Association of Network Connectivity via Resting State Functional MRI with Consciousness, Mortality, and Outcomes in Neonatal Acute Brain Injury

Background An accurate and comprehensive test of integrated brain network function is needed for neonates during the acute brain injury period to inform on morbidity. This retrospective cohort study aimed to assess whether integrated brain network function by resting state functional MRI, acquired during the acute period in neonates with brain injury, is associated with acute exam, neonatal mortality, and 5-month outcomes. Methods This study included 40 consecutive neonates with resting state functional MRI acquired 1-22 days after suspected brain insult from March 2018 to July 2019 at Phoenix Childrens Hospital. Acute period exam and test results were assigned ordinal scores based on severity as documented by respective treating specialists. Analyses (Fisher exact, Wilcoxon-rank sum test, ordinal/multinomial logistic regression) examined association of resting state networks with demographics, presentation, neurological exam, electroencephalogram, anatomical MRI, magnetic resonance spectroscopy, passive task functional MRI, and outcomes of discharge condition, outpatient development, motor tone, seizure, and mortality. Results Subjects had a mean (standard deviation) gestational age of 37.8 (2.6) weeks, a majority were male (63%), with diagnosis of hypoxic ischemic encephalopathy (68%). Other findings at birth included mild distress (48%), moderately abnormal neurological exam (33%), and consciousness characterized as awake but irritable (40%). Significant associations after multiple testing corrections were detected for resting state networks: basal ganglia with outpatient developmental delay (odds ratio [OR], 14.5; 99.4% confidence interval [CI], 2.00-105; P<.001) and motor tone/weakness (OR, 9.98; 99.4% CI, 1.72-57.9; P<.001); language/frontal-parietal network with discharge condition (OR, 5.13; 99.4% CI, 1.22-21.5; P=.002) and outpatient developmental delay (OR, 4.77; 99.4% CI, 1.21-18.7; P=.002); default mode network with discharge condition (OR, 3.72; 99.4% CI, 1.01-13.78; P=.006) and neurological exam (P=.002 (FE); OR, 11.8; 99.4% CI, 0.73-191; P=.01 (OLR)); seizure onset zone with motor tone/weakness (OR, 3.31; 99.4% CI, 1.08-10.1; P=.003). Resting state networks were not detected in only three neonates, who died prior to discharge. Conclusions This study provides level 3 evidence (OCEBM Levels of Evidence Working Group) that the degree of abnormality of resting state networks in neonatal acute brain injury is associated with acute exam and outcomes. Total lack of brain network detection was only found in patients who did not survive.

Upstream extension of a bottom-advected plume and its mechanism: The case of the Yellow River

Hydrographic surveys have revealed that the Yellow River plume propagates in the direction opposite to that of a Kelvin wave (upstream) under a low river discharge condition, but turns downstream as the river discharge increases. A numerical model reproduced the upstream extension of the plume under the low river discharge condition and the transition to the downstream direction under the high river discharge condition, and confirmed that the summer wind is not the necessary condition for upstream extension of the plume. With the condition of low river discharge, the model also indicated the dependence of the upstream extension of the plume on the tidal range: extending upstream in spring tide but turning downstream in neap tide. The upstream movement of the plume results from the upstream transport of freshwater that depends on the upstream tide-induced residual current around the river mouth and the downstream density-driven current around the offshore plume front. With the condition of high river discharge, the upstream tide-induced residual current cannot compete with the downstream density-driven current and the plume turns downstream. Momentum analysis confirms the important roles of advection term and viscosity term in the condition of low river discharge and the shift to a Coriolis force-dominated system under high river discharge condition. An idealized model study suggests a dimensionless number for the river discharge changing the river plume extension from upstream to downstream under a specific upstream ambient current around the river mouth.

