The performance of the graph-based scheduling for device-to-device communications overlaying cellular networks is studied. The graph-based scheduling consists of two stages, the frequency assignment stage and the time...The performance of the graph-based scheduling for device-to-device communications overlaying cellular networks is studied. The graph-based scheduling consists of two stages, the frequency assignment stage and the time slot scheduling stage. For such scheduling, a theoretical method to analyze the average spectrum efficiency of the D2D subsystem is proposed. The method consists of three steps. First, the frequency assignment stage is analyzed and the approximate formula of the average number of the D2D links which are assigned the same frequency is derived. Secondly, the time slot scheduling stage is analyzed and the approximate formula of the average probability of a D2D link being scheduled in a time slot is derived. Thirdly, the average spectrum efficiency of the D2D subsystem is analyzed and the corresponding approximate formula is derived. Analysis results show that the average spectrum efficiency of the D2D subsystem is approximately inversely linearly proportional to the second- order origin moment of the normalized broadcast radius of D2D links. Simulation results show that the proposed method can correctly predict the average spectrum efficiency of the D2D subsystem.展开更多
目的分析2型糖尿病患者25-羟维生素D[25(OH)D]水平,初步了解血清25(OH)D水平与2型糖尿病患者糖化血红蛋白(HbA1c)、胰岛功能等代谢指标的相关性。方法选择新乡市第一人民医院内分泌科2020年1月至2020年12月收治的459例2型糖尿病患者为...目的分析2型糖尿病患者25-羟维生素D[25(OH)D]水平,初步了解血清25(OH)D水平与2型糖尿病患者糖化血红蛋白(HbA1c)、胰岛功能等代谢指标的相关性。方法选择新乡市第一人民医院内分泌科2020年1月至2020年12月收治的459例2型糖尿病患者为研究对象。收集患者的临床资料,包括性别、年龄、血清25(OH)D、空腹胰岛素、C肽、HbA1c、空腹血糖、餐后血糖、尿微量白蛋白、尿白蛋白肌酐比值、血钙、血尿酸(UA)、三酰甘油(TG)、总胆固醇(TCH)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)等。根据血清25(OH)D水平将患者分为充足组[n=20,25(OH)D≥30μg·L^(-1)]、不足组[n=95,20μg·L^(-1)≤25(OH)D<30μg·L^(-1)]、缺乏组[n=231,10μg·L^(-1)≤25(OH)D<20μg·L^(-1)]、严重缺乏组[n=113,25(OH)D<10μg·L^(-1)]。比较4组患者各代谢指标的差异,采用Pearson相关分析25(OH)D与各代谢指标的相关性。结果2型糖尿病患者血清25(OH)D水平为3.00~46.59(15.75±0.35)μg·L^(-1),男性患者的血清25(OH)D水平显著高于女性患者(P<0.05)。2型糖尿病患者25(OH)D缺乏的患病率为74.9%(344/459),25(OH)D缺乏主要发生在1、2、3、4、11、12月份。不足组、缺乏组和严重缺乏组患者HbA1c显著高于充足组(P<0.05),缺乏组和严重缺乏组患者HbA1c显著高于不足组(P<0.05);缺乏组和严重缺乏组患者HbA1c比较差异无统计学意义(P>0.05)。充足组与不足组、缺乏组与严重缺乏组患者空腹血糖比较差异无统计学意义(P>0.05);缺乏组和严重缺乏组患者空腹血糖显著高于充足组、不足组(P<0.05)。充足组、不足组、缺乏组患者空腹胰岛素、尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值比较差异无统计学意义(P>0.05);严重缺乏组患者空腹胰岛素显著低于充足组、不足组和缺乏组,尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值显著高于充足组、不足组和缺乏组(P<0.05)。4组患者的稳态模型评估的胰岛素抵抗指数(HOMA-IR)、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙比较差异均无统计学意义(P>0.05)。Pearson相关性分析结果显示,2型糖尿病患者血清25(OH)D水平与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关(r=-0.093、-0.166、-0.157,P<0.05),与空腹胰岛素呈正相关(r=0.089,P<0.05)。2型糖尿病患者血清25(OH)D水平与空腹血糖、HOMA-IR、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙等无相关性(P>0.05)。结论2型糖尿病患者25(OH)D缺乏与不足普遍存在,女性患者缺乏更明显。2型糖尿病患者25(OH)D水平与空腹胰岛素呈正相关,与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关,25(OH)D缺乏的2型糖尿病患者主要分布在1、2、3、4、11、12月份。展开更多
基金The National Natural Science Foundation of China(No.61571111)the National High Technology Research and Development Program of China(863 Program)(No.2014AA01A703,2015AA01A706)the Fundamental Research Funds for the Central Universities of China(No.2242016K40098)
文摘The performance of the graph-based scheduling for device-to-device communications overlaying cellular networks is studied. The graph-based scheduling consists of two stages, the frequency assignment stage and the time slot scheduling stage. For such scheduling, a theoretical method to analyze the average spectrum efficiency of the D2D subsystem is proposed. The method consists of three steps. First, the frequency assignment stage is analyzed and the approximate formula of the average number of the D2D links which are assigned the same frequency is derived. Secondly, the time slot scheduling stage is analyzed and the approximate formula of the average probability of a D2D link being scheduled in a time slot is derived. Thirdly, the average spectrum efficiency of the D2D subsystem is analyzed and the corresponding approximate formula is derived. Analysis results show that the average spectrum efficiency of the D2D subsystem is approximately inversely linearly proportional to the second- order origin moment of the normalized broadcast radius of D2D links. Simulation results show that the proposed method can correctly predict the average spectrum efficiency of the D2D subsystem.
