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1.
Environ Int ; 176: 107967, 2023 06.
Article in English | MEDLINE | ID: covidwho-20238659

ABSTRACT

BACKGROUND: A large gap exists between the latest Global Air Quality Guidelines (AQG 2021) and Chinese air quality standards for NO2. Assessing whether and to what extent air quality standards for NO2 should be tightened in China requires a comprehensive understanding of the spatiotemporal characteristics of population exposure to ambient NO2 and related health risks, which have not been studied to date. OBJECTIVE: We predicted ground NO2 concentrations with high resolution in mainland China, explored exposure characteristics to NO2 pollution, and assessed the mortality burden attributable to NO2 exposure. METHODS: Daily NO2 concentrations in 2019 were predicted at 1-km spatial resolution in mainland China using random forest models incorporating multiple predictors. From these high-resolution predictions, we explored the spatiotemporal distribution of NO2, population and area percentages with NO2 exposure exceeding criterion levels, and premature deaths attributable to long- and short-term NO2 exposure in China. RESULTS: The cross-validation R2and root mean squared error of the NO2 predicting model were 0.80 and 7.78 µg/m3, respectively,at the daily level in 2019.The percentage of people (population number) with annual NO2 exposure over 40 µg/m3 in mainland China in 2019 was 10.40 % (145,605,200), and it reached 99.68 % (1,395,569,840) with the AQG guideline value of 10 µg/m3. NO2 levels and population exposure risk were elevated in urban areas than in rural. Long- and short-term exposures to NO2 were associated with 285,036 and 121,263 non-accidental deaths, respectively, in China in 2019. Tightening standards in steps gradually would increase the potential health benefit. CONCLUSION: In China, NO2 pollution is associated with significant mortality burden. Spatial disparities exist in NO2 pollution and exposure risks. China's current air quality standards may no longer objectively reflect the severity of NO2 pollution and exposure risk. Tightening the national standards for NO2 is needed and will lead to significant health benefits.


Subject(s)
Air Pollutants , Air Pollution , Humans , Air Pollutants/analysis , Nitrogen Dioxide/analysis , Air Pollution/adverse effects , Air Pollution/analysis , China/epidemiology , Risk Factors , Particulate Matter/analysis , Environmental Exposure/adverse effects
2.
Biosens Bioelectron ; 219: 114816, 2022 Oct 17.
Article in English | MEDLINE | ID: covidwho-2242673

ABSTRACT

Airborne transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the urgent need for aerosol monitoring of SARS-CoV-2 to prevent sporadic outbreaks of COVID-19. The inadequate sensitivity of conventional methods and the lack of an on-site detection system limited the practical SARS-CoV-2 monitoring of aerosols in public spaces. We have developed a novel SARS-CoV-2-in-aerosol monitoring system (SIAMs) which consists of multiple portable cyclone samplers for collecting aerosols from several venues and a sensitive "sample-to-answer" microsystem employing an integrated cartridge for the analysis of SARS-CoV-2 in aerosols (iCASA) near the sampling site. By seamlessly combining viral RNA extraction based on a chitosan-modified quartz filter and "in situ" tetra-primer recombinase polymerase amplification (tpRPA) into an integrated microfluidic cartridge, iCASA can provide an ultra-high sensitivity of 20 copies/mL, which is nearly one order of magnitude greater than that of the commercial kit, and a short turnaround time of 25 min. By testing various clinical samples of nasopharyngeal swabs, saliva, and exhaled breath condensates obtained from 23 COVID-19 patients, we demonstrate that the positive rate of our system was 3.3 times higher than those of the conventional method. Combining with multiple portable cyclone samplers, we detected 52.2% (12/23) of the aerosol samples, six times higher than that of the commercial kit, collected from the isolation wards of COVID-19 patients, demonstrating the excellent performance of our system for SARS-CoV-2-in-aerosol monitoring. We envision the broad application of our microsystem in aerosol monitoring for fighting the COVID-19 pandemic.

