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Relevant bibliographies by topics / Urea hosts

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Academic literature on the topic 'Urea hosts'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

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Journal articles on the topic "Urea hosts"

1

Shinde, Sudhirkumar, Anil Incel, Mona Mansour, Gustaf D. Olsson, Ian A. Nicholls, Cem Esen, Javier Urraca, and Börje Sellergren. "Urea-Based Imprinted Polymer Hosts with Switchable Anion Preference." Journal of the American Chemical Society 142, no. 26 (May 19, 2020): 11404–16. http://dx.doi.org/10.1021/jacs.0c00707.

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Connor, Alan L., Ting Hu, Cadnel S. F. Detchou, Rui Liu, Surya V. S. R. K. Pulavarti, Thomas Szyperski, Zhonglin Lu, and Bing Gong. "Aromatic oligureas as hosts for anions and cations." Chemical Communications 52, no. 64 (2016): 9905–8. http://dx.doi.org/10.1039/c6cc03681c.

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Intramolecularly H-bonded urea moieties of aromatic oligoureas bind anions in modest affinities. Extending backbone length results in a cation-binding cavity, allowing the resultant oligomer to bind both anions and cations.

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3

Jia, Chuandong, Qi-Qiang Wang, Rowshan Ara Begum, Victor W. Day, and Kristin Bowman-James. "Chelate effects in sulfate binding by amide/urea-based ligands." Organic & Biomolecular Chemistry 13, no. 25 (2015): 6953–57. http://dx.doi.org/10.1039/c5ob00618j.

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Chelate and mini-chelate effects on sulfate binding was explored for six amide-, amide/amine-, urea-, and urea/amine-based ligands in water-mixed DMSO-d₆. The urea hosts were highly selective for SO₄²⁻, and displayed enhanced binding and greater tolerance for increasing water content as the number of chelate groups increased.

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Yutronic, Nicolás, Juan Merchán, Guillermo González, and María Teresa Garland. "Protonated bis(quinuclidine) included in layered bis(urea)–bromide and -iodide hosts: new ternary urea inclusion compounds." J. Chem. Soc., Perkin Trans. 2, no. 11 (2002): 1956–59. http://dx.doi.org/10.1039/b201053b.

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5

Dhall, Manish, and A. K. Madan. "Comparison of cyclodextrins and urea as hosts for inclusion of drugs." Journal of Inclusion Phenomena and Macrocyclic Chemistry 89, no. 3-4 (September 2, 2017): 207–27. http://dx.doi.org/10.1007/s10847-017-0748-y.

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6

Tanaka, Koichi, Naoki Daikawa, and Shigeru Ohba. "Novel Bisurea Host Compounds." Journal of Chemical Research 2002, no. 11 (November 2002): 579–81. http://dx.doi.org/10.3184/030823402103170853.

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New host molecules, 4,4′-bis(dimethylamino-urea)diphenylmethane (1) and its derivatives (2 and 3), are reported. These hosts are shown to give inclusion complex crystals with a wide variety of organic guest molecules with high selectivity. The crystal structure of 1:2 inclusion complex of 1 with THF has been determined from X-ray crystal structure analysis. The cyclic N–H...O intermolecular hydrogen bonds between host molecules were found to form columns for accommodation of the guest molecules.

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7

Bell, Thomas W., and Jia Liu. "Hexagonal lattice hosts for urea. A new series of designed heterocyclic receptors." Journal of the American Chemical Society 110, no. 11 (May 1988): 3673–74. http://dx.doi.org/10.1021/ja00219a060.

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8

Jurczak, Janusz, Michał J. Chmielewski, Paweł Dydio, Dawid Lichosyt, Filip Ulatowski, and Tomasz Zieliński. "Benzopyrrole derivatives as effective anion receptors in highly competitive solvents." Pure and Applied Chemistry 83, no. 8 (June 24, 2011): 1543–54. http://dx.doi.org/10.1351/pac-con-10-11-11.

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Neutral anion receptors working in highly demanding solvents are new materials being sought. Benzopyrroles are more acidic than amides and pyrrole itself, and are promising building blocks in the design of host compounds. A whole series of receptors based upon benzopyrroles were synthesized and evaluated. They include carbazole, dipyrrolonaph-thalene, and 7-aminoindole-based hosts. Most of them demonstrate moderate binding affinities in dimethyl sulfoxide (DMSO) and have good selectivity toward tetrahedral oxyanions. Recently, a group of receptors utilizing 7-aminoindole and urea moieties proved to work in a very competitive solvent—methanol.

