采用溶钙圈法从传统发酵肉制品中分离乳酸菌菌株,通过清除胆固醇、甘油三酯能力及胆盐水解酶活性测定筛选潜在改善高脂血症乳酸菌菌株。基于此,结合体外益生特性研究,利用主成分分析(PCA)筛选综合益生活性较好的菌株,并通过形态观察、...采用溶钙圈法从传统发酵肉制品中分离乳酸菌菌株,通过清除胆固醇、甘油三酯能力及胆盐水解酶活性测定筛选潜在改善高脂血症乳酸菌菌株。基于此,结合体外益生特性研究,利用主成分分析(PCA)筛选综合益生活性较好的菌株,并通过形态观察、生理生化试验及分子生物学技术对其进行菌种鉴定,最后评价该菌株对HepG2细胞高脂模型中胆固醇和甘油三酯含量的影响。结果表明,从传统发酵肉制品中共分离得到125株乳酸菌,最终筛选得到1株具有潜在改善高脂血症能力且综合益生活性最好的菌株LC4,被鉴定为戊糖片球菌(Pediococcus pentosus),其体外胆固醇及甘油三酯清除率分别为74.73%和91.65%,具有胆盐水解酶活性;模拟胃液及肠液的耐受力分别为87.57%和72.70%,在0.3%胆盐条件下处理24 h活菌数为9.79 lg CFU/mL,在pH 2.5酸条件下处理4 h,活菌数为7.67 lg CFU/mL;24 h后的自聚集能力为52.77%;对二甲苯、乙酸乙酯及氯仿的疏水性分别为78.13%、34.07%和10.30%。HepG2细胞高脂模型经菌株LC4处理后,降低了胆固醇和甘油三酯含量。展开更多
目的观察益智开窍针刺法联合益智汤治疗血管性痴呆的临床疗效。方法将104例血管性痴呆患者随机分为对照组和观察组,每组52例。对照组予口服益智汤治疗,观察组在对照组基础上另予益智开窍针刺法治疗。比较两组的临床疗效,观察两组治疗前...目的观察益智开窍针刺法联合益智汤治疗血管性痴呆的临床疗效。方法将104例血管性痴呆患者随机分为对照组和观察组,每组52例。对照组予口服益智汤治疗,观察组在对照组基础上另予益智开窍针刺法治疗。比较两组的临床疗效,观察两组治疗前后中医证候积分、简易精神状态检查表(mini-mental state examination,MMSE)评分、蒙特利尔认知评估(Montreal cognitive assessment,MoCA)评分、临床痴呆评定表(clinical dementia rating,CDR)评分及日常生活能力量表(activities of daily living scale,ADL)评分的变化,观察两组治疗前后血清神经营养因子[中枢神经特异性蛋白β(central nervous system specific proteinβ,S-100β)、神经元特异性烯醇化酶(neuron-specific enolase,NSE)和神经生长因子(nerve growth factor,NGF)]的水平变化,观察治疗前后两组患者大脑中动脉收缩期峰流速、平均血流速度和搏动指数的变化。结果观察组总有效率为94.2%,高于对照组的82.7%(P<0.05)。治疗后,两组中医证候积分、MMSE评分、CDR评分、S-100β水平、NSE水平、大脑中动脉收缩期峰流速和平均血流速度均较同组治疗前降低(P<0.05),两组NGF水平、MoCA评分、ADL评分、大脑中动脉搏动指数均较同组治疗前升高(P<0.05)。观察组治疗后上述指标均优于对照组(P<0.05)。结论益智开窍针刺法联合益智汤治疗血管性痴呆的临床疗效优于单一益智汤治疗,可改善临床症状,提高日常生活能力,改善大脑血流动力学和血清神经营养因子水平。展开更多
The reentry of uncontrolled spacecraft may be broken into many pieces of debris at an altitude in the range of 75-85 km. The surviving fragments could pose great hazard and risk to ground and people. In recent years, ...The reentry of uncontrolled spacecraft may be broken into many pieces of debris at an altitude in the range of 75-85 km. The surviving fragments could pose great hazard and risk to ground and people. In recent years, methods and tools for predicting and analyzing debris reentry and ground risk assessment have been studied and developed in National Aeronautics and Space Ad-ministration （NASA）, European Space Agency （ESA） and other organizations, including the group of the present authors. This paper reviews the current progress on this topic of debris reentry briefly. We outline the Monte Carlo method for uncertainty analysis, breakup prediction, and parameters affecting survivability of debris. The existing analysis tools can be classified into two categories, i.e. the object-oriented and the spacecraft-oriented methods, the latter being more accurate than the first one. The past object-oriented tools include objects of only simple shapes. For more realistic simulation, here we present an object-oriented tool debris reentry and ablation prediction system （DRAPS） developed by the present authors, which introduces new object shapes to 15 types, as well as 51 predefined motions and relevant aerodynamic and aerothermal models. The aerodynamic and aerothermal models in DRAPS are validated using direct simulation Monte Carlo （DSMC） method.展开更多
