The disk-jet symbiosis is a fundamental problem in our understanding of the Active Galactic Nuclei （AGN）. We explore the relation between the Doppler factors d of the jet of blazars and their broad line region lumin...The disk-jet symbiosis is a fundamental problem in our understanding of the Active Galactic Nuclei （AGN）. We explore the relation between the Doppler factors d of the jet of blazars and their broad line region luminosity LBLR. Since different methods measuring δ might differ substantially, we use data obtained from 3 independent methods and compile 3 samples of sources for each of them, respectively. Two samples consist of blazars, that is, Flat Spectrum Radio Quasars （FSRQs） and BL Lacertae objects （BL Lacs）, and the other consists of BL Lacs. dis one of the most important jet properties and LBLR is thought to be the proxy of the accretion power. Correlation analysis to these samples shows that there exists a significant correlation between δ and LBLR, which supports the idea that the jet powering process is closely linked with the accretion process and provides new evidence for disk-jet connection. Furthermore, the results are consistent with the idea that the Blandford-Znajek mechanism is sufficient for BL Lacs and a hybrid model is needed for FSRQs.展开更多
[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new ...[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new generation weather radar in Harbin from 2002 to 2007, the features of the reflectivity factors of the cold front cloud system were summarized. [Result] The cloud formed by the cold front was in banded form in general. However, there was void in the cloud and its intensity was uneven. Most fast moving cold front was long and narrow banded echo and basically the radial velocity turned from northwest wind to southwest. With the changes of month, the feature of the reflective rate also changed. In winter, the cold front cloud was in layer form. The feature of the reflectivity factors was weak and in large area. However, the structure was loose and there was space in the echo. Among them, there were several strong echoes. Strong convection cell echo formed in the two sides of the cold front, and it moved with the entire cloud belt. When the dry cold front moved, regional strong convective current formed, mainly by convective cloud and small echo area. Generally, the changes of the wind direction can not be expounded from the radial velocity. However, the intensity of the convection cell was distinct, 'three-body scattering', 'side lobe echo', and 'weak echo', as well as features of super convection cell. [Conclusion] The study provided positive role for the application of Doppler radar in the surveillance of weather in Heilongjiang Province.展开更多
