为了提高短期光伏发电的预测精度,减少光伏发电不稳定性对于用户和电网的影响,提出一种结合相似日理论和K-means改进蝙蝠算法优化最小二乘法支持向量机LSSVM(least squares support vector machine)正则化参数和核参数的光伏发电功率短...为了提高短期光伏发电的预测精度,减少光伏发电不稳定性对于用户和电网的影响,提出一种结合相似日理论和K-means改进蝙蝠算法优化最小二乘法支持向量机LSSVM(least squares support vector machine)正则化参数和核参数的光伏发电功率短期预测方法。该方法通过历史数据集和预测日数据分析影响光伏发电功率的因素,构建日特征向量,筛选历史日数据作为训练集,并将预测日数据作为校验集。利用改进的蝙蝠算法全局寻优特性对LSSVM的参数进行优化,构建短期光伏发电功率预测模型。将所提模型与其他智能算法进行比较,结果表明该方法预测精度较高。展开更多
Background Glucosylceramide synthase （GCS）,an enzyme responsible for ceramide glycosylation,plays an important role in multidrug resistance （MDR） in some tumors in vitro; however,its expression and clinicopatholog...Background Glucosylceramide synthase （GCS）,an enzyme responsible for ceramide glycosylation,plays an important role in multidrug resistance （MDR） in some tumors in vitro; however,its expression and clinicopathological significance in non-small cell lung cancer （NSCLC） remains unclear.Methods We evaluated GCS expression in 116 paired tumor and adjacent non-cancerous tissues and 50 frozen tissues from patients with NSCLC using immunohistochemistry and western blotting,and explored the correlation between GCS and NSCLC clinicopathological characteristics and prognosis.We observed the association between GCS and the MDR proteins P-glycoprotein （P-gp） and lung resistance-related protein （LRP） to determine the link between GCS and MDR at the histological level.Results GCS expression was significantly upregulated in NSCLC tumors compared with non-cancerous tissue.There was high GCS expression in 75/116 tumor specimens （64.7％） and 16/116 non-cancerous specimens （13.8％）.High GCS expression was significantly associated with poor differentiation （P=0.01）,lymph node metastasis （P=0.004）,recurrence/ distant metastasis （P=0.006）,and chemotherapy resistance （P=0.025）.Multivariate analysis demonstrated that GCS immunopositivity was an independent risk factor for survival （P=0.018）.P-gp was expressed in 80/116 tumors （69.0％） and in 12/116 non-cancerous tissue specimens （10.3％; P=0.001）; LRP was expressed in 85/116 tumors （73.3％） and 19/116 non-cancerous tissue specimens （16.4％; P=0.001）.Importantly,the results demonstrated that increased GCS expression in NSCLC cancer specimens correlated with increased expression of P-gp and LRP,molecules known to stimulate cancer cell MDR （r=0.612 and 0.503,P=0.01 and 0.035,respectively）.Conclusion GCS upregulation might contribute to the development of NSCLC and could be a useful prognostic indicator and chemoresistance predictor for NSCLC patients.展开更多
文摘为了提高短期光伏发电的预测精度,减少光伏发电不稳定性对于用户和电网的影响,提出一种结合相似日理论和K-means改进蝙蝠算法优化最小二乘法支持向量机LSSVM(least squares support vector machine)正则化参数和核参数的光伏发电功率短期预测方法。该方法通过历史数据集和预测日数据分析影响光伏发电功率的因素,构建日特征向量,筛选历史日数据作为训练集,并将预测日数据作为校验集。利用改进的蝙蝠算法全局寻优特性对LSSVM的参数进行优化,构建短期光伏发电功率预测模型。将所提模型与其他智能算法进行比较,结果表明该方法预测精度较高。
文摘Background Glucosylceramide synthase （GCS）,an enzyme responsible for ceramide glycosylation,plays an important role in multidrug resistance （MDR） in some tumors in vitro; however,its expression and clinicopathological significance in non-small cell lung cancer （NSCLC） remains unclear.Methods We evaluated GCS expression in 116 paired tumor and adjacent non-cancerous tissues and 50 frozen tissues from patients with NSCLC using immunohistochemistry and western blotting,and explored the correlation between GCS and NSCLC clinicopathological characteristics and prognosis.We observed the association between GCS and the MDR proteins P-glycoprotein （P-gp） and lung resistance-related protein （LRP） to determine the link between GCS and MDR at the histological level.Results GCS expression was significantly upregulated in NSCLC tumors compared with non-cancerous tissue.There was high GCS expression in 75/116 tumor specimens （64.7％） and 16/116 non-cancerous specimens （13.8％）.High GCS expression was significantly associated with poor differentiation （P=0.01）,lymph node metastasis （P=0.004）,recurrence/ distant metastasis （P=0.006）,and chemotherapy resistance （P=0.025）.Multivariate analysis demonstrated that GCS immunopositivity was an independent risk factor for survival （P=0.018）.P-gp was expressed in 80/116 tumors （69.0％） and in 12/116 non-cancerous tissue specimens （10.3％; P=0.001）; LRP was expressed in 85/116 tumors （73.3％） and 19/116 non-cancerous tissue specimens （16.4％; P=0.001）.Importantly,the results demonstrated that increased GCS expression in NSCLC cancer specimens correlated with increased expression of P-gp and LRP,molecules known to stimulate cancer cell MDR （r=0.612 and 0.503,P=0.01 and 0.035,respectively）.Conclusion GCS upregulation might contribute to the development of NSCLC and could be a useful prognostic indicator and chemoresistance predictor for NSCLC patients.
