Cardiac pacemaking is controlled by a mixed Na(+)/K(+) current named I(f), which is activated by hyperpolarized membrane potentials. Recently, a family of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels has been cloned. The members of this family exhibit the general features of I(f) channels. This review describes the molecular diversity of the HCN channel family and t...

Deuterated hydrogen cyanide (DCN) was detected in a comet, C/1995 O1 (Hale-Bopp), with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred deuterium/hydrogen (D/H) ratio in hydrogen cyanide (HCN) is (D/H)HCN = (2.3 +/- 0.4) x 10(-3). This ratio is higher than the D/H ratio found in cometary water and supports the interstellar origin of cometary ices. The observed val...

Hyperpolarization-activated cation currents, termed If, Ih, or Iq, were initially discovered in heart and nerve cells over 20 years ago. These currents contribute to a wide range of physiological functions, including cardiac and neuronal pacemaker activity, the setting of resting potentials, input conductance and length constants, and dendritic integration. The hyperpolarization-activated, cati...

We have observed the 3-2 transitions of DCN and HC 15 N in a number of hot molecular cores previously surveyed by us with the interesting result that the DCN/HCN ratio is low, a few times 10 −3 , in the hot cores. The abundance ratio of DCN/HCN is derived both 'on-core' and 'off-core' and, in general is larger at the 'off-core' positions. Comparision with chemical models of these sources indica...

Ideal "smart" nanoparticles for drug delivery should enhance therapeutic efficacy without introducing side effects. To achieve that, we developed a drug delivery system (HCN) based on a polymer-drug conjugate of poly[2-(pyridin-2-yldisulfanyl)]-graft-poly(ethylene glycol) and camptothecin with an intracellularly cleavable linker and human epidermal growth factor receptor 2 (HER2) targeting liga...

We present the first high-resolution, ground-based observations of HCN and C2H2 toward the T Tauri binary star system GV Tau. We detected strong absorption due to HCN 3 and weak C2H2 [ 3 and 2 þ ( 4 þ 5)0þ] absorption toward the primary (GV Tau S) but not the infrared companion. We also report CO column densities and rotational temperatures, and present abundances relative to CO of HCN/CO 0:6% ...

Hyperpolarization and Cyclic Nucleotide (HCN) -gated channels represent the molecular correlates of the "funny" pacemaker current (I(f)), a current activated by hyperpolarization and considered able to influence the sinus node function in generating cardiac impulses. HCN channels are a family of six transmembrane domain, single pore-loop, hyperpolarization activated, non-selective cation channe...

Hyperpolarization-activated cyclic nucleotide-modulated (HCN) ion channels regulate the spontaneous firing activity and electrical excitability of many cardiac and neuronal cells. The modulation of HCN channel opening by the direct binding of cAMP underlies many physiological processes such as the autonomic regulation of the heart rate. Here we use a combination of X-ray crystallography and ele...

Please note that this opinion replaces the earlier version which contained an error in the 'conclusion and recommendation' section on page. 23. SUMMARY The Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food is asked to evaluate substances used as flavourings or present in flavourings or present in other food ingredients with flavouring properties...

Although high levels of KCN (53 micromoles per gram fresh weight of seed, corresponding to 3.2 millimolar) failed to block germination of lettuce seeds incubated in covered Petri dishes, the same levels totally blocked germination in sealed dishes. Inhibition was reversed by removing the seal. Placement of KCN remote from seeds also blocked germination in closed systems. Cyanide effectiveness w...