Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborh...Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborhood match method using genetic algorithm is used to conceal the error blocks. Experimental results show that the searching space can be greatly reduced by using genetic algorithm compared with exhaustive searching method, and good image quality is achieved. The peak signal noise ratios(PSNRs) of the restored images are increased greatly.展开更多
To improve design capabilities for the knitted fabric pattern,a preliminary study is carried out for the design method.Based on mathematical theory,pattern could be created automatically by computer with inputting dif...To improve design capabilities for the knitted fabric pattern,a preliminary study is carried out for the design method.Based on mathematical theory,pattern could be created automatically by computer with inputting different parameters for mathematical functions.The knitted fabric simulation is realized by M1 CAD pattern preparation system of STOLL Company.In the pattern,different color unit is replaced by obverse stitch with different color,or by obverse stitch and reverse stitch with the same color separately,after that the effects of knitted fabrics could be simulated.Designing with this method,it would not only help to acquire a great of diversity patterns,but also improve design efficiency and save cost.展开更多
In this paper, an efficient Cyclic Prefix (CP) reconstruction scheme is proposed for Single-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter. By ...In this paper, an efficient Cyclic Prefix (CP) reconstruction scheme is proposed for Single-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter. By utilizing a decision feedback filter to cancel the residual InterSymbol Interference (ISI) in the equalized signal, the proposed scheme can effectively lower the low bound of performance for the CP reconstruction schemes and can greatly improve the Bit Error P^te (BER) performance of SC-FDE systems. In addition, the existing methods and the proposed scheme are also optimized. It is shown in the simulation results that, when the Signal-to-Noise Ratio (SNR) exceeds a certain threshold, the proposed scheme can achieve the low bound of performance for the existing methods. Moreover, by increasing the number of iteration or through optimization, the low bound can be outperformed.展开更多
In this paper, a two-level Bregman method is presented with graph regularized sparse coding for highly undersampled magnetic resonance image reconstruction. The graph regularized sparse coding is incorporated with the...In this paper, a two-level Bregman method is presented with graph regularized sparse coding for highly undersampled magnetic resonance image reconstruction. The graph regularized sparse coding is incorporated with the two-level Bregman iterative procedure which enforces the sampled data constraints in the outer level and updates dictionary and sparse representation in the inner level. Graph regularized sparse coding and simple dictionary updating applied in the inner minimization make the proposed algorithm converge with a relatively small number of iterations. Experimental results demonstrate that the proposed algorithm can consistently reconstruct both simulated MR images and real MR data efficiently, and outperforms the current state-of-the-art approaches in terms of visual comparisons and quantitative measures.展开更多
AIM: To study the protective effect of eukaryotic expression plasmid encoding augmenter of liver regeneration (ALR) on acute hepatic injury and hepatic failure in rats. METHODS: The PCR-amplified ALR gene was recombin...AIM: To study the protective effect of eukaryotic expression plasmid encoding augmenter of liver regeneration (ALR) on acute hepatic injury and hepatic failure in rats. METHODS: The PCR-amplified ALR gene was recombined with pcDNA3 plasmid, and used to treat rats with acute hepatic injury. The rats with acute hepatic injury induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl4) were randomly divided into saline control group and recombinant pcDNA3-ALR plasmid treatment groups. Recombinant pcDNA3-ALR plasmid DNA (50 or 200 μg/kg) was injected into the rats with acute hepatic injury intravenously, intraperitoneally, or intravenously and intraperitoneally in combination 4 h after CCl4 administration, respectively. The recombinant plasmid was injected once per 12 h into all treatment groups four times, and the rats were decapitated 12 h after the last injection. Hepatic histopathological alterations were observed after HE staining, the expression of proliferating cell nuclear antigen (PCNA) in liver tissue was detected by immunohistochemical staining, and the level of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was determined by biochemical method. The recombinant plasmid DNA (200 μg/kg) and saline were intraperitoneally injected into the rats with acute hepatic failure induced by intraperitoneal injection of 4 mL/kg 50% CCl4 after 4 h of CCl4 administration, respectively. Rats living over 96 h were considered as survivals.RESULTS: The sequence of ALR cDNA of recombinant pcDNA3-ALR plasmid was accordant with the reported sequence of rat ALR cDNA. After the rats with acute hepatic injury were treated with recombinant pcDNA3-ALR plasmid, the degree of liver histopathological injury markedly decreased. The pathologic liver tissues, in which hepatic degeneration and necrosis