In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow bas...In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow based on computational or experimental results. Field plots by contours, iso-surfaces, streamlines, vectors and others are traditional post-processing techniques. While the shock wave, as one important and critical flow structure in many aerodynamic problems, can hardly be detected or distinguished in a direct way using these traditional methods, due to possible confusions with other similar discontinuous flow structures like slip line, contact discontinuity, etc. Therefore, method for automatic detection of shock wave in post-processing is of great importance for both academic research and engineering applications. In this paper, the current status of methodologies developed for shock wave detection and implementations in post-processing platform are reviewed, as well as discussions on advantages and limitations of the existing methods and proposals for further studies of shock wave detection method. We also develop an advanced post-processing software, with improved shock detection.展开更多
The conservation equations for heat conduction are established based on the concept of thermal mass.We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass.The...The conservation equations for heat conduction are established based on the concept of thermal mass.We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass.The general law introduces a damped thermal wave equation.It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected,which indicates that the CV model only considers the temporal inertia of heat flux.Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory.For larger thermal perturbation,however,the physically impossible phenomenon pre-dicted by CV model,i.e.the negative temperature induced by the thermal wave superposition,is eliminated by the general heat conduction law,which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.展开更多
In this study, palladium nanoparticles loaded graphdiyne oxide (Pd/GDYO) nanocomposite were fabricated by in-situ reduction of palladium chloride in the dispersion of GDYO, and characte-rized by Raman spectra, transmi...In this study, palladium nanoparticles loaded graphdiyne oxide (Pd/GDYO) nanocomposite were fabricated by in-situ reduction of palladium chloride in the dispersion of GDYO, and characte-rized by Raman spectra, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The synthesized Pd/GDYO was first found to have catalytic activities similar to those of the peroxidase enzyme, which can catalyze the oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine(TMB) in the presence of hydrogen peroxide(H2O2). Steady-state kinetic studies showed that the catalytic reaction of Pd/GDYO follows a ping-pong mechanism, and Pd/GDYO has a stronger activity to TMB with a Michaelis constant(Km) value of 5.32×10-4 mmol/L. Based on the shielding effect of glutathione(GSH) on the Pd/GDYO-H2O2-TMB reaction system, a colorimetric detection method for GSH was deve-loped with a wide linear range from 0.1 μmol/L to 40 μmol/L and a limit of detection of 0.1 μmol/L. The method was successfully applied for fast and accurate detection of GSH in injection powder drugs. It was expected that this peroxidase-like Pd/GDYO nano- composite would have wide applications in the fields of biomedicine and environmental chemistry.展开更多
