How marijuana affects the mind. Marijuana reaches the same pleasure centers in the brain that are targeted by heroin, cocaine and alcohol. Depending on the quantity, quality and method of consumption, marijuana can produce a feeling of euphoria â or high â by stimulating brain cells to release the chemical dopamine.
History of Penicillin. Originally noticed by a French medical student, Ernest Duchesne, in 1896. Penicillin was re-discovered by bacteriologist Alexander Fleming working at St. Mary's Hospital in London in 1928. He observed that a plate culture of Staphylococcus had been contaminated by a blue-green mold and that colonies of bacteria adjacent to the mold were being dissolved.
Penicillin (PCN or pen) is a group of antibiotics which include penicillin G (intravenous use), penicillin V (oral use), procaine penicillin, and benzathine penicillin (intramuscular use).They are derived from Penicillium fungi.hile the number of penicillin-resistant bacteria is increasing, penicillin can still be used to treat a wide range of infections caused by certain susceptible bacteria, including Streptococci, Staphylococci, Clostridium, and Listeria genera.