3.
Molecules ; 27(19)2022 Oct 08.
Article in English | MEDLINE | ID: covidwho-2066286

ABSTRACT

The COVID-19 pandemic is caused by SARS-CoV-2; the spike protein is a key structural protein that mediates infection of the host by SARS-CoV-2. In this study, we aimed to evaluate the effects of signal peptide on the secretion and release of SARS-CoV-2 spike protein. Therefore, we constructed a signal peptide deletion mutant and three signal peptide site-directed mutants. The (H) region and (C) region in the signal peptide of L5F-S13I mutant have changed significantly, compared with wild type, L5F and S13I. We demonstrated the effects of signal peptide on the secretion and synthesis of RBD protein, finding that mutation of S13 to I13 on the signal peptide is more conducive to the secretion of RBD protein, which was mainly due to the shift of the signal peptide cleavage site in the mutant S13I. Here, we not only investigated the structure of the N-terminal signal peptide of the SARS-CoV-2 spike protein but also considered possible secretory pathways. We suggest that the development of drugs that target the signal peptide of the SARS-CoV-2 spike protein may have potential to treat COVID-19 in the future.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Humans , Pandemics , Protein Sorting Signals/genetics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/metabolism
4.
Viruses ; 14(9)2022 09 13.
Article in English | MEDLINE | ID: covidwho-2033142

ABSTRACT

In the context of the COVID-19 pandemic, conducting antibody testing and vaccination is critical. In particular, the continued evolution of SARS-CoV-2 raises concerns about the effectiveness of vaccines currently in use and the activity of neutralizing antibodies. Here, we used the Escherichia coli expression system to obtain nine different SARS-CoV-2 RBD protein variants, including six single-point mutants, one double-point mutant, and two three-point mutants. Western blotting results show that nine mutants of the RBD protein had strong antigenic activity in vitro. The immunogenicity of all RBD proteins was detected in mice to screen for protein mutants with high immunogenicity. The results show that the mutants E484K, E484Q, K417T-E484K-N501Y, and K417N-E484K-N501Y, especially the former two, had better immunogenicity than the wild type. This suggests that site E484 has a significant impact on the function of the RBD protein. Our results demonstrate that recombinant RBD protein expressed in E. coli can be an effective tool for the development of antibody detection methods and vaccines.


Subject(s)
COVID-19 , Viral Vaccines , Amino Acids/genetics , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Viral , COVID-19/prevention & control , Escherichia coli/genetics , Humans , Mice , Mutant Proteins/genetics , Mutation , Neutralization Tests , Pandemics , Recombinant Proteins , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus
5.
Front Microbiol ; 13: 944078, 2022.
Article in English | MEDLINE | ID: covidwho-2009884

ABSTRACT

Invasive Staphylococcus aureus (S. aureus) infection is associated with high rates of mortality in children. No studies have been reported on invasive S. aureus infection among children in Kunming, China, and it remains unknown whether the COVID-19 epidemic has affected S. aureus prevalence in this region. Thus, this study investigated the changes in molecular characteristics and antimicrobial resistance of invasive S. aureus strains isolated from children in Kunming during 2019-2021. In total, 66 invasive S. aureus strains isolated from children were typed by multilocus sequence typing (MLST), spa, and Staphylococcal cassette chromosome mec (SCCmec), and antimicrobial resistance and virulence genes were analyzed. A total of 19 ST types, 31 spa types and 3 SCCmec types were identified. Thirty nine (59.09%) strains were methicillin-sensitive S. aureus (MSSA) and 27 (40.91%) strains were methicillin-resistant S. aureus (MRSA). The most common molecular type was ST22-t309 (22.73%, 15/66), followed by ST59-t437 (13.64%, 9/66). In 2019 and 2021, the dominant molecular type was ST22-t309, while in 2020, it was ST59-t437. After 2019, the dominant molecular type of MRSA changed from ST338-t437 to ST59-t437. All strains were susceptible to tigecycline, ciprofloxacin, moxifloxacin, vancomycin, quinopudine-dafoputin, linezolid, levofloxacin, and rifampicin. From 2019 to 2021, the resistance to penicillin and sulfamethoxazole initially decreased and then increased, a trend that contrasted with the observed resistance to oxacillin, cefoxitin, erythromycin, clindamycin, and tetracycline. Sixteen antimicrobial resistance profiles were identified, with penicillin-tetracycline-erythromycin-clindamycin-oxacillin-cefoxitin being the most common, and the antimicrobial resistance profiles varied by year. The carrier rates of virulence genes, icaA, icaD, hla, fnbA, fnbB, clfA, clfB, and cna were 100.00%. Furthermore, sak, pvl, icaC, icaR, fib, lip, hlb, hysA, sea, seb, and tsst-1 had carrier rates of 96.97, 92.42, 87.88, 69.70, 84.85, 62.12, 56.06, 50, 37.87, 30.30, and 7.58%, respectively. Since COVID-19 epidemic, the annual number of invasive S. aureus strains isolated from children in Kunming remained stable, but the molecular characteristics and antimicrobial resistance profiles of prevalent S. aureus strains have changed significantly. Thus, COVID-19 prevention and control should be supplemented by surveillance of common clinical pathogens, particularly vigilance against the prevalence of multidrug-resistant and high-virulence strains.

