Weak Polyampholytes at the Interface of Magnetic Nanocarriers: A Facile Catch-and-Release Platform for Dyes.

We present a platform of charge-invertible core-shell hybrid particles for the selective and reversible adsorption of small charged molecules as model systems. The herein employed carrier systems consist of an iron oxide core coated with different pH-responsive polyampholytes which exhibit varying surface charge depending on the surrounding pH value. The resulting materials were used for electrostatically mediated catch-and-release experiments of either cationic or anionic dyes with the perspective to allow the pH-dependent magnetically guided transport of suitable cargo. The use of three different polyampholyte coatings (poly(2-(imidazol-1-yl)acrylic acid) (PImAA), poly(dehydroalanine) (PDha), and poly(N,N-diallylglutamate) (PDAGA)) enables a deeper understanding about how the surface net charge in combination with the charge and charge density of any cargo influences such processes. The size, surface charge, and aggregation behavior of the herein described particles were investigated via dynamic light scattering (DLS), transmission electron microscopy (TEM), and pH-dependent ζ-potential measurements, whereas adsorption and release studies were investigated via UV-vis.

Evaluation of Parameterized Convective Transport of Trace Gases in Simulation of Storms Observed During the DC3 Field Campaign.

Deep convective transport of surface moisture and pollution from the planetary boundary layer to the upper troposphere and lower stratosphere affects the radiation budget and climate. This study uses cloud-parameterized Weather Research and Forecasting model coupled with Chemistry simulations to analyze the subgrid deep convective transport of CO at 12- and 36-km horizontal resolution in supercell and mesoscale convective systems observed during the 2012 Deep Convective Clouds and Chemistry field campaign and compares the simulation results with aircraft measurements and cloud-resolved simulations. The best Weather Research and Forecasting simulation of these storms was obtained with the use of the Grell-Freitas convective scheme. The default Weather Research and Forecasting model coupled with Chemistry subgrid convective transport scheme was replaced with a scheme to compute convective transport within the Grell-Freitas subgrid cumulus parameterization, which resulted in improved transport simulations. We examined the CO tendencies due to subgrid- and grid-scale convective transport. Results showed that the subgrid convective transport started earlier than the grid-scale convective transport. The subgrid-scale convective transport reached its maximum during the hour prior to the formation of the grid-scale constant-altitude detrainment layer. After that, both the subgrid- and grid-scale convective transport began to decrease. The subgrid-scale convective transport played a more significant role in the supercell case than the mesoscale convective system case. Subgrid contribution reached ~90% at the beginning of the storm and decreased to ~30% (17%) for the 36-km (12-km) domain 4 hr later.

Using observations and source specific model tracers to characterize pollutant transport during FRAPPÉ and DISCOVER-AQ.

Transport is a key parameter in air quality research and plays a dominant role in the Colorado Northern Front Range Metropolitan Area (NFRMA), where terrain induced flows and recirculation patterns can lead to vigorous mixing of different emission sources. To assess different transport processes and their connection to air quality in the NFRMA during the FRAPPÉ and DISCOVER-AQ campaigns in summer 2014, we use the Weather Research and Forecasting Model with inert tracers. Overall, the model represents well the measured winds and the inert tracers are in good agreement with observations of comparable trace gas concentrations. The model tracers support the analysis of surface wind and ozone measurements and allow for the analysis of transport patterns and interactions of emissions. A main focus of this study is on characterizing pollution transport from the NFRMA to the mountains by mountain-valley flows and the potential for recirculating pollution back into the NFRMA. One such event on 12 August 2014 was well captured by the aircraft and is studied in more detail. The model represents the flow conditions and demonstrates that during upslope events, frequently there is a separation of air masses that are heavily influenced by oil and gas emissions to the North and dominated by urban emissions to the South. This case study provides evidence that NFRMA pollution not only can impact the nearby Foothills and mountain areas to the East of the Continental Divide, but that pollution can "spill over" into the valleys to the West of the Continental Divide.

Inhibition of dibenzo[a,l]pyrene-induced multi-organ carcinogenesis by dietary chlorophyllin in rainbow trout.

Cancer chemoprevention by dietary chlorophyllin (CHL) was investigated in a rainbow trout multi-organ tumor model. In study 1, duplicate groups of 130 juvenile trout were treated for 2 weeks with control diet, 500 p.p.m. dibenzo[a,l]pyrene (DB[a,l]P) or 500 p.p.m. DB[a,l]P + 2052 p.p.m. CHL, then returned to control diet. DB[a,l]P alone proved somewhat toxic but induced high tumor incidences in liver (61%), stomach (91%) and swimbladder (53%) 11 months after initiation. CHL co-feeding abrogated DB[a,l]P acute toxicity and reduced tumor incidences to 18% in liver, 34% in stomach and 3% in swimbladder (P