燃气轮机结构紧凑,单位功率重量轻,运行平稳且安全可靠,可以大型化且热效率较高,广泛运用于海上油田,为海上油田生产提供电能、热能。燃气轮机机组滑油系统是其重要组成部分之一,起着润滑、冷却、承载、防蚀、清洁、缓冲等作用,良好的...燃气轮机结构紧凑,单位功率重量轻,运行平稳且安全可靠,可以大型化且热效率较高,广泛运用于海上油田,为海上油田生产提供电能、热能。燃气轮机机组滑油系统是其重要组成部分之一,起着润滑、冷却、承载、防蚀、清洁、缓冲等作用,良好的润滑油品质是保证燃气轮机良好运行的重要保障,某海上油田燃气轮机滑油换新仅运行1600h后,取样化验发现滑油旋转氧弹值(RPVOT)(监测标准ASTM D2272)下降明显,指标由1300快速降至207,已不能满足滑油使用性能要求,参考Solar《索拉透平发动机所使用的润滑油的规格说明书》规范要求(NO. ES 9-224),需要更换滑油,滑油使用寿命远远低于设计寿命。本文对该故障进行原因分析排查,发现该燃气轮机组1#轴承气封气连接短节断裂,高温气封气泄漏至齿轮箱,导致滑油高温氧化。由于该故障较为隐蔽,且排查处理困难,通过系统分析并提出改进措施。希望为其他油田同类型设备故障处理提供参考。展开更多
AIM: To examine the relationships between γ -glutamyltransferase (GGT), alanine-aminotransferase (ALT),aspartate-aminotransferase (AST) and various metabolic parameters, C-reactive protein (CRP) and an oxidative stre...AIM: To examine the relationships between γ -glutamyltransferase (GGT), alanine-aminotransferase (ALT),aspartate-aminotransferase (AST) and various metabolic parameters, C-reactive protein (CRP) and an oxidative stress marker (nitrotyrosine, NT) in subjects without any metabolic abnormalities from a population-based sample.METHODS: Two hundred and five subjects with normal body mass index (BMI), glucose tolerance, and without any metabolic abnormality were studied out of 1339subjects, without known liver diseases, alcohol abuse or use of hepatotoxic drugs, who are representative of the 45-64 aged population of Asti (north-western Italy).RESULTS: In all patients metabolic parameters and hs-CRP levels linearly increase from the lowest to the highest ALT and GGT tertiles, while in subjects without metabolic abnormalities, there is a significant association between fasting glucose, uric acid, waist circumference,hs-CRP, triglyceride values, and GGT levels. In these subjects, male sex, higher hs-CRP and glucose levels are associated with GGT levels in a multiple regression model, after adjustments for multiple confounders.In the same model, median NT levels are significantly associated with the increasing GGT tertile (β = 1.06;95%CI 0.67-1.45), but not with the AST and ALT tertiles.In a multiple regression model, after adjusting for age,sex, BMI, waist, smoking, and alcohol consumption, both NT (β = 0.05; 95%CI 0.02-0.08) and hs-CRP levels (β =0.09; 95%CI 0.03-0.15) are significantly associated with fasting glycemia.CONCLUSION: GGT, an easy, universally standardized and available measurement, could represent an early marker of sub-clinical inflammation and oxidative stress in otherwise healthy individuals. Prospective studies are needed to establish if GGT could predict future diabetes in these subjects.展开更多
Endoscopic cryotherapy is a relatively new thermal ablative modality used for the treatment of neoplastic lesions of the esophagus. It relies on cycles of rapid cooling and thawing to induce tissue destruction with a ...Endoscopic cryotherapy is a relatively new thermal ablative modality used for the treatment of neoplastic lesions of the esophagus. It relies on cycles of rapid cooling and thawing to induce tissue destruction with a cryogen(liquid nitrogen or carbon dioxide) leading to intra and extra-cellular damage. Surgical treatment was once considered the standard therapeutic intervention for neoplastic diseases of the esophagus and is associated with considerable rates of morbidity and mortality. Several trials that evaluated cryotherapy in Barrett's esophagus(BE) associated neoplasia showed reasonable efficacy rates and safety profile. Cryotherapy has also found applications in the treatment of esophageal cancer, both for curative and palliative intent. Cryotherapy has also shown promising results as salvage therapy in cases refractory to radiofrequency ablation treatment. Cryoballoon focal ablation using liquid nitrogen is a novel mode of cryogen delivery which has been used for the treatment of BE with dysplasia and squamous cell carcinoma. Most common side effects of cryotherapy reported in the literature include mild chest discomfort, esophageal strictures and bleeding. In conclusion, cryotherapy is an effective and safe method for the treatment of esophageal neoplastic processes, ranging from early stages of low grade dysplasia to esophageal cancer.展开更多
The distribution and anomalies of rare earth elements(REEs) of granitic regolith were studied in Inner Mongolia and Hainan Island, China. One profile showed slight REE enrichment of an upper layer and no obvious light...The distribution and anomalies of rare earth elements(REEs) of granitic regolith were studied in Inner Mongolia and Hainan Island, China. One profile showed slight REE enrichment of an upper layer and no obvious light REE/heavy REE(LREE/HREE) fractionation(La_N/Yb_N of 0.9). The second profile was significantly enriched in REEs and enriched in LREEs in the upper portion(La_N/Yb_N>1.8). Eu, Ce, and Gd anomalies of the two profiles are different. Slightly negative Eu, Ce, and Gd anomalies in NMG-3-1 indicate slow dissolution of primary minerals and little secondary products; in contrast, a positive Eu anomaly in HN-2 suggests the vegetation cycle may contribute to soil. The Ce anomaly of HN-2 reflects oxidation of Ce and coprecipitation by Fe-and Mn-oxides and organic matter. Correlation between Ce and Gd anomalies in HN-2 suggests Ce and Gd are both influenced by redoxreduction.展开更多
