Risk assessment of dietary exposure to Aflatoxin contamination in spices

This study highlights the daily consumption of spices in human diet and the potential of aflatoxin B1 (AFBI) contamination which attributable to the risk of developing liver cancer. All the AFBI contamination data in spices from various studies in Malaysia were considered for calculation of risk assessment by dietary exposure and margin of exposure (MOE). The mean dietary exposure to AFB1 ranges from 0.21-1.32 ng/kg-bw/day (overall mean, 0.59 ng/kgbw/ day), and 12.27 ng/kg-bw/day was the highest reported level of AFBI contamination. The MOEs derived from these dietary exposures at a benchmark dose lower confidence limit (BMDL10) of 0.305 μg/kg-bw/day were 230-1,450 (overall mean, 520). The MOE of less than 10,000 indicates the risk of AFBI contamination in spices should be a high priority for risk management actions. Based on the tolerable daily intake (TDI) in Asia of 0.11-0.19 ng AFB1/kg-bw/day for liver, the overall mean of 0.59 ng/kg-bw/day represents 3-536% of this TDI. Population risk for primary liver cancer attributable to AFB1 contamination in spices were 0.01-0.03 (0.1-0.7%) and 0-0.31 (0-6%) cancers/year/100,000 population, for mean and range of exposures. The risk, which was less than 1 cancer case/year/100,000 population, suggested that Malaysian population is not significantly at risk

Cd3As2 is Centrosymmetric

This is a revised version of a manuscript that was originally posted here in February of 2014. It has been accepted at the journal Inorganic Chemistry after reviews that included those of two crystallographers who made sure all the t's were crossed and the i's were dotted. The old work (from 1968) that said that Cd3As2 was noncentrosymmetric was mistaken, with the authors of that study making a type of error that in the 1980s became infamous in crystallography. As a result of the increased scrutiny of the issue of centrosymmetricity of the 1980's, there are now much better analysis tools to resolve the issue fully, and its important to understand that not just our crystals are centrosymmetric, even the old guy's crystals were centrosymmetric (and by implication everyone's are). There is no shame in having made that error back in the day and those authors would not find the current centrosymmetric result controversial; their paper is excellent in all other aspects. This manuscript describes how the structure is determined, explains the structure schematically, calculates the electronic structure based on the correct centrosymmetric crystal structure, and gives the structural details that should be used for future analysis and modeling.Comment: Accepted by ACS Inorganic Chemistr

A Non-Centrosymmetric Superconductor with a Bulk 3D Dirac Cone Gapped by Strong Spin Orbit Coupling

Layered, non-centrosymmetric, heavy element PbTaSe2 is found to be superconducting. We report its electronic properties accompanied by electronic structure calculations. Specific heat, electrical resistivity and magnetic susceptibility measurements indicate that PbTaSe2 is a moderately coupled, type-II BCS superconductor (Tc = 3.72 K, Ginzburg-Landau parameter Kappa = 14) with an electronphonon coupling constant of Lambda_ep = 0.74. Electronic structure calculations reveal a single bulk 3D Dirac cone at the K point of the Brillouin Zone derived exclusively from its hexagonal Pb layer; it is similar to the feature found in graphene except there is a 0.8 eV gap opened by spin-orbit coupling. The combination of large spin-orbit coupling and lack of inversion symmetry also results in large Rashba splitting on the order of tenths of eV

Diffusion of a Janus nanoparticle in an explicit solvent: A molecular dynamics simulation study

Molecular dynamics simulations are carried out to study the translational and rotational diffusion of a single Janus particle immersed in a dense Lennard-Jones fluid. We consider a spherical particle with two hemispheres of different wettability. The analysis of the particle dynamics is based on the time-dependent orientation tensor, particle displacement, as well as the translational and angular velocity autocorrelation functions. It was found that both translational and rotational diffusion coefficients increase with decreasing surface energy at the nonwetting hemisphere, provided that the wettability of the other hemisphere remains unchanged. We also observed that in contrast to homogeneous particles, the nonwetting hemisphere of the Janus particle tends to rotate in the direction of the displacement vector during the rotational relaxation time.Comment: Web reference added for animations:http://www.wright.edu/~nikolai.priezjev/janus/janus.htm