In this study the compressive strength and durability of soft clay soil stabilized with halloysite nanotubes are investigated. Halloysite nanotubes are novel 1D natural nanomaterials which are widely used in reinforcing polymer, pollution remediation, and as nanoreactors for biocatalyst. The wide use of halloysite nanotubes is due to their high aspect ratio, appropriate mechanical strength, high thermal stability, nature-friendly and cost-effectiveness. However, the use of halloysite nanotubes as a stabilizing agent for improving the durability of soil is not clear. In this research, halloysite nanotubes was used in the amounts of 2%, 5% and 10% by the weight of dried soil. Unconfined compressive strength, wet/dry cycles and freeze/thaw cycles tests were performed to evaluate the strength and durability of stabilized soft clay soil. Experimental results showed that halloysite nanotubes considerably improves the compressive strength and durability of soft clay soil. The optimum amount of halloysite nanotubes for soil stabilizing in terms of compressive strength and durability was 5%. The compressive strength of soft clay increased as much as 129% by applying 5% halloysite nanotubes. Also, the specimen containing 5% halloysite nanotubes showed the least strength loss after wet/dry and freeze/thaw cycles. The soil sample containing 5% halloysite nanotubes lost 20% of its initial compressive strength after 8 cycles of freezing and thawing, while the soil sample without any halloysite content lost 100% of its compressive strength after the same number of freezing and thawing. Based on the obtained results, the use of halloysite nanotubes in order to enhance the strength and durability of soft clay is strongly recommended., Tavakolipour Masoud, Salemi Niloofar., and Obsahuje bibliografické odkazy
Gestageny mají různé biologické vlastnosti, na které bereme ohled při jejich volbě. V hormonální substituční terapii volíme progestin dle jeho metabolické neutrálnosti a bezpečnosti vzhledem k možnému riziku onemocnění karcinomem prsu. Mikronizovaný progesteron a dydrogesteron mají pravděpodobně lepší bezpečnostní profil než syntetické progestiny. Také v suplementaci gestagenů v těhotenství dáváme přednost přirozeným gestagenům před syntetickými progestiny. Klíčová slova: dydrogesteron – časné těhotenské ztráty – poruchy menstruačního cyklu – hormonální substituční terapie – předčasný porod, Progestagens have oferent biologic affects which must be included into therapeutic choice. The best progestogen for the hormone replacement therapy could be metabolic neutral and safe for breast tissue. Micronised progesterone and dydrogesterone have better safety profile than synthetic progestagens. Also during pregnancy we prefer natural gestagens to synthetic ones. Key words: dydrogesterone – early pregnancy loss – hormone replacement therapy – menstrual cycle disturbance – preterm labor, and Tomáš Fait
In this study, we describe changes of plasma levels of the hypothalamic neuropeptide orexin A in obese children during the reduction of body weight and its relationship to other biochemical and anthropometrical parameters. We measured orexin A fasting plasma levels by the RIA method in 58 obese children - 33 girls and 25 boys; mean age 13.1±0.38 years (range 7-18.5) before and after 5 weeks of weight-reduction therapy. Leptin, IGF-1, and IGFBP-3 levels were measured in all the subjects and were compared to orexin A levels and anthropometrical data. Average weight in subjects before weight-reduction was 74.2±2.79 kg and after weight-loss 67.4±2.60 kg (p<0.0001). Orexin A levels before the therapy were 33.3±1.97 pg/ml and after the therapy 51.7±3.07 pg/ml (p<0.0001). Levels of orexin A were not significantly different between girls and boys (p=0.7842). We found negative correlation between orexin A and age (r = -0.5395; p<0.0001), body height (r = -0.4751; p=0.0002), body weight (r = -0.4030; p=0.0017) and BMI (r = -0.2607; p=0.0481). No correlation was found between orexin A and IGF-1, IGFBP-3 or leptin. Orexin A plasma levels increased during body weight loss, whereas the reverse was true for leptin levels. These findings support the hypothesis that orexin A may be involved in regulation of nutritional status in children., J. Bronský, J. Nedvídková, H. Zamrazilová, M. Pechová, M. Chada, K. Kotaška, J. Nevoral, R. Průša., and Obsahuje bibliografii a bibliografické odkazy
