CO_2和CF_4气体物理化学性能稳定,液化温度低,灭弧能力强,作为潜在的SF_6替代气体引起了广泛的关注。断路器开断故障电弧过程中的喷口压力特性对气体灭弧性能和断路器结构的优化设计等都具有重要意义。为此基于一台126 k V压气式断路器...CO_2和CF_4气体物理化学性能稳定,液化温度低,灭弧能力强,作为潜在的SF_6替代气体引起了广泛的关注。断路器开断故障电弧过程中的喷口压力特性对气体灭弧性能和断路器结构的优化设计等都具有重要意义。为此基于一台126 k V压气式断路器模型,通过实验研究了不同体积分数混合比例下SF_6-CO_2和SF_6-CF_4混合气体中灭弧室喷口压力的变化特性。结果表明,SF_6-CF_4混合气体的喷口监测点压力增幅Δppeak和电流零点时刻的压力增量ΔpCZ均明显高于SF_6-CO_2混合气体,气吹电弧作用更强;两种混合气体测量点处的压力增幅Δppeak均随SF_6体积分数增加而增大,SF_6-CO_2混合气体电流零点处的压力增量ΔpCZ随SF_6体积分数增加也明显增大,而SF_6-CF_4混合气体ΔpCZ的变化较小;此外,喷口压力的建立情况对断路器热开断能力有较为重要的作用。展开更多
BACKGROUND Gastric cancer ranks among the leading malignancies worldwide,noted for its high morbidity and mortality,and remains a significant challenge to global public health.AIM To investigate the association betwee...BACKGROUND Gastric cancer ranks among the leading malignancies worldwide,noted for its high morbidity and mortality,and remains a significant challenge to global public health.AIM To investigate the association between the expression of splicing factor 3b subunit 4(SF3B4)and high mobility group box 1(HMGB1)with the clinical characteristics and prognostic outcomes of gastric cancer patients.METHODS A retrospective cohort study was conducted involving 114 individuals diagnosed with gastric cancer and admitted to our institution from January 2020 to December 2021.A comparison group of 90 patients diagnosed with benign gastric disorders during the same period was also included.Expression levels of SF3B4 and HMGB1 were assessed using real-time quantitative polymerase chain reaction.Expression patterns were analyzed in relation to various clinicopathological features.Receiver operating characteristic curves were constructed to evaluate the ability of SF3B4 and HMGB1,alone and in combination,to predict unfavorable one-year outcomes.Multivariate logistic regression was utilized to identify independent predictors of mortality.Kaplan-Meier survival curves were generated to examine survival differences based on SF3B4 and HMGB1 expression levels.RESULTS Both SF3B4 and HMGB1 were markedly upregulated in tumor tissues of gastric cancer patients compared to adjacent normal tissues and to tissues from nonmalignant gastric disease patients(^(a)P<0.05).Higher expression levels of these two genes were significantly associated with aggressive pathological features,including poor differentiation,tumor size>5 cm,deep infiltration(T3-T4),lymph node involvement,and advanced clinical stage(III–IV)(^(a)P<0.05).Receiver operating characteristic analysis revealed that the combined use of SF3B4 and HMGB1 yielded an area under the curve of 0.914,surpassing the predictive performance of either marker alone(SF3B4:0.776;HMGB1:0.757).Multivariate analysis identified SF3B4≥1.45,HMGB1≥0.93,poor differentiation,larger tumor size,deeper invasion,lymph node metastasis,and advanced clinical tumor-node-metastasis staging as independent factors contributing to one-year mortality(^(a)P<0.05).Survival analysis indicated that patients with elevated SF3B4 and HMGB1 levels had a shorter median survival(25.74±5.46 months)compared to those with lower expression levels(33.29±6.71 months,log-rank=10.534,^(a)P<0.05).CONCLUSION Elevated SF3B4 and HMGB1 expression in gastric cancer tissue is significantly associated with tumor aggressiveness,worse prognosis,and reduced survival.These biomarkers may offer clinical value in stratifying patients by risk and in forecasting outcomes.Their combined assessment improves predictive accuracy for poor prognosis and may serve as a more effective tool than individual evaluation.展开更多
