Close-Range Fire Inflicting Behind Armor Blunt Trauma: Case-Series and Implications for Battlefield Care.

Behind armor blunt trauma (BABT) is a non-penetrating injury caused by energy transfer and rapid deformation of protective body armor. Although modern military body armor is designed to prevent penetrating trunk injuries, high-energy projectiles can produce a significant energy transfer to tissues behind the armor and inflict injuries such as fractures or organ contusions. However, knowledge of BABT is limited to biomechanical and cadaver modeling studies and rare case reports. We report two cases of BABT resulting from close-range fire and discuss the potential implications for triaging patients with BABT in battlefield scenarios. In the first case, a 19-year-old male soldier sustained a single close-range 5.56-mm assault rifle gunshot to his chest body armor. The soldier initially reported mild pain in the parasternal region and assessment revealed a 4 cm × 3 cm skin abrasion. Following emergency department evaluation, the soldier was diagnosed with a non-displaced transverse fracture of the sternal body. In the second case, a 20-year-old male sustained five machine gun bullets (7.62 mm) to his body armor. Computed tomography of the chest revealed pulmonary contusions in the right lower and middle lobes. Both soldiers achieved full recovery and returned to combat duty within several weeks. These cases highlight the potential risks of energy transfer from high-velocity projectiles impacting body armor and the need for frontline providers to be aware of the risk of underlying blunt injuries. Further reporting of clinical cases and modeling studies using high-velocity projectiles could inform recommendations for triaging, evacuating, and assessing individuals with BABT.

Ocular involvement in coronavirus disease 2019 (COVID-19): a clinical and molecular analysis.

PURPOSE: Coronavirus disease 2019 (COVID-19) caused a global pandemic with millions infected worldwide. Little is known on the ocular involvement associated with the disease. The aim of this study was to assess the clinical and molecular ocular involvement among patients with confirmed COVID-19 admitted to a tertiary care facility. METHODS: Consecutive patients admitted to the COVID-19 Ward of the Shamir Medical Center in Israel during March and April, 2020 were included. The control group included patients negative for COVID-19 admitted during a similar period to a different ward. Patients were examined by trained Ophthalmologists. SARS-CoV-2 conjunctival swab samples were obtained. RESULTS: Included were 48 patients, 16 with confirmed COVID-19 and 32 controls. Median patient age was 68.5 (interquartile range: 31.5, mean: 63 ± 21) years and 48% were male. Active conjunctival injection was present in three patients (19%) with COVID-19, compared to none in the controls (p = 0.034). Patients with COVID-19 were more likely to complain of foreign body sensation (31.3% vs 3.1%, p = 0.005) and redness of the eye (25% vs 0%, p = 0.003). Conjunctival injection was associated with loss of smell and taste (75% vs 7.7%, p = 0.018). Viral conjunctival swab tests all showed negative results for all three viral genes tested (E, N, and RdRp). CONCLUSIONS: Among patients admitted to a tertiary referral center with confirmed COVID-19, active conjunctival injection was noted in one out of five cases, and was associated with loss of smell and taste. Conjunctival swabs for viral RNA were negative in patients with and without ocular involvement.

Direct observation of a sub-Poissonian number distribution of atoms in an optical lattice.

We report single-site resolution in a lattice with tunneling between sites, allowing for an in situ study of stochastic losses. The ratio of the loss rate to the tunneling rate is seen to determine the number fluctuations, and the overall profile of the lattice. Sub-Poissonian number fluctuations are observed. Deriving the lattice beams from a microlens array results in perfect relative stability between beams.

Realization of a sonic black hole analog in a Bose-Einstein condensate.

We have created an analog of a black hole in a Bose-Einstein condensate. In this sonic black hole, sound waves, rather than light waves, cannot escape the event horizon. A steplike potential accelerates the flow of the condensate to velocities which cross and exceed the speed of sound by an order of magnitude. The Landau critical velocity is therefore surpassed. The point where the flow velocity equals the speed of sound is the sonic event horizon. The effective gravity is determined from the profiles of the velocity and speed of sound. A simulation finds negative energy excitations, by means of Bragg spectroscopy.