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1.
Environ Int ; 166: 107369, 2022 Jun 22.
Article in English | MEDLINE | ID: covidwho-2305916

ABSTRACT

Particulate nitrate (pNO3) is now becoming the principal component of PM2.5 during severe winter haze episodes in many cities of China. To gain a comprehensive understanding of the key factors controlling pNO3 formation and driving its trends, we reviewed the recent pNO3 modeling studies which mainly focused on the formation mechanism and recent trends of pNO3 as well as its responses to emission controls in China. The results indicate that although recent chemical transport models (CTMs) can reasonably capture the spatial-temporal variations of pNO3, model-observation biases still exist due to large uncertainties in the parameterization of dinitrogen pentoxide (N2O5) uptake and ammonia (NH3) emissions, insufficient heterogeneous reaction mechanism, and the predicted low sulfate concentrations in current CTMs. The heterogeneous hydrolysis of N2O5 dominates nocturnal pNO3 formation, however, the contribution to total pNO3 varies among studies, ranging from 21.0% to 51.6%. Moreover, the continuously increasing PM2.5 pNO3 fraction in recent years is mainly due to the decreased sulfur dioxide emissions, the enhanced atmospheric oxidation capacity (AOC), and the weakened nitrate deposition. Reducing NH3 emissions is found to be the most effective control strategy for mitigating pNO3 pollution in China. This review suggests that more field measurements are needed to constrain the parameterization of heterogeneous N2O5 and nitrogen dioxide (NO2) uptake. Future studies are also needed to quantify the relationships of pNO3 to AOC, O3, NOx, and volatile organic compounds (VOCs) in different regions of China under different meteorological conditions. Research on multiple-pollutant control strategies involving NH3, NOX, and VOCs is required to mitigate pNO3 pollution, especially during severe winter haze events.

2.
Sci Rep ; 12(1): 21132, 2022 12 07.
Article in English | MEDLINE | ID: covidwho-2151070

ABSTRACT

International flights have accelerated the global spread of Coronavirus Disease 2019 (COVID-19). Determination of the optimal quarantine period for international travelers is crucial to prevent the local spread caused by imported COVID-19 cases. We performed a retrospective epidemiological study using 491 imported COVID-19 cases in Chengdu, China, to describe the characteristic of the cases and estimate the time from arrival to confirmation for international travelers using nonparametric survival methods. Among the 491 imported COVID-19 cases, 194 (39.5%) were asymptomatic infections. The mean age was 35.6 years (SD = 12.1 years) and 83.3% were men. The majority (74.1%) were screened positive for SARS-CoV-2, conducted by Chengdu Customs District, the People's Republic of China. Asymptomatic cases were younger than presymptomatic or symptomatic cases (P < 0.01). The daily number of imported COVID-19 cases displayed jagged changes. 95% of COVID-19 cases were confirmed by PT-PCR within 14 days (95% CI 13-15) after arriving in Chengdu. A 14-day quarantine measure can ensure non-infection among international travelers with a 95% probability. Policymakers may consider an extension of the quarantine period to minimize the negative consequences of the COVID-19 confinement and prevent the international spread of COVID-19. Nevertheless, the government should consider the balance between COVID-19 and socioeconomic development, which may cause more serious social and health crises.


Subject(s)
COVID-19 , Humans , Adult , COVID-19/epidemiology , COVID-19/prevention & control , Retrospective Studies , SARS-CoV-2 , Government , China/epidemiology
3.
Biomed Signal Process Control ; 81: 104487, 2023 Mar.
Article in English | MEDLINE | ID: covidwho-2149419

ABSTRACT

Blood Oxygen ( SpO 2 ), a key indicator of respiratory function, has received increasing attention during the COVID-19 pandemic. Clinical results show that patients with COVID-19 likely have distinct lower SpO 2 before the onset of significant symptoms. Aiming at the shortcomings of current methods for monitoring SpO 2 by face videos, this paper proposes a novel multi-model fusion method based on deep learning for SpO 2 estimation. The method includes the feature extraction network named Residuals and Coordinate Attention (RCA) and the multi-model fusion SpO 2 estimation module. The RCA network uses the residual block cascade and coordinate attention mechanism to focus on the correlation between feature channels and the location information of feature space. The multi-model fusion module includes the Color Channel Model (CCM) and the Network-Based Model(NBM). To fully use the color feature information in face videos, an image generator is constructed in the CCM to calculate SpO 2 by reconstructing the red and blue channel signals. Besides, to reduce the disturbance of other physiological signals, a novel two-part loss function is designed in the NBM. Given the complementarity of the features and models that CCM and NBM focus on, a Multi-Model Fusion Model(MMFM) is constructed. The experimental results on the PURE and VIPL-HR datasets show that three models meet the clinical requirement(the mean absolute error ⩽ 2%) and demonstrate that the multi-model fusion can fully exploit the SpO 2 features of face videos and improve the SpO 2 estimation performance. Our research achievements will facilitate applications in remote medicine and home health.

