ABSTRACT
Objective: To explore the association between acute stress response during the outbreak of COVID-19 and peer bullying behaviors during the normalized management of COVID-19 among middle school students, and to provide a basis for developing relevant measures for peer bullying prevention.
ABSTRACT
The SARS-CoV virus spreads in the atmosphere mainly in the form of aerosols. Particle air filters are widely used in indoor heating, ventilation, and air-conditioning (HVAC) systems and filtration equipment to reduce aerosol concentration and improve indoor air quality. Requirements arise to rate filters according to their mass-based filtration efficiency. The size distribution of test aerosol greatly affects the measurement results of mass-based filtration efficiency and dust loading of filters, as well as the calibration of optical instruments for fine-particle (PM2.5) mass concentration measurement. The main objective of this study was to find a new method to generate a chemically nontoxic aerosol with a similar particle size distribution to atmospheric aerosol. We measured the size distribution of aerosols generated by DEHS (di-ethyl-hexyl-sebacate), PSL (poly-styrene latex), olive oil, and 20% sucrose solution with a collision nebulizer in a wide range of 15 nm–20 μm. Individually, none of the solutions generated particles that share a similar size distribution to atmospheric aerosol. We found that the 20% sucrose solution + olive oil mixture solution (Vss:Voo = 1:2) could be used to generate a chemically nontoxic aerosol with similar particle number/volume size distribution to the atmospheric aerosol (t-test, p < 0.05). The differences in the mass-base filtration efficiency measured by the generated aerosol and the atmospheric aerosol were smaller than 2% for MERV 7, 10, 13, and 16 rated filters. The aerosol generated by the new method also performed well in the calibration of optical-principle-based PM2.5 concentration measurement instruments. The average relative difference measured by a tapered element oscillating microbalance (TEOM) and a Dusttrak Model 8530 (calibrated by aerosol generated by the new method) was smaller than 5.8% in the real-situation measurement.
ABSTRACT
Background Since December 2019, there has be an outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Wuhan, China. Nowadays, it rapidly spread across the country and then the worldwide. We aimed to investigate the clinical characteristics of patients with COVID-19.Methods The patients with confirmed COVID-19 admitted between January 25 and February 10, 2020, were enrolled. Epidemiological, demographic, clinical, laboratory, radiological data, and antivirus therapies, were retrospectively collected and analyzed. The 90-day follow-up of these patients was also performed.Results A total of 107 patients were included. The median age was 55.0 years (range from 18.0 to 85.0 years), and 72 (67.3%) were female. Ninety-three (86.9%) of the patients had a history of contacting with residents from Wuhan (n=31), or contacting with confirmed COVID-19 patients (n=62) within 2 weeks. Fifty-eight (54.2%) had a family cluster onset. Fever and cough were the most common symptoms. Only two patients had diarrhea. The most common underlying disease was hypertension. Lymphopenia was observed in 26 patients. Fifty-two patients with an elevated level of IL-6. On admission, bilateral patchy shadowing and ground-glass opacity were the typical radiological findings on chest computed tomography. Six patients had an intensive care unit (ICU) stay. Antivirus therapy was performed to all patients. 105 patients discharged with an improved condition, and no death was occurred during our 90-day follow-up for these patients.Conclusions Patients with COVID-19 in our hospital had relatively mild symptoms, and good prognosis. This study also highlights the importance of human-to-human transmission in COVID-19.