Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes ...Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes that run through his works.His novel Never Let Me Go tells a story of a group of clones growing up in the Hailsham,who are given the mission to donate organs at birth.So,there is no doubt that they will inevitably end their lives in the process of donating organs to human beings again and again.The tragic life of clones is determined by the motivation of human to create them.展开更多
With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the pr...With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the process of their identity quest as well as role identification.Through the specific analysis,it is concluded that the clones,represented by Kathy,Tommy and Ruth,have gained self-certainty and social identity by realizing the role identity as a“carer”and a“donor”,in the meantime,they have constructed their identity as social persons with souls like ordinary people.Furthermore,the findings shows that Never Let Me Go is actually a microcosm of human’s quest for identity.Ishiguro aims to express his meditation on human life in the novel:human life is a process of seeking self-identity and social roles,and then fulfilling the obligations of the roles,which confirms Ishiguro’s internationalism that he attempts to convey his contemplation on human existence through his works.展开更多
There are lots of code clones appearing in software,which are similar code fragments with each other. In the past decades,researchers have proposed some state-of-the-art methods to detect clones. The code clones have ...There are lots of code clones appearing in software,which are similar code fragments with each other. In the past decades,researchers have proposed some state-of-the-art methods to detect clones. The code clones have showing some relationship with the evolution of software. In order to explore relationships between clones and their evolution,we propose a framework to cluster clones with a Fuzzy C-means clustering method.Firstly,we detect all the clones using Ni Cad,and build the clone genealogies for multiple versions software.Secondly,we extract some metrics to describe the clones and their evolution. Finally,we cluster all clone's vectors,which are generated with the different metrics for different proposes. Experimental results on six open source software packages have shown the relationships among the clone life,the number of change times,the clone pattern and et al. can help developers to understand clones.展开更多
Reusing code fragments by copying and pasting them with or without minor adaptation is a common activity in software development.As a result,software systems often contain sections of code that are very similar,called...Reusing code fragments by copying and pasting them with or without minor adaptation is a common activity in software development.As a result,software systems often contain sections of code that are very similar,called code clones.Code clones are beneficial in reducing software development costs and development risks.However,recent studies have indicated some negative impacts as a result.In order to effectively manage and utilize the clones,we design an approach for recommending refactoring clones based on a Bayesian network.Firstly,clone codes are detected from the source code.Secondly,the clones that need to be refactored are identified,and the static and evolutions features are extracted to build the feature database.Finally,the Bayesian network classifier is used for training and evaluating the classification results.Based on more than 640 refactor examples of five open source software developed in C,we observe a considerable enhancement.The results show that the accuracy of the approach is larger than 90%.We believe our approach will provide a more accurate and reasonable code refactoring and maintenance advice for software developers.展开更多
ALM To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97. and...ALM To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97. andbiological characteristics of the target clones selected by in vivo screening were studied.``RESULTS Two clones with high MHCC97-H and IowMHCC9--L1 metastatic potential were isolated from theparent cell line. Compared with MHCC97-L. MHCC97-H hadsmaller cell size average cell diameter 43 um vs 50 μmand faster in vitro and in vivo growth rate tumor celldoubling time was 34.2 h vs 60.0 h. The main ranges ofchromosomes were 5.5 58 in MHCC97-H and 57 62 inMHCC97-L. Boyden chamber in vitro invasion assay demonstrated that the number of penetrating cells through the artificial basement membrane was 137.5 - 11 .0) cellsfield for MHC_C99--H vs 17.7 - 6.3) field for MHCC97-L.The proportions of cells in GO Gl phase. S phase, and G_ M phase for MHCC97-H MHCC97-L were 0.56 6.65.0.28 0.25 and 0.l6 0.10, respectively, as measured by flow cytometry. The serum AFP levels in nude mice 5 wk after orthotopic implantation of tumor tissue were ( 24666 μg. L for MHCC97-H and (91- 66) μg' L 1 for MHCC97L. The pulmonary metastatic rate was 100% (10-10) vs40% 4- 10).``CONCLUSION Two clones of the same genetic background but with different biological behaviors were established, which could be valuable models for investigation on HCC metastasis.展开更多
