Hydrogen Bonds Effects on the Electrical Properties of Pectin/Pva Graphene Nanocomposites

Electrical properties were studied for Pectin/PVA graphene composites films and the effect of aqueous interaction on their properties. The conductivity and the dielectric constant of this composite are important because Polysaccharide like pectin is increasingly being used in biomedical applications and as nanoparticles coating materials. The Dielectric and conductivity of composite films were compared in dry and wet condition the differences in the results were attributed to the water molecules and the hydrogen bond which connect the three composite compounds (Pectin, PVA and Graphene) together. These connections were allowed the hydrogen and hydroxyl group’s migrations in the composite super molecules. On the other hand, graphene was prepared and with different techniques like Ft-IR, XRD, SEM and AFM characterized. Keywords: Hydrogen Bonds, nanocomposite , dielectric constant , Pectin/PVA graphene nanocomposit

Physical Properties of Pure and Nano Agdoped Liquid Crystalline Compounds Containing 1,3,4-Oxadizole Unit

Dielectric properties and other physical properties such as electrical conductivity (AC) and relaxation time or activation energy have been studied for two systems pure LC [V]6,6, [V]7,6, [V]8,6, [V]6,7, [V]7,7 and [V]8,7 and their doped with silver nanoparticles. The results show the increasing in real dielectric permittivity έ with increasing length terminal chain. So the real dielectric permittivity increasing with raising temperature. To compare between the values of at (400) Hz and (4000) Hz we observe these values at the low frequency are larger than that in high frequency. Generally, one can see that the doping of Ag nano particles effectively reduced the permittivity of the LC materials with its large electric dipole moment. The electrical conductivity value for pure LC samples in general increases  with increasing temperature. So we observed increasing of  electrical conductivity values at high frequency. The time scale is discussed in terms of the Arrhenius plot. Generally, with increasing the temperature the time period that spend by molecules at the transition state will increase. The activation energy Ea values show the increase in the activation energy to the doped systems.

Strongyloides stercoralis hyperinfection after corticosteroid therapy: a report of two cases

Two cases of Strongyloides stercoralis hyperinfection are described. Both patients were expatriates from the Indian subcontinent, and reported the use of corticosteroids. The first patient presented with severe pulmonary disease that necessitated respiratory support, followed by acute abdomen and intestinal obstruction and he succumbed to these diseases. The second patient also presented with acute pulmonary disease, which responded to antihelmintic treatment and supportive care; however, he died later due to his primary disease. The clinical features of S stercoralis hyperinfection are nonspecific; therefore, a high index of suspicion is required for early diagnosis and to start appropriate therapy. Because of the seriousness of the disease and the associated high mortality we suggest screening for S stercoralis in patients from endemic areas who will be taking immunosuppressive therapy