4.
Antiviral Res ; 208: 105450, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2085916

ABSTRACT

FB2001 is a drug candidate that targets the main protease of SARS-CoV-2 via covalently binding to cysteine 145. In this study, we evaluated the inhibitory activities of FB2001 against several SARS-CoV-2 variants in vitro and in vivo (in mice), and we also evaluated the histopathological analysis and immunostaining of FB2001 on lung and brain which have been rarely reported. The results showed that FB2001 exhibited potent antiviral efficacy against several current SARS-CoV-2 variants in Vero E6 cells, namely, B.1.1.7 (Alpha): EC50 = 0.39 ± 0.01 µM, EC90 = 0.75 ± 0.01 µM; B.1.351 (Beta): EC50 = 0.28 ± 0.11 µM, EC90 = 0.57 ± 0.21 µM; B.1.617.2 (Delta): EC50 = 0.27 ± 0.05 µM, EC90 = 0.81 ± 0.20 µM; B.1.1.529 (Omicron): EC50 = 0.26 ± 0.06 µM and EC50 = 0.042 ± 0.007 µM (in the presence of a P-glycoprotein inhibitor). FB2001 remained potent against SARS-CoV-2 replication in the presence of high concentrations of human serum, which indicating that human serum had no significant effect on the in vitro inhibitory activity. Additionally, this inhibitor exhibited an additive effect against SARS-CoV-2 when combined with Remdesivir. Furthermore, FB2001 significantly reduced the SARS-CoV-2 copy numbers and titers in the lungs and brains in vivo, and alleviated the pathological symptoms. In addition, FB2001 could alleviated local bleeding, erythrocyte overflow, edema, and inflammatory cell infiltration in brain tissue, and inhibitors reducing viral titers and improving inflammation in the brain have been rarely reported. A physiologically based pharmacokinetic model was established and verified to predict the FB2001 concentration in human lungs. When FB2001 was administered at 200 mg twice a day for 5 days, the observed Ctrough ss in plasma and predicted Ctrough ss of lung total concentration were 0.163 and 2.5 µg/mL, which were approximately 9 and 132-fold higher than the EC50 of 0.019 µg/mL (0.042 µM) against Omicron variant. Taken together, our study suggests that FB2001 is a promising therapeutic agent in COVID-19 treatment and can be combined with remdesivir to achieve improved clinical outcomes. Owing to its good safety and tolerability in healthy human (NCT05197179 and NCT04766931), FB2001 has been approved for Phase II/III clinical trial (NCT05445934).


Subject(s)
COVID-19 Drug Treatment , Coronavirus Infections , Pneumonia, Viral , Animals , Humans , Mice , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Betacoronavirus , Coronavirus Infections/drug therapy , Pandemics , Pneumonia, Viral/drug therapy , Protease Inhibitors/pharmacology , Protease Inhibitors/therapeutic use , SARS-CoV-2 , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as Topic
5.
Front Immunol ; 13: 882919, 2022.
Article in English | MEDLINE | ID: covidwho-2039673

ABSTRACT

Given that vaccine-induced adverse effects were mostly based on previous laboratory research and clinical trials, real-world data on the safety of coronavirus disease 2019 (COVID-19) vaccination were lacking. This study reported the adverse events (AEs) among inactivated COVID-19 vaccine recipients. Data were collected from a total of 2,808 hospital employees and their family members in Wuhan, China, with all of them receiving the first dose of inactivated COVID-19 vaccines from two pharmaceutical companies. The first dose was given between 29th April and 13th May 2021. A total of 2,732 vaccinees received the second dose between 27th May and 8th July 2021. The whole process of receiving the vaccine was monitored by clinical pharmacists, and the information on AEs including demographics, occurrence, types, and severity was recorded through an online questionnaire and telephone follow-up. Most of the common AEs were mild and tolerable, and the overall incidence of AEs was lower than the data from the safety profile in clinical trials. Moreover, the incidence of AEs in the first dose (21.30%, 598) was higher than that in the second dose (16.07%, 439). Furthermore, the first injection had more severe AEs (4, 0.14%) than the second injection (2, 0.07%). The AEs involved the skin, muscle, respiratory tract, gastrointestinal tract, cardiovascular system, and other tissues and systems. The most common AE was pain at the injection site (first dose: 10.19%, second dose: 12.55%). All the vaccinees with AEs for both doses recovered fully in the end. It was noted that some AEs might cause blood coagulation disorder and bleeding risk. Therefore, ongoing monitoring of AEs after COVID-19 vaccination is essential in evaluating the benefits and risks of each vaccine.


