To investigate the cost-effectiveness of different maintenance treatments of highways in Jiangsu Province, the historical pavement maintenance records, traffic load information and pavement performance data in the pav...To investigate the cost-effectiveness of different maintenance treatments of highways in Jiangsu Province, the historical pavement maintenance records, traffic load information and pavement performance data in the pavement management system (PMS) are recorded and analyzed. Compared with the growth model, the linear model, the logarithm model and the exponential model, the cubic model has higher regression accuracy R2 and it can capture the sigmoid shape of the deterioration curve. So it is selected to simulate the pavement rotting development. The benefit over cost ratio is calculated to quantify the treatment cost- effectiveness. The analysis results show that thin hot mix asphalt (HMA) overlays and micro surfacing are more cost- effective than the. other two treatments on light and moderate traffic roads. Hot in-place recycling and thick HMA overlays have much longer service lives and greater cost-effectiveness under heavy or extra heavy traffic.展开更多
Based on the GIS technology, CITYgreen computer model was used in this paper to estimate ecological benefits of urban forest in the park of Hefei city.It used this technology to make an analysis on urban forest ecolog...Based on the GIS technology, CITYgreen computer model was used in this paper to estimate ecological benefits of urban forest in the park of Hefei city.It used this technology to make an analysis on urban forest ecological benefits. The research discussed how to use the technology of CITYgreen model developed in USA to account urban forest benefits in China. The results showed that forests in Xiaoyao Jin Park occupied about 52.62% of park land area and Xinghua Park13.00% respectively, indicating that Xiaoyaojin Park is dominated by large trees such as arbors, and Xinghua Park dominated by laws, with low coverage. Besides,the comprehensive eco-benefits of Xiaoyaojin Park and Xinghua Park were 5.150 3and 1.354 3 million yuan and per unit area eco-benefits were 144 000 and 47 400yuan/hm^2, which indicated that Xiaoyaojin Park makes the greatest contribution in ecological benefits.展开更多
The combustion process of pulverized coal injected into blast furnace involves a lot of physical and chemical reactions. Based on the combustion behaviors of pulverized coal, the conception of coal effective calorific...The combustion process of pulverized coal injected into blast furnace involves a lot of physical and chemical reactions. Based on the combustion behaviors of pulverized coal, the conception of coal effective calorific value representing the actual thermal energy provided for blast furnace was proposed. A cost performance evaluation model of coal injection was built up for the optimal selection of various kinds of coal based on effective calorific value. The model contains two indicators: coal effective calorific value which has eight sub-indicators and coal injection cost which includes four sub-indicators. In addition, the calculation principle and application of cost performance evaluation model in a Chinese large-scale iron and steel company were comprehensively introduced. The evaluation results finally confirm that this novel model is of great significance to the optimal selection of blast furnace pulverized coal.展开更多
The cutting technic for thePinus elliottii plantation of the multi-benefit management pattern in the hilly region of Jiangxi Province was studied by establishing the model of growth progress according to Richards func...The cutting technic for thePinus elliottii plantation of the multi-benefit management pattern in the hilly region of Jiangxi Province was studied by establishing the model of growth progress according to Richards function and simulating the tending cutting on computer by use of dynamic programming. The results showed that the best time for the initial thinning was at tree age of 8–10 and final cutting was at tree age of 25. The optimal thinning project was 3 times of thinning cutting including the first thinning, and the thinning time was at tree ages of 8, 12 and 16, respectively. Their thinning intensities were separately 950, 700 and 300 trunks per hectare, and the preserved density was 550 trunks per hectare until the final cutting Keywords Pinus elliottir - Multi-benefit management pattern - Richards function - Cutting technic - Dynamic programming CLC number S757.4 Document code A Foundation item: This study was supported by Natural Science Foundation of Jiangxi Province (A grant 0330023)Biography: WANG Qing-chun (1970-), male, Ph. Doctor, Senior Engineer in Academy of Forest Inventory & Planning, Jiangxi, Nanchang 330046, P.R. China.Responsible editor: Song Funan展开更多
In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly ...In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly spatial social welfare maximization problem. This interdisciplinary model relies on multiple data sources, including current wolf population and distribution information, opportunity cost to local landowners, and contingent valuation studies to determine willingness-to-pay for wolves. Economic models tend to externalize ecological concerns and ecological models often omit the complex human dimensions of conservation policy. Accordingly, this model can serve as a guide for integrating best practices from both fields. The model presented here is sufficiently general to apply to wolves in other ecosystems and to other highly interacting species such as beavers and bison. The Northern Rocky Mountain wolf was used as an example of how this economic model works, but this model can be applied far more broadly.展开更多
