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1.
IEEE J Biomed Health Inform ; 26(6): 2458-2468, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1878966

ABSTRACT

Despite efforts made to model and predict COVID-19 transmission, large predictive uncertainty remains. Failure to understand the dynamics of the nonlinear pandemic prediction model is an important reason. To this end, local and multiple global sensitivity analysis approaches are synthetically applied to analyze the sensitivities of parameters and initial state variables and community size (N) in susceptible-infected-recovered (SIR) and its variant susceptible-exposed-infected-recovered (SEIR) models and basic reproduction number (R0), aiming to provide prior information for parameter estimation and suggestions for COVID-19 prevention and control measures. We found that N influences both the maximum number of actively infected cases and the date on which the maximum number of actively infected cases is reached. The high effect of N on maximum actively infected cases and peak date suggests the necessity of isolating the infected cases in a small community. The protection rate and average quarantined time are most sensitive to the infected populations, with a summation of their first-order sensitivity indices greater than 0.585, and their interactions are also substantial, being 0.389 and 0.334, respectively. The high sensitivities and interaction between the protection rate and average quarantined time suggest that protection and isolation measures should always be implemented in conjunction and started as early as possible. These findings provide insights into the predictability of the pandemic models by estimating influential parameters and suggest how to effectively prevent and control epidemic transmission.


Subject(s)
COVID-19 , Pandemics , Basic Reproduction Number , COVID-19/epidemiology , Humans , Quarantine , SARS-CoV-2
2.
Atmospheric Chemistry and Physics ; 22(7):4853-4866, 2022.
Article in English | ProQuest Central | ID: covidwho-1786221

ABSTRACT

The outbreak of COVID-19 promoted strict restrictions to human activities in China, which led to a dramatic decrease in most air pollutant concentrations (e.g., PM2.5, PM10, NOx, SO2 and CO). However, an obvious increase in ozone (O3) concentrations was found during the lockdown period in most urban areas of China. In this study, we conducted field measurements targeting ozone and its key precursors by utilizing a novel proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) in Changzhou, which is representative of the Yangtze River Delta (YRD) city cluster of China. We further applied the integrated methodology including machine learning, an observation-based model (OBM) and sensitivity analysis to obtain insights into the reasons causing the obvious increase in ozone. Major findings include the following: (1) by deweathered calculation, we found changes in precursor emissions contributed 1.46 ppbv to the increase in the observed O3 during the full-lockdown period in 2020, while meteorology constrained 3.0 ppbv of O3 in the full-lockdown period of 2019. (2) By using an OBM, we found that although a significant reduction in O3 precursors was observed during the full-lockdown period, the photochemical formation of O3 was stronger than that during the pre-lockdown period. (3) The NOx/VOC ratio dropped dramatically from 1.84 during the pre-lockdown to 0.79 in the full-lockdown period, which switched O3 formation from a VOC-limited regime to the boundary of a NOx- and VOC-limited regime. Additionally, box model results suggested that the decrease in the NOx/VOC ratio during the full-lockdown period could increase the mean O3 by 2.4 ppbv. Results of this study give insights into the relationship between O3 and its precursors in urban area and demonstrate reasons for the obvious increase in O3 in most urban areas of China during the COVID-19 lockdown period. This study also underlines the necessity of controlling anthropogenic oxygenated volatile organic compounds (OVOCs), alkenes and aromatics in the sustained campaign of reducing O3 pollution in China.

