Impact of pre-conception health care: evaluation of a social determinants focused intervention.

The purpose of this study was to evaluate the outcomes of the social determinants component of a multiple determinants model of pre- and inter-conception care. Health department vital statistics and infectious disease data on birth and factors influencing birth outcomes were analyzed for participants in a program designed to mitigate the effects of social class and stress in contrast to a matched comparison group and other relevant populations. The program showed promising results related to reducing infant mortality and reducing other high-risk factors for poor birth outcomes, including low birth weight and sexually transmitted disease. Social determinant interventions, designed to mitigate the impact of social class and stress, should be considered with efforts to reduce infant mortality, particularly the disparities associated with infant mortality. Additional research should be conducted to refine replicable social determinant focused interventions and confirm and generalize these results.

Spin coherence transfer in chemical transformations monitored by remote detection NMR.

We demonstrate a nuclear magnetic resonance (NMR) experiment using continuous flow in a microfluidic channel for studying the transfer of spin coherence in nonequilibrium chemical processes. We use the principle of remote detection, which involves spatially separated NMR encoding and detection coils. As an example, we provide the map of chemical shift correlations for the amino acid alanine as it transitions from the zwitterionic to the anionic form. The presented method uniquely allows for tracking the migration of encoded spins during the course of any chemical transformation and can provide useful information about reaction mechanisms.

NMR velocity mapping of gas flow around solid objects.

We present experimental visualizations of gas flow around solid blunt bodies by NMR imaging. NMR velocimetry is a model-free and tracer-free experimental means for quantitative and multi-dimensional flow visualization. Hyperpolarization of (129)Xe provided sufficient NMR signal to overcome the low density of the dilute gas phase, and its long coherence time allows for true velocity vector mapping. In this study, the diverging gas flow around and wake patterns immediately behind a sphere could be vectorally visualized and quantified. In a similar experiment, the flow over an aerodynamic model airplane body revealed a less disrupted flow pattern.

NMR analysis on microfluidic devices by remote detection.

We present a novel approach to perform high-sensitivity NMR imaging and spectroscopic analysis on microfluidic devices. The application of NMR, the most information-rich spectroscopic technique, to microfluidic devices remains a challenge because the inherently low sensitivity of NMR is aggravated by small fluid volumes leading to low NMR signal and geometric constraints resulting in poor efficiency for inductive detection. We address the latter by physically separating signal detection from encoding of information with remote detection. Thereby, we use a commercial imaging probe with sufficiently large diameter to encompass the entire device, enabling encoding of NMR information at any location on the chip. Because large-diameter coils are too insensitive for detection, we store the encoded information as longitudinal magnetization and flow it into the outlet capillary. There, we detect the signal with optimal sensitivity, using a solenoidal microcoil, and reconstruct the information encoded in the fluid. We present a generally applicable design for a detection-only microcoil probe that can be inserted into the bore of a commercial imaging probe. Using hyperpolarized 129Xe gas, we show that this probe enables sensitive reconstruction of NMR spectroscopic information encoded by the large imaging probe while keeping the flexibility of a large coil.

Microfluidic gas-flow profiling using remote-detection NMR.

We have used nuclear magnetic resonance (NMR) to obtain spatially and temporally resolved profiles of gas flow in microfluidic devices. Remote detection of the NMR signal both overcomes the sensitivity limitation of NMR and enables time-of-flight measurement in addition to spatially resolved imaging. Thus, detailed insight is gained into the effects of flow, diffusion, and mixing in specific geometries. The ability for noninvasive measurement of microfluidic flow, without the introduction of foreign tracer particles, is unique to this approach and is important for the design and operation of microfluidic devices. Although here we demonstrate an application to gas flow, extension to liquids, which have higher density, is implicit.

Amplification of xenon NMR and MRI by remote detection.

A technique is proposed in which an NMR spectrum or MRI is encoded and stored as spin polarization and is then moved to a different physical location to be detected. Remote detection allows the separate optimization of the encoding and detection steps, permitting the independent choice of experimental conditions and excitation and detection methodologies. In the initial experimental demonstration of this technique, we show that taking dilute 129Xe from a porous sample placed inside a large encoding coil and concentrating it into a smaller detection coil can amplify NMR signal. In general, the study of NMR active molecules at low concentration that have low physical filling factor is facilitated by remote detection. In the second experimental demonstration, MRI information encoded in a very low-field magnet (4-7 mT) is transferred to a high-field magnet (4.2 T) to be detected under optimized conditions. Furthermore, remote detection allows the utilization of ultrasensitive optical or superconducting quantum interference device detection techniques, which broadens the horizon of NMR experimentation.

Balancing values and imperatives: a study of nursing service in an ICU.

There has been significant attention from the managers and purchasers of health services regarding the economic advantages that result from changes to the patterns of health care delivery in the acute hospital setting. The impact of these changes, whilst often rendering advantage at the economic management level of health care, can have different consequences for the people who deliver and the people who receive health service. This paper reports on a study that was conducted with a group of nurses to investigate the practice milieu of a critical care unit in the context of changes to health service management. Interpretive methods were used to capture the perspective of the nurses and the way they interpret the multiple factors that influence their practice and their practice environment. The findings indicate that the nurses in the study setting interpret these factors according to the influences they have on the structure, the geography and the value of their work. Explication of these findings provides a research base to inform recommendations relating to improving the practice milieu of the critical care environment.