938 research outputs found

    Key hormonal components regulate agronomically important traits in barley

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    Marek Marzec is supported by scholarships funded by the Ministry of Science and Higher Education (424/STYP/10/2015 and DN/MOB/245/IV/2015). Ahmad M. Alqudah supported by Leibniz Institute of Plant Genetics and Crop Plant Research (IPK).The development and growth of plant organs is regulated by phytohormones, which constitute an important area of plant science. The last decade has seen a rapid increase in the unravelling of the pathways by which phytohormones exert their influence. Phytohormones function as signalling molecules that interact through a complex network to control development traits. They integrate metabolic and developmental events and regulate plant responses to biotic and abiotic stress factors. As such, they influence the yield and quality of crops. Recent studies on barley have emphasised the importance of phytohormones in promoting agronomically important traits such as tillering, plant height, leaf blade area and spike/spikelet development. Understanding the mechanisms of how phytohormones interact may help to modify barley architecture and thereby improve its adaptation and yield. To achieve this goal, extensive functional validation analyses are necessary to better understand the complex dynamics of phytohormone interactions and phytohormone networks that underlie the biological processes. The present review summarises the current knowledge on the crosstalk between phytohormones and their roles in barley development. Furthermore, an overview of how phytohormone modulation may help to improve barley plant architecture is also provided.MNiS

    Ferroelectric liquid crystal for use in a new generation of LCDs

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    The key to improvements in liquid crystalline displays lies in the continuous synthesis and studies of new kinds of liquid crystalline substances. Among them, ferroelectric compounds are the subject of much attention, due to the potential progresses in switching time, colour depth, and other qualities of liquid crystal displays. In this paper we describe the research of the physical properties of 4-(2-methylbutoxy)phenyl 4-(octyloxy)-benzoate for purposes of its potential application in liquid crystal displays

    Probing the structure-function relationship of hemoglobin in living human red blood cells

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    Hemoglobin (Hb) is a key component of respiratory system and as such plays important role in human physiology. The studies of Hb's structure and functions are usually performed on cell-free protein; however, it has been shown that there are functionally relevant differences between isolated Hb and Hb present inside red blood cells (RBCs). It is clear that new experimental approaches are needed to understand the origin of these differences and to gain insight into the structure-function relationship of Hb within intact living cells. In this work we present a novel application of Resonance Raman spectroscopy to study heme active site of different forms of human Hb within living RBCs using laser excitation lines in resonance with their Soret absorption bands. These studies revealed that there are no significant changes in the disposition of the Fe-O-O fragment or the Fe-NHis linkage for Hb molecules enclosed in RBCs and these in free isolated states. However, some changes in the orientation of the heme vinyl groups were observed which might account for the differences in the protein activity and ligand affinity. This work highlights importance of protein-based studies and presents a new opportunity to translate these results to physiological cell systems

    Different route of hydroxide incorporation and thermal stability of new type of water clathrate : X-ray single crystal and Raman investigation

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    Chlormayenite Ca12Al14O32[♦4Cl2] (♦-vacancy) is partially hydrated micro porouss mineral with hydroxide groups situated at various crystallographic sites. There are few mechanisms describing its hydration. The first one assumes Cl- substitution by OH- at the center of the structural cages (W-site). The second one determines the converting a T1O4 tetrahedron to a T1O3(OH)3 octahedron due to the replacement of oxygen at the O2 site by three OH-groups according to the scheme: (O2O2- + W Cl-) → 3 × O2aOH. The third mechanism, not considered so far in the case of zeolite-like minerals, includes the hydroxide incorporation in form of hydrogarnet defect due to the arrangement of tetrahedral (OH)4 in vacant cages. This yields a strong hydrated phase containing even up to 35% of water more than in any currently known mineral applicable to Portland cement. Moreover, water molecules present in different structural cages are stable up to 355 K while dehydroxylation linked to the gradual loss of only 8% of OH- groups according to 3 O2aOH- → O2O2- + W OH- + gH2O occurs at temperature range from 355 K to 598 K

    Selective ammonia oxidation over ZSM-5 zeolite: Impact of catalyst's support porosity and type of deposited iron species

