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We demonstrate room-temperature 13C hyperpolarization by dynamic nuclear polarization (DNP) using optically polarized triplet electron spins in two polycrystalline systems: pentacene-doped [carboxyl-13C] benzoic acid and microdiamonds containing nitrogen-vacancy (NV−) centers. For both samples, the integrated solid effect (ISE) is used to polarize the 13C spin system in magnetic fields of 350–400 mT. In the benzoic acid sample, the 13C spin polarization is enhanced by up to 0.12 % through direct electron-to-13C polarization transfer without performing dynamic 1H polarization followed by 1H−13C cross-polarization. In addition, the ISE has been successfully applied to polarize naturally abundant 13C spins in a microdiamond sample to 0.01 %. To characterize the buildup of the 13C polarization, we discuss the efficiencies of direct polarization transfer between the electron and 13C spins as well as that of 13C−13C spin diffusion, examining various parameters which are beneficial or detrimental for successful bulk dynamic 13C polarization.

A 13‐month‐old female Toy Poodle was presented for progressive ataxia and intention tremors of head movement. The diagnosis of Sandhoff's disease (GM2 gangliosidosis) was confirmed by deficient β‐N‐acetylhexosaminidase A and B activity in circulating leukocytes and identification of the homozygous mutation (HEXB: c.283delG). White matter in the cerebrum and cerebellum was hyperintense on T2‐weighted and fluid‐attenuated inversion recovery magnetic resonance images. Over the next 2 years, the white matter lesions expanded, and bilateral lesions appeared in the cerebellum and thalamus, associated with clinical deterioration. Magnetic resonance spectroscopy showed progressive decrease in brain N‐acetylaspartate, and glycine‐myo‐inositol and lactate‐alanine were increased in the terminal clinical stage. The concentrations of myelin basic protein and neuron specific enolase in cerebrospinal fluid were persistently increased. Imaging and spectroscopic appearance correlated with histopathological findings of severe myelin loss in cerebral and cerebellar white matter and destruction of the majority of cerebral and cerebellar neurons.

A 68-year-old man with a clinical diagnosis of Alzheimer’s disease (AD) later developed amyotrophic lateral sclerosis (ALS), which was confirmed at autopsy at age 72 years. Because neuronal loss and AD-type pathologies (Braak stage II for neurofibrillary tangles) were scant, TDP-43-positive intracytoplasmic inclusions in hippocampal dentate granular cells and in neurons in the subiculum and amygdala, even though small in amount, may represent the earliest lesions of ALS-related dementia and could be the cause of dementia in this patient. Although the persistent elevation of creatine kinase from the onset could be a pointer to the presence of motor involvement, more accurate characterization of dementia, which may differentiate ALS-related dementia and AD, is necessary.

Cholic acid, deoxycholic acid, chenodeoxycholic acid, and ursodeoxycholic acid were purified by a foam fractionation method. Using thermogravimetric analysis, the attached water molecule was found to be completely removed from solids of the latter three at 100 degrees C, while cholic acid still had one water molecule of crystallization per two cholic acid molecules at that temperature. The acidity constants of the acids were accurately determined from aqueous solubility measurements at different pH values and at 15, 25, 35, and 45 degrees C. The enthalpy change of dissolution from temperature dependence of solubility as undissociated acid monomer was much less than those of common ionic surfactants. This results from a smaller entropy increase on dissolution due to the hardly flexible hydrophobic structure of these bile acids.