Efect of maleated anhydride on mechanical properties of rice husk filler reinforced PLA Matrix Polymer Composite

Polylactic acid (PLA) formulated from corn starch has a bright potential to replace the non-renewable petroleum-based plastics. The combination of PLA and natural fbre has gained interest due to its unique performance, as reported in many researches and industries. Meanwhile, rice husk produced as the by-product of rice milling can be utilised, unless it is turned completely into waste. Therefore, in the present study, the rice husk powder (RHP) was used as a fller in the PLA, so to determine the infuence of the fller loading on the mechanical properties of the PLA composite. A coupling agent was selected for treatment from two options, i.e., maleic anhydride polypropylene (MAPP) and maleic anhydride polyethylene (MAPE), by applying the agents with various loading contents, such as 2, 4 and 6 wt%. The composite was fabricated by using the hot compression machine. Both the treated and untreated RHP–PLA composites were characterised via the tensile, fexural and impact strength tests. The increase in the RHP loading content led to the decrease in the tensile and fexural strengths. The applications of the coupling agents (MAPE and MAPP) did not improve the tensile and impact strengths, but the fexural strength was enhanced

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Combined exercise training reduces blood pressure, arterial stiffness, and insulin resistance in obese prehypertensive adolescent girls

Childhood obesity is strongly linked to pathological processes for cardiovascular diseases in later adulthood. Obese adolescent girls with high blood pressure (BP) are reported to have increased arterial stiffness, which is associated with the development of hypertension and atherosclerosis. The present study sought to examine the impact of combined resistance and aerobic exercise (CRAE) training on BP, brachial-ankle pulse wave velocity (baPWV), insulin resistance (IR), and body composition in obese prehypertensive girls. Forty girls (age, 15 ± 1 years; systolic BP, 132 ± 2 mmHg, diastolic BP, 80 ± 5 mmHg) were randomly assigned to either a combined exercise (EX, n = 20) or no exercise group (CON, n = 20). The EX group performed CRAE for 12 weeks, 3 times per week. BP, baPWV, blood nitrite/nitrate, endothelin-1 (ET-1), homeostasis model assessment for insulin resistance (HOMA-IR), and body composition were measured before and after the exercise intervention. BP (∆-7.3 ± 2.67 mmHg), baPWV (∆-1.23 ± 0.49 m/s), ET-1 (∆-14.35 ± 1.76 μmol/mL), nitrite/nitrate (∆0.5 ± 0.09 μM), HOMA-IR (∆-1.4 ± 0.07), percent body fat (∆-1.35 ± 0.9%), and waist circumference were significantly improved (P \u3c 0.05) in the EX group after 12 weeks of training versus the CON group. These findings indicate that 12 weeks of CRAE improves BP, HOMA-IR, and arterial stiffness and reduces central adiposity in obese adolescent girls with prehypertension. Thus, this study provides evidence that CRAE can be a useful therapeutic treatment for high BP, IR, and central adiposity, thereby reducing the likelihood of pathological development for cardiovascular diseases in later adulthood