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Artigos de revistas sobre o tema "Urea"

Autor: Grafiati

Publicado: 4 de junho de 2021

Última modificação: 25 de julho de 2025

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1

Heimer, Susan R., and Harry L. T. Mobley. "Interaction of Proteus mirabilis Urease Apoenzyme and Accessory Proteins Identified with Yeast Two-Hybrid Technology." Journal of Bacteriology 183, no. 4 (2001): 1423–33. http://dx.doi.org/10.1128/jb.183.4.1423-1433.2001.

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ABSTRACT Proteus mirabilis, a gram-negative bacterium associated with complicated urinary tract infections, produces a metalloenzyme urease which hydrolyzes urea to ammonia and carbon dioxide. The apourease is comprised of three structural subunits, UreA, UreB, and UreC, assembled as a homotrimer of individual UreABC heterotrimers (UreABC)3. To become catalytically active, apourease acquires divalent nickel ions through a poorly understood process involving four accessory proteins, UreD, UreE, UreF, and UreG. While homologues of UreD, UreF, and UreG have been copurified with apourease, it rema

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2

Voland, Petra, David L. Weeks, Elizabeth A. Marcus, Christian Prinz, George Sachs, and David Scott. "Interactions among the sevenHelicobacter pyloriproteins encoded by the urease gene cluster." American Journal of Physiology-Gastrointestinal and Liver Physiology 284, no. 1 (2003): G96—G106. http://dx.doi.org/10.1152/ajpgi.00160.2002.

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Survival of Helicobacter pylori in acid depends on intrabacterial urease. This urease is a Ni2+-containing oligomeric heterodimer. Regulation of its activity and assembly is important for gastric habitation by this neutralophile. The gene complex encodes catalytic subunits ( ureA/B), an acid-gated urea channel ( ureI), and accessory assembly proteins ( ureE–H). With the use of yeast two-hybrid analysis for determining protein-protein interactions, UreF as bait identified four interacting sequences encoding UreH, whereas UreG as bait detected five UreE sequences. These results were confirmed by

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3

Sangari, Félix J., Asunción Seoane, María Cruz Rodríguez, Jesús Agüero, and Juan M. García Lobo. "Characterization of the Urease Operon of Brucella abortus and Assessment of Its Role in Virulence of the Bacterium." Infection and Immunity 75, no. 2 (2006): 774–80. http://dx.doi.org/10.1128/iai.01244-06.

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ABSTRACT Most members of the genus Brucella show strong urease activity. However, the role of this enzyme in the pathogenesis of Brucella infections is poorly understood. We isolated several Tn5 insertion mutants deficient in urease activity from Brucella abortus strain 2308. The mutations of most of these mutants mapped to a 5.7-kbp DNA region essential for urease activity. Sequencing of this region, designated ure1, revealed the presence of seven open reading frames corresponding to the urease structural proteins (UreA, UreB, and UreC) and the accessory proteins (UreD, UreE, UreF, and UreG).

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4

Lisnyak, Yu. V., and AV Martynov. "STRUCTURAL ORGANIZATION OF BACTERIAL UREASES." Annals of Mechnikov Institute, no. 3 (November 18, 2016): 22–30. https://doi.org/10.5281/zenodo.167426.

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This brief review concerns the basic principles of structural organization of multi-subunit bacterial ureases and formation of their quaternary structure. Urease is a nickel-containing enzyme (urea amidohydrolase, ЕС 3.5.1.5) that catalyses the hydrolysis of urea to get ammonia and carbamate which then decomposes with water to get ammonia and carbon dioxide. Urease is produced by bacteria, fungi, yeast and plants. On the basis of similarities in amino acid sequences, ureases assumed to have a similar structure and conservative catalytic mechanism. Within past two decades bacterial ureases have

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5

Yuen, Man Hon, Yu Hang Fong, Yap Shing Nim, Pak Ho Lau, and Kam-Bo Wong. "Structural insights into how GTP-dependent conformational changes in a metallochaperone UreG facilitate urease maturation." Proceedings of the National Academy of Sciences 114, no. 51 (2017): E10890—E10898. http://dx.doi.org/10.1073/pnas.1712658114.

