Objective The changes in serum adipokines and cytokines related to oxidative stress were examined during 3 months ‘Off to On’ and ‘On to Off’ periods using negatively charged particle-dominant indoor air condition...Objective The changes in serum adipokines and cytokines related to oxidative stress were examined during 3 months ‘Off to On’ and ‘On to Off’ periods using negatively charged particle-dominant indoor air conditions（NCPDIAC）.Methods Seven volunteers participated in the study,which included ‘OFF to 3 months ON’ periods（ON trials） for a total of 16 times,and ‘ON to 3 months OFF’（OFF trials） periods for a total of 13 times.Results With the exception of one case,serum amyloid A（SAA） levels decreased significantly during the ON trials.Conclusion Considering that SAA is an acute phase reactive protein such as C reactive protein（CRP）,this observed decrease might indicate the prevention of cardiovascular and atherosclerotic changes,since an increase in high-sensitive CRP is associated with the subsequent detection of these events.展开更多
The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were...The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were grown in severely Mo-deficient acidic soil （Tamm-reagent-extractable Mo 0.112 mg kg^-1） with （＋Mo） and without （-Mo） the application of 0.13 mg kg^-1 Mo. The accumulation and use efficiency of plant total N were significantly higher in ＋Mo than that in -Mo and in eft than that in ineff under Mo deficiency. N use efficiency was remarkably higher in maturity but it was forwarded to jointing stage after Mo supply, thus indicating that Mo supply promoted the N use efficiency besides N uptake and eff was efficient in N uptake and utilization. The overall activity of nitrate reductase （NR, EC 1.6.6.1） was significantly higher in ＋Mo than in -Mo and ratio of ＋Mo/-Mo was even to 14.8 at filleting stage for ineff. Activity of glutamine synthetase （GS, EC 6.3.1.2） was significantly lower in ＋Mo than in -Mo. Concentration of nitrate and glutamate were also significantly lower in ＋Mo than in -Mo, thus provided evidences for enhancing N use efficiency by Mo supply. Activities of NR and GS were significantly higher and concentrations of nitrate and glutamate were significantly lower in eff than ineff under Mo deficiency, thus indicated eff was more efficient in N reduction and utilization. It is therefore concluded that Mo could promote N accumulation and utilization in winter wheat which was directly related to NR and feedback regulated by GS. Higher Mo status also results in higher accumulation and utilization of plant N in eft.展开更多
