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Sami Ahmad Khan

    Dr. Sami Ahmad Khan is a contemporary author whose work delves into the intersection of technology and culture. His narratives often explore themes of identity and societal shifts, presented through a unique speculative lens. Khan's writing is characterized by its thoughtful engagement with current issues and its ability to craft compelling, genre-bending stories. Readers can expect works that are both intellectually stimulating and engaging.

    Oxidative Stress and Antioxidant Defenses in Biology
    Magnetic Field Assisted Finishing
    • The text details out a wide range of magnetic field assisted finishing processes in a comprehensive manner. It will be an ideal reference text for graduate students and professionals in the fields of mechanical engineering, aerospace engineering, production engineering, and industrial engineering.

      Magnetic Field Assisted Finishing
    • The ground-state of molecular oxygen, O , is essential to many 2 indispensible metabolic processes of all aerobic life forms ranging from prokaryotes, protists, plants, and fungi to animals. Research by mammalian toxicologists and clinicians has unravelled persua­ sive evidence that O dependence imposes universal toxicity to all 2 aerobic life processes. The basis of this paradox is that one-electron reduction of O2 generates the superoxide anion free radical, 0;-, from numerous biological sources; for example, redox-active autoxidizable molecules such as catecholamines, oxidoreductases, and subcellular organelles such as mitochondria, endoplasmic reti'C­ ulum (microsomes), nuclei, and chloroplasts. Oxygen is also acti­ vated in biologically relevant photosensitizing reactions to highly re­ active singlet oxygen, 10 , 2 In all biological systems, 0;- undergoes further reduction to H 0 2 2 via Fenton reaction to the hydroxyl radical, ·OH. These, and some other forms of activated O , constitute reactive oxygen species (ROS) 2 and/or metabolites (ROM). Both 'OH and 10 are the most reactive 2 forms of ROS known and among their deleterious reactions are ox­ idation of proteins, DNA, steroidal compounds, and peroxidation of the cell membrane's unsaturated lipids to form unstable hydro­ peroxides. Their many breakdown products include malondialde­ hyde and hydroxynonenals that are themselves highly reactive and threaten cellular integrity and function. More importantly, they de­ compose to free radicals that can continue to propagate the vicious lipid peroxidation chain reaction. This is the so-called endogenous oxidative stress with which all aerobic organisms must cope.

      Oxidative Stress and Antioxidant Defenses in Biology