The ( R )-(−)- enantiomer of modafinil, known as armodafinil , was also subsequently found to act as a D 2 High receptor partial agonist , with a K i of 16 nM, an intrinsic activity of 48%, and an EC 50 of 120 nM, in rat striatal tissue.  The ( S )-enantiomer is inactive with respect to the D 2 receptor.  Modafinil has been found to directly inhibit the firing of midbrain dopaminergic neurons in the ventral tegmental area and substantia nigra of rats via activation of D 2 receptors. 
On the other hand, there are instances which show the problems with improved and advanced technology or the solution for one problem with the help of technology is giving rise to another problem. Instead of taking care personally we are sending sms or giving a call on important occasions which were attended personally in olden days. With the use of same internet children are getting addicted to online games and their physical activities and exercises are becoming considerably less. The same social networks are creating rivalry between best friends and couples are getting divorced. The same aviation technology is giving health problems for their workers and creating serious environmental threats. With the heavy usage of fertilizers soil is losing its natural fertility and several varieties of plants became extinct.
percent of people found it difficult to get away from the Internet for about a number of days at a time, based on the statistic given by Stanford University. An interesting fact is that males are more likely to addict to the Internet, based on a research from the University of Lowa  . Not only being lured by these above factors, many students and teenagers come to the Internet as a way to hide from the real world. The pressure from parents’ expectation, from studying or even bullying scares them severely. They feel more comfortable and safer when living in a fiction world created on the Internet. The dangerous problem of internet addiction is not only about their life tendency but also their health. A study published on March 12, 2010, has shown a positive relationship between the use of the Internet and depression  . Specifically, people who are addicted to the Internet will be more likely to get depressed than normal people. According to Hilarie Cash, an American psychotherapist recommended that 8-10% of American teenagers get addicted to the Internet. This number means that approximately 2 million teenagers become depend on this system around the United States alone. It is a true alarm for people to recognize these negative effects of Internet on students and teenagers. If you want to know more about depression, a negative impact of Internet, click at Consequences of Depression