Search results for "derivati"
showing 10 items of 1360 documents
Response of isolated human ventricular myocardium to cyclic AMP and its dibutyryl derivative.
1974
The contractile responses to c-AMP and DB-c-AMP were studied in isolated electrically stimulated human papillary muscle strips. C-AMP (1×10−4 to 1×10−3 M) had no effect on contractile force in all of 6 human papillary muscle preparations studied. In contrast, DB-c-AMP (10−4 to 5×10−3 M) produced a concentration-dependent and reversible positive inotropic effect which was associated by a decrease in time to peak force and in relaxation time and which was not inhibited by 10−6 M propranolol. The possibility of a clinical applicability of DB-c-AMP is discussed.
B-type natriuretic peptide trend predicts clinical significance of worsening renal function in acute heart failure
2019
Aims In acute heart failure (AHF), relationships between changes in B-type natriuretic peptide (BNP) and worsening renal function (WRF) and its prognostic implications have not been fully determined. We investigated the relationship between WRF and a decrease in BNP with in-hospital and 1-year mortality in AHF. Methods and results The Acute Kidney Injury NGAL Evaluation of Symptomatic heart faIlure Study (AKINESIS) was a prospective, international, multicentre study of AHF patients. Severe WRF (sWRF) was a sustained increase of >= 44.2 mu mol/L (0.5 mg/dL) or >= 50% in creatinine, non-severe WRF (nsWRF) was a non-sustained increase of >= 26.5 mu mol/L (0.3 mg/dL) or >= 50% in cr…
Mappings of Finite Distortion:¶Discreteness and Openness
2001
We establish a sharp integrability condition on the partial derivatives of a mapping with L p -integrable distortion for some p>n− 1 to guarantee discreteness and openness. We also show that a mapping with exponentially integrable distortion and integrable Jacobian determinant is either constant or both discrete and open. We give an example demonstrating the preciseness of our criterion.
Rationally integrable vector fields and rational additive group actions
2016
International audience; We characterize rational actions of the additive group on algebraic varieties defined over a field of characteristic zero in terms of a suitable integrability property of their associated velocity vector fields. This extends the classical correspondence between regular actions of the additive group on affine algebraic varieties and the so-called locally nilpotent derivations of their coordinate rings. Our results lead in particular to a complete characterization of regular additive group actions on semi-affine varieties in terms of their associated vector fields. Among other applications, we review properties of the rational counterpart of the Makar-Limanov invariant…
Ion pair recognition receptor based on an unsymmetrically 1,1'-disubstituted ferrocene-triazole derivative.
2012
The ferrocene-triazole derivative 4, available from 1,1'-bis(diazido)ferrocene by sequential functionalization through click-type chemistry and the Staudinger reaction, is elaborated as a lab-on-a-molecule for the selective sensing of HP(2)O(7)(3-) and Hg(2+). Receptor 4 behaves as a ratiometric fluorescent probe for HP(2)O(7)(3-) with a good selectivity over other anions, whereas in the presence of Hg(2+) it modifies the fluorescent emission of the pyrene unit, acting as a selective on-off fluorescent sensor for Hg(2+) with a low detection limit. The most salient feature of compound 4 is its behavior as an excellent electrooptical ion pair recognition receptor able to simultaneously recogn…
Cytotoxic Activity of Some Natural and Synthetic ent-Kauranes
2007
Atractyligenin (1) and several synthetic derivatives were tested and found to be active against tumor cell replication. Compound 1 was readily converted to the 2,15-diketo (3) or 15-keto (4) derivatives, which contain an alpha,beta-unsaturated ketone. Compounds 3 and 4 showed significant cytotoxic activity against all six tested cancer cell lines and were most potent against 1A9 ovarian cancer cells with EC50 values of 0.2 and 0.3 microM, respectively. These two 1-analogues are promising lead compounds for further investigation.
Fluorinated Heterocyclic Compounds. An Effective Strategy for the Synthesis of Fluorinated Z-Oximes of 3-Perfluoroalkyl-6-phenyl-2H-1,2,4-triazin- 5-…
2005
The reaction of 3-benzoyl-5-perfluoroalkyl-1,2,4-oxadiazoles with hydrazine has been investigated, evidencing the possibility of competitive reaction paths. Nucleophilic addition of the hydrazine to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure with enlargement, leads with high yield and in very mild experimental conditions to the formation of Z-oximes of 3-perfluoroalkyl-6-phenyl-2H-1,2,4-triazin-5-ones (11a-c) as major products of the reaction. In turn, the hydrazine can attack the electrophilic carbonyl carbon giving 4-perfluoroacylamino-5-phenyl-2H-1,2,3-triazoles (13a-c) through the well-known Boulton-Katritzky rearrangement of the inter…
Fenoksietanola derivatizācija ar nitrobenzoilhlorīdu lodīšu pildspalvas tintes matricā
2016
Fenoksietanola derivatizācija ar nitrobenzoilhlorīdu lodīšu pildspalvas tintes matricā. Teļeševa L., zinātniskais vadītājs Dr. ķīm., asoc. prof. Mekšs P. Maģistra darbs. 70 lappuse, 44 attēls, 16 tabulas, 99 literatūras avoti, 4 pielikumi. Latviešu valodā. Darbā apskatīts lodīšu pildspalvu tintes sastāvs un tā izpētes metodes – augstefektīva šķidruma hromatogrāfija un gāzes hromatogrāfija. Darbā piemēklēti 2-fenoksietanola derivatizēcijas apstākļi un identificēts iespējamais derivtizācijas produkts. Kā paraugi tika izvēlētas 3 lodīšu pildspalvas. 2-fenoksietanola un tā derivatizācijas produkta noteikšanai izmantota metode bija augstefektīva šķidruma hromatogrāfija (AEŠH).
ChemInform Abstract: Photochemical Transformations of Some Neoclerodane and Labdane Diterpene Ketones.
2010
Some neoclerodane (2–4) and labdane (5 and 6) diterpene ketones having a β- or γ-hydroxy function, an α-epoxy group, or an α-olefinic double bond have been irradiated at λ = 313 nm in dry solvents (benzene or methanol). Fruticolone (2) yielded the naturally occurring 5,6-seco-neoclerodan-6,1α-olide derivative fruticolide (1), while hispanolone (5) gave the δ-lactone 8, both transformations involving a Norrish type I photoreaction. The α,β-unsaturated ketone derivative 4 was transformed into 7 by a stereoselective intramolecular [2+2] cycloaddition reaction involving its furanic 13(16)-double bond. Finally, the α-epoxy ketone 6 was rearranged to the 10(98)abeo-labda-7,9-dione derivative 10. …
Synthesis and Chemical physical characterization of a new series of hydroxil, acetylacetonate lanthanide (III) – ditungsten decacarbonyl hydride comp…
2004
A novel series of the heterometallic lanthanide(III) ionic cluster complexes of general formula Ln 9 (acac) 16 (OH) 10 [W 2 (CO) 10 (μ-H)] with Ln = Sm (la), Eu (1b), Gd (1c), Dy (1d), and Yb (le) was prepared and characterized by FTIR, 1 H NMR spectroscopy and single crystal X-ray analysis. The cluster series was obtained by reaction in ethanol solution of the 2,4-pentanedionate hydrate of lanthanide(III), Ln(acac) 3 .3H 2 O, with the hydridic ditungsten decacarbonyl, [W 2 (CO) 10 (μ-H)] - . X-ray analysis showed that the complexes la-le are isostructural. The complete structural characterization of the Eu derivative (1b) shows, similarly to their chromium derivative analogues, a square an…