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The ability of metallochaperones to allosterically regulate the binding/release of metal ions and to switch protein-binding partners along the metal delivery pathway is essential to the metallation of the metalloenzymes. Urease, catalyzing the hydrolysis of urea into ammonia and carbon dioxide, contains two nickel ions bound by a carbamylated lysine in its active site. Delivery of nickel ions for urease maturation is dependent on GTP hydrolysis and is assisted by four urease accessory proteins UreE, UreF, UreG, and UreH(UreD). Here, we determined the crystal structure of the UreG dimer from Kl

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6

Scott, David R., Elizabeth A. Marcus, Yi Wen, Siddarth Singh, Jing Feng, and George Sachs. "Cytoplasmic Histidine Kinase (HP0244)-Regulated Assembly of Urease with UreI, a Channel for Urea and Its Metabolites, CO2, NH3, and NH4+, Is Necessary for Acid Survival of Helicobacter pylori." Journal of Bacteriology 192, no. 1 (2009): 94–103. http://dx.doi.org/10.1128/jb.00848-09.

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ABSTRACT Helicobacter pylori colonizes the normal human stomach by maintaining both periplasmic and cytoplasmic pH close to neutral in the presence of gastric acidity. Urease activity, urea flux through the pH-gated urea channel, UreI, and periplasmic α-carbonic anhydrase are essential for colonization. Exposure to pH 4.5 for up to 180 min activates total bacterial urease threefold. Within 30 min at pH 4.5, the urease structural subunits, UreA and UreB, and the Ni2+ insertion protein, UreE, are recruited to UreI at the inner membrane. Formation of this complex and urease activation depend on e

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7

Kasatkina, Svetlana O., Kirill K. Geyl, Sergey V. Baykov, Mikhail S. Novikov, and Vadim P. Boyarskiy. "“Urea to Urea” Approach: Access to Unsymmetrical Ureas Bearing Pyridyl Substituents." Advanced Synthesis & Catalysis 364, no. 7 (2022): 1295–304. http://dx.doi.org/10.1002/adsc.202101490.

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8

Masepohl, Bernd, Björn Kaiser, Nazila Isakovic, Cynthia L. Richard, Robert G. Kranz, and Werner Klipp. "Urea Utilization in the Phototrophic BacteriumRhodobacter capsulatus Is Regulated by the Transcriptional Activator NtrC." Journal of Bacteriology 183, no. 2 (2001): 637–43. http://dx.doi.org/10.1128/jb.183.2.637-643.2001.

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ABSTRACT The phototrophic nonsulfur purple bacteriumRhodobacter capsulatus can use urea as a sole source of nitrogen. Three transposon Tn5-induced mutations (Xan-9, Xan-10, and Xan-19), which led to a Ure−phenotype, were mapped to the ureF and ureCgenes, whereas two other Tn5 insertions (Xan-20 and Xan-22) were located within the ntrC and ntrB genes, respectively. As in Klebsiella aerogenes and other bacteria, the genes encoding urease (ureABC) and the genes required for assembly of the nickel metallocenter (ureD andureEFG) are clustered in R. capsulatus(ureDABC-orf136-ureEFG). No homologues o

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9

Wen, Yi, Jing Feng, David R. Scott, Elizabeth A. Marcus, and George Sachs. "The pH-Responsive Regulon of HP0244 (FlgS), the Cytoplasmic Histidine Kinase of Helicobacter pylori." Journal of Bacteriology 191, no. 2 (2008): 449–60. http://dx.doi.org/10.1128/jb.01219-08.

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ABSTRACT Helicobacter pylori colonizes the acidic gastric environment, in contrast to all other neutralophiles, whose acid resistance and tolerance responses allow only gastric transit. This acid adaptation is dependent on regulation of gene expression in response to pH changes in the periplasm and cytoplasm. The cytoplasmic histidine kinase, HP0244, which until now was thought only to regulate flagellar gene expression via its cognate response regulator, HP0703, was found to generate a response to declining medium pH. Although not required for survival at pH 4.5, HP0244 is required for surviv

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10

Abdulrahman, Alia Talaat, Shna Ibrahim Ismail, Salar Saadi Hussain, Najat Jabbar Ahmed, and Ahmed Nawzad Hassan. "Detection of Helicobacter Pylori’s Virulence Gene (UreA) and its Influence on the Result of Rapid Urease Test (RUT)." Al-Mustansiriyah Journal of Science 33, no. 4 (2022): 42–48. http://dx.doi.org/10.23851/mjs.v33i4.1152.

