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1.
Int J Environ Res Public Health ; 20(1)2022 12 26.
Article in English | MEDLINE | ID: covidwho-2268869

ABSTRACT

The aims of this study were to examine the psychometric properties of two subjective outcome evaluation tools measuring students' perceptions of 24 instructional videos and to understand the profiles of students' perceptions of the videos. Online teaching and learning played an important role when school lockdown measures were imposed during the COVID-19 pandemic. To facilitate online teaching in a college-level leadership education subject, we developed and piloted 24 instructional videos, including 15 animated videos and 9 case-based videos, in the 2021/22 academic year. To understand students' perceptions of the videos, we developed two subjective outcome evaluation scales (one for the animated videos and another for the case-based videos) to assess the subjective perceptions of 1308 students. Results showed that the developed tools possessed good psychometric properties, including factorial, convergent and discriminant validity. The findings of this study also revealed the students had positive attitudes towards the developed videos, including positive perceptions of the videos' design and the benefits gained from watching them. The present study suggests teachers can meaningfully use the 24 instructional videos in the context of leadership education in higher education.


Subject(s)
COVID-19 , Pandemics , Humans , Pandemics/prevention & control , Leadership , Communicable Disease Control , Learning
2.
Virus Res ; 328: 199075, 2023 04 15.
Article in English | MEDLINE | ID: covidwho-2255888

ABSTRACT

SARS-CoV-2, known as severe acute respiratory syndrome coronavirus 2, is causing a massive global public health dilemma. In particular, the outbreak of the Omicron variants of SARS-CoV-2 in several countries has aroused the great attention of the World Health Organization (WHO). As of February 1st, 2023, the WHO had counted 671,016,135 confirmed cases and 6,835,595 deaths worldwide. Despite effective vaccines and drug treatments, there is currently no way to completely and directly eliminate SARS-CoV-2. Moreover, frequent cases of SARS-CoV-2 infection in animals have also been reported. In this review, we suggest that SARS-CoV-2, as a zoonotic virus, may be frequently transmitted between animals and humans in the future, which provides a reference and warning for rational prevention and control of COVID-19.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Humans , Disease Outbreaks , World Health Organization
3.
Journal of computer science and technology : Duplicate, marked for deletion ; 37(6):1464-1477, 2022.
Article in English | EuropePMC | ID: covidwho-2170225

ABSTRACT

Generating molecules with desired properties is an important task in chemistry and pharmacy. An efficient method may have a positive impact on finding drugs to treat diseases like COVID-19. Data mining and artificial intelligence may be good ways to find an efficient method. Recently, both the generative models based on deep learning and the work based on genetic algorithms have made some progress in generating molecules and optimizing the molecule's properties. However, existing methods need to be improved in efficiency and performance. To solve these problems, we propose a method named the Chemical Genetic Algorithm for Large Molecular Space (CALM). Specifically, CALM employs a scalable and efficient molecular representation called molecular matrix. Then, we design corresponding crossover, mutation, and mask operators inspired by domain knowledge and previous studies. We apply our genetic algorithm to several tasks related to molecular property optimization and constraint molecular optimization. The results of these tasks show that our approach outperforms the other state-of-the-art deep learning and genetic algorithm methods, where the z tests performed on the results of several experiments show that our method is more than 99% likely to be significant. At the same time, based on the experimental results, we point out the insufficiency in the experimental evaluation standard which affects the fair evaluation of previous work. Supplementary Information The online version contains supplementary material available at 10.1007/s11390-021-0970-3.

4.
Chem Commun (Camb) ; 58(83): 11697-11700, 2022 Oct 18.
Article in English | MEDLINE | ID: covidwho-2186137

ABSTRACT

A novel composite was fabricated by hybridizing terbium 1,3,5-benzenetricarboxylic MOF (TB-MOF) with Cx[6]. The obtained composite TB-Cx[6] possessed long-term stability and dispersion stability and was used for on-site analysis of the anti-COVID-19 disinfection product Prednis via a combing remote sampling technique.


