Rapid Acute Coronary Syndrome Evaluation Over One Hour With High-Sensitivity Cardiac Troponin I: A United States-Based Stepped-Wedge, Randomized Trial.

STUDY OBJECTIVE: The real-world effectiveness and safety of a 0/1-hour accelerated protocol using high-sensitivity cardiac troponin (hs-cTn) to exclude myocardial infarction (MI) compared to routine care in the United States is uncertain. The objective was to compare a 0/1-hour accelerated protocol for evaluation of MI to a 0/3-hour standard care protocol. METHODS: The RACE-IT trial was a stepped-wedge, randomized trial across 9 emergency departments (EDs) that enrolled 32,609 patients evaluated for possible MI from July 2020 through April 2021. Patients undergoing high-sensitivity cardiac troponin I testing with concentrations less than or equal to 99th percentile were included. Patients who had MI excluded by the 0/1-hour protocol could be discharged from the ED. Patients in the standard care protocol had 0- and 3-hour troponin testing and application of a modified HEART score to be eligible for discharge. The primary endpoint was the proportion of patients discharged from the ED without 30-day death or MI. RESULTS: There were 13,505 and 19,104 patients evaluated in the standard care and accelerated protocol groups, respectively, of whom 19,152 (58.7%) were discharged directly from the ED. There was no significant difference in safe discharges between standard care and the accelerated protocol (59.5% vs 57.8%; adjusted odds ratio (aOR)=1.05, 95% confidence interval [CI] 0.95 to 1.16). At 30 days, there were 90 deaths or MIs with 38 (0.4%) in the standard care group and 52 (0.4%) in the accelerated protocol group (aOR=0.84, 95% CI 0.43 to 1.68). CONCLUSION: A 0/1-hour accelerated protocol using high-sensitivity cardiac troponin I did not lead to more safe ED discharges compared with standard care.

Impact of the Particle Diameter on Ion Cloud Formation from Gold Nanoparticles in ICPMS.

The unique capabilities of microsecond dwell time (DT) single-particle inductively coupled plasma mass spectrometry (spICPMS) were utilized to characterize the cloud of ions generated from the introduction of suspensions of gold nanoparticles (AuNPs) into the plasma. A set of narrowly distributed particles with diameters ranging from 15.4 to 100.1 nm was synthesized and characterized according to established protocols. Statistically significant numbers of the short transient spICPMS events were evaluated by using 50 µs DT for their summed intensity, maximum intensity, and duration, of which all three were found to depend on the particle diameter. The summed intensity increases from 10 to 1661 counts and the maximum intensity from 6 to 309 counts for AuNPs with diameters from 15.4 to 83.2 nm. The event duration rises from 322 to 1007 µs upon increasing AuNP diameter. These numbers represent a comprehensive set of key data points of the ion clouds generated in ICPMS from AuNPs. The extension of event duration is of high interest to appoint the maximum possible particle number concentration at which separation of consecutive events in spICPMS can still be achieved. Moreover, the combined evaluation of all above-mentioned ion cloud characteristics can explain the regularly observed prolonged single-particle events. The transport and ionization behavior of AuNPs in the ICP was also computationally modeled to gain insight into the size-dependent signal generation. The simulated data reveals that the plasma temperature, and therefore the point of ionization of the particles, is the same for all diameters. However, the maximum number density of Au+, as well as the extent of the ion cloud, depends on the particle diameter, in agreement with the experimental data, and it provides an adequate explanation for the observed ion cloud characteristics.

Evaluation of selected solid adsorbents for passive sampling of atmospheric oil and natural gas non-methane hydrocarbons.

This project investigated passive adsorbent sampling of light (C2-C5) hydrocarbons which are sensitive tracers of fugitive emissions from oil and natural gas (O&NG) sources. Stronger adsorbent materials, i.e. Carboxen 1000 and Carboxen 1016, than those typically used in adsorbent sampling were considered. Experiments were conducted in laboratory and field settings using thermal desorption - gas chromatography analysis. Uptake of water vapor and system blanks were challenges inherent to the increased affinity of these adsorbents. Carboxen 1000 exhibited the best signal-to-noise ratio for the target compounds after optimizing conditioning parameters to reduce blanks, and by reducing the adsorbent mass loaded in the cartridge. This strategy reduced blanks to equivalent ambient air mole fractions of <0.05 nmol mol-1 (ppb), and allowed determination of these O&NG tracers over three-day sampling intervals with a lower detection limit of ≥0.5-1 ppb. Linear VOCs uptake was observed in dry air. Water uptake was as high as 0.65 gH2O g-1adsorbent at relative humidity (RH) above ≈ 75%. The water collection passivates adsorbent sites and competes with the uptake rates of VOCs; under the worst case relative humidity level of 95% RH, VOCs uptake rates dropped to 27-39% of those in dry air. This effect potentially causes results to be biased low when cartridges are deployed at high relative humidity (RH), including overnight, when RH is often elevated over daytime levels. Nonetheless, representative sampling results were obtained under ambient conditions during three field studies where cartridges were evaluated alongside whole air sample collection in canisters. Agreement varied by compound: Ethane and alkenes correlated poorly and could not be analyzed with satisfactory results; results for C3-C5 alkanes were much better: i-butane correlated with R2 > 0.5, and propane, n-butane, i-pentane, and n-pentane with R2 > 0.75, which demonstrates the feasibility of the passive sampling of these latter O&NG tracers. Implications: Oil and natural gas development has been associated with emissions of petroleum hydrocarbons that impact air quality and human health. This research characterizes and defines the application possibilities of solid adsorbent sampling for atmospheric passive sampling monitoring of low molecular weight volatile organic compounds (i.e. ethane through pentane isomers) that are most commonly emitted from natural gas drilling and well sites. The passive sampling of these pollutants offers a simple, low cost, and readily applicable monitoring method for assessing emissions and air quality impacts in the surroundings of oil and gas operations.

Spatially and size-resolved analysis of gold nanoparticles in rat spleen after intratracheal instillation by laser ablation-inductively coupled plasma-mass spectrometry.

In a dual approach, laser ablation-inductively coupled plasma-mass spectrometry was applied to investigate spleen samples of rats after intratracheal instillation of polyvinylpyrrolidone-coated gold nanoparticles. First, spatially resolved imaging analysis was deployed to investigate gold translocation from the lungs to the spleen and to investigate the distribution pattern of gold in the spleen parenchyma itself. Using the same instrumental setup, laser ablation-inductively coupled plasma-mass spectrometry in single particle mode was applied to determine the species of translocated gold. Single particle analysis allows the determination of particle size distributions and therefore to distinguish between ionic species, intact nanoparticles, and agglomerates. A translocation of instilled gold from the lungs to the spleen was demonstrated for gold nanoparticles of 30 and 50 nm diameter. Furthermore single particle analysis revealed the translocation of intact gold nanoparticles in a non-agglomerated state.