Development of Dissolution Dynamic Nuclear Polarization of [15 N3 ]Metronidazole: A Clinically Approved Antibiotic.

We report dissolution Dynamic Nuclear Polarization (d-DNP) of [15 N3 ]metronidazole ([15 N3 ]MNZ) for the first time. Metronidazole is a clinically approved antibiotic, which can be potentially employed as a hypoxia-sensing molecular probe using 15 N hyperpolarized (HP) nucleus. The DNP process is very efficient for [15 N3 ]MNZ with an exponential build-up constant of 13.8 min using trityl radical. After dissolution and sample transfer to a nearby 4.7 T Magnetic Resonance Imaging scanner, HP [15 N3 ]MNZ lasted remarkably long with T1 values up to 343 s and 15 N polarizations up to 6.4 %. A time series of HP [15 N3 ]MNZ images was acquired in vitro using a steady state free precession sequence on the 15 NO2 peak. The signal lasted over 13 min with notably long T2 of 20.5 s. HP [15 N3 ]MNZ was injected in the tail vein of a healthy rat, and dynamic spectroscopy was performed over the rat brain. The in vivo HP 15 N signals persisted over 70 s, demonstrating an unprecedented opportunity for in vivo studies.

Partial volume correction of PET image data using geometric transfer matrices based on uniform B-splines.

Objective. Most methods for partial volume correction (PVC) of positron emission tomography (PET) data employ anatomical segmentation of images into regions of interest. This approach is not optimal for exploratory functional imaging beyond regional hypotheses. Here, we describe a novel method for unbiased voxel-wise PVC.Approach.B-spline basis functions were combined with geometric transfer matrices to enable a method (bsGTM) that provides PVC or alternatively provides smoothing with minimal regional crosstalk. The efficacy of the proposed method was evaluated using Monte Carlo simulations, human PET data, and murine functional PET data.Main results.In simulations, bsGTM provided recovery of partial volume signal loss comparable to iterative deconvolution, while demonstrating superior resilience to noise. In a real murine PET dataset, bsGTM yielded much higher sensitivity for detecting amphetamine-induced reduction of [11C]raclopride binding potential. In human PET data, bsGTM smoothing enabled increased signal-to-noise ratios with less degradation of binding potentials relative to Gaussian convolution or non-local means.Significance.bsGTM offers improved performance for PVC relative to iterative deconvolution, the current method of choice for voxel-wise PVC, especially in the common PET regime of low signal-to-noise ratio. The new method provides an anatomically unbiased way to compensate partial volume errors in cases where anatomical segmentation is unavailable or of questionable relevance or accuracy.

Future directions in research on institutional and interpersonal discrimination and children's health.

Research evidence indicates that 2 forms of racial discrimination-perceived interpersonal discrimination and racial/ethnic residential segregation (a form of institutional discrimination)-may influence children's health and disparities. Although research on these 2 forms of discrimination and health has primarily focused on adults, smaller bodies of work have documented that perceived interpersonal discrimination and segregation have a negative effect on infants' health, and that perceived interpersonal discrimination may negatively affect children's mental health. Three directions for research are (1) incorporating a life-course perspective into studies of discrimination and children's health, (2) linking residential segregation with geography-of-opportunity conceptual frameworks and measures, and (3) considering residential segregation along with segregation in other contexts that influence children's health (e.g., schools).

Racial And Ethnic Inequities In Children's Neighborhoods: Evidence From The New Child Opportunity Index 2.0.

Neighborhoods influence children's health, so it is important to have measures of children's neighborhood environments. Using the Child Opportunity Index 2.0, a composite metric of the neighborhood conditions that children experience today across the US, we present new evidence of vast geographic and racial/ethnic inequities in neighborhood conditions in the 100 largest metropolitan areas in the US. Child Opportunity Scores range from 20 in Fresno, California, to 83 in Madison, Wisconsin. However, more than 90 percent of the variation in neighborhood opportunity happens within metropolitan areas. In 35 percent of these areas the Child Opportunity Gap (the difference between Child Opportunity Scores in very low- and very high-opportunity neighborhoods) is higher than across the entire national neighborhood distribution. Nationally, the Child Opportunity Score for White children (73) is much higher than for Black (24) and Hispanic (33) children. To improve children's health and well-being, the health sector must move beyond a focus on treating disease or modifying individual behavior to a broader focus on neighborhood conditions. This will require the health sector to both implement place-based interventions and collaborate with other sectors such as housing to execute mobility-based interventions.

The child opportunity index: improving collaboration between community development and public health.

Improving neighborhood environments for children through community development and other interventions may help improve children's health and reduce inequities in health. A first step is to develop a population-level surveillance system of children's neighborhood environments. This article presents the newly developed Child Opportunity Index for the 100 largest US metropolitan areas. The index examines the extent of racial/ethnic inequity in the distribution of children across levels of neighborhood opportunity. We found that high concentrations of black and Hispanic children in the lowest-opportunity neighborhoods are pervasive across US metropolitan areas. We also found that 40 percent of black and 32 percent of Hispanic children live in very low-opportunity neighborhoods within their metropolitan area, compared to 9 percent of white children. This inequity is greater in some metropolitan areas, especially those with high levels of residential segregation. The Child Opportunity Index provides perspectives on child opportunity at the neighborhood and regional levels and can inform place-based community development interventions and non-place-based interventions that address inequities across a region. The index can also be used to meet new community data reporting requirements under the Affordable Care Act.

Integrating racial/ethnic equity into policy assessments to improve child health.

The US child population is rapidly becoming more racially and ethnically diverse, yet there are persistent racial/ethnic gaps in child health. Improving and expanding policies to reduce these gaps is increasingly a mandate of government agencies. Identifying effective policies requires a rigorous approach, yet there is a lack of information about which policies improve equity. This article introduces the Policy Equity Assessment, a framework that combines policy assessment and rigorous equity methods to both synthesize existing research and identify and conduct new analyses of policies' ability to reduce racial/ethnic inequities. We applied the Policy Equity Assessment to three policies: Head Start, the Family and Medical Leave Act, and a federal housing assistance program known as Section 8. Our results show racial/ethnic inequities in access to benefits and substantial data and evidence gaps regarding the impact of policies in improving racial/ethnic equity. These results should motivate policy makers to strengthen equity analysis.