Subject(s)
Lanthanoid Series Elements , Metal-Organic Frameworks , Calixarenes , Pharmaceutical Preparations , Phenols , Terbium
5.
Cells ; 11(23)2022 Dec 05.
Article in English | MEDLINE | ID: covidwho-2199806

ABSTRACT

Crossbreeding, mutation breeding, and traditional transgenic breeding take much time to improve desirable characters/traits. CRISPR/Cas-mediated genome editing (GE) is a game-changing tool that can create variation in desired traits, such as biotic and abiotic resistance, increase quality and yield in less time with easy applications, high efficiency, and low cost in producing the targeted edits for rapid improvement of crop plants. Plant pathogens and the severe environment cause considerable crop losses worldwide. GE approaches have emerged and opened new doors for breeding multiple-resistance crop varieties. Here, we have summarized recent advances in CRISPR/Cas-mediated GE for resistance against biotic and abiotic stresses in a crop molecular breeding program that includes the modification and improvement of genes response to biotic stresses induced by fungus, virus, and bacterial pathogens. We also discussed in depth the application of CRISPR/Cas for abiotic stresses (herbicide, drought, heat, and cold) in plants. In addition, we discussed the limitations and future challenges faced by breeders using GE tools for crop improvement and suggested directions for future improvements in GE for agricultural applications, providing novel ideas to create super cultivars with broad resistance to biotic and abiotic stress.


Subject(s)
CRISPR-Cas Systems , Gene Editing , CRISPR-Cas Systems/genetics , Plants, Genetically Modified/genetics , Genome, Plant , Stress, Physiological/genetics
6.
Hum Vaccin Immunother ; 19(1): 2167436, 2023 12 31.
Article in English | MEDLINE | ID: covidwho-2187765
7.
Hum Vaccin Immunother ; : 2141519, 2022 Nov 22.
Article in English | MEDLINE | ID: covidwho-2123047

ABSTRACT

This observational retrospective study was conducted on patients with epilepsy (PWE) in China who had at least one dose of COVID-19 vaccine and it investigated the safety of vaccination by analyzing changes in epileptic seizures and their influencing factors. Consecutive PWE who were followed up in the epilepsy clinic between June 2021 and May 2022 were enrolled. Data on vaccine type, demographic information, clinical characteristics of epilepsy, and treatment were collected through a questionnaire survey and retrospectively analyzed. PWE were divided into a stable seizure group and a worsening seizure group based on seizure episodes at least 90 days after the first vaccine dose. A total of 79 PWE were included. After vaccination, 14 patients (17.7%) had worsening seizures, 92.9% of whom had an increased seizure frequency. Compared with patients in the stable seizure group, patients in the worsening seizure group had significant differences in baseline monthly seizure frequency (P = .012), improper antiseizure medication (ASM) administration (P = .003) and a disrupted sleep routine (P = .016). Multivariate logistic regression analysis showed that improper ASM administration (OR 6.186, 95% confidence interval [CI] 1.312-29.170; p = .021) and a disrupted sleep routine (OR 6.326, 95% CI 1.326-30.174; p = .021) were significantly associated with seizure worsening. In short, COVID-19 vaccination is safe for PWE, and only those with poor seizure control have the possibility of seizure exacerbation after COVID-19 vaccination. The vaccination per se does not represent a major influencing factor, but the improper use of ASMs and a disrupted sleep routine may be correlated with seizure aggravation after vaccination.

