79 research outputs found

    Catalytic performance of commercial Cu-ZSM-5 zeolite modified by desilication in NH3-SCR and NH3-SCO processes

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    [EN] In the presented manuscript an influence of the mesoporosity generation in commercial ZSM-5 zeolite on its catalytic performance in two environmental processes, such as NO reduction with ammonia (NH3SCR, Selective Catalytic Reduction of NO with NH3) and NH3 oxidation (NH3-SCO, Selective Catalytic Oxidation of NH3) was examined. Micro-mesoporous catalysts with the properties of ZSM-5 zeolite were obtained by desilication with NaOH and NaOH/TPAOH (tetrapropylammonium hydroxide) mixture with different ratios (TPA+/OH- = 0.2, 0.4, 0.6, 0.8 and infinity) and for different durations (1, 2, 4 and 6 h). The results of the catalytic studies (over the Cu-exchanged samples) showed higher activity of this novel mesostructured group of zeolitic materials. Enhanced catalytic performance was related to the generated mesoporosity (improved Hierarchy Factor (HF) of the samples), that was observed especially with the use of Pore Directing Agent (PDA) additive, TPAOH. Applied desilication conditions did not influence significantly the crystallinity of the samples (X-ray diffraction analysis (XRD)), despite the treatment for 6 h in NaOH solution, which was found to be too severe to preserve the zeolitic properties of the samples. The modified porous structure and accessibility of acid sites (increased surface acidity determined by temperature programmed desorption of ammonia (NH3-TPD)) influenced the red-ox properties of copper species introduced by ion-exchange method (temperature programmed reduction with hydrogen (H-2-TPR). Increased acidity of the micro-mesoporous samples, as well as the content of easily reducible copper species resulted in a significant improvement of Cu-ZSM-5 catalytic efficiency in the NH3-SCR and NH3-SCO processes. (C) 2017 Elsevier Inc. All rights reserved.This work was supported by the National Science Center under grant no. 2011/03/N/ST5/04820. Part of the research was carried out with the equipment purchased thanks to the financial support of the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. POIG.02.01.00-12-023/08). U. D. acknowledges to Spanish Government by the funding (MAT2014-52085-C2-1-P).Rutkowska, M.; Pacia, I.; Basag, S.; Kowalczyk, A.; Piwowarska, Z.; Duda, M.; Tarach, K.... (2017). Catalytic performance of commercial Cu-ZSM-5 zeolite modified by desilication in NH3-SCR and NH3-SCO processes. Microporous and Mesoporous Materials. 246:193-206. https://doi.org/10.1016/j.micromeso.2017.03.017S19320624

    Vascular ATGL-dependent lipolysis and the activation of cPLA2-PGI2 pathway protect against postprandial endothelial dysfunction

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    Adipose triglyceride lipase (ATGL) is involved in lipolysis and displays a detrimental pathophysiological role in cardio-metabolic diseases. However, the organo-protective effects of ATGL-induced lipolysis were also suggested. The aim of this work was to characterize the function of lipid droplets (LDs) and ATGL-induced lipolysis in the regulation of endothelial function. ATGL-dependent LDs hydrolysis and cytosolic phospholipase A2(cPLA2)A_{2} (cPLA_{2})-derived eicosanoids production were studied in the aorta, endothelial and smooth muscle cells exposed to exogenous oleic acid (OA) or arachidonic acid (AA). Functional effects of ATGL-dependent lipolysis and subsequent activation of cPLA2/PGI2cPLA_{2}/PGI_{2} pathway were also studied in vivo in relation to postprandial endothelial dysfunction. The formation of LDs was invariably associated with elevated production of endogenous AA-derived prostacyclin PGI2PGI_{2}. In the presence of the inhibitor of ATGL or the inhibitor of cytosolic phospholipase A2A_{2}, the production of eicosanoids was reduced, with a concomitant increase in the number of LDs. OA administration impaired endothelial barrier integrity in vitro that was further impaired if OA was given together with ATGL inhibitor. Importantly, in vivo, olive oil induced postprandial endothelial dysfunction that was significantly deteriorated by ATGL inhibition, cPLA2cPLA_{2} inhibition or by prostacyclin (IP) receptor blockade. In summary, vascular LDs formation induced by exogenous AA or OA was associated with ATGL- and cPLA2cPLA_{2}-dependent PGI2PGI_{2} production from endogenous AA. The inhibition of ATGL resulted in an impairment of endothelial barrier function in vitro. The inhibition of ATGLcPLA2PGI2ATGL-cPLA_{2}-PGI_{2} dependent pathway resulted in the deterioration of endothelial function upon exposure to olive oil in vivo. In conclusion, vascular ATGLcPLA2PGI2ATGL-cPLA_{2}-PGI_{2} dependent pathway activated by lipid overload and linked to LDs formation in endothelium and smooth muscle cells has a vasoprotective role by counterbalancing detrimental effects of lipid overload on endothelial function

    The effects of electrical hippocampal kindling of seizures on amino acids and kynurenic acid concentrations in brain structures

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    Our study demonstrated that the development of seizures during the electrically induced kindling of seizures is associated with significant changes in the concentration of kynurenic acid (KYNA) and its precursor, tryptophan (TRP). The primary finding of our study was an increase in KYNA levels and the KYNA/TRP ratio (a theoretical index of activity of the kynurenine pathway) in the amygdala and hippocampus of kindled animals. We also found decreases in the concentration of tryptophan in the hippocampus and prefrontal cortex. Changes in the concentration of KYNA and TRP in the amygdala were accompanied by a significant decrease in γ-Aminobutryic Acid (GABA) levels and an increase in the glutamate/GABA ratio. Moreover, we found a significant negative correlation between the local concentrations of KYNA and glutamate in the amygdala of kindled rats. However, there were no changes in the local concentrations of the following amino acids: glutamate, aspartate, glutamine, glycine, taurine and alanine. In conclusion, these new results suggest a modulatory influence of KYNA on the process of epileptogenesis, characterized by a negative relationship between the KYNA and glutamate systems in the amygdala

    Epilepsy and Psychiatric Comorbidities: Drug Selection.