3.
Nat Biomed Eng ; 6(3): 286-297, 2022 03.
Article in English | MEDLINE | ID: covidwho-1751719

ABSTRACT

CRISPR-based assays for the detection of nucleic acids are highly specific, yet they are not fast, sensitive or easy to use. Here we report a one-step fluorescence assay for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in nasopharyngeal samples, with a sample-to-answer time of less than 20 minutes and a sensitivity comparable to that of quantitative real-time PCR with reverse transcription (RT-qPCR). The assay uses suboptimal protospacer adjacent motifs, allowing for flexibility in the design of CRISPR RNAs and slowing down the kinetics of Cas12a-mediated collateral cleavage of fluorescent DNA reporters and cis cleavage of substrates, which leads to stronger fluorescence owing to the accumulation of amplicons generated by isothermal recombinase polymerase amplification. In a set of 204 nasopharyngeal samples with RT-qPCR cycle thresholds ranging from 18.1 to 35.8, the assay detected SARS-CoV-2 with a sensitivity of 94.2% and a specificity of 100%, without the need for RNA extraction. Rapid and sensitive assays for nucleic acid testing in one pot that allow for flexibility in assay design may aid the development of reliable point-of-care nucleic acid testing.


Subject(s)
COVID-19 , RNA, Viral , COVID-19/diagnosis , CRISPR-Cas Systems , Humans , RNA, Viral/genetics , SARS-CoV-2/genetics , Sensitivity and Specificity
4.
Huan Jing Ke Xue ; 43(2): 878-886, 2022 Feb 08.
Article in Chinese | MEDLINE | ID: covidwho-1643943

ABSTRACT

In order to reveal the pollution characteristics and risk levels of DBPs in typical drinking water sources in Wuhan under the COVID-19 pandemic, 26 sampling sites were selected in typical drinking water sources in Wuhan. N,N-diethyl-1,4-phenylenediamine spectrophotometry and gas chromatograph-micro-cell electron capture detector (GC-µECD) methods were used to detect residual chlorine disinfectants and DBPs in water, respectively, and their health and ecology risks were assessed. The results showed that free chlorine or total residual chlorine were detected in 16 of the 26 water samples, and the maximum concentration was 0.04 mg·L-1, which exceeded the limit of the surface water standard in China. The concentration of residual chlorine was higher in sampling sites near the outfall of a municipal sewage plant. There were 34 types of DBPs measured in 10 sampling sites, and 24 types of substances were detected with the detection rate of 10.00%-100.00%. The ρ (total DBPs) was in the range of 0.11-104.73 µg·L-1, with an average value of 7.26 µg·L-1. The concentration of chloroform was the highest among all the DBPs, ranging from 9.98 µg·L-1 to 11.15 µg·L-1, with an average value of 10.47 µg·L-1. The concentration of 2-bromo-2-iodoacetamide was the lowest, ranging from ND-0.11 µg·L-1, with an average value of 0.01 µg·L-1. The overall detection level of the DBPs area was low in this study area, and the result of the health risk assessment showed that the DBPs had no carcinogenic or non-carcinogenic health risks to human body. However, the results of the ecological risk assessment showed that chloroform presented a high ecological risk to aquatic organisms.


Subject(s)
COVID-19 , Disinfectants , Drinking Water , Water Pollutants, Chemical , Water Purification , Disinfectants/analysis , Disinfection , Drinking Water/analysis , Halogenation , Humans , Pandemics , Risk Assessment , SARS-CoV-2 , Water Pollutants, Chemical/analysis
5.
Asian J Surg ; 45(2): 814-815, 2022 02.
Article in English | MEDLINE | ID: covidwho-1588265
6.
Signal Transduct Target Ther ; 6(1): 347, 2021 09 25.
Article in English | MEDLINE | ID: covidwho-1437669