目的:探究产前彩色多普勒超声评估胎儿生长受限(FGR)的价值,分析超声诊断假阴性的影响因素。方法:选择2019年10月至2023年7月于我院行产前彩色多普勒超声诊断为FGR并获得产后随访确诊的118例胎儿作为FGR真阳性组,60例产前彩色多普勒超...目的:探究产前彩色多普勒超声评估胎儿生长受限(FGR)的价值,分析超声诊断假阴性的影响因素。方法:选择2019年10月至2023年7月于我院行产前彩色多普勒超声诊断为FGR并获得产后随访确诊的118例胎儿作为FGR真阳性组,60例产前彩色多普勒超声诊断为FGR阴性而产后确诊为FGR的胎儿作为FGR假阴性组。比较首次检查时两组间不同孕周的超声参数;比较两组胎儿的临床资料,采用随机森林算法及多因素Logistic回归分析筛选影响超声诊断FGR假阴性的因素;构建多因素Logistic回归模型并评价其预测效能。结果:孕12~14周假阴性组胎儿的腹围、股骨长明显长于真阳性组,血流收缩末期峰值(S)/舒张末期峰值(D)明显低于真阳性组(P<0.05);孕15~27周假阴性组胎儿的腹围、股骨长明显长于真阳性组(P<0.05);孕28~37周假阴性组胎儿的腹围明显长于真阳性组(P<0.05);随机森林算法及多因素Logistic回归分析结果显示,孕期增重高于标准、妊娠糖尿病、胎方位为臀位、分娩胎龄>40周、胎儿性别为男性、腹围增加是影响超声诊断FGR假阴性的危险因素(P<0.05);当模型预测超声诊断FGR假阴性概率为0.85时,约登指数最大(74.46),敏感度为86.45%,特异度为88.01%,逻辑回归拟合优度检验结果显示模型Bootstrap验证前后的Nagelkerke R 2=0.602。结论:随着孕周的增加(12~37周),首次超声检查诊断FGR真阳性和假阴性胎儿间存在显著差异的指标数量逐渐减少,孕期增重、妊娠糖尿病、胎方位等是影响超声诊断FGR假阴性的危险因素。展开更多
目的探讨彩色多普勒超声联合血清神经元特异性烯醇化酶(neuron-specific enolase,NSE)及5 min Apgar评分对新生儿颅内出血(intracranial hemorrhage,ICH)的诊断价值及影响ICH发生的危险因素。方法选取2019年2月至2021年3月承德市中心医...目的探讨彩色多普勒超声联合血清神经元特异性烯醇化酶(neuron-specific enolase,NSE)及5 min Apgar评分对新生儿颅内出血(intracranial hemorrhage,ICH)的诊断价值及影响ICH发生的危险因素。方法选取2019年2月至2021年3月承德市中心医院新生儿科收治的存在颅脑损伤危险因素的253例新生儿为研究对象,均接受彩色多普勒超声检查,根据是否存在ICH分为ICH组(n=99)和无ICH组(n=154)。观察并比较两组彩色多普勒超声参数[收缩期峰值流速(peak systolicvelocity,PSV)、阻力指数(resistance index,RI)、舒张末期流速(end diastolic velocity,EDV)]、血清NSE水平、5 min Apgar评分情况,分析血清NSE水平、Apgar评分与彩色多普勒超声参数的相关性及三者联合检测对新生儿ICH的诊断价值,并分析ICH发生的主要影响因素。统计学方法采用独立样本t检验、χ^(2)检验、Pearson相关性分析、Logistic回归分析及受试者操作特征(receiver operating characteristic,ROC)曲线分析。结果ICH组与无ICH组PSV[(6.4±1.2)cm/s与(10.1±1.4)cm/s,t=21.628]、RI(0.6±0.1与0.7±0.1,t=8.144)、EDV[(2.5±0.4)cm/s与(3.1±0.4)cm/s,t=13.216]以及5 min Apgar评分[(6.5±1.7)分与(8.8±1.0)分,t=13.308]比较,ICH组均显著低于无ICH组(P值均<0.001);血清NSE水平显著高于无ICH组[(149.1±10.6)μg/L与(95.2±10.4)μg/L,t=40.015,P<0.001]。ICH组血清NSE水平与彩色多普勒超声参数PSV、RI、EDV呈负相关(r值分为-0.573、-0.520、-0.536,P值均<0.05);5 min Apgar评分与彩色多普勒超声参数PSV、RI、EDV呈正相关(r值分别为0.601、0.529、0.505,P值均<0.05)。ROC曲线结果发现,彩色多普勒超声、血清NSE水平、5 min Apgar评分联合诊断新生儿ICH的曲线下面积(area under the curve,AUC)最大,为0.861。单因素分析显示,与无ICH组比较,ICH组患儿的胎龄更小,出生体质量、5 min Apgar评分更低,出生窒息、应用多巴胺、应用机械通气比例及血清NSE水平更高,差异有统计学意义(P值均<0.05)。多因素Logistic回归分析结果显示,胎龄<32周、出生体质量<1500 g、血清NSE水平>117.95μg/L、5 min Apgar评分<7分是诱发ICH的独立危险因素。结论彩色多普勒超声联合血清NSE及5 min Apgar评分可提高ICH的诊断价值;胎龄<32周、出生体质量<1500 g、血清NSE水平>117.95μg/L、5 min Apgar评分<7分是诱发ICH的独立危险因素。展开更多
