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2632. Ascorbate plays a key role in alleviating low temperature-induced oxidative stress in Arabidopsis
- Creator:
- Wang, L. Y., Zhang, Q. Y., Wang, F., Meng, X., and Meng, Q. W.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, Arabidopsis thaliana, ascorbate, chilling stress, photoinhibition, reactive oxygen species, 2, and 58
- Language:
- Multiple languages
- Description:
- Low temperature has a negative impact on plant cells and results in the generation of reactive oxygen species (ROS). In order to study the role of ascorbate under chilling stress, the response of an ascorbate-deficient Arabidopsis thaliana mutant vtc2-1 to low temperature (2°C) was investigated. After chilling stress, vtc2-1 mutants exhibited oxidative damage. An increase in the H2O2 generation and the production of thiobarbituric acid reactive substances (TBARS), and a decrease in chlorophyll content, the maximal photochemical efficiency of PSII (Fv/Fm) and oxidizable P700 were also noted. The ratio of ascorbate/dehydroascorbate and reduced glutathione/oxidzed glutathione in the vtc2-1 mutants were reduced, compared with the wild type (WT) plants. The activities of antioxidant enzymes, such as catalase (CAT) and ascorbate peroxidase (APX), and soluble antioxidants were lower in the vtc2-1 mutants than those in WT plants. These results suggested that the ascorbate-deficient mutant vtc2-1 was more sensitive to chilling treatment than WT plants. The low temperature-induced oxidative stress was the major cause of the decrease of PSII and PSI function in the vtc2-1 mutants. Ascorbate plays a critical role of defense without which the rest of the ROS defense network is unable to react effectively., L. Y. Wang ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2633. Asférické brýlové čočky
- Creator:
- Mikš, Antonín
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Czech
- Description:
- The theory of third-order aberrations of the system rotary symmetrical aspheric thin lenses and the relations for calculation of the shape rotary symmetrical aspheric spectacle lenses with zero astigmatism are stated. A comparison the possibility of the aspheric and spherical spectacle lenses is presented. and Je uvedena teorie aberací 3. řádu soustavy tenkých rotačně symetrických asférických čoček. Jsou odvozeny vztahy pro výpočet tvaru rotačně symetrické asférické brýlové čočky s korigovaným astigmatismem a je provedeno srovnání se sférickou brýlovou čočkou.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2634. Ash characteristic in co - combustion of coal with wood residue, sewage sludge and municipal waste
- Creator:
- Vladimír Tomášek, Ondřej Šustai, Jana Seidlerová, Zdeněk Klika, Stach, Martin, Zdeněk Weiss, and Václav Roubíček
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, uhlí, popílky, skenovací elektronová mikroskopie, coal, fly ash, scanning electron microscopy, bottom ash, X-ray microanalysis, 7, and 551
- Language:
- English
- Description:
- Samples of bottom ash and fly ash coming from the combustion of lignite with the addition of limestone, from the cocombustion of lignite and wood residue with limestone and from co-combustion of lignite, wood residue, biological sludges from the waste water treatment plant and municipal waste as well with the addition of limestone were examined. Scanning electron microscopy with X-ray microanalyser were used for study of morphology and chemical composition of ash particles. The results were compared with average composition of bottom ashes, fly ashes and input materials found by X-ray fluorescence spectrometry and with phase composition found by X-ray diffraction method. There were proved no significant differences in the character and the structure of individual samples coming from various regimes of combustion., Vladimír Tomášek, Ondřej Šustai, Jana Seidlerová, Zdeněk Klika, Martin Stach, Zdeněk Weiss and Václav Roubíček., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2635. Asiatic acid induces mitochondrial apoptosis via inhibition of JAK2/STAT3 signalling pathway in human osteosarcoma
- Creator:
- Yan, B. F., Chen, X., Liu, J., Liu, S. J., Zhang, J. Z., Zeng, Q. Q., and Duan, J. A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- osteosarcoma, asiatic acid, mitochondrial apoptosis, and JAK2/STAT3/MCL-1
- Language:
- English
- Description:
- Osteosarcoma (OS), a severe malignant bone tumour, usually occurs in adolescents and children and has a poor prognosis. Asiatic acid (AA), an active component isolated from Centella asiatica (L.) Urb., exhibits appreciable anti-oxidant and anti-tumour activities. So far, the effects and underlying mechanisms of AA against OS have not been clarified. Here, we explored the anti-tumour effects of AA against human OS and the involved mechanism mediating its actions. To evaluate effects of AA on the cell proliferation of human OS cells, cell viability and colony formation assays were performed. Flow cytometry was used to evaluate apoptosis in OS cells exposed to AA and mitochondrial membrane potential. Western blotting and RT-PCR were applied to determine expression of the relevant proteins and their mRNA levels. Our explorations showed that AA inhibits proliferation of human OS cells in a concentration- and time-dependent manner, and induces apoptosis of OS cells by the intrinsic (mitochondrial) pathway. Importantly, we found that inhibition of the AA-induced phosphorylation of JAK2/STAT3 signalling molecules and the decrease in MCL-1 contributed to the anti-tumour efficacy of AA. Collectively, our results suggest that AA could evoke mitochondrial- induced apoptosis in human OS cells by suppression of the JAK2/STAT3 pathway and MCL-1 expression. These results strongly demonstrate that AA could be a potential anti-tumour agent for OS treatment.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2636. ASIC1a involves the acid-mediated activation of pancreatic stellate cells associated with autophagy induction
- Creator:
- Wang, Tao, Wang, Qianqian, Pan, Guixia, Jia, Guorong, Li, Xiao, Wang, Chao, Zhang, Liming, and Zuo, Changjing
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- ASIC1a, pancreatic stellate cells, activation, autophagy, and acidosis
- Language:
- English
- Description:
- The acidic tumor microenvironment (TME) of pancreatic cancer affects the physiological function of pancreatic stellate cells (PSCs), which in turn promotes cancer progression. Acid-sensing ion channel 1a (ASIC1a) is responsible for acidosis-related physiopathological processes. In this study, we investigated the effect of acid exposure on the activation and autophagy of PSCs, and the role of ASIC1a in these events. The results showed that acidic medium upregulated the expression of ASIC1a, induced PSCs activation and autophagy, which can be suppressed by inhibiting ASIC1a using PcTx1 or ASIC1a knockdown, suggesting that ASIC1a involves these two processes. In addition, the acidinduced activation of PSCs was impaired after the application of autophagy inhibitor alone or in combination with ASIC1a siRNA, meaning a connection between autophagy and activation. Collectively, our study provides evidence for the involvement of ASIC1a in the acid-caused PSCs activation, which may be associated with autophagy induction.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2637. Ásifdžahánina snacha. Rašída Džahán
- Creator:
- Marková, Dagmar
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2638. Asijská fauna v portugalských pramenech 16. století
- Creator:
- Staněk, Karel
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, 16. století, biologie, fauna, savci, portugalské staré tisky, mořeplavectví, biology, mammals, Portuguese old prints, seafaring, Portugalsko, Asie, Portugal, Asia, zámořské objevy, námořní plavby, 2, and 57/59
- Language:
- Czech
- Description:
- Tento článek přibližuje čtenáři svět prvních portugalských mořeplavců a jejich setkání s exotickou faunou Asie v 16. století. Důraz klade především na nosorožce a slona, ale neopomíjí ani další živočichy a věnuje se i původu některých drahocenných orientálních látek živočišného původu, pro Evropany dlouho neznámému. Text bohatě využívá citací z pramenů., This article presents the world of the first Portuguese navigators and their encounters with exotic Asian fauna in the 16th century. It primarily highlights the rhinoceros and elephants, but does not omit other animals. It also focuses on the sources of some valuable oriental substances of animal origin, which was unknown to Europeans for a long time., and Karel Staněk.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2639. Asijská fyzikální olympiáda
- Creator:
- Volf, Ivo and Kříž, Jan
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fyzika, mezinárodní fyzikální olympiády, physics, international physics olympiads, 6, and 53
- Language:
- Czech
- Description:
- Mezinárodní fyzikální soutěže mají již tradici po několik desítek let a účastní se jich soutěžící z mnoha zemí světa. Kromě toho postupně vznikly i tzv. zonální fyzikální soutěže, mezi něž patří např. Iberolatinskoamerická fyzikální soutěž a Asijská fyzikální olympiáda, určená pro soutěžící z Asie a Oceánie., Ivo Volf, Jan Kříž., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2640. Asijský gepard na hranici vymření
- Creator:
- Robovský, Jan
- Type:
- article, model:article, and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public