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In this study, a complex network method was employed to quantify the changing role of countries in fish trade and the dynamic characteristics of fish globalization. Based on the United Nations Comtrade Database, the International Trade Network for Fish and Fish Products (ITN-Fish) was constructed as a series of weighted-directed networks for each year from 1990 to 2018. Almost all countries and territories worldwide have participated in the fish trade. In 2018, the network identified 229 fish traders. The share of developing countries in imports and exports has increased. Traders actively establish new trade relations, which improve network connectivity. However, these relations only account for a small part of the fish trade. The high connectivity allows risks to spread rapidly in the world through hubs such as the United States and China, which raises concerns about the robustness of these weak links in the Sino-US trade conflict and the outbreak of COVID-19. However, we have optimistic expectations on this issue. The dynamic of network topology property shows that the globalization of fish trade flourished between 1990 and 2018. Although, due to the financial crisis and its subsequent impact, the total amount of fish trade declined in 2009 and 2015, the network structure was not seriously affected, and the trend of topology property remained unchanged. Based on the construction of the international trade network, its node attribute, and its structural attribute, fish trade maintains the trend of globalization. Countries should actively adhere to trade globalization to promote the development of the fish trade.
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Digital polymerase chain reaction (PCR), as a nucleic acid detection technology with wide application prospect, has become one of the most accurate nucleic acid detection technology at present. Multiplex detection is an important direction for the development of digital PCR technique. With the development of microfluidic technology, multiplex digital PCR technique has become more and more mature. This paper reviewed the research progresses of multiplex digital PCR in recent years, especially summarized the implementation of multiplex digital PCR technique in the past five years, and introduced the application of multiplex digital PCR technique in hot areas such as liquid biopsy, transgenic detection, and SARS-Cov-2 detection. Finally, the issues and challenges faced by multiplex digital PCR technique were discussed and the future direction of the technology was foreseen.
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This article investigates how the COVID-19 pandemic affected home and host countries' FDI margins. Heckman estimation of monthly bilateral FDI data indicates the following: (1) The pandemic reduced both the FDI margins. (2) COVID-19 mortality in home countries reduced extensive FDI margin. (3) FDI was more sensitive to host countries' pandemic situation for both OECD and emerging countries;moreover, in emerging countries, FDI was affected by its domestic pandemic control because they were typically the host countries. (4) The service sector's FDI was severely affected by the pandemic than other sectors' FDI.
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Purpose: The rates of emotional distress have risen in many countries during the COVID-19 pandemic. This study assessed the emotional distress of adolescents and young adults in Hong Kong and mainland China in the first year of the pandemic and tested whether spirituality was a protective factor against this emotional distress. Design/methodology/approach: Cross-sectional data were collected in two samples of students aged 17–25 in Hong Kong (N = 503) and 13–20 in mainland China (N = 649). Participants completed the Spiritual Health and Life Orientation Measure (SHALOM) to evaluate their spiritual health (personal-communal, environmental and transcendental domains) and the short form of the Depression, Anxiety and Stress Scale-21 (DASS-21) to assess their emotional distress. Findings: Based on the DASS-21 scores, there was a high rate of adolescents and young adults categorized as showing extremely severe symptoms of depression, anxiety and stress in both Hong Kong and mainland China. Structural equation modeling showed that in both the Hong Kong and mainland China samples the personal and communal and environmental domains of spiritual health were significantly and negatively correlated with all three forms of emotional distress. However, transcendental spiritual health was uncorrelated with psychological distress in Hong Kong and positively correlated with psychological distress in mainland China. Research limitations/implications: The high rate of severe emotional distress in this sample of adolescents and young adults under COVID-19, and the fact that not all aspects of spiritual health protected again psychological distress are cause for concern, with implications for government, education systems and students. Originality/value: Healthy spirituality can be found among youths who are upbeat, self-confident, optimistic and constructive and have also been shown to have a higher quality of life in the form of mental, physical and psychological health. The present study is the first study to examine the spiritual and mental health of high school and university students under the impact of COVID-19 in mainland China and in Hong Kong. © 2021, Emerald Publishing Limited.
