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1.
Cytotherapy ; 24(5):S35-S35, 2022.
Article in English | EuropePMC | ID: covidwho-1812325

ABSTRACT

From SARS-CoV-1 outbreak in 2002 to the most recent SARS-CoV-2 pandemic (COVID-19), emergence of viral diseases has repeatedly threatened humanity over the recent decades. These viral diseases mainly cause respiratory symptoms, which can even lead to death when appropriate measures are not taken. In this study, we investigated whether adipose tissue-derived mesenchymal stem cell EVs (ASC-EVs) can attenuate acute lung injury (ALI) induced by H1N1 influenza A virus and SARS-CoV-2 and by what mechanism the ant-viral effect may occurs.

2.
American Journal of Transplantation ; 22(Supplement 3):638-639, 2022.
Article in English | EMBASE | ID: covidwho-2063546

ABSTRACT

Purpose: Solid organ transplant recipients (SOTR) develop weak antibody responses after SARS-CoV-2 vaccination. Published data on neutralizing activity of plasma, a better measure of protection, in SOTR following an additional dose of SARSCoV- 2 vaccine is limited. Method(s): Plasma was longitudinally collected from SOTR following initial COVID- 19 vaccination. Neutralizing activity against SARS-CoV-2 was assessed using the cPass Neutralization Antibody Detection Kit (GenScript, Biotech). ELISAs were performed against SARS-CoV-2 proteins (S1, N, RBD), CMV (glycoprotein B), Influenza A H1N1 (nucleoprotein), HSV-1, EBV glycoprotein (gp350), and tetanus toxoid for comparison. Result(s): Demographic and clinical characteristics are summarized in table 1. No participants had evidence of COVID-19 infection as IgG titers to SARS-CoV-2 N protein were low. Neutralizing activity against SARS-CoV-2 RBD was observed in 39.6% of individuals (N=21/53) ~93 days after initial vaccination. Participants with neutralizing activity were more likely to have received a liver transplant (47.6% vs 6.25%, p=0.001), and less likely to be on an anti-metabolite (52.4% vs. 87.5%, p=0.009) or triple immunosuppression (14.3% vs. 53.1%, p=0.008). After an additional vaccine dose, 78.1% (N=25/32) of participants developed neutralizing activity with significant increases in viral neutralization (figure 1, median 36.8% [95%CI 18.9-64.6] to 97.2% [95%CI 74.0-98.9], p<0.0001). Participants with low neutralizing activity demonstrated adequate antibody titers to other microbial antigens (figure 2). Conclusion(s): An additional dose of SARS-CoV-2 vaccine increased the number of SOTR with neutralizing activity and the magnitude of the seroresponse. SOTR with low neutralizing activity maintain humoral responses to other microbial antigens suggesting the diminished seroresponse might be related to inhibition of new B cell responses.

3.
Cytotherapy ; 24(5):S35, 2022.
Article in English | EMBASE | ID: covidwho-1996713

ABSTRACT

Background & Aim: From SARS-CoV-1 outbreak in 2002 to the most recent SARS-CoV-2 pandemic (COVID-19), emergence of viral diseases has repeatedly threatened humanity over the recent decades. These viral diseases mainly cause respiratory symptoms, which can even lead to death when appropriate measures are not taken. In this study, we investigated whether adipose tissue-derived mesenchymal stem cell EVs (ASC-EVs) can attenuate acute lung injury (ALI) induced by H1N1 influenza A virus and SARS-CoV-2 and by what mechanism the ant-viral effect may occurs. Methods, Results & Conclusion: EVs were isolated from ASC or HEK293T conditioned media by tangential flow filtration, and were characterized according to MISEV recommendation. Influenza A/ Puerto Rico/08/1934 (H1N1) and SARS-CoV-2 (NCCP43326) were used to model highly pathogenic human influenza A and SARS-CoV-2 virus infection, respectively, in mice and Syrian hamsters respectively. Treatment of ASC-EVs, from 0.15 x 109 to 5.0 x 109 particles/mL, showed inhibitory activities on cytopathic effects and replication of H1N1 and SARS-CoV-2 in MDCK cells and Vero E6 cells, respectively. In the mouse H1N1 influenza A virus induced acute lung injury (ALI) model, total of 4 daily injections of 1 x 1010 particles of ASC-EVs administration resulted in significantly increased survival rate by 30 – 40%, recovery of body weight, and improved clinical disease score from 9 dpi. In addition, ASC-EV treatment downregulated various inflammatory cytokines such as IL-1β, IL-6 and TNFα in lung tissue by up to 77%. In the Syrian hamster SARS-CoV-2 induced ALI model, total of 4 daily injections of ASC-EVs at a dose of 3 x 1010 or 1 x 1010 particles resulted recovery of body weights from 5 dpi, in a dose-dependent manner, by 9.7% - 12.75%. Further, ASC-EV treatment resulted in significant downregulation of viral genes and IL-1 beat in lung tissue. To elucidate the molecular mechanisms of the observed anti-viral effects of ASC-EVs, the role of multiple miRNAs and proteins present in the ASC-EVs were assessed in vitro. We identified one specific protein that conveyed anti-viral efficacy against the two studied viruses including SARS-CoV-2. Loss and gain of function studies revealed that this protein may be involved in the anti-viral efficacy of the ASC-EVs. Our findings support the concept that that ASC-EVs have anti-viral effects against virus induced ALI, which may have implications for the treatment of not only treatment COVID-19, but also future ALI-inducing virus diseases.