Industrial clusters have been an important phenomenon of the global economy. The most important reason for its becoming the focus of people's attention and the popular mode of industry programming is continuous and p...Industrial clusters have been an important phenomenon of the global economy. The most important reason for its becoming the focus of people's attention and the popular mode of industry programming is continuous and powerful competitiveness ,The article analyzes this competitiveness, and points out some problems of China's industrial clusters, which directly affects its current competitiveness and further development. Finally, we propose stone specific measures of those problems.展开更多
The ecolotogical research of enterprises' competition is the front line of current research of enterprises ' competition strategy : This text applies the competition principle of living creature in ecology to resea...The ecolotogical research of enterprises' competition is the front line of current research of enterprises ' competition strategy : This text applies the competition principle of living creature in ecology to research enterprises' competition problems .explains the ecological characterisiics of enterprises' competition, such as non-symmetry, crowded effect, density effect. competition-rejective effect, suitable resources niche and red queen effect etc., deduces the ecological model of enterprise' competition, and further analyzes enterprises' competition strategy; strategy R and strategy K. on the basis of enterprises' practices, Therefore enterprises' competition ecosystem theories have further been deepened and enriched.展开更多
Curb parking lot is a major part of city parking facility with lots of problems, especially in CCA (citycenter area and it has a lot of advantages and has much effect on dynamic traffic as well. It is therefore necess...Curb parking lot is a major part of city parking facility with lots of problems, especially in CCA (citycenter area and it has a lot of advantages and has much effect on dynamic traffic as well. It is therefore necessaryto control the scale of curb parking. Basing the whole benefits of the traffic system and considering the minimumsynthetical cost on curb parking, a optimization model is brought forward of cur. b parking planning in CCAbased on minimum generalized cost. Based on this model, the scale of curb parking can be defined reasonablyto make the whole benefits of traffic system optimum in CCA.展开更多
This paper studies the algorithm of the adaptive grid and fuzzy interacting multiple model (AGFIMM) for maneuvering target tracking, while focusing on the problems of the fixed structure multiple model (FSMM) algo...This paper studies the algorithm of the adaptive grid and fuzzy interacting multiple model (AGFIMM) for maneuvering target tracking, while focusing on the problems of the fixed structure multiple model (FSMM) algorithm's cost-efficiency ratio being not high and the Markov transition probability of the interacting multiple model (IMM) algorithm being difficult to determine exactly. This algorithm realizes the adaptive model set by adaptive grid adjustment, and obtains each model matching degree in the model set by fuzzy logic inference. The simulation results show that the AGFIMM algorithm can effectively improve the accuracy and cost-efficiency ratio of the multiple model algorithm, and as a result is suitable for enineering apolications.展开更多
Coal storing and loading have much more influence on coal quality. In the paper, a goal programming model has been constructed to determine the ideal quantity extracting from stockpile and silos and a quality control ...Coal storing and loading have much more influence on coal quality. In the paper, a goal programming model has been constructed to determine the ideal quantity extracting from stockpile and silos and a quality control model is inferred under the guidance of maximum theory of dispersed number and practice methods are given to meet production demand, with which a coal mine has achieved a better tech-economic result.展开更多
The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urba...The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urban trips. Traffic corridor is a major scenario that supports travellers to commute from suburban residential areas to central working areas. Studying their modal choice behaviour is receiving more and more interests. On one hand, it will guide the travellers to rationally choose their most economic and beneficial mode for urban trips. On the other hand, it will help traffic operators to make more appropriate policies to enhance the share of public transit in order to alleviate the traffic congestion and produce more economic and social benefits. To analyze the travel modal choice, a generalized cost model for three typical modes is first established to evaluate each different travel alternative. Then, random utility theory(RUT) and decision field theory(DFT) are introduced to describe the decision-making process how travellers make their mode choices. Further, some important factors that may influence the modal choice behaviour are discussed as well. To test the feasibility of the proposed model, a field test in Beijing was conducted to collect the real-time data and estimate the model parameters. The improvements in the test results and analysis show new advances in the development of travel mode choice on multimodal transportation networks.展开更多
