The crystal structure of atazanavir has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Atazanavir crystallizes in space group P21 (#4) with a = 15.33545(7), b = 5.90396(3), c = 21.56949(13) Å, β = 96.2923(4)°, V = 1941.134(11) Å3, and Z = 2. Despite being labeled as “atazanavir sulfate”, the commercial reagent sample consisted of atazanavir free base. The structure consists of an array of extended-conformation molecules parallel to the ac-plane. Although the atazanavir molecule contains only four classical hydrogen bond donors, hydrogen bonding is, surprisingly, important to the crystal energy. Both intra- and intermolecular hydrogen bonds are significant. The hydroxyl group forms bifurcated intramolecular hydrogen bonds to a carbonyl oxygen atom and an amide nitrogen. Several amide nitrogens act as donors to the hydroxyl group and carbonyl oxygen atoms. An amide nitrogen acts as a donor to another amide nitrogen. Several methyl, methylene, methyne, and phenyl hydrogens participate in hydrogen bonds to carbonyl oxygens, an amide nitrogen, and the pyridine nitrogen. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1426.

The coronavirus disease 2019 (COVID-19) outbreak in Wuhan, China, spread rapidly throughout China and gradually to some countries abroad. How is the development of an epidemic controlled? Early diagnosis is one of the important contents in prevention and control. COVID-19 patients with early mild pneumonia often lack typical evidence to make a definitive diagnosis. Based on the analysis of the cases of 4 patients, this article finds that early diagnosis requires a combination of epidemiology, clinical manifestations, imaging, and etiology, with particular emphasis on epidemiology history and chest computed tomography (CT) manifestations.

COVID-19 as an emerging disease has spread to 183 countries and territories worldwide as of 20 March 2020. The first COVID-19 case (i.e. the index case) in Iran was observed in the city of Qom on 19 February 2020. One of the cities of Markazi Province is Delijan, which shares a border with Qom. Consequently, COVID-19 has quickly spread in this city because a large population commutes daily between the two cities. This study aimed to report the challenges and considerations of community-based preparedness at the onset of COVID-19 outbreak in a city of Iran in 2020.

The outbreak of coronavirus disease 2019 (COVID-19) caused by the virus SARS-CoV-2 is expanding globally. South Korea is one of the countries most affected by COVID-19 from the very early stages of this pandemic. Explosive outbreaks occurred across South Korea in the first two months, and efforts to control this new virus have involved everyone across the country. To curb the transmission of the virus, health-care professionals, committees, and governments have combined many approaches, such as extensive COVID-19 screening, effective patient triage, the transparent provision of information, and the use of information technology. This experience could provide some valuable ideas and lessons to others who are fighting against COVID-19.

There is no patient emergency more important than protecting health care workers during a pandemic.