8.
Front Public Health ; 10: 1040169, 2022.
Article in English | MEDLINE | ID: covidwho-2119889

ABSTRACT

Background: During the COVID-19 pandemic, adolescents' use of social networking sites/apps has surged, and their mental health and quality of life have also been significantly affected by the pandemic and its associated social-protection measures. The present study first examined the prevalence of social networking sites/apps use and social networking addiction, the mental health status, and the health-related quality of life among Hong Kong adolescent students. We further investigated the associations of the youths' daily use of social networking sites/apps and their social networking addiction with their mental health and quality of life during the pandemic. Methods: A total of 1,147 students (age = 15.20 ± 0.53 years) recruited from 12 randomly selected local secondary schools in Hong Kong participated in a questionnaire survey in classroom settings between January and June, 2020, right after the COVID-19 outbreak. The questionnaire includes demographic characteristics and scales that measure social networking sites/apps use and social networking addiction, mental health, and quality of life. Results: Approximately 46.4% of the participants reported using social networking sites/apps often or very often, and 7.8% met the criteria for social networking addiction using Bergen's Social Media Addiction Scale. The prevalence of mild to extremely severe depression, anxiety, and stress among the adolescents stood at 39.6, 37.5, 48.8%, respectively, and the participants' physical, social, and school functioning were lower than the norms of healthy adolescents before the pandemic. Participants who used social networking sites/apps but for <3 h per day (excluding students who never used social networking sites/apps) showed significantly fewer problems of depression, anxiety, and stress than did those who spent more than 3 h per day on social networking sites/apps. Social networking addiction was found to be consistently associated with poor mental health and health-related quality of life. Conclusion: This study provides important evidence supporting the potential protective effect of guiding adolescents to use social networking sites/apps appropriately in order to mitigate their negative emotions during contexts such as that of the pandemic; it further points to the need to provide extra support to promote the well-being of young people, especially those in disadvantaged situations (e.g., non-intact family) during and after the pandemic.


Subject(s)
COVID-19 , Mental Health , Adolescent , Humans , Quality of Life , COVID-19/epidemiology , Pandemics , Hong Kong/epidemiology , Social Networking
9.
J Clin Nurs ; 2022 Sep 30.
Article in English | MEDLINE | ID: covidwho-2052769

ABSTRACT

AIMS AND OBJECTIVES: To determine the frequency, timing, and duration of post-acute sequelae of SARS-CoV-2 infection (PASC) and their impact on health and function. BACKGROUND: Post-acute sequelae of SARS-CoV-2 infection is an emerging major public health problem that is poorly understood and has no current treatment or cure. PASC is a new syndrome that has yet to be fully clinically characterised. DESIGN: Descriptive cross-sectional survey (n = 5163) was conducted from online COVID-19 survivor support groups who reported symptoms for more than 21 days following SARS-CoV-2 infection. METHODS: Participants reported background demographics and the date and method of their covid diagnosis, as well as all symptoms experienced since onset of covid in terms of the symptom start date, duration, and Likert scales measuring three symptom-specific health impacts: pain and discomfort, work impairment, and social impairment. Descriptive statistics and measures of central tendencies were computed for participant demographics and symptom data. RESULTS: Participants reported experiencing a mean of 21 symptoms (range 1-93); fatigue (79.0%), headache (55.3%), shortness of breath (55.3%) and difficulty concentrating (53.6%) were the most common. Symptoms often remitted and relapsed for extended periods of time (duration M = 112 days), longest lasting symptoms included the inability to exercise (M = 106.5 days), fatigue (M = 101.7 days) and difficulty concentrating, associated with memory impairment (M = 101.1 days). Participants reported extreme pressure at the base of the head, syncope, sharp or sudden chest pain, and "brain pressure" among the most distressing and impacting daily life. CONCLUSIONS: Post-acute sequelae of SARS-CoV-2 infection can be characterised by a wide range of symptoms, many of which cause moderate-to-severe distress and can hinder survivors' overall well-being. RELEVANCE TO CLINICAL PRACTICE: This study advances our understanding of the symptoms of PASC and their health impacts.

10.
Clin Immunol ; 244: 109093, 2022 11.
Article in English | MEDLINE | ID: covidwho-2049018

ABSTRACT

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Emerging evidence indicates that the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is activated, which results in a cytokine storm at the late stage of COVID-19. Autophagy regulation is involved in the infection and replication of SARS-CoV-2 at the early stage and the inhibition of NLRP3 inflammasome-mediated lung inflammation at the late stage of COVID-19. Here, we discuss the autophagy regulation at different stages of COVID-19. Specifically, we highlight the therapeutic potential of autophagy activators in COVID-19 by inhibiting the NLRP3 inflammasome, thereby avoiding the cytokine storm. We hope this review provides enlightenment for the use of autophagy activators targeting the inhibition of the NLRP3 inflammasome, specifically the combinational therapy of autophagy modulators with the inhibitors of the NLRP3 inflammasome, antiviral drugs, or anti-inflammatory drugs in the fight against COVID-19.


