAL LAB STUDY *, RIBOSOMES *, RNA, BACTERIAL *, ULTRACENTRIFUGATION *,
• MeSH
• Bacillus megaterium * MeSH
• bakteriální RNA * MeSH
• buněčné extrakty * MeSH
• chromatografie * MeSH
• DNA bakterií * MeSH
• DNA * MeSH
• gelová chromatografie * MeSH
• ribozomy * MeSH
• RNA * MeSH
• ultracentrifugace * MeSH
• výzkum * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální RNA * MeSH
• buněčné extrakty * MeSH
• DNA bakterií * MeSH
• DNA * MeSH
• RNA * MeSH

Bacterial filtration efficiency is the main characteristic of medical face masks effectivity and quality. The testing method is given by European and US, respectively, standard. The method is based on the analysis of biological aerosol with the bacterium Staphylococcus aureus in Andersen cascade impactor. The Andersen impactor contains six stages simulating the different parts of the respiratory tract, from the upper part with the larger droplets to the lungs with the small aerosol particles of the submicron size. The particles are separated depending on the size and sediment on agar medium in Petri dishes filled in the impactor. The use of the glass Petri dishes is recommended for the Andersen impactor, but the most of laboratories prefer the disposable plastic dishes, actually. The evaluation of the use of plastic dishes in Andersen impactor for the determination of the bacterial filtration efficiency of the medical face masks is the aim of this study.

• Klíčová slova
• Aerosol, Andersen cascade impactor, Bacterial filtration efficiency, Face mask, Glass petri dish, Particles, Plastic petri dish, Positive hole conversion table, This research did not receive any specific grant from funding agencies.,
• MeSH
• aerosoly MeSH
• dýchací soustava * MeSH
• filtrace MeSH
• masky * MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aerosoly MeSH

BACKGROUND: The composition of extra virgin olive oil (EVOO) defines its sensory, nutritional, and human health benefits, and distinguishes it as a key component of the Mediterranean diet. Nevertheless, EVOO constituents are susceptible to degradation during processing and storage, which reduces the olive oil's quality and limits its shelf life. The present study investigated the effect of molecular filtration before storage and the effect of cool storage at 4 °C on the stability of 'Kolovi' EVOO, a variety originating from the Greek island of Lesvos, over a 24 month period. RESULTS: Storing EVOO at 4 °C positively affected free acidity, peroxide value, K268, fruity qualities, and concentrations of hydroxytyrosol, tyrosol, ligstroside aglycone, lutein, and squalene, in comparison with the control sample stored at room temperature, particularly after 1 year. Molecular filtration significantly affected the ratio of unsaturated fatty acids to saturated fatty acids (UFAs/SFAs). Optimal preservation of parameters such as acidity value and lutein content was achieved by combining molecular filtration with refrigeration. CONCLUSIONS: The present study recommends storing EVOO in the refrigerator for up to 18 months. Based on the regulatory limits of the quality characteristics of acidity, peroxide value, K232 value and fruity sensory attributes, the shelf-life of the protected geographical indication (PGI) 'Kolovi' EVOO can reach 2 years under cool storage (4 °C) and with molecular filtration before storage. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

• Klíčová slova
• EVOO, bioactive content, cool storage, molecular filtration, organoleptic characteristics, shelf‐life,
• MeSH
• chlazení * MeSH
• filtrace MeSH
• konzervace potravin metody   přístrojové vybavení   MeSH
• lidé MeSH
• Olea chemie   MeSH
• olivový olej * chemie   MeSH
• ovoce chemie   MeSH
• skladování potravin * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Geografické názvy
• Řecko MeSH
• Názvy látek
• olivový olej * MeSH

We developed a simple and fast microplate assay for evaluation of the antimicrobial activity of electrospun nanofiber filtration membranes or similar porous materials for water treatment technologies. Resazurin (alamarBlue®) was used as an indicator of the amount of viable experimental microorganisms Gram-negative Escherichia coli, Gram-positive Enterococcus faecalis, and natural wastewater treatment plant effluent bacteria. A bacterial inoculum of concentration 1-3 × 105 CFU mL-1 was pipetted onto the surface of assessed both functionalized and respective control membranes and incubated in 12-well plates for 4 h at 37 °C. Kinetics of resazurin metabolization, i.e. its reduction to fluorescent resorufin, was evaluated fluorimetrically (λex520/λem590 nm). A number of viable bacteria on the membranes expressed as CFU mL-1 was calculated from the kinetic curves by using calibration curves that were constructed for both experimental bacterial species. Antimicrobial activities of the membranes were evaluated by either resazurin assay or modified ISO 20743 plate count assay. Results of both assays showed the significant antimicrobial activity of membranes functionalized with silver nanoparticles for both bacterial species and wastewater treatment plant effluent bacteria as well (log CFU reduction compared to control membrane > 4), while membranes containing specific quaternary ammonium salts were inefficient (log CFU reduction < 1). The suitability of resazurin microplate assay for testing nanofiber filtration membranes and analogous matrices has proven to be a faster and less demanding alternative to the traditionally used approach providing comparable results.