文摘目的分析2型糖尿病患者25-羟维生素D[25(OH)D]水平,初步了解血清25(OH)D水平与2型糖尿病患者糖化血红蛋白(HbA1c)、胰岛功能等代谢指标的相关性。方法选择新乡市第一人民医院内分泌科2020年1月至2020年12月收治的459例2型糖尿病患者为研究对象。收集患者的临床资料,包括性别、年龄、血清25(OH)D、空腹胰岛素、C肽、HbA1c、空腹血糖、餐后血糖、尿微量白蛋白、尿白蛋白肌酐比值、血钙、血尿酸(UA)、三酰甘油(TG)、总胆固醇(TCH)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)等。根据血清25(OH)D水平将患者分为充足组[n=20,25(OH)D≥30μg·L^(-1)]、不足组[n=95,20μg·L^(-1)≤25(OH)D<30μg·L^(-1)]、缺乏组[n=231,10μg·L^(-1)≤25(OH)D<20μg·L^(-1)]、严重缺乏组[n=113,25(OH)D<10μg·L^(-1)]。比较4组患者各代谢指标的差异,采用Pearson相关分析25(OH)D与各代谢指标的相关性。结果2型糖尿病患者血清25(OH)D水平为3.00~46.59(15.75±0.35)μg·L^(-1),男性患者的血清25(OH)D水平显著高于女性患者(P<0.05)。2型糖尿病患者25(OH)D缺乏的患病率为74.9%(344/459),25(OH)D缺乏主要发生在1、2、3、4、11、12月份。不足组、缺乏组和严重缺乏组患者HbA1c显著高于充足组(P<0.05),缺乏组和严重缺乏组患者HbA1c显著高于不足组(P<0.05);缺乏组和严重缺乏组患者HbA1c比较差异无统计学意义(P>0.05)。充足组与不足组、缺乏组与严重缺乏组患者空腹血糖比较差异无统计学意义(P>0.05);缺乏组和严重缺乏组患者空腹血糖显著高于充足组、不足组(P<0.05)。充足组、不足组、缺乏组患者空腹胰岛素、尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值比较差异无统计学意义(P>0.05);严重缺乏组患者空腹胰岛素显著低于充足组、不足组和缺乏组,尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值显著高于充足组、不足组和缺乏组(P<0.05)。4组患者的稳态模型评估的胰岛素抵抗指数(HOMA-IR)、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙比较差异均无统计学意义(P>0.05)。Pearson相关性分析结果显示,2型糖尿病患者血清25(OH)D水平与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关(r=-0.093、-0.166、-0.157,P<0.05),与空腹胰岛素呈正相关(r=0.089,P<0.05)。2型糖尿病患者血清25(OH)D水平与空腹血糖、HOMA-IR、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙等无相关性(P>0.05)。结论2型糖尿病患者25(OH)D缺乏与不足普遍存在,女性患者缺乏更明显。2型糖尿病患者25(OH)D水平与空腹胰岛素呈正相关,与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关,25(OH)D缺乏的2型糖尿病患者主要分布在1、2、3、4、11、12月份。