Mapplng of low of slngle-copy sequences on plant chromosomes has proven dirricult because ofvery low frequency or slgnal detectlon. Rlce BAC Ilbrary ls belng used wldely ln rlce genome research due tolts distlnctlve a...Mapplng of low of slngle-copy sequences on plant chromosomes has proven dirricult because ofvery low frequency or slgnal detectlon. Rlce BAC Ilbrary ls belng used wldely ln rlce genome research due tolts distlnctlve advantages over other llbrary systems. In tkls study, two blotln-Iabeled rice BAC clones closelylinked to a rlce blast reslstance, green Ieaf hopper reslstance and tungro spherlcal virus resistance gene,Pi-5(t),Glh, RTSV, were in situ hybrldlred to rlce ckromosomes. They were located on the long arm andshort arm of ckromosome 4 with FL value of 40% and 100% respectively-The rrequency of signal detectionreacked 46. 8% and 59- 2%- The slgnal location were conslstent wltk the selectlve marker on rice saturatedm0Iecular map. The results demonstrated the advautages to Iocate BAC cIones to ckromosomes by in sho hybrldization and will racilitate tke rlce low of slngle-copy gene Iocation by using the BAC library.展开更多
The ultrastructure of porcine kidney(PK)-15 cells was examined after lipofectamine-aided transfection of the molecular clone of the P1 agent.PK-15 cells transfected with the tandem dimer of the P1molecular DNA clone h...The ultrastructure of porcine kidney(PK)-15 cells was examined after lipofectamine-aided transfection of the molecular clone of the P1 agent.PK-15 cells transfected with the tandem dimer of the P1molecular DNA clone had numbers of intracytoplasmic inclusions,and a few cells had intranuclear inclusions.Intracytoplasmic inclusions were round to oval and 0.1-0.3μm in diameter,and intranuclear inclusions,which were more electron dense,were of two general types:the first were round and small(0.1μm approximately)and the second were hexagonal and larger(0.4-0.8μm in diameter).Cells transfected with the tandem dimer of the P1 molecular DNA clone tested positive for P1 DNA at passage 5.This is the first report that the P1 molecular clone has infectivity in vitro and it will provide fundamental materials for further study of the biological characterization of P1.展开更多
Objective:To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone.Methods:Green tea GMB-4 clones were extracted with distilled water at 90C.Samples were eluted into the...Objective:To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone.Methods:Green tea GMB-4 clones were extracted with distilled water at 90C.Samples were eluted into the column with 10%ethanol.Subsequently,the column was eluted with95%ethanol and evaporated separately.Green tea extract was identified by thin layer chromatography.Catechins were separated by the stationary phase in column chromatography using polyamide with 10%ethanol eluent and 95%ethanol.The results of isolations were analyzed by high performance liquid chromatographic(HPLC)and LCMS/MS.Analysis of catechins by HPLC was done by external standard.Results:Fraction from 10%ethanol showed that four major peaks at retention time of1.663,2.367,2.950 and 4.890,indicated the presence of four catechins components including catechin,epicatechins,gallocatechin and epigallocatechin.Whereas,fraction from 95%ethanol showed two main peaks at retention time of 5.167 and 9.82,which indicated the presence of epigallocatechin gallate(EGCG)and epicatechin gallate(ECG).EGCG(m/z 459),epigallocatechin(m/z 307),ECG(m/z 443),and epicatechin(m/z 291)were isolated and separated successfully using HPLC and LC-MS/MS.Conclusions:The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG.Four major catechins were separated and identified by LC-MS/MS,such as EGCG,epigallocatechin,ECG and epicatechin.The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.展开更多
Bovine embryonic stem cell would be invaluable for researching the aspect of animal cloning, production transgenic animal and discussion of gene function in vitro. With the object of establishing an effective culture ...Bovine embryonic stem cell would be invaluable for researching the aspect of animal cloning, production transgenic animal and discussion of gene function in vitro. With the object of establishing an effective culture system for isolation and clone of bovine pluripotent stem cell, we cultured bovine embryos and mouse embryos including morula blastula and hatached blastula and obtained animal ICM on Primary marine embryonic fibroblast (Primary murine embryonic fibroblast, PMEF) feeder layer with tissue medium(DMEM supplemented with 15ml/100ml NBS ,0.1μmol/L Na2SeO3, 0. 