CDD plays a pivotal role within the pyrimidine salvage pathway. In this study, a novel, rapid method for the identification of cell lines lacking functional cytidine deaminase was developed. This innovative method utilizes immunocytochemical detection of the product of 5-fluorocytidine deamination, 5-fluorouridine in cellular RNA, enabling the identification of these cells within two hours. The approach employs an anti-bromodeoxyuridine antibody that also specifically binds to 5-fluorouridine and its subsequent detection by a fluorescently labeled antibody. Our results also revealed a strong correlation between the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio and cytidine deaminase content. On the other hand, no correlation was observed between the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio and deoxycytidine monophosphate deaminase content. Similarly, no correlation was observed between this ratio and equilibrative nucleoside transporters 1 or 2. Finally, concentrative nucleoside transporters 1, 2, or 3 also do not correlate with the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio.
- Klíčová slova
- 5-fluorocytidine deamination, 5-fluorouridine, cytidine deaminase, equilibrative and concentrative nucleoside transporters,
- MeSH
- buněčné linie MeSH
- cytidin analogy a deriváty metabolismus MeSH
- cytidindeaminasa * metabolismus nedostatek genetika MeSH
- lidé MeSH
- uridin analogy a deriváty metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- 5-fluorouridine MeSH Prohlížeč
- cytidin MeSH
- cytidindeaminasa * MeSH
- uridin MeSH
This study evaluates the removal efficiency of 15 estrogenic endocrine-disrupting compounds in two operational constructed wetlands with different designs: a hybrid system (constructed wetland A) and a horizontal system (constructed wetland B). The assessment involved analyzing composite water samples obtained from passive samplers through liquid chromatography-mass spectrometry coupled with yeast assays. Additionally, grab samples of sludge and sediment were examined to determine the endocrine-disrupting compound's adsorption efficacy. The application of the full logistic model enabled the discernment and ranking of the chemicals contributing to mixture toxicity. The findings revealed constructed wetland A's superior efficacy in the removal of individual endocrine-disrupting compounds (with an average efficiency of 94%) compared to constructed wetland B (60%). Furthermore, constructed wetland A displayed a higher estimated estrogenic activity removal efficiency (83%) relative to constructed wetland B (52%). Estrogenic activity was adequately accounted for (58-120%) in half of the analyzed samples, highlighting estrone as the primary estrogenic agent. The investigation underscores constructed wetlands' effectiveness in purging endocrine-disrupting compounds, suggesting that their integration as secondary or tertiary treatment systems for such pollutants removal merits further exploration.
- Klíčová slova
- constructed wetlands, endocrine-disrupting compounds, estrogenic activity, hybrid-constructed wetlands, tertiary treatment,
- MeSH
- chemické látky znečišťující vodu * chemie izolace a purifikace MeSH
- čištění vody * metody MeSH
- endokrinní disruptory * izolace a purifikace chemie MeSH
- mokřady MeSH
- odpad tekutý - odstraňování * metody MeSH
- odpadní voda * chemie MeSH
- recyklace * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chemické látky znečišťující vodu * MeSH
- endokrinní disruptory * MeSH
- odpadní voda * MeSH
This review summarizes the current knowledge in the field of preparing new and/or innovative materials that can be advantageously used for the sorption of emerging pollutants from water. This paper highlights new innovative materials such as transition metal-modified biochar, zeolites, clays, carbon fibers, graphene, metal organic frameworks, and aerogels. These materials have great potential for the removal of heavy metals from water, particularly due to their large surface area, nanoscale size, and availability of various functionalities; moreover, they can easily be chemically modified and recycled. This paper not only highlights the advantages and ever-improving physicochemical properties of these new types of materials but also critically points out their shortcomings and suggests possible future directions.