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    Purpose of review The pharmacological treatment of patients with epilepsy and psychiatric comorbidities may sometimes represent a therapeutic challenge. This review is focused on the pharmacological management of patients with epilepsy and psychiatric problems in terms of rationalization of the antiepileptic drug (AED) treatment and the pharmacological management of the most clinically relevant psychiatric comorbidities, namely mood and anxiety disorders, psychoses, and attention deficit hyperactivity disorder (ADHD). Recent findings Up to 8% of patients with drug-resistant epilepsy develop treatment-emergent psychiatric adverse events of AED regardless of the mechanism of action of the drug and this is usually related to an underlying predisposition given by the previous psychiatric history and the involvement of mesolimbic structures. Careful history taking, periodic screening for mood and anxiety disorders, low starting doses, and slow titration schedules can reduce the possibility of AED-related problems. A pragmatic checklist for the pharmacological management of patients with epilepsy and psychiatric disorders is presented. Summary patients should be informed of potential behavioral effects of AEDs but no drugs should be excluded a priori. Any psychiatric comorbidity should be addressed in the appropriate setting and full remission and recovery should always represent the first goal of any therapeutic intervention. Neurologists should be aware of the side effects of major psychotropic drug classes in order to fully counsel their patients and other health professionals involved

    Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study

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    This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.COST (European Cooperation in Science and Technology)Portuguese Foundation for Science and TechnologyNational Research Fund of Luxembourg (FNR)China Scholarship Council (CSC)BOKU Core Facilities Multiscale ImagingDeutsche Forschungsgemeinschaft (DFG, German Research Foundation

    Ocena zanieczyszczenia środowiska związkami EDCs pochodzącymi z przedmiotów codziennego użytku

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    Endocrine-disrupting compounds (EDCs) are a specific category of chemicals that attracted a great deal of public and scientific attention in the past few decades. They are proved to interfere with the endocrine system, and thus affect the growth, reproduction, homeostasis and metabolism of living organisms. They appear as a threat not only for humans but also for the wildlife. EDCs are present in plastics such as plastic food packaging, detergents, pesticides, fire retardants, heavy metals, pharmaceuticals. They are also components of personal care products, for example cosmetics like creams, soaps or UV filters, oral contraceptives, analgesics and many more. They are not always detected and eliminated in sewage treatment plants and because of that they get to the environment and with the running water into the households. In order to eliminate different contaminants, appropriate techniques have to be chosenZwiązki modulujące pracę hormonów estrogenowych są grupą związków chemicznych, które przez ostatnich kilka dekad zwróciły uwagę zarówno społeczeństwa, jak i naukowców. Dowiedziono, że substancje te ingerują w prawidłową pracę układu hormonalnego i zaburzają rozwój, reprodukcję, homeostazę i metabolizm żywych organizmów. Zagrażają nie tylko ludziom, ale także wszystkim żywym organizmom. Są obecne w: plastikach, między innymi plastikowych opakowaniach na żywność, detergentach, pestycydach, tworzywach ognioodpornych, metalach ciężkich, a także farmaceutykach i produktach codziennej higieny, takich jak kosmetyki - kremy czy mydła, filtry UV, doustne środki antykoncepcyjne i przeciwbólowe, a także w wielu innych produktach. Nie zawsze są wykryte i usunięte ze ścieków, a w ten sposób dostają się do środowiska i gospodarstw domowych wraz z bieżącą wodą. W celu eliminacji powyższych substancji zanieczyszczających muszą być użyte odpowiednie techniki oczyszczania ścieków

    Phosphite fertilisers as inhibitors of Hymenoscyphus fraxineus (anamorph Chalara fraxinea) growth in tests in vitro

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    This study is designed to test the potential for reducing the growth of the mycelium of the fungus Hymenoscyphus fraxineus (anamorph Chalara fraxinea) by using phosphite preparations at various concentrations in vitro. The study shows that adding pure phosphite to potato dextrose agar media inhibits the development of the fungus, but if the preparation is applied in the form of ammonium phosphite (Actifos), the growth of fungus will be accelerated. Probably the addition of nitrogen contained in the product Actifos has positive effect on the mycelial growth, but pure phosphite restricts its development. These studies are preliminary and only show the potential use of phosphite to reduce the development of H. fraxineus; however, to completely confirm its operation, further research is needed in this area

    Désorption thermique d'oxydes de rhénium et d'oxygène atomique à partir d'oxygène adsorbé sur des alliages platine-rhénium

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    Des experiences de desorption thermique programmée mettent en évidence une hétérogénéité de composition superficielle induite par l'oxygène dans des alliages platine-rhénium. Il apparaît des plages de rhénium pur A forte chaleur d'adsorption de l'oxygène voisinant avec des plages d'alliages où l'énergie d'adsorption est plus faible, ce qui conduit A une vitesse d'oxydation plus importante étudiée par ailleurs
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