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9

Collins, D., D. C. Winter, A. M. Hogan, L. Schirmer, A. W. Baird, and G. S. Stewart. "Differential protein abundance and function of UT-B urea transporters in human colon." American Journal of Physiology-Gastrointestinal and Liver Physiology 298, no. 3 (March 2010): G345—G351. http://dx.doi.org/10.1152/ajpgi.00405.2009.

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Facilitative UT-B urea transporters enable the passage of urea across cell membranes. Gastrointestinal urea transporters are thought to play a significant role in the urea nitrogen salvaging process that occurs between mammalian hosts and their gut bacteria. This study investigated the expression of UT-B urea transporters in different segments of human colon. Immunoblot analysis showed that human colon expressed a 35-kDa glycosylated UT-B protein in the colonic mucosa. The 35-kDa UT-B transporter was predominantly located in plasma membrane-enriched samples ( P < 0.001; n = 6), and its expression was greater in the ascending colon compared with the descending colon ( P < 0.01; n = 3). At the cellular level, UT-B transporters were located throughout colonocytes situated in the upper portion of the colonic crypts. Bidirectional trans-epithelial urea transport was significantly greater in the ascending colon than the descending colon ( P < 0.05; n = 6). In addition, the facilitative urea transporter inhibitor 1,3,dimethylurea significantly reduced urea transport in the ascending colon ( P < 0.05; n = 6) but had no effect in the descending colon (NS; n = 6). These results illustrate differential protein abundance of functional UT-B protein in different sections of the human colon, strongly correlating to regions that contain the largest populations of intestinal bacteria. This study suggests an important role for UT-B urea transporters in maintaining the symbiotic relationship between humans and their gut bacteria.

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Hollingsworth, Mark D., Kenneth D. M. Harris, William Jones, and John M. Thomas. "ESR and X-ray diffraction studies of diacyl peroxides in urea and aluminosilicate hosts." Journal of Inclusion Phenomena 5, no. 2 (April 1987): 273–77. http://dx.doi.org/10.1007/bf00655664.

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Dissertations / Theses on the topic "Urea hosts"

1

Pratt, Michelle. "Metal-directed self-assembly and anion recognition properties of transition metal-based receptors." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269331.

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Shinde, Sudhirkumar A. [Verfasser], Björn [Akademischer Betreuer] Sellergren, and Frank [Gutachter] Schulz. "Urea based hosts for oxyanions prepared by molecular imprinting, applications in phospho- and sulfo-proteomics / Sudhirkumar A. Shinde. Betreuer: Björn Sellergren. Gutachter: Frank Schulz." Dortmund : Universitätsbibliothek Dortmund, 2013. http://d-nb.info/1104261537/34.

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3

Wiebler, James. "UREA HYDROLYSIS BY GUT BACTERIA: FIRST EVIDENCE FOR UREA-NITROGEN RECYCLING IN AMPHIBIA." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami152535331130121.

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4

Marlow, Jeffrey. "Detecting life on Mars through the study of organic host Mars analogues and Urey instrument development." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5943.

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The search for life on Mars is one of today’s most exciting and far-reaching scientific challenges. The European Space Agency’s ExoMars mission will renew the pursuit of signs of past or present life equipped with a range of analytical instruments: one such instrument will likely be Urey, a tool that will extract and analyze organic molecules. This thesis first seeks to contextualize the search for life through the use of analogue sites on Earth and ultimately works to optimize the spectrofluorometric detection of relevant organic molecules. Organic host analogues – sites on Earth where life faces similar challenges as potential martian life forms – aid in mission planning and data analysis. With these dual purposes in mind and the understanding that collaborative analogue use benefits all stakeholders, the Imperial College Mars Analogue Repository (ICMAR) was established. Samples from Iceland and the Middle Atlas mountains of Morocco were gathered to start the collection. As it grows, mission planners and scientists will have a centralized, well-characterized set of samples for astrobiological studies. Optimizing Urey’s spectrofluorometric detection of amino acids and polycyclic aromatic hydrocarbons (PAHs) was another primary aim of this study. Standard solutions were tested across a range of instrumental parameters and an ideal excitation wavelength was identified to optimize the detection of any organics present at the sampling site. The fluorescent interaction between molecules was also investigated to evaluate the instrument’s ability to detect and quantify complicated, multicomponent samples. Finally, natural organic-rich samples from England’s Blue Lias formation were tested to evaluate spectrofluorometric analysis of natural samples – a capability that will be crucial for in situ martian analysis. By highlighting the role of organic Mars analogues and optimizing the Urey instrument, this thesis enhances ExoMars’ ability to identify organic molecules and sets the stage for continued martian exploration.

