The climatic and environmental effects of atmospheric aerosols are a hot topic in global science community, and radiative properties of the aerosols are one of the important parameters in assessing climatic change. He...The climatic and environmental effects of atmospheric aerosols are a hot topic in global science community, and radiative properties of the aerosols are one of the important parameters in assessing climatic change. Here we studied the black carbon concentration and absorption coefficient measured with aethalometers, scattering coefficient measured with nephelometers, and single scattering albedo derived at an atmospheric composition watch station in Guangzhou from 2004 to 2007. Our main results are as follows. The data of black carbon concentration and absorption coefficients measured with instruments cannot be directly used until they are measured in parallel with internationally accepted instruments for comparison, calibration, and reduction. After evaluation of the data, the result shows that the monthly mean of BC concentration varies 3.1―14.8 μg·m-3 and the concentration decreases by about 1 μg·m-3 in average over the four years; It is higher in the dry season with a multi-year mean of 8.9 μg/m3 and lower in the rainy season with a multi-year mean of 8.0 μg·m-3; The extreme maximum of monthly mean concentration occurred in December 2004 and extreme minimum in July 2007, and a 4-year mean is 8.4 μg·m-3. It is also shown that monthly mean scattering coefficient derived varies 129 -565 Mm-1, monthly mean absorption coefficient 32-139 Mm-1, and monthly mean single scattering albedo 0.71-0.91, with annual mean values of 0.80, 0.82, 0.79 and 0.84 for 2004, 2005, 2006 and 2007, respectively. Three instruments were used to take simultaneous measurements of BC in PM10, PM2.5, and PM1 and the results showed that PM2.5 took up about 90% of PM10 and PM1 accounted for about 68% of PM2.5, and BC aerosols are mainly present in fine particulates. The variability of BC concentrations is quite consistent between the Nancun station (141 m above sea level) and the Panyu station (13 m above sea level), which are 8 km apart from each other. The concentration in higher altitude station (Panyu) is consistently lower than展开更多
Objective： MicroRNA-21 （miR-21） has been shown to be a key regulator of carcinogenesis. There were few reports about the comparison of serum miR-21 with conventional tumor markers. This study aimed to explore the d...Objective： MicroRNA-21 （miR-21） has been shown to be a key regulator of carcinogenesis. There were few reports about the comparison of serum miR-21 with conventional tumor markers. This study aimed to explore the diagnostic value of circulating miR-21 as a tumor marker in breast cancer （BC） and compare it with CA15 3 and carcinoembryonic antigen （CEA）. Methods： Circulating miR-16 and miR-21 were amplified and quantitatively detected by real-time PCR in 89 BC patients and 55 healthy controls. The levels of CA153 and CEA were measured through assays. Then the sensitivity in diagnosis of BC was compared among miR-21, CA153 and CEA. Results： The level of serum miR-21 was significantly higher in BC patients than controls （P〈0.001）. The sensitivity and specificity of miR-21 were 87.6% and 87.3%, respectively, whereas the sensitivities of CEA and CA153 were only 22.47% and 15.73%. Con^lusions： Compared with CEA and CA153, serum miR-21 has a higher sensitivity in diagnosis of BC. Although not correlated with the status of ER, PR and clinical stages, serum miR-21 may be a potential diagnostic indicator for BC, especially for the early stage.展开更多
目的观察天然药物对牙龈卟啉单胞菌(P orphy rom onas g ing iva lis,P.g ing iva lis)生长的影响,筛选抗菌作用最强的天然药物。方法选用7种天然药物,采用液体稀释法,结合吸光度测定以确定7种天然药物对P.g ing iva lis的最小抑菌浓度(...目的观察天然药物对牙龈卟啉单胞菌(P orphy rom onas g ing iva lis,P.g ing iva lis)生长的影响,筛选抗菌作用最强的天然药物。方法选用7种天然药物,采用液体稀释法,结合吸光度测定以确定7种天然药物对P.g ing iva lis的最小抑菌浓度(M IC)与最小杀菌浓度(M BC)。结果黄芩、三七、白芷、大黄、五倍子、血藤和川芎对P.g ing iva lis的M IC值分别为1、1、0.5、0.0156、1、0.5、0.125 m g/m l;M BC值分别为1、1、0.5、0.0625、1、1、0.25m g/m l。结论7种天然药物对P.g ing iva lis的生长均表现出明显的抑制作用,大黄的抑菌作用最强,川芎其次。展开更多