Úvod: Dynamické metody kvantitativního testování senzitivity (Quantitative Sensory Testing; QST) jsou relativně novou nadstavbovou aplikací QST umožňující objektivizovat funkci centrálních modulačních mechanizmů algické percepce, jejichž individuální nastavení může přispívat k rozvoji chronických bolestivých stavů. Testování těchto mechanizmů umožňuje např. predikci rozvoje pooperační bolesti. K nejčastěji hodnoceným dynamickým QST metodám patří tzv. podmíněná modulace bolesti (Conditioned Pain Modulation; CPM) a časová sumace percepce bolestivých podnětů (Temporal Summation; TS). Soubor a metodika: Vyšetření dQST (dynamic methods of Quantitative Sensory Testing) metod s využitím termoalgických podnětů a modulace bolestivým chladem bylo provedeno u 77 zdravých dobrovolníků (47 žen testovaných v ovulační fázi menstruačního cyklu, 30 mužů, věk 19–73 let). Hodnocen byl také vliv věku a pohlaví na výsledky obou dQST testů. Výsledky: Uspokojivá funkce podmíněné modulace bolesti byla prokázána u 84 % testovaných dobrovolníků. Časová sumace bolestivých podnětů byla zachycena u 92, resp. 98 % jedinců v závislosti na použité teplotě podnětů. Nefunkčnost mechanizmů u zbylé části souboru byla ve většině případů podmíněna nesprávně nastavenými technickými parametry testu. U žen testovaných v ovulační fázi menstruačního cyklu jsme prokázali signifikantně vyšší efektivitu CPM mechanizmu ve srovnání s muži. Funkce TS se mezi oběma pohlavími významně nelišila. Významný vliv věku na efektivitu CPM ani TS mechanizmu nebyl ve sledovaném souboru prokázán. Závěr: Provedená studie ověřila použitelnost zvolených algoritmů dynamického testování senzitivity a prokázala antinociceptivní nastavení žen v ovulační fázi menstruačního cyklu ve srovnání s muži, zatímco významný vliv věku na funkci centrálních modulačních mechanizmů algické percepce nebyl zachycen., Background: So called “dynamic quantitative sensory methods” (dQST) represent relatively new QST application which enables to objectify certain mechanisms of pain processing, e.g. central integration or descending control. Their dysfunction may contribute to the development of chronic painful conditions. dQST methods proved the potential to predict the development of chronic postoperative pain. Conditioned pain modulation (CPM) and temporal summation (TS) are the most commonly used dQST tests. Patients and methods: The CPM and TS testing was performed in a group of 77 healthy volunteers (47 women tested in the ovulatory phase of the menstrual cycle, 30 men, age range 19–73) using thermal pain stimuli. Efficiency of CPM and TS mechanism including age and gender influence was evaluated. Results: Efficient CPM was found in 84% of healthy volunteers. In remaining 16%, the inefficiency was mainly due to low intensity of testing or modulatory stimuli. Based on the temperature used, efficient TS mechanism was found in 92% or 98% of healthy individuals. Women in the ovulatory phase of the menstrual cycle showed significantly more efficient CPM comparing to men. No sex differences of TS testing were found. Age had no significant effect on the CPM or TS mechanism in our group of healthy voluteers. Conclusions: Our study has verified the applicability of CPM and TS algorithms used. Women in ovulatory phase of the menstrual cycle show increased anti-nociceptive setting comparing to men. No significant effect of age on central modulation of pain perception has been found in pain-free healthy individuals. Key words: pain perception – nociceptive pain – neuropathic pain – temporal summation – conditioned pain modulation – pain measurement – sex factors – age factors The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers., and S. Kincová, E. Vlčková, I. Šrotová, J. Raputová, J. Bednařík
In celestial mechanics interactions of radiation and small bodies in Solar system can be classified as scattering, absorption, radiation drag and thermal emission. The final one, in particular, induces important secular changes of orbits and rotation states of asteroids and meteoroids, as supported by a number of astronomical observations., Miroslav Brož., and Obsahuje seznam literatury
Following the introduction of Anguillicola crassus into Lake Balaton, by 1991 the entire eel population became infected. At the same time, marked differences existed in the prevalence and intensity of infection between different areas of the lake. The highest prevalence values occurred in the eastern basin less densely populated with eels, while in the western basin a large proportion of the fish were free of infection. Helminth-free status accompanied by thickening of the swimbladder wall developed after intensive infections. In 1991, eel mortality could be observed only in the western basin. In 1992, the number of eels with swimbladders having a thickened wall but not containing helminths increased also in the central and eastern areas of the lake. Parallel to this, a mortality less expressed than the one in 1991 occurred in the central part of the lake. By 1993, a host-parasite equilibrium had become established in Lake Balaton.