Subject(s)
COVID-19 , Vaccines , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Humans , Pharmaceutical Preparations , Pharmacists
6.
J Environ Manage ; 318: 115618, 2022 Sep 15.
Article in English | MEDLINE | ID: covidwho-1914593

ABSTRACT

We adopted a network approach to examine the dependence between green bonds and financial markets. We first created a static dependency network for a given set of variables using partial correlations. Secondly, to evaluate the centrality of the variables, we illustrated with-in system connections in a minimum spanning tree (MST). Afterward, rolling-window estimations are applied in both dependency and centrality networks for indicating time variations. Using the data spanning January 3, 2011 to October 30, 2020, we found that green bonds and commodity index had positive dependence on other financial markets and are system-wide net contributors before and after COVID-19. Time-varying dynamics illustrated heightened system integration, particularly during the crisis periods. The centrality networks reiterated the leading role of green bonds and commodity index pre- and post-COVID. Finally, rolling window analysis ascertained system dependence, centrality, and dynamic networks between green bonds and financial markets where green bond sustained their positive dependence all over the sample period. Green bonds' persistent dependence and centrality enticed several implications for policymakers, regulators, investors, and financial market participants.


Subject(s)
COVID-19 , Humans
7.
Atmospheric Chemistry and Physics ; 22(8):5495-5514, 2022.
Article in English | ProQuest Central | ID: covidwho-1811067

ABSTRACT

PM2.5, generated via both direct emission and secondary formation, can have varying environmental impacts due to different physical and chemical properties of its components. However, traditional methods to quantify different PM2.5 components are often based on online or offline observations and numerical models, which are generally high economic cost- or labor-intensive. In this study, we develop a new method, named Multi-Tracer Estimation Algorithm (MTEA), to identify the primary and secondary components from routine observation of PM2.5. By comparing with long-term and short-term measurements of aerosol chemical components in China and the United States, it is proven that MTEA can successfully capture the magnitude and variation of the primary PM2.5 (PPM) and secondary PM2.5 (SPM). Applying MTEA to the China National Air Quality Network, we find that (1) SPM accounted for 63.5 % of the PM2.5 in cities in southern China on average during 2014–2018, while the proportion dropped to 57.1 % in the north of China, and at the same time the secondary proportion in regional background regions was ∼ 19 % higher than that in populous regions;(2) the summertime secondary PM2.5 proportion presented a slight but consistent increasing trend (from 58.5 % to 59.2 %) in most populous cities, mainly because of the recent increase in O3 pollution in China;(3) the secondary PM2.5 proportion in Beijing significantly increased by 34 % during the COVID-19 lockdown, which might be the main reason for the observed unexpected PM pollution in this special period;and finally, (4) SPM and O3 showed similar positive correlations in the Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions, but the correlations between total PM2.5 and O3 in these two regions, as determined from PPM levels, were quite different. In general, MTEA is a promising tool for efficiently estimating PPM and SPM, and has huge potential for future PM mitigation.

