Stem cells intrigue. They have the ability to divide exponentially, recreate the stem cell compartment, as well as create differentiated cells to generate tissues. Therefore, they should be natural candidates to provi...Stem cells intrigue. They have the ability to divide exponentially, recreate the stem cell compartment, as well as create differentiated cells to generate tissues. Therefore, they should be natural candidates to provide a renewable source of cells for transplantation applied in regenerative medicine. Stem cells have the capacity to generate specific tissues or even whole organs like the blood, heart, or bones. A subgroup of stem cells, the neural stem cells （NSCs）, is characterized as a self-renewing population that generates neurons and glia of the developing brain. They can be isolated, genetically manipulated and differentiated in vitro and reintroduced into a developing, adult or a pathologically altered central nervous system. NSCs have been considered for use in cell replacement therapies in various neurodegenerative diseases such as Parkinson＇s disease and Alzheimer＇s disease. Characterization of genes with tightly controlled expression patterns during differentiation represents an approach to understanding the regulation of stem cell commitment. The regulation of stem cell biology by the ATP-binding cassette （ABC） transporters has emerged as an important new field of investigation. As a major focus of stem cell research is in the manipulation of cells to enable differentiation into a targeted cell population; in this review, we discuss recent literatures on ABC transporters and stem cells, and propose an integrated view on the role of the ABC transporters, especially ABCA2, ABCA3, ABCB 1 and ABCG2, in NSCs＇ proliferation, differentiation and regulation, along with comparisons to that in hematopoietic and other stem cells.展开更多
Due to the fact that the emergency medicine distribution is vital to the quick response to urgent demand when an epidemic occurs, the optimal vaccine distribution approach is explored according to the epidemic diffusi...Due to the fact that the emergency medicine distribution is vital to the quick response to urgent demand when an epidemic occurs, the optimal vaccine distribution approach is explored according to the epidemic diffusion rule and different urgency degrees of affected areas with the background of the epidemic outbreak in a given region. First, the SIQR （susceptible, infected, quarantined,recovered） epidemic model with pulse vaccination is introduced to describe the epidemic diffusion rule and obtain the demanded vaccine in each pulse. Based on the SIQR model, the affected areas are clustered by using the self-organizing map （SOM） neutral network to qualify the results. Then, a dynamic vaccine distribution model is formulated, incorporating the results of clustering the affected areas with the goals of both reducing the transportation cost and decreasing the unsatisfied demand for the emergency logistics network. Numerical study with twenty affected areas and four distribution centers is carried out. The corresponding numerical results indicate that the proposed approach can make an outstanding contribution to controlling the affected areas with a relatively high degree of urgency, and the comparison results prove that the performance of the clustering method is superior to that of the non-clustering method on controlling epidemic diffusion.展开更多
Overlay multicast has become one of the most promising multicast solutions for IP network,and Neutral Network(NN) has been a good candidate for searching optimal solutions to the constrained shortest routing path in v...Overlay multicast has become one of the most promising multicast solutions for IP network,and Neutral Network(NN) has been a good candidate for searching optimal solutions to the constrained shortest routing path in virtue of its powerful capacity for parallel computation. Though traditional Hopfield NN can tackle the optimization problem,it is incapable of dealing with large scale networks due to the large number of neurons. In this paper,a neural network for overlay multicast tree com-putation is presented to reliably implement routing algorithm in real time. The neural network is constructed as a two-layer recurrent architecture,which is comprised of Independent Variable Neurons(IDVN) and Dependent Variable Neurons(DVN) ,according to the independence of the decision variables associated with the edges in directed graph. Compared with the heuristic routing algorithms,it is characterized as shorter computational time,fewer neurons,and better precision.展开更多
