Chemical constituents and antimicrobial activity of Goniothalamus macrophyllus (Annonaceae) from Pasoh Forest Reserve, Malaysia

The essential oils from the twig and root of Goniothalamus macrophyllus were obtained by hydrodistillation and subjected to Gas Chromatography (GC-FID) and Gas Chromatography/Mass Spectrometry (GC-MS) using CBP-5 capillary column in order to determine their chemical composition. Both twig and root oils and four reference standard compounds (-pinene, linalool, geraniol and geranyl acetate) were evaluated for their antimicrobial properties against gram positive and gram negative bacteria, yeast and dermatophyte fungi using broth microdilution methods. The GCMS analysis revealed twenty-one and fourteen compounds from twig and root oils which represented 90.0 and 42.5% of the total oils, respectively. The oils were found to possess the following major components: twig: geranyl acetate (45.5%), geraniol (17.0%), linalool (12.7%) and camphene (7.5%); root: cyperene (9.8%), geranyl acetate (9.4%), geraniol (3.4%) and linalool (2.6%). Other components present in appreciable amounts in both essential oils were -pinene (0.8%) and benzaldehyde (0.5%). The root oil exhibited the most notable inhibitory activity (0.3 mg/ml) against Vancomycin intermediate-resistance Staphylococcus aureus (VISA 24), Staphylococcus epidermidis and Candida albicans. -pinene meanwhile inhibited the bacteria and fungal growth at 0.3 and 2.5 mg/ml. With regards to antimicrobial potential, -pinene superceeds linalool, geraniol and geranyl acetate, respectively.Keywords: Goniothalamus macrophyllus, Annonaceae, essential oils, geranyl acetate, cyperene, geraniol, linalool, -pinene, antimicrobial activityAfrican Journal of Biotechnology Vol. 9(34), pp. 5511-5515, 23 August, 201

Composition Screening of Lithium- and Sodium-Rich Anti-Perovskites for Fast-Conducting Solid Electrolytes

Li- and Na-rich anti-perovskites are receiving increasing attention as high-performance solid electrolytes for applications within all-solid-state batteries. The defect chemistry and ionic transport in a wide range of Li3–xNaxOCl1–yBry compositions are examined using advanced materials modeling techniques. Our calculations indicate that alkali-halide Schottky defect pairs are the dominant type of intrinsic disorder in these materials. Li-ion conductivity is shown to significantly exceed Na-ion conductivity, with the highest conductivities found for Li3OCl and Li3OBr. The effect of Cl/Br mixing on conductivity is shown to be small but could be used to fine-tune the activation energy. Both low conductivities and high activation energy barriers are found for the mixed Li/Na systems, which suggests that they would make poor solid electrolytes. The results presented here will aid the future optimization of anti-perovskite materials for solid electrolyte applications

Technical Education in Jeopardy? Assessing the Interdisciplinary Faculty Structure in a University Merger

The social responsibility of universities is to contribute to solving the ‘wicked problems’ facing humanity, including climate change, poverty, conflicts and the lack of energy resources. Interdisciplinarity is an approach that enables solving these problems and helps higher education institutions become more socially responsible while meeting the requirements of their stakeholders. In this chapter, we analyse a multidisciplinary and sector-breaking merger of three higher education institutions in Finland, where the merger is justified by its contribution to solving wicked problems through increased structural interdisciplinarity. We examine the suggested faculty structures and views of staff and students to understand how interdisciplinarity and addressing the needs of stakeholders are seen from the perspective of technical education. The interdisciplinary faculty structure is heavily criticised by the internal stakeholders, who claim that it does not meet the needs of the university’s external stakeholders. However, there is debate on whose interests and identities are at risk when the disciplinary boundaries of technical education are transgressed.peerReviewe

Cooperative mechanisms of fast-ion conduction in gallium-based oxides with tetrahedral moieties.

NoThe need for greater energy efficiency has garnered increasing support for the use of fuel-cell technology, a prime example being the solid-oxide fuel cell1, 2. A crucial requirement for such devices is a good ionic (O2- or H+) conductor as the electrolyte3, 4. Traditionally, fluorite- and perovskite-type oxides have been targeted3, 4, 5, 6, although there is growing interest in alternative structure types for intermediate-temperature (400¿700 °C) solid-oxide fuel cells. In particular, structures containing tetrahedral moieties, such as La1-xCaxMO4-x/2(M=Ta,Nb,P) (refs 7,8), La1-xBa1+xGaO4-x/2 (refs 9,10) and La9.33+xSi6O26+3x/2 (ref. 11), have been attracting considerable attention recently. However, an atomic-scale understanding of the conduction mechanisms in these systems is still lacking; such mechanistic detail is important for developing strategies for optimizing the conductivity, as well as identifying next-generation materials. In this context, we report a combined experimental and computational modelling study of the La1-xBa1+xGaO4-x/2 system, which exhibits both proton and oxide-ion conduction9, 10. Here we show that oxide-ion conduction proceeds via a cooperative 'cog-wheel'-type process involving the breaking and re-forming of Ga2O7 units, whereas the rate-limiting step for proton conduction is intra-tetrahedron proton transfer. Both mechanisms are unusual for ceramic oxide materials, and similar cooperative processes may be important in related systems containing tetrahedral moieties