Respiratory gaseous exchange occurs between the interior of an organism and the environment. In all animals with a vascular system, in which the blood transports respiratory gases, there is a twofold gaseous exchange within actively respiring tissues...

Gas exchange or respiration takes place at a respiratory surface - a boundary between the external environment and the interior of the body. For unicellular organisms the respiratory surface is simply the cell membrane, but for large organisms it...

The world's largest natural gas exporting countries plan to establish a high-level group on gas pricing, the Russian energy minister said Monday, though his Iranian and Qatari counterparts denied the producers aim to establish a cartel.Europe and the United States have expressed worries that the...