Tropical cyclones（TCs） constitute one of the major atmospheric activities affecting the air quality of the Pearl River Delta region. In this study, the impact of TCs on air quality in Hong Kong during the TC active ...Tropical cyclones（TCs） constitute one of the major atmospheric activities affecting the air quality of the Pearl River Delta region. In this study, the impact of TCs on air quality in Hong Kong during the TC active season（July–October） from 2000 to 2015 is investigated. It is found that 57.5% of days with concentration of particulate matter with an aerodynamic diameter 10 μm（PM（10）） above the 90th percentile are related to TC activity. TCs in three regions, located to the east, southeast, and southwest of Hong Kong, have obvious impacts on pollutant concentration. When TCs are located east of Hong Kong near Taiwan, 65.5%/38.7% of the days have high or extremely high PM（10）/ozone（O3） levels, which are associated with northerly wind, sinking motion, and relatively low precipitation. When TCs are located southeast of Hong Kong, 48.1%/58.2% of the days have high pollution levels, associated mainly with continental air mass transport. When TCs are south or west of Hong Kong, only 20.8%/16.9% of the days have high PM（10）/O3 levels, and the air quality in Hong Kong is generally good or normal due to TC-associated precipitation, oceanic air mass transport, and an enhanced rising motion. The higher chance of high O3 days when TCs are present between Hong Kong and Taiwan, possibly due to lower-than-normal precipitation along the east coast of China under TC circulation. The results in this study highlight the important influence of TC position and associated atmospheric circulations on the air quality in Hong Kong.展开更多
目的探究肝细胞癌中分泌性富含半胱氨酸的酸性蛋白(secreted protien acidic and rich in cysteine,SPARC)表达及其与糖酵解作用的相关调节机制。方法选取肝癌细胞HepG2、Hep3B、Huh7,分别稳定转染SPARC质粒和SPARC siRNA,应用比色法检...目的探究肝细胞癌中分泌性富含半胱氨酸的酸性蛋白(secreted protien acidic and rich in cysteine,SPARC)表达及其与糖酵解作用的相关调节机制。方法选取肝癌细胞HepG2、Hep3B、Huh7,分别稳定转染SPARC质粒和SPARC siRNA,应用比色法检测2种转染的细胞中糖酵解关键酶己糖激酶(HK)和乳酸脱氢酶-A(LDHA)的活性变化。结果转染SPARC质粒的3种肝癌细胞中HK-Ⅱ、LDHA的活性较对照组明显下降,3种细胞中HK-Ⅱ相对吸光度分别降低至(57.45±5.05)%,(56.1±5.70)%,(49.73±7.06)%;LDHA相对吸光度分别降低至(50.53±8.07)%,(54.38±2.08)%,(42.34±3.44)%;差异均有统计学意义(P<0.05);反之,siRNA抑制SPARC表达的肝癌细胞中,HK-Ⅱ、LDHA活性较对照组明显上调,3种细胞中HK-Ⅱ相对吸光度分别上调至(174.20±8.41)%,(166.69±9.71)%,(152.84±3.39)%;LDHA的相对吸光度分别上调至(176.65±6.85)%;(163.24±6.44)%;(151.25±6.75)%,差异具有统计学意义(P<0.05)。结论肝细胞癌中,SPARC通过负性调控糖酵解作用的关键酶抑制糖酵解。展开更多
In this note,we generalize an extension theorem in [Le-Sesum] and [Xu-Ye-Zhao] of the mean curvature flow to the Hk mean curvature flow under some extra conditions.The main difficulty in proving the extension theorem ...In this note,we generalize an extension theorem in [Le-Sesum] and [Xu-Ye-Zhao] of the mean curvature flow to the Hk mean curvature flow under some extra conditions.The main difficulty in proving the extension theorem is to find a suitable version of Michael-Simon inequality for the Hk mean curvature flow,and to do a suitable Moser iteration process.These two problems are overcome by imposing some extra conditions which may be weakened or removed in our forthcoming paper.On the other hand,we derive some estimates for the generalized mean curvature flow,which have their own interesting.展开更多
基金financially supported by the City University of Hong Kong(Shenzhen)Research Institute Postdoc Fellowshipthe National Natural Science Foundation of China(Project No.41675062)the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.City U 11306417)
文摘Tropical cyclones（TCs） constitute one of the major atmospheric activities affecting the air quality of the Pearl River Delta region. In this study, the impact of TCs on air quality in Hong Kong during the TC active season（July–October） from 2000 to 2015 is investigated. It is found that 57.5% of days with concentration of particulate matter with an aerodynamic diameter 10 μm（PM（10）） above the 90th percentile are related to TC activity. TCs in three regions, located to the east, southeast, and southwest of Hong Kong, have obvious impacts on pollutant concentration. When TCs are located east of Hong Kong near Taiwan, 65.5%/38.7% of the days have high or extremely high PM（10）/ozone（O3） levels, which are associated with northerly wind, sinking motion, and relatively low precipitation. When TCs are located southeast of Hong Kong, 48.1%/58.2% of the days have high pollution levels, associated mainly with continental air mass transport. When TCs are south or west of Hong Kong, only 20.8%/16.9% of the days have high PM（10）/O3 levels, and the air quality in Hong Kong is generally good or normal due to TC-associated precipitation, oceanic air mass transport, and an enhanced rising motion. The higher chance of high O3 days when TCs are present between Hong Kong and Taiwan, possibly due to lower-than-normal precipitation along the east coast of China under TC circulation. The results in this study highlight the important influence of TC position and associated atmospheric circulations on the air quality in Hong Kong.
文摘目的探究肝细胞癌中分泌性富含半胱氨酸的酸性蛋白(secreted protien acidic and rich in cysteine,SPARC)表达及其与糖酵解作用的相关调节机制。方法选取肝癌细胞HepG2、Hep3B、Huh7,分别稳定转染SPARC质粒和SPARC siRNA,应用比色法检测2种转染的细胞中糖酵解关键酶己糖激酶(HK)和乳酸脱氢酶-A(LDHA)的活性变化。结果转染SPARC质粒的3种肝癌细胞中HK-Ⅱ、LDHA的活性较对照组明显下降,3种细胞中HK-Ⅱ相对吸光度分别降低至(57.45±5.05)%,(56.1±5.70)%,(49.73±7.06)%;LDHA相对吸光度分别降低至(50.53±8.07)%,(54.38±2.08)%,(42.34±3.44)%;差异均有统计学意义(P<0.05);反之,siRNA抑制SPARC表达的肝癌细胞中,HK-Ⅱ、LDHA活性较对照组明显上调,3种细胞中HK-Ⅱ相对吸光度分别上调至(174.20±8.41)%,(166.69±9.71)%,(152.84±3.39)%;LDHA的相对吸光度分别上调至(176.65±6.85)%;(163.24±6.44)%;(151.25±6.75)%,差异具有统计学意义(P<0.05)。结论肝细胞癌中,SPARC通过负性调控糖酵解作用的关键酶抑制糖酵解。
文摘In this note,we generalize an extension theorem in [Le-Sesum] and [Xu-Ye-Zhao] of the mean curvature flow to the Hk mean curvature flow under some extra conditions.The main difficulty in proving the extension theorem is to find a suitable version of Michael-Simon inequality for the Hk mean curvature flow,and to do a suitable Moser iteration process.These two problems are overcome by imposing some extra conditions which may be weakened or removed in our forthcoming paper.On the other hand,we derive some estimates for the generalized mean curvature flow,which have their own interesting.