To improve flood control efficiency and increase urban resilience to flooding,the impacts of forest type change on flood control in the upper reach of the Tingjiang River(URTR) were evaluated by a modified model based...To improve flood control efficiency and increase urban resilience to flooding,the impacts of forest type change on flood control in the upper reach of the Tingjiang River(URTR) were evaluated by a modified model based on the Soil Conservation Service curve number(SCS-CN) method. Parameters of the model were selected and determined according to the comprehensive analysis of model evaluation indexes. The first simulation of forest reconstruction scenario,namely a coniferous forest covering 59.35km^2 is replaced by a broad-leaved forest showed no significant impact on the flood reduction in the URTR. The second simulation was added with 61.75km^2 bamboo forest replaced by broad-leaved forest,the reduction of flood peak discharge and flood volume could be improved significantly. Specifically,flood peak discharge of 10-year return period event was reduced to 7-year event,and the reduction rate of small flood was 21%-28%. Moreover,the flood volume was reduced by 9%-14% and 18%-35% for moderate floods and small floods,respectively. The resultssuggest that the bamboo forest reconstruction is an effective control solution for small to moderate flood in the URTR,the effect of forest conversion on flood volume is increasingly reduced as the rainfall amount increases to more extreme magnitude. Using a hydrological model with scenarios analysis is an effective simulation approach in investigating the relationship between forest type change and flood control. This method would provide reliable support for flood control and disaster mitigation in mountainous cities.展开更多
The combination of either boceprevir or telaprevir with ribavirin and interferon (triple therapy) has been shown to be more effective than ribavirin+interferon (dual therapy) for the treatment of genotype 1 hepatitis ...The combination of either boceprevir or telaprevir with ribavirin and interferon (triple therapy) has been shown to be more effective than ribavirin+interferon (dual therapy) for the treatment of genotype 1 hepatitis C. Since the benefit of these treatments takes place after years, simulation models are needed to predict long-term outcomes. In simulation models, the choice of different values of yearly discount rates (e.g., 6%, 3.5%, 2%, 1.5% or 0%) influences the results, but no studies have specifically addressed this issue. We examined this point by determining the long-term benefits under different conditions on the basis of standard modelling and using quality-adjusted life years (QALYs) to quantify the benefits. In our base case scenario, we compared the long-term benefit between patients given a treatment with a 40% sustained virologic response (SVR) (dual therapy) and patients given a treatment with a 70% SVR (triple therapy), and we then examined how these specific yearly discount rates influenced the incremental benefit. The gain between a 70% SVR and a 40% SVR decreased from 0.45 QA-LYs with a 0% discount rate to 0.22 QALYs with a 6% discount rate (ratio between the two values = 2.04).Testing the other discounting assumptions confirmed that the discount rate has a marked impact on the magnitude of the model-estimated incremental benefit. In conclusion, the results of our analysis can be helpful to better interpret cost-effectiveness studies evaluating new treatment for hepatitis C.展开更多
Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm (LVA) in rabbits. Methods Acute myocardial infarction (AMI) was induced in 35 rabbits via conc...Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm (LVA) in rabbits. Methods Acute myocardial infarction (AMI) was induced in 35 rabbits via concomitant ligation of the left anterior descending (LAD) coronary artery and the circumflex (Cx) branch at the middle portion. Development of AMI was co n-firmed by ST segment elevation and akinesis of the occluded area. Echocardiography, pathological evaluation, and agar i n-tra-chamber casting were utilized to validate the formation of LVA four weeks after the surgery. Left ventricular end systolic pressure (LVESP) and diastolic pressure (LVEDP) were measured before, immediately after and four weeks after ligation. D i-mensions of the ventricular chamber, thickness of the interventricular septum (IVS) and the left ventricular posterior wall (LVPW) left ventricular end diastolic volume (LVEDV) and systolic volume (LVESV), and ejection fraction (EF) were recorded by echo-cardiography. Results Thirty one (88.6%) rabbits survived myocardial infarction and 26 of them developed aneurysm (83.9%). The mean area of aneurysm was 33.4% ± 2.4% of the left ventricle. LVEF markedly decreased after LVA formation, whereas LVEDV, LVESV and the thickness of IVS as well as the dimension of ventricular chamber from apex to mitral valve annulus significantly increased. LVESP immediately dropped after ligation and recovered to a small extent after LVA formation. LVEDP progressively increased after ligation till LVA formation. Areas in the left ventricle (LV) that underwent fibrosis included the apex, anterior wall and lateral wall but not IVS. Agar intra-chamber cast showed that the bulging of LV wall was prominent in the area of aneurysm. Conclusions Ligation of LAD and Cx at the middle portion could induce develo pment of LVA at a mean area ratio of 33.4%±2.4%which involves the apex, anterior wall and lateral wall of the LV.展开更多