- Klíčová slova
- biochar, graphene, metal organic framework, nanotubes, sorption, water-treatment sorbent,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The purity of a steel is an important factor influencing the quality of the final products. Therefore, it is important to optimize the existing and develop new steelmaking technologies that affect the resulting purity. Electro slag remelting is a technology of tertiary metallurgy, which can advantageously be used to fabricate high quality steels. The study presents selected theoretical aspects of oxide systems and their specific influences on effectiveness of the electro slag remelting technology. The aim of this work was to experimentally analyze the purity of a tool steel fabricated by electro slag remelting using two different oxide systems (fused slags). The core of the study is the determination of the overall presence of elements in the steels, a thorough investigation of the presence of (not only) oxide-based inclusions within the investigated tool steel, and a detailed analysis of their chemical composition, including the size of these non-metallic inclusions, using energy dispersive X-ray (EDX) on the scanning electron microscope (SEM). Last but not least, the determination of the modification of the occurring non-metallic inclusions and verification of the experimentally acquired results as well as the calculation of the liquid and solid temperature and the calculation of the viscosity of the slags using the FactSage calculation software was performed. The results showed that the used slag influenced especially the occurrence of Mg and Al-based oxide inclusions. The CaS-type inclusions were present within all of the examined samples. The slag type influenced not only the typical morphology and size of the inclusions (especially of the CaS type), but also the tendency of the steel to exhibit localized corrosion when exposed to the ambient environment. This research can contribute to a better understanding of the effect of oxidation systems on the resulting purity and properties of ESR steels, thereby advancing the production of tool steels with higher quality and performance requirements.
- Klíčová slova
- chemical composition, electro slag remelting, non-metallic inclusion, slag, thermodynamics,
- Publikační typ
- časopisecké články MeSH
Differently substituted pyrrole-azo-benzene molecular photoswitches were prepared in a straightforward synthetic way. Their fundamental properties were investigated by XRD analysis, differential scanning calorimetry, thermogravimetric analysis, cyclic voltammetry, UV-Vis absorption spectroscopy, Hyper-Rayleigh Scattering, and NMR spectroscopy; the experimental results were further corroborated by DFT calculations. Thermal robustness, the HOMO/LUMO levels, and the absorption properties were altered mostly by substituting the N-methylpyrrole moiety and further fine-tuned by modifying the benzene substituents. The pyrrole substituent also proved crucial for the second-order non-linear optical (NLO) response as well as the photoswitching performance. Both fast and slow molecular switches can be designed with the half-life of the (Z) -isomer ranging from 48 seconds to 23.28 hours and the E/Z molar ratio up to 12/88. This comprehensive study allowed elucidation of the fundamental structure-property relationships and subsequently addresses the key aspects of the property tuning via substitution in molecular azo-photoswitches.
- Klíčová slova
- Azo-compounds, Hyper–rayleigh scattering, Non–linear optics, Photoswitch, Pyrrole,
- Publikační typ
- časopisecké články MeSH
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
During 2020-2021, the COVID-19 pandemic exposed significant vulnerabilities in hospital safety, with oxygen-related fires and explosions occurring at twice the usual rate. This highlighted insufficient preparedness for increased oxygen therapy demands and the associated risks of oxygen-enriched atmospheres. This study aimed to develop and test a smart monitoring system to detect increased oxygen concentrations in hospital environments, mitigating the risk of fires. Based on Internet of Things (IoT) technology, the system includes wireless sensors that measure oxygen levels at regular intervals and transmit the data to a database. Alerts are sent to hospital staff via short message service and e-mail when oxygen levels exceed predefined thresholds. The sensors were deployed in an intensive care unit and were validated through real-time measurements under hospital conditions. The system demonstrated high accuracy (±1%) in monitoring oxygen concentrations with low power consumption (345 µA for oxygen concentration measurements taken every minute). Notifications reliably informed staff of oxygen level thresholds, enabling timely interventions. The proposed IoT-based smart monitoring system is a cost-effective and efficient solution for improving safety in medical environments.
- Klíčová slova
- Internet of Things (IoT) technology, Low power sensor., Oxygen-related fire prevention, Smart medical gas detection, Wireless oxygen monitoring,
- MeSH
- bezdrátová technologie MeSH
- COVID-19 * MeSH
- internet věcí MeSH
- jednotky intenzivní péče MeSH
- kyslík * analýza MeSH
- lidé MeSH
- monitorování fyziologických funkcí metody MeSH
- nemocnice MeSH
- oxygenoterapie metody MeSH
- pandemie MeSH
- pilotní projekty MeSH
- SARS-CoV-2 izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kyslík * MeSH
In recent decades, global change and local anthropogenic pressures have severely affected natural ecosystems and their biodiversity. Although disentangling the effects of these factors is difficult, they are reflected in changes in the functional composition of plant communities. We present a comprehensive, large-scale analysis of long-term changes in plant communities of various non-forest habitat types in the Czech Republic based on 1154 vegetation-plot time series from 53 resurvey studies comprising 3909 vegetation-plot records. We focused not only on taxonomic diversity but also on the functional characteristics of communities. Species richness of most habitat types increased over time, and taxonomic and functional community composition shifted significantly. Habitat specialists and threatened species became less represented in plant communities, indicating a decline in habitat quality. The spread of trees, shrubs, tall herbaceous plants, strong competitors, and nutrient-demanding species in all non-forest habitats, coupled with the decline of light-demanding species, suggests an effect of eutrophication and natural succession following the abandonment of traditional management. Moreover, we identified specific trends in certain habitats. In wetlands, springs, and mires, moisture-demanding species decreased, probably due to drainage, river regulations, and increasing drought resulting from climate change. Dry grasslands, ruderal, weed, sand, and shallow-soil vegetation became more mesic, and successional processes were most pronounced in these communities, suggesting a stronger effect of abandonment of traditional management and eutrophication. In alpine and subalpine vegetation, meadows and mesic pastures, and heathlands, insect-pollinated species declined, and the proportion of grasses increased. Overall, these functional changes provide deep insights into the underlying drivers and help conservationists take appropriate countermeasures.