The Impact of Under-triage on Trauma Outcomes in Older Populations ≥65 Years

Background Undertriage of older trauma patients is implicated as a cause for outcome disparities. Undertriage is defined by an Injury Severity Score (ISS) ≥16 without full trauma activation. We hypothesized that in patients ≥65 years, undertriage is associated with unfavorable discharge. Methods This is a retrospective study of patients ≥65 years admitted at a Level 1 Trauma Center between July 2016 and June 2018 with blunt trauma. The Matrix method was used to determine the undertriage rate, and outcomes were compared between undertriaged and fully activated patients with ISS ≥16. Favorable outcomes in undertriaged patients instigated further analyses to determine factors that predicted unfavorable discharge condition, defined by discharge from the hospital with severe disability, persistent vegetative state, and in-hospital death. Results The undertriage rate was 7.9%. When compared to fully activated patients with ISS ≥16, a lower percentage of undertriaged patients were discharged in an unfavorable condition (16.6% vs 64.7%, P < .001). On the multivariate analysis, male sex (OR = 1.52), preexisting coronary artery disease (OR = 1.86), age >90 years (OR = 2.31), ISS 16-25 (OR = 3.50), Glasgow Coma Score (GCS) ≤14 (OR = 6.34), and ISS >25 (OR = 9.64) were significant independent risk factors for unfavorable discharge. Discussion The undertriage rate in patients ≥65 years was higher than the accepted standard (5%). However, undertriaged patients had better outcomes than those fully activated with ISS ≥16. Factors more predictive of unfavorable discharge condition were GCS ≤14 and ISS >25. These data suggest that ISS alone is a poor marker for assessing undertriage in older patients. Additional parameters established in this study should be considered as potential markers for better predicting outcomes in older trauma patients.

Heat Transfer of Impinging Jet-Row Onto Trapezoidal Channel With Different Effusion and Discharge Conditions

The heat transfer performances of the trapezoidal channel with the impinging row jets normal to the channel apex wall with no effusion and three effusion conditions from one, two and three rows of bleeding holes along the channel apex, or, and, channel sidewalls were studied. At each effusion condition, the airflow extraction from the channel tip were regulated as full open conditions, and 0% (full close), 5%, 10% of the total airflow rate fed into the trapezoidal channel via the impinging row jets. For each effusion and discharge condition, the full-field heat transfer data over the channel apex and sidewalls were measured at channel Reynolds numbers of 5000, 7500, 10000, 12500 and 15000 using the steady-state infrared thermography method. The corresponding axial distributions of the jet mass flow rate at each effusion and discharge condition were measured at all the Reynolds numbers tested. While the crossflow and channel flow confinement significantly affected the axial distribution of the jet flow rate for the channel without effusion, the impact of effusion and discharge conditions on the distribution of the airflow rate through the row jet was negligible for the effusion channels. Without effusion, the strong crossflow effects acted with the weakened jet momentums near the sealed channel hub to substantially reduce the regional heat transfer rates. With effusion, the flow confinement formulated by the cavity-like channel hub and the crossflow developed along the test channel were significantly suppressed, leading to the even distribution of jet flow and the recovered impinging-jet heat transfer properties over the channel hub region. The preferential heat transfer performances among the present test channels with and without effusion gave rise to the channel with three rows of effusion holes. Relative to the heat transfer impacts caused by varying the row number of the effusion holes, the impacts of tip extraction were less evident; but the overall heat transfer performance was improved by reducing tip discharge. With leading-edge cooling applications to a gas turbine blade, three sets of heat transfer correlations that evaluated the regionally averaged Nusselt numbers over the channel apex and side walls with and without effusions at various tip extractions were devised.

Transient Thermal Analysis of a Li-Ion Battery Module for Electric Cars Based on Various Cooling Fan Arrangements

This paper presents a three-dimensional modeling approach to simulate the thermal performance of a Li-ion battery module for a new urban car. A single-battery cell and a 52.3 Ah Li-ion battery module were considered, and a Newman, Tiedemann, Gu, and Kim (NTGK) model was adopted for the electrochemical modeling based on input parameters from the discharge experiment. A thermal–electrochemical coupled method was established to provide insight into the temperature variations over time under various discharge conditions. The distribution temperature of a single-battery cell was predicted accurately. Additionally, in a 5C discharge condition without a cooling system, the temperature of the battery module reached 114 °C, and the temperature difference increased to 25 °C under a 5C discharging condition. This condition led to the activation of thermal runaway and the possibility of an explosion. However, the application of a reasonable fan circulation and position reduced the maximum temperature to 49.7 °C under the 5C discharge condition. Moreover, accurate prediction of the temperature difference between cell areas during operation allowed for a clear understanding and design of an appropriate fan system.