目的 探讨急性心肌梗死患者血清同型半胱氨酸水平变化情况，分析其与心力衰竭发生的关系。方法 选取2012年10月～2013年10月期间在石家庄市第一医院CCU病房住院的急性心肌梗死患者100例，其中男性84例，女性16例，年龄49～84（63.6±...目的 探讨急性心肌梗死患者血清同型半胱氨酸水平变化情况，分析其与心力衰竭发生的关系。方法 选取2012年10月～2013年10月期间在石家庄市第一医院CCU病房住院的急性心肌梗死患者100例，其中男性84例，女性16例，年龄49～84（63.6±3.4）岁。将患者分为两组：高同型半胱氨酸组（Hcy＞10.8 μmol/L，H组，n=49）；对照组（Hcy＜10.8 μmol/L，C组，n=51）。检测患者入院时Hcy、脑钠肽（BNP）、左室射血分数（LVEF）水平，以及肌酸激酶（CK）、肌钙蛋白T（TnT）峰值等。记录入院后心力衰竭发生情况。结果 H组的HCY水平明显高于C组[（17.4±1.4）μmol/L vs. （8.2±0.3）μmol/L]，差异有统计学意义（P＜0.01）。采用Kaplan-Meier曲线对两组患者的心力衰竭发病率进行比较，H组的发病率明显高于C组（43.7% vs. 12.5%，P＜0.001）。入院时心功能分级为KillipⅠ级（没有心力衰竭的相关症状）的患者81例，H1组38例，C1组43例。结果显示，H1组患者的血清同型半胱氨酸水平显著高于C1组 [（17.4±1.6）μmol/L vs. （8.2±0.3）μmol/L]，充血性心力衰竭发病率也显著高于C1组（28.9% vs. 7.0%），差异有统计学意义（P均＜0.05）。多因素Cox回归分析表明高于10.8 μmol/L的血清HCY（HR=7.175，95%CI：1.152~44.707）是发生心力衰竭的独立预测因子。结论 部分急性心肌梗死患者血清半胱氨酸水平升高，而较高的血清同型半胱氨酸水平是发生心力衰竭的危险因素。展开更多
In order to study the rules of rock bursts caused by faults by means of mechanical analysis of a roof rock-mass balanced structure and numerical simulation about fault slip destabilization, the effect of coal mining o...In order to study the rules of rock bursts caused by faults by means of mechanical analysis of a roof rock-mass balanced structure and numerical simulation about fault slip destabilization, the effect of coal mining operation on fault plane stresses and slip displacement were studied. The results indicate that the slip displacement sharply increases due to the decrease of normal stress and the increase of shear stress at the fault plane when the working face advances from the footwall to the fault itself, which may induce a fault rock burst. However, this slip displacement will be very small due to the increase of normal stress and the decrease of shear stress when the working face advances from the hanging wall to the fault itself, which results in a very small risk of a fault rock burst.展开更多
For the purpose of having a better understanding of failure mechanisms of rock fracturing in mines, the equivalent point source models of tensile, shear and explosive seismic events were established, and the relations...For the purpose of having a better understanding of failure mechanisms of rock fracturing in mines, the equivalent point source models of tensile, shear and explosive seismic events were established, and the relationship between far-field seismic displacements of the waves and the corresponding equivalent forces were analyzed as well. Based on the results of a microseismic monitoring carried out in the mining progress of 9202 working face under the upper remnant coal pillar in Sanhejian Mine, the waveform features of the seismic events associated with different failure modes were further analyzed. The results show that the signals corresponding to different failure mechanisms have different radiation patterns of the seismic displacements, and different characteristics in waveform features, such as dominant frequency, energy released, the ratio of S- to P-wave energy, and so on. In addition, the rock burst happened in the high stress zone is mainly the result of the strong shear fracturing in the mining process. The results of this study have significantly improved the understanding of the characteristics of the failures associated with underground mining, and will greatly benefit the prevention and control of rock burst hazards in burst-prone mines.展开更多
