Anatomy of an American football game: Player-to-player contact before, during and after an NFL game in context of the 2020 COVID-19 pandemic.

OBJECTIVES: To quantify levels of potential exposure to SARS-CoV-2 surrounding a typical professional American football game, with a focus on interactions on-field between teammates and opposing players before, during, and immediately after competition. METHODS: We examined across-Club consecutive interactions ≥2 minutes within 6 feet [1.8 meters] between athletes on opposing Clubs for all 2020 NFL regular season games (n = 256). Cumulative interaction was measured for a representative subset (n = 119; 46%) of games. Wearable proximity tracking devices (Kinexon) were used to measure distance and duration of interactions; these data were combined with game schedule and Club rosters for analyses. Frequency and per-game mean, median, interquartile range for consecutive interactions ≥2/≥5 minutes and cumulative interactions ≥5/≥15 were described overall and stratified by pre-game, in-game, and post-game. RESULTS: Of the 1964 distinct player-to-opponent contacts ≥2 minutes in NFL regular season games, the majority (n = 1,699; 87%) were fewer than 5 minutes in consecutive length. Among the mean 7.7 distinct contacts ≥2 minutes with opponents each game (median = 4; IQR = 2, 8), very few were ≥5 consecutive minutes at any point (mean = 1.0; median = 0; IQR = 0, 0). Most (n = 849; 43.2%) distinct contacts were pre-game, 546 (27.8%) were during competition, and 569 (29%) were post-game. In games where cumulative interactions were analyzed, there was an average of 17.1 player/opponent interactions with cumulative exposure ≥5 minutes (median = 12; IQR = 4, 30), almost all of which occurred during competition. CONCLUSION: There is limited and short contact between and among competing players in professional American football. In the setting of infectious disease such as the COVID-19 pandemic, a robust prevention program integrating masking, distancing, hygiene, and ventilation when off-field can be created to minimize on- and off-field exposures, which effectively reduces transmission risk in outdoors and/or well-ventilated stadium settings.

Positron Annihilation Study of RPV Steels Radiation Loaded by Hydrogen Ion Implantation.

Specimens of 15Kh2MFAA steel used for reactor pressure vessels V-213 (VVER-440 reactor) were studied by positron annihilation techniques in terms of their radiation resistance and structural recovery after thermal treatment. The radiation load was simulated by experimental implantation of 500 keV H+ ions. The maximum radiation damage of 1 DPA was obtained across a region of 3 µm. Radiation-induced defects were investigated by coincidence Doppler broadening spectroscopy and positron lifetime spectroscopy using a conventional positron source as well as a slow positron beam. All techniques registered an accumulation of small open-volume defects (mostly mono- and di-vacancies) due to the irradiation, with an increase of the defect volume ΔVD ≈ 2.88 × 10-8 cm-3. Finally, the irradiated specimens were gradually annealed at temperatures from 200 to 550 °C and analyzed in detail. The best defect recovery was found at a temperature between 450 and 475 °C, but the final defect concentration of about ΔCD = 0.34 ppm was still higher than in the as-received specimens.

MODELING AND OPTIMIZATION OF HPGE DETECTOR GC0518 USING MCNP5 CODE.

For precise modeling of a high purity germanium (HPGe) detector, detailed knowledge of its geometry is necessary. Unfortunately, some of the detector geometric parameters are often not available. This study suggests simple procedures for determining geometry without the need for radiography. The study considers the HPGe detector GC0518 manufactured by Mirion. The detector datasheet is available, but the uncertainties do not allow the detector to be modeled without additional corrections. The detector was modeled using MCNP5 code and the results were compared with calibration point sources and Marinelli beakers measurements. We also performed measurements to obtain information on the germanium dead layer, crystal holder shape, inner hole shape and radii of the crystal edges. Then the model was optimized according to the measurements. Finally, the full energy peak efficiencies were evaluated. The relative differences between the measured and calculated efficiencies are less than 4.5% for point sources and 5.4% for Marinelli beakers.

An unusual foreign body aspiration requiring an unusual retrieval technique.

Foreign body aspiration during medical procedures has been reported in the literature. These iatrogenic incidents could be related to instruments malfunction or to accidental occurrences during medical treatment. In this paper, we present a report of a woman coming for a laparoscopic abdominal hysterectomy who developed intraoperative bronchospasm. In an attempt to administer aerosolized albuterol, the resident anesthesia provider fractured the Luer-lock tip of the 60-cc syringe, which he was using to hold the albuterol nebulizer. The plastic tip was dislodged into the endotracheal tube (ETT). On further inspection with a fiberoptic instrument the plastic tip was located loosely adherent to the distal part of the ETT and was held in place by the moisture, which had precipitated in the distal tube. An intraoperative consult with interventional pulmonary medicine was obtained after unsuccessfully attempting to retrieve the foreign body with a grasper. The syringe tip was then removed using a Fogarty balloon catheter that was threaded through the hole of the plastic tip.

Management of a Parturient with Mast Cell Activation Syndrome: An Anesthesiologist's Experience.

Mast cell activation syndrome (MCAS) is a disorder in which patients experience symptoms and signs attributable to inappropriate mast cell activation and mediator release. Multiorgan involvement in patients can result in significant morbidity and possible mortality. Limited literature exists regarding anesthetic management of patients with MCAS. We report a case of vaginal delivery with neuraxial labor analgesia in a parturient with this condition and highlight the importance of multidisciplinary planning for uneventful outcomes. Stress can trigger life-threatening symptoms, and counseling is important to allay patients' fears. Optimum medical control, adequate premedication, avoidance of triggers, and preparedness to treat serious mediator effects are key. We review MCAS and discuss anesthetic considerations for patients with this mast cell disorder.

Transthoracic Arteriovenous Graft Repair With the Pectoralis (PECS) II Nerve Block for Primary Intraoperative Anesthesia and Postoperative Analgesia: A Case Report.

The PECS II nerve block is a relatively new regional anesthetic technique that targets the medial and lateral pectoral nerves, as well as the lateral cutaneous branches of the intercostal nerves. It has been described for surgical cases involving the breast, as an adjunct or alternative to neuraxial or paravertebral techniques. This case report describes the first successful use of the PECS II nerve block placed using ultrasound guidance as the primary anesthetic and postoperative analgesic in a non-breast-related chest wall surgery.