Slow coronary flow phenomenon(SCFP) is an angiographic observation characterized by delayed distal vessel opacifi-cation in the absence of significant epicardial coronary disease. Only limited studies have been focuse...Slow coronary flow phenomenon(SCFP) is an angiographic observation characterized by delayed distal vessel opacifi-cation in the absence of significant epicardial coronary disease. Only limited studies have been focused on the etiologies,clinical manifestations and treatment of this unique angiographic phenomenon. In our case report,we described an 85-year-old man who came with significant ST segment elevation in leads V1-V4 and V3R-V5R without increase in myocardial enzyme. The patient also developed respiratory failure requiring intubation and mechanical ventilation. Coronary angiography revealed only mild atherosclerosis without spasm or thromboembolic occlusion. Slow flow was seen in all coronary arteries,especially in the left anterior descending and right coronary arteries. This case speculated that transmural myocardial ischemia with ST segment elevation might be resulted from slow coronary flow. Transmural myocardial ischemia can occur owing to abnormalities of the coronary microcirculation.展开更多
Urban water supply network is a modern urban survival and development of the infrastructure of a city,and its normal running conditions have important significance. The actual hydraulic process in the variableload wat...Urban water supply network is a modern urban survival and development of the infrastructure of a city,and its normal running conditions have important significance. The actual hydraulic process in the variableload water distribution networks can be treated as the slow transient flow which belongs to the unsteady flow. This paper analyzes the multi-loops network slow transient model based on graph theory,and the link flow matrix is treated as the variables of the discrete solution model to simulate the process of the slow transient flow in the network. With the simulation of hydraulic regime in an actual pipe network,the changing laws of the flow in the pipes,nodal hydraulic heads and other hydraulic factors with the passage of time are obtained. Since the transient processes offer much more information than a steady process,the slow transient theory is not only practical on analyzing the hydraulic condition of the network,but also on identifying hydraulic resistance coefficients of pipes and detecting the leakage in networks.展开更多
Objective:To explore the effect of nicorandil on the coronary artery microcirculation and hemodynamics in patients with coronary slow flow (CSF).Methods: A total of 86 patients with CSF who were admitted in our hospit...Objective:To explore the effect of nicorandil on the coronary artery microcirculation and hemodynamics in patients with coronary slow flow (CSF).Methods: A total of 86 patients with CSF who were admitted in our hospital were included in the study and randomized into the treatment group and the control group with 43 cases in each group. The patients in the control group were given aspirin, HMG-CoA reductase inhibitor, and ACEI. On this basis, the patients in the treatment group were given nicorandil. The patients in the two groups were continuously treated for 6 months. The coronary artery microcirculation and hemodynamic indicators before and after treatment in the two groups were detected and compared.Results:TAT, ET-1, and hs-CRP levels, LAD, LCX, RCA, TIMI average blood flow frame count value, and IMR after treatment in the two groups were significantly reduced when compared with before treatment (P<0.05). The above indicators after treatment in the treatment group were significantly lower than those in the control group (P<0.05). FMD after treatment in the two groups was significantly elevated when compared with before treatment (P<0.05). FMD after treatment in the treatment group was significantly higher than that in the control group (P<0.05). Conclusions: Nicorandil in the treatment of CSF can effectively improve the coronary artery microcirculation and hemodynamics, with a significant efficacy.展开更多
In order to exhibit the meta-stable states, several slow-to-start rules have been investigated as modification to Nagel-Schreckenberg （NS） model. These models can reproduce some realistic phenomena which are absent ...In order to exhibit the meta-stable states, several slow-to-start rules have been investigated as modification to Nagel-Schreckenberg （NS） model. These models can reproduce some realistic phenomena which are absent in the original NS model. But in these models, the size of cluster is still not considered as a useful parameter. In real traffic, the slow-to-start motion of a standing vehicle often depends on the degree of congestion which can be measured by the clusters＇ size. According to this idea, we propose a cluster-size dependent slow-to-start model based on the speed- dependent slow-to-start rule （VDR） model. It gives expected results through simulations. Comparing with the VDR model, our new model has a better traffic efficiency and shows richer complex characters.展开更多
Interstitial fluid plays a vital role in drug delivery and tumour treatment.However,few non-invasive measurement methods are available for measuring low-velocity biological fluid flow.Therefore,this study aimed to dev...Interstitial fluid plays a vital role in drug delivery and tumour treatment.However,few non-invasive measurement methods are available for measuring low-velocity biological fluid flow.Therefore,this study aimed to develop a novel technology called interstitial flow velocity-MRI.The interstitial flow velocity-MRI sequence consists of a dual inversion recovery preparation and an improved stimulated echo sequence(ISTE)combined with phase-contrast MRI.A homemade flow phantom was used to assess the feasibility and sensitivity of interstitial flow velocity-MRI.In addition,xenografts of female BALB/c mouse models of 4T1 breast cancer administered losartan(40 mg/kg)or saline(n?6)were subjected to imaging on a 7.0 T scanner to assess the in vivo interstitial fluid flow velocity.The results showed a significant correlation(P<0.001)between the theoretical velocities and velocities measured using the flow phantom.Interstitial flow velocity-MRI could detect a velocity as low as 10.21±2.65 mm/s with a spatial resolution of 0.313 mm.The losartan group had a lower mean interstitial fluid velocity than the control group(85±16 vs 113±24 mm/s).In addition,compared to the saline treatment,losartan treatment reduced the proportion of collagen fibres by 10%and 12%in the Masson and Sirius red staining groups,respectively.Interstitial flow velocity-MRI has the potential to determine interstitial fluid flow velocity non-invasively and exhibits an intuitive velocity map.展开更多
