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This study analyzed the relationship of physical activity levels with walking ability and fall-related fitness in older adults in the Henan Provence, China. Physical activity levels of 288 older adults were assessed using the short form of the International Physical Activity Questionnaire. The participants were divided into low (LPAG, n = 81), moderate (MPAG, n = 106), and high physical activity groups (HPAG, n = 101). The 10-m walking test (10MWT), 3-m backward walking (3MBW), and Berg Balance Scale (BBS) were used to evaluate walking ability. Thirty seconds Sit to Stand Test (30SST), Time up and Go Test (TUGT), and figure-of-8 walk test (8WT) were evaluated for fall-related fitness. One-way ANOVA was used to detect between group differences, whilst Pearson's correlation was used to evaluate the relationship between total physical activity level and the measured variables. Logistic regression analyses were used to compute the odds ratios (ORs) of LPAG and MPAG relative to HPAG. There were significant differences between the groups for walking ability, 10MWT (p < 0.01), 3MBW, and BBS (p < 0.01), and also for variables of fall-related fitness, TUGT (p < 0.01), and 8WT (p < 0.01). Total physical activity levels had significant correlations with all variables except 30SST. In the walking ability, OR for 10MWT was 2.42 and 2.53 times for the LPAG compared to that for HPAG by model 1 and model 2. OR for BBS was 3.24 and 3.54 times for the LPAG and 9.31 and 9.65 times for the MPAG compared to for the HPAG by model 1 and model 2. In the fall-related fitness, OR for 8WT was 14.09 and 16.76 times for the LPAG compared to that for HPAG. High levels of physical activity are positively correlated with good walking ability and fall-related fitness. Increasing physical activity levels can reduce the risks associated with impaired walking ability and fall-related fitness.Copyright ©2023 The Author(s). Published by MRE Press.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the outbreak of pneumonia which originated in Wuhan, China, at the end of 2019 has turned into a global pandemic—now termed coronavirus diseases 2019 (COVID-19). Like previously reported SARS-CoV strains, the newly discovered SARS-CoV-2 was also found to initiate the pathogenesis by binding with the angiotensin-converting enzyme 2 (ACE2), a receptor produced by various organs in the human body. Hence, COVID-19 is a viral multisystem disease which particularly infects the vascular system expressing ACE2 and reduced the ACE2 function;this further complexed by organ-specific pathogenesis related to the damage of cells expressing ACE2, such as alveolus, glomerulus, endothelium, and cardiac microvasculature. Under these conditions, it was advocated that the upregulation of ACE2 expression in predisposing individuals with aberrant renin–angiotensin system (RAS) level to advanced viral load on infection and relatively a greater number of cell death. Recently, a significant role of decreased ACE2 production and inequality between the RAS and ACE2/angiotensin-(1–7)/ MAS (mitochondrial Ang system) after the onset of SARS-CoV-2 infection was established as a key factor for multiple organ injury in SARS-CoV-2-infected individuals. Furthermore, restoration of this imbalance has been suggested as a therapeutic approach to attenuate organ injuries in SARS-CoV-2 infection. Based on available data, this chapter presents the updated mechanism of the multi-organ diseases causes by COVID-19 via ACE2 which can be further helpful in the development of specific therapeutics. © The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. 2021.