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UreA is an important virulence factor of Helicobacter pylori that, along with UreB and UreC, produces urease. Urease enzyme helps the bacterium to colonize the human stomach through metabolizing urea in order to neutralize the gastric environment. The current study aimed to detect the prevalence of the H. pylori’s ureA virulence factor gene, and to investigate the influence of this gene on the result of the rapid urease test (RUT). Eighty stomach biopsy samples were isolated from participants who were suspected to be infected with H. pylori in Erbil city. Participants were 36 males and 44 fema

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11

Scott, David R., Elizabeth A. Marcus, David L. Weeks, Adrian Lee, Klaus Melchers, and George Sachs. "Expression of the Helicobacter pylori ureI Gene Is Required for Acidic pH Activation of Cytoplasmic Urease." Infection and Immunity 68, no. 2 (2000): 470–77. http://dx.doi.org/10.1128/iai.68.2.470-477.2000.

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ABSTRACT ureI encodes an integral cytoplasmic membrane protein. It is present in the urease gene cluster of Helicobacter pylori and is essential for infection and acid survival, but its role is unknown. To determine the function of UreI protein, we producedH. pylori ureI deletion mutants and measured the pH dependence of urease activity of intact and lysed bacteria and the effect of urea on the membrane potential. We also determinedureI expression, urease activity, and the effect of urea on membrane potential of several gastric and nongastricHelicobacter species. ureI was found to be present i

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12

Bai, Shengjun, Lingying Xu, Rongkui Ren, et al. "Assessment of Different Humate Ureas on Soil Mineral N Balanced Supply." Agronomy 14, no. 8 (2024): 1856. http://dx.doi.org/10.3390/agronomy14081856.

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Urea supplements, such as humic acids, could enhance fertilizer nitrogen use effectiveness. Melting is superior to mixing for humate urea application; however, the effects of diverse humate ureas from various coal sources on soil N supply remain unclear. This study compared the properties of two humic acids from different coal sources (HA1, weathered coal; HA2, lignite coal), and their impact on soil mineral N supply and the nitrate–ammonium ratio under flooded and 60% water-filled pore space (WFPS) over a 14-day incubation. Humate ureas stimulated soil mineral N accumulation and balanced the

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13

Janovec, Ladislav, Eva Kovacova, Martina Semelakova, et al. "Synthesis of Novel Biologically Active Proflavine Ureas Designed on the Basis of Predicted Entropy Changes." Molecules 26, no. 16 (2021): 4860. http://dx.doi.org/10.3390/molecules26164860.

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A novel series of proflavine ureas, derivatives 11a–11i, were synthesized on the basis of molecular modeling design studies. The structure of the novel ureas was obtained from the pharmacological model, the parameters of which were determined from studies of the structure-activity relationship of previously prepared proflavine ureas bearing n-alkyl chains. The lipophilicity (LogP) and the changes in the standard entropy (ΔS°) of the urea models, the input parameters of the pharmacological model, were determined using quantum mechanics and cheminformatics. The anticancer activity of the synthes

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14

Kim, Jong Kyong, Scott B. Mulrooney, and Robert P. Hausinger. "The UreEF Fusion Protein Provides a Soluble and Functional Form of the UreF Urease Accessory Protein." Journal of Bacteriology 188, no. 24 (2006): 8413–20. http://dx.doi.org/10.1128/jb.01265-06.

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ABSTRACT Four accessory proteins (UreD, UreE, UreF, and UreG) are typically required to form the nickel-containing active site in the urease apoprotein (UreABC). Among the accessory proteins, UreD and UreF have been elusive targets for biochemical and structural characterization because they are not overproduced as soluble proteins. Using the best-studied urease system, in which the Klebsiella aerogenes genes are expressed in Escherichia coli, a translational fusion of ureE and ureF was generated. The UreEF fusion protein was overproduced as a soluble protein with a convenient tag involving th

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15

Saro, Mateo, Andrés, et al. "Replacing Soybean Meal with Urea in Diets for Heavy Fattening Lambs: Effects on Growth, Metabolic Profile and Meat Quality." Animals 9, no. 11 (2019): 974. http://dx.doi.org/10.3390/ani9110974.

