AIMS: This study evaluates the effectiveness of two standard sterilization methods on microorganisms in bentonite, which is proposed as a buffer around metal canisters containing long-lived radioactive waste. Bentonite, as a natural clay, contains microorganisms with enhanced resistance to harsh conditions and the ability to reactivate upon decompaction. Sterile controls are crucial in experiments estimating the impact of microorganisms on nuclear waste repositories. Yet, the effectiveness of common sterilization methods on bentonite microorganisms has not been fully evaluated. METHODS AND RESULTS: Two methods were compared: dry heat (nine cycles at 121°C for 4 h) and gamma irradiation (10-140 kGy at 147 Gy·min-1). Molecular-genetic, microscopic, and cultivation techniques were used to assess sterilization. Heat sterilization did not eliminate heat-resistant microorganisms, such as Bacillus, Paenibacillus, and Terribacillus, from bentonite powder even after nine heat cycles. However, bentonite suspended in deionized water was sterile after four heat cycles. In contrast, gamma irradiation effectively reduced microbial survivability above a dose of 10 kGy, with the highest doses (100-140 kGy) potentially degrading DNA. CONCLUSIONS: Gamma irradiation at 30 kGy effectively sterilized bentonite powder. The findings of our experiments emphasize the importance of using appropriate sterilization methods to maintain sterile controls in experiments that evaluate the microbial impacts in nuclear waste repositories. However, further assessment is needed to determine the effects of potential alterations induced by gamma radiation on bentonite properties.
- Klíčová slova
- abiotic stress, hazardous waste, microbial diversity, radiation, sterilization,
- MeSH
- Bacteria účinky záření izolace a purifikace MeSH
- bentonit * MeSH
- radioaktivní odpad * analýza MeSH
- sterilizace * metody MeSH
- vysoká teplota * MeSH
- záření gama * MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- bentonit * MeSH
- radioaktivní odpad * MeSH
Pyrolysis emerges as a strategy for handling waste textiles, wherein the conversion of high-carbon-content textile waste into carbonaceous materials facilitates the restoration of its economic value, concurrently mitigating the environmental impact posed by textile waste. The present study fabricated carbon felts for respiratory filter layers through single-step pyrolysis of acrylic filter felts. The advantage of employing conductive carbon felt as a respiratory filter layer is its capability to concurrently serve two functions: filtration and electrical heating for high-temperature disinfection. In order to achieve these two functions, both the respirator body and the embedded electrodes were designed to ensure the reliability of high-temperature disinfection. The breathability and water vapor permeability of the obtained carbon felt were examined to confirm its comfortability as a respiratory filter layer. The results of filtration efficiency and antimicrobial testing indicated that the carbon felt exhibited a filtration efficiency of over 90 % against inhalable particulate matter, while its antimicrobial properties effectively suppressed microbial growth. This method of reutilizing waste textiles maintained consistency in the usage of textiles before and after reuse, simplified the reusing process of waste acrylic fibers, and simultaneously reduced the manufacturing costs of respiratory filters. The designed respiratory filters have the potential for application in settings such as hospitals and virus research institutions.
- Klíčová slova
- Acrylic fibrous waste, Carbon felt, Disinfection, Resistive heating, Respirator filter,
- MeSH
- dezinfekce metody MeSH
- filtrace * přístrojové vybavení metody MeSH
- prostředky na ochranu dýchání MeSH
- textilie * MeSH
- uhlík * chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- uhlík * MeSH
We investigated the production of highly reactive oxygen species (ROS) in solutions undergoing treatment using CaviPlasma (CP) technology. This technology combines plasma discharge with hydrodynamic cavitation. This study focused on factors such as pH, conductivity, presence of salts and organic matter affecting ROS formation and their stability in solutions. Depending on the used matrix, CP produces 450-580 µg L-1 s-1 of hydrogen peroxide and 1.9 µg L-1 s-1 of hydroxyl radicals dissolved in liquid. Using cyanobacteria and cyanotoxins as example, we proved that CP technology is a highly efficient method for destroying microorganisms and persistent toxins. The biocidal effect of the CP treatment was confirmed on two species of cyanobacteria, Synechococcus elongatus and Merismopedia minutissima. The effectiveness of the technology in degrading microcystins was also demonstrated. The potential of this technology is based on its high energy efficiency, G(H2O2) ≈ 10 g kWh-1 and G(O3) ≈ 0.03 g kWh-1 (in deionised water), realistic applicability with throughput rates (> 1 m3 h-1), and comparatively easy scalability system.