ABSTRACT

SARS-CoV-2 mutations contribute to increased viral transmissibility and immune escape, compromising the effectiveness of existing vaccines and neutralizing antibodies. An in-depth investigation on COVID-19 pathogenesis is urgently needed to develop a strategy against SARS-CoV-2 variants. Here, we identified CD147 as a universal receptor for SARS-CoV-2 and its variants. Meanwhile, Meplazeumab, a humanized anti-CD147 antibody, could block cellular entry of SARS-CoV-2 and its variants-alpha, beta, gamma, and delta, with inhibition rates of 68.7, 75.7, 52.1, 52.1, and 62.3% at 60 µg/ml, respectively. Furthermore, humanized CD147 transgenic mice were susceptible to SARS-CoV-2 and its two variants, alpha and beta. When infected, these mice developed exudative alveolar pneumonia, featured by immune responses involving alveoli-infiltrated macrophages, neutrophils, and lymphocytes and activation of IL-17 signaling pathway. Mechanistically, we proposed that severe COVID-19-related cytokine storm is induced by a "spike protein-CD147-CyPA signaling axis": Infection of SARS-CoV-2 through CD147 initiated the JAK-STAT pathway, which further induced expression of cyclophilin A (CyPA); CyPA reciprocally bound to CD147 and triggered MAPK pathway. Consequently, the MAPK pathway regulated the expression of cytokines and chemokines, which promoted the development of cytokine storm. Importantly, Meplazumab could effectively inhibit viral entry and inflammation caused by SARS-CoV-2 and its variants. Therefore, our findings provided a new perspective for severe COVID-19-related pathogenesis. Furthermore, the validated universal receptor for SARS-CoV-2 and its variants can be targeted for COVID-19 treatment.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Monoclonal, Humanized/pharmacology , Basigin/antagonists & inhibitors , Basigin/metabolism , COVID-19/drug therapy , COVID-19/metabolism , Cytokine Release Syndrome/drug therapy , SARS-CoV-2/metabolism , Angiotensin-Converting Enzyme 2/genetics , Animals , Basigin/genetics , COVID-19/genetics , Chlorocebus aethiops , Cytokine Release Syndrome/genetics , Cytokine Release Syndrome/metabolism , Humans , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/genetics , Mice , Mice, Transgenic , SARS-CoV-2/genetics , Vero Cells
8.
Int J Clin Pract ; 75(7): e14257, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1197145

ABSTRACT

BACKGROUND: Novel coronavirus disease 2019 (COVID-19) poses a huge threat to the global public health. This study aimed to identify predictive indicators of severe COVID-19. METHODS: We retrospectively collected clinical data on hospital admission of all patients with severe COVID-19 and a control cohort (1:1) of gender- and hospital-matched patients with mild disease from 13 designated hospitals in the Hebei Province between 22 January and 15 April 2020. RESULTS: A total of 104 patients (52 with severe COVID-19 and 52 with mild disease) were included. Only age, fever, duration from symptom onset to confirmation, respiratory rate, percutaneous oxygen saturation (SpO2 ) and neutrophilic percentage were independent predictors of severe COVID-19. Age and neutrophilic percentage performed best in predicting severe COVID-19, followed by SpO2 . 'Age + neutrophilic percentage' (the sum of age and neutrophilic percentage) (area under the curve [AUC] 0.900, 95% confidence interval [CI] 0.825-0.950, P < .001) and 'age and neutrophilic percentage' (the prediction probability of age and neutrophilic percentage for severe type obtained by logistic regression analysis) (AUC 0.899, 95% CI 0.824-0.949, P < .001) had excellent predictive performance for severe type. The optimal cut-off for 'age + neutrophilic percentage' was >119.1 (sensitivity, 86.5%; specificity, 84.6%; Youden index, 0.712). CONCLUSION: The combination of age and neutrophil percentage could effectively predict severe COVID-19. The sum of age and neutrophil percentage was recommended for clinical application because of its excellent predictive value and practicability. TRAIL REGISTRATION: China Clinical Trial Registry, number ChiCTR2000030226. Registered 26 February 2020-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=49855.


Subject(s)
COVID-19 , China/epidemiology , Humans , Neutrophils , Prognosis , Retrospective Studies , SARS-CoV-2
9.
Otolaryngol Head Neck Surg ; 163(1): 121-131, 2020 07.
Article in English | MEDLINE | ID: covidwho-913955