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Thirty-six Assaf male lambs (29.4 ± 3.10 kg body weight (BW)) were used to study the feasibility of including urea (at 0, 0.6 or 0.95% of dry matter for Control, Urea1, and Urea2 diets, respectively) in substitution of soybean meal in fattening diets. Animals were individually penned and feed intake was recorded daily. Blood samples were taken at days 35 and 63 of the experimental period to determine the acid-base status and the biochemical profile. At the end of the experiment (nine weeks), lambs were slaughtered, ruminal contents were collected and carcass and meat quality were evaluated. Th

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16

Spencer, J. N., and James W. Hovick. "Solvation of urea and methyl-substituted ureas by water and DMF." Canadian Journal of Chemistry 66, no. 4 (1988): 562–65. http://dx.doi.org/10.1139/v88-096.

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The hydrogen bond enthalpies of urea and methyl-substituted ureas with water and DMF have been determined by the pure-base calorimetric method. Transfer enthalpies between water and DMF have been calculated for dilute solutions of the ureas according to a previously developed model. The first solvation sphere of urea in water consists of five water molecules. Solvation spheres are given for other methyl-substituted ureas in water and DMF.

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17

Varma, Ashok, Shaoxi Wu, Ningru Guo, et al. "Identification of a novel gene, URE2, that functionally complements a urease-negative clinical strain of Cryptococcus neoformans." Microbiology 152, no. 12 (2006): 3723–31. http://dx.doi.org/10.1099/mic.0.2006/000133-0.

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A urease-negative serotype A strain of Cryptococcus neoformans (B-4587) was isolated from the cerebrospinal fluid of an immunocompetent patient with a central nervous system infection. The URE1 gene encoding urease failed to complement the mutant phenotype. Urease-positive clones of B-4587 obtained by complementing with a genomic library of strain H99 harboured an episomal plasmid containing DNA inserts with homology to the sudA gene of Aspergillus nidulans. The gene harboured by these plasmids was named URE2 since it enabled the transformants to grow on media containing urea as the sole nitro

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18

Morávková, Zuzana, Jiří Podešva, Valeriia Shabikova, Sabina Abbrent, and Miroslava Dušková-Smrčková. "Hydrogen Bonding of Trialkyl-Substituted Urea in Organic Environment." Molecules 30, no. 7 (2025): 1410. https://doi.org/10.3390/molecules30071410.

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Urea groups appear in many biomolecules and polymers. They have a significant impact on the properties of the materials because of their inherent strength and for their ability to participate in hydrogen bonds. Typically, in classical urea-based polymer materials, the urea groups occur in their N,N′-disubstituted state. Recently, bis-aspartates have been introduced as a novel type of hindered amine resins providing, upon crosslinking with (poly)isocyanates, the polyurea–polyaspartate thermosets (PU-ASPE) for coatings, sealants, polyelectrolytes, and other applications. These materials contain

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19

Koper, Teresa E., Amal F. El-Sheikh, Jeanette M. Norton, and Martin G. Klotz. "Urease-Encoding Genes in Ammonia-Oxidizing Bacteria." Applied and Environmental Microbiology 70, no. 4 (2004): 2342–48. http://dx.doi.org/10.1128/aem.70.4.2342-2348.2004.

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ABSTRACT Many but not all ammonia-oxidizing bacteria (AOB) produce urease (urea amidohydrolase, EC 3.5.1.5) and are capable of using urea for chemolithotrophic growth. We sequenced the urease operons from two AOB, the β-proteobacterium Nitrosospira sp. strain NpAV and the γ-proteobacterium Nitrosococcus oceani. In both organisms, all seven urease genes were contiguous: the three structural urease genes ureABC were preceded and succeeded by the accessory genes ureD and ureEFG, respectively. Green fluorescent protein reporter gene fusions revealed that the ure genes were under control of a singl

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20

Nim, Yap Shing, and Kam-Bo Wong. "The Maturation Pathway of Nickel Urease." Inorganics 7, no. 7 (2019): 85. http://dx.doi.org/10.3390/inorganics7070085.