1mmol/L β-mercaptoethanol, 1 000ng/ml LIF,10 ng/ml IGF, 1mmol/L necessary amino acid and 1mmol/L L-glutamine), then, we obtained mouse ICM and bovine ICM. Moreover, we isolated and cloned the 6 passage bovine ES like cells(12 cell lines) and 9 passage marine ES like cells (52 cell lines) deriving from bovine ICM and murine ICM respectively on the feeder layer of PMEF by disaggregating ICM and ES cell clones of bovine and murine into smaller clumps through digesting with 0. 125g/100ml trypsin and 0.02g/100ml EDTA and scattering with a glass needle. The pluripotency of both murine and bovine ES like cells was identified with morphological character, histochemistry identification, karyotype analysis and differentiation of ES cells in vitro or in vivo. This result showed that bovine embryonic stem cell and murine embryonic stem cell had developmental pluripotency.展开更多
Growth characteristics have complex inheritance patterns and genotype(G) by environment(E) interaction make predicting tree response to environmental changes difficult.In this study,the growth of seven poplar clones a...Growth characteristics have complex inheritance patterns and genotype(G) by environment(E) interaction make predicting tree response to environmental changes difficult.In this study,the growth of seven poplar clones at three different sites was taken as the research focus,and heights and basal diameters were investigated in the second growing season.An ANOVA showed that all main effects,site,clone number and their interactions were highly significant in the overall F-tests.The coefficients of variation and repeatability of different traits ranged from 15.5 to 43.9%and from 0.549 to 0.912,respectively.AMMI(Additive Main Effects and Multiplicative Interaction) analysis results showed that genotype,environment and G × E interaction were significantly highly correlated.The stability analysis indicated that different clones showed different growth traits on different sites,which suggests that elite clones should be selected separately for different sites.Based on the growth traits,under a 10% selection rate,three clones were selected for different sites and the genetic gains of growth traits ranged from 4.7 to 11.2%.The three selected clones could be used to establish plantations in the future in different sites.展开更多
Effects of seven planting densities on the growth and tree form of nine 5-year-old new clones in Populus tomentosa were studied. The plantations, arranged with completely random block design, were located in Wuzhi Cou...Effects of seven planting densities on the growth and tree form of nine 5-year-old new clones in Populus tomentosa were studied. The plantations, arranged with completely random block design, were located in Wuzhi County, Henan Province. Results indicated that effects of planting density on the diameter at breast height (DBH), individual volume and growing stock increment of all new clones in P. tomentosa were significant at the 1% level of probability, effects of planting density on the tree height increment of new clones B2 and B31 and on the live branches height (LBH) increment of new clones B5 and B30 were significant at the 5% level of probability, while the interaction between planting density and clone was not significant at the 5% level of probability. It was concluded that the degree of differences among new clones within the same planting density was different with different planting densities and traits. For short rotation industrial timber, clones B1, B3, B4, B5, B7, B9, B31 were suitable with the density of 1 0002 500 trees per hectare, while for bigger diameter timber, clones B1, B3, B4, B7, B9, B31 could be used with the planting density of 660833 trees per hectare. Clonal repeatability was also different in different planting densities.展开更多
In China, the total annual production of cultured Laminaria japonica reached half million tons in dry weight there few years. The routine sporeling culture technique conducted in the greenhouse took at least three and...In China, the total annual production of cultured Laminaria japonica reached half million tons in dry weight there few years. The routine sporeling culture technique conducted in the greenhouse took at least three and half months. In such a case, sometimes the sporelings died within a few days due to destructive diseases. In Order to overcome the mentioned problems, a new sporeling culture technique, the clone technique, is developed. The method includes three stead: (1) Gametophyte clone culture. The spores and the gametophytes are cloned in flasks under favorable environments. (2) Sporeling cul ture. Male and female clones are crushed and spread onto a frame to allow the gametophytes to attach to the substrata. The frames are cultured in tanks, and the sporophytes reach 1 cm in length within one and a half months. (3) Outgrowing of the plant. The frames are put in the open sea when seawater temperature decreased to 20℃. After one month, the sporelings are large enough to be transplanted. It is concluded that the clone technique has the following advantages: (1)Large amount of clones can be produced in a short period of time. (2) Clone seeding method makes it free from the biological rhythm, one can seed the plant anytime all the year round. (3) It takes only one and a half months to complete the process of sporeling cultivation in the greenhouse. At present, this technique is used in the breeding of new strains of Laminaria.展开更多