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Quaternary ammonium compounds (QACs) are a class of cationic surfactants routinely used for the disinfection of industries, institutions and households, and have seen a sharp increase in use during the COVID-19 pandemic. However, current commercial QACs consist of only stable chemical bonds such as C-N, C-C, and C-H, which makes their natural degradation rather difficult. Recent studies suggest that emerging negative environmental impacts, such as systemic antibiotics resistance and toxicity to living organisms, are directly associated with prolonged exposure to QACs. Here we report a new class of QAC which contains relatively volatile chemical functional groups such as ester and thioether bonds. Degradation kinetics in aqueous solutions suggests that the stability of these QACs depends not only on their intrinsic hydrophobicity but also on external environmental factors such as pH, temperature and ion presence. The microbicidal effects of QACs containing carbon chains with various lengths were also tested, one of which, named "Ephemora", is highly active against a broad spectrum of microbes including fungi, bacteria and viruses, for instance, methicillin-resistant Staphylococcus aureus (MRSA). The easy synthesis and purification of Ephemora starting from inexpensive commercially available reagents, together with its excellent antimicrobial activity and ability to degrade in natural waters over time, make its large-scale commercial production possible.
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Objective: To monitor the changes in specific IgM and IgG antibodies in patients diagnosed with COVID-19 after SARS-CoV-2 infection, and analyze their clinical significance. Methods: A total of 168 serum samples were collected from 56 COVID-19 patients with different disease courses who were positive for nucleic acid test at Henan Center for Disease Control and Prevention on January 8, 2020 and February 21, 2020. Serum samples from 25 healthy people excluded from COVID-19 were used as control group. IgM and IgG antibodies against SARS-CoV-2 were detected by chemiluminescence method. Results: IgM antibody increased sharply in 1-3 weeks after onset, and reached the peak value (21.78 AU/ml) in the 3rd week after onset. IgG antibody increased the most in 3-6 weeks after onset, and reached the peak value (81.58 AU/ml) in the 9th week after onset. The levels of IgM and IgG antibodies were closely correlated with age and disease course (P<0.05). The antibody level of 30-60 years old group was the highest, the IgM antibody positive rate and antibody level of acute stage and previous infection were lower than that of recovery stage, and the IgG antibody positive rate and antibody level of acute stage were lower than that of recovery stage and previous infection. During the whole course of the disease, the levels of IgM and IgG antibodies increased gradually in the acute stage, reached the peak in the recovery stage, and decreased and maintained at a certain level in the past infection. Conclusions: Serum SARS-CoV-2 IgM and IgG antibody detection can be used as auxiliary diagnostic indicators for COVID-19, and its continuous observation is helpful for epidemiological investigation, serological diagnosis and disease course monitoring.
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Objective: To rapidly evaluate the level of healthcare resource demand for laboratory testing and prevention and control of corona virus disease 2019 (COVID-19) in different epidemic situation, and prepare for the capacity planning, stockpile distribution, and funding raising for infectious disease epidemic response. Methods: An susceptible, exposed, infectious, removed infectious disease dynamics model with confirmed asymptomatic infection cases and symptomatic hospitalized patients was introduced to simulate different COVID-19 epidemic situation and predict the numbers of hospitalized or isolated patients, and based on the current COVID-19 prevention and control measures in China, the demands of resources for laboratory testing and prevention and control of COVID-19 were evaluated. Results: When community or local transmission or outbreaks occur and total population nucleic acid testing is implemented, the need for human resources is 3.3-89.1 times higher than the reserved, and the current resources of medical personal protective equipment and instruments can meet the need. The surge in asymptomatic infections can also increase the human resource demand for laboratory testing and pose challenge to the prevention and control of the disease. When vaccine protection coverage reach ≥50%, appropriate adjustment of the prevention and control measures can reduce the need for laboratory and human resources. Conclusions: There is a great need in our country to reserve the human resources for laboratory testing and disease prevention and control for the response of the possible epidemic of COVID-19. Challenges to human resources resulted from total population nucleic acid testing and its necessity need to be considered. Conducting non-pharmaceutical interventions and encouraging more people to be vaccinated can mitigate the shock on healthcare resource demand in COVID-19 prevention and control.