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Maturation of urease involves post-translational insertion of nickel ions to form an active site with a carbamylated lysine ligand and is assisted by urease accessory proteins UreD, UreE, UreF and UreG. Here, we review our current understandings on how these urease accessory proteins facilitate the urease maturation. The urease maturation pathway involves the transfer of Ni2+ from UreE → UreG → UreF/UreD → urease. To avoid the release of the toxic metal to the cytoplasm, Ni2+ is transferred from one urease accessory protein to another through specific protein–protein interactions. One central

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21

Hong, Wu, Kouichi Sano, Shinichi Morimatsu, et al. "Medium pH-dependent redistribution of the urease of Helicobacter pylori." Journal of Medical Microbiology 52, no. 3 (2003): 211–16. http://dx.doi.org/10.1099/jmm.0.05072-0.

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Helicobacter pylori is an aetiological agent of gastric disease. Although the role of urease in gastric colonization of H. pylori has been shown, it remains unclear as to where urease is located in this bacterial cell. The purpose of this study was to define the urease-associated apparatus in the H. pylori cytoplasm. H. pylori was incubated at both a neutral and an acidic pH in the presence or absence of urea and examined by double indirect immunoelectron microscopy. The density of gold particles for UreA was greatest in the inner portion of the wild-type H. pylori cytoplasm at neutral pH but

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22

Bussink, D. W., and O. Oenema. "Differences in rainfall and temperature define the use of different types of nitrogen fertilizer on managed grassland in UK, NL [Netherlands] and Eire." Netherlands Journal of Agricultural Science 44, no. 4 (1996): 317–38. http://dx.doi.org/10.18174/njas.v44i4.540.

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There are distinct differences between the Netherlands (NL) and the United Kingdom (UK) in the use of urea and calcium ammonium nitrate (Ca-AmmN) fertilizers on grassland. It has been known for some time that rainfall and temperature affect NH3 volatilization from urea and its agronomic efficiency. This study aimed (i) to examine rainfall and temperature pattern in NL and UK in relation to the observed urea efficiency, and (ii) to provide a simple decision support model for farmers to enable them to choose the most appropriate N fertilizer. A statistical analysis (residual maximum likelihood)

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23

&NA;. "Urea." Reactions Weekly &NA;, no. 1405 (2012): 37. http://dx.doi.org/10.2165/00128415-201214050-00129.

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24

Young, Jay A. "Urea." Journal of Chemical Education 84, no. 9 (2007): 1421. http://dx.doi.org/10.1021/ed084p1421.

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25

Maduell, F., J. Garcia-Valdecasas, H. Garcia, et al. "Urea Reduction Ratio Considering Urea Rebound." Nephron 78, no. 2 (1998): 143–47. http://dx.doi.org/10.1159/000044902.

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26

Bakibaev, A. A. "Evolution of urea from prebiotic molecule to supramolecular architecture (review)." BULLETIN of the L.N. Gumilyov Eurasian National University. Chemistry. Geography. Ecology Series 149, no. 4 (2024): 26–56. https://doi.org/10.32523/2616-6771-2024-149-4-26-56.

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The article shows that urea - as an archetypal prebiotic compound on the one hand, and, reactive oxygen-containing compounds - on the other hand, serve as a basis for the formation of a large repertoire of chemical compounds, which are represented by various acyclic and heterocyclic carbamide-containing substances. Among the urea-containing substances, this paper pays special attention to the use of the prebiotic monomer urea as a starting building block in synthetic organic chemistry, including novel macrocyclic and supramolecular systems. Although most of the urea chemistry experiments perfo

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27

Zhao, Hui, Richard B. Thompson, Virginia Lockatell, David E. Johnson, and Harry L. T. Mobley. "Use of Green Fluorescent Protein To Assess Urease Gene Expression by Uropathogenic Proteus mirabilis during Experimental Ascending Urinary Tract Infection." Infection and Immunity 66, no. 1 (1998): 330–35. http://dx.doi.org/10.1128/iai.66.1.330-335.1998.

