Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FRUSTRATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed2002

New therapeutics that antagonize endothelin: promises and frustrations.

The discovery of endothelin--a highly potent endogenous vasoconstrictor - in 1988 has led to considerable efforts to develop antagonists of endothelin receptors that could have therapeutic potential in disorders including hypertension, heart failure and renal diseases. However, in general, the results of trials in humans have not mirrored the highly promising effects in animal disease models. Here, we discuss preclinical and clinical results with endothelin antagonists, and consider possible approaches to fully realizing the potential of endothelin antagonism.

Animals↗
PubMed2004

The pyrochlore family -- a potential panacea for the frustrated perovskite chemist.

Many known complex oxides of general formula A(2)B(2)X(7) adopt the pyrochlore structure, a key structure-type that has been shown to demonstrate a vast range of useful physical properties. Areas currently of much interest with respect to pyrochlores, include metal-insulator transitions, magnetic frustration/spin ices, magnetoresistance, superconductivity, ferroelectrics, O/F ionic conductivity, mixed conductivity, pigments and catalysis. We present some recent results on three types of pyrochlore materials that show unusual magnetic, optical and electronic behaviours associated with subtle structural and compositional changes. High-resolution powder neutron diffraction studies of the superconducting Cd(2)Re(2)O(7) and the ferroelectric Cd(2)Nb(2)O(7) have been undertaken on material cooled below room temperature. Both Cd(2)Re(2)O(7) and Cd(2)Nb(2)O(7) exhibit small structure distortions, in each case involving a distortion from a cubic unit cell, on cooling below approximately 180 K and possible models that can be used to describe the low-temperature structures and associated atomic displacements are developed and described in this article. A range of materials of the general formula Ca(1-x)Ln(x)TaO(2-x)N(1+x), x= 0.5 and x= 1, Ln = La-Yb have been synthesised and shown to adopt pyrochlore and/or perovskite structures. The absorption spectra of these materials are discussed in terms of their structures and compositions.

Journal Article↗
PubMed2006

A spin-frustrated star-shaped heterotetranuclear CrIIIMnII3 species and its magnetic and HF-EPR measurements.

A tetranuclear complex [Cr(III)Mn(II)(3)(PyA)(6)Cl(3)] 1 containing pyridine-2-aldoximato monoanion, PyA, has been structurally and magnetochemically characterized. The compound is a rare example of a tetranuclear star-shaped metal topology containing pyridine-2-aldoximato ligands. Static magnetic studies have demonstrated very weak antiferromagnetic exchange interactions between the paramagnetic centers (S(Cr) = 3/2 and S(Mn) = 5/2) resulting in closely spaced low-lying levels, which undergo splitting and crossing. Preliminary high-field EPR measurements (20 < nu < 388 GHz) indicate the presence of zero-field splitting D of the order of 0.7 cm(-1).

Chromium↗