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Chen, Jau-An, and 陳昭安. "The Research of Urea Groups as part of Host or Guest." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/78634884026689689692.

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博士
國立臺灣大學
化學研究所
94
There are three chapters in the thesis. The cooperative and selective lithium complexation of compounds 3 and 6 containing urea groups was discussed in the chapter 1. Compounds 3 and 6 form 1:2 complex with lithium ion cooperatively. The selective lithium complexation of compound 6 among ions belong to IA was found from fluorescence experiment. Urea and amide were used as guest molecule in the chapter 2. Dicarboxylate 36 shows three anodic waves and two cathodic waves in CV. The cathodic current decreased when urea and amide were added. The linear relationship of the concentration of analyte and 36, Ipc0 and Ipce was followed the equation below:[Analyte]/[36]0-{(Ipc0-Ipce)/Ipc0}=(1/K[36]0) {(Ipc0-Ipce)/Ipc0},the slope is binding constant K. The synthesis of cyclic chiral compounds R-56, S-56 and 79 containing urea groups was discussed in chapter 3.

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6

"New host lattices containing monocyclic oxocarbon anions, urea/thiourea and water molecules." 1998. http://library.cuhk.edu.hk/record=b5889665.

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by Chi-Keung Lam.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.
Includes bibliographical references (leaves 100-103).
Abstract also in Chinese.
Acknowledgments --- p.i
Abstract --- p.ii
摘要 --- p.iii
Table of contents --- p.iv
Index of compounds --- p.v
List of tables --- p.vi
List of figures --- p.vii
Chapter Chapter 1. --- Introduction
Chapter 1.1 --- Some aspects of urea/thiourea inclusion chemistry --- p.1
Chapter 1.2 --- General chemistry of monocyclic oxocarbons --- p.5
Chapter 1.2.1 --- Synthesis of monocyclic oxocarbons --- p.5
Chapter 1.2.2 --- Aromaticity of monocyclic oxocarbon anions --- p.20
Chapter 1.2.3 --- Reactions of monocyclic oxocarbons --- p.25
Chapter 1.3 --- Aim of the present research --- p.31
Chapter Chapter 2. --- Description of crystal structures
Chapter 2.1 --- Urea-anion inclusion compounds --- p.32
Chapter 2.1.1 --- Bis(tetra-n-propylammonium) squarate-urea-water (1/ 6/2) --- p.32
Chapter 2.1.2 --- Tetra-n-butylammonium hydrogen squarate-urea-water (1/1/1) --- p.38
Chapter 2.1.3 --- Bis(tetraethylammonium) squarate-tetraethylammonium hydrogen carbonate- urea-water (1/2/4/6) --- p.42
Chapter 2.1.4 --- Bis(tetra-n-propylammonium) croconate-urea-water (1/5/2) --- p.47
Chapter 2.2 --- Thiourea-anion inclusion compounds --- p.53
Chapter 2.2.1 --- Bis(tetraethylammonium) squarate-thiourea-water (1/4/ 2) --- p.53
Chapter 2.2.2 --- Bis(tetraethylammonium) squarate-thiourea (1/6) --- p.59
Chapter 2.2.3 --- Bis(tetra-n-propylammonium) squarate-thiourea-water (1/ 4/2) --- p.66
Chapter Chapter 3. --- Summary and discussion
Chapter 3.1 --- Urea/thiourea monocyclic oxocarbon anions inclusion compounds --- p.71
Chapter 3.2 --- Structural features and topological correlations of the host lattices --- p.72
Chapter 3.3 --- Hydrogen bonding and linkage modes of urea and thiourea molecules --- p.87
Chapter Chapter 4. --- Experimental
Chapter 4.1 --- Preparation of crystals --- p.91
Chapter 4.2 --- X-ray Crystallography --- p.93
References --- p.100
Appendix Atomic coordinates and thermal parameters of the new inclusion compounds --- p.104

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7

"Designed construction of hydrogen-bonded host lattices with urea/thiourea, guanidinium and selected anions." Thesis, 2009. http://library.cuhk.edu.hk/record=b6074746.