ABSTRACT

Objective. To describe coronavirus disease 2019 (COVID-19) patient presentations requiring otolaryngology consultation and provide recommendations for protective measures based on the experience of ear, nose, and throat (ENT) departments in 4 Chinese hospitals during the COVID-19 pandemic. Study Design. Retrospective case series. Setting. Multicenter. Subjects and Methods. Twenty hospitalized COVID-19 patients requiring ENT consultation from 3 designated COVID-19 hospitals in Wuhan, Shanghai, and Shenzhen were identified. Data on demographics, comorbidities, COVID-19 symptoms and severity, consult reason, treatment, and personal protective equipment (PPE) use were collected and analyzed. Infection control strategies implemented for ENT outpatients and emergency room visits at the Eye and ENT Hospital of Fudan University were reported. Results. Median age was 63 years, 55% were male, and 95% were in severe or critical condition. Six tracheotomies were performed. Posttracheotomy outcomes were mixed (2 deaths, 2 patients comatose, all living patients still hospitalized). Other consults included epistaxis, pharyngitis, nasal congestion, hyposmia, rhinitis, otitis externa, dizziness, and tinnitus. At all hospitals, powered air-supply filter respirators (PAPRs) were used for tracheotomy or bleeding control. PAPR or N95-equivalent masks plus full protective clothing were used for other complaints. No inpatient ENT providers were infected. After implementation of infection control strategies for outpatient clinics, emergency visits, and surgeries, no providers were infected at the Eye and ENT Hospital of Fudan University. Conclusions and Relevance. COVID-19 patients require ENT consultation for many reasons, including tracheotomy. Otolaryngologists play an indispensable role in the treatment of COVID-19 patients but, due to their work, are at high risk of exposure. Appropriate protective strategies can prevent infection of otolaryngologists.


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Disease Transmission, Infectious/prevention & control , Otolaryngology/standards , Otorhinolaryngologic Diseases/therapy , Pandemics , Personal Protective Equipment/standards , Pneumonia, Viral/epidemiology , Adult , Aged , COVID-19 , China/epidemiology , Coronavirus Infections/complications , Coronavirus Infections/transmission , Female , Humans , Male , Middle Aged , Otorhinolaryngologic Diseases/complications , Pneumonia, Viral/complications , Pneumonia, Viral/transmission , Retrospective Studies , SARS-CoV-2
10.
Front Public Health ; 8: 205, 2020.
Article in English | MEDLINE | ID: covidwho-854039

ABSTRACT

The COVID-19 outbreak spread rapidly throughout the globe, with worldwide infections and deaths continuing to increase dramatically. To control disease spread and protect healthcare workers, accurate information is necessary. We searched PubMed and Google Scholar for studies published from December 2019 to March 31, 2020 with the terms "COVID-19," "2019-nCoV," "SARS-CoV-2," or "Novel Coronavirus Pneumonia." The main symptoms of COVID-19 are fever (83-98.6%), cough (59.4-82%), and fatigue (38.1-69.6%). However, only 43.8% of patients have fever early in the disease course, despite still being infectious. These patients may present to clinics lacking proper precautions, leading to nosocomial transmission, and infection of workers. Potential COVID-19 cases must be identified early to initiate proper triage and distinguish them quickly from similar infections. Early identification, accurate triage, and standardized personal protection protocols can reduce the risk of cross infection. Containing disease spread will require protecting healthcare workers.


Subject(s)
COVID-19 , Cough/etiology , Fever/etiology , Health Personnel/statistics & numerical data , COVID-19/diagnosis , COVID-19/transmission , Global Health , Humans , Infection Control , Risk Assessment , SARS-CoV-2
11.
SSRN; 2020.
Preprint | SSRN | ID: ppcovidwho-642

ABSTRACT

Backgrounds: A novel coronavirus disease 2019 (COVID-19) occurred in Wuhan and rapidly spread elsewhere. The clinical characteristics and treatment of critical

12.
Nano lett ; 2020.
Article in English | MEDLINE | ID: covidwho-662331

ABSTRACT

Continued improvement in the electrochemical performance of Li-Mn-O oxide cathode materials is key to achieving advanced low-cost Li-ion batteries with high energy densities. In this study, O2-type Li0.78[Li0.24Mn0.76]O2 nanowires were synthesized by a solvothermal reaction to produce P2-type Na5/6[Li1/4Mn3/4]O2 nanowires, which were then subjected to molten salt Li-ion exchange. The resulting nanowires have diameters less than 20 nm and lengths of several micrometers. The full-Mn-based nanowires cathode material delivers a reversible capacity of 275 mAh g-1 at 0.1 C and 200 mAh g-1 at a high current rate of 15 C with a capacity retention of more than 80% and the voltage decay was dramatically suppressed after 100 cycles. This excellent performance is ascribed to the highly stable oxygen redox reaction and lack of layered-to-spinel phase transition in the O2-type structure during cycling.

