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1. Lanthanum-incorporated β-Ni(OH)₂ nanoarrays for robust urea electro-oxidation

Author:
Hao, Pin; Xin, Ying; Wang, Qian; Li, Liyi; Zhao, Zhenhuan; Wen, Houguang; Xie, Junfeng; Cui, Guanwei; Tang, Bo
Source:
Chemical communications 2021 v.57 no.16 pp. 2029-2032
ISSN:
1364-548X
Subject:
urea,   etc   ; catalytic activity; nanosheets;     Show all 3 Subjects
Abstract:
... Lanthanum-incorporated β-Ni(OH)₂ nanosheets display superior catalytic behavior and stability for urea electro-oxidation, which originates from the optimized electronic structure, the downshift of the d-band center and the increased number of exposed active sites. ...
DOI:
10.1039/d0cc07969c

2. Effects of different types of slow- and controlled-release fertilizers on rice yield

Author:
WU, Qiong; WANG, Yu-hui; DING, Yan-feng; TAO, Wei-ke; GAO, Shen; LI, Quan-xin; LI, Wei-wei; LIU, Zheng-hui; LI, Gang-hua
Source:
Journal of integrative agriculture 2021 v.20 no.6 pp. 1503-1514
ISSN:
2095-3119
Subject:
polymer-coated urea; sulfur-coated urea; urea,   etc   ; agriculture; dry matter accumulation; nitrogen; panicles; rice; seedlings; spikelets; urea formaldehyde; urease inhibitors;     Show all 12 Subjects
Abstract:
... This experiment explored the effects of single application of seven types of slow- and controlled-release fertilizers on rice yield and various population characteristics. Based on a study of the nitrogen (N) release characteristics of these fertilizers, pot experiments were conducted in 2018 and 2019 with split fertilization (CK, urea applied split equally at basal and panicle initiation stages, ...
DOI:
10.1016/S2095-3119(20)63406-2

3. Role of in situ added cellulose nanocrystals as rheological modulator of novel waterborne polyurethane urea for 3D-printing technology

Author:
Vadillo, Julen; Larraza, Izaskun; Calvo-Correas, Tamara; Gabilondo, Nagore; Derail, Christophe; Eceiza, Arantxa
Source:
Cellulose 2021 v.28 no.8 pp. 4729-4744
ISSN:
0969-0239
Subject:
urea,   etc   ; cellulose; nanocrystals; polyurethanes; viability;     Show all 5 Subjects
Abstract:
... Cellulose nanocrystals (CNC) have been studied as rheological modulator in order to improve the printing performance of a novel polycaprolactone-polyethylene glycol (PCL-PEG) waterborne polyurethane urea (WBPUU) based ink for direct ink writing 3D-printing technology. The cellulose nanocrystals are chemically bonded to the WBPU, since they were added during the synthesis of a WBPUU, in order to tu ...
DOI:
10.1007/s10570-021-03826-6

4. An L-tert-leucine derived urea catalyzed asymmetric synthesis of acylclic N, N′-ketals derived from aryl amines and isatin-derived ketimines

Author:
Liu, Shuo; Wang, Jingdong; Wei, Zhonglin; Cao, Jungang; Liang, Dapeng; Lin, Yingjie; Duan, Haifeng
Source:
Tetrahedron 2021 pp. 132206
ISSN:
0040-4020
Subject:
urea,   etc   ; catalysts; ketimines; stereoselective synthesis;     Show all 4 Subjects
Abstract:
... An asymmetric synthesis of N,N′-ketal compounds derived from isatin-derived ketimines and aryl amines has been developed using an inexpensive and readily available L-tert-leucine derived urea catalyst. Using this asymmetric catalytic synthetic method, a series of 3-substituted 3-amino-2-oxoindole derivatives containing an N,N′-ketal motif were obtained in high yields with high enantioselectivities ...
DOI:
10.1016/j.tet.2021.132206