- Klíčová slova
- Cyanobacteria, Electric discharge, Hydrodynamic cavitation, Microcystins, Plasma-treated liquid, Radicals, Water treatment,
- MeSH
- dezinfekce * MeSH
- mikrocystiny MeSH
- peroxid vodíku MeSH
- reaktivní formy kyslíku * MeSH
- sinice * MeSH
- Synechococcus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- mikrocystiny MeSH
- peroxid vodíku MeSH
- reaktivní formy kyslíku * MeSH
Ultraviolet-C (UV-C) radiation and ozone gas are potential mechanisms employed to inactivate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), each exhibiting distinct molecular-level modalities of action. To elucidate these disparities and deepen our understanding, we delve into the intricacies of SARS-CoV-2 inactivation via UV-C and ozone gas treatments, exploring their distinct molecular-level impacts utilizing a suite of advanced techniques, including biological atomic force microscopy (Bio-AFM) and single virus force spectroscopy (SVFS). Whereas UV-C exhibited no perceivable alterations in virus size or surface topography, ozone gas treatment elucidated pronounced changes in both parameters, intensifying with prolonged exposure. Furthermore, a nuanced difference was observed in virus-host cell binding post-treatment: ozone gas distinctly reduced SARS-CoV-2 binding to host cells, while UV-C maintained the status quo. The results derived from these methodical explorations underscore the pivotal role of advanced Bio-AFM techniques and SVFS in enhancing our understanding of virus inactivation mechanisms, offering invaluable insights for future research and applications in viral contamination mitigation.
- Klíčová slova
- binding activity, infectivity test, sterilization mechanisms, structural characteristics, topographical characteristics,
- MeSH
- Cercopithecus aethiops MeSH
- COVID-19 * MeSH
- inaktivace viru * účinky léků účinky záření MeSH
- lidé MeSH
- mikroskopie atomárních sil * MeSH
- ozon * chemie farmakologie MeSH
- plazmové plyny chemie farmakologie MeSH
- SARS-CoV-2 * účinky léků MeSH
- sterilizace metody MeSH
- ultrafialové záření * MeSH
- Vero buňky MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- ozon * MeSH
- plazmové plyny MeSH
BACKGROUND: To prevent infectious complications after transrectal ultrasound-guided prostate biopsy (TRUS-PB), some studies have investigated the efficacy of rectal disinfection using povidone-iodine (PI) and antibiotic prophylaxis (AP). OBJECTIVE: To summarize available data and compare the efficacy of rectal disinfection using PI with non-PI methods prior to TRUS-PB. EVIDENCE ACQUISITION: Three databases were queried through November 2023 for randomized controlled trials (RCTs) analyzing patients who underwent TRUS-PB. We compared the effectiveness of rectal disinfection between PI groups and non-PI groups with or without AP. The primary outcomes of interest were the rates of overall infectious complications, fever, and sepsis. Subgroups analyses were conducted to assess the differential outcomes in patients using fluoroquinolone groups compared to those using other antibiotics groups. EVIDENCE SYNTHESIS: We included ten RCTs in the meta-analyses. The overall rates of infectious complications were significantly lower when rectal disinfection with PI was performed (RR 0.56, 95% CI 0.42-0.74, p < 0.001). Compared to AP monotherapy, the combination of AP and PI was associated with significantly lower risk of infectious complications (RR 0.54, 95% CI 0.40-0.73, p < 0.001) and fever (RR 0.47, 95% CI 0.30-0.75, p = 0.001), but not with sepsis (RR 0.49, 95% CI 0.23-1.04, p = 0.06). The use of fluoroquinolone antibiotics was associated with a lower risk of infectious complications and fever compared to non-FQ antibiotics. CONCLUSION: Rectal disinfection with PI significantly reduces the rates of infectious complications and fever in patients undergoing TRUS-PB. However, this approach does not show a significant impact on reducing the rate of sepsis following the procedure.