A kind of feed forward neural network with three layers was applied to detect conveyor belt fire faster. And backward propagation (BP) algorithm was used to train the network parameters. The appropriate parameters and...A kind of feed forward neural network with three layers was applied to detect conveyor belt fire faster. And backward propagation (BP) algorithm was used to train the network parameters. The appropriate parameters and architecture of network were ob- tained after training with 81 pair of data. Matlab was used to simulate and the experi- ment result shows training time is least and error reduces most rapidly when ten neu- rons were in hidden layer and momentum coefficient is equal to 0.95. Temperature, rate of temperature change, dense of carbon monoxide and rate of carbon monoxide dense change were considered as four parameters to detect the PVC belt fire in this paper. It is indicated that the network can give alarm as fire takes place about 350 s. The network can effectively detect the fire at the early stage of conveyor belt fire. At the same time, the reliability of alarm can be increased and the anti-interference capability can be en- hanced when using this network.展开更多
The P2X3 receptor plays a vital role in sensory processing and transmission. The assembly and trafficking of the P2X3 receptor are important for its function in primary sensory neurons. As an important inflammation me...The P2X3 receptor plays a vital role in sensory processing and transmission. The assembly and trafficking of the P2X3 receptor are important for its function in primary sensory neurons. As an important inflammation mediator, ATP is released from different cell types around primary sensory neurons, especially under pathological pain conditions. Here, we showthat α, β-MeATP dramatically promoted membrane delivery of the P2X3 receptor both in HEK293T celts expressing recombinant P2X3 receptor and in rat primary sensory neurons. α, β-MeATP induced P2X3 receptor-mediated Ca^2＋ influx, which further activated Ca^2＋/calmodulin-dependent protein kinase Ilec （CaMKIIα）. The N terminus of the P2X3 receptor was responsible for CaMKIleα binding, whereas Thr38s in the C terminus was phosphorylated by CaMKIIα. Thr^388 phosphorylation increased P2X3 receptor binding to caveoUn-1. CaveoUn-1 knockdown abrogated the α, β-MeATP-induced membrane insertion of the P2X3 receptor. Moreover,α, β-MeATP drove the CaMKIlec-mediated membrane coinsertion of the P2X2 receptor with the P2X3 receptor. The increased P2X3 receptors on the cell membrane that are due to Thr388 phosphorytation facilitated P2X3 receptor-mediated signal transduction. Together, our data indicate that CaMKIIoL and caveoUn-1 cooperate to drive Ugand-induced membrane delivery of the P2X3 receptor and may provide a mechanism of P2X3 receptor sensitization in pain development.展开更多
文摘Stem cells intrigue. They have the ability to divide exponentially, recreate the stem cell compartment, as well as create differentiated cells to generate tissues. Therefore, they should be natural candidates to provide a renewable source of cells for transplantation applied in regenerative medicine. Stem cells have the capacity to generate specific tissues or even whole organs like the blood, heart, or bones. A subgroup of stem cells, the neural stem cells （NSCs）, is characterized as a self-renewing population that generates neurons and glia of the developing brain. They can be isolated, genetically manipulated and differentiated in vitro and reintroduced into a developing, adult or a pathologically altered central nervous system. NSCs have been considered for use in cell replacement therapies in various neurodegenerative diseases such as Parkinson＇s disease and Alzheimer＇s disease. Characterization of genes with tightly controlled expression patterns during differentiation represents an approach to understanding the regulation of stem cell commitment. The regulation of stem cell biology by the ATP-binding cassette （ABC） transporters has emerged as an important new field of investigation. As a major focus of stem cell research is in the manipulation of cells to enable differentiation into a targeted cell population; in this review, we discuss recent literatures on ABC transporters and stem cells, and propose an integrated view on the role of the ABC transporters, especially ABCA2, ABCA3, ABCB 1 and ABCG2, in NSCs＇ proliferation, differentiation and regulation, along with comparisons to that in hematopoietic and other stem cells.