Subject(s)
COVID-19 , Pneumonia , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antiviral Agents/pharmacology , Autophagy , Cytokine Release Syndrome , Humans , Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , SARS-CoV-2
11.
Sci Rep ; 12(1): 15905, 2022 09 23.
Article in English | MEDLINE | ID: covidwho-2042342

ABSTRACT

Long-haul COVID-19, also called post-acute sequelae of SARS-CoV-2 (PASC), is a new illness caused by SARS-CoV-2 infection and characterized by the persistence of symptoms. The purpose of this cross-sectional study was to identify a distinct and significant temporal pattern of PASC symptoms (symptom type and onset) among a nationwide sample of PASC survivors (n = 5652). The sample was randomly sorted into two independent samples for exploratory (EFA) and confirmatory factor analyses (CFA). Five factors emerged from the EFA: (1) cold and flu-like symptoms, (2) change in smell and/or taste, (3) dyspnea and chest pain, (4) cognitive and visual problems, and (5) cardiac symptoms. The CFA had excellent model fit (x2 = 513.721, df = 207, p < 0.01, TLI = 0.952, CFI = 0.964, RMSEA = 0.024). These findings demonstrate a novel symptom pattern for PASC. These findings can enable nurses in the identification of at-risk patients and facilitate early, systematic symptom management strategies for PASC.


Subject(s)
COVID-19 , COVID-19/complications , COVID-19/epidemiology , Cross-Sectional Studies , Humans , SARS-CoV-2 , Surveys and Questionnaires , Post-Acute COVID-19 Syndrome
12.
Huan Jing Ke Xue ; 43(6): 2831-2839, 2022 Jun 08.
Article in Chinese | MEDLINE | ID: covidwho-1876197

ABSTRACT

The Chinese government triggered the immediate implementation of a lockdown policy in China following the outbreak of the COVID-19 pandemic, leading to drastic decreases in air pollutant emissions. However, concentrations of PM2.5 and other pollutants increased during the COVID-19 lockdown over the Jing-Jin-Ji region compared with those averaged over 2015-2019, and two PM2.5 pollution events occurred during the lockdown. Using the ERA5 reanalysis data, we found that the Jing-Jin-Ji region during the COVID-19 lockdown was characterized by higher relative humidity, lower planetary boundary layer height, and anomalous updraft. These conditions were favorable for condensation and the secondary formation of aerosols and prevented turbulent diffusion of pollutants. Furthermore, we conducted sensitivity tests using the WRF-Chem model and found that ρ(PM2.5) increased by 20-55 µg·m-3(60%-170%) over the middle region of Jing-Jin-Ji during the COVID-19 lockdown due to changes in meteorological conditions. Furthermore, the enhanced aerosol chemistry and unfavorable diffusion conditions were identified as the key factors driving increases in PM2.5 concentrations during the lockdown. Planetary boundary layer height and relative humidity may become the important factors in forecasting PM2.5 pollution events over the Jing-Jin-Ji region under the background of emission reduction.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Aerosols/analysis , Air Pollutants/analysis , Air Pollution/analysis , COVID-19/epidemiology , COVID-19/prevention & control , China/epidemiology , Communicable Disease Control , Environmental Monitoring , Humans , Pandemics/prevention & control , Particulate Matter/analysis
13.
Appl Res Qual Life ; 17(5): 3175-3198, 2022.
Article in English | MEDLINE | ID: covidwho-1859093