- Klíčová slova
- biodiversity change, drought, eutrophication, functional traits, habitat specialists, mesophilization, succession, vascular plants,
- MeSH
- biodiverzita * MeSH
- ekosystém * MeSH
- klimatické změny MeSH
- rostliny * klasifikace MeSH
- zachování přírodních zdrojů MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Cathelicidins are a group of cationic, amphipathic peptides that play a vital role in the innate immune response of many vertebrates, including humans. Produced by immune and epithelial cells, they serve as natural defenses against a wide range of pathogens, including bacteria, viruses, and fungi. In humans, the cathelicidin LL-37 is essential for wound healing, maintaining skin barrier integrity, and combating infections. Cathelicidins of different origins have shown potential in treating various skin conditions, including melanoma, acne, and diabetic foot ulcers. Despite their promising therapeutic potential, cathelicidins face significant challenges in clinical application. Many peptide-based therapies have failed in clinical trials due to unclear efficacy and safety concerns. Additionally, the emergence of bacterial resistance, which contradicts initial claims of non-resistance, further complicates their development. To successfully translate cathelicidins into effective clinical treatments, therefore, several obstacles must be addressed, including a better understanding of their mechanisms of action, sustainable large-scale production, optimized formulations for drug delivery and stability, and strategies to overcome microbial resistance. This review examines the current knowledge of cathelicidins and their therapeutic applications and discusses the challenges that hinder their clinical use and must be overcome to fully exploit their potential in medicine.
- Klíčová slova
- cathelicidins, clinical trials, peptide formulations, recombinant production, resistance mechanism, skin drug delivery, wound healing,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND: The primary objective of this study was to conduct a comprehensive questionnaire survey on the practices of research ethics committees reviewing academic research projects in Czechia. The study aims to provide an unbiased and objective assessment of the current practices of research ethics committees, namely to obtain the missing data on their functioning in the context of academic research, to identify difficulties and shortages that threaten the responsible functioning of research ethics committees in the country and to investigate the implementation of Additional Protocol on Biomedical Research CETS No. 195 in their practice. Such research has never been conducted in Czechia. METHODS: This was a mixed-methods study, in which the online survey with closed and open-ended questions was chosen to explore the situation regarding ethics assessment of research involving human participants. We developed a questionnaire containing 18 questions concerning several aspects of the functioning of research ethics committees. The questionnaire was in Czech language and was administered through the Qualtrics platform anonymously. The target group of 61 research ethics committees at research institutions was approached by emails and we received 43 completely filled questionnaires, i.e., response rate of 67%. RESULTS: We obtained valuable data on the functioning of research ethics committees in Czechia in three main domains: the mandate and composition of the committee; the scope of its agenda; the process of evaluation including the voting procedure. In addition, the final set of open-ended questions provided an in-depth look at the problems faced by research ethics committees in Czechia. From the results is evident that the responsible assessment of the ethics of research involving human subjects is still not satisfactorily addressed and established for routine practice in the country. CONCLUSIONS: The outcomes of our study revealed that the main problem of research ethics in Czechia is the lack of national legislation on research ethics governance. To address this problem, the country requires a legislative framework accompanied by supportive measures aimed at educating, guiding and advising research ethics committees, especially in the Czech academic environment. TRIAL REGISTRATION NUMBER: Not applicable.
- Klíčová slova
- academic research institutions, human subject research, international ethics standards, research ethics, research ethics committees, research ethics governance,
- MeSH
- biomedicínský výzkum etika MeSH
- etické komise - výzkum * MeSH
- etické zhodnocení MeSH
- etika výzkumu * MeSH
- experimenty na lidech etika MeSH
- lidé MeSH
- průzkumy a dotazníky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