• Klíčová slova
• Antimicrobial activity, Electrospun nanofiber filtration membranes, Quaternary ammonium salts, Resazurin, Silver nanoparticles,
• Publikační typ
• časopisecké články MeSH

Wasted synthetic fabrics are a type of textile waste source; the reuse of them brings environmental protection and turns waste into a valuable material. In this work, the used nylon (polyamide) stockings were transmuted into a fine fibrous membrane via an electrospinning process. In addition, the safety antibacterial agent, monoacylglycerol (MAG), was incorporated into a recycled fibrous membrane. The results revealed that the neat, recycled polyamide (rPA) fibers with a hydrophobic surface could be converted into hydrophilic fibers by blending various amounts of MAG with rPA solution prior to electrospinning. The filtration efficiency and air/water vapor permeability of the two types of produced membranes, neat rPA, and rPA/MAG, were tested. Their filtration efficiency (E100) was more than 92% and 96%, respectively. The membranes were classified according to Standard EN1822, and therefore, the membranes rPA and rPA/MAG were assigned to the classes E10 and E11, respectively. The air permeability was not affected by the addition of MAG, and water vapor permeability was slightly enhanced. Based on the obtained data, prepared rPA/MAG fibrous membranes can be evaluated as antifouling against both tested bacterial strains and antimicrobial against S. aureus.

• Klíčová slova
• antibacterial membrane, electrospinning, filtration, polyamide, recycling of textile waste, stocking,
• Publikační typ
• časopisecké články MeSH

BACKGROUND AND AIMS: Adefovir, an acyclic nucleotide reverse transcriptase inhibitor used to treat hepatitis B viral infection, is primarily eliminated renally through cooperation of glomerular filtration with active tubular transport. Nonalcoholic steatohepatitis is a variable in drug disposition, yet the impact on renal transport processes has yet to be fully understood. The goal of this study was to determine the effect of nonalcoholic steatohepatitis on the pharmacokinetics of adefovir in rats given a control or methionine and choline deficient diet to induce nonalcoholic steatohepatitis. METHODS: Animals received a bolus dose of 7mg/kg (35μCi/kg) [(3)H] adefovir with consequent measurement of plasma and urine concentrations. Inulin clearance was used to determine glomerular filtration rate. RESULTS: Methionine and choline deficient diet-induced nonalcoholic steatohepatitis prolonged the elimination half-life of adefovir. This observation occurred in conjunction with reduced distribution volume and hepatic levels of adefovir. Notably, despite these changes, renal clearance and overall clearance were not changed, despite markedly reduced glomerular filtration rate in nonalcoholic steatohepatitis. Alteration of glomerular filtration rate was fully compensated for by a significant increase in tubular secretion of adefovir. Analysis of renal transporters confirmed transcriptional up-regulation of Mrp4, the major transporter for adefovir tubular secretion. CONCLUSIONS: This study demonstrates changes to glomerular filtration and tubular secretion that alter pharmacokinetics of adefovir in nonalcoholic steatohepatitis. Nonalcoholic steatohepatitis-induced changes in renal drug elimination processes could have major implications in variable drug response and the potential for toxicity.

• Klíčová slova
• Adefovir, GFR, NASH, Renal elimination,
• MeSH
• adenin analogy a deriváty   farmakokinetika   MeSH
• cholin aplikace a dávkování   MeSH
• dieta MeSH
• hodnoty glomerulární filtrace MeSH
• inhibitory reverzní transkriptasy farmakokinetika   MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   metabolismus   MeSH
• methionin aplikace a dávkování   MeSH
• nealkoholová steatóza jater metabolismus   MeSH
• organofosfonáty farmakokinetika   MeSH
• potkani Sprague-Dawley MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• adefovir MeSH Prohlížeč
• adenin MeSH
• cholin MeSH
• inhibitory reverzní transkriptasy MeSH
• methionin MeSH
• organofosfonáty MeSH