4.
Journal of Allergy and Clinical Immunology ; 149(2):AB59-AB59, 2022.
Article in English | Web of Science | ID: covidwho-1798141
5.
Atmosphere ; 12(9):14, 2021.
Article in English | Web of Science | ID: covidwho-1444087

ABSTRACT

This study aims to evaluate the accuracy and effectiveness of real-time personal monitoring of exposure to PM concentrations using low-cost sensors, in comparison to conventional data collection method based on fixed stations. PM2.5 data were measured every 5 min using a low-cost sensor attached to a bag carried by 47 asthmatic children living in the Seoul Metropolitan area between November 2019 and March 2020, along with the real-time GPS location, temperature, and humidity. The mobile sensor data were then matched with station-based hourly PM2.5 data using the time and location. Despite some uncertainty and inaccuracy of the sensor data, similar temporal patterns were found between the two sources of PM2.5 data on an aggregate level. However, average PM2.5 concentrations via personal monitoring tended to be lower than those from the fixed stations, particularly when the subjects were indoors, during nighttime, and located farther from the fixed station. On an individual level, a substantial discrepancy is observed between the two PM2.5 data sources while staying indoors. This study provides guidance to policymakers and researchers on improving the feasibility of personal monitoring via low-cost mobile sensors as an alternative or supplement to the conventional station-based monitoring.

6.
11th International Conference on Information and Communication Technology Convergence (ICTC) - Data, Network, and AI in the age of Untact (ICTC) ; : 753-755, 2020.
Article in English | Web of Science | ID: covidwho-1431670

ABSTRACT

In order to prevent the spread of infectious diseases such as COVID-19 in advance, a method of counting the number of people in the space is needed. However, when the camera is used for counting the number of people, privacy infringement may occur. This method requires an additional cost of installing the camera. With the use of internet of things (IoT) devices and the spread of smartphones, many Wi-Fi access points (APs) are installed. In this paper, we suggest a method to count the number of people in a space using theseWi-Fi APs. First, we show that the wireless channel changes depending on the person in the space. After that, we propose a way to count the number of people through machine learning using channel state information (CSI) of the Wi-Fi signal.

7.
12th ACM Conference on Bioinformatics, Computational Biology, and Health Informatics, BCB 2021 ; 2021.
Article in English | Scopus | ID: covidwho-1365247

ABSTRACT

We propose a novel privacy-preserving COVID-19 risk assessment algorithm that can make a fundamental contribution to the development of the next generation resilient public health and health care systems. The proposed algorithm, ShareTrace, uses a hyperlocal interaction graph to capture direct and indirect physical interactions among users. Combining user-reported symptoms that are propagated through the hyperlocal interaction graph via a novel message passing algorithm, ShareTrace is able to pick up early warning signals based on the combination of interactions with others and symptoms. The proposed algorithm is inspired by the belief propagation algorithm and iterative decoding of low-density parity-check codes over factor graphs. Our evaluation on synthetic data shows the efficiency and efficacy of the proposed solution. © 2021 ACM.

8.
Global Strategy Journal ; 2021.
Article in English | Scopus | ID: covidwho-1062102

ABSTRACT

Research Summary: Digitalization has three fundamental characteristics, reprogrammability infrastructural elementality, and intangibility. Based on these characteristics, it is transforming how firms organize for value creation, delivery, and capture. Its intangibility and infrastructural character largely free economic and business activities from the constraints of physical geography like those imposed by transportation and collocation. Digital communication technologies typically reinforce the centrifugal forces that favor dispersing the firm's high knowledge activities. Digital in situ technologies strengthen the centripetal forces toward concentrating the firm's low knowledge activities. Location dependence and product modularity are crucial moderators for tangible products, while institutional barriers are important for intangible ones. Finally, digital technologies increase the resilience of firms during disruptive events that impose restrictions on the movements of people and goods, as during the COVID-19 pandemic. Managerial Summary: Digitalization is a general purpose technology on the scale of the steam engine and electricity, and affects every aspect of business and society. It is transforming how firms organize for value creation, delivery, and capture. Freeing businesses from the constraints of transportation and collocation, it increases their resiliency in the face of global disruptions like those associated with the COVID-19 pandemic. Digital communication technologies typically reinforce the centrifugal forces that favor dispersing the firm's high knowledge activities. Digital in situ technologies like advanced robotics strengthen the centripetal forces toward concentrating the firm's low knowledge activities. Location dependence and product modularity are crucial moderators for tangible products, while institutional barriers are important for intangible ones. © 2021 Strategic Management Society

9.
Int. Conf. ICT Convergence ; 2020-October:753-755, 2020.
Article in English | Scopus | ID: covidwho-1026974

ABSTRACT

In order to prevent the spread of infectious diseases such as COVID-19 in advance, a method of counting the number of people in the space is needed. However, when the camera is used for counting the number of people, privacy infringement may occur. This method requires an additional cost of installing the camera. With the use of internet of things (IoT) devices and the spread of smartphones, many Wi-Fi access points (APs) are installed. In this paper, we suggest a method to count the number of people in a space using these Wi-Fi APs. First, we show that the wireless channel changes depending on the person in the space. After that, we propose a way to count the number of people through machine learning using channel state information (CSI) of the Wi-Fi signal. © 2020 IEEE.

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