Results 91 to 100 of about 73,935 (281)

Pyrimidine Acyclo-C-Nucleosides by Ring Transformations of 2-Formyl-L-arabinal

Molecules, 2005
The protected 2-formyl-L-arabinal 2 reacted with thiourea and cyanamide in the presence of sodium hydride to afford via ring transformations the 5-[1R,2S-1,2- bis(benzyloxy)-3-hydroxypropyl]-1,2-dihydropyrimidines 3 and 4, respectively.
Klaus Peseke, Manfred Michalik, Holger Feist, Ahmed Bari   +3 more
doaj   +1 more source

Lie Markov models with purine/pyrimidine symmetry [PDF]

, 2013
Continuous-time Markov chains are a standard tool in phylogenetic inference. If homogeneity is assumed, the chain is formulated by specifying time-independent rates of substitutions between states in the chain.
Fernández-Sánchez, Jesús, Jarvis, Peter D., Sumner, Jeremy G., Woodhams, Michael D.   +3 more
core   +2 more sources

Mechanism of Hydrogen Sulfide Generation and Prevention Strategies in Oil and Gas Fields: A Case Study of the Sickle Bay Operation Area

Asia-Pacific Journal of Chemical Engineering, EarlyView.
ABSTRACT To address the persistent exceedance of hydrogen sulfide (H2S) concentrations and the limited effectiveness of existing treatments in the Sickle Bay oil production area, this study deeply analyzes the mechanism of H2S generation in the Sickle Bay oil production area and proposes targeted prevention and control strategies. The results show that
Bo Lei, Yao‐long Li, Bao‐ping Bai, Xiang‐de Zhang, Guan‐tao Shi, Yong‐long Xie, Chen‐xiao Hou, Cong‐Yu Ke   +7 more
wiley   +1 more source

Diverse Methods with Stereoselective Induction in the Asymmetric Biginelli Reaction

Molecules
The relevance of the asymmetric Biginelli reaction (ABR) has been increased in this century, due to the pharmacological application of its products. This review focuses predominantly on articles published in the period from 2015 to 2024 on asymmetric ...
Marcos Díaz-Fernández, Manuel Algarra, Saturnino Calvo-Losada, José-Joaquín Quirante, Francisco Sarabia, María-Soledad Pino-González   +5 more
doaj   +1 more source

Inosine‐Triphosphate‐Pyrophosphatase Activity as a Potential Predictor of Methotrexate Remission in Juvenile Idiopathic Arthritis

Arthritis &Rheumatology, EarlyView.
Objective Methotrexate (MTX) is the first‐line therapy for juvenile idiopathic arthritis (JIA), but up to 40% of patients do not respond to it. Low inosine triphosphate pyrophosphatase (ITPA) activity has been associated with reduced clinical remission. We investigated the role and underlying mechanisms of ITPA in vitro. Methods ITPA enzymatic activity
Sofia Sindici Forgiarini, Marianna Lucafò, Debora Curci, Davide Selvestrel, Valentina Moressa, Sofia Pagarin, Barbara Bellich, Martina Franzin, Alberto Tommasini, Mara L. Becker, Laura B. Ramsey, Susan D. Thompson, Carl D. Langefeld, Federica Corba, Edoardo Marrani, Gabriele Simonini, Gabriele Stocco, Giuliana Decorti, Andrea Taddio, Serena Pastore   +19 more
wiley   +1 more source

The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

Beilstein Journal of Organic Chemistry, 2014
An extension of the substrate scope of the Flögel-three-component reaction of lithiated alkoxyallenes, nitriles and carboxylic acids is presented. The use of dicarboxylic acids allowed the preparation of symmetrical bis(β-ketoenamides) from simple ...
Mrinal K. Bera, Moisés Domínguez, Paul Hommes, Hans-Ulrich Reissig   +3 more
doaj   +1 more source

Tissue‐Specific and Spatially Dependent Metabolic Signatures Perturbed by Injury in Male and Female Mice

Arthritis &Rheumatology, EarlyView.
Objective Osteoarthritis, the leading cause of disability worldwide, disproportionately affects women, yet sex remains an overlooked determinant. This disparity stems from sex‐specific differences in injury susceptibility—a major risk factor for disease.
Hope D. Welhaven, Avery H. Welfley, Priyanka P. Brahmachary, Mark Greenwood, Donald F. Smith, Brian Bothner, Ronald K. June   +6 more
wiley   +1 more source

N‐heterocyclic carbene‐based tetradentate Pt(II) phosphors for blue organic light‐emitting diodes: Molecular design, photophysics, and device performance

Bulletin of the Korean Chemical Society, EarlyView.
Structure‐oriented design of NHC‐based tetradentate Pt(II) complexes offers narrowband deep‐blue emission for OLEDs. This review highlights how steric shielding and electronic modulation regulate intermolecular interactions, excited‐state dynamics, and device performance, outlining design principles and outlines toward efficient and durable blue ...
Mingi Kim, Chan Hee Ryu, Kang Mun Lee
wiley   +1 more source

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

Beilstein Journal of Organic Chemistry, 2016
The design, development and application of an efficient procedure for the concise synthesis of the 1,3-syn- and anti-tetrahydropyrimidine cores of manzacidins are reported.
Sebastian Bretzke, Stephan Scheeff, Felicitas Vollmeyer, Friederike Eberhagen, Frank Rominger, Dirk Menche   +5 more
doaj   +1 more source

DNA Nucleobase Synthesis at Titan Atmosphere Analog by Soft X-rays

, 2009
Titan, the largest satellite of Saturn, has an atmosphere chiefly made up of N2 and CH4 and includes traces of many simple organic compounds. This atmosphere also partly consists of haze and aerosol particles which during the last 4.5 gigayears have been
Abbate M., Abe I., Basile B., Coll P., d’Hendecourt L. B., Gerakines P. A., Gibb E. L., Glaser R., Grasset O., Griffith C. A., Gueymard C. A., Imanaka H., Imanaka H., Kerkhof O., Khare B. N., Khare B. N., Khare B. N., Kobayashi K., Kobayashi K., Kobayashi K., Kobayashi K., Lappi S. E., Lorenz R. D., Lowe C. U., McDonald G. D., McGuigan M., Miller S. L., Mitri G., Moore M. H., Neish C. D., Nuevo M., Oró J., Oró J., Oró J., Pietrogrande M. C., Pilling S., Ponnamperuma C., Pullman B., Sagan C., Tran B. N., Tran B. N., Wakamatsu H., Wang F., Yamada Y., Yamanashi H., Yuasa S.   +45 more
core   +2 more sources