文摘目的 探讨急性心肌梗死患者血清同型半胱氨酸水平变化情况，分析其与心力衰竭发生的关系。方法 选取2012年10月～2013年10月期间在石家庄市第一医院CCU病房住院的急性心肌梗死患者100例，其中男性84例，女性16例，年龄49～84（63.6±3.4）岁。将患者分为两组：高同型半胱氨酸组（Hcy＞10.8 μmol/L，H组，n=49）；对照组（Hcy＜10.8 μmol/L，C组，n=51）。检测患者入院时Hcy、脑钠肽（BNP）、左室射血分数（LVEF）水平，以及肌酸激酶（CK）、肌钙蛋白T（TnT）峰值等。记录入院后心力衰竭发生情况。结果 H组的HCY水平明显高于C组[（17.4±1.4）μmol/L vs. （8.2±0.3）μmol/L]，差异有统计学意义（P＜0.01）。采用Kaplan-Meier曲线对两组患者的心力衰竭发病率进行比较，H组的发病率明显高于C组（43.7% vs. 12.5%，P＜0.001）。入院时心功能分级为KillipⅠ级（没有心力衰竭的相关症状）的患者81例，H1组38例，C1组43例。结果显示，H1组患者的血清同型半胱氨酸水平显著高于C1组 [（17.4±1.6）μmol/L vs. （8.2±0.3）μmol/L]，充血性心力衰竭发病率也显著高于C1组（28.9% vs. 7.0%），差异有统计学意义（P均＜0.05）。多因素Cox回归分析表明高于10.8 μmol/L的血清HCY（HR=7.175，95%CI：1.152~44.707）是发生心力衰竭的独立预测因子。结论 部分急性心肌梗死患者血清半胱氨酸水平升高，而较高的血清同型半胱氨酸水平是发生心力衰竭的危险因素。
基金Projects 50490273 and 50474068 supported by the National Natural Science Foundation of China2006BAK04B02 and 2006BAK03B06 by the Support Programs of the National Science and Technique During the 11th Five-Year Period2005CB221504 by the State Basic Research Program of China
文摘In order to study the rules of rock bursts caused by faults by means of mechanical analysis of a roof rock-mass balanced structure and numerical simulation about fault slip destabilization, the effect of coal mining operation on fault plane stresses and slip displacement were studied. The results indicate that the slip displacement sharply increases due to the decrease of normal stress and the increase of shear stress at the fault plane when the working face advances from the footwall to the fault itself, which may induce a fault rock burst. However, this slip displacement will be very small due to the increase of normal stress and the decrease of shear stress when the working face advances from the hanging wall to the fault itself, which results in a very small risk of a fault rock burst.
基金Projects 50474068 supported by the National Natural Science Foundation of China2005CB221504 by the National Basic Research Program of China+2 种基金2006BAK04B02 and 2006BAK04B06 by the National Eleventh Five-Year Key Science & Technology Project[2007]3020 by the State Scholarship Fund of China Scholarship Councilprovided by the National Basic Research Program of China (2005CB221501)
文摘For the purpose of having a better understanding of failure mechanisms of rock fracturing in mines, the equivalent point source models of tensile, shear and explosive seismic events were established, and the relationship between far-field seismic displacements of the waves and the corresponding equivalent forces were analyzed as well. Based on the results of a microseismic monitoring carried out in the mining progress of 9202 working face under the upper remnant coal pillar in Sanhejian Mine, the waveform features of the seismic events associated with different failure modes were further analyzed. The results show that the signals corresponding to different failure mechanisms have different radiation patterns of the seismic displacements, and different characteristics in waveform features, such as dominant frequency, energy released, the ratio of S- to P-wave energy, and so on. In addition, the rock burst happened in the high stress zone is mainly the result of the strong shear fracturing in the mining process. The results of this study have significantly improved the understanding of the characteristics of the failures associated with underground mining, and will greatly benefit the prevention and control of rock burst hazards in burst-prone mines.
