Study on the variation of air pollutant concentration and its formation mechanism during the COVID-19 period in Wuhan.

To prevent the spread of COVID-19 (2019 novel coronavirus), from January 23 to April 8 in 2020, the highest Class 1 Response was ordered in Wuhan, requiring all residents to stay at home unless absolutely necessary. This action was implemented to cut down all unnecessary human activities, including industry, agriculture and transportation. Reducing these activities to a very low level during these hard times meant that some unprecedented naturally occurring measures of controlling emissions were executed. Ironically, however, after these measures were implemented, ozone levels increased by 43.9%. Also worthy of note, PM2.5 decreased 31.7%, which was found by comparing the observation data in Wuhan during the epidemic from 8th Feb. to 8th Apr. in 2020 with the same periods in 2019. Utilizing CMAQ (The Community Multiscale Air Quality modeling system), this article investigated the reason for these phenomena based on four sets of numerical simulations with different schemes of emission reduction. Comparing the four sets of simulations with observation, it was deduced that the emissions should decrease to approximately 20% from the typical industrial output, and 10% from agriculture and transportation sources, attributed to the COVID-19 lockdown in Wuhan. More importantly, through the CMAQ process analysis, this study quantitatively analyzed differences of the physical and chemical processes that were affected by the COVID-19 lockdown. It then examined the differences of the COVID-19 lockdown impact and determined the physical and chemical processes between when the pollution increased and decreased, determining the most affected period of the day. As a result, this paper found that (1) PM2.5 decreased mainly due to the reduction of emission and the contrary contribution of aerosol processes. The North-East wind was also in favor of the decreasing of PM2.5. (2) O3 increased mainly due to the slowing down of chemical consumption processes, which made the concentration change of O3 pollution higher at about 4 p.m.-7 p.m. of the day, while increasing the concentration of O3 at night during the COVID-19 lockdown in Wuhan. The higher O3 concentration in the North-East of the main urban area also contributed to the increasing of O3 with unfavorable wind direction.

Metformin enhances nitric oxide production and diminishes Rho kinase activity in rats with hyperlipidemia.

BACKGROUND: Rho kinase over-activation is associated with nitric oxide (NO) reduction and atherosclerosis. Metformin is favorable for endothelial function improvement and cardiovascular outcomes. Whether cardio-protective effect of metformin is associated with Rho kinase activity is unknown. METHODS: Hyperlipidemia model of rats were established accordingly. Thereafter, medical interventions in terms of atorvastatin, metformin or combined therapy were administered for 4 weeks. Laboratory parameters were compared among each groups at initial, 6 weeks of high-fat and high-cholesterol diet administration, and 4 weeks of medical intervention. Lineal regression analyses were performed. RESULTS: No significant difference of laboratory parameters was observed initially. Six weeks of high-fat and high-cholesterol diet administration, serum levels of cholesterol, C-reactive protein (CRP) level, and Rho kinase activity were significantly increased while NO production was concomitantly reduced in comparison to the sham group. After 4 weeks of medical intervention, CRP level and Rho kinase activity were profoundly diminished while NO production was significantly enhanced in the atorvastatin and metformin groups, and these benefits were further enhanced with combined therapy. Lineal regression analyses showed that Rho kinase activity was negatively correlated with NO production but positively correlated with CRP level. CONCLUSION: In rats with hyperlipidemia, metformin and atorvastatin therapy is favorable for NO production and CRP reduction, which might be associated with Rho kinase activity decrease.

Atorvastatin combined with poly-unsaturated fatty acid confers better improvement of dyslipidemia and endothelium function.

