The number of resonance structures (SC) for previously published concealed non-Kekuléan benzenoid hydrocarbons is determined. Using a simple computer program, analytical expressions for determining SC for various classes of non-Kekuléan (free-radical) benzenoid hydrocarbons are derived, and some properties of concealed non-Kekuléan benzenoid hydrocarbons are studied.

Exit block from a parasystolic focus is recognized when automatic discharges fail to become manifest during the excitable phase of the ventricular cycle. In the present study, an apparently complete exit block and a persistently concealed ventricular parasystole (VP) resulted from an exit refractory period (ExRP) longer than the sinus cycle length. Slowing of the heart rate caused the concealed...

Background Impaired renal function is often neglected in COPD patients. Considering that COPD patients usually have an ongoing prothrombotic state and systemic inflammation status, we investigated the association among them and explored the predictive value of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13), on concealed chronic renal failure (CRF) ...

The genesis of deeply buried deposits in the Duobaoshan ore district, largest porphyry-related Cu-Mo-Au field northeastern China, is not well understood and their exploration lacking because fine velocity structure this region comprehensively understood. Herein, first-arrival seismic travel times were picked along a deep reflection profile inverted using tomographic method to obtain detailed up...

Practical methods for determining the ultra-trace abundances of precious metals in geological materials are needed research into magmatic and hydrothermal processes to expand geochemical footprints concealed ore deposits. This study presents a new protocol Au, Ag, As, Pt Re mass fractions both volcanic glasses rock powders prepared as nano-powder pellets, through synthesis refinement published ...

BACKGROUND In elderly patients serum creatinine may be normal despite decreased glomerular filtration rate (GFR). The aim of this study was to evaluate the prevalence of this "concealed" renal failure, i.e., renal failure with normal serum creatinine levels, in elderly diabetic patients, and to verify whether it is a risk factor for adverse drug reactions (ADR) to hydrosoluble drugs. METHODS ...