1-methyl-(D3)-trishomocubane

The acid catalysed rearrangement of 8-methyl-pentacyclo(5.4.0.0^2,6.0^3,10.0^5,9)undecan-8-endo-o1 ($\text{8}$) to 3-methyl-(D₃)-trishomocuban-4-o1 ($\text{9}$) provided the key step to the synthesis of the title compound ($\text{11}$).     

Implications of the Rician distribution for fMRI generalized likelihood ratio tests

In functional magnetic resonance imaging (fMRI), the general linear model test (GLMT) is widely used for brain activation detection. However, the GLMT relies on the assumption that the noise corrupting the data is Gaussian distributed. Because the majority of fMRI studies employ magnitude image reconstructions, which are Rician distributed, this assumption is invalid and has significant consequences in case the signal-to-noise ratio (SNR) is low. In this study, we show that the GLMT should not be used at low SNR. Furthermore, we propose a generalized likelihood ratio test for magnitude MR data that has the same performance compared to the GLMT for high SNR, but performs significantly better than the GLMT for low SNR.     

Streaming currents in a single nanofluidic channel

We report measurements of the streaming current, an electrical current generated by a pressure-driven liquid flow, in individual rectangular silica nanochannels down to 70 nm in height. The streaming current is observed to be proportional to the pressure gradient and increases with the channel height. As a function of salt concentration, it is approximately constant below approximately 10 mM, whereas it strongly decreases at higher salt. Changing the sign of the surface charge is found to reverse the streaming current. The data are best modeled using a nonlinear Poisson-Boltzmann theory that includes the salt-dependent hydration state of the silica surface.     

Structure of a 1:1 complex between the anthelmintic drug mebendazole and propionic acid

Recrystallization of the anthelmintic drug mebendazole from propionic acid yields a 1:1 molecular complex which crystallizes in the triclinic system space group , a = 5.928(2), b = 11.066(2), c = 14.337(6)Å, = 94.89(3), = 101.56(3), = 96.18(2)°, and Z = 2 complex units in the unit cell. An x-ray diffraction study revealed an R ₂ ² (8) hydrogen bonding system in the complex, involving the unprotonated imidazole N and amide N–H function of the drug and the acid carboxylic group. Complex molecules form centrosymmetric dimers by intermolecular N–H···O hydrogen bonding involving the protonated imidazole N atom and the benzoyl O atom of the drug molecule.