基金Supported by Natural Science Foundation of China (Grant Nos. U0733004,40375002, 40418008, 40775011)National High Technology R & D Program of China (Grant Nos. 2006AA06A306 and 2006AA06A308)National Basic Research Program of China (Grant No. 2005CB422207)
文摘The climatic and environmental effects of atmospheric aerosols are a hot topic in global science community, and radiative properties of the aerosols are one of the important parameters in assessing climatic change. Here we studied the black carbon concentration and absorption coefficient measured with aethalometers, scattering coefficient measured with nephelometers, and single scattering albedo derived at an atmospheric composition watch station in Guangzhou from 2004 to 2007. Our main results are as follows. The data of black carbon concentration and absorption coefficients measured with instruments cannot be directly used until they are measured in parallel with internationally accepted instruments for comparison, calibration, and reduction. After evaluation of the data, the result shows that the monthly mean of BC concentration varies 3.1―14.8 μg·m-3 and the concentration decreases by about 1 μg·m-3 in average over the four years; It is higher in the dry season with a multi-year mean of 8.9 μg/m3 and lower in the rainy season with a multi-year mean of 8.0 μg·m-3; The extreme maximum of monthly mean concentration occurred in December 2004 and extreme minimum in July 2007, and a 4-year mean is 8.4 μg·m-3. It is also shown that monthly mean scattering coefficient derived varies 129 -565 Mm-1, monthly mean absorption coefficient 32-139 Mm-1, and monthly mean single scattering albedo 0.71-0.91, with annual mean values of 0.80, 0.82, 0.79 and 0.84 for 2004, 2005, 2006 and 2007, respectively. Three instruments were used to take simultaneous measurements of BC in PM10, PM2.5, and PM1 and the results showed that PM2.5 took up about 90% of PM10 and PM1 accounted for about 68% of PM2.5, and BC aerosols are mainly present in fine particulates. The variability of BC concentrations is quite consistent between the Nancun station (141 m above sea level) and the Panyu station (13 m above sea level), which are 8 km apart from each other. The concentration in higher altitude station (Panyu) is consistently lower than
基金supported by National High-Tech Research and Development(863)Program of China(No.2012AA02A504)
文摘Objective： MicroRNA-21 （miR-21） has been shown to be a key regulator of carcinogenesis. There were few reports about the comparison of serum miR-21 with conventional tumor markers. This study aimed to explore the diagnostic value of circulating miR-21 as a tumor marker in breast cancer （BC） and compare it with CA15 3 and carcinoembryonic antigen （CEA）. Methods： Circulating miR-16 and miR-21 were amplified and quantitatively detected by real-time PCR in 89 BC patients and 55 healthy controls. The levels of CA153 and CEA were measured through assays. Then the sensitivity in diagnosis of BC was compared among miR-21, CA153 and CEA. Results： The level of serum miR-21 was significantly higher in BC patients than controls （P〈0.001）. The sensitivity and specificity of miR-21 were 87.6% and 87.3%, respectively, whereas the sensitivities of CEA and CA153 were only 22.47% and 15.73%. Con^lusions： Compared with CEA and CA153, serum miR-21 has a higher sensitivity in diagnosis of BC. Although not correlated with the status of ER, PR and clinical stages, serum miR-21 may be a potential diagnostic indicator for BC, especially for the early stage.
文摘目的观察天然药物对牙龈卟啉单胞菌(P orphy rom onas g ing iva lis,P.g ing iva lis)生长的影响,筛选抗菌作用最强的天然药物。方法选用7种天然药物,采用液体稀释法,结合吸光度测定以确定7种天然药物对P.g ing iva lis的最小抑菌浓度(M IC)与最小杀菌浓度(M BC)。结果黄芩、三七、白芷、大黄、五倍子、血藤和川芎对P.g ing iva lis的M IC值分别为1、1、0.5、0.0156、1、0.5、0.125 m g/m l;M BC值分别为1、1、0.5、0.0625、1、1、0.25m g/m l。结论7种天然药物对P.g ing iva lis的生长均表现出明显的抑制作用,大黄的抑菌作用最强,川芎其次。