The synthesis and luminescence properties of Zn2 SiO4: Mn phosphor layers on spherical silica spheres, i.e.,a kind of core-shell complex phosphor, Zn2SiO4: Mn@ SiO2 were described.Firstly, monodisperse silica spheres ...The synthesis and luminescence properties of Zn2 SiO4: Mn phosphor layers on spherical silica spheres, i.e.,a kind of core-shell complex phosphor, Zn2SiO4: Mn@ SiO2 were described.Firstly, monodisperse silica spheres were obtained via the Stober method by the hydrolysis of tetraethoxysilane(TEOS) Si ( OC2H5 ) 4 under base condition ( using NH4 OH as the catalyst).Secondly, the silica spheres were coated with a Zn2 SiO4: Mn phosphor layer by a Pechini solgel process.X-ray diffraction ( XRD), scanning electron microscope ( SEM), energy-dispersive X-ray spectrum ( EDS )and photoluminescence (PL) were employed to characterize the resulting complex phosphor.The results confirm that1000 ℃ annealed sample consists of crystalline Zn2SiO4: Mn shells and amorphous SiO2 cores.The phosphor show the green emission of Mn2+ at 521 nm corresponding 4T1 (4G) - 6 A1 (6S) transition, and the possible luminescence mechanism is proposed.展开更多
Flame heating combined with water cooling was used to straighten A6N01 aluminum alloy welded joint and effect of flame heating pass on its microstructure and mechanical properties was studied. Results showed that the ...Flame heating combined with water cooling was used to straighten A6N01 aluminum alloy welded joint and effect of flame heating pass on its microstructure and mechanical properties was studied. Results showed that the flame induced the precipitation and growth of the Mg_2Si phase on the Al substrate for the thermal aging A6N01 aluminum alloy welded joints,thus it led the decrease of micro-hardness and tensile strength of the A6N01 aluminum alloy welded joint with the increase of the heating pass. However,the fatigue property of the flame heated joint was improved because the Mg_2Si precipitation hindered the initiation and propagation of the fatigue crack.展开更多
目的:探讨肥胖相关指标与DNA甲基化时钟及其加速指标之间的关系,并分析两者在时间上的先后顺序。方法:研究数据来源于中国双生子登记系统在2013年和2017—2018年开展的两次专题调查。通过Illumina Infinium人类甲基化450K芯片和EPIC芯...目的:探讨肥胖相关指标与DNA甲基化时钟及其加速指标之间的关系,并分析两者在时间上的先后顺序。方法:研究数据来源于中国双生子登记系统在2013年和2017—2018年开展的两次专题调查。通过Illumina Infinium人类甲基化450K芯片和EPIC芯片测定外周血DNA甲基化数据,并采用DNA甲基化年龄计算器(https://dnamage.genetics.ucla.edu/)或研究者提供的R代码计算DNA甲基化时钟指标GrimAA、PCGrimAA和DunedinPACE。肥胖指标包括体重、体重指数(body mass index,BMI)、腰围、腰臀比、腰高比。横断面分析纳入1070名双生子,对内分析同卵双生子378对,异卵双生子155对,采用混合效应模型分析肥胖指标与DNA甲基化时钟及其加速指标的相关性。纵向分析纳入314名双生子,对内分析同卵双生子95对,异卵双生子62对,采用交叉滞后模型进一步探索肥胖与DNA甲基化时钟指标间的时间顺序关联。上述分析均分别在全部双生子和同卵、异卵双生子对内进行。结果:横断面分析人群中同卵双生子占71.0%,男性占68.0%,平均实足年龄为(49.9±12.1)岁;纵向分析人群中同卵双生子占60.5%,男性占60.8%;基线平均实足年龄为(50.4±10.2)岁,平均随访时间(4.6±0.6)年。除随访时腰臀比均值高于基线外,其他肥胖指标基线与随访均值差异无统计学意义。