5. Stabilization of the hindered urea bond through de-tert-butylation

Author:
Yang, Yingfeng; Ying, Hanze; Jia, Yunchao; Chen, Yingying; Cheng, Jianjun
Source:
Chemical communications 2021 v.57 no.31 pp. 3812-3815
ISSN:
1364-548X
Subject:
urea,   etc   ; chemical communication; mechanical properties;     Show all 3 Subjects
Abstract:
... We report the discovery of an acid-assisted de-tert-butylation reaction that can instantly “turn off” the dynamicity of hindered urea bonds (HUBs) and thus broaden their applications. The reaction is demonstrated to be widely applicable to different hindered urea substrates, leading to improved chemical stabilities and mechanical properties of HUB-containing materials. ...
DOI:
10.1039/d1cc00715g

6. Optimizing the use of open chambers to measure ammonia volatilization in field plots amended with urea

Author:
MARTINS, Márcio R.; SARKIS, Leonardo F.; SANT'ANNA, Selenobaldo A.C.; SANTOS, Camila A.; ARAUJO, Karla E.; SANTOS, Ricardo C.; ARAÚJO, Ednaldo S.; ALVES, Bruno J.R.; JANTALIA, Claudia P.; BODDEY, Robert M.; ZAMAN, Mohammad; URQUIAGA, Segundo
Source:
Pedosphere 2021 v.31 no.2 pp. 243-254
ISSN:
1002-0160
Subject:
urea,   etc   ; ammonia; nitrogen; uncertainty; volatilization;     Show all 5 Subjects
Abstract:
... Measuring ammonia (NH₃) volatilization from urea-fertilized soils is crucial for evaluation of practices that reduce gaseous nitrogen (N) losses in agriculture. The small area of chambers used for NH₃ volatilization measurements compared with the size of field plots may cause significant errors if inadequate sampling strategies are adopted. Our aims were: i) to investigate the effect of using mult ...
DOI:
10.1016/S1002-0160(20)60078-9

7. New insights into ethyl carbamate occurrence in fortified wines

Author:
Leça, João M.; Pereira, Vanda; Miranda, Andreia; Vilchez, José Luis; Marques, José C.
Source:
Lebensmittel-Wissenschaft + [i.e. und] Technologie 2021 v.150 pp. 111566
ISSN:
0023-6438
Subject:
urea,   etc   ; arginine; citrulline; ethyl carbamate; fructose; glucose;     Show all 6 Subjects
Abstract:
... The occurrence of ethyl carbamate (EC) in fortified wines was studied testing different model wines under accelerated ageing (45 °C for 4 months and 70 °C for 1 month), to investigate the possibility of arginine (Arg) being a direct precursor of EC in fortified wines, comparing it with known major precursors, urea and citrulline (Cit). Wine main sugars were appraised as possible catalysts, as prev ...
DOI:
10.1016/j.lwt.2021.111566

8. Ultrafast Fabrication of Self-Healing and Injectable Carboxymethyl Chitosan Hydrogel Dressing for Wound Healing

Author:
Cao, Jinfeng; Wu, Ping; Cheng, Qianqian; He, Chen; Chen, Yun; Zhou, Jinping
Source:
ACS applied materials & interfaces 2021 v.13 no.20 pp. 24095-24105
ISSN:
1944-8252
Subject:
urea,   etc   ; chitosan; gelation; hydrogels; separation; tissue repair;     Show all 6 Subjects
Abstract:
... Herein, a new type of injectable carboxymethyl chitosan (CMCh) hydrogel wound dressing with self-healing properties is constructed. First, CMCh samples are homogeneously synthesized in alkali/urea aqueous solutions. Subsequently, trivalent metal ions of Fe³⁺ and Al³⁺ are introduced to form coordination bonds with CMCh, leading to an ultrafast gelation process. A series of hydrogels can be obtained ...
DOI:
10.1021/acsami.1c02089