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Background: Immunocompromised patients with COVID-19 tend to shed viable virus for a prolonged period. Therefore, for moderately or severely immunocompromised patients with COVID-19, CDC recommends an isolation period of at least 20 days and ending isolation in conjunction with serial testing and consultation with an infectious disease specialist. However, data on viral kinetics and risk factors for prolonged viral shedding in these patients are limited. Method(s): From February 1, 2022 to April 1, 2022, we collected weekly saliva samples from immunocompromised patients with COVID-19 admitted to a tertiary hospital in Seoul, South Korea. Genomic and subgenomic RNAs were measured, and virus culture was performed. Result(s): A total of 41 patients were enrolled;29 (70%) were receiving chemotherapy against hematologic malignancies and the remaining 12 (30%) had undergone solid organ transplantation. Of the 41 patients, 14 (34%) had received 3 doses or more of COVID-19 vaccines. Real-time RT-PCR revealed that 7 (17%) were infected with Omicron BA.1, and 33 (80%) with Omicron BA.2. The median duration of viable virus shedding was 4 weeks (IQR 3-6). Patients undergoing B-cell depleting therapy shed viable virus for longer than the comparator (p=0.01). Multivariable analysis showed that 3-dose or more vaccination (HR 0.33, 95% CI 0.12 - 0.93, p = 0.04) and B-cell depleting therapy (HR 12.50, 95% CI 2.44 - 100.00, p = 0.003) independently affected viable virus shedding of SARS-CoV-2. Conclusion(s): Immunocompromised patients with COVID-19 shed viable virus for median 4 weeks. B-cell depleting therapy increases the risk of prolonged viable viral shedding, while completion of a primary vaccine series reduces this risk. Overall distribution of samples according to genomic viral copy number and culture positivity. Red dot indicates positive culture results, whereas blue dot indicated negative culture results. (Figure Presented).
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Introduction/Aim: The interferon gamma release assay (IGRA), used in diagnosing latent tuberculosis infections (LTBI), relies on the release of interferon gamma from T-cells exposed to M. tuberculosis specific peptides. An 'indeterminate' IGRA result is most commonly due an inadequate control (or 'mitogen') response, which may reflect underlying T-cell dysfunction, that is potentially associated with markers of severity in patients with COVID-19. The aim of this study was to determine associations and predictors of an indeterminate IGRA in hospitalised patients with COVID-19. Method(s): We performed a single centre, retrospective study on COVID-19 patients admitted to a tertiary referral hospital who had IGRA testing performed over a 5 months period. Demographics, markers of COVID-19 severity and other parameters were recorded, along with outcomes of COVID-19 infection. The primary outcomes included predictors of indeterminate IGRA results and associations with COVID-19 outcomes (severity, length of stay and mortality). Result(s): A total of 181 patients were included for analysis. Outcomes of IGRA testing included negative (n = 117) and indeterminate (n = 60) results. Patients with a positive IGRA (n = 4) were excluded from analysis. The odds of an indeterminate IGRA were increased with a higher severity grade of COVID-19 (OR 2.5;95% CI 1.3-4.9), immunosuppression at baseline (OR 2.3;95% CI 1.1-4.7) and when IGRA testing was done after immunosuppression for COVID-19 was commenced (OR 1.4;95% CI 1.1-1.8). A longer length of stay was more likely with an indeterminate IGRA compared to a negative result (OR 1.08;95% CI 1.03-1.14), No difference in mortality between the two IGRA subgroups was found. Conclusion(s): Our study demonstrates an indeterminate IGRA was associated with markers of disease severity and immunosuppression. In this cohort an indeterminate result was also associated with worse COVID-19 outcomes in hospitalised patients. This result could potentially be used as a prognostic marker for patients admitted with COVID-19.
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This article investigates the determinants of Bitcoin returns. The authors consider a comprehensive set of information variables under five categories: macroeconomics, blockchain technology, other assets, stress level, and investor sentiment. Their approach toward this large dataset is built upon dimension-reduction models such as Backward Elimination, least absolute shrinkage and selection operator (LASSO), principal component regression (PCR), and three-pass regression filter (3PRF). The empirical results show that blockchain technology, stress level, and investor sentiment have positive, negative, and positive predicting power on Bitcoin returns, respectively. Macroeconomic variables exhibit insignificant impacts on Bitcoin returns. Other asset variables show little predicting power until 2019, but some become a significant predictor during the COVID-19 pandemic. Overall, the authors caution against using Bitcoin as a risk-hedging device in financial portfolios. They also find that, consistent with other financial assets such as equities, Bitcoin shows increased predictability with a longer return horizon. Due to their empirical results, they also advocate the use of 3PRF;relative to other dimension-reduction methods under consideration, they observe superior performance of 3PRF in predicting both the level and the direction of future Bitcoin returns across all return horizons.
