目的探讨病毒性心肌炎(viralmyocarditis,VMC)患儿动态心电图检查中时域、频域指标的变化及其与心肌酶学指标的关系。方法受试者均来自河北省儿童医院2016年1月一2018年5月期间就诊的儿童,随机选取符合条件的VMC患儿200例设为VMC组,选...目的探讨病毒性心肌炎(viralmyocarditis,VMC)患儿动态心电图检查中时域、频域指标的变化及其与心肌酶学指标的关系。方法受试者均来自河北省儿童医院2016年1月一2018年5月期间就诊的儿童,随机选取符合条件的VMC患儿200例设为VMC组,选取来本院体检的健康儿童100例设为对照组。对比两组患儿动态心电图检查中的时域、频域指标、心肌酶学指标,并探讨其相关性。结果VMC组患儿的总体标准差(standard diviation of NN intervals,SDNN)、均值标准差(standard diviation of average NN intervals,SDANN)显著的低于对照组(P<0.05);VMC组的差值均方根(root mean square of the difference,rMMSD)、差值〉50msRR间期所占的百分比(percent of the number whose difference between adjacent NN interval are more than 50 ms,pNN50)值与对照组比较差异无统计学意义(P>0.05);VMC组患儿的低频功率(low frequency,LF)、高频功率(high frequency,HF)、LF/HF值均显著的低于对照组(P<0.05);VMC组患儿血清肌酸激酶同工酶(creatine kinase MB,CK-MB)、LDH、cTnI、α-HBDH检测水平均显著的高于对照组(P<0.05);VMC组患儿血清CK-MB、乳酸脱氢酶(lactic dehydrogenase,LDH)、心肌肌钙蛋白I(Cardiac troponin I,cTnl)、α-羟丁酸脱氢酶(α-Hydroxybutyrate Dehydrogenase,α-HBDH)检测值与患儿LF、HF、SDNN、SDANN测定值均呈显著的负相关关系(P<0.05)。结论VMC患儿的早期动态心电图的时域及频域指标与心肌酶学指标显著相关,可对患儿心肌损害程度进行早期评价。展开更多
Adsorption of potassium and sodium ions by four typical variable charge soils of South China was studied. The results indicated that the variable charge soils saturated with H and Al showed a much higher preference fo...Adsorption of potassium and sodium ions by four typical variable charge soils of South China was studied. The results indicated that the variable charge soils saturated with H and Al showed a much higher preference for potassium ions relative to sodium ions, and this tendency could not be changed by such factors as the pH, the concentration of the cations, the dielectric constant of solvent, the accompanying anions and the iron oxide content etc., suggesting that this difference in affinity is caused by the difference in the nature of the two cations. It was observed that a negative adsorption of sodium ions by latosol and lateritic red soil in a mixed system containing equal amount of potassium and sodium ions at low pH, which is caused by a competitive adsorption of potassium and sodium ions and repulsion of positive charge on the surfaces of soil particles for cations. The adsorption of potassium and sodium ions increased with the decreases in the dielectric constant of solvent and the iron oxide content. Sulfate affected the adsorption of potassium and sodium ions through changing the surface properties of the soils.展开更多
Interactions of potassium and calcium ions with four typical variable charge soils in South China were examined by measuring pK-0.5pCa value with a potassium ion-selective electrode and a calcium ion-selective electro...Interactions of potassium and calcium ions with four typical variable charge soils in South China were examined by measuring pK-0.5pCa value with a potassium ion-selective electrode and a calcium ion-selective electrode,and pK value with a potassium ion-selective electrode.The results showed that adsorption of potassium and calcium ions increased with soil suspension pH,and the tendency of the pK-0.5pCa value changing with pH differed with respect to pH range and potassium to calcium ratio.Adsorption of equal amount of calcium and potassium ions led to release of an identical number of protons,suggesting similar adsorption characteristics of these two ions when adsorbed by variable charge soils.Compared with red soil,latosol and lateritic red soil had higher adsorption selectivities for calcium ion.The red soil had a greater affinity for potassium ion than that for calcium ion at low concentration,which seems to result from its possession of 2:1 type minerals,such as vermiculite and mica with a high affinity for potassium ion.The results indicated that adsorption of potassium and calcium ions by the variable charge soils was chiefly caused by the electrostatic attraction between the cations and the soil surfaces.Moreover,it was found that sulfate could affect the adsorption by changing soil surface properties and by forming ion-pair.展开更多
A K+-selective electrode and a Na+-selective electrode were used to construct a measuring cell without liquid-junction for the determination of the ion activity ratio of K+ to Na+ in soil suspensions. The measured cel...A K+-selective electrode and a Na+-selective electrode were used to construct a measuring cell without liquid-junction for the determination of the ion activity ratio of K+ to Na+ in soil suspensions. The measured cell potential was not affected by the total electrolyte concentration when the total cation concentration was 10-1-10-3 mol L-1 and the concentration ratio CK+ / CNa+. was 10:1 to 1:50. When the concentration ratios were equal to 1and the total electrolyte concentrations were 10-2 and 10-3 mol L-1, the ion activity ratio measurement would not be affected by pH in the pH range of 3.5 to 11.5 and 4.4 to 11 respectively. Ions other than H+ have no remarkable influence on the measurement. The ion activity ratio of K+ to Na+ measured directly in soil suspension agree well with those in centrifuged supernant solution. The relative deviation was within 4%. From the measured ion activity ratio, the difference of the bonding energies of K+ and Na+ ions was calculated.展开更多
