Compacted bentonites are one of the best sealing and backfilling clays considered for use in Deep Geological Repositories of radioactive wastes. However, an in-depth understanding of their behavior after placement in the repository is required, including if the activity of indigenous microorganisms affects safety conditions. Here we provide an optimized phenol:chloroform based protocol that facilitates higher DNA-yields when other methods failed. To demonstrate the efficiency of this method, DNA was extracted from acetate-treated bentonites compacted at 1.5 and 1.7 g/cm3 densities after 24 months anoxic incubation. Among the 16S rRNA gene sequences identified, those most similar to taxa mediating biogeochemical sulfur cycling included sulfur oxidizing (e.g., Thiobacillus, and Sulfurimonas) and sulfate reducing (e.g., Desulfuromonas and Desulfosporosinus) bacteria. In addition, iron-cycling populations included iron oxidizing (e.g., Thiobacillus and Rhodobacter) plus reducing taxa (e.g., Geobacillus). Genera described for their capacity to utilize acetate as a carbon source were also detected such as Delftia and Stenotrophomonas. Lastly, microscopic analyses revealed pores and cracks that could host nanobacteria or spores. This study highlights the potential role of microbial driven biogeochemical processes in compacted bentonites and the effect of high compaction on microbial diversity in Deep Geological Repositories.
The potential of new trimetallic (Ce, Cu, La) loaded montmorillonite clay catalyst for synthesizing biodiesel using novel non-edible Celastrus paniculatus Willd seed oil via two-step transesterification reaction has been reported along with catalyst characterization. Transesterification reaction was optimized and maximum biodiesel yield of 89.42% achieved under optimal operating reaction states like; 1:12 oil to methanol ratio, 3.5% of catalyst amount, 120 °C of reaction temperature for 3 h. The predicted and experimental biodiesel yields under these reaction conditions were 89.42 and 89.40%, which showing less than 0.05% variation. Additionally, optimum biodiesel yield can be predicted by drawing 3D surface plots and 2D contour plots using MINITAB 17 software. For the characterization of the obtained biodiesel, analysis including the GC/MS, FT-IR, 1H NMR and 13C NMR were applied. The fuel properties of obtained biodiesel agrees well with the different European Union (EU-14214), China (GB/T 20828), and American (ASTM-951, 6751) standards.
- MeSH
- bentonit * MeSH
- biopaliva * analýza MeSH
- esterifikace MeSH
- katalýza MeSH
- oleje rostlin analýza MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Čína MeSH
BACKGROUND: The red-crowned crane (Grus japonensis) is one of the most vulnerable bird species in the world. Mycotoxins are toxic secondary metabolites produced by fungi and considered naturally unavoidable contaminants in animal feed. Our recent survey indicated that the mycotoxins had the potential to contaminate redcrowned crane's regular diets in China. OBJECTIVE: This experiment was conducted to investigate the protective effects of mycotoxin binder montmorillonite (Mont) on growth performance, serum biochemistry and oxidative stress parameters of the red-crowned crane. METHODS: 16 red-crowned cranes were divided into four groups and fed one of the following diets; a selected diet, regular diet, or the selected diet or regular diet with 0.5% montmorillonite added to the diets. The cranes' parameters of performance, hematology, serum biochemistry and serum oxidative stress were measured. RESULTS: Consuming regular diets decreased the average daily feed intake (ADFI), levels of haemoglobin (Hb), platelet count (PLT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), but increased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH). The supplementation of 0.5% Mont provided protection for the red-crowned crane in terms of feed intake, serum biochemistry and oxidative stress. Moreover, Mont supplementation had no adverse effect on the health of red-crowned crane. CONCLUSIONS: Taken together, these findings suggested that the addition of dietary Mont is effective in improving the health of red-crowned crane.