目的探究多囊卵巢综合征(PCOS)患者多普勒超声测量参数与其性激素、炎性因子水平的相关性。方法选择PCOS患者120例(病例组),年龄23~35岁,平均年龄30.69岁。另取同期在医院体检健康女性100例(对照组),年龄22~35岁,平均年龄30.25岁。给予...目的探究多囊卵巢综合征(PCOS)患者多普勒超声测量参数与其性激素、炎性因子水平的相关性。方法选择PCOS患者120例(病例组),年龄23~35岁,平均年龄30.69岁。另取同期在医院体检健康女性100例(对照组),年龄22~35岁,平均年龄30.25岁。给予两组多普勒超声检查,测量两组子宫、卵巢血流参数[阻力指数(RI)、搏动指数(PI)],并取肘静脉血检测其性激素[雌二醇(E2)、促卵泡激素(FSH)、促黄体生成素(LH)、睾酮(T)]及炎性因子[肿瘤坏死因子(TNF)-α、白细胞介素6(IL-6)、内皮抑素(ES)]水平,分析PCOS患者多普勒超声血流参数与其血清炎性因子、性激素水平的相关性。结果两组超声参数比较,病例组子宫RI、PI显著高于对照组(0.89±0.14 vs 0.81±0.12、2.87±0.26 vs2.14±0.21。P<0.05),卵巢RI、PI显著低于对照组(0.43±0.07 vs 0.62±0.12、0.73±0.11 vs 0.91±0.14。P<0.05)。病例组血清LH、T水平显著高于对照组[(9.33±1.64)U/L vs(4.59±1.02)U/L、(1.14±0.13)ng/mL vs(0.61±0.08)ng/mL。P<0.05],FSH水平显著低于对照组[(6.31±1.02)U/L vs(8.96±1.28)U/L。P<0.05],E2水平差异无统计学意义(P>0.05)。病例组血清TNF-α、IL-6、ES均显著高于对照组[(20.95±3.05)ng/mL vs(12.52±2.51)ng/mL、(12.54±1.57)ng/mL vs(6.33±1.05)pg/mL、(234.25±16.33)μg/L vs(156.97±17.05)μg/L。P<0.05]。PCOS患者子宫RI、PI与患者LH、T水平正相关(r=0.531、0.433、0.371、0.407,均P<0.05),与FSH水平负相关(r=-0.963、-1.081,P<0.05);卵巢RI、PI与患者血清LH、T水平负相关(r=-2.082、-1.214、-1.530、-1.094,均P<0.05),与FSH水平正相关(r=0.392、0.583,均P<0.05);PCOS患者子宫RI、PI与血清TNF-α、IL-6、ES均为正相关(r=0.364、0.561、0.385、0.269、0.312、0.405,均P<0.05),卵巢RI、PI与血清TNF-α、IL-6、ES均为负相关(r=-2.634、-3.397、-1.482、-0.398、-1.433、-2.317,均P<0.05)。结论PCOS患者普遍存在子宫及卵巢血流动力学异常,并伴有炎性因子及部分性激素水平高表达,其子宫、卵巢多普勒超声参数与性激素、炎性因子水平具有相关性。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10973034,10978019,11043002)the State Key Development Program for Basic Research of China(Grant No. 2009CB824800)the Provincial Natural Science Foundation of Yunnan (Grant No.09401145,1012456)
文摘The disk-jet symbiosis is a fundamental problem in our understanding of the Active Galactic Nuclei （AGN）. We explore the relation between the Doppler factors d of the jet of blazars and their broad line region luminosity LBLR. Since different methods measuring δ might differ substantially, we use data obtained from 3 independent methods and compile 3 samples of sources for each of them, respectively. Two samples consist of blazars, that is, Flat Spectrum Radio Quasars （FSRQs） and BL Lacertae objects （BL Lacs）, and the other consists of BL Lacs. dis one of the most important jet properties and LBLR is thought to be the proxy of the accretion power. Correlation analysis to these samples shows that there exists a significant correlation between δ and LBLR, which supports the idea that the jet powering process is closely linked with the accretion process and provides new evidence for disk-jet connection. Furthermore, the results are consistent with the idea that the Blandford-Znajek mechanism is sufficient for BL Lacs and a hybrid model is needed for FSRQs.
