Search results for "ureas"
showing 7 items of 27 documents
CeO2−x nanorods with intrinsic urease-like activity
2018
The large-scale production and ecotoxicity of urea make its removal from wastewater a health and environmental challenge. Whereas the industrial removal of urea relies on hydrolysis at elevated temperatures and high pressure, nature solves the urea disposal problem with the enzyme urease under ambient conditions. We show that CeO2−x nanorods (NRs) act as the first and efficient green urease mimic that catalyzes the hydrolysis of urea under ambient conditions with an activity (kcat = 9.58 × 101 s−1) about one order of magnitude lower than that of the native jack bean urease. The surface properties of CeO2−x NRs were probed by varying the Ce4+/Ce3+ ratio through La doping. Although La substit…
Carditis in patients with gastro-oesophageal reflux disease: results of a controlled study based on both endoscopy and 24-h oesophageal pH monitoring
2004
Summary Background : There are conflicting reports on the role of gastro-oesophageal reflux disease (GERD) and Helicobacter pylori infection in the aetiology of carditis. Aim : The role of reflux and H. pylori infection in causing carditis was assessed in 113 consecutive patients with GERD and in 25 controls. Methods : All subjects underwent endoscopy and pH test and carditis was diagnosed on biopsies taken across the squamocolumnar junction. Helicobacter pylori was assessed by histology and rapid urease test. GERD was diagnosed by endoscopic oesophagitis or abnormal pH test. Results : Carditis was detected in 53 of 71 GERD patients and in 15 of 20 controls. Among patients, 18 showed absent…
The incidence of infection, diagnosis and treatment of H. pylori in developing countries on the example of Kenya
2020
Machaj Dominik, Jastrzębska Sandra, Cyboran Katarzyna, Płaczek Alicja, Flaumenhaft Wiktoria. The incidence of infection, diagnosis and treatment of H. pylori in developing countries on the example of Kenya. Journal of Education, Health and Sport. 2020;10(3):11-17. eISSN 2391-8306. DOI http://dx.doi.org/10.12775/JEHS.2020.10.03.001 https://apcz.umk.pl/czasopisma/index.php/JEHS/article/view/JEHS.2020.10.03.001 https://zenodo.org/record/3696977 The journal has had 5 points in Ministry of Science and Higher Education parametric evaluation. § 8. 2) and § 12. 1. 2) 22.02.2019. © The Authors 2020; This article is published with open access at Licensee Open Journal Sy…
Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.
1993
The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to …
The interactive effects of various nitrogen fertiliser formulations applied to urine patches on nitrous oxide emissions in grassland
2017
AbstractPasture-based livestock agriculture is a major source of greenhouse gas (GHG) nitrous oxide (N2O). Although a body of research is available on the effect of urine patch N or fertiliser N on N2O emissions, limited data is available on the effect of fertiliser N applied to patches of urinary N, which can cover up to a fifth of the yearly grazed area. This study investigated whether the sum of N2O emissions from urine and a range of N fertilisers, calcium ammonium nitrate (CAN) or urea ± urease inhibitor ± nitrification inhibitor, applied alone (disaggregated and re-aggregated) approximated the N2O emission of urine and fertiliser N applied together (aggregated). Application of fertili…
Helicobacter pylori in the dental plaque : is it of diagnostic value for gastric infection?
2006
Aim: The aim of the present study was the assessment of association of helicobacter pylori of dental plaque and stomach in a more homogenous population and also to determine the diagnostic value of dental plaque for gastric infection. Materials and Methods: Based on the results of Rapid urease test (RUT) on specimens from gastric antrum, 88 patients with symptoms of dyspepsia were assigned into two groups of infected and non-infected with helicobacter pylori. Supragingival plaque samples were collected from mandibular first and second molar area using and sterile curette and were investigated using RUT. Statistical analysis of data was performed using chi-square test and independent t-test.…
Dual Enzyme-Triggered Controlled Release on Capped Nanometric Silica Mesoporous Supports
2012
The development of nanoscopic hybrid materials equipped with “molecular gates” showing the ability of releasing target entrapped guests upon the application of an external trigger has attracted great attention and has been extensively explored during recent years.1 These nanodevices are composed of two subunits, namely, a suitable support and certain capping entities grafted on the surface of the scaffolding.2 The support is used as a suitable reservoir in which certain chemicals can be stored whereas the molecules grafted in the outer surface act as a “gate” and can control the release of the entrapped molecules at will. Both components are carefully selected and arranged in order to achie…