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1.
Sociol Forum (Randolph N J) ; 2022 Jun 09.
Article in English | MEDLINE | ID: covidwho-1883232

ABSTRACT

We trace the crafting of expert narratives during the initial months of the COVID-19 pandemic in Mainland China, Hong Kong, and the United States. By expert narratives, we refer to how experts drew different lessons from past disease experiences to guide policymakers and the public amidst uncertainty. These expert narratives were mobilized in different sociopolitical contexts, resulting in varying configurations of expertise networks and allies that helped contain and mitigate COVID-19. In Mainland China, experts carefully advanced a managed narrative, emphasizing the new pandemic akin to the 2003 SARS outbreak can be managed while destressing the similar mistakes the government made during the two crises. In Hong Kong, experts invoked a distrust narrative, pointing to a potential coverup of COVID-19 similar to SARS, activating allies in civil society to pressure policymakers to act. In the United States, experts were mired in a contested narrative and COVID-19 was compared to different diseases; varying interpretations of COVID-19's consequences was exacerbated by political polarization. In expert narratives, the resonance of the past is emergent: the past becomes a site of struggle and a cultural object that is presented as potentially useful in solving problems of the present.

2.
Trends Parasitol ; 38(4): 269-271, 2022 04.
Article in English | MEDLINE | ID: covidwho-1757761

ABSTRACT

Mitochondria regulate energy production, cell cycle, and immune signaling. Li et al. recently reported that Toxoplasma gondii induces the shedding of mitochondrial outer membrane to promote its growth. Intriguingly, the hijacking of host mitochondria has been shown to play an essential role in the pathogenesis of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).


Subject(s)
COVID-19 , Toxoplasma , Humans , Mitochondria/metabolism , SARS-CoV-2 , Toxoplasma/physiology
3.
Build Environ ; 212: 108831, 2022 Mar 15.
Article in English | MEDLINE | ID: covidwho-1654126

ABSTRACT

In the era of Corona Virus Disease 2019 (COVID-19), inappropriate indoor ventilation may turn out to be the culprit of microbial contamination in enclosed spaces and deteriorate the environment. To collaboratively improve the thermal comfort, air quality and virus spread control effect, it was essential to have an overall understanding of different ventilation modes. Hence, this study reviewed the latest scientific literature on indoor ventilation modes and manuals of various countries, identified characteristics of different ventilation modes and evaluated effects in different application occasions, wherefore to further propose their main limitations and solutions in the epidemic era. For thermal comfort, various non-uniform ventilation modes could decrease the floor-to-ceiling temperature difference, draft rate or PPD by 60%, 80% or 33% respectively, or increase the PMV by 45%. Unsteady ventilation modes (including intermittent ventilation and pulsating ventilation) could lower PPD values by 12%-37.8%. While for air quality and virus spread control, non-uniform ventilation modes could lower the mean age of air or contaminants concentration by 28.3%-47% or 15%-47% respectively, increase the air change efficiency, contaminant removal effectiveness or protection efficiency by 6.6%-10.4%, 22.6% or 14%-50% respectively. Unsteady ventilation mode (pulsating ventilation) could reduce the peak pollutant concentration and exposure time to undesirable concentrations by 31% and 48% respectively. Non-uniform modes and unsteady modes presented better performance in thermal comfort, air quality and virus spread control, whereas relevant performance evaluation indexes were still imperfect and the application scenarios were also limited.

4.
Appl Energy ; 306: 118135, 2022 Jan 15.
Article in English | MEDLINE | ID: covidwho-1509566

ABSTRACT

With the wide spread of novel coronavirus SARS-CoV-2 pandemic around the word, high quality indoor environment and more efficient mechanical ventilation become the new focus of scholars' attention. Stratum ventilation refers to the ventilation mode that the air supply port on the side wall slightly higher than the height of the working area directly sends fresh air into the working breathing area. As an efficient mechanical ventilation mode, it can create a more healthy and comfortable indoor environment. However, the impact caused by airflow characteristic under stratum ventilation on the thermal performance and indoor comfort is noteworthy due to its supply air outlets are close to the occupied zone. It is widely known that parallel turbulent jets are important for the flow structure and air distribution. Hence, an optimum parallel jet spacing (PJS) between two jet centerlines can obviously enhance the fluid interaction and indoor thermal comfort with low energy consumption. Therefore, this study aims to investigate the impact of the PJS on the performance of multi-jet stratum ventilation. A validated Computational Fluid Dynamics (CFD) model was used to conduct the year-round multivariate analysis. A total of eight PJSs, four inlet locations and five climate zones were discussed synthetically. Air distribution performance index (ADPI), ventilation effectiveness (Et ) and economic comfort coefficient were employed as the evaluation indicators to assess the thermal comfort and energy efficiency in various scenarios. Research results indicated that the PJS showed different influences on the indoor thermal comfort and energy utilization efficiency as a result of cooperative effect including energy dissipation, air short-circuit probability, air distribution uniformity and airflow path. Combining with building energy simulation method, the optimum PJSs of stratum ventilation with different air inlet positions in five climate zones were obtained, which can help provide a comfortable indoor thermal environment and improve energy efficiency in a low-cost way. The data and conclusions presented in this study can supplement the theoretical basis for the actual applications of multiple-jet stratum ventilation used in an office.

5.
Signal Transduct Target Ther ; 6(1): 300, 2021 08 11.
Article in English | MEDLINE | ID: covidwho-1351933

ABSTRACT

Elderly people and patients with comorbidities are at higher risk of COVID-19 infection, resulting in severe complications and high mortality. However, the underlying mechanisms are unclear. In this study, we investigate whether miRNAs in serum exosomes can exert antiviral functions and affect the response to COVID-19 in the elderly and people with diabetes. First, we identified four miRNAs (miR-7-5p, miR-24-3p, miR-145-5p and miR-223-3p) through high-throughput sequencing and quantitative real-time PCR analysis, that are remarkably decreased in the elderly and diabetic groups. We further demonstrated that these miRNAs, either in the exosome or in the free form, can directly inhibit S protein expression and SARS-CoV-2 replication. Serum exosomes from young people can inhibit SARS-CoV-2 replication and S protein expression, while the inhibitory effect is markedly decreased in the elderly and diabetic patients. Moreover, three out of the four circulating miRNAs are significantly increased in the serum of healthy volunteers after 8-weeks' continuous physical exercise. Serum exosomes isolated from these volunteers also showed stronger inhibitory effects on S protein expression and SARS-CoV-2 replication. Our study demonstrates for the first time that circulating exosomal miRNAs can directly inhibit SARS-CoV-2 replication and may provide a possible explanation for the difference in response to COVID-19 between young people and the elderly or people with comorbidities.


Subject(s)
COVID-19/genetics , Diabetes Mellitus/genetics , MicroRNAs/genetics , Spike Glycoprotein, Coronavirus/genetics , Adult , Age Factors , Aged , COVID-19/blood , COVID-19/pathology , COVID-19/virology , China , Circulating MicroRNA/blood , Circulating MicroRNA/genetics , Cohort Studies , Diabetes Mellitus/blood , Diabetes Mellitus/pathology , Diabetes Mellitus/virology , Exercise , Exosomes/genetics , Exosomes/metabolism , Exosomes/virology , Female , Gene Expression Regulation , HEK293 Cells , Host-Pathogen Interactions/genetics , Humans , Male , MicroRNAs/blood , Middle Aged , SARS-CoV-2/genetics , SARS-CoV-2/growth & development , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/blood , Virus Replication
9.
Advances in Applied Energy ; : 100040, 2021.
Article in English | ScienceDirect | ID: covidwho-1252370

ABSTRACT

Heating, ventilation and air-conditioning (HVAC) system is favourable for regulating indoor temperature, relative humidity, airflow pattern and air quality. However, HVAC systems may turn out to be the culprit of microbial contamination in enclosed spaces and deteriorate the environment due to inappropriate design and operation. In the context of COVID-19, significant transformations and new requirements are occurring in HVAC systems. Recently, several updated operational guidelines for HVAC systems have been issued by various institutions to control the airborne transmission and mitigate infection risks in enclosed environments. Challenges and innovations emerge in response to operational variations of HVAC systems. To efficiently prevent the spread of the pandemic and reduce infection risks, it is essential to have an overall understanding of impacts caused by COVID-19 on HVAC systems. Therefore, the objectives of this article are to: (a) provide a comprehensive review of the airborne transmission characteristics of SARS-CoV-2 in enclosed spaces and a theoretical basis for HVAC operation guideline revision;(b) investigate HVAC-related guidelines to clarify the operational variations of HVAC systems during the pandemic;(c) analyse how operational variations of HVAC systems affect energy consumption;and (d) identify the innovations and research trends concerning future HVAC systems. Furthermore, this paper compares the energy consumption of HVAC system operation during the normal times versus pandemic period, based on a case study in China, providing a reference for other countries around the world. Results of this paper offer comprehensive insights into how to keep indoor environments safe while maintaining energy-efficient operation of HVAC systems.

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