相关性分析显示,在全部双生子中,体重、BMI、腰围、腰臀比、腰高比均与DunedinPACE时钟呈正相关,其中腰高比与DunedinPACE时钟的关联最为显著(β=0.21,95%CI:0.11~0.31);体重和BMI均与GrimAA呈负相关(β=-0.03,95%CI:-0.05~-0.01;β=-0.07,95%CI:-0.12~-0.02),体重与PCGrimAA呈负相关(β=-0.02,95%CI:-0.03~0.00);但双生子对内分析中的相关性未达到统计学显著水平。交叉滞后分析显示,基线体重升高可能引起随访时GrimAA增加,基线体重、BMI和腰围升高可能引起随访时PCGrimAA增加,基线腰臀比升高可能引起随访时DunedinPACE升高。结论:肥胖指标与DNA甲基化时钟指标存在相关,基线肥胖指标对随访时部分DNA甲基化时钟指标的变化具有影响,肥胖可能通过加速DNA甲基化时钟和衰老进程对个体健康产生长期影响,但二者间的关联受双生子共享的遗传或环境因素影响。展开更多
【目的】旨在评估集成学习神经网络模型对落叶松木质材料本构关系的拟合能力和泛化能力,为优化木质产品加工成型提出一种高效率、高精度预测材料受力变形关系的新技术方法。【方法】以落叶松木材为研究对象,结合顺纹压缩试验的标准,前...【目的】旨在评估集成学习神经网络模型对落叶松木质材料本构关系的拟合能力和泛化能力,为优化木质产品加工成型提出一种高效率、高精度预测材料受力变形关系的新技术方法。【方法】以落叶松木材为研究对象,结合顺纹压缩试验的标准,前期对试件的表征和湿度进行了处理,对落叶松木质材料5组试件进行单轴压缩试验,将试验数据作为数据源,在对其进行去噪、聚类、归一等处理的基础上,对12600组数据进行特征提取,建立了学习知识库。利用改进的CLIQUE(Clustering in QUEst)算法对知识库中的样本进行聚类分析,结合局部优化原理和集成学习组合优化理论,构建出一种基于集成学习神经网络的落叶松木质材料受压本构关系模型;然后对关系模型进行训练、学习和仿真,使模型的参数得到优化确认。【结果】1)相比于理论模型,基于集成学习神经网络的落叶松木质材料受压本构关系模型能够与试验数据之间取得更好的吻合效果,说明该模型适合用来描述落叶松木材顺纹受压的力学行为;2)基于集成学习神经网络模型学习速度快,拟合精度高,泛化能力强,可作为材料非线性本构关系的研究模型;3)从试验曲线来看,落叶松材料的抗压强度和弹性模量的变化规律符合弹性力学应力状态分析结论,可以根据本研究提出的模型来预测顺纹方向压力作用下落叶松材料的非线性应力-应变关系;4)预测结果与试验测试存在一定的偏差,可能来自试件的离散性、试件的加工误差和模型学习样本偏少等方面原因。【结论】该模型具有很高的拟合精度和较强的预测能力,可为研究木材本构关系提供一种技术与方法上的参考,对落叶松木材加工成型也有一定的指导意义。展开更多
黑龙江省陆地生态系统固碳能力较强且易受气候变化影响,分析该区域陆地生态系统碳收支的时空格局及气候变化影响,对提升黑龙江省生态系统固碳功能具有重要意义。本研究基于1961—2022年气候数据和叶面积指数数据,采用生态系统碳循环BEP...黑龙江省陆地生态系统固碳能力较强且易受气候变化影响,分析该区域陆地生态系统碳收支的时空格局及气候变化影响,对提升黑龙江省生态系统固碳功能具有重要意义。本研究基于1961—2022年气候数据和叶面积指数数据,采用生态系统碳循环BEPS模型,定量模拟黑龙江省陆地生态系统净初级生产力(NPP)和净生态系统生产力(NEP),并进行气候影响评估。结果表明:BEPS模型能够模拟黑龙江省固碳能力。1961—2022年,研究区植被固碳能力增强,其中,NPP年均增加1.5 g C·m^(-2),2010年之后增强趋势更显著,年均增加7.5 g C·m^(-2),森林生态系统固碳能力最强,农田生态系统固碳能力增长最显著。在气候变暖的背景下,最低温度、降水量和风速显著影响黑龙江省固碳能力,其中,降水量是最主要的影响因子。研究期间,降水与黑龙江省固碳量的相关系数总体增加,且相对贡献率最高,为46.1%,降水对于植被NEP的相对贡献率为67.1%。展开更多
基金supported by a Kawasaki Medical School Research Grant(28B051)
文摘Objective The changes in serum adipokines and cytokines related to oxidative stress were examined during 3 months ‘Off to On’ and ‘On to Off’ periods using negatively charged particle-dominant indoor air conditions（NCPDIAC）.Methods Seven volunteers participated in the study,which included ‘OFF to 3 months ON’ periods（ON trials） for a total of 16 times,and ‘ON to 3 months OFF’（OFF trials） periods for a total of 13 times.Results With the exception of one case,serum amyloid A（SAA） levels decreased significantly during the ON trials.Conclusion Considering that SAA is an acute phase reactive protein such as C reactive protein（CRP）,this observed decrease might indicate the prevention of cardiovascular and atherosclerotic changes,since an increase in high-sensitive CRP is associated with the subsequent detection of these events.
