3D X-ray microtomography study on fibre breakage in noil hemp fibre reinforced polypropylene composites

X-ray microtomography, image processing and Weibull statistical methods were used to characterize the length and width distributions of noil hemp fibres before and after composite fabrication. X-ray microtomography provided direct observations and accurate measurements of length and width of noil hemp fibres within the hemp–polypropylene composite matrix. The effects of the weight content of the noil hemp fibre and the addition of compatibilizer on the fibre breakage and tensile strength of the composites were studied. The results indicated that the tensile strength of the noil hemp fibre reinforced composites without the coupling agent was lower than that of pure polypropylene. Fibre–fibre interaction mechanism indicated that high hemp content caused more fibre breakage. The addition of maleic anhydride grafted polypropylene (MAPP) coupling agent improved the tensile strength of the composites by the enhanced fibre/matrix interfacial adhesion. The addition of MAPP also reduced the fibre breakage due to the better dispersion of fibres

T-Helper Cytokine Patterns and Related Antibodies in Patients with Gestational Diabetes Mellitus

Background: Diabetes mellitus (DM) is a group of metabolic disorders such as DM I, DM II, secondary causes of DM and gestational diabetes mellitus characterized by hyperglycemic phonotype. The etiology of gestational diabetes mellitus is unknown. Recent studies address the chronic activity of immune system against infections (not autoimmunity) as an important cause of gestational diabetes mellitus. This study aimed to compare T-helper cells 1 and 2 cytokines and associated antibodies in patients with gestational diabetes mellitus and normal pregnant women. Methods: This cross-sectional study was performed on 45 female patients with GDM and 45 healthy pregnant women in Bandar Abbas, Iran, from 2008- 2009. The exclusion criteria were presence of any infectious diseases or autoimmune disorders such as SLE or RA. Present and past medical histories were taken from the participants thorough physical examination. Blood samples (10 mL) were drawn and sent to laboratory for measuring serum IgE, IgG1, IgG2, IgG3, IgG4, interleukin-10 (IL-10), interleukin-12 (IL-12), transforming growth factor-beta (TGF1), and interferon-gamma (IFN) measurements. T-test and Kolmogorov-Smirnov test were used for data analysis. Results: The mean age of the patients with GDM and healthy pregnant women was 32.5 and 27.9 yrs, respectively. T-helper 1 and 2 associated antibodies and cytokines had no significant differences between the case and control groups. Conclusion: The changes in T-helper 1 and 2 associated antibodies and cytokines are not associated with gestational diabetes mellitus and could not be considered as a predictor for gestational diabetes mellitus

T-helper cytokine patterns and related antibodies in patients with gestational diabetes mellitus

Background: Diabetes mellitus (DM) is a group of metabolic disorders such as DM I, DM II, secondary causes of DM and gestational diabetes mellitus characterized by hyperglycemic phonotype. The etiology of gestational diabetes mellitus is unknown. Recent studies address the chronic activity of immune system against infections (not autoimmunity) as an important cause of gestational diabetes mellitus. This study aimed to compare T-helper cells 1 and 2 cytokines and associated antibodies in patients with gestational diabetes mellitus and normal pregnant women. Methods: This cross-sectional study was performed on 45 female patients with GDM and 45 healthy pregnant women in Bandar Abbas, Iran, from 2008- 2009. The exclusion criteria were presence of any infectious diseases or autoimmune disorders such as SLE or RA. Present and past medical histories were taken from the participants thorough physical examination. Blood samples (10 mL) were drawn and sent to laboratory for measuring serum IgE, IgG1, IgG2, IgG3, IgG4, interleukin-10 (IL-10), interleukin-12 (IL-12), transforming growth factor-beta (TGF1), and interferon-gamma (IFN) measurements. T-test and Kolmogorov-Smirnov test were used for data analysis. Results: The mean age of the patients with GDM and healthy pregnant women was 32.5 and 27.9 yrs, respectively. T-helper 1 and 2 associated antibodies and cytokines had no significant differences between the case and control groups. Conclusion: The changes in T-helper 1 and 2 associated antibodies and cytokines are not associated with gestational diabetes mellitus and could not be considered as a predictor for gestational diabetes mellitus

Vibration damping characteristics of short hemp fibre thermoplastic composites

In this project, free vibration testing and dynamic mechanical analysis methods were used to study the damping properties of noil hemp fibre-reinforced polypropylene composites with varying fibre contents (0 to 60 wt%) and compatibilizers (maleic anhydride-grafted polypropylene and maleic anhydride-grafted polyethylene octane) under applied frequencies of 1 to 200 Hz. The storage modulus of the composites was increased by the increase in hemp fibre content. However, the maximum damping ratio was obtained from the composite with 30 wt% noil hemp fibre. The addition of coupling agents reduced the damping capacity of all composites. However, 30 wt% noil hemp fibre-reinforced polypropylene coupled with 2.5 wt% anhydride-grafted poly ethylene octane revealed the highest damping ratio among coupled composites. Damping properties of the composites were relatively constant over the frequency range, except at frequencies which the material–instrument system began to resonate and peaks were observed in the curves