- Klíčová slova
- Antibiotic prophylaxis, Povidone-iodine, Transrectal ultrasound-guided prostate biopsy,
- MeSH
- antibiotická profylaxe metody MeSH
- antiinfekční látky lokální * terapeutické užití aplikace a dávkování MeSH
- dezinfekce metody MeSH
- jodovaný povidon * terapeutické užití aplikace a dávkování MeSH
- lidé MeSH
- nádory prostaty patologie MeSH
- prostata * patologie MeSH
- rektum * MeSH
- ultrazvukem navigovaná biopsie * škodlivé účinky metody MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- systematický přehled MeSH
Ultraviolet irradiation is an effective method of virus and bacteria inactivation. The dose of UV-C light necessary for baculovirus inactivation by measurement of fluorescent GFP protein produced by baculovirus expression system after the irradiation of baculovirus culture in doses ranging from 3.5 to 42 J/m2 was determined. At a dose of 36.8 J/m2, only 0.5% of GFP-expressing cells were detected by flow cytometry and confocal microscopy. The stability of purified VP1-PCV2bCap protein produced by baculovirus expression system was analyzed after the irradiation at doses ranging from 3.5 to 19.3 J/m2. Up to the dose of 11 J/m2, no significant effect of UV-C light on the stability of VP1-PCV2bCap was detected. We observed a dose-dependent increase in VP1-PCV2bCap-specific immune response in BALB/c mice immunized by recombinant protein sterilized by irradiation in dose 11 J/m2 with no significant difference between vaccines sterilized by UV-C light and filtration. A substantial difference in the production of VP1-PCV2bCap specific IgG was observed in piglets immunized with VP1-PCV2bCap sterilized by UV-C in comparison with protein sterilized by filtration in combination with the inactivation of baculovirus by binary ethylenimine. UV-C irradiation represents an effective method for vaccine sterilization, where commonly used methods of sterilization are not possible.
- MeSH
- myši MeSH
- prasata MeSH
- rekombinantní proteiny genetika MeSH
- sterilizace MeSH
- syntetické vakcíny * MeSH
- ultrafialové záření MeSH
- viry * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- rekombinantní proteiny MeSH
- syntetické vakcíny * MeSH
Sterilized processed cheese is a specific dairy product with a prolonged shelf life intended for regular retail offer but also as food provisions for armies during peacetime, as well as during crisis and emergency situations, and for storage in state material reserves. Storage requirements are usually defined as ≤25°C for at least 24 mo. One of the ways to achieve such a shelf life is sterilization. Therefore, the aim of the work was to describe, for the first time in the available scientific literature, in situ changes in the viscoelastic properties of spreadable melt (34% wt/wt DM content, 45% wt/wt fat in DM content, and 14% wt/wt protein content) during an increase in temperature (target temperature 122°C), holding at sterilization temperature (20 min) and subsequent cooling (to ~30°C). While increasing to the target sterilization temperature, a significant decrease occurred in the storage and loss moduli values. Both moduli started to increase again during the target sterilization temperature period and during the whole cooling phase. The values of the storage and loss moduli were significantly higher at the end of the cooling of the sterilized product, and conversely, the phase angle value was lower compared with the melt before sterilization. As a result of sterilization, an increase occurred in the levels of markers of the Maillard reaction complex and lipid oxidation processes. The value of hardness, corrected stress, and elongational viscosity also increased compared with nonsterilized products. As a result of sterilization, the flavor worsened and sterilized processed cheeses showed darker (brownish) color. However, even after sterilization, the products were evaluated as acceptable for consumers and maintained their spreadability.
- Klíčová slova
- heating, in situ study, processed cheese, rheology, sterilization,
- MeSH
- Maillardova reakce MeSH
- manipulace s potravinami MeSH
- nízká teplota MeSH
- sterilizace MeSH
- sýr * analýza MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY In clinical practice UHMWPE is the most commonly used material for manufacturing articular components of joint replacements. The purpose of this study is to find out whether repeated ethylene oxide sterilization results in oxidative degradation of UHMWPE or not and also whether the oxidative degradation of various types of ethylene oxide-sterilized UHMWPE depends on storage time or not. MATERIAL AND METHODS The set included 12 samples of UHMWPE (three samples with different modifications (virgin PE, with E vitamin and cross-linked with thermal treatment) and different number of sterilizations (0×-3×)). The set also included 8 samples of commercial components of hip or knee replacements sterilized with ethylene oxide and stored for different storage periods. The oxidative degradation was assessed by infrared microspectroscopy, based on which the oxidation index (OI), transvinylene index (VI), crystallinity index (CI) and E vitamin index (EI) were calculated. Mechanical properties of UHMWPE were obtained through microhardness measurements. Statistical processing of the results was performed. RESULTS In all the samples, very low oxidative degradation values were reported (most OI values < 0.1). All radiation crosslinked UHMWPE samples showed an increased VI index and a slightly lower crystallinity index. All unmodified samples (irrespective of whether or not and how many times or how long ago the samples were sterilized with EtO) had almost zero value of VI. Changes in crystallinity were negligible (in the rage of 0.56-0.63), which required very accurate measurements of micromechanical properties. Yet, linear correlation was established between microhardness and crystallinity. DISCUSSION All the mentioned indices changed as anticipated: OIs were very low and slightly increased with time of storage, VIs of radiation crosslinked samples grew in proportion to the total gama radiation dose, CIs decreased in samples thermally treated by remelting, and EIs were very low due to negligible concentration of stabiliser (0.1%) in the samples of medical grade UHMWPE. CONCLUSIONS All samples showed zero or minimum oxidative degradation. This confirmed that neither ethylene oxide sterilization, nor multiple EtO sterilization or longer storage of polymer after ethylene oxide sterilization result in major oxidative degradation. Key words: UHMWPE, ethylene oxide, sterilization, oxidation, infrared spectroscopy, microhardness.