The red-crowned crane (Grus japonensis) is a vulnerable bird species. Mycotoxins are toxic substances produced by filamentous fungi and are considered as naturally unavoidable contaminants in animal feed. Our recent survey indicated that feeds designed for captive red-crowned cranes were contaminated with mycotoxins. This study was conducted to investigate the protective effects of the mycotoxin binder montmorillonite on the reproductive behavior, sex hormone levels, and egg quality of red-crowned cranes. Twelve pairs of G. japonensis were divided into four groups, and each group was fed one of the following: a selected diet (with extra low levels of mycotoxins), a regular diet, a selected diet with 0.5% montmorillonite added, or a regular diet with 0.5% montmorillonite added. Consumption of the regular diet decreased courtship and mating behaviors, testosterone concentration, egg weight, and shell thickness. However, feed supplementation with montmorillonite increased the courtship, mating behaviors and testosterone concentration during the pre-breeding period, as well as egg weight and shell thickness. These findings suggest that the addition of dietary montmorillonite is effective for controlling mycotoxins in the feed, resulting in improvements in reproductive behaviors, testosterone concentrations, and some egg quality parameters of the red-crowned crane.
- MeSH
- bentonit chemie MeSH
- dieta MeSH
- krmivo pro zvířata analýza normy MeSH
- mykotoxiny analýza toxicita MeSH
- ovum chemie MeSH
- pohlavní steroidní hormony krev MeSH
- ptáci fyziologie MeSH
- rozmnožování účinky léků MeSH
- sexuální chování zvířat účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The release of phosphorus (P) from bed sediments to the overlying water can delay the recovery of lakes for decades following reductions in catchment contributions, preventing water quality targets being met within timeframes set out by environmental legislation (e.g. EU Water Framework Directive: WFD). Therefore supplementary solutions for restoring lakes have been explored, including the capping of sediment P sources using a lanthanum (La)-modified bentonite clay to reduce internal P loading and enhance the recovery process. Here we present results from Loch Flemington where the first long-term field trial documenting responses of phytoplankton community structure and abundance, and the UK WFD phytoplankton metric to a La-bentonite application was performed. A Before-After-Control-Impact (BACI) analysis was used to distinguish natural variability from treatment effect and confirmed significant reductions in the magnitude of summer cyanobacterial blooms in Loch Flemington, relative to the control site, following La-bentonite application. However this initial cyanobacterial response was not sustained beyond two years after application, which implied that the reduction in internal P loading was short-lived; several possible explanations for this are discussed. One reason is that this ecological quality indicator is sensitive to inter-annual variability in weather patterns, particularly summer rainfall and water temperature. Over the monitoring period, the phytoplankton community structure of Loch Flemington became less dominated by cyanobacteria and more functionally diverse. This resulted in continual improvements in the phytoplankton compositional and abundance metrics, which were not observed at the control site, and may suggest an ecological response to the sustained reduction in filterable reactive phosphorus (FRP) concentration following La-bentonite application. Overall, phytoplankton classification indicated that the lake moved from poor to moderate ecological status but did not reach the proxy water quality target (i.e. WFD Good Ecological Status) within four years of the application. As for many other shallow lakes, the effective control of internal P loading in Loch Flemington will require further implementation of both in-lake and catchment-based measures. Our work emphasizes the need for appropriate experimental design and long-term monitoring programmes, to ascertain the efficacy of intervention measures in delivering environmental improvements at the field scale.
- MeSH
- bentonit * terapeutické užití MeSH
- dekontaminace * metody MeSH
- lidé MeSH
- nebezpečné látky toxicita MeSH
- Check Tag
- lidé MeSH
Článek volně navazuje na příspěvek o derivátech celulosy (1) a pojednává o dalších látkách používaných pro zvyšování viskozity roztoků, stabilizaci suspenzí, emulzí a tvorbu gelů. Některé z nich jsou tradičními pomocnými látkami při magistraliter přípravě (např. agar, tragant, želatina). Jiné se používají běžně v potravinářství, kosmetických přípravcích, ve farmacii v tabletách a systémech s řízených uvolňováním léčiv, ale v individuální přípravě léků jsou používány zřídka (např. xanthanová klovatina, směs mikrokrystalické celulosy a karmelosy sodné soli). V lékárenské praxi se lze setkat s gely k aplikaci na sliznici dutiny ústní obsahující antibiotika nebo lokální anestetika. Bylo zjištěno, že doba rozpadu těchto gelů je významně ovlivněna typem a koncentrací polymeru a použitého chuťového korigencia. Některé formulace nejsou vhodné z hlediska compliance pacienta ani z hlediska terapeutického.