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    [EN] In the presented studies an influence of different parameters, such as zeolite sample porosity, form of used iron source ([Fe-3(OAc)(6)O(H2O)(3)](+)oligocations or FeSO4 solutions) and method of iron species deposition (ion-exchange, impregnation), on the catalytic activity in the process of the selective catalytic oxidation of ammonia (NH3-SCO) was studied. Conventional and mesoporous ZSM-5 zeolites, obtained by desilication and modified with iron species, were analysed with respect to their textural, surface and crystalline properties (N-2-sorption, HRTEM, SEM, XRD) as well as the form of introduced Fe species (UV-vis-DRS). Ion-exchange with [Fe-3(OAc)(6)O (H2O)(3)](+) oligocations and impregnation with these oligocations and FeSO4 solutions were found as the most effective methods of the zeolite samples activation for NH3-SCO.This work was carried out in the frame of project No. 0670/IP3/2016/74 from the Polish Ministry of Science and Higher Education in the years 2016-2019. Part of the work was performed in the frame of project No. 2012/05/B/ST5/00269from the National Science Centre (Poland). U. D. acknowledges to the Spanish Government by the funding (MAT2017-82288-C2-1-P). The authors would like to acknowledge to Clariant Company for the providing of the HMFI zeolite material for the presented research.Borcuch, A.; Rutkowska, M.; Marzec, A.; Kowalczyk, A.; Michalik, M.; Moreno, J.; Díaz Morales, UM.... (2020). Selective ammonia oxidation over ZSM-5 zeolite: Impact of catalyst's support porosity and type of deposited iron species. Catalysis Today. 348:223-229. https://doi.org/10.1016/j.cattod.2019.08.054S223229348Weckhuysen, B. M., & Yu, J. (2015). Recent advances in zeolite chemistry and catalysis. Chemical Society Reviews, 44(20), 7022-7024. doi:10.1039/c5cs90100fVerboekend, D., & Pérez-Ramírez, J. (2011). Design of hierarchical zeolite catalysts by desilication. Catalysis Science & Technology, 1(6), 879. doi:10.1039/c1cy00150gRutkowska, M., Pacia, I., Basąg, S., Kowalczyk, A., Piwowarska, Z., Duda, M., … Chmielarz, L. (2017). Catalytic performance of commercial Cu-ZSM-5 zeolite modified by desilication in NH 3 -SCR and NH 3 -SCO processes. Microporous and Mesoporous Materials, 246, 193-206. doi:10.1016/j.micromeso.2017.03.017Góra-Marek, K., Brylewska, K., Tarach, K. A., Rutkowska, M., Jabłońska, M., Choi, M., & Chmielarz, L. (2015). IR studies of Fe modified ZSM-5 zeolites of diverse mesopore topologies in the terms of their catalytic performance in NH3-SCR and NH3-SCO processes. Applied Catalysis B: Environmental, 179, 589-598. doi:10.1016/j.apcatb.2015.05.053Macina, D., Piwowarska, Z., Góra-Marek, K., Tarach, K., Rutkowska, M., Girman, V., … Chmielarz, L. (2016). SBA-15 loaded with iron by various methods as catalyst for DeNOx process. Materials Research Bulletin, 78, 72-82. doi:10.1016/j.materresbull.2016.02.026Rutkowska, M., Duda, M., Macina, D., Górecka, S., Dębek, R., Moreno, J. M., … Chmielarz, L. (2019). Mesoporous Beta zeolite functionalisation with FexCry oligocations; catalytic activity in the NH3SCO process. Microporous and Mesoporous Materials, 278, 1-13. doi:10.1016/j.micromeso.2018.11.003Miller, J. T., Glusker, E., Peddi, R., Zheng, T., & Regalbuto, J. R. (1998). Catalysis Letters, 51(1/2), 15-22. doi:10.1023/a:1019072631175Kowalczyk, A., Borcuch, A., Michalik, M., Rutkowska, M., Gil, B., Sojka, Z., … Chmielarz, L. (2017). MCM-41 modified with transition metals by template ion-exchange method as catalysts for selective catalytic oxidation of ammonia to dinitrogen. Microporous and Mesoporous Materials, 240, 9-21. doi:10.1016/j.micromeso.2016.11.002Chmielarz, L., & Jabłońska, M. (2015). Advances in selective catalytic oxidation of ammonia to dinitrogen: a review. RSC Advances, 5(54), 43408-43431. doi:10.1039/c5ra03218kThommes, M., Kaneko, K., Neimark, A. V., Olivier, J. P., Rodriguez-Reinoso, F., Rouquerol, J., & Sing, K. S. W. (2015). Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure and Applied Chemistry, 87(9-10), 1051-1069. doi:10.1515/pac-2014-1117Qi, G., & Yang, R. T. (2005). Selective catalytic oxidation (SCO) of ammonia to nitrogen over Fe/ZSM-5 catalysts. Applied Catalysis A: General, 287(1), 25-33. doi:10.1016/j.apcata.2005.03.00

