The question of whether the class of decision problems that can be solved by deterministic polynomial-time algorithms (P ) is equal to the class of decision problems that can be solved by nondeterministic polynomial-time algorithms (NP) has been open since it was first formulated by Cook, Karp, and Levin in 1971. In this paper, we prove that they are not equal by showing that any algorithm that...

In 1955, John Nash sent a remarkable letter to the National Security Agency, in which— seeking to build theoretical foundations for cryptography—he all but formulated what today we call the P ? = NP problem, considered one of the great open problems of science. Here I survey the status of this problem in 2017, for a broad audience of mathematicians, scientists, and engineers. I offer a personal...

Background This study aimed to assess the protective effects of saturejakhuzistanica (SJKH) on sperm quality parameters in the Nonyl phenol (NP) - treated mice. MaterialsAndMethods In present experimental study, 32 young adult male mice (8-12 weeks) were randomly divided into four groups including control and test groups. The control group received corn oil orally, and the test groups were trea...

conclusions the rabies virus np could be extracted and purified in an appropriate amount from infected cell culture. the results of sds-page analysis showed that the intact rabies virus np had been purified properly and thus could be used for further steps to produce the specific diagnostic rabies conjugate. results the volume of the lysate was 15 ml and it became 2.5 ml after purification, wit...

background: neuropathic pain (np) is a serious suffering medical condition that frequently leads to disability and life style changes. although the exact mechanisms of np are still unknown, recently the role of reactive oxygen species (ros) reported as an important factor for np. apoptosis, increase of atp production and reduction of antioxidants are also the other factors influencing in np. th...