BACKGROUND: Atorvastatin and poly-unsaturated fatty acid (PUFA) are beneficial for lipid-modification, whether atorvastatin plus PUFA could confer better improvement on dyslipidemia and endothelium function is unknown. METHODS: Dyslipidemia model of 40 rabbits were produced with atherogenic diet, and thereafter saline, atorvastatin, PUFA, or atorvastatin plus PUFA were prescribed for 1 week. Ten rabbits given normal diet served as the sham group. Parameters of interest including lipid profiles, endothelium function (nitric oxide, NO) and activation (solution vascular-cellular adhesion molecule, (sVCAM) and intracellular adhesion molecule, (sICAM)), markers of inflammation (C-reactive protein, CRP) and oxidation (malondialdehyde, MDA) were compared among groups. RESULTS: There was no significant difference of parameters among groups at the initial. With 1 week of atherogenic diet administration, serum levels of lipid profiles, sVCAM and sICAM, CRP and MDA were significantly increased, accompanying with profound NO reduction, as compared to the sham group. After 1 week of medical intervention, as compared to the control group (saline administration), dyslipidemia and endothelium function were modestly improved with either atorvastatin or PUFA therapy. Nevertheless, these efficacies were further and significantly enhanced with combined therapy when compared to the control group (p<0.005), suggesting that there was synergistic effects of atorvastatin and PUFA co-therapy in rabbits with dyslipidemia. CONCLUSION: Atorvastatin plus PUFA therapy could immediately contribute to better improvement of lipid-modification and endothelium function in rabbits with dyslipidemia.

Synergistic effects of colchicine combined with atorvastatin in rats with hyperlipidemia.

BACKGROUND: Inflammation and endothelial dysfunction is implicated in the atherosclerosis initiation and progression in the setting of hyperlipidemia. Colchicine is a potent anti-inflammatory agent and whether colchicine combined with atorvastatin has synergistic effects on inflammation amelioration and endothelial function improvement is unknown. METHODS: Hyperlipidemic rat model was produced by high-fat and high-cholesterol diet for 6 weeks. Rats with normal diet were served as shame group. In hyperlipidemic group, normal saline, atorvastatin (10 mg/kg body weight/day), colchicines (0.5 mg/kg body weight/day), or atorvastatin combined with colchicines (same dosages) were prescribed for 2 weeks. Serum levels of lipid profile, C-reactive protein (CRP), liver enzyme, lipoprotein associated phospholipase A2 (Lp-PLA2) and nitric oxide (NO) production were serially assessed. RESULTS: Before the beginning of the study, all laboratory variables were comparable among each group. After 6 weeks of hyperlipidemic model production, serum levels of cholesterols, CRP and Lp-PLA2 were significantly increased when compared to sham group, whereas NO production was reduced. With 2 weeks of colchicine therapy, serum levels of CRP and Lp-PLA2 were decreased and NO production was enhanced in the colchicine group in a lipid-lowering independent manner. Added colchicine into atorvastatin therapy further improved NO production and decreased CRP and Lp-PLA2 levels, indicating a potential synergism of colchicine and atorvastatin. CONCLUSION: Colchicine combined with atorvastatin may have stronger protective effects on improving endothelial function and ameliorating inflammation in rats with hyperlipidemia.

Effects of calcitriol on bone mineral density in patients treated with esomeprazole.

CONTEXT: Proton pump inhibitor (PPI) increases the risk of decrease in bone mineral density (BMD). However, whether calcitrol improves this situation is unknown. OBJECTIVE: The current study investigates the effects of calcitriol on BMD in patients with esomeprazole therapy. MATERIALS AND METHODS: Three hundred and eighty-six participants with gastrointestinal ulcerations were enrolled and randomly assigned into controlled and supplemented groups. Participants in the controlled group were prescribed esomeprazole (20 mg/qd), while the supplemented group was prescribed esomeprazole (20 mg/qd) and calcitriol (2.5 µg/qd). BMD, serum levels of calcium, carboxy-terminal collagen crosslinks (CTX), and alkaline-phosphatase (ALP) were assessed. RESULTS: (1) No significant between-group difference of age, gender, smoking, previous glucocorticoid use and hemoglobin level was found; (2) after 10.6 ± 0.8 d of PPI therapy, BMD T score in the controlled group was slightly increased compared with initial (-1.25 ± 0.08 versus -1.28 ± 0.06, p = 0.084), while there was no change in the supplemented group (-1.25 ± 0.05 versus -1.26 ± 0.03, p = 0.308); (3) during study termination, calcium level in the supplemented group was slightly higher than the controlled group (2.05 ± 0.03 mmol/L versus 2.01 ± 0.05 mmol/L, p = 0.073), while no significant differences of CTX (366.57 ± 43.71 pg/mL versus 373.15 ± 50.23 pg/mL, p = 0.036) and ALP were found among these two groups (50.47 ± 9.32 U/L versus 52.23 ± 10.45 U/L, p = 0.075). CONCLUSION: Patients with gastrointestinal ulcerations with esomeprazole therapy, calcitriol supplement showed no efficacy on BMD changes.

