OBJECTIVES/GOALS: We designed the Biocascade Exhaled Breath Sampler (BEBS) to characterize viral aerosol shedding among individuals with influenza and other respiratory virus infections. We first aimed to test the BEBS on volunteer COVID-19 cases and report the aerodynamic size distribution of exhaled breath aerosol particles carrying SARS-CoV-2 RNA. METHODS/STUDY POPULATION: From June 15 through December 15, 2022, we recruited 27 PCR-confirmed COVID-19 cases from a college campus and the surrounding community to provide 30-minute breath samples into a well-validated Gesundheit-II (G-II) exhaled breath aerosol sampler. Among these individuals, 17 provided an additional exhaled breath sample into the newly designed BEBS. We quantified samples for viral RNA using reverse transcription digital polymerase chain reaction (RT-dPCR) and determined the viral RNA copies collected within two aerosol size fractions (≤5 µm and >5 µm in diameter) from the G-II, and four aerosol size fractions (<1.15 µm, 1.15–3.2 µm, 3.3–8.2 µm, and >8.2 µm) from the BEBS. RESULTS/ANTICIPATED RESULTS: Individuals with a SARS-CoV-2 Omicron BA.4 or BA.5 infection shed virus in aerosols at an average rate of 7.5x103 RNA copies per 30-minute G-II sample, with 78% of the total RNA in aerosols ≤5 µm in diameter. Among the BEBS samples, 10% of the total viral RNA was detected in aerosols <1.15 µm, 43% in 1.15–3.2 µm, 37% in 3.3–8.2 µm, and 10% in the >8.2 µm size fraction. Based on viral RNA loads, our results indicate that exhaled aerosols ≤3.2 µm contribute the majority of SARS-CoV-2 inhalation exposure. DISCUSSION/SIGNIFICANCE: Our data provide additional evidence that respirable aerosols contribute to the spread of SARS-CoV-2. Thus, our data suggest that mitigation measures designed to reduce infectious aerosol inhalation, such as ventilation and the use of air cleaners and respirators, are needed to control the spread.

Everybody in life wants to win. At its most basic, this must stem from the survival instinct: in a battle against predators, winning means survival; defeat means death. In a social context, however, obviously not everyone can win, and we have to learn to accommodate defeat, whether our own or that of others. Hence, in a competitive society, defeat presents a challenge. Usually, if an observer sympathizes with the defeated, there is an impulse to dress up the defeat in various guises; or, if the defeated party is scorned, the defeat is presented in the most humiliating terms possible. In a gladiatorial context, the attitudes of the observer, not to mention the gladiators themselves, are hard to recover. Recent work has focused on the ‘affective dispositions’ of the spectators, drawing analogies with modern combat sports. Yet, modern spectators do not have to decide whether the defeated party deserves to live or die, whereas, for a Roman spectator, defeat was to be calibrated on a scale of life and death. The ancient protagonists themselves will obviously share impulses with their modern equivalents, although, when the contest is potentially fatal, the drive to win must take on an urgency surpassing pure ambition. When a modern athlete dies on the sports field or in the boxing ring, it is an accident, however tragic, whereas a gladiator who lost a fight could suffer the penalty of losing his life as well. Defeat was in deadly earnest.

The dynamic evolution and interaction of defects under the conditions of shock loading in nanocrystalline Al with an average grain size of 20 nm is investigated using molecular dynamics simulations for an impact velocity of 1 km/s. Four stages of defect evolution are identified during shock deformation and failure that correspond to the initial shock compression (I), the propagation of the compression wave (II), the propagation and interaction of the reflected tensile waves (III), and the nucleation, growth, and coalescence of voids (IV). The results suggest that the spall strength of the nanocrystalline Al system is attributed to a high density of Shockley partials and a slightly lower density of twinning partials (twins) in the material experiencing the peak tensile pressures.

In recent years, the government, advocacy organizations, the press, and the public have pressured universities, academic medical centers, and physicianinvestigators to do more to ensure that their financial interests and relationships do not conflict with their duties to conduct high-quality research and protect the safety and welfare of clinical trial participants. A number of factors underlie the increased focus. First, private sector funding of clinical research has grown both in absolute terms and as a proportion of overall funding. In 2008, the pharmaceutical, medical device, and biotechnology industries’ domestic research and development expenditures constituted approximately 60.9% of funding for biomedical research in the United States; the next largest funder, the National Institutes of Health, funded 27.9%. Private industry spent $58.6 billion on research in 2007, up from $40 billion in 2003, an increase of 25% after adjusting for inflation.