The paper supposes knowledge innovation as process innovation, revises AJ model and makes Oligopolistic Markets Model of two stages. It compares profit and social welfare between firms in the condition of cooperation ...The paper supposes knowledge innovation as process innovation, revises AJ model and makes Oligopolistic Markets Model of two stages. It compares profit and social welfare between firms in the condition of cooperation and non-cooperation. It draws the conclusion that cooperative knowledge innovation can get much more benefit because of spillover effect of knowledge.展开更多
基金The Science and Technology Project of Jiangsu Provincial Communications Department(No.7621000078)
文摘To investigate the cost-effectiveness of different maintenance treatments of highways in Jiangsu Province, the historical pavement maintenance records, traffic load information and pavement performance data in the pavement management system (PMS) are recorded and analyzed. Compared with the growth model, the linear model, the logarithm model and the exponential model, the cubic model has higher regression accuracy R2 and it can capture the sigmoid shape of the deterioration curve. So it is selected to simulate the pavement rotting development. The benefit over cost ratio is calculated to quantify the treatment cost- effectiveness. The analysis results show that thin hot mix asphalt (HMA) overlays and micro surfacing are more cost- effective than the. other two treatments on light and moderate traffic roads. Hot in-place recycling and thick HMA overlays have much longer service lives and greater cost-effectiveness under heavy or extra heavy traffic.
基金Supported by Huainan Normal Univeristy Science Research Program(2013XJ66)~~
文摘Based on the GIS technology, CITYgreen computer model was used in this paper to estimate ecological benefits of urban forest in the park of Hefei city.It used this technology to make an analysis on urban forest ecological benefits. The research discussed how to use the technology of CITYgreen model developed in USA to account urban forest benefits in China. The results showed that forests in Xiaoyao Jin Park occupied about 52.62% of park land area and Xinghua Park13.00% respectively, indicating that Xiaoyaojin Park is dominated by large trees such as arbors, and Xinghua Park dominated by laws, with low coverage. Besides,the comprehensive eco-benefits of Xiaoyaojin Park and Xinghua Park were 5.150 3and 1.354 3 million yuan and per unit area eco-benefits were 144 000 and 47 400yuan/hm^2, which indicated that Xiaoyaojin Park makes the greatest contribution in ecological benefits.
基金Project(51134008)supported by the National Natural Science Foundation of ChinaProject(2012CB720401)supported by the National Basic Research Program of China
文摘The combustion process of pulverized coal injected into blast furnace involves a lot of physical and chemical reactions. Based on the combustion behaviors of pulverized coal, the conception of coal effective calorific value representing the actual thermal energy provided for blast furnace was proposed. A cost performance evaluation model of coal injection was built up for the optimal selection of various kinds of coal based on effective calorific value. The model contains two indicators: coal effective calorific value which has eight sub-indicators and coal injection cost which includes four sub-indicators. In addition, the calculation principle and application of cost performance evaluation model in a Chinese large-scale iron and steel company were comprehensively introduced. The evaluation results finally confirm that this novel model is of great significance to the optimal selection of blast furnace pulverized coal.
基金Natural Science Foundation of Jiangxi Province (A grant 0330023)
文摘The cutting technic for thePinus elliottii plantation of the multi-benefit management pattern in the hilly region of Jiangxi Province was studied by establishing the model of growth progress according to Richards function and simulating the tending cutting on computer by use of dynamic programming. The results showed that the best time for the initial thinning was at tree age of 8–10 and final cutting was at tree age of 25. The optimal thinning project was 3 times of thinning cutting including the first thinning, and the thinning time was at tree ages of 8, 12 and 16, respectively. Their thinning intensities were separately 950, 700 and 300 trunks per hectare, and the preserved density was 550 trunks per hectare until the final cutting Keywords Pinus elliottir - Multi-benefit management pattern - Richards function - Cutting technic - Dynamic programming CLC number S757.4 Document code A Foundation item: This study was supported by Natural Science Foundation of Jiangxi Province (A grant 0330023)Biography: WANG Qing-chun (1970-), male, Ph. Doctor, Senior Engineer in Academy of Forest Inventory & Planning, Jiangxi, Nanchang 330046, P.R. China.Responsible editor: Song Funan
文摘In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly spatial social welfare maximization problem. This interdisciplinary model relies on multiple data sources, including current wolf population and distribution information, opportunity cost to local landowners, and contingent valuation studies to determine willingness-to-pay for wolves. Economic models tend to externalize ecological concerns and ecological models often omit the complex human dimensions of conservation policy. Accordingly, this model can serve as a guide for integrating best practices from both fields. The model presented here is sufficiently general to apply to wolves in other ecosystems and to other highly interacting species such as beavers and bison. The Northern Rocky Mountain wolf was used as an example of how this economic model works, but this model can be applied far more broadly.