8.
BMJ Open ; 12(3): e055880, 2022 03 24.
Article in English | MEDLINE | ID: covidwho-1765125

ABSTRACT

IntroductionSilent cerebrovascular disease (SCD), which is a common disease in the elderly, leads to cognitive decline, gait disorders, depression and urination dysfunction, and increases the risk of cerebrovascular events. Our study aims to compare the accuracy of the diagnosis of SCD-related gait disorders between the intelligent system and the clinician. Our team have developed an intelligent evaluation system for gait. This study will evaluate whether the intelligent system can help doctors make clinical decisions and predictions, which aids the early prevention and treatment of SCD. METHODS AND ANALYSIS: This study is a multi-centred, prospective, randomised and controlled trial.SCD subjects aged 60-85 years in Shanghai and Guizhou will be recruited continuously. All subjects will randomly be divided into a doctor with intelligence assistance group or a doctor group, at a 1:1 ratio. The doctor and intelligent assistant group will accept the intelligent system evaluation. The intelligent system obtains gait parameters by an Red-Green-Blue-depth camera and computer vision algorithm. The doctor group will accept the clinicians' routine treatment procedures. Meanwhile, all subjects will accept the panel's gait assessment and recognition rating scale as the gold standard. The primary outcome is the sensitivity of the intelligent system and clinicians to screen for gait disorders. The secondary outcomes include the healthcare costs and the incremental cost effectiveness ratio of intelligent systems and clinicians to screen for gait disorders. ETHICS AND DISSEMINATION: Approval was granted by the Ethics Committee of Zhongshan Hospital affiliated with Fudan University on 26 November 2019. The approval number is B2019-027(2) R. All subjects will sign an informed consent form before enrolment. Serious adverse events will be reported to the main researchers and ethics committees. The subjects' data will be kept strictly confidential. The results will be disseminated in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04457908.


Subject(s)
Cerebrovascular Disorders , Gait , Aged , Cerebrovascular Disorders/diagnosis , China , Cost-Benefit Analysis , Humans , Multicenter Studies as Topic , Prospective Studies , Randomized Controlled Trials as Topic
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.
Disease Surveillance ; 36(6):587-592, 2021.
Article in Chinese | CAB Abstracts | ID: covidwho-1395020

ABSTRACT

Objective: To understand the epidemiological characteristics of imported coronavirus disease 2019 (COVID-19) cases detected in Chengdu, Sichuan, and provide scientific basis for the prevention and control of COVID-19.

11.
Environ Sci Technol ; 55(17): 11557-11567, 2021 Sep 07.
Article in English | MEDLINE | ID: covidwho-1371582

ABSTRACT

The lockdown due to COVID-19 created a rare opportunity to examine the nonlinear responses of secondary aerosols, which are formed through atmospheric oxidation of gaseous precursors, to intensive precursor emission reductions. Based on unique observational data sets from six supersites in eastern China during 2019-2021, we found that the lockdown caused considerable decreases (32-61%) in different secondary aerosol components in the study region because of similar-degree precursor reductions. However, due to insufficient combustion-related volatile organic compound (VOC) reduction, odd oxygen (Ox = O3 + NO2) concentration, an indicator of the extent of photochemical processing, showed little change and did not promote more decreases in secondary aerosols. We also found that the Chinese provinces and international cities that experienced reduced Ox during the lockdown usually gained a greater simultaneous PM2.5 decrease than other provinces and cities with an increased Ox. Therefore, we argue that strict VOC control in winter, which has been largely ignored so far, is critical in future policies to mitigate winter haze more efficiently by reducing Ox simultaneously.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Aerosols/analysis , Air Pollutants/analysis , Air Pollution/analysis , Air Pollution/prevention & control , China , Communicable Disease Control , Environmental Monitoring , Humans , Oxygen , Particulate Matter/analysis , SARS-CoV-2
12.
Int J Ophthalmol ; 14(8): 1133-1137, 2021.
Article in English | MEDLINE | ID: covidwho-1342055

ABSTRACT

AIM: To explore the ocular features of corona virus disease (COVID)-19 and severe acute respiratory syndrome coronavirus (SARS-CoV)-2 detection in tears and conjunctival scrapes in non-severe COVID-19 patients. METHODS: This is a multicenter observational clinical study with no intervention conducted from Jan 25th to March 1st, 2020. Clinical data and samples of tears and conjunctival scraping were collected in consecutive laboratory-confirmed, non-severe COVID-19 patients from three hospitals. COVID-19 virus was analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) kits. RESULTS: Totally 255 laboratory-confirmed, non-severe COVID-19 patients were recruited for ocular manifestation investigation. Of them, 54.9% were females, with a mean age of 49.4y. None of the patients has evidence of uveitis; 11 patients (4.3%) complained of mild asthenopia; 2 (0.8%) had mild conjunctival congestion and serous secretion. Twenty-five of them had performed tears and conjunctival scrape for COVID-19 virus detection, with 4 yield possible positive results in the nucleoprotein gene. One of them were asymptomatic with normal chest CT and positive pharyngeal swab result. CONCLUSION: Ocular manifestations are neither common nor specific in non-severe COVID-19 patients. Meanwhile, COVID-19 virus nucleotides can be detected in the tears and conjunctival scrape samples, warranting further research on the transmissibility by the ocular route.

