目的探讨零平衡超滤对急性A型主动脉夹层手术患者的肺保护作用。方法连续选取2019年1—12月于首都医科大学附属北京安贞医院接受手术治疗的急性A型主动脉夹层患者60例进行前瞻性随机对照研究,采用随机数字表法将患者分为观察组和对照组,...目的探讨零平衡超滤对急性A型主动脉夹层手术患者的肺保护作用。方法连续选取2019年1—12月于首都医科大学附属北京安贞医院接受手术治疗的急性A型主动脉夹层患者60例进行前瞻性随机对照研究,采用随机数字表法将患者分为观察组和对照组,各30例。观察组患者术中予零平衡超滤,对照组患者术中予常规超滤,比较2组手术及围术期资料、肺保护作用及预后情况。结果观察组与对照组体外循环时间、主动脉阻断时间、停循环时间、普通超滤量及手术方式比较差异均无统计学意义(均P>0.05)。2组术前乳酸、动脉血氧分压、动脉血氧饱和度、氧合指数差异均无统计学意义(均P>0.05);观察组术中并行阶段(T_(1))、术后1 h(T_(3))动脉血氧分压、动脉血氧饱和度、氧合指数均高于对照组[T_(1)时点:(174±82)mmHg(1 mmHg=0.133 k Pa)比(130±73)mmHg、(98.5±2.4)%比(94.6±6.7)%、(289±137)mmHg比(216±122)mmHg;T_(3)时点:(156±70)mmHg比(86±17)mmHg、(98.2±1.3)%比(96.0±2.9)%、(249±119)mmHg比(143±32)mmHg],差异均有统计学意义(均P<0.05)。观察组术后出现急性肺损伤、急性呼吸窘迫比例均低于对照组,住院天数少于对照组,差异有统计学意义(均P<0.05)。结论急性A型主动脉夹层患者术中联合使用零平衡超滤在围术期肺保护方面效果显著。展开更多
In this article, following a brief introduction concerning experimental measurements of surface and interfacial tensions, methods for calculating surface tension and surface segregation for binary, ternary, and multic...In this article, following a brief introduction concerning experimental measurements of surface and interfacial tensions, methods for calculating surface tension and surface segregation for binary, ternary, and multicomponent high-temperature melts based on Bulter＇s original treatment [ 1] and on available physical properties and thermodynamic data, especially excess Gibbs free energies of bulk phase and surface phase versus temperature obtained from thermodynamic databases using the calculation of phase diagram （CALPHAD） approach, with special attention to the model parameter β, have been described. In addition, the geometric models can be extended to predict surface tensions of multicom- ponent systems from those of sub-binary systems. For illustration, some calculated examples, including Pb-free soldering systems and phase-diagram evaluation of binary alloys in nanoparticle systems are given. On the basis of surface tensions of high-temperature melts, interracial tensions between liquid alloy and molten slag as well as molten slag and molten matter can be calculated using the Girifalco-Good equation [2]. Modifications are suggested in the Nishizawa＇s model [3] for estimation of interracial tension in liquid metal （A）/ceramics （MX） systems so that the calculations can be carried out based on the sublattice model and thermodynamic data, without deliberately differentiating the phase of MX at high temperature. Finally, the derivation of an approximate expression for predicting interfacial tension between the high-temperature multicomponent melts, employing Becker＇s model [4] in conjunction with Bulter＇s equation and inteffacial tension data of the simple systems is described, and some examples concerning pyrometallurgical systems are given for better understanding.展开更多
Two surfaces correponding to LaCl_3 and α-solid solution(MgCl_2.LiCl) respectively: and one secondary crystallization curve with a minimum M at 63.8 wt-％ LaCl_3,2.0 wt-％ MgCl_2,34.2 wt-％ LiCl and 492℃ were fonud ...Two surfaces correponding to LaCl_3 and α-solid solution(MgCl_2.LiCl) respectively: and one secondary crystallization curve with a minimum M at 63.8 wt-％ LaCl_3,2.0 wt-％ MgCl_2,34.2 wt-％ LiCl and 492℃ were fonud by means of DTA.In combination with liquidus determination.an approach was also made to the alteration in LnCl_3-MgCl_2-LiCl svstem,where Lu denotes La.Ce.Pr or Nd.展开更多
By use of micro-DTA technique as well as ambient and high temperature X-ray analysis the phase diagram of NaCl-CaCl_2 has been checked.It is.a simple eutectic system with a solid solubility in the sodium chloride side...By use of micro-DTA technique as well as ambient and high temperature X-ray analysis the phase diagram of NaCl-CaCl_2 has been checked.It is.a simple eutectic system with a solid solubility in the sodium chloride side.The eutectic point is at 773K,49 mol% NaCl.The experimental results,especially those of the X-ray diffraction studies have showed that the incongruent compound 4NaCl-CaCl_2 does not exist in the NaCl-CaCl_2 system.展开更多