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ABSTRACT Proteus mirabilis, a cause of complicated urinary tract infection, expresses urease when exposed to urea. While it is recognized that the positive transcriptional activator UreR induces gene expression, the levels of expression of the enzyme during experimental infection are not known. To investigate in vivo expression of P. mirabilis urease, the gene encoding green fluorescent protein (GFP) was used to construct reporter fusions. Translational fusions of urease accessory gene ureD, which is preceded by a urea-inducible promoter, were made withgfp (modified to express S65T/V68L/S72A [

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28

Magerramov, A. M., R. T. Abdinbekova, M. M. Kurbanova, A. V. Zamanova, and M. A. Allakhverdiev. "Synthesis of substituted ureas from urea and halohydrins." Russian Journal of Applied Chemistry 77, no. 10 (2004): 1667–69. http://dx.doi.org/10.1007/s11167-005-0093-6.

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29

Gruninger, Stephen E., and Manuel Goldman. "Evidence for urea cycle activity in Sporosarcina ureae." Archives of Microbiology 150, no. 4 (1988): 394–99. http://dx.doi.org/10.1007/bf00408313.

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Akgun, Ugur. "Mechanism of Urea Conduction through H. Pylori UreI." Biophysical Journal 110, no. 3 (2016): 545a. http://dx.doi.org/10.1016/j.bpj.2015.11.2917.

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31

Kathiravan, Subban, Prakriti Dhillon, Tianshu Zhang, and Ian A. Nicholls. "Synthesis of Unsymmetrical Urea Derivatives via PhI(OAc)2 and Application in Late-Stage Drug Functionalization." Molecules 29, no. 23 (2024): 5669. https://doi.org/10.3390/molecules29235669.

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Unsymmetrical urea derivatives are essential structural motifs in a wide array of biologically significant compounds. Despite the well-established methods for synthesizing symmetrical ureas, efficient strategies for the synthesis of unsymmetrical urea derivatives remain limited. In this study, we present a novel approach for the synthesis of unsymmetrical urea derivatives through the coupling of amides and amines. Utilizing hypervalent iodine reagent PhI(OAc)2 as a coupling mediator, this method circumvents the need for metal catalysts, high temperatures, and inert atmosphere. The reaction pro

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32

Bakibaev, А. А., М. Zh Sadvakassova, V. S. Malkov, R. Sh Еrkasov, A. A. Sorvanov, and O. A. Kotelnikov. "Study of the biologically active acyclic ureas by nuclear magnetic resonance." Bulletin of the Karaganda University. "Chemistry" series 100, no. 4 (2020): 60–74. http://dx.doi.org/10.31489/2020ch4/60-74.

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A wide variety of acyclic ureas comprising alkyl, arylalkyl, acyl, and aryl functional groups are investigated by nuclear magnetic resonance spectroscopy. In general, spectral characteristics of more than 130 substances based on acyclic ureas dissolved in deuterated dimethyl sulfoxide at room temperature are studied. The re-sults obtained based on the studies of 1H and 13C NMR spectra of urea and its N-alkyl-, N-arylalkyl-, N-aryl- and 1,3-diaryl derivatives are presented, and the effect of these functional groups on the chemical shifts in carbonyl and amide moieties in acyclic urea derivative

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33

Zorc, Branka, Zrinka Rajić, and Ivana Perković. "Antiproliferative evaluation of various aminoquinoline derivatives." Acta Pharmaceutica 69, no. 4 (2019): 661–72. http://dx.doi.org/10.2478/acph-2019-0048.

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Abstract Four classes of aminoquinoline derivatives were prepared: primaquine ureas 1a–f, primaquine bis-ureas 2a–f, chloroquine fumardiamides 3a–f and mefloquine fumardiamides 4a–f. Their antiproliferative activities against breast adeno-carcinoma (MCF-7), lung carcinoma (H460) and colon carcinoma (HCT 116 and SW620) cell lines were evaluated in vitro, using MTT cell proliferation assay. The results revealed a low activity of primaquine urea and bis-urea derivatives and high activity of all fumardiamides, with IC50 values in low micromolar range against all tested cancer cell lines.

