Contribution of emissions from the oil sands activities in Alberta, Canada to atmospheric concentration and deposition of nitrogen and sulfur species at a downwind site.

Oil sands activities in the Athabasca Oil Sands Region in Alberta, Canada, are large sources of atmospheric NOx and SO2. This study investigated the impact of oil sands emissions on the atmospheric deposition of nitrogen and sulfur species at a downwind site, about 350 km from the oil sands facilities. Measurement data are from the Canadian Air and Precipitation Monitoring Network (CAPMoN) from 2015 to 2019, including ambient concentrations of HNO3, pNO3-, NO2, pNH4+, NH3, SO2, pSO42- and base cations, as well as concentrations of NO3-, SO42-, NH4+, and base cations in precipitation. Sector analysis of air mass back trajectories was conducted to distinguish measurements with different air mass origins. Median atmospheric concentrations and dry deposition fluxes of HNO3, pNO3-, NO2, pNH4+, pSO42-, and SO2 on days when the air masses came from the oil sands sector were significantly greater than those with the "Clean" sector by 34-67%, whereas the difference in NH3 concentration was not significant. Contributions of the oil sands emissions to dry deposition fluxes of these species ranged from 3.8 to 13.1%. The precipitation-weighted mean concentrations of NO3-, SO42-, and NH4+ in samples with the oil sands sector were 76 %, 65 % and 81 % greater than those with the "Clean" sector, respectively. Contributions of the oil sands emissions to wet deposition of NO3-, SO42-, and NH4+ were 12.5 ± 8.9 %, 8.7 ± 4.4 %, and 6.0 ± 3.3 %, respectively. The annual total deposition of nitrogen and sulfur were 1.9 kg-N ha-1 and 0.74 kg-S ha-1, respectively, of which 8.0 ± 3.5 % and 8.7 ± 3.6 % were from oil sands emissions. The total deposition of sulfur and nitrogen did not exceed the critical loads (CL) of acidity, but nitrogen deposition exceeded the CLs of nutrient nitrogen in the region.

What Happens on Call Doesn't Stay on Call. The Effects of In-house Call on Acute Care Surgeons' Sleep and Burnout: Results of the Surgeon Performance (SuPer) Trial.

OBJECTIVE: We sought to quantify the effects of in-house call(IHC) on sleep patterns and burnout among acute care surgeons (ACS). BACKGROUND: Many ACS take INC, which leads to disrupted sleep and high levels of stress and burnout. METHODS: Physiological and survey data of 224 ACS with IHC were collected over 6 months. Participants continuously wore a physiological tracking device and responded to daily electronic surveys. Daily surveys captured work and life events as well as feelings of restfulness and burnout. The Maslach Burnout Inventory (MBI) was administered at the beginning and end of the study period. RESULTS: Physiological data were recorded for 34,135 days, which includes 4389 nights of IHC. Feelings of moderate, very, or extreme burnout occurred 25.7% of days and feelings of being moderately, slightly, or not at all rested occurred 75.91% of days. Decreased amount of time since the last IHC, reduced sleep duration, being on call, and having a bad outcome all contribute to greater feelings of daily burnout ( P <0.001). Decreased time since last call also exacerbates the negative effect of IHC on burnout ( P <0.01). CONCLUSIONS: ACS exhibit lower quality and reduced amount of sleep compared with an age-matched population. Furthermore, reduced sleep and decreased time since the last call led to increased feelings of daily burnout, accumulating in emotional exhaustion as measured on the MBI. A reevaluation of IHC requirements and patterns as well as identification of countermeasures to restore homeostatic wellness in ACS is essential to protect and optimize our workforce.

Nanodiamonds with Surface Grafted Polymer Chains as Vehicles for Cell Imaging and Cisplatin Delivery: Enhancement of Cell Toxicity by POEGMEMA Coating.

Nanodiamonds (NDs) are highly promising drug carriers due to their biocompatibility, manipulable surface chemistry, and nonbleaching flourescence. In this communication, we compare the cytotoxicity of three ND-cisplatin systems in which cisplatin was incorporated via direct attachment to the ND surface, physical adsorption within a poly(oligo(ethylene glycol) methyl ether methacrylate) POEGMEMA surface coating, or complexation to 1,1-di-tert-butyl 3-(2-methacryloyloxy)ethyl)butane-1,1,3-tricarboxylate (MAETC) groups of a POEGMEMA-st-PMAETC surface layer. The polymer layers were introduced by grafting from RAFT-functionalized ND particles. All three ND systems displayed lower IC50 values than free cisplatin in A2870 and A2870cis ovarian cancer cells. The two polymer-containing systems outperformed their "naked" counterpart, with the POEGMEMA-coated particles the most cytotoxic, displaying an IC50 of 1.5 µM, more than an order of magnitude lower than that of cisplatin. The enhanced cytotoxicity is attributed to promotion of cellular uptake by the hydrophilic surface polymer.

Micelles based on gold-glycopolymer complexes as new chemotherapy drug delivery agents.

Polymeric versions of deacetylated auranofin, a gold complex with a sugar ligand, were prepared by post-modifying RAFT glycopolymers. Micellisation of a block copolymer containing pendant Au(I) units produced nanoparticles with an increased anti-proliferative effect against OVCAR-3 human ovarian carcinoma cells.