Role of Meteorological Parameters in COVID-19 Pandemic Waves in Delhi, India

In this study, the levels of meteorological parameters like maximum temperature (°F), relative temperature (°F), minimum temperature (°F), humidity (%), dew point (°F), wind speed (mph), rainfall (in), and air pressure (in) were analyzed for all three COVID-19 pandemic waves in the NCT of Delhi, India. After doing statistical analysis, the results showed that only a few parameters, like temperature (maximum, minimum, and relative), dew point, humidity, and air pressure, were linked to the start of COVID-19 pandemic waves, and rainfall had nothing to do with COVID-19 during any of the three waves. So, according to the results of this study, the Indian government should take strict steps to stop the spread of the fourth wave of COVID-19 and any other diseases that can spread in urban areas based on the meteorological conditions.

Effect of restraint stress on depression-like behaviors in rats after transient focal cerebral ischemic injury

BACKGROUND： Restraint stress is a typical psychophysiological stressor. Simulating the early passion and difficulty in walking of patients after attack of stroke meets onset features.OBJECTIVE： To evaluate the effect of restraint stress on depression-like behaviors in rats after transient focal cerebral ischemic injury, and to investigate the feasibility for its being as modeling method of depression model after stroke.DESIGN： A randomized controlled animal experiment.SETTING： Department of Clinical Medicine, Faculty of Aerospace Medicine of the Fourth Military Medical University of Chinese PLA.MATERIALS： Forty-eight male Sprague-Dawley rats, weighing 240 - 270 g, provided by the Experimental Animal Center of the Fourth Military Medical University of Chinese PLA were used in the current study.METHODS： The experiments were carried out in the Faculty of Aerospace Medicine of the Fourth Military Medical University of Chinese PLA between August 2005 and August 2006. ①Experiment intervention： The rats were randomized into middle cerebral artery occlusion-reperfusion （MCAO） ＋stress group, simple MCAO group, sham-operation ＋ stress group and simple sham-operation group, with 12 rats in each group.Rats in the first two groups were developed into cerebral ischemia/reperfusion models by suture-occluded method. Rats in the MCAO＋stress group were modeled and restraint stress scheme was performed. At week 5 after modeling, the rats were placed in self-made restraining tubes, 2 hours/time, once a day, for 2 successive weeks. The common carotid artery, external and internal carotid arteries of rats in the latter two groups were exposed. The stress way of sham-operation＋ stress group was the same as that of MCAO＋ stress group. ②The neurological status grading and motor performance evaluation （screen test, rota-rod test and balance beam test） were conducted in rats with simple sham-operation group and MCAO group before, 1st and 28^th days after modeling. Depression-like behavior test was performed in the rats of each group by sucrose preference test and open field test at the end of the experiment.MAIN OUTCOME MEASURES： Changes of depression-like behaviors of rats in each group.RESULTS： Forty-eight rats were involved in the experiment. Two rats with meningeal irritation sign were excluded from simple MCAO group, and one rat in the MCAO＋stress group died of some unclear causes during the experiments. The other 45 rats entered the stage of finial analysis. ① Depression-like behavior assessment results： The rats in the MCAO＋ stress group had a significantly decreased preference for sucrose solution, crossing and rearing scores, and increased immobility duration after the 14-day restraint stress,compared with those in other three groups （all P〈0.05）. ②The neurological status grading and motor performance evaluation： There were significant differences in the two indexes of rats in the simple MCAO group before, 1^st and 28^th days after modeling （P〈0.01）, while there was no significant difference before and 28^th days after modeling （P〉0.05）. There were no significant changes in sham-operation group at each time point （P〉0.05）.CONCLUSION： After being exerted restraint stress, the rats with transient focal ischemic injury may show obvious depression-like behaviors. Therefore, restraint stress can be used as a novel animal modeling method for further studying biological mechanism in central nervous system of post-stroke depression animals.

A Social Intervention Approach to Rehabilitate the Health Psychology of Leftbehind Children with Psychological Problems in Healthcare Settings

Background:Left-behind children are more inclined to generate psychological problems relative to non-leftbehind children,thus how to rehabilitate their health psychology and promote the psychological health development of this special disadvantaged group in healthcare settings should be paid more attention to.Objective:This paper attempts to present a social intervention approach and explore its impact on the rehabilitation of rural leftbehind children’s psychological problems in healthcare settings.Methods:This study firstly designed a social intervention program based on the health psychology theory and the generation causes of left-behind children’s psychological problems,and then three groups were applied to test the effectiveness of the program with comparison analysis.Results:Compared with the control left-behind children(group 2),the left-behind children in the experimental group 1 had positive changes in learning anxiety,physical symptoms,anxiety about people,loneliness tendency,self-blame tendency,allergy tendency,terror tendency and impulse tendency.And their mental health can be rehabilitated to the level of non-left-behind children in group 3.Conclusion:This study revealed positive effects of specially designed social intervention program on the rehabilitation of left-behind children’s psychological problems in healthcare settings.The results have both theoretical and practical implications.