基金Financial supports by the National Natural Science Foun-dation of China (30070431)the Key Technologies R&D Program of China during the 9th Five-Year Plan period(95-Agric-18-04)+1 种基金the Doctoral Fund of Ministry of Edu-cation of China (200805041061)the Earmarked Fund for Modern Agro-Industry Technology Research System, China
文摘The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were grown in severely Mo-deficient acidic soil （Tamm-reagent-extractable Mo 0.112 mg kg^-1） with （＋Mo） and without （-Mo） the application of 0.13 mg kg^-1 Mo. The accumulation and use efficiency of plant total N were significantly higher in ＋Mo than that in -Mo and in eft than that in ineff under Mo deficiency. N use efficiency was remarkably higher in maturity but it was forwarded to jointing stage after Mo supply, thus indicating that Mo supply promoted the N use efficiency besides N uptake and eff was efficient in N uptake and utilization. The overall activity of nitrate reductase （NR, EC 1.6.6.1） was significantly higher in ＋Mo than in -Mo and ratio of ＋Mo/-Mo was even to 14.8 at filleting stage for ineff. Activity of glutamine synthetase （GS, EC 6.3.1.2） was significantly lower in ＋Mo than in -Mo. Concentration of nitrate and glutamate were also significantly lower in ＋Mo than in -Mo, thus provided evidences for enhancing N use efficiency by Mo supply. Activities of NR and GS were significantly higher and concentrations of nitrate and glutamate were significantly lower in eff than ineff under Mo deficiency, thus indicated eff was more efficient in N reduction and utilization. It is therefore concluded that Mo could promote N accumulation and utilization in winter wheat which was directly related to NR and feedback regulated by GS. Higher Mo status also results in higher accumulation and utilization of plant N in eft.
文摘The synthesis and luminescence properties of Zn2 SiO4: Mn phosphor layers on spherical silica spheres, i.e.,a kind of core-shell complex phosphor, Zn2SiO4: Mn@ SiO2 were described.Firstly, monodisperse silica spheres were obtained via the Stober method by the hydrolysis of tetraethoxysilane(TEOS) Si ( OC2H5 ) 4 under base condition ( using NH4 OH as the catalyst).Secondly, the silica spheres were coated with a Zn2 SiO4: Mn phosphor layer by a Pechini solgel process.X-ray diffraction ( XRD), scanning electron microscope ( SEM), energy-dispersive X-ray spectrum ( EDS )and photoluminescence (PL) were employed to characterize the resulting complex phosphor.The results confirm that1000 ℃ annealed sample consists of crystalline Zn2SiO4: Mn shells and amorphous SiO2 cores.The phosphor show the green emission of Mn2+ at 521 nm corresponding 4T1 (4G) - 6 A1 (6S) transition, and the possible luminescence mechanism is proposed.