Subject(s)
COVID-19 , Pandemics , Humans , Pandemics/prevention & control , Personal Protective Equipment , SARS-CoV-2ABSTRACT
During the novel coronavirus (COVID-19) lock down from 31st January to 2nd February, a regional atmospheric PM2.5 pollution episode had arosed concerns of society in Guangxi. Based on Nanning as an sampling site, Monitor for Aerosols and Gases in Ambient Air (MARGA), particulate LiDAR, surface meteorological and environmental data, satellite remote sensing data and modeled HYSPLIT4 trajectory were used to analyze the cause of PM2.5 pollution. According to the air quality sub-index, the observation durations were classified as the superior period, the fine period and the polluted period. The results indicated that K+ and Cl- concentrations closely related to biomass burning (BB) increased significantly during the polluted period. The average concentrations of K+ and Cl- in polluted period were 3.6 and 17.0 times higher than those corresponding figures of the superior period. The total concentration of eight water-soluble ions accounted for about 30% of PM2.5 in all three periods. The total concentration of three secondary water-soluble ions accounted for 83.33%~89.18% of the total concentration of eight ions. The high proportion of secondary inorganic components was related to the secondary transformation promoted by BB. The variation trends of proportion and levels of secondary water-soluble ions were not consistent, which was not only attributed to the emission characteristics of straw combustion, but also related to the formation mechanism and main influencing factors of different secondary inorganic ions. Straw burning spots were centralized around Nanning city during the fine period. The accumulation of direct emissions of particulate and gaseous pollutants caused by open burning of straw during the fine period under decreased boundary layer height, increased humidity and low wind speed were the main causes for atmospheric PM2.5 pollution in Nanning. During the polluted period, there was no obvious vertical transmission process of particulate matter in Nanning. The near ground was mainly affected by the southward airflow from the Beibu Gulf of Guangxi and Guangdong coastal, which indicated the regional pollution transmissions were insignificant. © 2021, Science Press. All right reserved.
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This paper analyzes the market supply and demand of polyethylene from 2015 to 2019 in China. In 2019, the production capacity of polyethylene reached 19.27 Mt, the output was 15.76 Mt, the import volume was 16.67 Mt, and the consumption volume reached 32.14 Mt. China's new polyethylene production capacity is summarized and consumption is predicted from 2020 to 2024. The forecast results show that affected by COVID-19 at the beginning of 2020, China's polyethylene consumption will be about 32.39 Mt. However, with the orderly recovery of China's economy and the growth of national industrial support, polyethylene consumption will continue to grow rapidly in the future, and it is expected to reach 37.90 Mt by 2024. Although polyethylene market is large, local enterprises in China still face severe challenges such as product homogeneity, low-priced imported products, stricter environmental protection supervision, and plastic bans. In order to survive in the fiercely competitive market, Chinese enterprises must reduce product costs, develop customized services based on user needs, carry out more scientific research and development, and strengthen independent innovation. © 2021, Beijing Yanshan Branch, Assets Management Corporation, SINOPEC. All right reserved.
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Due to the impact of COVID-19, people’s demand for non-contact tourism is increasing. The development of Internet technologies such as the Internet of Things, virtual reality (VR), and augmented reality (AR) can meet this demand. Internet technology makes non-contact tourism grow. However, these new technologies are emerging only within application cases, which cannot provide comprehensive methodological guidance for tourism suppliers. Despite the booming development of winter tourism in China, there are still many problems, especially affecting the tourist experience.rarchy process (AHP) and activity, setting, experience and benefit (ASEB) grid analysis were used to analyze the activities, settings, experiences and benefits of the scenic spot from the tourist perspective taking the Dagu Glacier Scenic Spot (DGSS) as an example. The research aims to increase the attraction of the scenic zone, and promote the coordinated and sustainable development of business in West China under the goal of improving tourists’ experiences. The results show that: subgoals of experience (E) and benefit (B) are the main directions of the development of ice and snow tourism in the DGSS. Furthermore, the threat of benefits (TB), the threat of setting (TS), the threat of experience (TE), the opportunities of benefits (OB), the opportunities of setting (OS), and the opportunities of experience (OE) are the main concerns. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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The new coronavirus can spread through respiratory droplets, and wearing a mask correctly can effectively prevent the virus from spreading. However, the current detection algorithms are based on unobstructed faces, which affects the detection task when wearing a mask. To solve these problems, a facial feature detection algorithm based on Mtcnn+Mobilenet+GDBT in complex scenes is proposed. First, it can detect whether to wear a mask and the fatigue state of the face. Second, it can set different thresholds according to the facial characteristics of different people, and initialize the characteristics of different frames in 5 seconds. The innovation of our paper: the self-adaption characteristics for every person, it avoids measuring everyone by one standard, which is of great significance to the popularization of the product. Then train a dataset of masks and feature points containing 708 images. The experimental results show that compared with the traditional detection network, the new network can effectively detect facial features in the context of the epidemic. The loss we adopt is Focal loss. The lowest loss of net is 0.01 nearly. The feature of this paper is that before the outbreak of the new crown epidemic, the relevant model only designed the detection method of whether or not to wear the mask. On the basis of wearing the mask on the face, there is no research on the algorithm for judging the facial movements such as fatigue and drowsiness. This work adopts a two-step method, using the mature face detection network mtcnn, first detects the face, and then sends it into the mobilenet network for classification and monitoring status. This makes the model parameters smaller and the accuracy higher. Even if it is divided into two steps, the lightweight network of mobilenet can run smoothly on terminal devices, especially mobile devices. As for the fatigue detection system, the extraction of fatigue features with occlusions on the face has not been circulated on the network. Therefore, our team's innovation in fatigue detection based on facial occlusions such as masks has realized more dimensional detection, with stronger robustness and smaller limitations. In the future, it can be used in areas with severe influenza virus, factories, and sterile environments. It will be able to make judgments on the mask wearing conditions of on-site personnel through real-time images collected by the camera and remind people to wear masks correctly. During the epidemic, it is equipped with an on-board video system, which automatically records the driver's facial state. If fatigue performance such as frequent blinking is detected, the monitoring system will immediately issue an alarm to ensure safety. © 2021 ACM.