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Purpose: This study aims to examine the multiscale predictability power of COVID-19 deaths and confirmed cases on the S&P 500 index (USA), CAC30 index (France), BSE index (India), two strategic commodity futures (West Texas intermediate [WTI] crude oil and Gold) and five main uncertainty indices Equity Market Volatility Ticker (EMV), CBOE Volatility Index (VIX), US Economic Policy Uncertainty (EPU), CBOE Crude Oil Volatility Index (OVX) and CBOE ETF Gold Volatility Index (GVZ). Furthermore, the authors analyze the impact of uncertainty indices and COVID-19 deaths and confirmed cases on the price returns of stocks (S&P500, CAC300 and BSE), crude oil and gold. Design/methodology/approach: The authors used the wavelet coherency method and quantile regression approach to achieve the objectives. Findings: The results show strong multiscale comovements between the variables under investigation. Lead-lag relationships vary across frequencies. Finally, COVID-19 news is a powerful predictor of the uncertainty indices at intermediate (4–16 days) and low (32–64 days) frequencies for EPU and at low frequency for EMV, VIX, OVX and GVZ indices from January to April 2020. The S&P500, CAC30 and BSE indexes and gold prices comove with COVID-19 news at low frequencies during the sample period. By contrast, COVID-19 news and WTI oil moderately correlated at low frequencies. Finally, the returns on equity and commodity assets are influenced by uncertainty indices and are sensitive to market conditions. Originality/value: This study contributes to the literature by exploring the time and frequency dependence between COVID-19 news (confirmed and death cases) on the returns of financial and commodity markets and uncertainty indexes. The findings can assist market participants and policymakers in considering the predictability of future prices and uncertainty over time and across frequencies when setting up regulations that aim to enhance market efficiency. © 2023, Emerald Publishing Limited.
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This paper examines the dynamic spillover interconnectedness of G7 Real Estate Investment Trusts (REITs) markets. We use the spillover index of Diebold and Yilmaz (2012), the time-varying parameters vector-autoregression (TVP-VAR) model, and the quantile regression approach. The result show that REITs network connectedness is dynamic and experiences an abrupt increase in the first wave of COVID-19 outbreak (2020Q1). We also observe a substantial abrupt decrease in connectedness during the success of vaccination programs (end 2021). The connectedness among assets is much stronger during COVID-19 than before. The REITs of Japan and Italy are net receivers of spillover and those of US and UK are net transmitters of spillovers before and during COVID-19. Conversely, the REIT of Canada and Germany (France) switches from net receivers (contributors) of spillovers before the pandemic to net contributors (receivers) during the COVID-19. Finally, we show that News Sentiment index, Geopolitical Risk index, Economic Policy Uncertainty index, US Treasury yield, and Stock Volatility index influence the spillover magnitude across quantiles. © 2023 Elsevier Inc.
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We assessed the immunogenicity of ChAdOx1 nCoV-19 vaccination by evaluating the levels of SARS-CoV-2 IgG after vaccination and investigated the effect of diverse factors such as gender, age, and adverse reactions after vaccination. The study included a total of 1028 serum samples from 452 healthcare workers. SARS-CoV-2 IgG levels were assessed using the SARS-CoV-2 IgG II Quant assay. Participants completed a questionnaire regarding the intensity and duration of adverse reactions after vaccination. The seropositive rates after the first and second doses were 95.5% and 100%, respectively. The median antibody levels after the second dose showed a 4.2-fold increase compared with the first. Five months after the second dose, the median antibody levels decreased by 3.5-fold. The antibody levels in men were lower than those in women after the first dose and were higher after the second dose. There was no difference according to age groups after the first dose, but after the second dose, in subjects aged 50 and above, the rise in antibody levels was less than that in other age groups. The antibody levels among participants with moderate or severe symptoms were significantly higher than those among participants with mild symptoms after the first dose. There were no statistically significant differences according to the duration of symptoms. We could assume that different age groups and genders might have different immunogenicity following vaccination. The intensity of adverse symptoms was positively correlated with the antibody levels, implying that higher immunogenicity is related to the intensity of adverse symptoms after vaccination. © 2023 The Scandinavian Foundation for Immunology.