6.
Adv Sci (Weinh) ; 9(31): e2203565, 2022 11.
Article in English | MEDLINE | ID: covidwho-1999816

ABSTRACT

Wearing masks has been a recommended protective measure due to the risks of coronavirus disease 2019 (COVID-19) even in its coming endemic phase. Therefore, deploying a "smart mask" to monitor human physiological signals is highly beneficial for personal and public health. This work presents a smart mask integrating an ultrathin nanocomposite sponge structure-based soundwave sensor (≈400 µm), which allows the high sensitivity in a wide-bandwidth dynamic pressure range, i.e., capable of detecting various respiratory sounds of breathing, speaking, and coughing. Thirty-one subjects test the smart mask in recording their respiratory activities. Machine/deep learning methods, i.e., support vector machine and convolutional neural networks, are used to recognize these activities, which show average macro-recalls of ≈95% in both individual and generalized models. With rich high-frequency (≈4000 Hz) information recorded, the two-/tri-phase coughs can be mapped while speaking words can be identified, demonstrating that the smart mask can be applicable as a daily wearable Internet of Things (IoT) device for respiratory disease identification, voice interaction tool, etc. in the future. This work bridges the technological gap between ultra-lightweight but high-frequency response sensor material fabrication, signal transduction and processing, and machining/deep learning to demonstrate a wearable device for potential applications in continual health monitoring in daily life.


Subject(s)
COVID-19 , Nanocomposites , Wearable Electronic Devices , Humans , Monitoring, Physiologic , Machine Learning
7.
Chinese Journal of School Health ; 42(4):542-546, 2021.
Article in Chinese | CAB Abstracts | ID: covidwho-1502914

ABSTRACT

Objective: To understand knowledge, attitude and behavior toward Coronavirus disease 2019 (COVID-19) among middle school students in Wuhan, in the phase of normalized control and prevention of COVID-19, so as to provide evidence for further health education.

8.
J Breath Res ; 15(4)2021 10 22.
Article in English | MEDLINE | ID: covidwho-1462253

ABSTRACT

Rapid screening of COVID-19 is key to controlling the pandemic. However, current nucleic acid amplification involves lengthy procedures in addition to the discomfort of taking throat/nasal swabs. Here we describe potential breath-borne volatile organic compound (VOC) biomarkers together with machine learning that can be used for point-of-care screening of COVID-19. Using a commercial gas chromatograph-ion mobility spectrometer, higher levels of propanol were detected in the exhaled breath of COVID-19 patients (N= 74) and non-COVID-19 respiratory infections (RI) (N= 30) than those of non-COVID-19 controls (NC)/health care workers (HCW) (N= 87), and backgrounds (N= 87). In contrast, breath-borne acetone was found to be significantly lower for COVID-19 patients than other subjects. Twelve key endogenous VOC species using supervised machine learning models (support vector machines, gradient boosting machines (GBMs), and Random Forests) were shown to exhibit strong capabilities in discriminating COVID-19 from (HCW + NC) and RI with a precision ranging from 91% to 100%. GBM and Random Forests models can also discriminate RI patients from healthy subjects with a precision of 100%. In addition, the developed models using breath-borne VOCs could also detect a confirmed COVID-19 patient but with a false negative throat swab polymerase chain reaction test. It takes 10 min to allow an entire breath test to finish, including analysis of the 12 key VOC species. The developed technology provides a novel concept for non-invasive rapid point-of-care-test screening for COVID-19 in various scenarios.