The paper continues the contribution of cellulose derivatives (1) and deals with other substances used for viscosity of solutions increasing, stabilization of suspensions and emulsions, and gels forming. Some of these are traditional excipients in the extemporaneous preparation (for example agar, tragacanth, and gelatin), other are used conventionally in food industry, cosmetics, in pharmacy as excipients in tablets and controlled release but rarely in the extemporaneous preparation (for example xanthan gum, mixture of microcrystalline cellulose and carmellose sodium). Gels for application to the oral mucosa containing antibiotics or local anaesthetics are prescribed in the pharmaceutical practice. It was found that the dissolution time of these gels is significantly influenced by the type and concentration of polymer and flavouring agents used. Some formulations are not appropriate in terms of patient compliance and also therapeutic effect. Starch, pregelatinised, Xanthan gum, Tragacanth.
- Klíčová slova
- gely k aplikaci na sliznici dutiny ústní, rychlost rozpouštění gelů, arabská klovatina, karmelosa sodná sůl, xanthanová klovatina,
- MeSH
- agar chemie MeSH
- bentonit chemie MeSH
- celulosa chemie MeSH
- chuťové esence * MeSH
- farmaceutická technologie * MeSH
- farmaceutické pomocné látky * MeSH
- gely * aplikace a dávkování farmakokinetika farmakologie chemie terapeutické užití MeSH
- karagenan MeSH
- konzervační prostředky farmaceutické MeSH
- kyselina alginová MeSH
- lidé MeSH
- oxid křemičitý chemie MeSH
- polymery * farmakologie chemie klasifikace terapeutické užití zásobování a distribuce MeSH
- příprava léků * MeSH
- škrob chemie MeSH
- tragant chemie MeSH
- želatina chemie MeSH
- Check Tag
- lidé MeSH
The degradation mechanism and kinetics of polylactic acid (PLA) nanocomposite films, containing various commercially available native or organo-modified montmorillonites (MMT) prepared by melt blending, were studied under composting conditions in thermophilic phase of process and during abiotic hydrolysis and compared to the pure polymer. Described first order kinetic models were applied on the data from individual experiments by using non-linear regression procedures to calculate parameters characterizing aerobic composting and abiotic hydrolysis, such as carbon mineralization, hydrolysis rate constants and the length of lag phase. The study showed that the addition of nanoclay enhanced the biodegradation of PLA nanocomposites under composting conditions, when compared with pure PLA, particularly by shortening the lag phase at the beginning of the process. Whereas the lag phase of pure PLA was observed within 27days, the onset of CO2 evolution for PLA with native MMT was detected after just 20days, and from 13 to 16days for PLA with organo-modified MMT. Similarly, the hydrolysis rate constants determined tended to be higher for PLA with organo-modified MMT, particularly for the sample PLA-10A with fastest degradation, in comparison with pure PLA. The acceleration of chain scission in PLA with nanoclays was confirmed by determining the resultant rate constants for the hydrolytical chain scission. The critical molecular weight for the hydrolysis of PLA was observed to be higher than the critical molecular weight for onset of PLA mineralization, suggesting that PLA chains must be further shortened so as to be assimilated by microorganisms. In conclusion, MMT fillers do not represent an obstacle to acceptance of the investigated materials in composting facilities.
Sorption efficiencies of modified montmorillonite and vermiculite of their mono ionic Na and organic HDTMA and HDP forms were studied against chemical and biological warfare agents such as yperite and selected bacterial strains. Yperite interactions with modified clay minerals were observed through its capture in low-density polyethylene foil-modified clay composites by measuring yperite gas permeation with using chemical indication and gas chromatography methods. The antibacterial activities of synthetized organoclays were tested against selected Gram-positive and Gram-negative bacterial species in minimum inhibitory concentration tests. The obtained results showed a positive influence of modified clay minerals on the significant yperite breakthrough-time increase. The most effective material was the polyethylene-Na form montmorillonite, while the polyethylene-Na form vermiculite showed the lowest efficiency. With increasing organic cations loading in the interlayer space the montmorillonite efficiency decreased, and in the case of vermiculite an opposite effect was observed. Generally the modified montmorillonites were more effective than modified vermiculites. The HDP cations seem to be more effective compare to the HDTMA. The antibacterial activity tests confirmed efficiency of all organically modified clay minerals against Gram-positive bacteria. The confirmation of antibacterial activity against Y. pestis, plague bacteria, is the most interesting result of this part of the study.