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This study examines the spillovers and connectedness between oil and the African stock markets under bearish, normal, and bullish market conditions. Using the quantile connectedness method, we find higher spillovers under bearish market conditions than in both tranquil and bullish market conditions. Oil is a net transmitter of spillovers in the African markets. Furthermore, Ghana, Kenya, Nigeria, and South Africa are net receivers of spillovers, and Tunisia, Egypt, Morocco, and Mauritius are net transmitters of spillovers in the lower quantile. In the median quantile, Ghana shifts to being a net transmitter of spillovers, whereas Egypt becomes a net receiver of spillovers. In the upper quantiles, all markets are net transmitters of spillovers, except for Mauritius and Egypt. We find a strong connectedness between oil and the Nigerian market during bearish and tranquil market conditions which alleviates the bullish market scenario. Moreover, spillovers reached the maximum level in early 2020, corresponding to the first wave of the COVID-19 pandemic. The portfolio analysis shows that an optimally weighted portfolio offers the best downside risk for all markets. The hedged portfolio offers the best risk reduction for all economies. © 2023 Economic Society of Australia, Queensland
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This paper examines the quantile dependence, connectedness, and return spillovers between gold and the price returns of leading cryptocurrencies, using quantile cross-spectral, the return spillovers based the quantile VAR, and quantile connectedness approaches. The results show that the dependencies within cryptocurrencies are highly symmetric and sensitive to different quantile arrangements. Under normal market conditions, we find a high positive dependence within cryptocurrencies and a low positive dependence between cryptocurrencies and gold. The dependence is higher at long term than intermediate- and short- terms before the pandemic during bearish market conditions. In contrast, the degree of dependence decreases at the intermediate- and long-terms during COVID-19 period than before. Moreover, the magnitude of return spillovers is higher at lower quantile (bearish market) than upper quantile (bullish market). Gold serves as a safe haven and diversifier asset for cryptocurrencies during COVID-19 outbreak at both intermediate and long terms. © 2023 Elsevier B.V.
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Microfluidic biosensors integrating fluid control, target recognition, as well as signal transduction and output, have been widely used in the field of disease diagnosis, drug screening, food safety and environmental monitoring in the past two decades. As the central part and technical characteristics of microfluidic biosensors, the fluid control is not only associated with accuracy and convenience of the sensors, but also affects the material selection and working mode of the sensors. This review summarizes the fluid driving forces for microfluidic biosensors, including gravity, capillary force, centrifugal force, pressure, light, sound, electrical, and magnetic forces. Then, the recent advances in microfluidic biosensors for the detection of viruses, cells, nucleic acids, proteins and small molecules are discussed. Finally, we propose the current challenges and future perspectives of microfluidic biosensors. We hope this review can provide readers with a new perspective to understand the technical characteristics and application potential of microfluidic biosensors.Copyright © 2022 Elsevier B.V.
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Purpose: To explore the evaluation between tourists' and residents' satisfaction with the tool of Importance-Satisfaction Analysis originally introduced by Importance-Performance Analysis. Design/methodology/approach: A survey was conducted at Anseong Matchum Land, the venue of the festival, and respondents were selected by the convenience sampling method. Also, rest areas at the festival site were used for data collection and 309 out of 400 were judged to be valid. Included in the questionnaires was a series of Likert-type questions about the respondent's satisfaction with 18 attributes of the festival and the importance of these attributes to overall satisfaction with the festival. Findings: The results of this research show that the average degree of importance for the 18 attributes is 3.89, and the degree of satisfaction is 3.02. The result identified that parking lot, rest area, and washroom were found included in "Concentrate Here" quadrant of the ISA matrix as needed to prior management in this festival. Research limitations/implications: This study tried to look into local heritage festival regarding comparative per-ception between festival goers and local residents with ISA to provide that actual problems and potential solutions to the decision-makers of the city to make a sustainable festival. However, it is difficult to extend the results of this festival to other festivals and further research is needed in the future. Originality/value: This research tried to find out the gap between perceived Importance and Satisfaction and to identify actual management problems regarding facilities and services of the festival by ISA analysis originally introduced by Importance-Performance Analysis. This study suggested what festival organizers should prepare for the festival that will be activated after the Covid 19 pandemic. © 2023 People and Global Business Association.