Guava (Psidium guajava L.), a tropical fruit, belongs to Myrtaceae family. Leaves and fruits of guava have been reported to have an anti-diarrheal, hypoglycemic, lipid lowering, anti-bacterial in addition to antioxida...Guava (Psidium guajava L.), a tropical fruit, belongs to Myrtaceae family. Leaves and fruits of guava have been reported to have an anti-diarrheal, hypoglycemic, lipid lowering, anti-bacterial in addition to antioxidant activities. The aim of this study was to investigate several guava leaf extract cytotoxic effects on healthy clone 9 liver cells and its hepatoprotective effects on ethanol-induced heap-toxicity. It was discovered that when the clone 9 liver cells were treated with guava (Psidium guajava Linn.) extracts for 24 hours, there was no retardation of growth as well as when ethanol and acetone extracts at low concentrations 100 μg/mL and 50 μg/mL were administered however cytototoxic effects were detected at higher concentrations. Water and hot water extracts in concentrations lower than or equal to 500 μg/mL revealed no cytotoxic effects. Injury induction to healthy clone 9 liver cells using 5% alcohol concentration for 30 minutes revealed the hepatoprotective properties of guava (Psidium guajava Linn.) extracts. This was significant in concentrations of 100 μg/mL or lower for ethanol and all concentrations for hot water extracts. Hot water extracts showed higher hepatoprotective and lower cytotoxic properties than other extracts.展开更多
Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microf...Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microflora distribution;however, here we analyzed the bacterial diversity in colonic mucus from UC patients receiving colectomy surgery and control patients. The diversity of microflora was investigated using a combination of terminal restriction fragment length polymorphism (T-RFLP) and clone library analyses of the 16S rRNA gene sequences. In the T-RFLP analysis, the number of terminal restriction fragments (T-RFs) decreased significantly in UC patients when compared to control samples. Also in the clone library analysis, the number of operational taxonomic units (OTU) and the Shannon diversity index were reduced significantly in UC patients. These molecular analyses reveal an overall dysbiosis in UC patients. No specific pathogen was found, and a strong negative correlation in relative abundance of bacterial populations was observed between the phyla Bacteroidetes and Firmicutes in the UC patients. This is the first report showing a significant correlation between these two phyla, which may be important characteristics in the pathogenesis of UC.展开更多
We studied the variability in longitudinal growth strains and wood basic density in five-year old trees from five clones (one tree per clone) of Eucalyptus tereticornis. Mean longitudinal growth strain in clones range...We studied the variability in longitudinal growth strains and wood basic density in five-year old trees from five clones (one tree per clone) of Eucalyptus tereticornis. Mean longitudinal growth strain in clones ranged from 466 to 876 μm. There was a significant difference between clones in growth strains and wood basic density. Clone 10 exhibited maximum growth strains and basic density, whereas clone 3 and clone 7 exhibited minimum growth strains and basic density, respectively. Within a tree, the growth strain variation with tree height was high but statistically insignificant while within tree variation in basic density was very small. There was no specific trend in variation in either strain or density within a tree. There was 5% 200% difference in growth strain on opposite sides of the logs. However two strains showed a strong positive correlation. There was a moderate positive association of wood basic density and mean growth strains in logs. The variation around the periphery emphasize the need to measure strain more than one, preferably on opposite sides at the same height, on a tree to know the mean strain level for the purpose of selection of clones.展开更多
文摘Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes that run through his works.His novel Never Let Me Go tells a story of a group of clones growing up in the Hailsham,who are given the mission to donate organs at birth.So,there is no doubt that they will inevitably end their lives in the process of donating organs to human beings again and again.The tragic life of clones is determined by the motivation of human to create them.