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Investigation on a series of hydrogen-bonded networks constructed with N-heteroaryl acids is described in Section 3.4. In this section, we focused on the connection modes within the heteroaryl dimer. The study of co-crystals and inclusion compounds based on 2-thiobarbituric acid (TBA) or trithiocyanuric acid (TCA) indicated that the dimer of TBA is present in all three crystals in the forms of ribbon, tetramer or separated dimer. In the case of 5-nitrobarbiturate, its dimer occurs in two ammonium salts and in three of its four thiourea complexes, but is absent in all three urea complexes.
Self-assembly of two-dimensional hydrogen-bonded honeycomb grids exhibiting the rosette motif has been conducted with the guanidinium cation and various anions as the building blocks, tetraalkylammonium ions of suitable bulk being employed as interlayer templates. It is noteworthy that the rosette layer constructed from three different trigonal-planar molecular components has been achieved. In addition, deviating from conventional topological design, the generation of new rosette layers, albeit highly distorted, has also been accomplished with 1,2-dithiosquarate and the dianionic form of 1,1'-biphenyl-2,2',6,6'-tetracarboxylate that do not conform to C3-symmetry. Although threefold molecular symmetry is regarded as a sacrosanct requirement for molecular building blocks in the construction of hydrogen-bonded rosette motif, this study shows that rosette motifs can be generated even if one of the building blocks does not have inherent threefold symmetry.
Study of compounds containing the deprotonated forms of Kemp's triacid (H3KTA) has revealed the chair or twist-boat conformation in six crystal structures. X-ray structural analysis showed that [C(NH2) 3+] · [C6H6(CH3) 3(COOH)2(COO-)] (2.2.2) exhibits a corrugated layer structure which mimics the rosette motif constructed from the guanidinium ion and the hydrogen carbonate dimer. The tricarboxylate form of Kemp's triacid KTA3- in 3[C(NH2) 3+] · [C6H6(CH3) 3(COO-)3] (2.2.4) registers a record number of eighteen acceptor hydrogen bonds involving the convergent N--H donor sites from nine guanidinium ions. The crystal structure of 3[(C2H5)4N+] · 20[C(NH 2)3+] · 11[C6H6(CH 3)3(COOH) (COO-)2] · [C6H6(CH3)3(COOH)2(COO -)]·17H2O (2.2.3) features a hydrogen-bonded aggregate with a centrosymmetric pseudo-octahedral arrangement of H2KTA- anions surrounding an inner core composed of eight guanidinium ions. The unusual twist-boat conformation of KTA3- is found in [(CH3)4N +] · 2[C(NH2)3+] · [C6H6(CH3)3(COO- )3] · 2H2O (2.2.6), which is stabilized by the co-existence of guanidinium and tetramethylammonium cations.
Systematic investigation on hydrogen-bonded supramolecular assembly using aromatic carboxylic acids bearing linear or bent skeletons with urea/guanidinium resulted in the formation of mainly R228 and R126 synthon motifs. In addition, isostructures were also constructed by varying the length of the linker between two carboxylate groups, as in naphthalene-2,6-dicarboxylate (2.3.2) and biphenyl dicarboxylate (2.3.3).
This thesis reports a systematic investigation on the generation of new inclusion compounds by the combined use of urea/thiourea, guanidinium ion and various organic anions as building blocks of hydrogen-bonded host lattices and selected quaternary ammonium ion as the enclosed guests.
Various acids bearing specific functional groups have been explored as structure building components, including boric acid, Kemp's triacid, heterocyclic (thio)urea derivatives, aryl and N-heteroaryl carboxylic acids and (dithio)squaric acid. All the co-crystals and inclusion compounds built of molecular components in the afore-mentioned categories have been characterized by single-crystal X-ray analysis. As a result, the complexes exhibit a rich variety of inclusion topologies, such as networks containing isolated cages, open channels, intersecting tunnels, double-layer systems, and sandwich-like as well as wave-like layer structures.
Han, Jie.
Adviser: Thomas C. W. Mak.
Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0337.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 204-218).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts in English and Chinese.