ABSTRACT

The use of electronic service-learning (e-Service-Learning or e-SL) is valuable under COVID-19 because we can provide the service without physical contact. Unfortunately, evaluation of e-SL is not widespread and there is no known study in different Chinese societies. Besides, there are many methodological limitations of the existing studies in the field. In this paper, we evaluated e-SL projects implemented in summer 2020 and 2021 in three sites in China. First, we examined service providers' changes based on pretest and posttest scores (i.e., objective outcome evaluation) and their perceptions of the e-SL projects (i.e., subjective outcome evaluation based on the service providers). Second, graduate student assessors in Chinese mainland universities and teachers of primary school students (i.e., service recipients) rated the SL program quality, service providers' performance and benefits to the service recipients after program completion (i.e., subjective outcome evaluation of SL projects based on other stakeholders). Third, trained graduate student assessors evaluated service quality during the implementation process (i.e., process evaluation). We found that university students (i.e., service providers) showed higher posttest scores in positive youth development attributes, leadership attributes and life satisfaction relative to pretest scores. Besides, service providers showed positive perceptions of their learning experience, own performance, benefits to the service recipients and themselves in the SL projects. Similarly, other stakeholders also had positive evaluation of the SL projects and related benefits. Finally, trained graduate student assessors had positive assessment of the quality of program implementation. The findings underscore the utility of e-SL involving both online teaching and learning as well as online service, particularly in a Chinese context.

14.
Journal of Shandong University ; 58(4):65-70, 2020.
Article in English, Chinese | GIM | ID: covidwho-1812835

ABSTRACT

Objective: To investigate the clinical characteristics of corona virus disease 2019 (COVID-19) patients in Wuhan City, and the correlation between inflammatory factors and severity.

15.
Front Public Health ; 9: 809987, 2021.
Article in English | MEDLINE | ID: covidwho-1662636

ABSTRACT

The COVID-19 infections have profoundly and negatively impacted the whole world. Hence, we have modeled the dynamic spread of global COVID-19 infections with the connectedness approach based on the TVP-VAR model, using the data of confirmed COVID-19 cases during the period of March 23rd, 2020 to September 10th, 2021 in 18 countries. The results imply that, (i) the United States, the United Kingdom and Indonesia are global epidemic centers, among which the United States has the highest degree of the contagion of the COVID-19 infections, which is stable. South Korea, France and Italy are the main receiver of the contagion of the COVID-19 infections, and South Korea has been the most severely affected by the overseas epidemic; (ii) there is a negative correlation between the timeliness, effectiveness and mandatory nature of government policies and the risk of the associated countries COVID-19 epidemic affecting, as well as the magnitude of the net contagion of domestic COVID-19; (iii) the severity of domestic COVID-19 epidemics in the United States and Canada, Canada and Mexico, Indonesia and Canada is almost equivalent, especially for the United States, Canada and Mexico, whose domestic epidemics are with the same tendency; (iv) the COVID-19 epidemic has spread though not only the central divergence manner and chain mode of transmission, but also the way of feedback loop. Thus, more efforts should be made by the governments to enhance the pertinence and compulsion of their epidemic prevention policies and establish a systematic and efficient risk assessment mechanism for public health emergencies.


Subject(s)
COVID-19 , Epidemics , Humans , Italy , Public Health , SARS-CoV-2 , United States/epidemiology
16.
EPMA J ; 12(3): 307-324, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1544595