文摘With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the process of their identity quest as well as role identification.Through the specific analysis,it is concluded that the clones,represented by Kathy,Tommy and Ruth,have gained self-certainty and social identity by realizing the role identity as a“carer”and a“donor”,in the meantime,they have constructed their identity as social persons with souls like ordinary people.Furthermore,the findings shows that Never Let Me Go is actually a microcosm of human’s quest for identity.Ishiguro aims to express his meditation on human life in the novel:human life is a process of seeking self-identity and social roles,and then fulfilling the obligations of the roles,which confirms Ishiguro’s internationalism that he attempts to convey his contemplation on human existence through his works.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61173021)
文摘There are lots of code clones appearing in software,which are similar code fragments with each other. In the past decades,researchers have proposed some state-of-the-art methods to detect clones. The code clones have showing some relationship with the evolution of software. In order to explore relationships between clones and their evolution,we propose a framework to cluster clones with a Fuzzy C-means clustering method.Firstly,we detect all the clones using Ni Cad,and build the clone genealogies for multiple versions software.Secondly,we extract some metrics to describe the clones and their evolution. Finally,we cluster all clone's vectors,which are generated with the different metrics for different proposes. Experimental results on six open source software packages have shown the relationships among the clone life,the number of change times,the clone pattern and et al. can help developers to understand clones.
基金This work was supported by the National Natural Science Foundation(61363017)of China.The author is Liu,D.S.and the website is https://isisn.nsfc.gov.cn.
文摘Reusing code fragments by copying and pasting them with or without minor adaptation is a common activity in software development.As a result,software systems often contain sections of code that are very similar,called code clones.Code clones are beneficial in reducing software development costs and development risks.However,recent studies have indicated some negative impacts as a result.In order to effectively manage and utilize the clones,we design an approach for recommending refactoring clones based on a Bayesian network.Firstly,clone codes are detected from the source code.Secondly,the clones that need to be refactored are identified,and the static and evolutions features are extracted to build the feature database.Finally,the Bayesian network classifier is used for training and evaluating the classification results.Based on more than 640 refactor examples of five open source software developed in C,we observe a considerable enhancement.The results show that the accuracy of the approach is larger than 90%.We believe our approach will provide a more accurate and reasonable code refactoring and maintenance advice for software developers.
基金Supportod ty the State Key Basic Research Program Grant G1998051211 the Fund for Leading Specialty of Shanghai Metropolitan Bureau of Public Health.
文摘ALM To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97. andbiological characteristics of the target clones selected by in vivo screening were studied.``RESULTS Two clones with high MHCC97-H and IowMHCC9--L1 metastatic potential were isolated from theparent cell line. Compared with MHCC97-L. MHCC97-H hadsmaller cell size average cell diameter 43 um vs 50 μmand faster in vitro and in vivo growth rate tumor celldoubling time was 34.2 h vs 60.0 h. The main ranges ofchromosomes were 5.5 58 in MHCC97-H and 57 62 inMHCC97-L. Boyden chamber in vitro invasion assay demonstrated that the number of penetrating cells through the artificial basement membrane was 137.5 - 11 .0) cellsfield for MHC_C99--H vs 17.7 - 6.3) field for MHCC97-L.The proportions of cells in GO Gl phase. S phase, and G_ M phase for MHCC97-H MHCC97-L were 0.56 6.65.0.28 0.25 and 0.l6 0.10, respectively, as measured by flow cytometry. The serum AFP levels in nude mice 5 wk after orthotopic implantation of tumor tissue were ( 24666 μg. L for MHCC97-H and (91- 66) μg' L 1 for MHCC97L. The pulmonary metastatic rate was 100% (10-10) vs40% 4- 10).``CONCLUSION Two clones of the same genetic background but with different biological behaviors were established, which could be valuable models for investigation on HCC metastasis.