文摘Industrial clusters have been an important phenomenon of the global economy. The most important reason for its becoming the focus of people's attention and the popular mode of industry programming is continuous and powerful competitiveness ,The article analyzes this competitiveness, and points out some problems of China's industrial clusters, which directly affects its current competitiveness and further development. Finally, we propose stone specific measures of those problems.
基金Supported by Hunan Judge Committee of Philosophy and Social Science(No.0402003)and Research Item of Hainan University(No.Kyjj0409).
文摘The ecolotogical research of enterprises' competition is the front line of current research of enterprises ' competition strategy : This text applies the competition principle of living creature in ecology to research enterprises' competition problems .explains the ecological characterisiics of enterprises' competition, such as non-symmetry, crowded effect, density effect. competition-rejective effect, suitable resources niche and red queen effect etc., deduces the ecological model of enterprise' competition, and further analyzes enterprises' competition strategy; strategy R and strategy K. on the basis of enterprises' practices, Therefore enterprises' competition ecosystem theories have further been deepened and enriched.
文摘Curb parking lot is a major part of city parking facility with lots of problems, especially in CCA (citycenter area and it has a lot of advantages and has much effect on dynamic traffic as well. It is therefore necessaryto control the scale of curb parking. Basing the whole benefits of the traffic system and considering the minimumsynthetical cost on curb parking, a optimization model is brought forward of cur. b parking planning in CCAbased on minimum generalized cost. Based on this model, the scale of curb parking can be defined reasonablyto make the whole benefits of traffic system optimum in CCA.
基金Foundation item: Supported by the National Nature Science Foundation of China (No. 61074053, 61374114) and the Applied Basic Research Program of Ministry of Transport of China (No. 2011-329-225 -390).
文摘This paper studies the algorithm of the adaptive grid and fuzzy interacting multiple model (AGFIMM) for maneuvering target tracking, while focusing on the problems of the fixed structure multiple model (FSMM) algorithm's cost-efficiency ratio being not high and the Markov transition probability of the interacting multiple model (IMM) algorithm being difficult to determine exactly. This algorithm realizes the adaptive model set by adaptive grid adjustment, and obtains each model matching degree in the model set by fuzzy logic inference. The simulation results show that the AGFIMM algorithm can effectively improve the accuracy and cost-efficiency ratio of the multiple model algorithm, and as a result is suitable for enineering apolications.
文摘Coal storing and loading have much more influence on coal quality. In the paper, a goal programming model has been constructed to determine the ideal quantity extracting from stockpile and silos and a quality control model is inferred under the guidance of maximum theory of dispersed number and practice methods are given to meet production demand, with which a coal mine has achieved a better tech-economic result.
基金Project(2012CB725405)supported in part by National Basic Research Program of ChinaProject(2014BAG03B01)supported by the National Science and Technology Support Program,China+1 种基金Project(71301083)supported by the National Natural Science Foundation of ChinaProject(20131089307)supported by the Project Supported by Tsinghua University,China
文摘The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urban trips. Traffic corridor is a major scenario that supports travellers to commute from suburban residential areas to central working areas. Studying their modal choice behaviour is receiving more and more interests. On one hand, it will guide the travellers to rationally choose their most economic and beneficial mode for urban trips. On the other hand, it will help traffic operators to make more appropriate policies to enhance the share of public transit in order to alleviate the traffic congestion and produce more economic and social benefits. To analyze the travel modal choice, a generalized cost model for three typical modes is first established to evaluate each different travel alternative. Then, random utility theory(RUT) and decision field theory(DFT) are introduced to describe the decision-making process how travellers make their mode choices. Further, some important factors that may influence the modal choice behaviour are discussed as well. To test the feasibility of the proposed model, a field test in Beijing was conducted to collect the real-time data and estimate the model parameters. The improvements in the test results and analysis show new advances in the development of travel mode choice on multimodal transportation networks.