基金The National Natural Science Foundation of China (No.70671021)
文摘Due to the fact that the emergency medicine distribution is vital to the quick response to urgent demand when an epidemic occurs, the optimal vaccine distribution approach is explored according to the epidemic diffusion rule and different urgency degrees of affected areas with the background of the epidemic outbreak in a given region. First, the SIQR （susceptible, infected, quarantined,recovered） epidemic model with pulse vaccination is introduced to describe the epidemic diffusion rule and obtain the demanded vaccine in each pulse. Based on the SIQR model, the affected areas are clustered by using the self-organizing map （SOM） neutral network to qualify the results. Then, a dynamic vaccine distribution model is formulated, incorporating the results of clustering the affected areas with the goals of both reducing the transportation cost and decreasing the unsatisfied demand for the emergency logistics network. Numerical study with twenty affected areas and four distribution centers is carried out. The corresponding numerical results indicate that the proposed approach can make an outstanding contribution to controlling the affected areas with a relatively high degree of urgency, and the comparison results prove that the performance of the clustering method is superior to that of the non-clustering method on controlling epidemic diffusion.
基金the High-tech Project of Jiangsu Province (No.BG2003001).
文摘Overlay multicast has become one of the most promising multicast solutions for IP network,and Neutral Network(NN) has been a good candidate for searching optimal solutions to the constrained shortest routing path in virtue of its powerful capacity for parallel computation. Though traditional Hopfield NN can tackle the optimization problem,it is incapable of dealing with large scale networks due to the large number of neurons. In this paper,a neural network for overlay multicast tree com-putation is presented to reliably implement routing algorithm in real time. The neural network is constructed as a two-layer recurrent architecture,which is comprised of Independent Variable Neurons(IDVN) and Dependent Variable Neurons(DVN) ,according to the independence of the decision variables associated with the edges in directed graph. Compared with the heuristic routing algorithms,it is characterized as shorter computational time,fewer neurons,and better precision.
文摘A kind of feed forward neural network with three layers was applied to detect conveyor belt fire faster. And backward propagation (BP) algorithm was used to train the network parameters. The appropriate parameters and architecture of network were ob- tained after training with 81 pair of data. Matlab was used to simulate and the experi- ment result shows training time is least and error reduces most rapidly when ten neu- rons were in hidden layer and momentum coefficient is equal to 0.95. Temperature, rate of temperature change, dense of carbon monoxide and rate of carbon monoxide dense change were considered as four parameters to detect the PVC belt fire in this paper. It is indicated that the network can give alarm as fire takes place about 350 s. The network can effectively detect the fire at the early stage of conveyor belt fire. At the same time, the reliability of alarm can be increased and the anti-interference capability can be en- hanced when using this network.
文摘The P2X3 receptor plays a vital role in sensory processing and transmission. The assembly and trafficking of the P2X3 receptor are important for its function in primary sensory neurons. As an important inflammation mediator, ATP is released from different cell types around primary sensory neurons, especially under pathological pain conditions. Here, we showthat α, β-MeATP dramatically promoted membrane delivery of the P2X3 receptor both in HEK293T celts expressing recombinant P2X3 receptor and in rat primary sensory neurons. α, β-MeATP induced P2X3 receptor-mediated Ca^2＋ influx, which further activated Ca^2＋/calmodulin-dependent protein kinase Ilec （CaMKIIα）. The N terminus of the P2X3 receptor was responsible for CaMKIleα binding, whereas Thr38s in the C terminus was phosphorylated by CaMKIIα. Thr^388 phosphorylation increased P2X3 receptor binding to caveoUn-1. CaveoUn-1 knockdown abrogated the α, β-MeATP-induced membrane insertion of the P2X3 receptor. Moreover,α, β-MeATP drove the CaMKIlec-mediated membrane coinsertion of the P2X2 receptor with the P2X3 receptor. The increased P2X3 receptors on the cell membrane that are due to Thr388 phosphorytation facilitated P2X3 receptor-mediated signal transduction. Together, our data indicate that CaMKIIoL and caveoUn-1 cooperate to drive Ugand-induced membrane delivery of the P2X3 receptor and may provide a mechanism of P2X3 receptor sensitization in pain development.
