Submandibular glands in the metabolic syndrome

In addition to their stimulatory action on neuronal differentiation and survival, a variety of neurotrophic factors, such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor, exert metabotrophic effects, including improvement of glucose, lipid and energy homeostasis. It was recently reported that plasma levels of both NGF and BDNF are reduced in patients with advanced metabolic syndrome and with acute coronary syndromes, and that NGF tissue content is decreased in human atherosclerotic coronary arteries. Since NGF and BDNF are synthesized, stored, and released by submandibular salivary glands, we investigated the structure and function of these glands. Here we present our scintigraphic and echographic results of submandibular glands of patients with advanced stage of metabolic syndrome: (i) scintigraphic analysis using the radiotracer (99m)Tc-pertechnetate showed an inhibition of salivary gland excretory activity, and (ii) echographic evaluation revealed a parenchymal destruction and a prominent fibrosis of the glands. Both suggestive for the involvement of submandibular glands in decreased secretion of NGF and BDNF as implicated in the pathogenesis of metabolic syndrome.Biomedical Reviews 2007; 18: 65-67

Catalytic VOCs elimination over copper and cerium oxide modified mesoporous SBA-15 silica

[EN] Copper and cerium oxide bi-component materials with different Cu/Ce ratio were prepared using ordered SBA-15 silica as a support and compared with their bulk analogs. The samples were characterized by nitrogen physisorption, XRD, UV-Vis, FTIR, XPS, Raman spectroscopy and TPR with hydrogen. Cyclohexanol conversion was used as a catalytic test to obtain more information for the surface properties of the supported materials. The catalytic properties of the samples were studied in VOCs oxidation using toluene and ethyl acetate as probe molecules. A strong effect of mesoporous silica support and samples composition on the formation of catalytic sites was established. (C) 2012 Elsevier B.V. All rights reserved.Financial support of Bulgarian Academy of Science and National Scientific Fond of Ministry of Education Projects DTK 02/64 and ДНTC/Киtай 01/8, financial support from DGICYT in Spain (Project CTQ-2009-14495) and bilateral project Bulgarian-Spain Inter-academic Exchange Agreement (Project 2009BG0002) are acknowledged.Tsoncheva, T.; Issa, G.; Blasco Lanzuela, T.; Dimitrov, M.; Popova, M.; Hernández Morejudo, S.; Kovacheva, D.... (2013). Catalytic VOCs elimination over copper and cerium oxide modified mesoporous SBA-15 silica. Applied Catalysis A General. 453:1-12. https://doi.org/10.1016/j.apcata.2012.12.007S11245

Design Control of Copper-Doped Titania–Zirconia Catalysts for Methanol Decomposition and Total Oxidation of Ethyl Acetate

This study is focused on the design control of Cu–Zr–Ti oxide composites by the variation of the Zr/Ti ratio and the copper deposition procedure used. For the first time, these ternary composites were obtained by a combination of template-assisted hydrothermal techniques for the preparation of mesoporous ZrO2–TiO2 mixed oxides with diverse compositions, followed by the consecutive chemisorption and hydrolysis of copper ammonia complexes on them. The nitrogen physisorption, XRD, SEM, HRTEM, TPR, XPS, UV-Vis, and Raman spectroscopies were applied for the catalysts’ characterization. Methanol decomposition and the total oxidation of ethyl acetate, both of which with potential for sustainable environmental protection, were used as catalytic tests. The complex relationship between the phase composition, structure, and morphology of titania–zirconia mixed oxides and the state and catalytic behavior of the copper oxide species supported on them was investigated. In comparison with the conventional impregnation technique, the novel preparation procedure revealed the generation of more uniform and homogeneously dispersed needle-like copper oxide crystallites in the mesoporous TiO2–ZrO2 host matrix, which typically ensure improved catalytic performance. The synergistic activity between the loaded copper species and TiO2–ZrO2 support was discussed. All ternary composites exhibited superior catalytic activity in total oxidation of ethyl acetate. The specific behavior of the catalysts in methanol decomposition was related to the irreversible phase transformations by the influence of the reaction medium

Design Control of Copper-Doped Titania–Zirconia Catalysts for Methanol Decomposition and Total Oxidation of Ethyl Acetate

This study is focused on the design control of Cu–Zr–Ti oxide composites by the variation of the Zr/Ti ratio and the copper deposition procedure used. For the first time, these ternary composites were obtained by a combination of template-assisted hydrothermal techniques for the preparation of mesoporous ZrO2–TiO2 mixed oxides with diverse compositions, followed by the consecutive chemisorption and hydrolysis of copper ammonia complexes on them. The nitrogen physisorption, XRD, SEM, HRTEM, TPR, XPS, UV-Vis, and Raman spectroscopies were applied for the catalysts’ characterization. Methanol decomposition and the total oxidation of ethyl acetate, both of which with potential for sustainable environmental protection, were used as catalytic tests. The complex relationship between the phase composition, structure, and morphology of titania–zirconia mixed oxides and the state and catalytic behavior of the copper oxide species supported on them was investigated. In comparison with the conventional impregnation technique, the novel preparation procedure revealed the generation of more uniform and homogeneously dispersed needle-like copper oxide crystallites in the mesoporous TiO2–ZrO2 host matrix, which typically ensure improved catalytic performance. The synergistic activity between the loaded copper species and TiO2–ZrO2 support was discussed. All ternary composites exhibited superior catalytic activity in total oxidation of ethyl acetate. The specific behavior of the catalysts in methanol decomposition was related to the irreversible phase transformations by the influence of the reaction medium

