Search results
Results from the WOW.Com Content Network
In chemistry, a molecule experiences strain when its chemical structure undergoes some stress which raises its internal energy in comparison to a strain-free reference compound. The internal energy of a molecule consists of all the energy stored within it. A strained molecule has an additional amount of internal energy which an unstrained ...
For example, an individual would prefer to know when they have a deadline ahead of time in order to prepare for it in advance, rather than find out about the deadline the day of. In knowing that there is a deadline ahead of time, the intensity of the stressor is smaller for the individual, as opposed to the magnitude of intensity for the other ...
For example, students who are taking exams show weaker immune responses if they also report stress due to daily hassles. [45] While responses to acute stressors typically do not impose a health burden on young, healthy individuals, chronic stress in older or unhealthy individuals may have long-term effects that are detrimental to health.
This category includes grief, anxiety, depression, post-traumatic stress and other forms of moral injury and mental disorders caused or inflamed by war. Between the start of the Afghan war in October 2001 and June 2012, the demand for military mental health services skyrocketed, according to Pentagon data. So did substance abuse within the ranks.
Prolonged stress can disturb the immune, digestive, cardiovascular, sleep, and reproductive systems. [17] For example, it was found that: Chronic stress reduces resistance of infection and inflammation, and might even cause the immune system to attack itself. [27] Stress responses can cause atrophy of muscles and increases in blood pressure. [28]
Experimentally, stress relaxation is determined by step strain experiments, i.e. by applying a sudden one-time strain and measuring the build-up and subsequent relaxation of stress in the material (see figure), in either extensional or shear rheology. a) Applied step strain and b) induced stress as functions of time for a viscoelastic material.
Oxidative stress mechanisms in tissue injury. Free radical toxicity induced by xenobiotics and the subsequent detoxification by cellular enzymes (termination).. Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. [1]
Chemistry, not moral failing, accounts for the brain’s unwinding. In the laboratories that study drug addiction, researchers have found that the brain becomes conditioned by the repeated dopamine rush caused by heroin. “The brain is not designed to handle it,” said Dr. Ruben Baler, a scientist with the National Institute on Drug Abuse.