文摘Mapplng of low of slngle-copy sequences on plant chromosomes has proven dirricult because ofvery low frequency or slgnal detectlon. Rlce BAC Ilbrary ls belng used wldely ln rlce genome research due tolts distlnctlve advantages over other llbrary systems. In tkls study, two blotln-Iabeled rice BAC clones closelylinked to a rlce blast reslstance, green Ieaf hopper reslstance and tungro spherlcal virus resistance gene,Pi-5(t),Glh, RTSV, were in situ hybrldlred to rlce ckromosomes. They were located on the long arm andshort arm of ckromosome 4 with FL value of 40% and 100% respectively-The rrequency of signal detectionreacked 46. 8% and 59- 2%- The slgnal location were conslstent wltk the selectlve marker on rice saturatedm0Iecular map. The results demonstrated the advautages to Iocate BAC cIones to ckromosomes by in sho hybrldization and will racilitate tke rlce low of slngle-copy gene Iocation by using the BAC library.
基金supported by the State Key Basic Research Project(973 project)of China(Grant No.2007CB116308)Planned Projects for Postdoctoral Research Funds of Jiangsu Province,China(Grant No.5910602)Postdoctoral Funds of Jiangsu Academy of Agricultural Sciences,China(Grant No.6510501)
文摘The ultrastructure of porcine kidney(PK)-15 cells was examined after lipofectamine-aided transfection of the molecular clone of the P1 agent.PK-15 cells transfected with the tandem dimer of the P1molecular DNA clone had numbers of intracytoplasmic inclusions,and a few cells had intranuclear inclusions.Intracytoplasmic inclusions were round to oval and 0.1-0.3μm in diameter,and intranuclear inclusions,which were more electron dense,were of two general types:the first were round and small(0.1μm approximately)and the second were hexagonal and larger(0.4-0.8μm in diameter).Cells transfected with the tandem dimer of the P1 molecular DNA clone tested positive for P1 DNA at passage 5.This is the first report that the P1 molecular clone has infectivity in vitro and it will provide fundamental materials for further study of the biological characterization of P1.
基金supported by a grant of Directorate of General Higher Education,Ministry of Education and Culture of Indonesia for the"BPPDN"scholarship
文摘Objective:To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone.Methods:Green tea GMB-4 clones were extracted with distilled water at 90C.Samples were eluted into the column with 10%ethanol.Subsequently,the column was eluted with95%ethanol and evaporated separately.Green tea extract was identified by thin layer chromatography.Catechins were separated by the stationary phase in column chromatography using polyamide with 10%ethanol eluent and 95%ethanol.The results of isolations were analyzed by high performance liquid chromatographic(HPLC)and LCMS/MS.Analysis of catechins by HPLC was done by external standard.Results:Fraction from 10%ethanol showed that four major peaks at retention time of1.663,2.367,2.950 and 4.890,indicated the presence of four catechins components including catechin,epicatechins,gallocatechin and epigallocatechin.Whereas,fraction from 95%ethanol showed two main peaks at retention time of 5.167 and 9.82,which indicated the presence of epigallocatechin gallate(EGCG)and epicatechin gallate(ECG).EGCG(m/z 459),epigallocatechin(m/z 307),ECG(m/z 443),and epicatechin(m/z 291)were isolated and separated successfully using HPLC and LC-MS/MS.Conclusions:The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG.Four major catechins were separated and identified by LC-MS/MS,such as EGCG,epigallocatechin,ECG and epicatechin.The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.