文摘目的探讨零平衡超滤对急性A型主动脉夹层手术患者的肺保护作用。方法连续选取2019年1—12月于首都医科大学附属北京安贞医院接受手术治疗的急性A型主动脉夹层患者60例进行前瞻性随机对照研究,采用随机数字表法将患者分为观察组和对照组,各30例。观察组患者术中予零平衡超滤,对照组患者术中予常规超滤,比较2组手术及围术期资料、肺保护作用及预后情况。结果观察组与对照组体外循环时间、主动脉阻断时间、停循环时间、普通超滤量及手术方式比较差异均无统计学意义(均P>0.05)。2组术前乳酸、动脉血氧分压、动脉血氧饱和度、氧合指数差异均无统计学意义(均P>0.05);观察组术中并行阶段(T_(1))、术后1 h(T_(3))动脉血氧分压、动脉血氧饱和度、氧合指数均高于对照组[T_(1)时点:(174±82)mmHg(1 mmHg=0.133 k Pa)比(130±73)mmHg、(98.5±2.4)%比(94.6±6.7)%、(289±137)mmHg比(216±122)mmHg;T_(3)时点:(156±70)mmHg比(86±17)mmHg、(98.2±1.3)%比(96.0±2.9)%、(249±119)mmHg比(143±32)mmHg],差异均有统计学意义(均P<0.05)。观察组术后出现急性肺损伤、急性呼吸窘迫比例均低于对照组,住院天数少于对照组,差异有统计学意义(均P<0.05)。结论急性A型主动脉夹层患者术中联合使用零平衡超滤在围术期肺保护方面效果显著。
基金This study was financially supported by the National Natural Science Foundation of China (Nos. 59934090, 50071009) and the National Doctorate Fund of State Education Ministry of China (No. 2000000802)
文摘In this article, following a brief introduction concerning experimental measurements of surface and interfacial tensions, methods for calculating surface tension and surface segregation for binary, ternary, and multicomponent high-temperature melts based on Bulter＇s original treatment [ 1] and on available physical properties and thermodynamic data, especially excess Gibbs free energies of bulk phase and surface phase versus temperature obtained from thermodynamic databases using the calculation of phase diagram （CALPHAD） approach, with special attention to the model parameter β, have been described. In addition, the geometric models can be extended to predict surface tensions of multicom- ponent systems from those of sub-binary systems. For illustration, some calculated examples, including Pb-free soldering systems and phase-diagram evaluation of binary alloys in nanoparticle systems are given. On the basis of surface tensions of high-temperature melts, interracial tensions between liquid alloy and molten slag as well as molten slag and molten matter can be calculated using the Girifalco-Good equation [2]. Modifications are suggested in the Nishizawa＇s model [3] for estimation of interracial tension in liquid metal （A）/ceramics （MX） systems so that the calculations can be carried out based on the sublattice model and thermodynamic data, without deliberately differentiating the phase of MX at high temperature. Finally, the derivation of an approximate expression for predicting interfacial tension between the high-temperature multicomponent melts, employing Becker＇s model [4] in conjunction with Bulter＇s equation and inteffacial tension data of the simple systems is described, and some examples concerning pyrometallurgical systems are given for better understanding.
文摘Two surfaces correponding to LaCl_3 and α-solid solution(MgCl_2.LiCl) respectively: and one secondary crystallization curve with a minimum M at 63.8 wt-％ LaCl_3,2.0 wt-％ MgCl_2,34.2 wt-％ LiCl and 492℃ were fonud by means of DTA.In combination with liquidus determination.an approach was also made to the alteration in LnCl_3-MgCl_2-LiCl svstem,where Lu denotes La.Ce.Pr or Nd.
基金Projects Supported by the National Natural Science Fundation of China.
文摘By use of micro-DTA technique as well as ambient and high temperature X-ray analysis the phase diagram of NaCl-CaCl_2 has been checked.It is.a simple eutectic system with a solid solubility in the sodium chloride side.The eutectic point is at 773K,49 mol% NaCl.The experimental results,especially those of the X-ray diffraction studies have showed that the incongruent compound 4NaCl-CaCl_2 does not exist in the NaCl-CaCl_2 system.