A model based on a thermodynamic approach is proposed for predicting the dynamics of communicable epidemics assumed to be governed by controlling eforts of multiple scales so that an entropy is associated with the sys...A model based on a thermodynamic approach is proposed for predicting the dynamics of communicable epidemics assumed to be governed by controlling eforts of multiple scales so that an entropy is associated with the system.All the epidemic details are factored into a single and time-dependent coefcient,the functional form of this coefcient is found through four constraints,including notably the existence of an inflexion point and a maximum.The model is solved to give a log-normal distribution for the spread rate,for which a Shannon entropy can be defined.The only parameter,that characterizes the width of the distribution function,is uniquely determined through maximizing the rate of entropy production.This entropy-based thermodynamic(EBT)model predicts the number of hospitalized cases with a reasonable accuracy for SARS in the year 2003.This EBT model can be of use for potential epidemics such as avian influenza and H7N9 in China.展开更多
文摘采用溶钙圈法从传统发酵肉制品中分离乳酸菌菌株,通过清除胆固醇、甘油三酯能力及胆盐水解酶活性测定筛选潜在改善高脂血症乳酸菌菌株。基于此,结合体外益生特性研究,利用主成分分析(PCA)筛选综合益生活性较好的菌株,并通过形态观察、生理生化试验及分子生物学技术对其进行菌种鉴定,最后评价该菌株对HepG2细胞高脂模型中胆固醇和甘油三酯含量的影响。结果表明,从传统发酵肉制品中共分离得到125株乳酸菌,最终筛选得到1株具有潜在改善高脂血症能力且综合益生活性最好的菌株LC4,被鉴定为戊糖片球菌(Pediococcus pentosus),其体外胆固醇及甘油三酯清除率分别为74.73%和91.65%,具有胆盐水解酶活性;模拟胃液及肠液的耐受力分别为87.57%和72.70%,在0.3%胆盐条件下处理24 h活菌数为9.79 lg CFU/mL,在pH 2.5酸条件下处理4 h,活菌数为7.67 lg CFU/mL;24 h后的自聚集能力为52.77%;对二甲苯、乙酸乙酯及氯仿的疏水性分别为78.13%、34.07%和10.30%。HepG2细胞高脂模型经菌株LC4处理后,降低了胆固醇和甘油三酯含量。
文摘目的观察益智开窍针刺法联合益智汤治疗血管性痴呆的临床疗效。方法将104例血管性痴呆患者随机分为对照组和观察组,每组52例。对照组予口服益智汤治疗,观察组在对照组基础上另予益智开窍针刺法治疗。比较两组的临床疗效,观察两组治疗前后中医证候积分、简易精神状态检查表(mini-mental state examination,MMSE)评分、蒙特利尔认知评估(Montreal cognitive assessment,MoCA)评分、临床痴呆评定表(clinical dementia rating,CDR)评分及日常生活能力量表(activities of daily living scale,ADL)评分的变化,观察两组治疗前后血清神经营养因子[中枢神经特异性蛋白β(central nervous system specific proteinβ,S-100β)、神经元特异性烯醇化酶(neuron-specific enolase,NSE)和神经生长因子(nerve growth factor,NGF)]的水平变化,观察治疗前后两组患者大脑中动脉收缩期峰流速、平均血流速度和搏动指数的变化。结果观察组总有效率为94.2%,高于对照组的82.7%(P<0.05)。治疗后,两组中医证候积分、MMSE评分、CDR评分、S-100β水平、NSE水平、大脑中动脉收缩期峰流速和平均血流速度均较同组治疗前降低(P<0.05),两组NGF水平、MoCA评分、ADL评分、大脑中动脉搏动指数均较同组治疗前升高(P<0.05)。观察组治疗后上述指标均优于对照组(P<0.05)。结论益智开窍针刺法联合益智汤治疗血管性痴呆的临床疗效优于单一益智汤治疗,可改善临床症状,提高日常生活能力,改善大脑血流动力学和血清神经营养因子水平。
基金Space Debris Special Projects of State Administration of Science Technology and Industry for National Defense (KJSP- 2006303, KJSP-2009302)
文摘The reentry of uncontrolled spacecraft may be broken into many pieces of debris at an altitude in the range of 75-85 km. The surviving fragments could pose great hazard and risk to ground and people. In recent years, methods and tools for predicting and analyzing debris reentry and ground risk assessment have been studied and developed in National Aeronautics and Space Ad-ministration （NASA）, European Space Agency （ESA） and other organizations, including the group of the present authors. This paper reviews the current progress on this topic of debris reentry briefly. We outline the Monte Carlo method for uncertainty analysis, breakup prediction, and parameters affecting survivability of debris. The existing analysis tools can be classified into two categories, i.e. the object-oriented and the spacecraft-oriented methods, the latter being more accurate than the first one. The past object-oriented tools include objects of only simple shapes. For more realistic simulation, here we present an object-oriented tool debris reentry and ablation prediction system （DRAPS） developed by the present authors, which introduces new object shapes to 15 types, as well as 51 predefined motions and relevant aerodynamic and aerothermal models. The aerodynamic and aerothermal models in DRAPS are validated using direct simulation Monte Carlo （DSMC） method.