文摘[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new generation weather radar in Harbin from 2002 to 2007, the features of the reflectivity factors of the cold front cloud system were summarized. [Result] The cloud formed by the cold front was in banded form in general. However, there was void in the cloud and its intensity was uneven. Most fast moving cold front was long and narrow banded echo and basically the radial velocity turned from northwest wind to southwest. With the changes of month, the feature of the reflective rate also changed. In winter, the cold front cloud was in layer form. The feature of the reflectivity factors was weak and in large area. However, the structure was loose and there was space in the echo. Among them, there were several strong echoes. Strong convection cell echo formed in the two sides of the cold front, and it moved with the entire cloud belt. When the dry cold front moved, regional strong convective current formed, mainly by convective cloud and small echo area. Generally, the changes of the wind direction can not be expounded from the radial velocity. However, the intensity of the convection cell was distinct, 'three-body scattering', 'side lobe echo', and 'weak echo', as well as features of super convection cell. [Conclusion] The study provided positive role for the application of Doppler radar in the surveillance of weather in Heilongjiang Province.
文摘目的:探究产前彩色多普勒超声评估胎儿生长受限(FGR)的价值,分析超声诊断假阴性的影响因素。方法:选择2019年10月至2023年7月于我院行产前彩色多普勒超声诊断为FGR并获得产后随访确诊的118例胎儿作为FGR真阳性组,60例产前彩色多普勒超声诊断为FGR阴性而产后确诊为FGR的胎儿作为FGR假阴性组。比较首次检查时两组间不同孕周的超声参数;比较两组胎儿的临床资料,采用随机森林算法及多因素Logistic回归分析筛选影响超声诊断FGR假阴性的因素;构建多因素Logistic回归模型并评价其预测效能。结果:孕12~14周假阴性组胎儿的腹围、股骨长明显长于真阳性组,血流收缩末期峰值(S)/舒张末期峰值(D)明显低于真阳性组(P<0.05);孕15~27周假阴性组胎儿的腹围、股骨长明显长于真阳性组(P<0.05);孕28~37周假阴性组胎儿的腹围明显长于真阳性组(P<0.05);随机森林算法及多因素Logistic回归分析结果显示,孕期增重高于标准、妊娠糖尿病、胎方位为臀位、分娩胎龄>40周、胎儿性别为男性、腹围增加是影响超声诊断FGR假阴性的危险因素(P<0.05);当模型预测超声诊断FGR假阴性概率为0.85时,约登指数最大(74.46),敏感度为86.45%,特异度为88.01%,逻辑回归拟合优度检验结果显示模型Bootstrap验证前后的Nagelkerke R 2=0.602。结论:随着孕周的增加(12~37周),首次超声检查诊断FGR真阳性和假阴性胎儿间存在显著差异的指标数量逐渐减少,孕期增重、妊娠糖尿病、胎方位等是影响超声诊断FGR假阴性的危险因素。