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Purpose: This study aims to examine the tail connectedness between the Chinese and Association of Southeast Asian Nations (ASEAN) stock markets. More specifically, the authors measure the return spillovers at three quantile levels: median (t = 0.5), lower extreme (t = 0.05) and upper extreme (t = 0.95). The connectedness at extreme upper and lower quantiles provides insightful information to investors regarding tail risk propagation, which ultimately suggests that investors adjust their portfolios according to the extreme bullish and bearish market conditions. Design/methodology/approach: The authors employ the quantile connectedness approach of Ando et al. (2022) to examine the quantile transmission mechanism among the ASEAN and Chinese stock markets. Findings: The results show significant evidence of a higher level of connectedness between Chinese and ASEAN stock markets at extreme upper and lower quantiles compared to the median quantiles, which suggests the use of a quantile-based connectedness approach instead of an average-measure-based one. Furthermore, the time-varying connectedness analysis shows that the total spillovers reach the highest peaks during the global financial crisis, the Chinese stock market crash and the COVID-19 pandemic at the upper, lower and median quantiles. Finally, the static and dynamic pairwise spillovers between the Chinese and ASEAN markets vary over quantiles as well. Originality/value: This study is the first attempt to examine quantile vector autoregression (VAR)-based return spillovers between China and ASEAN stock markets during different market statuses. Besides, the COVID-19 has intensified the uncertainty in Asian countries, mainly China and ASEAN economies. © 2023, Emerald Publishing Limited.
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BACKGROUND: Disinfection is one of the most effective ways to block the rapid transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Due to the prolonged coronavirus disease 2019 (COVID-19) pandemic, disinfectants have become crucial to prevent person-to-person transmission and decontaminate hands, clothes, facilities and equipment. However, there is a lack of accurate information on the virucidal activity of commercial disinfectants. AIM: To evaluate the virucidal efficacy of 72 commercially available disinfectants constituting 16 types of ingredients against SARS-CoV-2. METHODS: SARS-CoV-2 was tested with various concentrations of disinfectants at indicated exposure time points as recommended by the manufacturers. The 50% tissue culture infectious dose assay was used to calculate virus titre, and trypan blue staining and CCK-8 were used to assess cell viability after 3-5 days of SARS-CoV-2 infection. FINDINGS: This study found that disinfectants based on 83% ethanol, 60% propanol/ethanol, 0.00108-0.0011% sodium dichloroisocyanurate and 0.497% potassium peroxymonosulfate inactivated SARS-CoV-2 effectively and safely. Although disinfectants based on 0.05-0.4% benzalkonium chloride (BAC), 0.02-0.07% quaternary ammonium compound (QAC; 1:1), 0.4% BAC/didecyldimethylammonium chloride (DDAC), 0.28% benzethonium chloride concentrate/2-propanol, 0.0205-0.14% DDAC/polyhexamethylene biguanide hydrochloride (PHMB) and 0.5% hydrogen peroxide inactivated SARS-CoV-2 effectively, they exhibited cytotoxicity. Conversely, disinfectants based on 0.04-4% QAC (2:3), 0.00625% BAC/DDAC/PHMB, and 0.0205-0.14% and 0.0173% peracetic acid showed approximately 50% virucidal efficacy with no cytotoxicity. Citric acid (0.4%) did not inactivate SARS-CoV-2. CONCLUSION: These results indicate that most commercially available disinfectants exert a disinfectant effect against SARS-CoV-2. However, re-evaluation of the effective concentration and exposure time of certain disinfectants is needed, especially citric acid and peracetic acid.
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Credit card usage has risen dramatically as a result of rapid advancements in electronic commerce and the unexpected circumstance of COVID. With credit cards becoming the most popular payment method for both offline and online transactions, the number of cases of fraud associated with them is rapidly increasing. In case of online fraud, it is not necessary for the perpetrators to be present at the scene of crime. The fraudulent activities can be accomplished by them in the seclusion of their homes through a multitude of methods for disguising their identities. VPNs are one way to obscure one's identity, as is routing communication through any Tor network for the victim, making it difficult to track back the culprit. © 2022 IEEE.