13.
Front Med (Lausanne) ; 7: 518, 2020.
Article in English | MEDLINE | ID: covidwho-760866

ABSTRACT

Background: Despite an increase in the familiarity of the medical community with the epidemiological and clinical characteristics of coronavirus disease 2019 (COVID-19), there is presently a lack of rapid and effective risk stratification indicators to predict the poor clinical outcomes of COVID-19 especially in severe patients. Methods: In this retrospective single-center study, we included 117 cases confirmed with COVID-19. The clinical, laboratory, and imaging features were collected and analyzed during admission. The Multi-lobular infiltration, hypo-Lymphocytosis, Bacterial coinfection, Smoking history, hyper-Tension and Age (MuLBSTA) Score and Confusion, Urea, Respiratory rate, Blood pressure, Age 65 (CURB65) score were used to assess the death and intensive care unit (ICU) risks in all patients. Results: Among of all 117 hospitalized patients, 21 (17.9%) patients were admitted to the ICU care, and 5 (4.3%) patients were died. The median hospital stay was 12 (10-15) days. There were 18 patients with MuLBSTA score ≥ 12 points and were all of severe type. In severe type, ICU care and death patients, the proportion with MuLBSTA ≥ 12 points were greater than that of CURB65 score ≥ 3 points (severe type patients, 50 vs. 27.8%; ICU care, 61.9 vs. 19.0%; death, 100 vs. 40%). For the MuLBSTA score, the ROC curve showed good efficiency of diagnosis death (area under the curve [AUC], 0.956; cutoff value, 12; specificity, 89.5%; sensitivity, 100%) and ICU care (AUC, 0.875; cutoff value, 11; specificity, 91.7%; sensitivity, 71.4%). The K-M survival analysis showed that patients with MuLBSTA score ≥ 12 had higher risk of ICU (log-rank, P = 0.001) and high risk of death (log-rank, P = 0.000). Conclusions: The MuLBSTA score is valuable for risk stratification and could effectively screen high-risk patients at admission. The higher score at admission have higher risk of ICU care and death in patients infected with COVID.

15.
Ann Palliat Med ; 9(4): 2118-2130, 2020 Jul.
Article in English | MEDLINE | ID: covidwho-658658

ABSTRACT

BACKGROUND: In December, 2019, a novel coronavirus disease 2019 (COVID-19) emerged in Wuhan, China. We aimed to clarify the epidemiology, laboratory examinations, imaging findings, and treatment of critically ill patients with COVID-19 in Hebei province, China. METHODS: In this retrospective study, the demographic, laboratory and imaging, and treatment data of patients with severe COVID-19 treated in 13 designated hospitals in Hebei were collected and analyzed. RESULTS: A total of 319 severe COVID-19 patients were treated at the 13 designated hospitals between 22 January, 2020 and 25 March, 2020. Eventually, 51 critically ill (31 severe cases and 20 critically severe cases) patients were included in the analysis. The patients had an average age of 58.9±13.7 years, and 27 (52.9%) were men. Twenty-one (41.2%) were familial cluster, and 33 (64.7%) had chronic illnesses. The patients in critically severe group had longer duration from symptom to confirmation, more severe infections, more severe lung injury, and a lower percentage of lymphocytes. All 51 patients received antiviral drugs, 47 (92.2%) received antibacterial agents, 49 (96.1%) received traditional Chinese drugs, and 46 (90.2%) received methylprednisolone. The critically severe patients received more fluid and more diuretic treatment; 14 (70.0%) required invasive mechanical ventilation, and 13 (65.0%) developed extrapulmonary complications. CONCLUSIONS: COVID-19 patients who had underlying diseases and longer confirmation times were more likely to progress to critically severe COVID-19. These patients also presented with a higher risk of respiratory depression, circulatory collapse, extrapulmonary complications, and infection.