of a small amount of hepatocytes and a large amount of infiltrating inflammatory cells were observed, and they became basically normal in the most effective group after four times of injection of recombinant pcDNA3-ALR plasmid. The indexes of PCNA significantly increased in the recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The level of serum AST and ALT remarkably reduced in recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The results showed that the effect of 200 μg/kg recombinant pcDNA3-ALR plasmid in the rats with acute liver injury was stronger than that of 50μg/kg pcDNA3-ALR DNA.The effect of intravenous injection of recombinant pcDNA3ALR plasmid was better. After the rats with acute hepatic failure were treated with recombinant pcDNA3-ALR plasmid,the survival rate (40%) significantly increased in treatment groups compared to control group (15%, P<0.01).CONCLUSION: The ALR gene may play an important role in relieving acute hepatic injury and hepatic failure by promoting hepatic cell proliferation and reducing level ofAST and ALT in CCl4-intoxicated rats.展开更多
For sustainable development, a reduction in energy demand is essential. This could be achieved through improving energy efficiency, effective energy conservation and management. The weather conditions of a given regio...For sustainable development, a reduction in energy demand is essential. This could be achieved through improving energy efficiency, effective energy conservation and management. The weather conditions of a given region are the most important consideration for the proper design of space AC (Air Conditioning) systems. In this study, the typical meteorological year and climatic database of Turkey for the energy analysis of buildings were generated by SQL (Structured Query Language) database programmimg language. The Finkelstein-Schafer statistical method was applied to analyze the hourly measured weather data of a 23-year period (1989-2012) and select representative TMMs (Typical Meteorological Months). The selection criteria were based on 13 meteorological parameters. These parameters are the daily mean, maximum and minimum values and ranges of temperature, dew-point and wind velocity and the daily values of global solar radiation. According to results of TMY (Typical Meteorological Year), climatic database of Turkey including daily or hourly climate variables was created in SQL data tables.展开更多
To study the expression characteristic of Japanese encephalitis virus (JEV) prME and E proteins and the efficacy of DNA immunization by different recombinant plasmids containing JEV prME (2001 bp) and E (1500 bp) gene...To study the expression characteristic of Japanese encephalitis virus (JEV) prME and E proteins and the efficacy of DNA immunization by different recombinant plasmids containing JEV prME (2001 bp) and E (1500 bp) genes, two recombinants (pJME and pJE) containing JEV prME and E genes fused with FLAG were constructed and then transfected into HepG2 and COS-1 cells by liposome fusion. The expression feature of FLAG-prME (about 72 kDa) and FLAG-E (about 54 kDa) proteins in transfected cells were analyzed by Western blot and two antibody systems (anti-FLAG and anti-E). BALB/c mice were immunized with 100 μg of two kinds of recombinants by intramuscular injection, and JEV JaGAr-01 strains (10 5 PFU/100 μl)were given to BALB/c mice by intraperioneal injection 3 wk after twice DNA immunization by a lethal virus challenge. BALB/c mice were observed for 21 days after challenge. 80% plaque reduction neutralization test was performed to titrate neutralization antibody before and after viral challenge. It was found that the expression of proteins associated with pJME and pJE was determined in transfected cells with anti-FLAG and a new protein of 11 kDa was detected in HepG2 and COS-1 cells transfected with pJME. Only E (53 kDa) protein was identified as transfected with pJME using anti-E. Higher level of neutralization antibodies and the efficacy of protective immunity were induced with pJME immunization, and were similar to those induced by inactivated Japanese encephalitis vaccine, but were better than those induced with pJE. It concludes that the expression level from prM to E proteins of JEV is different in vitro, and the in vitro expression efficiency of pJME was better than that of pJE. FLAG-prME protein expressed by pJME could be cleaved by peptidase from host. The efficacy of DNA immunization is correlated to the expression characterization of related proteins expressed in vitro.展开更多
This paper which is directed to constructing the cognitive model of knowledge acquisition in view of the increasing need of globalization-oriented study, points out features of globalization-oriented study, and propos...This paper which is directed to constructing the cognitive model of knowledge acquisition in view of the increasing need of globalization-oriented study, points out features of globalization-oriented study, and proposes the importance and necessity for constructing the CMKAGS (cognitive model of knowledge acquisition in globalization-oriented study) which includes attention, background knowledge, and chunking memory that involves semantic chunking, information encoding as well as choice of information encoding. The cognitive model of knowledge acquisition in question aims at helping e-learners to memorize their learned knowledge and improve their studies effectively and efficiently, whether they study in enhanced conditions or in natural conditions展开更多