文摘In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow based on computational or experimental results. Field plots by contours, iso-surfaces, streamlines, vectors and others are traditional post-processing techniques. While the shock wave, as one important and critical flow structure in many aerodynamic problems, can hardly be detected or distinguished in a direct way using these traditional methods, due to possible confusions with other similar discontinuous flow structures like slip line, contact discontinuity, etc. Therefore, method for automatic detection of shock wave in post-processing is of great importance for both academic research and engineering applications. In this paper, the current status of methodologies developed for shock wave detection and implementations in post-processing platform are reviewed, as well as discussions on advantages and limitations of the existing methods and proposals for further studies of shock wave detection method. We also develop an advanced post-processing software, with improved shock detection.
基金Supported by the National Natural Science Foundation of China(Grant No.50606018)
文摘The conservation equations for heat conduction are established based on the concept of thermal mass.We obtain a general heat conduction law which takes into account the spatial and temporal inertia of thermal mass.The general law introduces a damped thermal wave equation.It reduces to the well-known CV model when the spatial inertia of heat flux and temperature and the temporal inertia of temperature are neglected,which indicates that the CV model only considers the temporal inertia of heat flux.Numerical simulations on the propagation and superposition of thermal waves show that for small thermal perturbation the CV model agrees with the thermal wave equation based on the thermal mass theory.For larger thermal perturbation,however,the physically impossible phenomenon pre-dicted by CV model,i.e.the negative temperature induced by the thermal wave superposition,is eliminated by the general heat conduction law,which demonstrates that the present heat conduction law based on the thermal mass theory is more reasonable.
基金supported by the National Natural Science Foundation of China(No.81573834)。
文摘In this study, palladium nanoparticles loaded graphdiyne oxide (Pd/GDYO) nanocomposite were fabricated by in-situ reduction of palladium chloride in the dispersion of GDYO, and characte-rized by Raman spectra, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The synthesized Pd/GDYO was first found to have catalytic activities similar to those of the peroxidase enzyme, which can catalyze the oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine(TMB) in the presence of hydrogen peroxide(H2O2). Steady-state kinetic studies showed that the catalytic reaction of Pd/GDYO follows a ping-pong mechanism, and Pd/GDYO has a stronger activity to TMB with a Michaelis constant(Km) value of 5.32×10-4 mmol/L. Based on the shielding effect of glutathione(GSH) on the Pd/GDYO-H2O2-TMB reaction system, a colorimetric detection method for GSH was deve-loped with a wide linear range from 0.1 μmol/L to 40 μmol/L and a limit of detection of 0.1 μmol/L. The method was successfully applied for fast and accurate detection of GSH in injection powder drugs. It was expected that this peroxidase-like Pd/GDYO nano- composite would have wide applications in the fields of biomedicine and environmental chemistry.
文摘A model based on a thermodynamic approach is proposed for predicting the dynamics of communicable epidemics assumed to be governed by controlling eforts of multiple scales so that an entropy is associated with the system.All the epidemic details are factored into a single and time-dependent coefcient,the functional form of this coefcient is found through four constraints,including notably the existence of an inflexion point and a maximum.The model is solved to give a log-normal distribution for the spread rate,for which a Shannon entropy can be defined.The only parameter,that characterizes the width of the distribution function,is uniquely determined through maximizing the rate of entropy production.This entropy-based thermodynamic(EBT)model predicts the number of hospitalized cases with a reasonable accuracy for SARS in the year 2003.This EBT model can be of use for potential epidemics such as avian influenza and H7N9 in China.