基金supported by the National Natural Science Foundation(C36970359).
文摘Bovine embryonic stem cell would be invaluable for researching the aspect of animal cloning, production transgenic animal and discussion of gene function in vitro. With the object of establishing an effective culture system for isolation and clone of bovine pluripotent stem cell, we cultured bovine embryos and mouse embryos including morula blastula and hatached blastula and obtained animal ICM on Primary marine embryonic fibroblast (Primary murine embryonic fibroblast, PMEF) feeder layer with tissue medium(DMEM supplemented with 15ml/100ml NBS ,0.1μmol/L Na2SeO3, 0. 1mmol/L β-mercaptoethanol, 1 000ng/ml LIF,10 ng/ml IGF, 1mmol/L necessary amino acid and 1mmol/L L-glutamine), then, we obtained mouse ICM and bovine ICM. Moreover, we isolated and cloned the 6 passage bovine ES like cells(12 cell lines) and 9 passage marine ES like cells (52 cell lines) deriving from bovine ICM and murine ICM respectively on the feeder layer of PMEF by disaggregating ICM and ES cell clones of bovine and murine into smaller clumps through digesting with 0. 125g/100ml trypsin and 0.02g/100ml EDTA and scattering with a glass needle. The pluripotency of both murine and bovine ES like cells was identified with morphological character, histochemistry identification, karyotype analysis and differentiation of ES cells in vitro or in vivo. This result showed that bovine embryonic stem cell and murine embryonic stem cell had developmental pluripotency.
基金supported by the National Key Research and Development Program of China (Grant No.2016YFD0600404)the Fundamental Research Funds for the Central Universities (Grant No.2572017DA02)。
文摘Growth characteristics have complex inheritance patterns and genotype(G) by environment(E) interaction make predicting tree response to environmental changes difficult.In this study,the growth of seven poplar clones at three different sites was taken as the research focus,and heights and basal diameters were investigated in the second growing season.An ANOVA showed that all main effects,site,clone number and their interactions were highly significant in the overall F-tests.The coefficients of variation and repeatability of different traits ranged from 15.5 to 43.9%and from 0.549 to 0.912,respectively.AMMI(Additive Main Effects and Multiplicative Interaction) analysis results showed that genotype,environment and G × E interaction were significantly highly correlated.The stability analysis indicated that different clones showed different growth traits on different sites,which suggests that elite clones should be selected separately for different sites.Based on the growth traits,under a 10% selection rate,three clones were selected for different sites and the genetic gains of growth traits ranged from 4.7 to 11.2%.The three selected clones could be used to establish plantations in the future in different sites.
基金the “Tenth Five-year Plan”National Key Project in Science and Technology (Grant No. 2002BA515B0303) and the National “863”Project (Grant No. 2002AA241071)
文摘Effects of seven planting densities on the growth and tree form of nine 5-year-old new clones in Populus tomentosa were studied. The plantations, arranged with completely random block design, were located in Wuzhi County, Henan Province. Results indicated that effects of planting density on the diameter at breast height (DBH), individual volume and growing stock increment of all new clones in P. tomentosa were significant at the 1% level of probability, effects of planting density on the tree height increment of new clones B2 and B31 and on the live branches height (LBH) increment of new clones B5 and B30 were significant at the 5% level of probability, while the interaction between planting density and clone was not significant at the 5% level of probability. It was concluded that the degree of differences among new clones within the same planting density was different with different planting densities and traits. For short rotation industrial timber, clones B1, B3, B4, B5, B7, B9, B31 were suitable with the density of 1 0002 500 trees per hectare, while for bigger diameter timber, clones B1, B3, B4, B7, B9, B31 could be used with the planting density of 660833 trees per hectare. Clonal repeatability was also different in different planting densities.