This paper used the virtual reality modeling language (VRML) to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual reali...This paper used the virtual reality modeling language (VRML) to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.展开更多
The disturbance torque generated via solar array drive assembly(SADA) can significantly degrade the key performance of satellite.The discussed SADA is composed of a two-phase hybrid stepping motor and a set of two-sta...The disturbance torque generated via solar array drive assembly(SADA) can significantly degrade the key performance of satellite.The discussed SADA is composed of a two-phase hybrid stepping motor and a set of two-stage straight gear reducer. Firstly, the vibration equation of the two-phase hybrid stepping motor is established via simplifying and linearizing the electromagnetic torque.Secondly, based on the vibration equation established, the disturbance torque model of SADA is created via force analysis and force system simplification. Thirdly, for precisely ground measuring the disturbance torque aroused by SADA, a measurement system,including a strain micro-vibrations measurement platform(SMMP) and a set of gravity unloading device(GUD), is designed.Fourthly, the proposed disturbance torque model is validated by measuring and simulating the disturbance torque produced via SADA driving rigid load through GUD. The results indicate that, the proposed disturbance torque model holds the ability to describe the disturbance torque caused by SADA with high precision. Finally, the disturbance torque emitted by SADA driving a flexible load, designed to simulate solar array, is modeled and simulated via using fixed-interface mode synthesis method(FIMSM). All the conclusions drawn from this article do have a meaningful help for studying the disturbance torque produced by SADA driving solar array on orbit.展开更多
The research on the use of fiber sensors based on long-period fiber gratings inscribed by CO2 laser mid-infrared radiation has increased in the last years. In this paper, a set of analytical expressions are used to mo...The research on the use of fiber sensors based on long-period fiber gratings inscribed by CO2 laser mid-infrared radiation has increased in the last years. In this paper, a set of analytical expressions are used to model the interaction between laser radiation and an optical fiber and to determine the resulting refractive index change. Thermal and residual stress analysis is exemplified for a standard single mode fiber, demonstrating the capability of these models to point out the necessary parameters to achieve proper optical fiber devices based on long period fiber gratings. Experimental results are also presented.展开更多
β-carotene ketolase and β-carotene hydroxylase encoded by bkt and bch, respectively, are key enzymes required for astaxanthin biosynthesis in Haematococcu pluvialis 34-1n. Two expression vectors containing cDNA sequ...β-carotene ketolase and β-carotene hydroxylase encoded by bkt and bch, respectively, are key enzymes required for astaxanthin biosynthesis in Haematococcu pluvialis 34-1n. Two expression vectors containing cDNA sequences of bkt and bch were constructed and co-transformed into cell-wall-deficient Chlamydomonas reinhardtii CC-849. Transgenic algae were screened on TAP agar plates containing 10 gg mL 1 Zeomycin. PCR-Southern analysis showed that bkt and bch were integrated into the genomes of C. reinhardtii. Transcripts of bkt and bch were further confirmed by RT-PCR-Southern analysis. Compared with the wild type, transgenic algae produced 29.04% and 30.27% more carotenoids and xanthophylls, respectively. Moreover, the transgenic algae could accumulate 34% more astaxanthin than wild type. These results indicate that foreign bkt and bch genes were successfully translated into β-carotene ketolase and β-carotene hydroxylase, which were responsible for catalyzing the biosynthesis of astaxanthin in transgenic algae.展开更多
In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding base...In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding based on the analysis of simulation and modeling have given rise to electrophysiological models of periglomerular cells,which have an important role in the understanding of the biology of these cells.In this review we provide a brief introduction to the anatomy of the olfactory system and the cell types in the olfactory bulb.We elaborate on the latest progress in the study of the heterogeneity of periglomerular cells based on different classification criteria,such as molecular markers,structure,ion channels and action potentials.Then,we discuss the several existing electrophysiological models of periglomerular cells,and we highlight the problems and defects of these models.Finally,considering our present work,we propose a future direction for electrophysiological investigations of periglomerular cells and for the modeling of periglomerular cells and olfactory information encoding.展开更多
文摘Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborhood match method using genetic algorithm is used to conceal the error blocks. Experimental results show that the searching space can be greatly reduced by using genetic algorithm compared with exhaustive searching method, and good image quality is achieved. The peak signal noise ratios(PSNRs) of the restored images are increased greatly.
