Spatialtemporal evolution characteristics of ozone in China and its response to urbanization.

Based on the background of urbanization in China, we used the dynamic spatial panel Durbin model to study the driving mechanism of ozone pollution empirically. We also analyzed the spatial distribution of ozone driving factors using the GTWR. The results show that: i) The average annual increase of ozone concentration in ambient air in China from 2015 to 2019 was 1.68µg/m3, and 8.39µg/m3 elevated the year 2019 compared with 2015. ii) The Moran's I value of ozone in ambient air was 0.027 in 2015 and 0.209 in 2019, showing the spatial distribution characteristics of "east heavy and west light" and "south low and north high". iii) Per capita GDP industrial structure, population density, land expansion, and urbanization rate have significant spillover effects on ozone concentration, and the regional spillover effect is greater than the local effect. R&D intensity and education level have a significant negative impact on ozone concentration. iv) There is a decreasing trend in the inhibitory effect of educational attainment and R&D intensity on ozone concentration, and an increasing trend in the promotional effect of population urbanization rate, land expansion, and economic development on ozone concentration. Empirical results suggest a twofold policy meaning: i) to explore the causes behind the distribution of ozone from the new perspective of urbanization, and to further the atmospheric environmental protection system and ii) to eliminate the adverse impacts of ozone pollution on nature and harmonious social development.

Characterization of the radical scavenging and antioxidant activities of danshensu and salvianolic acid B.

Danshensu (3-(3,4-dihydroxyphenyl) lactic acid) and salvianolic acid B, two natural phenolic acids of caffeic acid derivatives isolated from Salvia miltiorrhiza root of the most widely used traditional Chinese medicine for the treatment of various cardiovascular diseases, have been reported to have potential protective effects from oxidative injury. To better understand their biological functions, the in vitro radical scavenging and antioxidant activities of danshensu and salvianolic acid B were evaluated along with vitamin C. Both danshensu and salvianolic acid B exhibited higher scavenging activities against free hydroxyl radicals (HO()), superoxide anion radicals (O(2)(-)), 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and 2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals than vitamin C. In contrary, danshensu and salvianolic acid B showed weaker iron chelating and hydrogen peroxide (H(2)O(2)) scavenging activities than vitamin C. As expressed as vitamin C equivalent capacity (VCEAC), the relative VCEAC values (mg/100ml) were in the order of salvianolic acid B (18.59) > danshensu (12.89) > vitamin C (10.00) by ABTS radical assay. The protective efficiencies against hydrogen peroxide induced human vein vascular endothelial cell damage were correlated with their antioxidant activities. Analysis of structure-activity relationship of these two compounds showed that the condensation and conjugation of danshensu and caffeic acid appears important for antioxidant activity. These results indicated that danshensu and salvianolic acid B are efficient radical scavengers and antioxidants, and salvianolic acid B is superior to danshensu. Their radical scavenging and antioxidant properties might have potential applications in food and healthcare industry.

Hepatitis C virus may infect extrahepatic tissues in patients with hepatitis C.

AIM:To explore the status of extrahepatic hepatitis C virus (HCV) infection and replication in hepatitis C patients,and its potential implication in HCV infection and pathogenicity.METHODS:By reverse-transcriptase poly-merase chain reaction (RT-PCR),in situ hybridization (ISH) and immunohis-tochemistry, HCV RNA, HCV replicative intermediate (minus-strand of HCV RNA), and HCV antigens were detected in 38 autopsy extrahepatic tissue specimens (including 9 kidneys, 9 hearts, 9 pancreas, 5 intestines, 2 adrenal glands, 2 spleens, 1 lymph node, and 1 gallbladder) from 9 hepatitis C patients, respectively; and the status of HCV replication in extrahepatic tissues was studied.RESULTS:By RT-PCR, all 9 patients were positive for HCV RNA in kidney, heart, pancreas, and intestine, but only 6(66.7%) patients were positive for HCV replicative intermediate. HCV RNA and HCV antigens were detected in kidney, heart, pancreas, intestine, adrenal gland, lymph node, and gallbladder in 5(55.6%) and 6(66.7%) patients by ISH and immuno-histochemistry, respectively. HCV RNA and HCV antigens were not detected in these extrahepatic organs in 3(33.3%) patients, although their livers were positive for HCV.HCV replicative intermediate detected by RT-PCR was consistent with HCV RNA and HCV antigens detected by ISH and immunohistochemistry (Kappa =0.42-0.75). HCV RNA and HCV antigens were detected in myocardial cells, epithelial cells of intestinal gladular, interstitial cells of kidney, epithelial cells of tubules and glomerulus, pancreas acinar cells and epithelial cells of pancreatic duct, epithelial cells of mucous membrane sinus of gallbladder, cortex and medulla cells in adrenal gland,and mononuclear cells in lymph node. HCV RNA was also detected in bile duct epithelial cells, sinusoidal cells, and mononuclear cells in liver tissues by ISH.CONCLUSION:HCV can infect extrahepatic tissues, and many various tissue cells may support HCV replication; extrahepatic HCV infection and replication may be of concomitant state in most of patients with hepatitis C. The infected extrahepatic tissues might act as a reservoir for HCV, and play a role in both HCV persistence and reactivation of infection. HCV as an etiologic agent replicating and expressing viral proteins in extrahepatic tissues itself contributes to extrahepatic syndrome associated-HCV infection in a few patients with chronic HCV infection.