Development of the Density Modified Displacement (DMD) method for efficient recovery of DNAPLS from contaminated aquifers: experimental evaluation and mathematical modeling

Issued as final reportTrac II: Subproject I

Surfactant enhanced remediation of soil columns contaminated by residual tetrachloroethylene

The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting 14C-labeled PCE into water-saturated soil columns and displacing the free product with water. Miscible displacement experiments were conducted before and after PCE entrapment to determine the influence of residual PCE on column dispersivities. The first two column studies involved the injection of a 4% solution of polyoxyethylene (POE) (20) sorbitan monooleate, resulting in the removal of 90% and 97% of the residual PCE from 20-30- and 40-120-mesh Ottawa sand, respectively. Although micellar solubilization of PCE was the primary mode of recovery in these experiments, this process was shown to be rate-limited based on: (a) the disparity between initial steady-state concentrations of PCE in the column effluent and equilibrium values measured in batch experiments; and (b) the increase in effluent concentrations of PCE following periods of flow interruption. In the latter two experiments, surfactant solutions containing mixtures of sodium sulfosuccinates removed >99% of the residual PCE from soil columns packed with 40-270-mesh Ottawa sand. Approximately 80% of the PCE was mobilized as a separate organic liquid after lushing with -1) are not required to achieve significant PCE mobilization when buoyancy forces are important. The potential for displacement of dense nonaqueousphase liquids as a separate organic phase should, therefore, be evaluated during the selection of surfactant formulations for aquifer remediation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31591/1/0000520.pd

25-Hydroxyvitamin D Depletion Does Not Exacerbate MPTP-Induced Dopamine Neuron Damage in Mice

Recent clinical evidence supports a link between 25-hydroxyvitamin D insufficiency (serum 25-hydroxyvitamin D [25(OH)D] levels <30 ng/mL) and Parkinson’s disease. To investigate the effect of 25(OH)D depletion on neuronal susceptibility to toxic insult, we induced a state of 25(OH)D deficiency in mice and then challenged them with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We found there was no significant difference between control and 25(OH)D-deficient animals in striatal dopamine levels or dopamine transporter and tyrosine hydroxylase expression after lesioning with MPTP. Additionally, we found no difference in tyrosine hydroxylase expression in the substantia nigra pars compacta. Our data suggest that reducing 25(OH)D serum levels in mice has no effect on the vulnerability of nigral dopaminergic neurons in vivo in this model system of parkinsonism

Uncharted waters: rare and unclassified cardiomyopathies characterized on cardiac magnetic resonance imaging

Cardiac magnetic resonance imaging (CMR) has undergone considerable technology advances in recent years, so that it is now entering into mainstream cardiac imaging practice. In particular, CMR is proving to be a valuable imaging tool in the detection, morphological assessment and functional assessment of cardiomyopathies. Although our understanding of this broad group of heart disorders continues to expand, it is an evolving group of entities, with the rarer cardiomyopathies remaining poorly understood or even unclassified. In this review, we describe the clinical and pathophysiological aspects of several of the rare/unclassified cardiomyopathies and their appearance on CMR

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms