Supply of basic necessities to vulnerable populations during the COVID-19 pandemic: Empirical evidence from Shanghai, China.

Background: In spite of initial widespread skepticism, city lockdown has been proved to be an effective short-term tool in containing and delaying the spread of a viral epidemic. The measures to ensure the supply of the basic necessities adequately and equitably, especially for those vulnerable ones has become a major challenge faced by all countries taking a city lockdown measure during the epidemic. Methods: Data was collected through relevant government documents, work records, policy reports, media reports and the online-work information platform designed by the research group. Based on these references, the study analyzed the mainly technical difficulties and the countermeasures of the supply process, and summarized the key characteristics of basic necessities supply strategy for vulnerable groups in Shanghai. Results: The supply strategy for vulnerable groups in Shanghai covers 16 districts, 232 streets and 6,028 neighborhood communities, which has already been in test running in April in some districts. The practical experience in Shanghai solved three key materials supply problems (lack of purchase channels, insufficient material reserves, insufficient transportation capacity) faced by government during the city lockdown, and showed three essential characteristics (overall coordination, community-centered intervention, technical support). Conclusions: The findings in this study may provide some suggestions to other countries about how to better manage the preparation, dispatch and transportation of basic necessities in shortage for those vulnerable ones during the city lockdown.

Associations Between Total Sleep Duration and Cognitive Function Among Middle-Aged and Older Chinese Adults: Does Midday Napping Have an Effect on It?

AIM: The effect of sleep duration on cognitive function has been reported. However, the studies about the combined effects of total sleep duration and midday napping on cognition in elders were limited and inconclusive. We aimed to investigate the associations between total sleep duration, midday napping and cognitive function among middle-aged and older Chinese adults. METHODS: Based on the 3rd wave of the China Health and Retirement Longitudinal Study (CHARLS) in 2015, a total of 9218 participants aged ≥45 years with completed cognition measurements were included. Cognitive functions were assessed by a combined global cognition score of episodic memory and mental status. Information about sleep-related variables, demographic characteristics, and health status were collected by validated questionnaires. Multivariate linear regression models were performed to evaluate the associations between total sleep duration, midday napping, and cognitive function. Stratified analyses were used to explore the potential effect modifier. RESULTS: Overall, the global cognition score was 10.38 ± 4.30 among the participants (mean age: 61.5 ± 8.7 years). For sleep duration, both short sleep and long sleep duration were significantly associated with the increased risk of cognitive impairment after controlling for demographics and other confounders. Compared with sleeping for 7h per day, the adjusted ß-coefficient and 95% CI of the risk of cognitive impairment was -0.967 (95% CIs: -1.191, -0.742) for ≤5h, -0.257 (-0.498, -0.016) for 6h, -0.424 (-0.650, -0.198) for 8h and -0.664 (-0.876, -0.452) for ≥9h. The combined effect analysis indicated that subjects with extended or without naps had a significantly higher risk of cognitive impairment in the ≤5h sleep time group (ref: 7h) and in extended nappers or without naps group (ref: short nappers). Subjects with extended naps or without naps might increase the risk of cognitive impairment, especially those having ≤5h total sleep time. Stratified analysis showed that participants aged ≥60 years without social activity increased the risk of cognitive decline. CONCLUSION: An inverted U-shaped association was observed between total sleep duration and cognitive function in Chinese elders, especially in those aged ≥60 years or without social activity. Short midday naps could mitigate the deleterious effects of poor sleep quality and shorter sleep duration on cognitive function. The findings could help us identify the vulnerable population and decrease the burden of cognitive impairment.

Self-powered ultraviolet photodetector based on an n-ZnO:Ga microwire/p-Si heterojunction with the performance enhanced by a pyro-phototronic effect.

In the present study, a heterojunction made of an individual ZnO microwire via Ga incorporation (ZnO:Ga MW) with a p-Si substrate was constructed to develop a self-powered ultraviolet photodetector. When operated under an illumination of 370 nm light with a power density of ∼ 0.5 mW/cm2, the device exhibited an excellent responsivity of 0.185 A/W, a large detectivity of 1.75×1012 Jones, and excellent stability and repeatability. The device also exhibited a high on/off photocurrent ratio up to 103, and a short rising and falling time of 499/412 µs. By integrating the pyro-phototronic effect, the maximum responsivity and detectivity increased significantly to 0.25 A/W and 2.30×1012 Jones, respectively. The response/recovery time was drastically reduced to 79/132 µs without an external power source. In addition, the effects of light wavelength, power density, and bias voltage on the photocurrent response mediated by the pyro-phototronic effect were systematically characterized and discussed. Our work not only provides an easy yet efficient procedure for constructing a self-powered ultraviolet photodetector but also broadens the application prospects for developing individual wire optoelectronic devices based on the photovoltaic-pyro-phototronic effect.

Initial Public-Health Emergency Response to SARS and COVID-19 Pandemics in Mainland China: A Retrospective Comparative Study.

BACKGROUND: Severe acute respiratory syndrome (SARS) was reported first in China in 2003. The world is currently coping with coronavirus disease-2019 (COVID-19). We conducted a retrospective study to compare the initial public-health emergency response (PHER) to SARS and COVID-19 in mainland China. METHODS: A qualitative comparative study was conducted to compare the PHER timelines to SARS and COVID-19 by selecting six crucial time points. Besides, we explored the speed of spread, peak time and plateau period of SARS and COVID-19, respectively, by comparing the confirmed cases in the same time interval. RESULTS: The government of the People's Republic of China (PRC) accomplished the entire initial PHER to SARS in 127 days and for COVID-19 in 44 days. The speed of PHER for COVID-19 was 83 days faster. The peak time of SARS arose ~80 days later than that of COVID-19. Though the peak number of confirmed daily cases for COVID-19 was fivefold more than that of SARS, the onset of the stabilization period for COVID-19 was >2 months earlier than that of SARS. CONCLUSION: Overall, the speed of the initial PHER to COVID-19 pandemic was faster than that for SARS. Compared with the speed of hospital reporting and government policymaking, the speed of pathogen identification improved the most. The COVID-19 pandemic curve entered a plateau period earlier than the SARS pandemic curve, which suggests that the pandemic was controlled more effectively because of a timely PHER. The PRC government should emphasize improving the ability of hospitals to restrain infectious diseases by enhancing the direct reporting system and cultivating crisis management to empower relevant individuals to make timely scientific decisions.

Early Surveillance and Public Health Emergency Responses Between Novel Coronavirus Disease 2019 and Avian Influenza in China: A Case-Comparison Study.

Background: Since the novel coronavirus disease (COVID-19) has been a worldwide pandemic, the early surveillance and public health emergency disposal are considered crucial to curb this emerging infectious disease. However, studies of COVID-19 on this topic in China are relatively few. Methods: A case-comparison study was conducted using a set of six key time nodes to form a reference framework for evaluating early surveillance and public health emergency disposal between H7N9 avian influenza (2013) in Shanghai and COVID-19 in Wuhan, China. Findings: A report to the local Center for Disease Control and Prevention, China, for the first hospitalized patient was sent after 6 and 20 days for H7N9 avian influenza and COVID-19, respectively. In contrast, the pathogen was identified faster in the case of COVID-19 than in the case of H7N9 avian influenza (12 vs. 31 days). The government response to COVID-19 was 10 days later than that to avian influenza. The entire process of early surveillance and public health emergency disposal lasted 5 days longer in COVID-19 than in H7N9 avian influenza (46 vs. 41 days). Conclusions: The identification of the unknown pathogen improved in China between the outbreaks of avian influenza and COVID-19. The longer emergency disposal period in the case of COVID-19 could be attributed to the government's slower response to the epidemic. Improving public health emergency management could lessen the adverse social effects of emerging infectious diseases and public health crisis in the future.

Enhanced luminescence/photodetecting bifunctional devices based on ZnO:Ga microwire/p-Si heterojunction by incorporating Ag nanowires.

With the disadvantages of indirect band gap, low carrier mobility, and large lattice mismatch with other semiconductor materials, one of the current challenges in Si-based materials and structures is to prepare low-dimensional high-performance optoelectronic devices. In this work, an individual ZnO microwire via Ga-incorproration (ZnO:Ga MW) was employed to prepare a light-emitting/detecting bifunctional heterojunction structure, combined with p-type Si crystal wafer as a hole transporting layer. In a forward-bias regime, red luminescence peaking at around 680 nm was captured. While, the fabricated heterojunction device also exhibited an obvious photoresponse in the ultraviolet wavelengths. Interestingly, the introduction of Ag nanowires (AgNWs) are utilized to increase light output with amplitude 4 times higher than with that of naked wire-based LEDs. Similarly, the performance parameters of the fabricated n-AgNWs@ZnO:Ga MW/p-Si heterojunction photodetector are significantly enhanced, containing a responsivity of 5.52 A W-1, detectivity of 2.34 × 1012 Jones, external quantum efficiency of 1.9 × 103% illuminated under 370 nm at -1 V. We compare this work with previous reported photodetectors based on various ZnO/Si-based materials and structures, some performance parameters are not superior, but our constructed n-AgNWs@ZnO:Ga MW/p-Si heterojunction photodetector has comparable overall characteristics, and our findings stand out especially for providing an inexpensive and suitable pathway for developing low-cost, miniaturized and integrated ultraviolet photodetectors. The demonstration of AgNWs enhanced low-dimensional light-emitting/detecting bifunctional photodiodes can offer a promising scheme to construct high-performance Si-based optoelectronic devices.

Achieving Universal Wearing of Face Masks During the COVID-19 Pandemic: A Practical Solution from Shanghai, China.

BACKGROUND: Face masks are basic protective equipment for preventing respiratory infectious diseases. The measures to properly dispose of and allocate face masks during the early stage of an epidemic caused by respiratory infectious diseases deserve worldwide attention. METHODS: A qualitative research approach was used to document the practice of a citywide face mask-wearing strategy of the Shanghai Municipal Government (called the "Shanghai solution" in this article). Based on data from government work documents, an online face mask-allocation and sales system was built to offer real-time updates of face-mask appointments and sales information in all designated pharmacies and neighborhood committees in Shanghai. RESULTS: In the Shanghai solution, a total of 24.8 million residents in 6,031 committees were covered, in order to achieve universal wearing of face masks during the COVID-19 crisis. Up to 110 million face masks were dispensed to residents in six rounds of face-mask allocation during February to April. This practical experience in Shanghai solved two key problems (insufficient face-mask capacity, protection of vulnerable population) with the supply of face masks by addressing four essential characteristics: overall coordination, on-demand distribution, efficient distribution, and technical support. CONCLUSION: The practice of the citywide face mask-supply strategy of Shanghai could provide several pointers for management of a shortage of emergency materials, dispatch, and transport to other countries during the pandemic.

Characteristics of and Public Health Emergency Responses to COVID-19 and H1N1 Outbreaks: A Case-Comparison Study.

BACKGROUND: Recently, the novel coronavirus disease (COVID-19) has already spread rapidly as a global pandemic, just like the H1N1 swine influenza in 2009. Evidences have indicated that the efficiency of emergency response was considered crucial to curb the spread of the emerging infectious disease. However, studies of COVID-19 on this topic are relatively few. METHODS: A qualitative comparative study was conducted to compare the timeline of emergency responses to H1N1 (2009) and COVID-19, by using a set of six key time nodes selected from international literature. Besides, we also explored the spread speed and peak time of COVID-19 and H1N1 swine influenza by comparing the confirmed cases in the same time interval. RESULTS: The government's entire emergency responses to the epidemic, H1N1 swine influenza (2009) completed in 28 days, and COVID-19 (2019) completed in 46 days. Emergency responses speed for H1N1 was 18 days faster. As for the epidemic spread speed, the peak time of H1N1 came about 4 weeks later than that of COVID-19, and the H1N1 curve in America was flatter than COVID-19 in China within the first four months after the disease emerged. CONCLUSIONS: The speed of the emergency responses to H1N1 was faster than COVID-19, which might be an important influential factor for slowing down the arrival of the peak time at the beginning of the epidemic. Although COVID-19 in China is coming to an end, the government should improve the public health emergency system, in order to control the spread of the epidemic and lessen the adverse social effects in possible future outbreaks.