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Background. Centers for Disease Control and Prevention (CDC) recommends 5 to 20 days of isolation for COVID-19 patients depending on symptom duration and severity regardless of genomic PCR results or vaccination history. However, in real clinical practice, more individualized approach is required. We thus developed clinical scoring system to predict viable viral shedding in a given patient by using various factors affecting viable viral shedding. Methods. We prospectively enrolled adult patients with SARS-CoV-2 infection admitted to tertiary hospital and day care center between February 2020 and January 2022. The daily dense respiratory sampling (i.e. saliva, sputum, or nasopharyngeal swabs) during the hospital and day care center stay were obtained. Genomic RNA viral load and viral culture were performed for these samples. Clinical predictors of negative viral culture results were identified using survival analysis and multivariable analysis. Results. A total of 612 samples from 121 patients of varying degrees of severity were obtained. Of these, 494 (81%) samples were saliva, 63 (10%) were nasopharyngeal swab, and the remaining 55 (9%) were sputum. Of these 612 specimens, 154 (25%) samples revealed positive viral culture results. Univariate and multivariable Cox's time varying proportional hazard model revealed that symptom onset day, viral copy number, disease severity, organ transplant recipient, gender, and vaccination status were independently associated with viral culture results. We thus developed the 5-factor model from -3 to 3 points: viral copy number (-3 to 3 points depending on copy number), disease severity (1 point to moderate to critical diseases), organ transplant recipient (2 points), gender (-1 points to male), and vaccination status (-2 points to fully vaccinated status). The predictive culture-negative rates were calculated through the symptom onset day and the score of the day the sample was collected. Conclusion. Our clinical scoring system can provide objective probability of negative culture results in a given COVID-19 patient with genomic viral load, and appears to be useful to decide de-isolation policy depending on individualized factors associated with viable viral shedding beyond simple symptom-based isolation strategy by CDC.
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Background. Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) variant strain B.1.1.529 (omicron) has been less virulent than SARS-CoV-2 B.1.617.2 variant (delta), but there are limited data on the comparison of the cause of death between delta variant and omicron variant infections. We thus compared the causes of death in COVID-19 patients with the delta variant and omicron variant. Methods. We retrospectively reviewed the medical records of adult patients with COVID-19 who were admitted at Asan Medical Center, Seoul, South Korea, between July 2021 and March 2022. We divided into delta-variant dominant period (from July 2021 to December 2021) and omicron-dominant period (from February 2022 to March 2022) with the exclusion of January 2022 because this period was overlapping of delta and omicron variant. The causes of death were classified into COVID-19-associated pneumonia, other causes, and indeterminate cause. Results. A total of 654 patients with COVID-19 were admitted and 42 (6.4%) died during the omicron dominant period (between February and March 2022), while a total of 366 patients with COVID-19 were hospitalized and 42 (11.5%) died during the delta dominant period (between July and December 2021). The primary cause of death was COVID-19-associated pneumonia in 64% (27/42) during the omicron era whereas that was COVID-19-associated pneumonia in 88% (37/42) during the delta era (p value=0.01) (Table 1). Conclusion. We found that about two thirds of patients with omicron variant infection died due to COVID-19, while the majority of patients with delta variant infection died due to COVID-19.
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With the rapid development and spread of non-face-to-face digital technologies and services due to the spread of COVID-19, real-time non-face-to-face online meetings, education, telemedicine, online collaboration, telecommuting, various non-face-to-face tasks in the financial sector, and the sharing economy are frequent. As a result, network traffic increases and the demand for real-time security of multimedia is increasing. Security of information, including image content, is an essential part of today's communication technology and is very important for safe transmission. In this paper, we design a 5-neighbor programmable cellular automata (FNPCA) based ROI (region of interest) image encryption system that can effectively reduce computational cost and maintain an appropriate level of security. © 2022 IEEE.