Formation of Catalytic Active Sites in Hydrothermally Obtained Binary Ceria−Iron Oxides: Composition and Preparation Effects

A series of mesoporous cerium−iron binary oxides was prepared by a hydrothermal technique using CTAB as a template. The influence of the Fe/Ce ratio and the variations in the preparation techniques such as the type of solvent and the precipitation agent, the approach of the template release, and the temperature of calcination on the phase composition, textural, structural, surface, and redox properties of the obtained materials was studied in details by XRD, nitrogen physisorption, TPR, FTIR, UV−vis, XPS, Raman, and Moessbauer spectroscopies. The materials were tested as catalysts in methanol decomposition and total oxidation of ethyl acetate. It was assumed that the binary materials represented a complex mixture of differently substituted ceria- and hematite-like phases. Critical assessment of their formation on the base of a common mechanism scheme was proposed. This scheme declares the key role of the formation of shared Ce−O−Fe structures by insertion of Fe 3+ in the ceria lattice and further competitive compensation of the lattice charge balance by the existing in the system ions, which could be controlled by the Fe/Ce ratio and the hydrothermal synthesis procedure used. This mechanism provides proper understanding and regulation of the catalytic behavior of cerium−iron oxide composites in methanol decomposition with a potential for hydrogen production and total oxidation of ethyl acetate as a model of VOCs.Funding. This research was funded by the BIKE project, which received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 813748; project BG05M2OP001-1.002- 0019: “Clean technologies for sustainable environment − water, waste, energy for circular economy” (Clean&Circle); INFRAMAT (Research Infrastructure from National roadmap of Bulgaria), supported by contract D01-284/17.12.2019 with the Bulgarian Ministry of Education and Science; and Research Infrastructure NanoEnviCZ, supported by the Ministry of Education, Youth, and Sports of Czech Republic (no. LM2018124). Financial support Bulgarian Scientific Fund, Grant No KP06-H-29/2 is acknowledged

Pore topology control of supported on mesoporous silicas copper and cerium oxide catalysts for ethyl acetate oxidation

[EN] Copper and cerium bi-component modifications of KIT-6 were prepared by wetness impregnation technique from the corresponding nitrate precursors. Nitrogen physisorption, XRD, FTIR of adsorbed CO, UV-Vis, XPS and TPR were used for their characterization. The catalytic activity of the obtained materials was tested in ethyl acetate oxidation and compared to those achieved over SBA-15-supported catalysts. It was established that the interaction between copper and ceria species results in the formation of finely dispersed CuO nanoparticles on the ceria ones, which are stabilized by an interface layer of penetrated into the ceria lattice copper ions in different oxidative state. This process seems to be facilitated in the more opened 3D-structure of KIT-6, which provides better catalytic activity even at high Cu/Ce ratio than those observed for the SBA-15 modifications. (C) 2013 Elsevier Inc. All rights reserved.Financial support of projects BG051PO001-3.3.05-0001 "Hay kappa a (sic) O(sic)(sic)iiec", (sic)HTC/kappa(sic)Ta(sic) 01/8, CTQ2012-37925-0O3-01 (DGCYT, Spain) and bi-lateral project Bulgarian-Spain Inter-academic Exchange Agreement (Project 2009BG0002) are acknowledged.Tsoncheva, T.; Issa, G.; López Nieto, JM.; Blasco Lanzuela, T.; Concepción Heydorn, P.; Dimitrov, M.; Atanasova, G.... (2013). Pore topology control of supported on mesoporous silicas copper and cerium oxide catalysts for ethyl acetate oxidation. Microporous and Mesoporous Materials. 180:156-161. doi:10.1016/j.micromeso.2013.06.017S15616118

Silica supported copper and cerium oxide catalysts for ethyl acetate oxidation

[EN] The formation of active sites in the silica supported copper and cerium oxide hi-component catalysts for total oxidation of ethyl acetate was studied by Nitrogen physisorption, XRD, XPS, UV-Vis, Raman, FTIR of adsorbed CO spectroscopies and TPR. It was found that the interaction between the copper oxide nano-particles and the supported on the silica ceria ones is realized with the formation of interface layer of penetrated into ceria lattice copper ions in different oxidative state. This type of interaction improves the dispersion of copper oxide particles and provides higher accessibility of the reactants to the copper active sites even at low copper amount. (C) 2013 Elsevier Inc. All rights reserved.The paper is published with the support of Project No. BG051PO001-3.3-05/0001. Financial support of BAS, FNI of Bulgarian Ministry of Education, Project (sic)HTC/(sic)01/8, DGICYT in Spain (Project CTQ2012-37925-C03-01) and bilateral project Bulgarian Spain Inter-academic Exchange Agreement (Project 2009BG0002) are also acknowledged.Tsoncheva, T.; Issa, G.; Blasco Lanzuela, T.; Concepción Heydorn, P.; Dimitrov, M.; Hernández Morejudo, S.; Kovacheva, D.... (2013). Silica supported copper and cerium oxide catalysts for ethyl acetate oxidation. Journal of Colloid and Interface Science. 404:155-160. https://doi.org/10.1016/j.jcis.2013.05.005S15516040