13.
Geophys Res Lett ; 48(8): e2020GL091591, 2021 Apr 28.
Article in English | MEDLINE | ID: covidwho-1124648

ABSTRACT

During the COVID-19 lockdown in 2020, large-scale industrial and transportation emissions were reduced, but high PM2.5 concentration still occurred. This study investigated the variation of particle number size distribution during the lockdown, and analyzed the characteristics of new particle formation (NPF) events and its potential impact on haze formation. Through measurement conducted in urban Beijing during the first 3 months of 2020, and comparison with year-over-year data, the decrease of primary Aitken-mode particles was observed. However, frequencies, formation rates and growth rates of NPF events remained stable between 2020 and 2019 in the same period. As a result, >25 nm particles produced by NPF events, would play a more important role in serving as the haze formation "seeds" compared to those produced by primary emissions. This finding emphasizes the significance on the understanding of NPF mechanisms when making pollution mitigation policy in the future.

14.
Macau Journal of Nursing ; 19(2):25-29, 2020.
Article in Chinese | CINAHL | ID: covidwho-994110

ABSTRACT

Patients with advanced kidney disease are more susceptible to Novel Coronavirus Pneumonia (NPC) infection than other people because of the detrimental immune system with the patients. It is important for health professionals to protect the patients with advanced kidney disease in their daily services. This article describes preventive strategies taken by health professionals in the kidney ward in a hospital in Mianyang, Sichuan, China, including establishment of an executive team, development of dialysis procedures, investigation of admitted patients epidemiology history related to NCP, and training of health professionals. Thanks to the implementation of these measures, together with the overall success of control in Mianyang, no NCP infections were detected among the patients in the ward. While these measures might have been affective during NCP epidemic, they may also be effective to control hospital-associated infections in other circumstances.

15.
Front Psychol ; 11: 582436, 2020.
Article in English | MEDLINE | ID: covidwho-971101

ABSTRACT

INTRODUCTION: During the COVID-19 outbreak, many citizens were asked to stay at home in self-quarantine, which can pose a significant challenge with respect to remaining physically active and maintaining mental health. This study aimed to evaluate the prevalence of inadequate physical activity, anxiety, and depression and to explore the relationship of physical activity with anxiety and depression symptoms among Chinese college students during quarantine. METHOD: Using a web-based cross-sectional survey, we collected data from 1,396 Chinese college students. Anxiety and depression were assessed with the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS), respectively. The data on physical activity were collected by types of physical activity and the International Physical Activity Questionnaire (IPAQ-SF). RESULTS: During the COVID-19 outbreak, about 52.3% of Chinese college students had inadequate physical activity. The rates of anxiety and depression symptoms were 31.0 and 41.8%, respectively. A high level of physical activity (ß = -0.121, P < 0.001) was significantly closely associated with low anxiety, while a moderate (ß = -0.095, P = 0.001), or high (ß = -0.179, P < 0.001) level of physical activity was significantly closely associated with reduced depression after adjusting confounding demographic factors. Moreover, specific types of physical activity, such as stretching and resistance training, were negatively correlated with both anxiety and depression; doing household chores was negatively correlated with depression. CONCLUSION: Our findings highlight specific levels and types of home-based physical activities that need to be taken into consideration to protect the mental health of college students during the COVID-19 epidemic.

16.
Int J Clin Exp Pathol ; 13(11): 2753-2757, 2020.
Article in English | MEDLINE | ID: covidwho-962127

ABSTRACT

The outbreak of the acute respiratory syndrome coronavirus 2 has spread around the world and poses a challenge to clinical frontline nursing staff. In the early stage of the epidemic, our hospital responded promptly and added pertinent prevention measures on the basis of the existing fever clinic (FC) to ensure zero infection of medical staff and patients. The experience of the fever screening site establishment, epidemiologic investigation procedure amelioration, and integrated fever management will be introduced in the communication.

