Development of a liquid phase radioimmunoassay for the measurement of serum ferritin levels for the detection of Covid-19 in patients

Journal of Radioanalytical and Nuclear Chemistry - The aim of this study was the development and analytically validation of a radioimmunoassay system for the measurement of the serum ferritin...     

Nitrogen heterocyclic carbon-rich materials: synthesis and spectroscopic properties of dehydropyridoannulene macrocycles

A new series of nitrogen heterocyclic dehydroannulenes 1-3 have been synthesized and their macrocyclic structures assigned using spectroscopic methods. The chiral and planar ground state conformations of 1 and 3, respectively, were determined by semiempirical theoretical calculations. All dehydropyridoannulenes and precursors possessing four aromatic rings functioned as fluorescent chromophores. A detailed spectroscopic investigation into the cation-binding properties of 3 in dilute solution revealed a particularly selective photoluminescence quenching sensory response for Pd(II) ions. Cycle 3, as well as 1 and 2, also exhibited reversible proton-triggered luminescence quenching behavior. At higher concentrations, 3 afforded a coordination polymer precipitate with Ag(I) ions. Cycles 1 and 2 and precursors 15, 23, and 29 also undergo thermochemical reactions that may potentially lead to carbon-rich polymers. The physicochemical properties of 1-3 suggest that dehydropyridoannulenes may serve as a particularly versatile new class of ligands for the creation of novel heteroatom-containing carbon-rich materials with many potential applications in supramolecular materials science and nanotechnology.     

Quinquevalent tungsten as a reducing agent in potentiometric titrations : Estimation of ceric salts,bromate and ferricyanide

Quinquevalent tungsten can be further applied as a reducing agent for the potentiometric estimation of ceric salts, ferricyanide and bromate. Reduction of these oxidants takes place easily when they are present alone or in mixtures containing them together with ferric iron, dichromate or vanadate.     

Triterpenoid saponins from leaves of Hedera pastuchowii

Five new triterpenoid saponins, pastuchoside A (1), B (3), C (5), D (7) and E (9), were isolated from the leaves of Hedera pastuchowii. They have oleanolic acid or hederagenin as aglycone. The structures were established by NMR spectroscopy including gs (gradient selected)-COSY, gs-HSQC, gs-HSQC-TOCSY and gs-HMBC experiments, and mass spectrometry (ESI-HR-MS). Heptaoside saponins, compounds 1 and 3, are described for the first time in the genus Hedera.