AIM:To examine how the introduction of endoscopy to gastric cancer screening affected survival prognosis in a regional population. METHODS: The subjects comprised 4261 residents of Kamigoto,Nagasaki Prefecture,who und...AIM:To examine how the introduction of endoscopy to gastric cancer screening affected survival prognosis in a regional population. METHODS: The subjects comprised 4261 residents of Kamigoto,Nagasaki Prefecture,who underwent gastric X-ray examination for gastric cancer screening from 1991 to 1995,and all 7178 residents who underwent endoscopic examination for the same purpose from 1996 to 2003. The analysis evaluated trends in age-adjusted gastric cancer mortality rates and standard mortality ratios (SMRs) among the Kamigoto residents. RESULTS: According to demographic statistics,the 1995 and 2000 age-adjusted gastric cancer mortality rates in Nagasaki Prefecture (per 100 000 population) were 42.6 and 37.3 for males and 18.6 and 16.0 for females,while the corresponding rates in Kamigoto before and after the introduction of endoscopic screening were respectively 51.9 and 28.0,and 26.6 and 6.9. The data obtained in this study were divided into those for two periods,1990-1996 and 1997-2006,and SMRs were calculated separately for males and females. For the first period,the SMR was 1.04 (95% CI 0.50-1.58) for males and 1.54 (95% CI 0.71-2.38) for females,while for the second period the SMR was 0.71 (95% CI 0.33-1.10) for males and 0.62 (95% CI 0.19-1.05) for females. CONCLUSION: Following the introduction of endoscopic examination,gastric cancer death rates decreased in Kamigoto.展开更多
Measurements were performed in spring 2001 and 2002 to determine the characteristics of soil dust in the Chinese desert region of Dunhuang, one of the ground sites of the Asia-Pacific Regional Aerosol Characterization...Measurements were performed in spring 2001 and 2002 to determine the characteristics of soil dust in the Chinese desert region of Dunhuang, one of the ground sites of the Asia-Pacific Regional Aerosol Characterization Experiment （ACE-Asia）. The mean mass concentrations of total suspended particle matter during the spring of 2001 and 2002 were 317μg m^-3 and 307μg m^-3, respectively. Eleven dust storm events were observed with a mean aerosol concentration of 1095μg m^-3, while the non-dusty days with calm or weak wind speed had a background aerosol loading of 196μg m^-3 on average in the springtime. The main minerals detected in the aerosol samples by X-ray diffraction were illite, kaolinite, chlorite, quartz, feldspar, calcite and dolomite. Gypsum, halite and amphibole were also detected in a few samples. The mineralogical data also show that Asian dust is characterized by a kaolinite to chlorite （K/C） ratio lower than 1 whereas Saharan dust exhibits a K/C ratio larger than 2. Air mass back-trajectory analysis show that three families of pathways are associated with the aerosol particle transport to Dunhuang, but these have similar K/C ratios, which further demonstrates that the mineralogical characteristics of Asian dust are different from African dust.展开更多
Jajarm＇s bauxite deposits are mainly diasporic, and they have a low mass ratio of Al2O3/SiO2. It is necessary to increase the run-of-mine mass ratio before feeding the material to the Bayer process. Chemical analysis...Jajarm＇s bauxite deposits are mainly diasporic, and they have a low mass ratio of Al2O3/SiO2. It is necessary to increase the run-of-mine mass ratio before feeding the material to the Bayer process. Chemical analysis indicated that the low-grade bauxite sample from Jajarm contained 43.9wt% Al2O3 and 13.35wt% SiO2, resulting in a mass ratio of 3.29. According to mineralogical studies, the presence of aluminosilicate minerals such as kaolinite, illite, and quartz was the main reason for the decrease of the mass ratio. Microscopic observations revealed that, with the size reduction from -1000＋710 to -38 μm, the liberation degree of diaspore increased from 10% to 60%, and that of aluminosilicates increased from 20% to 85%. Heavy liquids with the densities of 2.8, 3.0, 3.2, and 3.4 g/cm3 were used to evaluate the heavy media separation in three sizes, i.e., -3350＋710, -710＋212, and -212＋125 μm. Laboratory studies confirm that the density of 3.2 g/cm3 can produce the concentrates （in sunk fractions） with recoveries of 89.09%, 91.24%, and 84.68% with the Al2O3/SiO2 mass ratios of 5.03, 5.16, and 5.15 for the -3350＋710, -710＋212, and -212＋ 125 μ m sizes, respectively.展开更多