3DVar sectoral emission inversion based on source apportionment and machine learning.

Air quality models are increasingly important in air pollution forecasting and control. Sectoral emissions significantly impact the accuracy of air quality models and source apportionment. This paper studied the 3DVar (three-dimensional variational) emission inversion method, which is based on machine learning, and then expanded it to sectoral emission inversion combined with source apportionment. Two machine learning conversion matrices were established to implement this method: a matrix that converts the total pollutant concentration to sectoral source apportionment results and a matrix that converts the sectoral source apportionment results to corresponding emissions. Combined with the O3 (ozone) concentration contributed by VOCs (volatile organic compounds) and NOx (nitrogen oxides) precursors in source apportionment, the inversion ability for O3-NOx-VOCs nonlinear processes was improved. Taking the BTH (Beijing‒Tianjin-Hebei) region from January 15 to 30, 2019, as an example, the results revealed that the regional errors of PM2.5 and O3 in the inversion experiment were reduced by 47% and 45%, respectively, and the temporal errors were reduced by 44% and 16%, respectively.

Mapping high-resolution energy consumption CO2 emissions in China by integrating nighttime lights and point source locations.

High-resolution CO2 emission inventories are essential to accurately assess spatiotemporal patterns of carbon emissions, analyze factors affecting carbon emissions, and develop sound emission reduction policies. The top-down approach is often used to map CO2 emissions from energy consumption due to its simplicity. However, the spatial proxy variables commonly used in this method, such as nighttime light (NL), land use, and population, are difficult to reflect the spatial distribution of CO2 emissions from large point sources. Therefore, this study uses the active fire product provided by Visible Infrared Imaging Radiometer Suite (VIIRS) sensors on Suomi National Polar-Orbiting Partnership (Suomi-NPP) satellite to extract the location of industrial heat sources in China, and then develops an improved CO2 emission estimation model by integrating industrial heat sources, Global Energy Monitor (GEM) power plant location and nighttime lights. The model is used to map CO2 emissions from energy consumption at a resolution of 1 km*1 km from 2012 to 2019 in China. It is found that the overall accuracy of the model is greatly improved at the provincial level, the R2 value is >0.75, and RMSE is distributed in 40-110 Mt. At the grid level, the improved model allocates more carbon emissions to the grid where the point source is located, which makes the spatial distribution of CO2 emissions more reasonable.

The underlying mechanisms of PM2.5 and O3 synergistic pollution in East China: Photochemical and heterogeneous interactions.