Subject(s)
COVID-19 , Exhalation , Volatile Organic Compounds , Biomarkers , Breath Tests , Humans , Machine Learning , SARS-CoV-2
9.
J Aerosol Sci ; 152: 105693, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1392358

ABSTRACT

The COVID-19 pandemic has brought an unprecedented crisis to the global health sector. When discharging COVID-19 patients in accordance with throat or nasal swab protocols using RT-PCR, the potential risk of reintroducing the infection source to humans and the environment must be resolved. Here, 14 patients including 10 COVID-19 subjects were recruited; exhaled breath condensate (EBC), air samples and surface swabs were collected and analyzed for SARS-CoV-2 using reverse transcription-polymerase chain reaction (RT-PCR) in four hospitals with applied natural ventilation and disinfection practices in Wuhan. Here we discovered that 22.2% of COVID-19 patients (n = 9), who were ready for hospital discharge based on current guidelines, had SARS-CoV-2 in their exhaled breath (~105 RNA copies/m3). Although fewer surface swabs (3.1%, n = 318) tested positive, medical equipment such as face shield frequently contacted/used by healthcare workers and the work shift floor were contaminated by SARS-CoV-2 (3-8 viruses/cm2). Three of the air samples (n = 44) including those collected using a robot-assisted sampler were detected positive by a digital PCR with a concentration level of 9-219 viruses/m3. RT-PCR diagnosis using throat swab specimens had a failure rate of more than 22% in safely discharging COVID-19 patients who were otherwise still exhaling the SARS-CoV-2 by a rate of estimated ~1400 RNA copies per minute into the air. Direct surface contact might not represent a major transmission route, and lower positive rate of air sample (6.8%) was likely due to natural ventilation (1.6-3.3 m/s) and regular disinfection practices. While there is a critical need for strengthening hospital discharge standards in preventing re-emergence of COVID-19 spread, use of breath sample as a supplement specimen could further guard the hospital discharge to ensure the safety of the public and minimize the pandemic re-emergence risk.

10.
Clin Infect Dis ; 72(10): e652-e654, 2021 05 18.
Article in English | MEDLINE | ID: covidwho-1232192

ABSTRACT

Coronavirus disease 2019 (COVID-19) patients exhaled millions of severe acute respiratory syndrome coronavirus 2 RNA copies per hour, which plays an important role in COVID-19 transmission. Exhaled breath had a higher positive rate (26.9%, n = 52) than surface (5.4%, n = 242) and air (3.8%, n = 26) samples.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Respiratory System
11.
Ann Transl Med ; 9(8): 701, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1224388

ABSTRACT

BACKGROUND: The novel 2019 coronavirus (COVID-19) has caused a global pandemic, and often leads to extrapulmonary organ injury. However, the risk factors for extrapulmonary organ injury are still unclear. We aim to explore the risk factors for extrapulmonary organ injury and the association between extrapulmonary organ injury and the prognosis in COVID-19 patients. METHODS: We implemented a single-center, retrospective, observational study, in which a total of 349 confirmed COVID-19 patients admitted to Tongji Hospital from January 25, 2020, to February 25, 2020, were enrolled. We collected demographic, clinical, laboratory, and treatment data from electronic medical records. Potential risk factors for extrapulmonary organ injury of COVID-19 patients were analyzed by a multivariable binary logistic model, and multivariable Cox proportional hazards regression model was used for survival analysis in the patients with extrapulmonary organ injury. RESULTS: The average age of the included patients was 61.73±14.64 years. In the final logistic model, variables including aged 60 or older [odds ratio (OR) 1.826, 95% confidence interval (CI): 1.060-3.142], acute respiratory distress syndrome (ARDS) (OR 2.748, 95% CI: 1.051-7.185), lymphocytes count lower than 1.1×109/L (OR 0.478, 95% CI: 0.240-0.949), level of interleukin-6 (IL-6) greater than 7 pg/mL (OR 1.664, 95% CI: 1.005-2.751) and D-Dimer greater than 0.5 µg/mL (OR 2.190, 95% CI: 1.176-4.084) were significantly associated with the extrapulmonary organ injury. Kaplan-Meier curve and log-rank test showed that the probabilities of survival for patients with extrapulmonary organ injury were significantly lower than those without extrapulmonary organ injury. Multivariate Cox proportional hazards model showed that only myocardial injury (P=0.000, HR: 5.068, 95% CI: 2.728-9.417) and circulatory system injury (P=0.000, HR: 4.076, 95% CI: 2.216-7.498) were the independent factors associated with COVID-19 patients' poor prognosis. CONCLUSIONS: Older age, lymphocytopenia, high level of D-Dimer and IL-6, and the severity of lung injury were the high-risk factors of extrapulmonary organ injury in COVID-19 patients. Myocardial and circulatory system injury were the most important risk factors related to poor outcomes of COVID-19 patients. It may help clinicians to identify extrapulmonary organ injury early and initiate appropriate treatment.

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