9. Effects of Ionic Liquids on Aqueous Urea Solutions: Insights into the Ionic Liquid-Assisted Protein Renaturation

Author:
Rahman, Mohammad Homaidur; Senapati, Sanjib
Source:
TheJournal of physical chemistry 2021 v.125 no.18 pp. 4808-4818
ISSN:
1520-5207
Subject:
urea,   etc   ; molecular dynamics; nitrates; peptides; protein denaturation;     Show all 5 Subjects
Abstract:
... Ionic liquids (ILs) are designer solvents that find wide applications in various areas. Recently, ILs have been shown to induce the refolding of certain proteins that were previously denatured under the treatment of urea. A molecular-level understanding of the counteracting mechanism of ILs on urea-induced protein denaturation remains elusive. In this study, we employ atomistic molecular dynamics ...
DOI:
10.1021/acs.jpcb.1c00586

10. Spin State Tuning of the Octahedral Sites in Ni–Co-Based Spinel toward Highly Efficient Urea Oxidation Reaction

Author:
Li, Yu; Jiang, Hui; Cui, Zhenduo; Zhu, Shengli; Li, Zhaoyang; Wu, Shuilin; Ma, Lili; Han, Xiaopeng; Liang, Yanqin
Source:
Journal of physical chemistry 2021 v.125 no.17 pp. 9190-9199
ISSN:
1932-7455
Subject:
urea,   etc   ; electrochemistry; guidelines; nickel; oxidation; oxygen production;     Show all 6 Subjects
Abstract:
... Nickel–cobalt spinel oxide is an efficient electrocatalyst for urea oxidation reaction (UOR) due to its low cost and high activity. The eg orbital occupancy of transition metal ions in spinel oxides can determine the oxygen evolution reaction activity. However, the eg filling, the catalyzing active sites, and the related UOR mechanisms in spinel catalysts are still unknown. Here, from the perspect ...
DOI:
10.1021/acs.jpcc.1c02116

11. A Doubly Kinetically-Gated Information Ratchet Autonomously Driven by Carbodiimide Hydration

Author:
Borsley, Stefan; Leigh, David A.; Roberts, Benjamin M. W.
Source:
Journal of the American Chemical Society 2021 v.143 no.11 pp. 4414-4420
ISSN:
1520-5126
Subject:
urea,   etc   ; catalysts; energy; hydrogen; hydrolysis; isomers; wastes;     Show all 7 Subjects
Abstract:
... We report a rotaxane-based information ratchet in which the macrocycle distribution is pumped away from equilibrium using a carbodiimide fuel. A carboxylate group on the axle, nonequidistant between two macrocycle binding sites, efficiently catalyzes the hydration of a carbodiimide fuel to the corresponding urea waste, with >80% of the fuel molecules reacting through the machine-catalyzed pathway. ...
DOI:
10.1021/jacs.1c01172

12. Linking soil profile N2O concentration with surface flux in a cotton field under drip fertigation

Author:
Li, Yanyan; Gao, Xiaopeng; Tenuta, Mario; Gui, Dongwei; Li, Xiangyi; Zeng, Fanjiang
Source:
Environmental pollution 2021 v.285 pp. 117458
ISSN:
0269-7491
Subject:
polymer-coated urea; urea,   etc   ; cotton; fertigation; nitrogen; pollution; soil profiles; soil water; China;     Show all 9 Subjects
Abstract:
... It remains unclear how the source and rate of nitrogen (N) fertilizers affect N₂O concentration and effluxes along the soil profile under the drip-fertigated agricultural system. A plot-based field study was performed in 2017 and 2018 in a cotton field in arid northwestern China, with an objective to elucidate the impact of the applications of conventional urea (Urea), polymer-coated urea (ESN) an ...
DOI:
10.1016/j.envpol.2021.117458