17.
Clin Transl Immunology ; 9(9): e1182, 2020.
Article in English | MEDLINE | ID: covidwho-796073

ABSTRACT

OBJECTIVES: Asymptomatic and symptomatic patients may transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but their clinical features and immune responses remain largely unclear. We aimed to characterise the clinical features and immune responses of asymptomatic and symptomatic patients infected with SARS-CoV-2. METHODS: We collected clinical, laboratory and epidemiological records of patients hospitalised in a coronavirus field hospital in Wuhan. We performed qualitative detection of anti-SARS-CoV-2 immunoglobulin M (IgM) and immunoglobulin G (IgG) using archived blood samples. RESULTS: Of 214 patients with SARS-CoV-2, 26 (12%) were asymptomatic at hospital admission and during hospitalisation. Most asymptomatic patients were ≤ 60 years (96%) and females (65%) and had few comorbidities (< 16%). Serum levels of white and red blood cells were higher in asymptomatic than in symptomatic patients (P-values < 0.05). During hospitalisation, IgG seroconversion was commonly observed in both asymptomatic and symptomatic patients (85% versus 94%, P-value = 0.07); in contrast, IgM seroconversion was less common in asymptomatic than in symptomatic patients (31% versus 74%, P-value < 0.001). The median time from the first virus-positive screening to IgG or IgM seroconversion was significantly shorter in asymptomatic than in symptomatic patients (median: 7 versus 14 days, P-value < 0.01). Furthermore, IgG/IgM seroconversion rates increased concomitantly with the clearance of SARS-CoV-2 in both asymptomatic and symptomatic patients. At the time of virus clearance, IgG/IgM titres and plasma neutralisation capacity were significantly lower in recovered asymptomatic than in recovered symptomatic patients (P-values < 0.01). CONCLUSION: Asymptomatic and symptomatic patients exhibited different kinetics of IgG/IgM responses to SARS-CoV-2. Asymptomatic patients may transmit SARS-CoV-2, highlighting the importance of early diagnosis and treatment.

18.
Financ Res Lett ; 40: 101743, 2021 May.
Article in English | MEDLINE | ID: covidwho-733850

ABSTRACT

This paper investigates the risk spillover between China's crude oil futures and international crude oil futures by constructing upside and downside VaR connectedness networks. The findings show that China's crude oil futures behave as a net risk receiver in the global crude oil system, in which Brent and WTI play the leading roles in risk transmission in the system. The dynamic results indicate that the risk spillover between Chinese and international crude oil futures presents obvious time-varying characteristics and has risen sharply since the beginning of 2020, induced by the COVID-19 pandemic.

19.
Financ Res Lett ; 36: 101528, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-728553

ABSTRACT

The rapid spread of coronavirus (COVID-19) has dramatic impacts on financial markets all over the world. It has created an unprecedented level of risk, causing investors to suffer significant loses in a very short period of time. This paper aims to map the general patterns of country-specific risks and systemic risks in the global financial markets. It also analyses the potential consequence of policy interventions, such as the US' decision to implement a zero-percent interest rate and unlimited quantitative easing (QE), and to what extent these policies may introduce further uncertainties into global financial markets.

20.
Medicine (Baltimore) ; 99(31): e21429, 2020 Jul 31.
Article in English | MEDLINE | ID: covidwho-696106

ABSTRACT

RATIONALE: The COVID-19 cases increased very fast in January and February 2020. The mortality among critically ill patients, especially the elder ones, is relatively high. Considering many patients died of severe inflammation response, it is urgent to develop effective therapeutic strategies for these patients. The human umbilical cord mesenchymal stem cells (hUCMSCs) have shown good capabilities to modulate the immune response and repair the injured tissue. Therefore, investigating the potential of hUCMSCs to the treatment of COVID-19 critically ill patients is necessary. PATIENT CONCERNS: A 65-year-old woman felt fatigued and had a fever with body temperature of 38.2C, coughed up white foaming sputum. After 1 day, she had chest tightness with SPO2 of 81%, and blood pressure of 160/91 mm Hg. DIAGNOSE: According to the guideline for the diagnosis and treatment of 2019 novel coronavirus infected pneumonia (Trial 4th Edition), COVID-19 was diagnosed, based on the real-time RT-PCR test of SARS-CoV-2. INTERVENTIONS: After regular treatment for 12 days, the inflammation symptom of the patient was still very severe and the potential side effects of corticosteroid were observed. Then, allogenic hUCMSCs were given 3 times (5 × 10 cells each time) with a 3-day interval, together with thymosin α1 and antibiotics daily injection. OUTCOMES: After these treatments, most of the laboratory indexes and CT images showed remission of the inflammation symptom. The patient was subsequently transferred out of ICU, and the throat swabs test reported negative 4 days later. LESSONS: These results indicated the clinical outcome and good tolerance of allogenic hUCMSCs transfer.


Subject(s)
Betacoronavirus , Cord Blood Stem Cell Transplantation/methods , Coronavirus Infections/therapy , Mesenchymal Stem Cell Transplantation/methods , Pneumonia, Viral/therapy , Aged , Anti-Bacterial Agents/therapeutic use , COVID-19 , Combined Modality Therapy , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Female , Humans , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Thymalfasin/therapeutic use , Treatment Outcome , COVID-19 Drug Treatment
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