Depending on which part of the nervous system is affected, symptoms could include headache, dizziness, memory loss, numbness, pain, vision problems, and difficulty walking. Mount Sinaiâs NeuroAIDS Program specializes in diagnosing and treating the full range of HIV-related neurological disorders.
Many greenhouse gases occur naturally in the atmosphere, such as carbon dioxide, methane, water vapor, and nitrous oxide, while others are synthetic. Those that are man-made include the chlorofluorocarbons (CFCs) , hydrofluorocarbons (HFCs) and Perfluorocarbons (PFCs), as well as sulfur hexafluoride (SF 6).
The abundances of the noble gases decrease as their atomic numbers increase. Helium is the most plentiful element in the universe except hydrogen. All the noble gases are present in Earthâs atmosphere and, except for helium and radon, their major commercial source is the air, from which they are obtained by liquefaction and fractional distillation.