文摘燃气轮机结构紧凑,单位功率重量轻,运行平稳且安全可靠,可以大型化且热效率较高,广泛运用于海上油田,为海上油田生产提供电能、热能。燃气轮机机组滑油系统是其重要组成部分之一,起着润滑、冷却、承载、防蚀、清洁、缓冲等作用,良好的润滑油品质是保证燃气轮机良好运行的重要保障,某海上油田燃气轮机滑油换新仅运行1600h后,取样化验发现滑油旋转氧弹值(RPVOT)(监测标准ASTM D2272)下降明显,指标由1300快速降至207,已不能满足滑油使用性能要求,参考Solar《索拉透平发动机所使用的润滑油的规格说明书》规范要求(NO. ES 9-224),需要更换滑油,滑油使用寿命远远低于设计寿命。本文对该故障进行原因分析排查,发现该燃气轮机组1#轴承气封气连接短节断裂,高温气封气泄漏至齿轮箱,导致滑油高温氧化。由于该故障较为隐蔽,且排查处理困难,通过系统分析并提出改进措施。希望为其他油田同类型设备故障处理提供参考。
基金Supported by a grant: "Progetto di Ricerca Sanitaria Finalizzata,Regione Piemonte, 2003"
文摘AIM: To examine the relationships between γ -glutamyltransferase (GGT), alanine-aminotransferase (ALT),aspartate-aminotransferase (AST) and various metabolic parameters, C-reactive protein (CRP) and an oxidative stress marker (nitrotyrosine, NT) in subjects without any metabolic abnormalities from a population-based sample.METHODS: Two hundred and five subjects with normal body mass index (BMI), glucose tolerance, and without any metabolic abnormality were studied out of 1339subjects, without known liver diseases, alcohol abuse or use of hepatotoxic drugs, who are representative of the 45-64 aged population of Asti (north-western Italy).RESULTS: In all patients metabolic parameters and hs-CRP levels linearly increase from the lowest to the highest ALT and GGT tertiles, while in subjects without metabolic abnormalities, there is a significant association between fasting glucose, uric acid, waist circumference,hs-CRP, triglyceride values, and GGT levels. In these subjects, male sex, higher hs-CRP and glucose levels are associated with GGT levels in a multiple regression model, after adjustments for multiple confounders.In the same model, median NT levels are significantly associated with the increasing GGT tertile (β = 1.06;95%CI 0.67-1.45), but not with the AST and ALT tertiles.In a multiple regression model, after adjusting for age,sex, BMI, waist, smoking, and alcohol consumption, both NT (β = 0.05; 95%CI 0.02-0.08) and hs-CRP levels (β =0.09; 95%CI 0.03-0.15) are significantly associated with fasting glycemia.CONCLUSION: GGT, an easy, universally standardized and available measurement, could represent an early marker of sub-clinical inflammation and oxidative stress in otherwise healthy individuals. Prospective studies are needed to establish if GGT could predict future diabetes in these subjects.
文摘Endoscopic cryotherapy is a relatively new thermal ablative modality used for the treatment of neoplastic lesions of the esophagus. It relies on cycles of rapid cooling and thawing to induce tissue destruction with a cryogen(liquid nitrogen or carbon dioxide) leading to intra and extra-cellular damage. Surgical treatment was once considered the standard therapeutic intervention for neoplastic diseases of the esophagus and is associated with considerable rates of morbidity and mortality. Several trials that evaluated cryotherapy in Barrett's esophagus(BE) associated neoplasia showed reasonable efficacy rates and safety profile. Cryotherapy has also found applications in the treatment of esophageal cancer, both for curative and palliative intent. Cryotherapy has also shown promising results as salvage therapy in cases refractory to radiofrequency ablation treatment. Cryoballoon focal ablation using liquid nitrogen is a novel mode of cryogen delivery which has been used for the treatment of BE with dysplasia and squamous cell carcinoma. Most common side effects of cryotherapy reported in the literature include mild chest discomfort, esophageal strictures and bleeding. In conclusion, cryotherapy is an effective and safe method for the treatment of esophageal neoplastic processes, ranging from early stages of low grade dysplasia to esophageal cancer.
基金supported by the National Natural Science Foundation of China(Grant No.4121000441661144042)National Basic Research Program(973 project)of China(2013CB956401)
文摘The distribution and anomalies of rare earth elements(REEs) of granitic regolith were studied in Inner Mongolia and Hainan Island, China. One profile showed slight REE enrichment of an upper layer and no obvious light REE/heavy REE(LREE/HREE) fractionation(La_N/Yb_N of 0.9). The second profile was significantly enriched in REEs and enriched in LREEs in the upper portion(La_N/Yb_N>1.8). Eu, Ce, and Gd anomalies of the two profiles are different. Slightly negative Eu, Ce, and Gd anomalies in NMG-3-1 indicate slow dissolution of primary minerals and little secondary products; in contrast, a positive Eu anomaly in HN-2 suggests the vegetation cycle may contribute to soil. The Ce anomaly of HN-2 reflects oxidation of Ce and coprecipitation by Fe-and Mn-oxides and organic matter. Correlation between Ce and Gd anomalies in HN-2 suggests Ce and Gd are both influenced by redoxreduction.