对贺兰山北寺自然保护区油松(Pinus tabulaeformis)的根际土壤固氮菌多样性和群落结构进行研究。采用阿须贝培养基对土壤中的固氮菌进行分离和纯化,用通用引物27f/1492r对固氮菌进行16S r DNA扩增并测序,应用DNAMAN 6.0软件进行多序列比...对贺兰山北寺自然保护区油松(Pinus tabulaeformis)的根际土壤固氮菌多样性和群落结构进行研究。采用阿须贝培养基对土壤中的固氮菌进行分离和纯化,用通用引物27f/1492r对固氮菌进行16S r DNA扩增并测序,应用DNAMAN 6.0软件进行多序列比对,用MEGA 4.0软件构建聚类树。结果表明:从贺兰山北寺油松根际土壤中分离出的固氮菌属于假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)、叶杆菌属(Phyllobacterium)、节杆菌属(Arthrobacter)、根瘤菌属(Rhizobium)、类芽孢杆菌属(Paenibacillus)、鞘氨醇单胞菌属(Sphingomonas)、柄细菌属(Caulobacter)、土地杆菌属(Pedobacter)等9个不同的类群,其中假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)、叶杆菌属(Phyllobacterium)、节杆菌属(Arthrobacter)是优势类群。这表明贺兰山北寺地区油松根际土壤中固氮菌具有较丰富的多样性。展开更多
文摘目的探讨病毒性心肌炎(viralmyocarditis,VMC)患儿动态心电图检查中时域、频域指标的变化及其与心肌酶学指标的关系。方法受试者均来自河北省儿童医院2016年1月一2018年5月期间就诊的儿童,随机选取符合条件的VMC患儿200例设为VMC组,选取来本院体检的健康儿童100例设为对照组。对比两组患儿动态心电图检查中的时域、频域指标、心肌酶学指标,并探讨其相关性。结果VMC组患儿的总体标准差(standard diviation of NN intervals,SDNN)、均值标准差(standard diviation of average NN intervals,SDANN)显著的低于对照组(P<0.05);VMC组的差值均方根(root mean square of the difference,rMMSD)、差值〉50msRR间期所占的百分比(percent of the number whose difference between adjacent NN interval are more than 50 ms,pNN50)值与对照组比较差异无统计学意义(P>0.05);VMC组患儿的低频功率(low frequency,LF)、高频功率(high frequency,HF)、LF/HF值均显著的低于对照组(P<0.05);VMC组患儿血清肌酸激酶同工酶(creatine kinase MB,CK-MB)、LDH、cTnI、α-HBDH检测水平均显著的高于对照组(P<0.05);VMC组患儿血清CK-MB、乳酸脱氢酶(lactic dehydrogenase,LDH)、心肌肌钙蛋白I(Cardiac troponin I,cTnl)、α-羟丁酸脱氢酶(α-Hydroxybutyrate Dehydrogenase,α-HBDH)检测值与患儿LF、HF、SDNN、SDANN测定值均呈显著的负相关关系(P<0.05)。结论VMC患儿的早期动态心电图的时域及频域指标与心肌酶学指标显著相关,可对患儿心肌损害程度进行早期评价。
文摘Adsorption of potassium and sodium ions by four typical variable charge soils of South China was studied. The results indicated that the variable charge soils saturated with H and Al showed a much higher preference for potassium ions relative to sodium ions, and this tendency could not be changed by such factors as the pH, the concentration of the cations, the dielectric constant of solvent, the accompanying anions and the iron oxide content etc., suggesting that this difference in affinity is caused by the difference in the nature of the two cations. It was observed that a negative adsorption of sodium ions by latosol and lateritic red soil in a mixed system containing equal amount of potassium and sodium ions at low pH, which is caused by a competitive adsorption of potassium and sodium ions and repulsion of positive charge on the surfaces of soil particles for cations. The adsorption of potassium and sodium ions increased with the decreases in the dielectric constant of solvent and the iron oxide content. Sulfate affected the adsorption of potassium and sodium ions through changing the surface properties of the soils.
文摘Interactions of potassium and calcium ions with four typical variable charge soils in South China were examined by measuring pK-0.5pCa value with a potassium ion-selective electrode and a calcium ion-selective electrode,and pK value with a potassium ion-selective electrode.The results showed that adsorption of potassium and calcium ions increased with soil suspension pH,and the tendency of the pK-0.5pCa value changing with pH differed with respect to pH range and potassium to calcium ratio.Adsorption of equal amount of calcium and potassium ions led to release of an identical number of protons,suggesting similar adsorption characteristics of these two ions when adsorbed by variable charge soils.Compared with red soil,latosol and lateritic red soil had higher adsorption selectivities for calcium ion.The red soil had a greater affinity for potassium ion than that for calcium ion at low concentration,which seems to result from its possession of 2:1 type minerals,such as vermiculite and mica with a high affinity for potassium ion.The results indicated that adsorption of potassium and calcium ions by the variable charge soils was chiefly caused by the electrostatic attraction between the cations and the soil surfaces.Moreover,it was found that sulfate could affect the adsorption by changing soil surface properties and by forming ion-pair.
文摘A K+-selective electrode and a Na+-selective electrode were used to construct a measuring cell without liquid-junction for the determination of the ion activity ratio of K+ to Na+ in soil suspensions. The measured cell potential was not affected by the total electrolyte concentration when the total cation concentration was 10-1-10-3 mol L-1 and the concentration ratio CK+ / CNa+. was 10:1 to 1:50. When the concentration ratios were equal to 1and the total electrolyte concentrations were 10-2 and 10-3 mol L-1, the ion activity ratio measurement would not be affected by pH in the pH range of 3.5 to 11.5 and 4.4 to 11 respectively. Ions other than H+ have no remarkable influence on the measurement. The ion activity ratio of K+ to Na+ measured directly in soil suspension agree well with those in centrifuged supernant solution. The relative deviation was within 4%. From the measured ion activity ratio, the difference of the bonding energies of K+ and Na+ ions was calculated.