ABSTRACT

AIMS: Coronavirus disease 2019 (COVID-19) is rapidly spreading worldwide. Drug therapy is one of the major treatments, but contradictory results of clinical trials have been reported among different individuals. Furthermore, comprehensive analysis of personalized pharmacotherapy is still lacking. In this study, analyses were performed on 47 well-characterized COVID-19 drugs used in the personalized treatment of COVID-19. METHODS: Clinical trials with published results of drugs use for COVID-19 treatment were collected to evaluate drug efficacy. Drug-to-Drug Interactions (DDIs) were summarized and classified. Functional variations in actionable pharmacogenes were collected and systematically analysed. "Gene Score" and "Drug Score" were defined and calculated to systematically analyse ethnicity-based genetic differences, which are important for the safer use of COVID-19 drugs. RESULTS: Our results indicated that four antiviral agents (ritonavir, darunavir, daclatasvir and sofosbuvir) and three immune regulators (budesonide, colchicine and prednisone) as well as heparin and enalapril could generate the highest number of DDIs with common concomitantly utilized drugs. Eight drugs (ritonavir, daclatasvir, sofosbuvir, ribavirin, interferon alpha-2b, chloroquine, hydroxychloroquine (HCQ) and ceftriaxone had actionable pharmacogenomics (PGx) biomarkers among all ethnic groups. Fourteen drugs (ritonavir, daclatasvir, prednisone, dexamethasone, ribavirin, HCQ, ceftriaxone, zinc, interferon beta-1a, remdesivir, levofloxacin, lopinavir, human immunoglobulin G and losartan) showed significantly different pharmacogenomic characteristics in relation to the ethnic origin of the patient. CONCLUSION: We recommend that particularly for patients with comorbidities to avoid serious DDIs, the predictive, preventive, and personalized medicine (PPPM, 3 PM) strategies have to be applied for COVID-19 treatment, and genetic tests should be performed for drugs with actionable pharmacogenes, especially in some ethnic groups with a higher frequency of functional variations, as our analysis showed. We also suggest that drugs associated with higher ethnic genetic differences should be given priority in future pharmacogenetic studies for COVID-19 management. To facilitate translation of our results into clinical practice, an approach conform with PPPM/3 PM principles was suggested. In summary, the proposed PPPM/3 PM attitude should be obligatory considered for the overall COVID-19 management. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13167-021-00247-0.

17.
Mathematics ; 9(21):2719, 2021.
Article in English | MDPI | ID: covidwho-1488666

ABSTRACT

In this paper, we provide a mathematical and statistical methodology using heteroscedastic estimation to achieve the aim of building a more precise mathematical model for complex financial data. Considering a general regression model with explanatory variables (the expected value model form) and the error term (including heteroscedasticity), the optimal expected value and heteroscedastic model forms are investigated by linear, nonlinear, curvilinear, and composition function forms, using the minimum mean-squared error criterion to show the precision of the methodology. After combining the two optimal models, the fitted values of the financial data are more precise than the linear regression model in the literature and also show the fitted model forms in the example of Taiwan stock price index futures that has three cases: (1) before COVID-19, (2) during COVID-19, and (3) the entire observation time period. The fitted mathematical models can apparently show how COVID-19 affects the return rates of Taiwan stock price index futures. Furthermore, the fitted heteroscedastic models also show how COVID-19 influences the fluctuations of the return rates of Taiwan stock price index futures. This methodology will contribute to the probability of building algorithms for computing and predicting financial data based on mathematical model form outcomes and assist model comparisons after adding new data to a database.

18.
Pharmacol Res ; 163: 105224, 2021 01.
Article in English | MEDLINE | ID: covidwho-1364404

ABSTRACT

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.


Subject(s)
Acute Lung Injury/drug therapy , Lung/drug effects , Phytochemicals/pharmacology , Respiratory Distress Syndrome/drug therapy , Acute Lung Injury/etiology , Acute Lung Injury/metabolism , Acute Lung Injury/pathology , Animals , Humans , Lung/metabolism , Lung/pathology , Phytochemicals/isolation & purification , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/pathology , Signal Transduction
19.
Zhongguo Huanjing Kexue = China Environmental Science ; 41(5):1985, 2021.
Article in English | ProQuest Central | ID: covidwho-1257861