数字化驱动制造业与服务业融合发展的国内外实践考察

通过不同类型产业之间的资源配置,制造业与服务业融合能实现不同部门和产业之间优势互补。借鉴美国和欧洲数字化助推产业融合的发展实践,发现中国制造业和服务业融合中存在数字化营商环境有待优化、缺乏数字化龙头企业引领、数字化人才短缺、质量机制不健全等短板,提出优化数字化营商环境,促进数字化龙头企业引领、培育数字化人才、社会多元化协同为驱动等实现路径。

Emerging concern on air pollution and health:Trade-off between air pollution exposure and physical activity

Air pollution is a major contributor to the global disease burden,especially affecting respiratory and cardiovascular health.However,physical activity is associated with improved lung function,a slower decline in lung function,and lower mortality.The public is more likely to be exposed to air pollution during outdoor physical activity.However,studies on how long-term and short-term exposure to air pollution interacts with physical activity yield inconsistent results,and the thresholds for air pollution and physical activity remain unclear.Thus,more studies are needed to provide sufficient evidence to guide the public to safely engage in outdoor physical activity when exposed to air pollution.

Collaborative control of fine particles and ozone required in China for health benefit

PM2.5 concentration declined significantly nationwide,while O3 concentration increased in most regions in China in 2013–2020.Recent evidences proved that peak season O3 is related to increased death risk from non-accidental and respiratory diseases.Based on these new evidences,we estimate excess deaths associated with long-term exposure to ambient PM2.5 and O3 in China following the counterfactual analytic framework from Global Burden Disease.Excess deaths from non-accidental diseases associated with long-term exposure to ambient O3 in China reaches to 579(95%confidential interval(CI):93,990)thousand in 2020,which has been significantly underestimated in previous studies.In addition,the increased excess deaths associated with long-term O3 exposure(234(95%CI:177,282)thousand)in 2013–2020 offset three quarters of the avoided excess deaths(302(95%CI:244,366)thousand)mainly due to PM2.5 exposure reduction.In key regions(the North China Plain,the Yangtze River Delta and the Fen-Wei Plain),the former is even larger than the latter,particularly in 2017–2020.Health benefit of PM2.5 concentration reduction offsets the adverse effects of population growth and aging on excess deaths attributed to PM2.5 exposure.Increase of excess deaths associated with O3 exposure is mainly due to the strong increase of O3 concentration,followed by population aging.Considering the faster population aging process in the future,collaborative control,and faster reduction of PM2.5 and O3 are needed to reduce the associated excess deaths.

Health risk assessment of dietary exposure to polycyclic aromatic hydrocarbons in Taiyuan, China

Sixteen polycyclic aromatic hydrocarbons （PAHs） were determined in 24 duplicate-diet samples from people in Taiyuan during summer and winter in 2009. Dietary intake of PAHs for 2862 participants was subsequently estimated by a survey in Taiyuan. Results from these 24 samples were compared with a raw food study in Taiyuan in 2008. Three main sources of dietary PAHs are vegetables, wheat flour and fruits, the sum of which contributes 75.95% of PAHs in dietary food. Compared to the estimated value in raw food, much more B[a]Peq （benzo[a]pyrene equivalents） were detected in food samples collected in the duplicate-diet study in Taiyuan （60.75 ng/day）. The cooking process may introduce more B[a]Peq into food, and the relative contribution of 16 PAHs in the diet would be changed during the cooking procedure.