文摘Slow coronary flow phenomenon(SCFP) is an angiographic observation characterized by delayed distal vessel opacifi-cation in the absence of significant epicardial coronary disease. Only limited studies have been focused on the etiologies,clinical manifestations and treatment of this unique angiographic phenomenon. In our case report,we described an 85-year-old man who came with significant ST segment elevation in leads V1-V4 and V3R-V5R without increase in myocardial enzyme. The patient also developed respiratory failure requiring intubation and mechanical ventilation. Coronary angiography revealed only mild atherosclerosis without spasm or thromboembolic occlusion. Slow flow was seen in all coronary arteries,especially in the left anterior descending and right coronary arteries. This case speculated that transmural myocardial ischemia with ST segment elevation might be resulted from slow coronary flow. Transmural myocardial ischemia can occur owing to abnormalities of the coronary microcirculation.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50908064 and 51208158)the 46thChina Postdoctoral Science Foundation(Grant No.20090460912)
文摘Urban water supply network is a modern urban survival and development of the infrastructure of a city,and its normal running conditions have important significance. The actual hydraulic process in the variableload water distribution networks can be treated as the slow transient flow which belongs to the unsteady flow. This paper analyzes the multi-loops network slow transient model based on graph theory,and the link flow matrix is treated as the variables of the discrete solution model to simulate the process of the slow transient flow in the network. With the simulation of hydraulic regime in an actual pipe network,the changing laws of the flow in the pipes,nodal hydraulic heads and other hydraulic factors with the passage of time are obtained. Since the transient processes offer much more information than a steady process,the slow transient theory is not only practical on analyzing the hydraulic condition of the network,but also on identifying hydraulic resistance coefficients of pipes and detecting the leakage in networks.
文摘Objective:To explore the effect of nicorandil on the coronary artery microcirculation and hemodynamics in patients with coronary slow flow (CSF).Methods: A total of 86 patients with CSF who were admitted in our hospital were included in the study and randomized into the treatment group and the control group with 43 cases in each group. The patients in the control group were given aspirin, HMG-CoA reductase inhibitor, and ACEI. On this basis, the patients in the treatment group were given nicorandil. The patients in the two groups were continuously treated for 6 months. The coronary artery microcirculation and hemodynamic indicators before and after treatment in the two groups were detected and compared.Results:TAT, ET-1, and hs-CRP levels, LAD, LCX, RCA, TIMI average blood flow frame count value, and IMR after treatment in the two groups were significantly reduced when compared with before treatment (P<0.05). The above indicators after treatment in the treatment group were significantly lower than those in the control group (P<0.05). FMD after treatment in the two groups was significantly elevated when compared with before treatment (P<0.05). FMD after treatment in the treatment group was significantly higher than that in the control group (P<0.05). Conclusions: Nicorandil in the treatment of CSF can effectively improve the coronary artery microcirculation and hemodynamics, with a significant efficacy.
基金Project supported by the State Key Development Program for Basic Research of China （Grant No 2006CB705500）, the National Natural Science Foundation of China （Grant Nos 10472116, 10532060, and 70571074）, the Special Research Funds for Theoretical Physics Frontier Problems （Grant Nos 10547004 and A0524701）, the Presidential Foundation of the Chinese Academy of Sciences, and the Specialized Rescarch Fund for the Doctoral Program of High Education of China.
文摘In order to exhibit the meta-stable states, several slow-to-start rules have been investigated as modification to Nagel-Schreckenberg （NS） model. These models can reproduce some realistic phenomena which are absent in the original NS model. But in these models, the size of cluster is still not considered as a useful parameter. In real traffic, the slow-to-start motion of a standing vehicle often depends on the degree of congestion which can be measured by the clusters＇ size. According to this idea, we propose a cluster-size dependent slow-to-start model based on the speed- dependent slow-to-start rule （VDR） model. It gives expected results through simulations. Comparing with the VDR model, our new model has a better traffic efficiency and shows richer complex characters.
文摘Interstitial fluid plays a vital role in drug delivery and tumour treatment.However,few non-invasive measurement methods are available for measuring low-velocity biological fluid flow.Therefore,this study aimed to develop a novel technology called interstitial flow velocity-MRI.The interstitial flow velocity-MRI sequence consists of a dual inversion recovery preparation and an improved stimulated echo sequence(ISTE)combined with phase-contrast MRI.A homemade flow phantom was used to assess the feasibility and sensitivity of interstitial flow velocity-MRI.In addition,xenografts of female BALB/c mouse models of 4T1 breast cancer administered losartan(40 mg/kg)or saline(n?6)were subjected to imaging on a 7.0 T scanner to assess the in vivo interstitial fluid flow velocity.The results showed a significant correlation(P<0.001)between the theoretical velocities and velocities measured using the flow phantom.Interstitial flow velocity-MRI could detect a velocity as low as 10.21±2.65 mm/s with a spatial resolution of 0.313 mm.The losartan group had a lower mean interstitial fluid velocity than the control group(85±16 vs 113±24 mm/s).In addition,compared to the saline treatment,losartan treatment reduced the proportion of collagen fibres by 10%and 12%in the Masson and Sirius red staining groups,respectively.Interstitial flow velocity-MRI has the potential to determine interstitial fluid flow velocity non-invasively and exhibits an intuitive velocity map.
