Tungsten filaments used as sources of electrons in a low-temperature liquid or gaseous helium environment have remarkable properties of operating at thousands of degrees kelvin in surroundings at temperatures of order 1 K. We provide an explanation of this performance in terms of important changes in the thermal transport mechanisms. The behavior can be cast as a first-order phase transition.

Gaseous mediators are important signaling molecules with properties that differ from other, larger signaling molecules. Small gaseous mediators readily cross cell membranes and can access sites on target molecules that would be inaccessible to bulkier molecules. They have a variety of signaling mechanisms, some well understood, some not. The family of gasotransmitters is growing, well known mem...

The central nervous system (CNS) in concert with the heart and vasculature is essential to maintaining cardiovascular (CV) homeostasis. In recent years, our understanding of CNS control of blood pressure regulation (and dysregulation leading to hypertension) has evolved substantially to include (i) the actions of signaling molecules that are not classically viewed as CV signaling molecules, som...

Intracellular redox imbalance is mainly caused by overproduction of reactive oxygen species (ROS) or weakness of the natural antioxidant defense system. It is involved in the pathophysiology of a wide array of human diseases. Hydrogen sulfide (H2S) is now recognized as the third "gasotransmitters" and proved to exert a wide range of physiological and cytoprotective functions in the biological s...

Hydrogen sulfide (sulfide, H(2)S) is a colorless, water-soluble gas with a typical smell of rotten eggs. In the past, it has been investigated for its role as a potent toxic gas emanating from sewers and swamps or as a by-product of industrial processes. At high concentrations, H(2)S is a powerful inhibitor of cytochrome c oxidase; in trace amounts, it is an important signaling molecule, like n...