13. Electrochemical recovery of H2 and nutrients (N, P) from synthetic source separate urine water

Author:
Govindan, Kadarkarai; Im, Sung-Ju; Muthuraj, Velluchamy; Jang, Am
Source:
Chemosphere 2021 v.269 pp. 129361
ISSN:
0045-6535
Subject:
urea; urea nitrogen,   etc   ; anodes; cathodes; electrochemistry; electrolysis; foams; hydrogen; pH; total Kjeldahl nitrogen; urine;     Show all 11 Subjects
Abstract:
... This study examined an electrochemical method of H₂ production and nutrient recovery from synthetic source separated urine (SSU). The efficacy of H₂ production was examined through hydrogen recovery experiments (HRE) using Ni foam electrodes. Similarly, nutrient (N and P) recovery was also examined in post-nutrient recovery experiments (NRE) with sacrificial Mg electrodes. To achieve higher nutrie ...
DOI:
10.1016/j.chemosphere.2020.129361

14. Nitrogen Recovery from Enhanced Efficiency Fertilizers and Urea in Intensively Managed Black Walnut (Juglans nigra) Plantations

Author:
Sloan, Joshua L.; Salifu, Francis K.; Jacobs, Douglass F.
Source:
Forests 2021 v.12 no.3
ISSN:
1999-4907
Subject:
polymer-coated urea; urea,   etc   ; Juglans nigra; boron; ecosystems; forests; nitrogen; phosphates; urease inhibitors; water solubility;     Show all 10 Subjects
Abstract:
... Intensively managed forest plantations often require fertilization to maintain site fertility and to improve growth and yield over successive rotations. We applied urea-based “enhanced-efficiency fertilizers” (EEF) containing 0.5 atom% ¹⁵N at a rate of 224 kg N ha⁻¹ to soils under mid-rotation black walnut (Juglans nigra L.) plantations to track the fate of applied ¹⁵N within aboveground ecosystem ...
DOI:
10.3390/f12030352

15. Fall-applied cattle manure did not provide nitrogen fertilizer value to spring cereal crops

Author:
Ejack, Leanne; Hung, Chih-Yu; Whalen, Joann K.
Source:
Canadian journal of soil science 2021 v.101 no.2 pp. 344-347
ISSN:
1918-1841
Subject:
urea; urea fertilizers,   etc   ; cattle manure; liquids; nitrogen; sandy loam soils; spring; tillering; total nitrogen; Quebec;     Show all 10 Subjects
Abstract:
... Fall-applied manure may have nitrogen (N) fertilizer value for spring-seeded crops. We applied liquid or solid cattle manure to plots on a sandy-loam soil in southern Quebec in fall. The following spring, half of each plot received urea fertilizer before planting the spring cereal crop. Total N content of the spring cereal at tillering, flowering, and maturity was lower in subplots without urea, a ...
DOI:
10.1139/cjss-2020-0126

16. Changes of δ15N values during the volatilization process after applying urea on soil

Author:
Ti, Chaopu; Ma, Shutan; Peng, Lingyun; Tao, Limin; Wang, Xi; Dong, Wenxu; Wang, Liangjie; Yan, Xiaoyuan
Source:
Environmental pollution 2021 v.270 pp. 116204
ISSN:
0269-7491
Subject:
urea; urea nitrogen,   etc   ; air pollution; ammonia; isotope fractionation; nitrogen cycle; soil; volatilization;     Show all 8 Subjects
Abstract:
... Ammonia (NH₃) volatilized from soils plays an important role in N cycle and air pollution, thus it is important to trace the emission source and predict source contributions to development strategies mitigating the environmental harmful of soil NH₃ volatilization. The measurements of ¹⁵N natural abundance (δ¹⁵N) could be used as a complementary tool for apportioning emissions sources to resolve th ...
DOI:
10.1016/j.envpol.2020.116204