文摘目的探讨彩色多普勒超声联合血清神经元特异性烯醇化酶(neuron-specific enolase,NSE)及5 min Apgar评分对新生儿颅内出血(intracranial hemorrhage,ICH)的诊断价值及影响ICH发生的危险因素。方法选取2019年2月至2021年3月承德市中心医院新生儿科收治的存在颅脑损伤危险因素的253例新生儿为研究对象,均接受彩色多普勒超声检查,根据是否存在ICH分为ICH组(n=99)和无ICH组(n=154)。观察并比较两组彩色多普勒超声参数[收缩期峰值流速(peak systolicvelocity,PSV)、阻力指数(resistance index,RI)、舒张末期流速(end diastolic velocity,EDV)]、血清NSE水平、5 min Apgar评分情况,分析血清NSE水平、Apgar评分与彩色多普勒超声参数的相关性及三者联合检测对新生儿ICH的诊断价值,并分析ICH发生的主要影响因素。统计学方法采用独立样本t检验、χ^(2)检验、Pearson相关性分析、Logistic回归分析及受试者操作特征(receiver operating characteristic,ROC)曲线分析。结果ICH组与无ICH组PSV[(6.4±1.2)cm/s与(10.1±1.4)cm/s,t=21.628]、RI(0.6±0.1与0.7±0.1,t=8.144)、EDV[(2.5±0.4)cm/s与(3.1±0.4)cm/s,t=13.216]以及5 min Apgar评分[(6.5±1.7)分与(8.8±1.0)分,t=13.308]比较,ICH组均显著低于无ICH组(P值均<0.001);血清NSE水平显著高于无ICH组[(149.1±10.6)μg/L与(95.2±10.4)μg/L,t=40.015,P<0.001]。ICH组血清NSE水平与彩色多普勒超声参数PSV、RI、EDV呈负相关(r值分为-0.573、-0.520、-0.536,P值均<0.05);5 min Apgar评分与彩色多普勒超声参数PSV、RI、EDV呈正相关(r值分别为0.601、0.529、0.505,P值均<0.05)。ROC曲线结果发现,彩色多普勒超声、血清NSE水平、5 min Apgar评分联合诊断新生儿ICH的曲线下面积(area under the curve,AUC)最大,为0.861。单因素分析显示,与无ICH组比较,ICH组患儿的胎龄更小,出生体质量、5 min Apgar评分更低,出生窒息、应用多巴胺、应用机械通气比例及血清NSE水平更高,差异有统计学意义(P值均<0.05)。多因素Logistic回归分析结果显示,胎龄<32周、出生体质量<1500 g、血清NSE水平>117.95μg/L、5 min Apgar评分<7分是诱发ICH的独立危险因素。结论彩色多普勒超声联合血清NSE及5 min Apgar评分可提高ICH的诊断价值;胎龄<32周、出生体质量<1500 g、血清NSE水平>117.95μg/L、5 min Apgar评分<7分是诱发ICH的独立危险因素。
文摘目的探究多囊卵巢综合征(PCOS)患者多普勒超声测量参数与其性激素、炎性因子水平的相关性。方法选择PCOS患者120例(病例组),年龄23~35岁,平均年龄30.69岁。另取同期在医院体检健康女性100例(对照组),年龄22~35岁,平均年龄30.25岁。给予两组多普勒超声检查,测量两组子宫、卵巢血流参数[阻力指数(RI)、搏动指数(PI)],并取肘静脉血检测其性激素[雌二醇(E2)、促卵泡激素(FSH)、促黄体生成素(LH)、睾酮(T)]及炎性因子[肿瘤坏死因子(TNF)-α、白细胞介素6(IL-6)、内皮抑素(ES)]水平,分析PCOS患者多普勒超声血流参数与其血清炎性因子、性激素水平的相关性。结果两组超声参数比较,病例组子宫RI、PI显著高于对照组(0.89±0.14 vs 0.81±0.12、2.87±0.26 vs2.14±0.21。P<0.05),卵巢RI、PI显著低于对照组(0.43±0.07 vs 0.62±0.12、0.73±0.11 vs 0.91±0.14。P<0.05)。病例组血清LH、T水平显著高于对照组[(9.33±1.64)U/L vs(4.59±1.02)U/L、(1.14±0.13)ng/mL vs(0.61±0.08)ng/mL。P<0.05],FSH水平显著低于对照组[(6.31±1.02)U/L vs(8.96±1.28)U/L。P<0.05],E2水平差异无统计学意义(P>0.05)。病例组血清TNF-α、IL-6、ES均显著高于对照组[(20.95±3.05)ng/mL vs(12.52±2.51)ng/mL、(12.54±1.57)ng/mL vs(6.33±1.05)pg/mL、(234.25±16.33)μg/L vs(156.97±17.05)μg/L。P<0.05]。PCOS患者子宫RI、PI与患者LH、T水平正相关(r=0.531、0.433、0.371、0.407,均P<0.05),与FSH水平负相关(r=-0.963、-1.081,P<0.05);卵巢RI、PI与患者血清LH、T水平负相关(r=-2.082、-1.214、-1.530、-1.094,均P<0.05),与FSH水平正相关(r=0.392、0.583,均P<0.05);PCOS患者子宫RI、PI与血清TNF-α、IL-6、ES均为正相关(r=0.364、0.561、0.385、0.269、0.312、0.405,均P<0.05),卵巢RI、PI与血清TNF-α、IL-6、ES均为负相关(r=-2.634、-3.397、-1.482、-0.398、-1.433、-2.317,均P<0.05)。结论PCOS患者普遍存在子宫及卵巢血流动力学异常,并伴有炎性因子及部分性激素水平高表达,其子宫、卵巢多普勒超声参数与性激素、炎性因子水平具有相关性。