    Micron-sized biogenic and synthetic hollow mineral spheres occlude additives within single crystals

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    Incorporating additives within host single crystals is an effective strategy for producing composite materials with tunable mechanical, magnetic and optical properties. The type of guest materials that can be occluded can be limited, however, as incorporation is a complex process depending on many factors including binding of the additive to the crystal surface, the rate of crystal growth and the stability of the additives in the crystallisation solution. In particular, the size of occluded guests has been restricted to a few angstroms – as for single molecules – to a few hundred nanometers – as for polymer vesicles and particles. Here, we present a synthetic approach for occluding micrometer-scale objects, including high-complexity unicellular organisms and synthetic hollow calcite spheres within calcite single crystals. Both of these objects can transport functional additives, including organic molecules and nanoparticles that would not otherwise occlude within calcite. Therefore, this method constitutes a generic approach using calcite as a delivery system for active compounds, while providing them with effective protection against environmental factors that could cause degradation

    Simultaneous Inhibition of mTOR-Containing Complex 1 (mTORC1) and MNK Induces Apoptosis of Cutaneous T-Cell Lymphoma (CTCL) Cells

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    BACKGROUND: mTOR kinase forms the mTORC1 complex by associating with raptor and other proteins and affects a number of key cell functions. mTORC1 activates p70S6kinase 1 (p70S6K1) and inhibits 4E-binding protein 1 (4E-BP1). In turn, p70S6K1 phosphorylates a S6 protein of the 40S ribosomal subunit (S6rp) and 4E-BP1, with the latter negatively regulating eukaryotic initiation factor 4E (eIF-4E). MNK1 and MNK2 kinases phosphorylate and augment activity of eIF4E. Rapamycin and its analogs are highly specific, potent, and relatively non-toxic inhibitors of mTORC1. Although mTORC1 activation is present in many types of malignancies, rapamycin-type inhibitors shows relatively limited clinical efficacy as single agents. Initially usually indolent, CTCL displays a tendency to progress to the aggressive forms with limited response to therapy and poor prognosis. Our previous study (M. Marzec et al. 2008) has demonstrated that CTCL cells display mTORC1 activation and short-term treatment of CTCL-derived cells with rapamycin suppressed their proliferation and had little effect on the cell survival. METHODS: Cells derived from CTCL were treated with mTORC1 inhibitor rapamycin and MNK inhibitor and evaluated for inhibition of the mTORC1 signaling pathway and cell growth and survival. RESULTS: Whereas the treatment with rapamycin persistently inhibited mTORC1 signaling, it suppressed only partially the cell growth. MNK kinase mediated the eIF4E phosphorylation and inhibition or depletion of MNK markedly suppressed proliferation of the CTCL cells when combined with the rapamycin-mediated inhibition of mTORC1. While MNK inhibition alone mildly suppressed the CTCL cell growth, the combined MNK and mTORC1 inhibition totally abrogated the growth. Similarly, MNK inhibitor alone displayed a minimal pro-apoptotic effect; in combination with rapamycin it triggered profound cell apoptosis. CONCLUSIONS: These findings indicate that the combined inhibition of mTORC1 and MNK may prove beneficial in the treatment of CTCL and other malignancies
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