53 research outputs found
Selective catalytic oxidation (SCO) of ammonia to nitrogen over hydrotalcite originated Mg-Cu-Fe mixed metal oxides
Mg-Cu-Fe oxide systems, obtained from hydrotalcite-like precursors, were tested as catalysts for the selective catalytic oxidation (SCO) of ammonia. Copper containing catalysts were active in low-temperature SCO processes; however, their selectivity to nitrogen significantly decreased at higher temperatures. The optimum composition of the catalyst to guarantee high activity and selectivity to N2 was proposed. Temperature-programmed experiments, SCO catalytic tests performed with various contact times and additional tests on the samples in the selective catalytic reduction of NO with ammonia showed that the SCO process over the studied calcined hydrotalcites proceeds according to the internal SCR mechanism and oxidation of ammonia to NO is a rate-determining step in the low-temperature range
Thermal transformations of Cu–Mg (Zn)–Al(Fe) hydrotalcite-like materials into metal oxide systems and their catalytic activity in selective oxidation of ammonia to dinitrogen
Layered double hydroxides (LDHs) containing
Mg^{2+}, Cu^{2+} or Zn^{2+} cations in the Me^{II} positions and Al^{3+}
and Fe^{3+} in the Me^{III} positions were synthesized by co-
precipitation method. Detailed studies of thermal trans-
formation of obtained LDHs into metal oxide systems were
performed using high temperature X-ray diffraction in
oxidising and reducing atmosphere, thermogravimetry
coupled with mass spectrometry and temperature-pro-
grammed reduction. The LDH samples calcined at 600 and
900 °C were tested in the role of catalysts for selective
oxidation of ammonia into nitrogen and water vapour. It
was shown that all copper congaing samples presented high
catalytic activity and additionally, for the Cu–Mg–Al and
Cu–Mg–Fe hydrotalcite samples calcined at 600 °C rela-
tively high stability and selectivity to dinitrogen was
obtained. An increase in calcination temperature to 900 °C
resulted in a decrease of their catalytic activity, possibly
due to formation of well-crystallised metal oxide phase which are less catalytically active in the process of selective oxidation of ammonia
Hydrotalcite derived (Cu, Mn)-Mg-Al metal oxide systems doped with palladium as catalysts for low-temperature methanol incineration
Hydrotalcite derived (Cu, Mn)–Mg–Al mixed metal oxides, synthesized by coprecipitation method, were found to be effective catalysts for methanol incineration. Copper and/or manganese oxides deposited on commercial γ-Al2O3 and MgO were used as the reference catalysts. Cu–Mg–Al–O mixed oxide system was found to be the most active catalysts in a series of the hydrotalcite originated metal oxides and supported samples. On the other hand, copper deposited on Al2O3 and MgO supports were significantly less active than the hydrotalcite derived catalysts. Activity of the catalysts was improved by deposition of small amount of palladium (0.5 wt.%). Temperature-programmed surface reaction method (CH3OH-TPSR) and in situ Fourier-transform infrared spectroscopy (FT-IR) were employed to study the species formed on the catalyst surface during the process of methanol oxidation
Serological Survey of \u3ci\u3eLeptospira\u3c/i\u3e Infection in Arabian Horses in Poland
Leptospirosis is one of the most common zoonotic infections worldwide, including in most livestock, some companion animals, horses, wildlife, and humans. Epidemiological estimation of its prevalence in all species is difficult due to the variety of clinical presentations and challenges regarding laboratory diagnosis. The purpose of this study was to measure the seroprevalence of leptospiral infection in Arabian horses kept in the largest breeding farms in Poland, representing over 15% of the Polish Arabian horse population. Leptospira antibodies were detected by MAT (cut-off 1:100) in 33.2% of serum samples (204 of 615 animals) (CI 95%: 29.6–37.0%), most frequently reacting with the serovar Grippotyphosa, similar to previous reports in populations of randomly selected horses. These results indicated high Leptospira seropositivity, thus, although any form of clinical leptospirosis is rare, it may be postulated that the leptospiral exposure is widespread
Biopsy and tracheobronchial aspirates as additional tools for the diagnosis of bovine tuberculosis in living European bison (bison bonasus)
CITATION: Didkowska, Anna et al. 2020. Biopsy and tracheobronchial aspirates as additional tools for the diagnosis of bovine tuberculosis in living European bison (bison bonasus). Animals, 10(11):2017, doi:10.3390/ani10112017.The original publication is available at: https://www.mdpi.comENGLISH ABSTRACT: The diagnosis of bovine tuberculosis (BTB) in living wildlife remains a complex problem,
and one of particular importance in endangered species like European bison (Bison bonasus). To identify
infection and avoid the unnecessary culling of such valuable individuals, current best practice
requires the collection and culture of material from living animals, as mycobacteria isolation
remains the gold standard in BTB diagnosis. However, such isolation is challenging due to the
need for the immobilization and collection of appropriate clinical material, and because of the
sporadic shedding of mycobacteria. In the present study, we evaluated the potential of sampling
for the detection of BTB in a group of seven living European bison suspected of being infected
with Mycobacterium caprae. The specimens were collected both as swabs from the nasal and
pharyngeal cavities, tracheobronchial aspirates (TBA), ultrasound-guided biopsies from lateral
retropharyngeal lymph nodes, and post mortem, from mandibular, retropharyngeal and mediastinal
lymph nodes. Clinical samples were tested for mycobacterial species via mycobacteriological culture
and PCR. M. caprae was isolated from collected material in two out of four living infected individuals
(TBA, biopsy) and mycobacterialDNAwas detected in three out of four (TBA, pharyngeal swab) bison.
This is the first report of isolation of M. caprae in living European bison. Our findings demonstrate the
value of diagnostic tests based on both molecular testing and culture in European bison and confirm
the respiratory shedding of viable M. caprae in this host species.Publisher's versio
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