The rapid development of Chinese cities is accompanied by air pollution. Although the implementation of air pollution control strategies in recent years has alleviated PM2.5 pollution, O3 pollution and the synergistic pollution of PM2.5 and O3 have become more serious. To understand the underlying chemical interaction mechanisms between PM2.5 and O3, we applied the modified Weather Research and Forecasting model with Chemistry (WRF-Chem) to study the effects of aerosol-photolysis feedback and heterogeneous reactions on the two pollutants and revealed the contribution of different mechanisms in different seasons and regions in Yangtze River Delta (YRD) in eastern China. We found that, through the aerosol-photolysis feedback, PM2.5 decreased the surface photolysis rates JNO2 and JO1D, resulting in a decrease in O3 concentration in the VOC-sensitive area and a slight increase in the NOx-sensitive area. The heterogeneous reactions reduced O3 concentration in the YRD in spring, autumn and winter by consuming HxOy. While in summer, the heterogeneous absorption of NOx decreased O3 in the NOx-sensitive areas and increased O3 in the VOC-sensitive areas. Heterogeneous reactions also promoted the secondary formation of fine sulfate and nitrate aerosols, especially in winter. Through the combined effect of two chemical processes, PM2.5 can lead to a decrease in O3 concentration of -3.3 ppb (-7.6 %), -2.2 ppb (-4.0 %), -2.9 ppb (-6.3 %), and - 5.9 ppb (-18.7 %), in spring, summer, autumn and winter in YRD. Therefore, if the PM2.5 concentration decreases, the weakening effect of PM2.5 on the ozone concentration will be reduced, resulting in the aggravation of ozone pollution. This study is important for understanding the synergistic pollution mechanism and provides a scientific basis for the coordinated control of urban air pollution.

[Correlation between macrophage chemotaxis and disease severity in patients with knee osteoarthritis].

OBJECTIVE: To investigate the enhancement of macrophage chemotaxis in patients with knee osteoarthritis (KOA) and its correlation with the disease severity. METHODS: Eighty patients with KOA admitted from July 2019 to June 2022 were enrolled as the observation group and divided into 29 cases of moderate group, 30 cases of severe group and 21 cases of extremely severe group. At the same time, 30 healthy subjects were included as the control group. The gene expressions of NF-κB, CXC chemokine receptor 7 (CXCR7) and CXC chemokine ligand 12 (CXCL12) in macrophages of each group were analyzed. Visual analogue scale(VAS) was used to evaluate the degree of joint pain. Joint function was evaluated by knee Joint Society Scoring system(KSS). Finally, data analysis was carried out. RESULTS: The expression levels of NF-κB, CXCR7 and CXCL12 in moderate group, severe group and extreme recombination group were higher than those in control group. The VAS, the expression of NF-κB, CXCR7 and CXCL12 in the severe group and the extreme recombination group were higher than those in the moderate group, whereas KSS was lower than that in the moderate group. The VAS, expression levels of NF-κB, CXCR7 and CXCL12 in the extremely severe group were higher than those in the severe group, and KSS was lower than that in the severe group (all P<0.01). The expression levels of NF-κB, CXCR7 and CXCL12 in macrophages were positively correlated with VAS score, but negatively correlated with KSS(all P<0.01). The expression levels of NF-κB, CXCR7 and CXCL12 in macrophages were positively correlated with the severity of disease. After excluding the influence of traditional factors (gender, age and disease duration), multiple linear regression analysis further showed that the expression levels of NF-κB, CXCR7 and CXCL12 were still positively correlated with the severity of disease(all P<0.01). CONCLUSION: The chemotaxis of macrophages in patients with KOA increased with the aggravation of the disease, and was related to the degree of pain and function impairment.

[Component Characteristics and Source Appointment of Volatile Organic Compounds in Lianyungang City].

Volatile organic compounds (VOCs) are important precursors of ozone and particulate matter; thus, their impacts on air quality are particularly significant. To study the composition characteristics and sources of VOCs in Lianyungang City, four national control sites were selected to conduct VOCs sampling and analysis on typical days in spring, summer, and autumn. Concentrations of VOCs, the effects of different components of VOCs on ozone formation were quantified, and the sources of VOCs were analyzed using the Positive Matrix Factorization model. The VOC concentrations were in the range of 27.46×10-9-40.52×10-9 in spring, 45.79×10-9-53.45×10-9 in summer, and 38.84×10-9-46.66×10-9 in autumn. Concentrations of oxygenated compounds accounted for 41%-48% of all measured VOCs. VOC species with higher concentrations were acetone, acrolein, and propionaldehyde, and the concentration of isoprene was higher in summer. Generally, VOC concentrations were higher at 09:00 than at 13:00 when acrolein, ethylene, and dichloromethane concentrations changed greatly. The ozone formation potential (OFP) of oxygenated compounds was the highest, followed by aromatics and alkenes, and the OFP of alkanes was the smallest. The VOC species with higher OFP were acrolein, propylene, and ethylene. The main sources of VOCs in Lianyungang were industry (49%), solvent usage (23%), transportation (14%), paint usage (10%), and natural sources (4%). The results suggest further investigating the oxygenated compounds with higher concentrations and higher OFP in Lianyungang City, and studying the impacts of industrial sources on VOCs.