- MeSH
- artroplastiky kloubů * MeSH
- ethylenoxid * MeSH
- lidé MeSH
- polyethyleny MeSH
- sterilizace metody MeSH
- vitaminy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- ethylenoxid * MeSH
- polyethyleny MeSH
- ultra-high molecular weight polyethylene MeSH Prohlížeč
- vitaminy MeSH
The increasing occurrence of algal and cyanobacterial blooms and the related formation of algal organic matter (AOM) is a worldwide issue that endangers the quality of freshwater sources and affects water treatment processes. The associated problems involve the production of toxins or taste and odor compounds, increasing coagulant demand, inhibition of removal of other polluting compounds, and in many cases, AOM acts as a precursor of disinfection by-products. Previous research has shown that for sufficient AOM removal, the conventional drinking water treatment based on coagulation/flocculation must be often accompanied by additional polishing technologies such as adsorption onto activated carbon (AC). This state-of-the-art review is intended to serve as a summary of the most current research on the adsorption of AOM onto AC concerning drinking water treatment. It summarizes emerging trends in this field with an emphasis on the type of AOM compounds removed and on the adsorption mechanisms and influencing factors involved. Additionally, also the principles of competitive adsorption of AOM and other organic pollutants are elaborated. Further, this paper also synthesizes previous knowledge on combining AC adsorption with other treatment techniques for enhanced AOM removal in order to provide a practical resource for researchers, water treatment plant operators and engineers. Finally, research gaps regarding the AOM adsorption onto AC are identified, including, e.g., adsorption of AOM residuals recalcitrant to coagulation/flocculation, suitability of pre-oxidation of AOM prior to the AC adsorption, relationships between the solution properties and AOM adsorption behaviour, or AOM as a cause of competitive adsorption. Also, focus should be laid on continuous flow column experiments using water with multi-component composition, because these would greatly contribute to transferring the theoretical knowledge to practice.
- Klíčová slova
- Activated carbon, Adsorption, Algal organic matter, Drinking water treatment, Micropollutants,
- MeSH
- adsorpce MeSH
- chemické látky znečišťující vodu * analýza MeSH
- čištění vody * MeSH
- dezinfekce MeSH
- dřevěné a živočišné uhlí MeSH
- pitná voda * MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- chemické látky znečišťující vodu * MeSH
- dřevěné a živočišné uhlí MeSH
- pitná voda * MeSH
We report the first halogen speciation analysis study by high performance liquid chromatography coupled with inductively coupled plasma tandem mass spectrometry (HPLC-ICPMS/MS) in the fruiting bodies of various mushroom species. Non-targeted speciation analysis revealed the occurrence of dichloroacetic acid (DCAA) in the edible mushroom Russula nigricans. Multiple samples of this mushroom (n = 5) collected from different geographic non-industrial regions in two different countries confirmed the consistent presence of this species at a relatively narrow concentration range (23-37 mg kg-1), whereas no other chlorinated acetic acid (e.g. chloroacetic acid and trichloroacetic acid) was detected. Neither DCAA nor any other chlorinated acetic acid were detected in any of the other mushroom species investigated in the present study, including seven different mushroom species of the same genus Russula, even though all mushrooms were collected from the same non-industrial geographic regions. Together with the previously reported biological activities of DCAA, these findings collectively suggest biosynthesis of this compound as an explanation for its dominant presence in R. nigricans, and constitute the first example of the dominant natural occurrence of this compound over other chlorinated acetic acids in a living organism. This may warrant a change in our view of the occurrence of dichloroacetic acid in nature, where primarily considered as a pollutant arising from water disinfection.
- Klíčová slova
- Dichloroacetic acid, Fungi, ICPMS/MS, Organohalogen,
- MeSH
- Agaricales * MeSH
- Basidiomycota MeSH
- dezinfekce MeSH
- kyselina dichloroctová * MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- kyselina dichloroctová * MeSH
- voda MeSH
