Porous Semi‐Interpenetrating Hydrogel Networks Based on Dextran and Polyacrylamide With Superfast Responsiveness

AAm was free‐radical polymerized at various temperatures in the presence of N,N'‐methylenebisacrylamide as a cross‐linker and dextran resulting in novel Dx/PAAm semi‐IPNs. The structure and morphology of networks were investigated by means of FTIR, DSC, and ESEM. In comparison to the PAAm network, the interior network structures of the novel semi‐IPNs prepared at ?18 °C exhibit a heterogeneous morphology consisting of pores of sizes about 80 µm, while those formed at +5 and +25 °C have pores with sizes about 3 µm. The Dx/PAAm semi‐IPNs exhibited higher swelling ratios, than those without Dx, irrespective of the gel preparation temperature. Moreover, Dx/PAAm semi‐IPN hydrogels formed at ?18 °C attain the equilibrium state in water within 15 s.

     

Clinical correlations and pulmonary function at 8 years of age after severe neonatal respiratory failure

OBJECTIVES: The aim of this study was to determine the pulmonary sequelae of severe neonatal respiratory failure. STUDY DESIGN: This was a multicenter, prospective study. Fifty-four survivors of neonatal respiratory failure (oxygenation indices >25 on two occasions), completed pulmonary function testing at 8 years of age. Thirty-one (57%) received extracorporeal membrane oxygenation (ECMO). Pulmonary outcome was based on spirometry and lung volume data. Pulmonary outcome for each diagnostic and treatment group is reported as mean and as percent predicted. Individually subjects were also classified based on spirometry, as either normal, obstructed (defined as forced expiratory volume (FEV(1)) in 1 sec:forced vital capacity (FVC) of <80 % predicted, or with reduced FVC (FCV of <80% predicted) with normal FEV(1)/FVC. Risk for adverse outcome was determined using univariate analysis. RESULTS: Mean FVC, FEV(1) and FEV(25-75) were reduced in the total cohort. The reduction was greatest in the subgroup with CDH and the group treated with ECMO. Assessed individually, 54% of subjects had normal spirometry and lung volumes, 19% airflow obstruction, and 27% reduced FVC. Poorer pulmonary outcome was linked to ECMO, congenital diaphragmatic hernia (CDH), birth weight for gestational age <10th percentile, duration of hospitalization, or need for prolonged supplemental oxygen. CONCLUSION: Neonates with severe respiratory failure due to CDH or needing ECMO and small for gestation are at increased risk of poorer pulmonary outcome and require close follow-up.     

Non-redundant odor coding by sister mitral cells revealed by light addressable glomeruli in the mouse

Sensory inputs frequently converge on the brain in a spatially organized manner, often with overlapping inputs to multiple target neurons. Whether the responses of target neurons with common inputs become decorrelated depends on the contribution of local circuit interactions. We addressed this issue in the olfactory system using newly generated transgenic mice that express channelrhodopsin-2 in all of the olfactory sensory neurons. By selectively stimulating individual glomeruli with light, we identified mitral/tufted cells that receive common input (sister cells). Sister cells had highly correlated responses to odors, as measured by average spike rates, but their spike timing in relation to respiration was differentially altered. In contrast, non-sister cells correlated poorly on both of these measures. We suggest that sister mitral/tufted cells carry two different channels of information: average activity representing shared glomerular input and phase-specific information that refines odor representations and is substantially independent for sister cells.