Optimal trade policy and welfare in a differentiated duopoly

This study considers a differentiated duopoly, including domestic and foreign enterprises, in trade, analyzes the impacts of product differentiation and productivity variance on equilibrium results, and explores the optimal trade policy in different competition modes. We find that differentiated products can boost the supply of foreign enterprises in a Cournot competition. In a home-leading Stackelberg duopoly, increasing tariffs decreases consumer surplus but improves the home country's social welfare. The optimum-welfare tariff of a home-leading Stackelberg duopoly cannot exceed that of the foreign-leading Stackelberg duopoly. An easy or tight tariff policy can be optimal, depending on the parameters and duopoly modes.

Repositioning Molecules of Chinese Medicine to Targets of SARS-Cov-2 by Deep Learning Method

Traditional Chinese medicine has been used to treat and prevent infectious diseases for thousands of years, and has accumulated a large number of effective prescriptions. Deep learning methods provide powerful applications in calculating interactions between drugs and targets. In this study, we try to use the method of deep learning to reposition molecules of Chinese medicines (CMs) and the targets of syndrome coronavirus 2 (SARS-CoV-2). A deep convolution neural network with residual module (DCNN-Res) is constructed and trained on KIBA dataset. The accuracy of predicting the binding affinity of drug-target pairs is 85.33%. By ranking binding affinity scores of 433 molecules in 35 CMs to 6 targets of SARS-Cov-2, DCNN-Res recommends 30 possible repositioning molecules. The consistency between our result and the latest research is 0.827. The molecules in Gancao and Huangqin have a strong binding affinity to targets of SARS-CoV-2, which is also consistent with the latest research.

Analysis of the disposal of medical waste management at home and abroad and suggestions on countermeasures

The widespread outbreak of COVID-19 in 2020 has aroused great concern of the government and the public on the environmental management and safe disposal of medical wastes. Developed countries have established a relatively comprehensive medical waste management system, while the China's medical waste management system and treatment methods still need to be improved. The current status of the production, management and disposal of medical wastes were analyzed systematically in this paper to summarize and analyze the problems of medical waste management and disposal in China. Learned from the foreign practices, effective methods such as strengthening the classified medical waste collection management system, the establishment of the producers responsible recycling system, the full implemention of the centralized processing system, the strengthening of the whole process of tracking management of each link, the deepening of the disposal technology research, and the building of the emergency disposal of medical wastes management system were put forward to provide references for further standardizing the development in this field. © 2020, China Environmental Science Press. All rights reserved.

STREPTOCOCCUS ANGINOSUS LUNG ABSCESS WITH CORONAVIRUS 2019 PNEUMONIA

SESSION TITLE: Medical Student/Resident Chest Infections Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: We present a case of undiagnosed lung abscess with Coronavirus 2019. CASE PRESENTATION: A 71-year-old female with history of right lower lobe (RLL) lesion (noted six years ago on chest x-ray [CXR]) and 45-pack year smoker presented to the Emergency Room for shortness of breath (SOB). She reported two months of worsening SOB, productive cough, and unintentional weight loss. Physical exam revealed RLL wheezes. Her oxygen saturation was 89% on room air. Admission labs showed leukocytosis and elevated procalcitonin (Table 1). Initial imaging demonstrated a large RLL multiloculated lung abscess (LA) (Figure 1). We initiated oxygen and intravenous (IV) broad spectrum antibiotics. Coronavirus 2019 (COVID-19) came back positive and hydroxychloroquine was started. Thoracentesis of the LA revealed Streptococcus (Strep) anginosus that was susceptible to penicillins. The patient was then switched to Amoxicillin for 4 weeks. Repeat Computed Tomography (CT) of chest after 4 weeks revealed RLL consolidation evolution with decreased parenchymal fluid loculations (Figure 2). The pulmonologist restarted Amoxicillin for 4 weeks, ordered repeat COVID-19 testing, and referred to oncology. DISCUSSION: A LA is a cavity of the pulmonary parenchyma filled with fluid caused by infection or necrotic debris. They remain a significant cause of morbidity and mortality, despite antibiotic treatment, with an incidence rate of 15-20%. [1] Our patient likely has a chronic, secondary LA as the onset was greater than 4 weeks and has an underlying lesion. They commonly develop, at an incidence rate of 26-80%, from aspiration pneumonia via oral anaerobes. Polymicrobial LA are also seen with aerobic bacteria, frequently Strep species. The Strep milleri group contains 3 different species, one of which is Strep anginosus. These bacteria are part of the oral flora, but can also cause LA. [2] Our cultures only grew Strep anginosus, which is atypical. We did not observe any acute risk factors of aspiration or immunosuppression, but the patient does have remote history of dental abscess, IV drug use, and alcoholism. The patient presented with acute COVID-19 which causes cough and mild fever, but can progress to severe dyspnea and hypoxemia. On CT, initial findings are subpleural ground glass opacities and after 2 weeks multiple, large consolidations are seen in the subpleural lower lobes. The lesion is gradually absorbed with residual findings of ground glass opacities and parenchymal bands. [3] Our patient’s CT was consistent with COVID-19 pneumonia. However, the RLL consolidation was noted on CXR from six years ago and after 4 weeks of amoxicillin from this admission, which suggests a chronic process. We believe the LA has been present and asymptomatic for years, but the patient did not present until her COVID-19 infection. CONCLUSIONS: We illustrate how LA can remain undiagnosed until exacerbated by an acute process. Reference #1: Bartlett JG. Anaerobic Bacterial Infections of the Lung. Chest. 1987;91(6):901-909. Reference #2: Mukae H, Noguchi S, Naito K, et al. The Importance of Obligate Anaerobes and the Streptococcus anginosus Group in Pulmonary Abscess: A Clone Library Analysis Using Bronchoalveolar Lavage Fluid. Respiration. 2016;92:80-89. Reference #3: Wu J, Wu X, Zeng W, et al. Chest CT Findings in Patients With Coronavirus Disease 2019 and Its Relationship With Clinical Features. Investigative Radiology. 2020;55(5):257-261. DISCLOSURES: No relevant relationships by James Choi, source=Web Response No relevant relationships by Rakesh Gami, source=Web Response No relevant relationships by Tyler Kemnic, source=Web Response No relevant relationships by Jason Liu Liu, source=Web Response No relevant relationships by Rohan Prasad, source=Web Response No relevant relationships by Fazal Raziq, source=Web Response