[Clinical value of carbohydrate antigen 50 and carbohydrate antigen 242 in the diagnosis of colorectal carcinoma].

OBJECTIVE: Carbohydrate antigen 50 (CA50) and 242 (CA242), recently recognized as serum tumor markers, are studied for their value in the diagnosis of the colorectal carcinoma. METHODS: This study included 48 patients with benign bowel disease and 71 patients with colorectal carcinoma, whose serum CA50 and CA242 levels were measured by immunoradiometric assay. RESULTS: The total positivity of CA50 and CA242 in colorectal carcinoma cases were 69.0% and 73.2% respectively, and were only 6.3% and 8.3% in benign cases. In non-metastatic colorectal carcinoma cases, the positivity rates for CA50 and CA242 were 52.8% and 44.4% respectively, which were 82.8% and 88.6% in cases with metastasis. Marked elevation in CA242 level was noted in the patients with colon carcinoma (77.5%). But at early stage of the malignancy, both tumor markers had low sensitivity. CONCLUSION: CA50 and CA242 are valuable tumor markers in the diagnosis of colorectal carcinoma.

[Iron overload and liver diseases].

The awareness of the harm of deficiency in iron, an essential trace elements for the growth of almost all types of biological cells, has long been established. Iron overload, however, is not equally well documented to be related to certain diseases. In this article the author reviews the association of iron overload with some frequent hepatic diseases.

[Relationship of serum iron and ferritin with the indicators for hepatic fibrosis].

OBJECTIVE: To study the relationship of serum iron and ferritin with the indicators for hepatic fibrosis and hepatic iron overload. METHODS: Liver tissue specimens were obtained from 41 patients with benign (16) or malignant (25) liver diseases by 1 second liver biopsy, and routine microscopic examination was performed after haematoxylin-eosin (HE) and Perl's Prussian staining. Atomic absorption spectrum, radioimmunoassay and enzyme-linked immunosorbent assay were respectively employed to examine the serum levels of iron, ferritin, hyaluronic acid, laminin, human procollagen type , and collagen type . RESULTS: Between patients with benign and malignant liver diseases, significant differences were found in the serum ferritin levels (P < 0.05), but not in serum iron levels (P > 0.05). It was also noted that the levels of the indicators for hepatic fibrosis in patients with benign and early-stage malignant diseases varied significantly from the levels in normal subjects, but these differences were not observed between normal subjects and patients with end-stage hepatic malignancies. Serum iron and ferritin were found to be associated with serum laminin levels (serum iron: r=0.439, P=0.031; serum ferritin: r=0.476, P=0.016), and no iron granules detected in the tissue specimens of hepatocellular carcinoma. CONCLUSIONS: Most of the patients with hepatocellular carcinoma have elevated serum ferritin levels. The serum levels of iron and ferritin are statistically correlated with serum laminin level. Obvious reduction of iron content is typical of hepatic malignant tissues in comparison with the benign tissues, and the reduction in the levels of the indicators for hepatic fibrosis might involve the inhibition of collagen synthesis in the tumor tissues from patients with end-stage hepatocellular carcinoma. Most of the cases of alcoholic fatty liver are complicated by liver iron overload, often marked by serum iron and ferritin levels.