Subject(s)
Coronavirus Infections/diagnosis , Coronavirus Infections/therapy , Pneumonia, Viral/diagnosis , Pneumonia, Viral/therapy , Aged , COVID-19 , China/epidemiology , Coronavirus Infections/epidemiology , Critical Care , Critical Illness , Female , Humans , Intensive Care Units , Male , Middle Aged , Pandemics , Pneumonia, Viral/epidemiology , Retrospective Studies
16.
Environ. Sci. Techno. Lett. ; 6(7): 402-408, 20200609.
Article in English | WHO COVID, ELSEVIER | ID: covidwho-628338

ABSTRACT

The COVID-19 outbreak in China led to dramatic changes in human activities resulting from the sudden infection prevention and control measures. Here, we use ground-level observations and model simulations to examine the nationwide spatial-temporal variations of six air pollutants before and after the initiation of First-Level Public Health Emergency Response. The level of ambient NO2 declined significantly, and in most cities, the decline was dominated by reduced emissions. Meanwhile, the level of O3 increased significantly during this period, and the nonmeteorological factors explained the increase. For the other air pollutants (PM2.5, SO2, and CO), the observed declines on the national scale were obviously affected by the meteorological conditions. In Wuhan, significant declines were found for air pollutants except O3 and emissions dominated the changes, while in Beijing during the same period, only the level of NO2 significantly declined. This study clearly shows that the meteorological changes contributed substantially to the observed changes in most air pollutants, and this must be considered in evaluating the impacts of pollutant source changes on air quality during the specific event and in assessing source-oriented risks.

17.
Sci Total Environ ; 732: 139282, 2020 Aug 25.
Article in English | MEDLINE | ID: covidwho-268426

ABSTRACT

The outbreak of COVID-19 has spreaded rapidly across the world. To control the rapid dispersion of the virus, China has imposed national lockdown policies to practise social distancing. This has led to reduced human activities and hence primary air pollutant emissions, which caused improvement of air quality as a side-product. To investigate the air quality changes during the COVID-19 lockdown over the YRD Region, we apply the WRF-CAMx modelling system together with monitoring data to investigate the impact of human activity pattern changes on air quality. Results show that human activities were lowered significantly during the period: industrial operations, VKT, constructions in operation, etc. were significantly reduced, leading to lowered SO2, NOx, PM2.5 and VOCs emissions by approximately 16-26%, 29-47%, 27-46% and 37-57% during the Level I and Level II response periods respectively. These emission reduction has played a significant role in the improvement of air quality. Concentrations of PM2.5, NO2 and SO2 decreased by 31.8%, 45.1% and 20.4% during the Level I period; and 33.2%, 27.2% and 7.6% during the Level II period compared with 2019. However, ozone did not show any reduction and increased greatly. Our results also show that even during the lockdown, with primary emissions reduction of 15%-61%, the daily average PM2.5 concentrations range between 15 and 79 µg m-3, which shows that background and residual pollutions are still high. Source apportionment results indicate that the residual pollution of PM2.5 comes from industry (32.2-61.1%), mobile (3.9-8.1%), dust (2.6-7.7%), residential sources (2.1-28.5%) in YRD and 14.0-28.6% contribution from long-range transport coming from northern China. This indicates that in spite of the extreme reductions in primary emissions, it cannot fully tackle the current air pollution. Re-organisation of the energy and industrial strategy together with trans-regional joint-control for a full long-term air pollution plan need to be further taken into account.


Subject(s)
Air Pollution , Betacoronavirus , Coronavirus Infections , Pandemics , Pneumonia, Viral , Air Pollutants , COVID-19 , China , Environmental Monitoring , Human Activities , Humans , Particulate Matter , SARS-CoV-2
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