ABSTRACT

The influence of meteorological conditions on the pollution processes was investigated in this study by analyzing the changes of air quality as well as the characteristics of two persistent heavy pollution episodes during the Coronavirus Disea se 2019(COVID-19) prevention(January 24 to February 29) of 2020 winter compared with the same period of 2015~2019. Cold air intensity in 2020 winter was weaker with the cold surges frequency decreased by 50%. Air temperature was 0.73℃ higher, and wind speed and mixed layer height were 17.8% and 32.5% lower, respectively. Relative humidity and dew point temperature increased by 60. 9% and 48.1%, respectively. Northerly wind frequency reduced 7.5% while both of southerly and easterly wind increased 6.0%. As shown above, all meteorological conditions in 2020 winter were significantly more favorable for air pollution than the same historical period. Moreover, two heavy pollution episodes(January 24~29 and February 8~14) lasted for 59 and 75 hours were analyzed. At the cumulative stage, regional transport that can be divided into east and south channel greatly affected PM2.5, with the contribution of 70% and 58% for two episodes. By contrast, the contribution of local pollution was 67% and 48%, respectively, indicating the increased proportion of hygroscopic growth and secondary generation in the maintenance and aggravation stages. Under the meteorological background of "high humidity and high atmospheric stability", the combined effects of atmospheric vertical dynamics and horizontal convergence accumulated PM2.5 and water vapor in Beijing plain and prevented them from spreading beyond the boundary layer. Further bidirectional feedback between increased pollutants and meteorological factor s in stable boundary layer resulting in aggravation of pollution. According to EMI index, meteorological conditions during the epi demic prevention in 2020 winter caused an increase of 70.1% in PM2.5 concentration compared to pre-COVID-19. Emissions reduction caused by emergency measures for COVID-19 lockdown offset 53% of the adverse impact induced by meteorological conditions. As for the two episodes in 2020 winter, EMI was 26.9% and 19.7% larger than the average of other nine episodes in the correspond ing period of 2015~2019, and PM2.5 concentration was basically unchanged or slightly reduced. Overall, if the current social emission level is not changed, emission reduction caused by city blockade under special circumstances can only partially reduce the pollution concentration, however, cannot completely offset the adverse impact of meteorological conditions.

20.
J Transl Med ; 18(1): 274, 2020 07 06.
Article in English | MEDLINE | ID: covidwho-657615

ABSTRACT

BACKGROUND: Since the outbreak of coronavirus disease 2019 (COVID-19), many researchers in China have performed related clinical research. However, systematic reviews of the registered clinical trials are still lacking. Therefore, we conducted a systematic review of clinical trials for COVID-19 to summarize their characteristics. METHODS: This study is based on the PRISMA recommendations in the Cochrane handbook. The Chinese Clinical Registration Center and the ClinicalTrials.gov databases were searched to identify registered clinical trials related to COVID-19. The retrieval inception date was February 9, 2020. Two researchers independently selected the literature based on the inclusion and exclusion criteria, extracted data, and evaluated the risk of bias. RESULTS: A total of 75 registered clinical trials (63 interventional studies and 12 observational studies) for COVID-19 were identified. The majority of clinical trials were sponsored by Chinese hospitals. Only 11 trials have begun to recruit patients, and none of the registered clinical trials have been completed; 34 trials were early clinical exploratory trials or in the pre-experiment stage, 13 trials were phase III, and four trials were phase IV. The intervention methods included traditional Chinese medicine in 26 trials, Western medicine in 30 trials, and integrated traditional Chinese medicine and Western medicine in 19 trials. The subjects were primarily non-critical adult patients (≥ 18 years old). The median sample size of the trials was 100 (IQR: 60-200), and the median length of the trial periods was 179 d (IQR: 94-366 d). The main outcomes were clinical observation and examinations. Overall, the methodological quality of both the interventional trials and observational studies was low. CONCLUSIONS: Intensive clinical trials on the treatment of COVID-19 using traditional Chinese medicine and Western medicine are ongoing or will be performed in China. However, based on the uncertain methodological quality, small sample size, and long trial duration, we will not be able to obtain reliable, high-quality clinical evidence regarding the treatment of COVID-19 in the near future. Improving the quality of study design, prioritizing promising drugs, and using different designs and statistical methods are worth advocating and recommending for clinical trials of COVID-19 in the future.


Subject(s)
Betacoronavirus/physiology , Clinical Trials as Topic , Coronavirus Infections/virology , Pneumonia, Viral/virology , COVID-19 , Humans , Observational Studies as Topic , Pandemics , Publication Bias , Risk , SARS-CoV-2 , Treatment Outcome
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