基金Doctoral fundation of Tianjin Polytechnic University,China(No.029066)
文摘To improve design capabilities for the knitted fabric pattern,a preliminary study is carried out for the design method.Based on mathematical theory,pattern could be created automatically by computer with inputting different parameters for mathematical functions.The knitted fabric simulation is realized by M1 CAD pattern preparation system of STOLL Company.In the pattern,different color unit is replaced by obverse stitch with different color,or by obverse stitch and reverse stitch with the same color separately,after that the effects of knitted fabrics could be simulated.Designing with this method,it would not only help to acquire a great of diversity patterns,but also improve design efficiency and save cost.
文摘In this paper, an efficient Cyclic Prefix (CP) reconstruction scheme is proposed for Single-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter. By utilizing a decision feedback filter to cancel the residual InterSymbol Interference (ISI) in the equalized signal, the proposed scheme can effectively lower the low bound of performance for the CP reconstruction schemes and can greatly improve the Bit Error P^te (BER) performance of SC-FDE systems. In addition, the existing methods and the proposed scheme are also optimized. It is shown in the simulation results that, when the Signal-to-Noise Ratio (SNR) exceeds a certain threshold, the proposed scheme can achieve the low bound of performance for the existing methods. Moreover, by increasing the number of iteration or through optimization, the low bound can be outperformed.
基金Supported by the National Natural Science Foundation of China(No.61261010No.61362001+7 种基金No.61365013No.61262084No.51165033)Technology Foundation of Department of Education in Jiangxi Province(GJJ13061GJJ14196)Young Scientists Training Plan of Jiangxi Province(No.20133ACB21007No.20142BCB23001)National Post-Doctoral Research Fund(No.2014M551867)and Jiangxi Advanced Project for Post-Doctoral Research Fund(No.2014KY02)
文摘In this paper, a two-level Bregman method is presented with graph regularized sparse coding for highly undersampled magnetic resonance image reconstruction. The graph regularized sparse coding is incorporated with the two-level Bregman iterative procedure which enforces the sampled data constraints in the outer level and updates dictionary and sparse representation in the inner level. Graph regularized sparse coding and simple dictionary updating applied in the inner minimization make the proposed algorithm converge with a relatively small number of iterations. Experimental results demonstrate that the proposed algorithm can consistently reconstruct both simulated MR images and real MR data efficiently, and outperforms the current state-of-the-art approaches in terms of visual comparisons and quantitative measures.