文摘Flame heating combined with water cooling was used to straighten A6N01 aluminum alloy welded joint and effect of flame heating pass on its microstructure and mechanical properties was studied. Results showed that the flame induced the precipitation and growth of the Mg_2Si phase on the Al substrate for the thermal aging A6N01 aluminum alloy welded joints,thus it led the decrease of micro-hardness and tensile strength of the A6N01 aluminum alloy welded joint with the increase of the heating pass. However,the fatigue property of the flame heated joint was improved because the Mg_2Si precipitation hindered the initiation and propagation of the fatigue crack.
文摘目的:探讨肥胖相关指标与DNA甲基化时钟及其加速指标之间的关系,并分析两者在时间上的先后顺序。方法:研究数据来源于中国双生子登记系统在2013年和2017—2018年开展的两次专题调查。通过Illumina Infinium人类甲基化450K芯片和EPIC芯片测定外周血DNA甲基化数据,并采用DNA甲基化年龄计算器(https://dnamage.genetics.ucla.edu/)或研究者提供的R代码计算DNA甲基化时钟指标GrimAA、PCGrimAA和DunedinPACE。肥胖指标包括体重、体重指数(body mass index,BMI)、腰围、腰臀比、腰高比。横断面分析纳入1070名双生子,对内分析同卵双生子378对,异卵双生子155对,采用混合效应模型分析肥胖指标与DNA甲基化时钟及其加速指标的相关性。纵向分析纳入314名双生子,对内分析同卵双生子95对,异卵双生子62对,采用交叉滞后模型进一步探索肥胖与DNA甲基化时钟指标间的时间顺序关联。上述分析均分别在全部双生子和同卵、异卵双生子对内进行。结果:横断面分析人群中同卵双生子占71.0%,男性占68.0%,平均实足年龄为(49.9±12.1)岁;纵向分析人群中同卵双生子占60.5%,男性占60.8%;基线平均实足年龄为(50.4±10.2)岁,平均随访时间(4.6±0.6)年。除随访时腰臀比均值高于基线外,其他肥胖指标基线与随访均值差异无统计学意义。相关性分析显示,在全部双生子中,体重、BMI、腰围、腰臀比、腰高比均与DunedinPACE时钟呈正相关,其中腰高比与DunedinPACE时钟的关联最为显著(β=0.21,95%CI:0.11~0.31);体重和BMI均与GrimAA呈负相关(β=-0.03,95%CI:-0.05~-0.01;β=-0.07,95%CI:-0.12~-0.02),体重与PCGrimAA呈负相关(β=-0.02,95%CI:-0.03~0.00);但双生子对内分析中的相关性未达到统计学显著水平。交叉滞后分析显示,基线体重升高可能引起随访时GrimAA增加,基线体重、BMI和腰围升高可能引起随访时PCGrimAA增加,基线腰臀比升高可能引起随访时DunedinPACE升高。结论:肥胖指标与DNA甲基化时钟指标存在相关,基线肥胖指标对随访时部分DNA甲基化时钟指标的变化具有影响,肥胖可能通过加速DNA甲基化时钟和衰老进程对个体健康产生长期影响,但二者间的关联受双生子共享的遗传或环境因素影响。
文摘【目的】旨在评估集成学习神经网络模型对落叶松木质材料本构关系的拟合能力和泛化能力,为优化木质产品加工成型提出一种高效率、高精度预测材料受力变形关系的新技术方法。【方法】以落叶松木材为研究对象,结合顺纹压缩试验的标准,前期对试件的表征和湿度进行了处理,对落叶松木质材料5组试件进行单轴压缩试验,将试验数据作为数据源,在对其进行去噪、聚类、归一等处理的基础上,对12600组数据进行特征提取,建立了学习知识库。利用改进的CLIQUE(Clustering in QUEst)算法对知识库中的样本进行聚类分析,结合局部优化原理和集成学习组合优化理论,构建出一种基于集成学习神经网络的落叶松木质材料受压本构关系模型;然后对关系模型进行训练、学习和仿真,使模型的参数得到优化确认。【结果】1)相比于理论模型,基于集成学习神经网络的落叶松木质材料受压本构关系模型能够与试验数据之间取得更好的吻合效果,说明该模型适合用来描述落叶松木材顺纹受压的力学行为;2)基于集成学习神经网络模型学习速度快,拟合精度高,泛化能力强,可作为材料非线性本构关系的研究模型;3)从试验曲线来看,落叶松材料的抗压强度和弹性模量的变化规律符合弹性力学应力状态分析结论,可以根据本研究提出的模型来预测顺纹方向压力作用下落叶松材料的非线性应力-应变关系;4)预测结果与试验测试存在一定的偏差,可能来自试件的离散性、试件的加工误差和模型学习样本偏少等方面原因。【结论】该模型具有很高的拟合精度和较强的预测能力,可为研究木材本构关系提供一种技术与方法上的参考,对落叶松木材加工成型也有一定的指导意义。
文摘黑龙江省陆地生态系统固碳能力较强且易受气候变化影响,分析该区域陆地生态系统碳收支的时空格局及气候变化影响,对提升黑龙江省生态系统固碳功能具有重要意义。本研究基于1961—2022年气候数据和叶面积指数数据,采用生态系统碳循环BEPS模型,定量模拟黑龙江省陆地生态系统净初级生产力(NPP)和净生态系统生产力(NEP),并进行气候影响评估。结果表明:BEPS模型能够模拟黑龙江省固碳能力。1961—2022年,研究区植被固碳能力增强,其中,NPP年均增加1.5 g C·m^(-2),2010年之后增强趋势更显著,年均增加7.5 g C·m^(-2),森林生态系统固碳能力最强,农田生态系统固碳能力增长最显著。在气候变暖的背景下,最低温度、降水量和风速显著影响黑龙江省固碳能力,其中,降水量是最主要的影响因子。研究期间,降水与黑龙江省固碳量的相关系数总体增加,且相对贡献率最高,为46.1%,降水对于植被NEP的相对贡献率为67.1%。