- MeSH
- akrylové pryskyřice chemie MeSH
- bentonit chemie farmakologie MeSH
- biologické bojové látky * MeSH
- chemické bojové látky chemie MeSH
- gramnegativní bakterie účinky léků růst a vývoj MeSH
- grampozitivní bakterie účinky léků růst a vývoj MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- ochranné oděvy * MeSH
- polyethylen chemie MeSH
- silikáty hliníku chemie farmakologie MeSH
- yperit chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cieľ. Magnetická rezonancia je výberovou modalitou v zobrazovaní tenkého čreva vzhľadom na vysoké rozlíšenie mäkkého tkaniva, multiplanárnu akvizíciu, možnosť vykonávať funkčné štúdie, absenciu radiačného žiarenia, obzvlášť u detí a mladšej populácie. Z technického hľadiska je nutná príprava tenkého čreva - jeho dostatočná distenzia, zamedzenie pohybových artefaktov a prijateľná doba vyšetrenia. Distenzia sa dá dosiahnuť dvoma spôsobmi, buď perorálnou náplňou, alebo cez zavedenú nazojejunálnu sondu. Kontrastné perorálne látky sú charakterizované ako pozitívne, negatívne alebo bifázické. Metoda. Štúdia je rozdelená do troch skupín. V 1. skupine je17 zdravých dobrovoľníkov. Po 6-8hodinovom lačnení pili frakcionovane 1000 ml perorálneho roztoku v priebehu 50 minút. Potom sa vykonala MREg (magnetická rezonančná enterografia) bez podania kontrastnej látky a spazmolytika. V 2. skupine bolo realizované MRCP u 24 chorých s rôznymi diagnózami a v rámci prípravy pred vyšetrením sme podávali v množstve 500 ml perorálny nálev 30 minút pred vyšetrením frakcionovane. V poslednej skupine sú zatiaľ chorí s Crohnovou chorobou, zápalovým ochorením čreva atď. - štúdia nie je ešte ukončená. Všetky vyšetrenia boli realizované na 1,5T systéme (Signa Horizon Lx, GE, Milwaukee, Wisconsin, USA), protokol vyšetrenia pri MREg: axiálna/koronálna rovina zadržaním dychu, všetci chorí a dobrovoľníci vyplnili dotazník o charakteristike roztoku. Štyria rádiologovia nezávisle hodnotili vyšetrenia v 1. a 2. skupine. Tretia štúdia nie je ukončená, a preto nebola štatisticky analyzovaná. Analýza bola spracovaná štatistickými metódami ?2-testom dobrej zhody a kontingenčnými tabuľkami na hladine významnosti 5 %. Výsledky. Z hodnotení dotazníkov 1. a 2. skupiny o charakteristike experimentálneho roztoku vyplýva existencia závislosti chuti a vzhľadu roztoku, ovocná chuť je spojená s obstojným vzhľadom a dobrou chuťou roztoku, kovová a syntetická chuť je spojená s nepekným vzhľadom a nie dobrou chuťou roztoku. Štatistickou analýzou bola dokázaná závislosť medzi problémami počas pitia (diarrhoe, nauzea, flatulencia, gargoizmus) a rovnakými pretrvávavajúcimi problémami po 2 hodinách po vypití roztoku. Bola vypozorovaná závislosť medzi kovovou, respektíve syntetickou, chuťou roztoku a pridruženou nauzeou. V oboch skupinách boli vypozorované rovnaké vedľajšie prejavy počas pitia (diarrhoe, nauzea, flatulencia, gargoizmus) a 2 hodiny po vypití v závislosti od chuti a množstva nálevu. Zo štatistickej analýzy a hodnotenia vyšetrení štyrmi rádiológmi v 1. a 2. skupine vyplýva hodnotiteľnosť MREg, MRCP, T2 váž. obrazu, SNR v T2 váž. obraze a sú dokázateľne závislé od náplne lúmenu. V 95 % sa všetci štyri rádiológovia zhodli v odpovediach na otázky. Podľa hodnotenia dotazníkov v skupine zdravých jedincov radiológmi je dostatočná koncentrácia 800 mg maghemit maghemit (gamma-Fe2O3)/4g bentonit v 1000 ml roztoku. Záver. Perorálny nálev s použitím SPIO nanopartikúl maghemitu (800 mg) v bentonitovej matrici v 1000 ml roztoku je vhodný pre vyšetrenie tenkého čreva pomocou MREg. Bude potrebné ďalej skúmať hodnotenie zápalových ochorení tenkého čreva a MREg s použitím SPIO orálnej kontrastnej látky.