基金Supported by the Natural Science Foundation of Hebei Province, No. 302489
文摘AIM: To study the protective effect of eukaryotic expression plasmid encoding augmenter of liver regeneration (ALR) on acute hepatic injury and hepatic failure in rats. METHODS: The PCR-amplified ALR gene was recombined with pcDNA3 plasmid, and used to treat rats with acute hepatic injury. The rats with acute hepatic injury induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl4) were randomly divided into saline control group and recombinant pcDNA3-ALR plasmid treatment groups. Recombinant pcDNA3-ALR plasmid DNA (50 or 200 μg/kg) was injected into the rats with acute hepatic injury intravenously, intraperitoneally, or intravenously and intraperitoneally in combination 4 h after CCl4 administration, respectively. The recombinant plasmid was injected once per 12 h into all treatment groups four times, and the rats were decapitated 12 h after the last injection. Hepatic histopathological alterations were observed after HE staining, the expression of proliferating cell nuclear antigen (PCNA) in liver tissue was detected by immunohistochemical staining, and the level of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was determined by biochemical method. The recombinant plasmid DNA (200 μg/kg) and saline were intraperitoneally injected into the rats with acute hepatic failure induced by intraperitoneal injection of 4 mL/kg 50% CCl4 after 4 h of CCl4 administration, respectively. Rats living over 96 h were considered as survivals.RESULTS: The sequence of ALR cDNA of recombinant pcDNA3-ALR plasmid was accordant with the reported sequence of rat ALR cDNA. After the rats with acute hepatic injury were treated with recombinant pcDNA3-ALR plasmid, the degree of liver histopathological injury markedly decreased. The pathologic liver tissues, in which hepatic degeneration and necrosis of a small amount of hepatocytes and a large amount of infiltrating inflammatory cells were observed, and they became basically normal in the most effective group after four times of injection of recombinant pcDNA3-ALR plasmid. The indexes of PCNA significantly increased in the recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The level of serum AST and ALT remarkably reduced in recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The results showed that the effect of 200 μg/kg recombinant pcDNA3-ALR plasmid in the rats with acute liver injury was stronger than that of 50μg/kg pcDNA3-ALR DNA.The effect of intravenous injection of recombinant pcDNA3ALR plasmid was better. After the rats with acute hepatic failure were treated with recombinant pcDNA3-ALR plasmid,the survival rate (40%) significantly increased in treatment groups compared to control group (15%, P<0.01).CONCLUSION: The ALR gene may play an important role in relieving acute hepatic injury and hepatic failure by promoting hepatic cell proliferation and reducing level ofAST and ALT in CCl4-intoxicated rats.
文摘For sustainable development, a reduction in energy demand is essential. This could be achieved through improving energy efficiency, effective energy conservation and management. The weather conditions of a given region are the most important consideration for the proper design of space AC (Air Conditioning) systems. In this study, the typical meteorological year and climatic database of Turkey for the energy analysis of buildings were generated by SQL (Structured Query Language) database programmimg language. The Finkelstein-Schafer statistical method was applied to analyze the hourly measured weather data of a 23-year period (1989-2012) and select representative TMMs (Typical Meteorological Months). The selection criteria were based on 13 meteorological parameters. These parameters are the daily mean, maximum and minimum values and ranges of temperature, dew-point and wind velocity and the daily values of global solar radiation. According to results of TMY (Typical Meteorological Year), climatic database of Turkey including daily or hourly climate variables was created in SQL data tables.
基金This research was supported by a grant for project research from high Technology center of Kanazawa Medical University(H2000 2)
文摘To study the expression characteristic of Japanese encephalitis virus (JEV) prME and E proteins and the efficacy of DNA immunization by different recombinant plasmids containing JEV prME (2001 bp) and E (1500 bp) genes, two recombinants (pJME and pJE) containing JEV prME and E genes fused with FLAG were constructed and then transfected into HepG2 and COS-1 cells by liposome fusion. The expression feature of FLAG-prME (about 72 kDa) and FLAG-E (about 54 kDa) proteins in transfected cells were analyzed by Western blot and two antibody systems (anti-FLAG and anti-E). BALB/c mice were immunized with 100 μg of two kinds of recombinants by intramuscular injection, and JEV JaGAr-01 strains (10 5 PFU/100 μl)were given to BALB/c mice by intraperioneal injection 3 wk after twice DNA immunization by a lethal virus challenge. BALB/c mice were observed for 21 days after challenge. 80% plaque reduction neutralization test was performed to titrate neutralization antibody before and after viral challenge. It was found that the expression of proteins associated with pJME and pJE was determined in transfected cells with anti-FLAG and a new protein of 11 kDa was detected in HepG2 and COS-1 cells transfected with pJME. Only E (53 kDa) protein was identified as transfected with pJME using anti-E. Higher level of neutralization antibodies and the efficacy of protective immunity were induced with pJME immunization, and were similar to those induced by inactivated Japanese encephalitis vaccine, but were better than those induced with pJE. It concludes that the expression level from prM to E proteins of JEV is different in vitro, and the in vitro expression efficiency of pJME was better than that of pJE. FLAG-prME protein expressed by pJME could be cleaved by peptidase from host. The efficacy of DNA immunization is correlated to the expression characterization of related proteins expressed in vitro.