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The contagion of the new coronavirus pneumonia (COVID-19) not only seriously endangers the safety of human, but also affects the development of the national economy. There are few reports on factors influencing the transmission of 2019-nCoV, such as environmental conditions (humidity and temperature), air pollution, and human activities. It is difficult to sample and research 2019-nCoV directly. Therefore, it is significant to investigate the factors influencing the spread and survival of other similar viruses, which is instructional for the prevention of epidemics and the control of 2019-nCoV transmission. The results show that: (1) Low temperature and low humidity could prolong the lifetime and increase the transmission of coronavirus, especially on dry surfaces. For example, coronavirus can survive on a smooth surface at a temperature of 22-25 ℃ and a relative humidity (RH) of 40%-45% for more than 5 days. (2) Similarly, the survival rates of the aerosolized coronavirus is also high in a closed environment at low temperature and low humidity, 2019-nCoV may hold high survival rates at a temperature of 20-25 ℃ and a relative humidity of 30%-50%. (3) The higher the particle concentration, the risk of 2019-nCoV transmission may increase. (4) The behavior of infected people also plays a important role in the transmission of 2019-nCoV. The transmission of virus can be reduced by avoiding sneezing and coughing in the crowd, and blocking the transmission of droplets using hands, elbows or other objects. Considering the above analysis, some suggestions for the prevention and control the epidemics are made, such as improving the indoor microenvironment, investigating the detection, inactivation, influence factors and propagation characteristics of 2019-nCoV. © 2020, Editorial Board, Research of Environmental Sciences. All right reserved.
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Objective: To explore the mechanism of Jingfang Granule in treatment of corona virus infection through biological information technology based on network pharmacology and molecular docking. Methods: The databases of TCMIP and TCMSP were used to summarize the flavor and meridian tropism and active compounds of Jingfang Granule, and the potential targets of active compounds were searched by PubChem and SwissTargetPrediction. The corona virus targets were collected from the GeneCards database. And common targets were enriched and analyzed by DAVID database after the intersection of the compounds targets and the disease targets. Then the network of "TCM-Ingredients-Common targets" was established by Cytoscape 3.7.2, the main active components and key targets were screened for molecular docking. Results: Totally 139 active components of Jingfang Granule and 27 common targets were obtained. GO enrichment analysis and KEGG enrichment analysis found that the pathways in cancer, MAPK signaling pathway, PI3K-Akt signaling pathway, TNF signaling pathway were the main pathways of Jingfang Granule in treatment of corona virus infection. The network of "TCM-Ingredients-Common targets" was successfully constructed, and results of molecular docking showed that the main components in this network such as β-sitosterol, cerevisterol, isorhamnetin, hesperetin, and luteolin etc., have good affinity with key targets of VEGFA, IL6, TNF, PPARγ, APP, ACE2, and SARS-CoV-2 3CL hydrolase. Conclusion: Jingfang Granule treats corona virus infectious diseases through the compatibility of multiple traditional Chinese medicine. Its resistance to corona virus infection may be through the β-sitosterol, cerevisterol, isorhamnetin, hesperetin, and luteolin act on the VEGFA, IL6, TNF, PPARγ, APP and other targets, and then affects the pathways in cancer, MAPK signal pathway, PI3K-Akt signal pathway, TNF signal pathways to achieve.