文摘AIM:To examine how the introduction of endoscopy to gastric cancer screening affected survival prognosis in a regional population. METHODS: The subjects comprised 4261 residents of Kamigoto,Nagasaki Prefecture,who underwent gastric X-ray examination for gastric cancer screening from 1991 to 1995,and all 7178 residents who underwent endoscopic examination for the same purpose from 1996 to 2003. The analysis evaluated trends in age-adjusted gastric cancer mortality rates and standard mortality ratios (SMRs) among the Kamigoto residents. RESULTS: According to demographic statistics,the 1995 and 2000 age-adjusted gastric cancer mortality rates in Nagasaki Prefecture (per 100 000 population) were 42.6 and 37.3 for males and 18.6 and 16.0 for females,while the corresponding rates in Kamigoto before and after the introduction of endoscopic screening were respectively 51.9 and 28.0,and 26.6 and 6.9. The data obtained in this study were divided into those for two periods,1990-1996 and 1997-2006,and SMRs were calculated separately for males and females. For the first period,the SMR was 1.04 (95% CI 0.50-1.58) for males and 1.54 (95% CI 0.71-2.38) for females,while for the second period the SMR was 0.71 (95% CI 0.33-1.10) for males and 0.62 (95% CI 0.19-1.05) for females. CONCLUSION: Following the introduction of endoscopic examination,gastric cancer death rates decreased in Kamigoto.
基金The authors are very grateful to the anonymous reviewers for their constructive suggestions and comments.This research was supported by the National Natural Science Foundation of China(Grant No.40405023)the Chinese National Key Project of Basic Research(Grant G2004CB720200)+1 种基金the Science Foundation of Xi'an Jiaotong University(Grant No.XJJ2004006)a grant from the State Key Laboratory of Loess and Quaternary Geology(SKLLQG),Chinese Academy of Sciences.
文摘Measurements were performed in spring 2001 and 2002 to determine the characteristics of soil dust in the Chinese desert region of Dunhuang, one of the ground sites of the Asia-Pacific Regional Aerosol Characterization Experiment （ACE-Asia）. The mean mass concentrations of total suspended particle matter during the spring of 2001 and 2002 were 317μg m^-3 and 307μg m^-3, respectively. Eleven dust storm events were observed with a mean aerosol concentration of 1095μg m^-3, while the non-dusty days with calm or weak wind speed had a background aerosol loading of 196μg m^-3 on average in the springtime. The main minerals detected in the aerosol samples by X-ray diffraction were illite, kaolinite, chlorite, quartz, feldspar, calcite and dolomite. Gypsum, halite and amphibole were also detected in a few samples. The mineralogical data also show that Asian dust is characterized by a kaolinite to chlorite （K/C） ratio lower than 1 whereas Saharan dust exhibits a K/C ratio larger than 2. Air mass back-trajectory analysis show that three families of pathways are associated with the aerosol particle transport to Dunhuang, but these have similar K/C ratios, which further demonstrates that the mineralogical characteristics of Asian dust are different from African dust.
文摘Jajarm＇s bauxite deposits are mainly diasporic, and they have a low mass ratio of Al2O3/SiO2. It is necessary to increase the run-of-mine mass ratio before feeding the material to the Bayer process. Chemical analysis indicated that the low-grade bauxite sample from Jajarm contained 43.9wt% Al2O3 and 13.35wt% SiO2, resulting in a mass ratio of 3.29. According to mineralogical studies, the presence of aluminosilicate minerals such as kaolinite, illite, and quartz was the main reason for the decrease of the mass ratio. Microscopic observations revealed that, with the size reduction from -1000＋710 to -38 μm, the liberation degree of diaspore increased from 10% to 60%, and that of aluminosilicates increased from 20% to 85%. Heavy liquids with the densities of 2.8, 3.0, 3.2, and 3.4 g/cm3 were used to evaluate the heavy media separation in three sizes, i.e., -3350＋710, -710＋212, and -212＋125 μm. Laboratory studies confirm that the density of 3.2 g/cm3 can produce the concentrates （in sunk fractions） with recoveries of 89.09%, 91.24%, and 84.68% with the Al2O3/SiO2 mass ratios of 5.03, 5.16, and 5.15 for the -3350＋710, -710＋212, and -212＋ 125 μ m sizes, respectively.
