Zakia Sultana

Oxidative stress, placental ageing-related pathologies and adverse pregnancy outcomes

Oxidative stress (OS), an imbalance between free radical generation and antioxidant defence, is recognized as a key factor in the pathogenesis of adverse pregnancy outcomes. Although OS is a common future of normal pregnancy, persistent, overwhelming OS leads to consumption and decline of antioxidants, affecting placental antioxidant capacity and reducing systems. The accumulation of OS causes damage to lipids, proteins and DNA in the placental tissue that induces a form of accelerated ageing. Premature ageing of the placenta is associated with placental insufficiency that prevents the organ meeting the needs of the foetus, and as a consequence, the viability of the foetus is compromised. This review summarizes the literature regarding the role of OS and premature placental ageing in the pathophysiology of pregnancy complications.

Is there a role for placental senescence in the genesis of obstetric complications and fetal growth restriction

The placenta ages as pregnancy advances, yet its continued function is required for a successful pregnancy outcome. Placental aging is a physiological phenomenon; however, there are some placentas that show signs of aging earlier than others. Premature placental senescence and aging are implicated in a number of adverse pregnancy outcomes, including fetal growth restriction, preeclampsia, spontaneous preterm birth, and intrauterine fetal death. Here we discuss cellular senescence, a state of terminal proliferation arrest, and how senescence is regulated. We also explore the role of physiological placental senescence and how aberrant placental senescence alters placental function, contributing to the pathophysiology of fetal growth restriction, preeclampsia, spontaneous preterm labor/birth, and unexplained fetal death.

Effect of chemical treatment on palm fibre reinforced polypropylene composites

The development of composites using lignocellulosic materials as reinforcing filler and thermoplastic polymers as matrices is currently at the centre of attention because of their low cost, lightweight, eco-friendliness and worldwide environmental awareness. In the present work, palm fibre reinforced polypropylene composites were manufactured using a single screw extruder and an injection moulding machine. Raw palm was chemically treated with benzene diazonium salt in alkali, acidic and neutral media separately to increase the compatibility of palm fibre with polypropylene matrix. Both raw and alkali, acidic and neutral media treated palm at various (15, 20, 25, 30 and 35 wt%) fibre loading were utilised during composite manufacturing. Microstructural analysis and mechanical testing were also conducted. Alkali media treated specimens yielded the best set of mechanical properties. Based on fibre loading, 30% fibre reinforced composites had the optimum set of mechanical properties among all composites manufactured.