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34

Yerokun, O. A. "Response of maize to ammonium nitrate, urea and cogranulated urea-urea phosphate." South African Journal of Plant and Soil 14, no. 2 (1997): 63–66. http://dx.doi.org/10.1080/02571862.1997.10635083.

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Chakraborty, Ranabir, T. J. Purakayastha, B. Ramakrishnan, Babanpreet Kour, Arpan Bhowmik, and Abinash Das. "Long Term Effect of Residue Management, Nitrification and Urease Inhibitor on Non-target Soil Bacterial Community in Rice–Wheat and Maize–Wheat Cropping Systems." International Journal of Bio-resource and Stress Management 15, July, 7 (2024): 01–13. http://dx.doi.org/10.23910/1.2024.5393.

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An investigation was carried out from November, 2020 to April, 2021 at the Indian Agricultural Research Institute, New Delhi, employing a split-split plot layout with two cropping systems (rice-wheat and maize-wheat), four long-term crop residue management strategies including burning (CRB), removal (CRR), incorporation (CRI), and biochar (BC), and two nitrogen management: neem-coated urea (NCU) and Urea+dual (urease+nitrification) inhibitor (UUINI). Soil DNA was extracted and quantified for 16S bacteria, 16S archaea, nifH, ureC and anammox abundances using quantitative PCR. Additionally, Soil

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Carter, Eric L., and Robert P. Hausinger. "Characterization of the Klebsiella aerogenes Urease Accessory Protein UreD in Fusion with the Maltose Binding Protein." Journal of Bacteriology 192, no. 9 (2010): 2294–304. http://dx.doi.org/10.1128/jb.01426-09.

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ABSTRACT Assembly of the Klebsiella aerogenes urease metallocenter requires four accessory proteins, UreD, UreE, UreF, and UreG, to effectively deliver and incorporate two Ni2+ ions into the nascent active site of the urease apoprotein (UreABC). Each accessory protein has been purified and characterized with the exception of UreD due to its insolubility when it is overproduced in recombinant cells. In this study, a translational fusion was made between the maltose binding protein (MBP) and UreD, with the resulting MBP-UreD found to be soluble in Escherichia coli cell extracts and able to compl

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Masaaki Minami, Shin-nosuke Hashikawa, Takafumi Ando, Hiroshi Kobayashi, Hidemi Goto, and Michio Ohta. "Involvement of CO2 generated by urease in multiplication of Helicobacter pylori." GSC Advanced Research and Reviews 7, no. 3 (2021): 045–53. http://dx.doi.org/10.30574/gscarr.2021.7.3.0123.

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Helicobacter pylori (H. pylori) urease generates both ammonia (NH3) and carbon dioxide (CO2) from urea. NH3 helps H. pylori to survive in the stomach in part by neutralizing gastric acid. However, the relationship between CO2 and H. pylori is not completed cleared. We examined the effect of CO2 generated by urease on multiplication of H. pylori by using isogenic ureB mutant and ureB complemented strain from H. pylori strain JP26. Wild-type strain survived in the medium supplement with 1mM urea in room air, however, the urease negative strain did not. To discern whether CO2 was incorporated int

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Sein, K. T., and G. Arumainayagam. "Correlation between serum urea and salivary urea." Clinical Chemistry 33, no. 12 (1987): 2303–4. http://dx.doi.org/10.1093/clinchem/33.12.2303.

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Kågedal, Bertil. "Why “Urea Nitrogen” When Urea is Measured?" Clinical Chemistry 44, no. 4 (1998): 894–95. http://dx.doi.org/10.1093/clinchem/44.4.894.

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RODRIGUES, M., J. PIDLICH, C. MÜLLER, and H. SINZINGER. "13C-urea versus 14C-urea breath test." Nuclear Medicine Communications 19, no. 11 (1998): 1021–22. http://dx.doi.org/10.1097/00006231-199811000-00001.

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HART, G. C., and M. P. AVISON. "13C-urea versus 14C-urea breath test." Nuclear Medicine Communications 20, no. 5 (1999): 495. http://dx.doi.org/10.1097/00006231-199905000-00141.