基金funded by the National Natural Science Foundation of China (Grants No.51278239)
文摘To improve flood control efficiency and increase urban resilience to flooding,the impacts of forest type change on flood control in the upper reach of the Tingjiang River(URTR) were evaluated by a modified model based on the Soil Conservation Service curve number(SCS-CN) method. Parameters of the model were selected and determined according to the comprehensive analysis of model evaluation indexes. The first simulation of forest reconstruction scenario,namely a coniferous forest covering 59.35km^2 is replaced by a broad-leaved forest showed no significant impact on the flood reduction in the URTR. The second simulation was added with 61.75km^2 bamboo forest replaced by broad-leaved forest,the reduction of flood peak discharge and flood volume could be improved significantly. Specifically,flood peak discharge of 10-year return period event was reduced to 7-year event,and the reduction rate of small flood was 21%-28%. Moreover,the flood volume was reduced by 9%-14% and 18%-35% for moderate floods and small floods,respectively. The resultssuggest that the bamboo forest reconstruction is an effective control solution for small to moderate flood in the URTR,the effect of forest conversion on flood volume is increasingly reduced as the rainfall amount increases to more extreme magnitude. Using a hydrological model with scenarios analysis is an effective simulation approach in investigating the relationship between forest type change and flood control. This method would provide reliable support for flood control and disaster mitigation in mountainous cities.
文摘The combination of either boceprevir or telaprevir with ribavirin and interferon (triple therapy) has been shown to be more effective than ribavirin+interferon (dual therapy) for the treatment of genotype 1 hepatitis C. Since the benefit of these treatments takes place after years, simulation models are needed to predict long-term outcomes. In simulation models, the choice of different values of yearly discount rates (e.g., 6%, 3.5%, 2%, 1.5% or 0%) influences the results, but no studies have specifically addressed this issue. We examined this point by determining the long-term benefits under different conditions on the basis of standard modelling and using quality-adjusted life years (QALYs) to quantify the benefits. In our base case scenario, we compared the long-term benefit between patients given a treatment with a 40% sustained virologic response (SVR) (dual therapy) and patients given a treatment with a 70% SVR (triple therapy), and we then examined how these specific yearly discount rates influenced the incremental benefit. The gain between a 70% SVR and a 40% SVR decreased from 0.45 QA-LYs with a 0% discount rate to 0.22 QALYs with a 6% discount rate (ratio between the two values = 2.04).Testing the other discounting assumptions confirmed that the discount rate has a marked impact on the magnitude of the model-estimated incremental benefit. In conclusion, the results of our analysis can be helpful to better interpret cost-effectiveness studies evaluating new treatment for hepatitis C.
文摘Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm (LVA) in rabbits. Methods Acute myocardial infarction (AMI) was induced in 35 rabbits via concomitant ligation of the left anterior descending (LAD) coronary artery and the circumflex (Cx) branch at the middle portion. Development of AMI was co n-firmed by ST segment elevation and akinesis of the occluded area. Echocardiography, pathological evaluation, and agar i n-tra-chamber casting were utilized to validate the formation of LVA four weeks after the surgery. Left ventricular end systolic pressure (LVESP) and diastolic pressure (LVEDP) were measured before, immediately after and four weeks after ligation. D i-mensions of the ventricular chamber, thickness of the interventricular septum (IVS) and the left ventricular posterior wall (LVPW) left ventricular end diastolic volume (LVEDV) and systolic volume (LVESV), and ejection fraction (EF) were recorded by echo-cardiography. Results Thirty one (88.6%) rabbits survived myocardial infarction and 26 of them developed aneurysm (83.9%). The mean area of aneurysm was 33.4% ± 2.4% of the left ventricle. LVEF markedly decreased after LVA formation, whereas LVEDV, LVESV and the thickness of IVS as well as the dimension of ventricular chamber from apex to mitral valve annulus significantly increased. LVESP immediately dropped after ligation and recovered to a small extent after LVA formation. LVEDP progressively increased after ligation till LVA formation. Areas in the left ventricle (LV) that underwent fibrosis included the apex, anterior wall and lateral wall but not IVS. Agar intra-chamber cast showed that the bulging of LV wall was prominent in the area of aneurysm. Conclusions Ligation of LAD and Cx at the middle portion could induce develo pment of LVA at a mean area ratio of 33.4%±2.4%which involves the apex, anterior wall and lateral wall of the LV.
基金Sponsored by National Natural Science Foundation of China(NSFC,70372017)
文摘The paper supposes knowledge innovation as process innovation, revises AJ model and makes Oligopolistic Markets Model of two stages. It compares profit and social welfare between firms in the condition of cooperation and non-cooperation. It draws the conclusion that cooperative knowledge innovation can get much more benefit because of spillover effect of knowledge.