Oxygen Evolution Reaction at Carbon Edge Sites: Investigation of Activity Evolution and Structure–Function Relationships with Polycyclic Aromatic Hydrocarbons

The abundance of available surface chemical information and edge structures of carbon materials have attracted tremendous interest in catalysis. For the oxygen evolution reaction (OER), the edge effects of carbon materials have rarely been studied in detail because of the complexity of various coexisting edge configurations and the controversy between carbon corrosion and carbon catalysis. Herein, the exact roles of common carbon active edge sites in the OER were interrogated using polycyclic aromatic hydrocarbons (PAHs) with designated configurations (zigzag and armchair) as model probe molecules, with a focus on structure–function relationships. Zigzag configurations of PAHs showed high activity for the OER while also showing a good stability at a reasonable potential. They show a TOF value of 0.276 s^?1 in 0.1 m KOH. The catalytic activity of carbon edge sites was further effectively regulated by extending the π conjugation structure at a molecular level.     

Spinor Relativity

Spinor relativity is a unified field theory, which derives gravitational and electromagnetic fields as well as a spinor field from the geometry of an eight-dimensional complex and ‘chiral’ manifold. The structure of the theory is analogous to that of general relativity: it is based on a metric with invariance group GL(ℂ²), which combines the Lorentz group with electromagnetic U(1), and the dynamics is determined by an action, which is an integral of a curvature scalar and does not contain coupling constants. The theory is related to physics on spacetime by the assumption of a symmetry-breaking ground state such that a four-dimensional submanifold with classical properties arises. In the vicinity of the ground state, the scale of which is of Planck order, the equation system of spinor relativity reduces to the usual Einstein and Maxwell equations describing gravitational and electromagnetic fields coupled to a Dirac spinor field, which satisfies a non-linear equation; an additional equation relates the electromagnetic field to the polarization of the ground state condensate.     

Targeted mutagenesis of the Sap47 gene of Drosophila: Flies lacking the synapse associated protein of 47 kDa are viable and fertile

Background  

Conserved proteins preferentially expressed in synaptic terminals of the nervous system are likely to play a significant role in brain function. We have previously identified and molecularly characterized the Sap47 gene which codes for a novel synapse associated protein of 47 kDa in Drosophila. Sequence comparison identifies homologous proteins in numerous species including C. elegans, fish, mouse and human. First hints as to the function of this novel protein family can be obtained by generating mutants for the Sap47 gene in Drosophila.     

The nexus between alternatives assessment and green chemistry: supporting the development and adoption of safer chemicals

ABSTRACT

Alternatives assessment and green chemistry share a common goal of supporting the transition to safer, more sustainable chemicals, materials, and products. Yet the two fields, and their respective scientific communities, are not well integrated. To better understand the nexus between alternatives assessment and green chemistry as complementary approaches to support the development and adoption of safer, more sustainable chemicals for specific functional uses, this article discusses the foundations of the two fields and examines two case examples in which companies have utilized the tools and approaches of both disciplines in developing safer chemical solutions. This research demonstrates the importance and utility of the overlapping skillsets and tools of the two disciplines and the potential benefit of educational opportunities and collaborative spaces in jointly strengthening both fields. Additionally, the literature and case examples identify a number of research and practice needs that would bolster the application of both alternatives assessment and green chemistry in supporting the transition to safer, more sustainable chemistry, including: clearer definitions and criteria of what is ‘safer’; improved approaches to evaluate potential unintended consequences of chemical applications; and more effective tools to evaluate toxicity, consider inherent exposure trade-offs, and combine multiple attributes to make an informed decision.     

Gas chromatography-olfactometry analysis of the volatile compounds of two commercial Irish beef meats

The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas chromatography-olfactometry was performed by a group of eight assessors using the detection frequency methodology. The odours of the detected compounds were described as well. Eighty-one volatile compounds were identified, 11 compounds of which possessed odour activity in the first beef sample and 14 of which in the second meat sample. Ten volatile flavour compounds were common to both: methanethiol, dimethyl sulphide, 2-butanone, ethyl acetate, 2- and 3-methylbutanal, an unknown compound, 2-octanone, decanal and benzothiazole. Two unknown compounds were only detected in the first sample while 2,3-pentanedione, 4-methyl-3-penten-2-one, 2-heptanone, dimethyl trisulphide and nonanal were only perceived in the second beef. Significant differences in terms of detection frequency, odour characteristics and in nature of the volatile flavour compounds were emphasised between the two samples.