文摘CO_2和CF_4气体物理化学性能稳定,液化温度低,灭弧能力强,作为潜在的SF_6替代气体引起了广泛的关注。断路器开断故障电弧过程中的喷口压力特性对气体灭弧性能和断路器结构的优化设计等都具有重要意义。为此基于一台126 k V压气式断路器模型,通过实验研究了不同体积分数混合比例下SF_6-CO_2和SF_6-CF_4混合气体中灭弧室喷口压力的变化特性。结果表明,SF_6-CF_4混合气体的喷口监测点压力增幅Δppeak和电流零点时刻的压力增量ΔpCZ均明显高于SF_6-CO_2混合气体,气吹电弧作用更强;两种混合气体测量点处的压力增幅Δppeak均随SF_6体积分数增加而增大,SF_6-CO_2混合气体电流零点处的压力增量ΔpCZ随SF_6体积分数增加也明显增大,而SF_6-CF_4混合气体ΔpCZ的变化较小;此外,喷口压力的建立情况对断路器热开断能力有较为重要的作用。
文摘BACKGROUND Gastric cancer ranks among the leading malignancies worldwide,noted for its high morbidity and mortality,and remains a significant challenge to global public health.AIM To investigate the association between the expression of splicing factor 3b subunit 4(SF3B4)and high mobility group box 1(HMGB1)with the clinical characteristics and prognostic outcomes of gastric cancer patients.METHODS A retrospective cohort study was conducted involving 114 individuals diagnosed with gastric cancer and admitted to our institution from January 2020 to December 2021.A comparison group of 90 patients diagnosed with benign gastric disorders during the same period was also included.Expression levels of SF3B4 and HMGB1 were assessed using real-time quantitative polymerase chain reaction.Expression patterns were analyzed in relation to various clinicopathological features.Receiver operating characteristic curves were constructed to evaluate the ability of SF3B4 and HMGB1,alone and in combination,to predict unfavorable one-year outcomes.Multivariate logistic regression was utilized to identify independent predictors of mortality.Kaplan-Meier survival curves were generated to examine survival differences based on SF3B4 and HMGB1 expression levels.RESULTS Both SF3B4 and HMGB1 were markedly upregulated in tumor tissues of gastric cancer patients compared to adjacent normal tissues and to tissues from nonmalignant gastric disease patients(^(a)P<0.05).Higher expression levels of these two genes were significantly associated with aggressive pathological features,including poor differentiation,tumor size>5 cm,deep infiltration(T3-T4),lymph node involvement,and advanced clinical stage(III–IV)(^(a)P<0.05).Receiver operating characteristic analysis revealed that the combined use of SF3B4 and HMGB1 yielded an area under the curve of 0.914,surpassing the predictive performance of either marker alone(SF3B4:0.776;HMGB1:0.757).Multivariate analysis identified SF3B4≥1.45,HMGB1≥0.93,poor differentiation,larger tumor size,deeper invasion,lymph node metastasis,and advanced clinical tumor-node-metastasis staging as independent factors contributing to one-year mortality(^(a)P<0.05).Survival analysis indicated that patients with elevated SF3B4 and HMGB1 levels had a shorter median survival(25.74±5.46 months)compared to those with lower expression levels(33.29±6.71 months,log-rank=10.534,^(a)P<0.05).CONCLUSION Elevated SF3B4 and HMGB1 expression in gastric cancer tissue is significantly associated with tumor aggressiveness,worse prognosis,and reduced survival.These biomarkers may offer clinical value in stratifying patients by risk and in forecasting outcomes.Their combined assessment improves predictive accuracy for poor prognosis and may serve as a more effective tool than individual evaluation.