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RODRIGUES, M., J. PIDLICH, C. MULLER, and H. SINZINGER. "13C-urea versus 14C-urea breath tests." Nuclear Medicine Communications 20, no. 5 (1999): 495–96. http://dx.doi.org/10.1097/00006231-199905000-00142.

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MILLAR, A. M., and J. HANNAN. "13C-urea versus 14C-urea breath test." Nuclear Medicine Communications 20, no. 7 (1999): 686. http://dx.doi.org/10.1097/00006231-199907000-00043.

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Kaatze, Udo. "Hydration of urea and alkylated urea derivatives." Journal of Chemical Physics 148, no. 1 (2018): 014504. http://dx.doi.org/10.1063/1.5003569.

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Simioni, F., and M. Modesti. "Glycolysis of Flexible Polyurethane Foams." Cellular Polymers 12, no. 5 (1993): 337–48. http://dx.doi.org/10.1177/026248939301200501.

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Flexible water blown polyurethanes are polymers with repeating urethane and urea groups. When they undergo heating in the presence of glycols the reaction of these groups leads to soluble products. The transesterification reaction of the urethane groups, that leads to the formation of new carbamate is faster than that of the urea groups. Carbamates in turn undergo aminolysis due to the amines formed in the glycolysis of the urea groups. The use of ethylene glycol (EG) allows the process to be carried out with high polymer/glycol ratio (up to 4:1). A polyphase product is obtained with a top liq

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Rabindra, B. "Improved Management of Urea in Rice." International Rice Research Newsletter 11, no. 5 (1986): 42. https://doi.org/10.5281/zenodo.7002395.

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This article 'Improved Management of Urea in Rice' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

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Rabindra, B., B. S. Naidu, T. G. Devi, and S. N. Gowda. "Large Granule Urea Efficiency in Rice." International Rice Research Newsletter 14, no. 2 (1989): 26–27. https://doi.org/10.5281/zenodo.7146610.

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This article 'Large Granule Urea Efficiency in Rice' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

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Sachs, George, David L. Weeks, Yi Wen, Elizabeth A. Marcus, David R. Scott, and Klaus Melchers. "Acid Acclimation byHelicobacter pylori." Physiology 20, no. 6 (2005): 429–38. http://dx.doi.org/10.1152/physiol.00032.2005.

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Helicobacter pylori is a Gram-negative neutralophile associated with peptic ulcers and gastric cancer. It has a unique ability to colonize the human stomach by acid acclimation. It uses the pH-gated urea channel, UreI, to enhance urea access to intrabacterial urease and a membrane-anchored periplasmic carbonic anhydrase to regulate periplasmic pH to ~6.1 in acidic media, whereas other neutralophiles cannot regulate periplasmic pH and thus only transit the stomach.

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Rekhi, R. S., M. S. Bajwa, and J. L. Starr. "Efficiency of Prilled Urea (PU) and Urea Supergranules (USG) in Rapidly Percolating Soil." International Rice Research Newsletter 14, no. 2 (1989): 28. https://doi.org/10.5281/zenodo.7146524.

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This article 'Efficiency of Prilled Urea (PU) and Urea Supergranules (USG) in Rapidly Percolating Soil' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world

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WOOD, CHRIS M., R. S. MUNGER, and D. P. TOEWS. "Ammonia, Urea and H+ Distribution and the Evolution of Ureotelism in Amphibians." Journal of Experimental Biology 144, no. 1 (1989): 215–33. http://dx.doi.org/10.1242/jeb.144.1.215.

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In theory, the distribution of ammonia across cell membranes (Tammi/Tamme) between intracellular and extracellular fluids (ICF and ECF) may be determined by the transmembrane pH gradient (as in mammals), the transmembrane potential (as in teleost fish), or both, depending on the relative permeability of the membranes to NH3 and NH4+ (pNH3/pNH4+). The resting distributions of H+ (via [14C]DMO), ammonia and urea between plasma and skeletal muscle, and the relative excretion rates of ammonia-N and urea-N, were measured in five amphibian species (Bufo marinus, Ambystoma tigrinum, Rana catesbeiana,

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