Search results for "Measurements"

Complex Formation of the Uranyl (UO22+) Ion with the Diethylene Triaminopentaacetate (DTPA) Ligand at 25 °C in 3 M Sodium Perchlorate

2011

The complex formation between the uranyl (UO22+) ion and the diethylene triaminopentaacetate ligand (DTPA) has been investigated at 25 °C, in a 3 M sodium perchlorate medium. The overall protonation constants βjH of the free ligand have been previously determined in this ionic medium: six protonated species (HjA), with j ranging from 1 to 6, together with the free anion A5− have been identified in the concentration range from (3·10−3 to 13·10−3) mol·kg−1. Four complex species, H2UO2A−, HUO2A2−, UO2A3−, and UO2AOH4−, have been identified in the total uranyl concentration range from (1.1·10−3 to 5.7·10−3) mol·kg−1, and their overall stability constants determined, keeping the metal to ligand …

An anti-inflammatory ditriazine inhibiting leukocyte functions and expression of inducible nitric oxide synthase and cyclo-oxygenase-2.

2000

A ditriazine derivative (4,10-dichloropyrido[5,6:4,5]thieno[3,2-d':3, 2-d]-1,2,3-ditriazine (DTD)) inhibited neutrophil functions, including degranulation, superoxide generation, and leukotriene B(4) production, without any effect on 5-lipoxygenase activity. This compound reduced nitric oxide (NO) and prostaglandin E(2) production in mouse peritoneal macrophages stimulated with lipopolysaccharide, whereas no influence on the activity of inducible NO synthase, cyclo-oxygenase-2 or cyclo-oxygenase-1 was observed. DTD significantly reduced mouse paw oedema induced by carrageenan and also markedly reduced NO and prostaglandin E(2) levels in exudates from 24-h zymosan-stimulated mouse air pouch.…

Solid-phase synthesis and inhibitory effects of some pyrido[1,2-c]pyrimidine derivatives on leukocyte formations and experimental inflammation.

2001

A number of pyrido[1,2-c]pyrimidines bearing a nitrogen, oxygen, or sulfur functionality at C-1 were synthesized on solid-phase using the iminophosphorane methodology and tested for their effects on leukocyte functions in vitro and antiinflammatory activity. Compound 5c was found to be a strong scavenger of superoxide anion and an inhibitor of chemiluminescence induced by 12-O-tetradecanoylphorbol 13-acetate in human neutrophils. These pyrido[1,2-c]pyrimidines inhibited the generation of PGE(2) by COX-2 in RAW 264.7 macrophages stimulated with lipopolysaccharide. Compounds 7, 5f, 6, and 8 inhibited enzyme activity, whereas the remaining compounds also acted on the induction phase. In additi…

6-Dimethylamino 1H-pyrazolo[3,4-d]pyrimidine derivatives as new inhibitors of inflammatory mediators in intact cells.

2003

The synthesis of 6-dimethylamino 1H-pyrazolo[3,4-d]pyrimidines substituted at positions 1 and 4, and their effects on murine macrophage and human neutrophil functions are described. Several compounds and especially 4b-6b are potent inhibitors of PGE2 generation in murine macrophages. This action is related to a direct effect on COX-2 activity without affecting the enzyme expression. Some of these compounds also inhibited COX-1 and COX-2 in human monocytes and 4b showed selectivity for COX-2 inhibition. © 2003 Elsevier Science Ltd. All rights reserved.

Cloud top altitude retrieved from Lidar measurements during ACLOUD at 1 second resolution

2021

During the ACLOUD aircraft campaign (23.5.2017 - 26.6.2017) the AMALi Lidar was installed mostly nadir pointing. This dataset contains the cloud top altitude from those measurements (altitudes with a strong signal increase) as well as a cloud mask, derived from the optical depth of the column at 1 second resolution. The majority of the data was collected northwest of the Svalbard archipelago. More details on the campaign can be found in Wendisch 2018 and Ehrlich 2019 and here (https://home.uni-leipzig.de/~ehrlich/ACLOUD_wiki_doku). Please check the data documentation (https://download.pangaea.de/reference/108729/attachments/readme_documentation_AMALi_cloudtop.pdf) before using this dataset.

Chemi- and Bioluminescence of Cyclic Peroxides

2018

Bioluminescence is a phenomenon that has fascinated mankind for centuries. Today the phenomenon and its sibling, chemiluminescence, have impacted society with a number of useful applications in fields like analytical chemistry and medicine, just to mention two. In this review, a molecular-orbital perspective is adopted to explain the chemistry behind chemiexcitation in both chemi- and bioluminescence. First, the uncatalyzed thermal dissociation of 1,2-dioxetane is presented and analyzed to explain, for example, the preference for triplet excited product states and increased yield with larger nonreactive substituents. The catalyzed fragmentation reaction and related details are then exemplif…

Superconducting Solenoid System with Adjustable Shielding Factor for Precision Measurements of the Properties of the Antiproton

2019

Physical review applied 12(4), 044012 (2019). doi:10.1103/PhysRevApplied.12.044012

Comparison of line-by-line and band models of near-IR methane absorption applied to outer planet atmospheres

2012

Import OPTIWOS; International audience; Recent improvements in high spectral resolution measurements of methane absorption at wavenumbers between 4800 cm(-1) and 7919 cm(-1) have greatly increased the number of lines with known lower state energies, the number of weak lines, and the number of lines observed at low temperatures (Campargue, A., Wang, L, Kassi, S., Masat, M., Votava, O. [2010]. J. Quant. Spectrosc. Radiat. Trans. 111, 1141-1151; Campargue, A., Wang, L, Liu, A.W., Hu, S.M., Kassi, S. [2010]. Chem. Phys. 373, 203-210; Mondelain, D., Kassi, S., Wang, L.C. [2011]. Phys. Chem. Chem. Phys. 13, 7985-7996; Nikitin, A.V. et al. [2011a]. J. Mol. Spectrosc. 268, 93-106; Nikitin, A.V. et …

The influence of steric effects on the strength of some organic acids in toluene and water

A modular "toolbox" approach to flexible branched multimacrocyclic hosts as precursors for multiply interlocked architectures.

2008

Tetralactam macrocycles can be functionalized by a variety of cross-coupling reactions. A modular “toolbox” strategy is presented that allows 1) several tetralactam macrocycles to be covalently connected with each other or with a central spacer, 2) the macrocycles to be substituted with or connected to different chromophores, and 3) metal-coordination sites to be attached to the macrocycles. With this approach a series of different oligo-macrocyclic hosts was obtained with great structural diversity and enormous potential for further functionalization. Rotaxanes made on the basis of these macrocycles have been synthesized to demonstrate their utility in building more complex supramolecular …