Aim. Magnetic resonance is a method of choice in small bowel imaging according to high resolution of soft tissue, multiplanar acquisition, possibility of functional studies, absence of radiation, especially in children and younger population. From technical point of view small bowel preparation is necessary - sufficient distension, avoiding of motion artifacts, acceptable examination time. Small bowel distension can be reached in 2 ways, peroral filling or fillling through nasojejunal tube. Oral contrast agents are characterized as positive, negative or biphasic. Method. Study is divided into 3 groups. There are 17 healthy volunteers in the first group. After 6-8 hours of fasting, they drank fractionally 1000 ml peroral solution within 50 minutes. Then followed MREg (magnetic resonance enterography) without intravenous contrast agent and spasmolytic agent. Second group was realized in 24 patients with MRCP (magnetic resonance pancreatico- cholangiography) with various diagnoses, as small bowel preparation we gave them 500 ml of peroral solution fractionally within 30 minutes. Last group consists of patients with Crohn?s disease, inflammatory bowel disease, etc, study is not finished yet. All examinations were realized on 1,5T system (Signa Horizon Lx, GE, Milwaukee, Wisconsin, USA), examination protocol in MREg: breathhold axial/coronal plane 2D T2 SSFSE (single-shot fast spine-scho) , all patients and 2D T2 SSFSE (single-shot fast spine-scho) so volunteers fulfilled questionnaire about the solution characterization, 4 radiologists independently evaluated the examinations in first two groups. Third group was not statistically analyzed because of it is not finished yet. Analysis was made by statistic methods of ?2-test of good agreement and contingent tables with level of significance 5%. Results. Evaluation of the questionnaires about solution characterization in first and second group resulted in existence of dependence on solution taste and appearance, fruity taste is connected with sufficient appearance and good solution taste, metalic and synthetic taste is connected with bad appearance and not good solution taste. According to statistic analysis, there is dependence between problems during drinking (diarrhoe, nausea, flatulence and gargoism) and problems remaining 2 hours after drinking solution. There was seen dependance between metalic, synthetic solution taste, associated nausea respectively. Adverse effects during drinking and after 2 hours drinking (diarrhoe, nausea, flatulence and gargoism) were present in both groups in dependance of solution taste and volume. Evaluation of MREg, MRCP, T2 weighted images is dependend on quality of luminal filling according to statistical analysis and 4 radiologists evaluation of first and second group. In 95% all 4 radiologists were agreed in answers for questions. Based on evalution of the questionnaires, 800 mg maghemit/4 g bentonit in 1000 ml of solution is sufficient concentration. Conclusion. Oral contrast agent with SPIO nanoparticles of maghemit (800 mg) in bentonit matrix in 1000 ml solution, is appropriate for small bowel examination with MREg. Further study will be necessary for evaluation of inflammatory bowel diseases and MREg with SPIO oral contrast agent.
- Klíčová slova
- maghemit,
- MeSH
- bentonit diagnostické užití MeSH
- kontrastní látky diagnostické užití MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- nanočástice diagnostické užití MeSH
- studie případů a kontrol MeSH
- tenké střevo MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- grafy a diagramy MeSH
- hodnotící studie MeSH