基金Key Project, the Ninth Five-Year Plan of China! 96-008-01-02-06Project of Bio-Engineering Center of China! SSTC 96-C01-05-01
文摘In China, the total annual production of cultured Laminaria japonica reached half million tons in dry weight there few years. The routine sporeling culture technique conducted in the greenhouse took at least three and half months. In such a case, sometimes the sporelings died within a few days due to destructive diseases. In Order to overcome the mentioned problems, a new sporeling culture technique, the clone technique, is developed. The method includes three stead: (1) Gametophyte clone culture. The spores and the gametophytes are cloned in flasks under favorable environments. (2) Sporeling cul ture. Male and female clones are crushed and spread onto a frame to allow the gametophytes to attach to the substrata. The frames are cultured in tanks, and the sporophytes reach 1 cm in length within one and a half months. (3) Outgrowing of the plant. The frames are put in the open sea when seawater temperature decreased to 20℃. After one month, the sporelings are large enough to be transplanted. It is concluded that the clone technique has the following advantages: (1)Large amount of clones can be produced in a short period of time. (2) Clone seeding method makes it free from the biological rhythm, one can seed the plant anytime all the year round. (3) It takes only one and a half months to complete the process of sporeling cultivation in the greenhouse. At present, this technique is used in the breeding of new strains of Laminaria.
文摘Guava (Psidium guajava L.), a tropical fruit, belongs to Myrtaceae family. Leaves and fruits of guava have been reported to have an anti-diarrheal, hypoglycemic, lipid lowering, anti-bacterial in addition to antioxidant activities. The aim of this study was to investigate several guava leaf extract cytotoxic effects on healthy clone 9 liver cells and its hepatoprotective effects on ethanol-induced heap-toxicity. It was discovered that when the clone 9 liver cells were treated with guava (Psidium guajava Linn.) extracts for 24 hours, there was no retardation of growth as well as when ethanol and acetone extracts at low concentrations 100 μg/mL and 50 μg/mL were administered however cytototoxic effects were detected at higher concentrations. Water and hot water extracts in concentrations lower than or equal to 500 μg/mL revealed no cytotoxic effects. Injury induction to healthy clone 9 liver cells using 5% alcohol concentration for 30 minutes revealed the hepatoprotective properties of guava (Psidium guajava Linn.) extracts. This was significant in concentrations of 100 μg/mL or lower for ethanol and all concentrations for hot water extracts. Hot water extracts showed higher hepatoprotective and lower cytotoxic properties than other extracts.
文摘Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microflora distribution;however, here we analyzed the bacterial diversity in colonic mucus from UC patients receiving colectomy surgery and control patients. The diversity of microflora was investigated using a combination of terminal restriction fragment length polymorphism (T-RFLP) and clone library analyses of the 16S rRNA gene sequences. In the T-RFLP analysis, the number of terminal restriction fragments (T-RFs) decreased significantly in UC patients when compared to control samples. Also in the clone library analysis, the number of operational taxonomic units (OTU) and the Shannon diversity index were reduced significantly in UC patients. These molecular analyses reveal an overall dysbiosis in UC patients. No specific pathogen was found, and a strong negative correlation in relative abundance of bacterial populations was observed between the phyla Bacteroidetes and Firmicutes in the UC patients. This is the first report showing a significant correlation between these two phyla, which may be important characteristics in the pathogenesis of UC.
文摘We studied the variability in longitudinal growth strains and wood basic density in five-year old trees from five clones (one tree per clone) of Eucalyptus tereticornis. Mean longitudinal growth strain in clones ranged from 466 to 876 μm. There was a significant difference between clones in growth strains and wood basic density. Clone 10 exhibited maximum growth strains and basic density, whereas clone 3 and clone 7 exhibited minimum growth strains and basic density, respectively. Within a tree, the growth strain variation with tree height was high but statistically insignificant while within tree variation in basic density was very small. There was no specific trend in variation in either strain or density within a tree. There was 5% 200% difference in growth strain on opposite sides of the logs. However two strains showed a strong positive correlation. There was a moderate positive association of wood basic density and mean growth strains in logs. The variation around the periphery emphasize the need to measure strain more than one, preferably on opposite sides at the same height, on a tree to know the mean strain level for the purpose of selection of clones.