Effect of temperature on Lu’an bituminous char structure evolution in pyrolysis and combustion

In the process of pyrolysis and combustion of coal particles, coal structure evolution will be affected by the ash behavior, which will further affect the char reactivity, especially in the ash melting temperature zone. Lu’an bituminous char and ash samples were prepared at the N_(2) and air atmospheres respectively across ash melting temperature. A scanning electron microscope (SEM) was used to observe the morphology of char and ash. The specific surface area (SSA) analyzer and thermogravimetric analyzer were respectively adopted to obtain the pore structure characteristics of the coal chars and combustion parameters. Besides, an X-ray diffractometer (XRD) was applied to investigate the graphitization degree of coal chars prepared at different pyrolysis temperatures. The SEM results indicated that the number density and physical dimension of ash spheres exuded from the char particles both gradually increased with the increasing temperature, thus the coalescence of ash spheres could be observed obviously above 1100℃. Some flocculent materials appeared on the surface of the char particles at 1300℃, and it could be speculated that β-Si_(3)N_(4) was generated in the pyrolysis process under N_(2). The SSA of the chars decreased with the increasing pyrolysis temperature. Inside the char particles, the micropore area and its proportion in the SSA also declined as the pyrolysis temperature increased. Furthermore, the constantly increasing pyrolysis temperature also caused the reactivity of char decrease, which is consistent with the results obtained by XRD. The higher combustion temperature resulted in the lower porosity and more fragments of the ash.

Increased urbanization reduced the efectiveness of school closures on seasonal infuenza epidemics in China

Background:School closure is a common mitigation strategy during severe infuenza epidemics and pandemics.However,the efectiveness of this strategy remains controversial.In this study,we aimed to explore the efectiveness of school closure on seasonal infuenza epidemics in provincial-level administrative divisions(PLADs)with varying urbanization rates in China.Methods:This study analyzed infuenza surveillance data between 2010 and 2019 provided by the Chinese National Infuenza Center.Taking into consideration the climate,this study included a region with 3 adjacent PLADs in Northern China and another region with 4 adjacent PLADs in Southern China.The efect of school closure on infuenza transmission was evaluated by the reduction of the efective reproductive number of seasonal infuenza during school winter breaks compared with that before school winter breaks.An age-structured Susceptible-Infected-Recovered-Susceptible(SIRS)model was built to model infuenza transmission in diferent levels of urbanization.Parameters were determined using the surveillance data via robust Bayesian method.Results:Between 2010 and 2019,in the less urbanized provinces:Hebei,Zhejiang,Jiangsu and Anhui,during school winter breaks,the efective reproductive number of seasonal infuenza epidemics reduced 14.6%[95%confdential interval(CI):6.2–22.9%],9.6%(95%CI:2.5–16.6%),7.3%(95%CI:0.1–14.4%)and 8.2%(95%CI:1.1–15.3%)respectively.However,in the highly urbanized cities:Beijing,Tianjin and Shanghai,it reduced only 5.2%(95%CI:-0.7–11.2%),4.1%(95%CI:-0.9–9.1%)and 3.9%(95%CI:-1.6–9.4%)respectively.In China,urbanization is associated with decreased proportion of children and increased social contact.According to the SIRS model,both factors could reduce the impact of school closure on seasonal infuenza epidemics,and the proportion of children in the population is thought to be the dominant infuencing factor.Conclusions:Efectiveness of school closure on the epidemics varies with the age structure in the population and social contact patterns.School closure should be recommended in the low urbanized regions in China in the infuenza seasons.

Several major issues concerning the environmental transmission and risk prevention of SARS-CoV-2

Coronavirus disease 2019(COVID-19) is the most serious infectious disease pandemic in the world in a century, and has had a serious impact on the health, safety, and social and economic development of all mankind. Since the earth entered the“Anthropocene”, human activities have become the most important driving force of the evolution of the earth system. At the same time, the epidemic frequency of major human infectious diseases worldwide has been increasing, with more than 70% of novel diseases having zoonotic origins. The review of several major epidemics in human history shows that there is a common rule, i.e., changes in the natural environment have an important and profound impact on the occurrence and development of epidemics. Therefore, the impact of the natural environment on the current COVID-19 pandemic and its mechanisms have become scientific issues that need to be resolved urgently. From the perspective of the natural environment, this study systematically investigated several major issues concerning the environmental transmission and risk prevention of Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2). From a macroscopic temporal and spatial scale, the research focus on understand the impact of the destruction of the natural environment and global changes on the outbreak of infectious diseases;the threat of zoonotic diseases to human health;the regularity for virus diffusion, migration and mutation in environmental media;the mechanisms of virus transmission from animals and environmental media to humans;and environmental safety, secondary risk prevention and control of major epidemics. Suggestions were made for future key research directions and issues that need attention, with a view to providing a reference for the prevention and control of the global coronavirus disease 2019, and to improving the ability of response to major public health emergencies.