17. A synthetic peptide as an allosteric inhibitor of human arginase I and II

Author:
Gao, Kai; Lunev, Sergey; van den Berg, Mariska P. M.; Al-Dahmani, Zayana M.; Evans, Stephen; Mertens, Dyon A. L. J.; Meurs, Herman; Gosens, Reinoud; Groves, Matthew R.
Source:
Molecular biology reports 2021 v.48 no.2 pp. 1959-1966
ISSN:
0301-4851
Subject:
urea; urea cycle,   etc   ; ammonia; arginase; arginine; blood; humans; hydrolysis; kidneys; kinetics; metabolism; molecular biology; synthetic peptides;     Show all 13 Subjects
Abstract:
... Arginine metabolism mediated by arginases plays a critical role in cell and tissue function. The arginine hydrolysis is deeply involved in the urea cycle, which helps the kidney excrete ammonia from blood. Upregulation of arginases affects microenvironment stability due to the presence of excess urea in blood. To regulate the arginase activities properly, a synthetic peptide based on the structure ...
DOI:
10.1007/s11033-021-06176-5

18. Milk urea nitrogen variation explained by differences in urea transport into the gastrointestinal tract in lactating dairy cows

Author:
Souza, V.C.; Aguilar, M.; Van Amburgh, M.; Nayananjalie, W.A.D.; Hanigan, M.D.
Source:
Journal of dairy science 2021 v.104 no.6 pp. 6715-6726
ISSN:
0022-0302
Subject:
urea; urea cycle; urea nitrogen,   etc   ; anabolism; dairy science; diet; digestive tract; excretion; feces; gastrointestinal system; herds; isotopic enrichment; kidneys; milk; nitrogen; nitrogen balance; urine;     Show all 17 Subjects
Abstract:
... Milk urea nitrogen (MUN) and blood urea nitrogen are correlated with nitrogen balance and nitrogen excretion; however, there is also a genetic component to MUN concentrations that could be associated with differences in urea transport. It was hypothesized that a portion of the variation in MUN concentrations among cows is caused by variation in gastrointestinal and kidney urea clearance rates. Eig ...
DOI:
10.3168/jds.2020-19787

19. Evaluation of selected medicinal plant materials and dicyandiamide on nitrification of urea‐derived ammonium under laboratory conditions

Author:
Tahir, Majid Mahmood; Begum, Shahida; Maqbool, Mehdi; Khaliq, Abdul; Zahid, Noosheen; Mehmood, Khalid; Shehzad, Muhammad
Source:
Journal of plant nutrition and soil science 2021 v.184 no.1 pp. 132-141
ISSN:
1436-8730
Subject:
urea; urea fertilizers; urea nitrogen,   etc   ; Allium; Artemisia; Azadirachta indica; Fumaria; Viola odorata; ammonium; ammonium nitrogen; dicyandiamide; medicinal plants; nitrification; nitrogen; oxidation; plant nutrition; soil;     Show all 17 Subjects
Abstract:
... Background: Poor utilization of urea fertilizer and N losses from agriculture lands demands alternate fertilization practices to reduce N losses and improve utilization, i.e., application of nitrification inhibitors. Aims: This study was aimed to evaluate and compare the influence of dicyandiamide (DCD) and selected medicinal plant materials and on N transformations, nitrification inhibition and r ...
DOI:
10.1002/jpln.201900501

20. Effective synthetic strategy towards highly selective macrocyclic anion receptors based on static combinatorial chemistry

Author:
Niedbała, Patryk; Jurczak, Janusz
Source:
Tetrahedron 2020 v.76 no.52 pp. 131693
ISSN:
0040-4020
Subject:
urea,   etc   ; methodology; receptors; synthesis;     Show all 4 Subjects
Abstract:
... We present the synthesis, using combinatorial chemistry methodology, of a series of 11 selective anion receptors with special affinity for carboxylates. These compounds contain a urea function and their macrocyclic platform has the structure of previously reported “Unclosed Cryptand”. The use, at the stage of postfunctionalisation of the lariat arm, of properly selected templates allows for non-st ...
DOI:
10.1016/j.tet.2020.131693