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Books on the topic "Urea hosts"

1

Ellam, Rob. 5. Physics heal thyself. Oxford University Press, 2016. http://dx.doi.org/10.1093/actrade/9780198723622.003.0005.

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Stable and radioactive isotopes are used extensively in diagnostic and therapeutic medical applications including studies of human body composition, energy balance, protein turnover, and metabolism. ‘Physics heal thyself: isotopes in medicine’ shows how ionizing radiation is key to a host of medical imaging techniques with radioactive isotopes widely used to target and kill cancer cells. Enriched isotopes are used as biological tracers; doubly labelled water in the diagnosis of type 2 diabetes; and 13C-labelled urea in diagnosing stomach and duodenal ulcers. Medical uses of ionizing radiation are manifold including X-ray imaging, radiotherapy with external X-ray beams, brachytherapy, targeted radionuclide therapy, single photon emission computed tomography, and positron emission tomography.

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2

Burdmann, Emmanuel A., and Vivekanad Jha. Rickettsiosis. Edited by Vivekanand Jha. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0193.

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Rickettsiae are obligate intracellular bacteria transmitted by arthropods to a vertebrate host. Clinically relevant rickettsioses have a similar clinical pattern, manifesting as an acute febrile disease accompanied by headache, articular and muscle pain, and malaise.Epidemic typhus is a worldwide distributed disease caused by the Rickettsia prowazekii, with a human louse as a vector. Data on epidemic typhus-related renal injury is extremely scarce.Murine typhus is caused by the Rickettsia typhi and has a rodent flea as the vector. It is one of the most frequent rickettsioses, and is usually a self-limited febrile illness. Proteinuria, haematuria, elevations in serum creatinine (SCr) and/or blood urea nitrogen (BUN) and AKI have been reported. The real frequency of renal involvement in murine typhus is unknown. Renal abnormalities recover after the infectious disease resolution.Scrub typhus, caused by the Orientia tsutsugamushi, has the Leptotrombidium mite larva as vector. It is endemic in the Tsutsugamushi triangle delimited by Japan, Australia, India, and Siberia. It can manifest either as a self-limiting disease or as a severe, life-threatening multiorgan illness. Early administration of adequate antibiotics is essential to prevent adverse outcomes. Proteinuria, haematuria, and acute kidney injury (AKI) are frequent.Tick-borne rickettsioses are caused by bacteria from the spotted fever group and have ticks as vectors. Rocky Mountain spotted fever (RMSF) is caused by Rickettsia rickettsii. It is the most severe of the spotted fever rickettsial diseases, causing significant morbidity and lethality. RMSF occurs in North, Central, and South America. Renal impairment is frequent in severe forms of RMSF. Mediterranean spotted fever is caused by Rickettsia conorii, and is endemic in the Mediterranean area. It is usually a benign disease, but may have a severe course, clinically similar to RMSF. Haematuria, proteinuria, increased serum creatinine, and AKI may occur. Japanese spotted fever is caused by Rickettsia japonica. Lethal cases are reported yearly and AKI has occurred in the context of multiple organ failure.

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Book chapters on the topic "Urea hosts"

1

Hollingsworth, Mark D., Kenneth D. M. Harris, William Jones, and John M. Thomas. "ESR and X-ray Diffraction Studies of Diacyl Peroxides in Urea and Aluminosilicate Hosts." In Inclusion Phenomena in Inorganic, Organic, and Organometallic Hosts, 273–77. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3987-5_48.

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2

Benetollo, Franco, Gabriella Bombieri, and Mary R. Truter. "Crystal Structures of 1:1 Complexes Between Urea and Two Crown Ether Derivatives of Phthalic Acid." In Inclusion Phenomena in Inorganic, Organic, and Organometallic Hosts, 165–68. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3987-5_26.

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3

Mak, Thomas C. W., and Qi Li. "Novel inclusion compounds with urea/thiourea/selenourea-anion host lattices." In Advances in Molecular Structure Research Volume 4, 151–225. Elsevier, 1998. http://dx.doi.org/10.1016/s1087-3295(98)80007-8.

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