To specify the role of individual cytokines in the immune response to pyrogens, isolated and cultivated human peripheral blood mononuclear cells (PBMC) were used for the experiments. Different pyrogens (lipopolysaccharide from Escherichia coli - LPS and live Borrelia afzelii) were applied and the time course of changes in concentrations of different cytokines in the medium was followed using the ELISA method. It was found that nonstimulated human PBMC proliferate under in vitro conditions and produce IL-6, TNF-a, IL-10 and finally also IL-1b. Productions of IL-12 and INF-g are not changed. Proliferation of PBMC is potentiated after incubation with LPS or live Borrelia. PBMC stimulated by LPS increase the net production (stimulated minus unstimulated) of IL-1b and TNF-a significantly, while production of IL-6 was smaller. A delayed increase in the production of IL-10 was also observed. Productions of IL-12 and INF-g were not influenced. In contrast to LPS, stimulation of PBMC with live Borrelia, increases also the production of IL-12 and IFN-g, besides IL-1b, TNF-a, IL-6 and IL-10. Productions of IL-1b, IL-6 and TNFa increased immediately after incubation with both LPS and Borrelia, while productions of IL-12 and INF-g begin to increase 8 hours and production of IL-10 12 hours after stimulation. Data indicate that stimulation with different pyrogens may activate the cells of the immune cascade in a different way. Stimulation of BPMC by LPS seems to activate the initial steps of the immune response (macrophages and granulocytes) only, while infection with live Borrelia also stimulates the later phase of the immune response, probably due to effect of initially produced cytokines., L. Janský, P. Reymanová, J. Kopecký., and Obsahuje bibliografii
To specify the role of individual cytokines in the immune response to pyrogens, isolated and cultivated human peripheral blood mononuclear cells (PBMC) were used for the experiments. Different pyrogens (lipopolysaccharide from Escherichia coli - LPS and live Borrelia afzelii) were applied and the time course of changes in concentrations of different cytokines in the medium was followed using the ELISA method. It was found that nonstimulated human PBMC proliferate under in vitro conditions and produce IL-6, TNF-a, IL-10 and finally also IL-1b. Productions of IL-12 and INF-g are not changed. Proliferation of PBMC is potentiated after incubation with LPS or live Borrelia. PBMC stimulated by LPS increase the net production (stimulated minus unstimulated) of IL-1b and TNF-a significantly, while production of IL-6 was smaller. A delayed increase in the production of IL-10 was also observed. Productions of IL-12 and INF-g were not influenced. In contrast to LPS, stimulation of PBMC with live Borrelia, increases also the production of IL-12 and IFN-g, besides IL-1b, TNF-a, IL-6 and IL-10. Productions of IL-1b, IL-6 and TNFa increased immediately after incubation with both LPS and Borrelia, while productions of IL-12 and INF-g begin to increase 8 hours and production of IL-10 12 hours after stimulation. Data indicate that stimulation with different pyrogens may activate the cells of the immune cascade in a different way. Stimulation of BPMC by LPS seems to activate the initial steps of the immune response (macrophages and granulocytes) only, while infection with live Borrelia also stimulates the later phase of the immune response, probably due to effect of initially produced cytokines., L. Janský, P. Reymanová, J. Kopecký., and Obsahuje bibliografii
Comparison of the dynamics and antigen recognition profiles of IgG3 following immunisation with larval crude extracts (LCE) and excretory-secretory (ES) products from muscle larvae of different species of Trichinella (T. spiralis, T. nativa, T. britovi, T. nelsoni and genotype T6) was made in BALB/c mice. High levels of IgG3 response were obtained in ELISA following immunisation with LCE from all species with maximum levels achieved between days 59 and 64 post-immunisation (p.i.) and maintained up to the limit of the observation (day 164). Antigen recognition profiles as measured by western-blot showed dense and numerous bands in the range 45-64 kDa that were consistent from week 5lh with variation in epitope recognition among the different species. Following immunisation with ES antigens a significant decrease in IgG3 response was observed for all species especially for T. nativa in comparison to LCE. Antigen recognition on ĽS antigens showed three main bands in the range of 45-60 kDa for all species excepting T. nelsoni and T. britovi where an additional band was also present. These results clearly show that IgG3 epitopes are more abundanl in somatic (LCE) than in ES products of Trichinella muscle larvae and that quantitative as well as qualitative variations exist among different species.