文摘This paper which is directed to constructing the cognitive model of knowledge acquisition in view of the increasing need of globalization-oriented study, points out features of globalization-oriented study, and proposes the importance and necessity for constructing the CMKAGS (cognitive model of knowledge acquisition in globalization-oriented study) which includes attention, background knowledge, and chunking memory that involves semantic chunking, information encoding as well as choice of information encoding. The cognitive model of knowledge acquisition in question aims at helping e-learners to memorize their learned knowledge and improve their studies effectively and efficiently, whether they study in enhanced conditions or in natural conditions
文摘This paper used the virtual reality modeling language (VRML) to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.
文摘The disturbance torque generated via solar array drive assembly(SADA) can significantly degrade the key performance of satellite.The discussed SADA is composed of a two-phase hybrid stepping motor and a set of two-stage straight gear reducer. Firstly, the vibration equation of the two-phase hybrid stepping motor is established via simplifying and linearizing the electromagnetic torque.Secondly, based on the vibration equation established, the disturbance torque model of SADA is created via force analysis and force system simplification. Thirdly, for precisely ground measuring the disturbance torque aroused by SADA, a measurement system,including a strain micro-vibrations measurement platform(SMMP) and a set of gravity unloading device(GUD), is designed.Fourthly, the proposed disturbance torque model is validated by measuring and simulating the disturbance torque produced via SADA driving rigid load through GUD. The results indicate that, the proposed disturbance torque model holds the ability to describe the disturbance torque caused by SADA with high precision. Finally, the disturbance torque emitted by SADA driving a flexible load, designed to simulate solar array, is modeled and simulated via using fixed-interface mode synthesis method(FIMSM). All the conclusions drawn from this article do have a meaningful help for studying the disturbance torque produced by SADA driving solar array on orbit.
文摘The research on the use of fiber sensors based on long-period fiber gratings inscribed by CO2 laser mid-infrared radiation has increased in the last years. In this paper, a set of analytical expressions are used to model the interaction between laser radiation and an optical fiber and to determine the resulting refractive index change. Thermal and residual stress analysis is exemplified for a standard single mode fiber, demonstrating the capability of these models to point out the necessary parameters to achieve proper optical fiber devices based on long period fiber gratings. Experimental results are also presented.
基金supported by the National Natural Science Foundation of China(41176106,31470389,31470431)Shenzhen Grant Plan for Science & Technology(CXB201104210005A,JCYJ20120613112512654,JSGG20130411160539208)Guangdong Enterprise Academician Workstation(2011A090700015)
文摘β-carotene ketolase and β-carotene hydroxylase encoded by bkt and bch, respectively, are key enzymes required for astaxanthin biosynthesis in Haematococcu pluvialis 34-1n. Two expression vectors containing cDNA sequences of bkt and bch were constructed and co-transformed into cell-wall-deficient Chlamydomonas reinhardtii CC-849. Transgenic algae were screened on TAP agar plates containing 10 gg mL 1 Zeomycin. PCR-Southern analysis showed that bkt and bch were integrated into the genomes of C. reinhardtii. Transcripts of bkt and bch were further confirmed by RT-PCR-Southern analysis. Compared with the wild type, transgenic algae produced 29.04% and 30.27% more carotenoids and xanthophylls, respectively. Moreover, the transgenic algae could accumulate 34% more astaxanthin than wild type. These results indicate that foreign bkt and bch genes were successfully translated into β-carotene ketolase and β-carotene hydroxylase, which were responsible for catalyzing the biosynthesis of astaxanthin in transgenic algae.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30300083,30800248,60875078,and 81171416)the Natural Science Foundation of Zhejiang Province (Grant No.Z1080300)
文摘In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding based on the analysis of simulation and modeling have given rise to electrophysiological models of periglomerular cells,which have an important role in the understanding of the biology of these cells.In this review we provide a brief introduction to the anatomy of the olfactory system and the cell types in the olfactory bulb.We elaborate on the latest progress in the study of the heterogeneity of periglomerular cells based on different classification criteria,such as molecular markers,structure,ion channels and action potentials.Then,we discuss the several existing electrophysiological models of periglomerular cells,and we highlight the problems and defects of these models.Finally,considering our present work,we propose a future direction for electrophysiological investigations of periglomerular cells and for the modeling of periglomerular cells and olfactory information encoding.