The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely ...The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33~N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 pg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii (4.61-15.04 ~tg C/L vs. 0.34-0.89 pg C/L). Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 ~tg C/(L.d) in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence ofN. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.展开更多
An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results s...An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.展开更多
Various busbar configurations were built and modeled by the custom code based on the commercial package ANSYS for the 500 kA aluminum electrolysis cell.The configuration parameters,such as side riser entry ratio,numbe...Various busbar configurations were built and modeled by the custom code based on the commercial package ANSYS for the 500 kA aluminum electrolysis cell.The configuration parameters,such as side riser entry ratio,number of cathode bars connected to each riser,vertical location of side cathode busbar and short side cathode busbar,distance between rows of cells in potline,the number of neighboring cells,ratio of compensation busbar carried passing under cell and its horizontal location under cell along with large magnetohydrodynamic(MHD) computation based on the custom evaluation function were simulated and discussed.The results show that a cell with riser entry ratio of 11:9:8:9:11 and cathode busbar located at the level of aluminum solution,50% upstream cathode current passing under cell for magnetic field compensation,the distance between rows of 50 m is more stable.展开更多
AIM: To investigate the biological function of HBcAg in pathogenesis of HBV replication in peripheral blood mononuclear cells (PBMCs).METHODS: HBcAg region was amplified by polymerase chain reaction (PCR) and HB...AIM: To investigate the biological function of HBcAg in pathogenesis of HBV replication in peripheral blood mononuclear cells (PBMCs).METHODS: HBcAg region was amplified by polymerase chain reaction (PCR) and HBV HBcAg bait plasmid pGBKT7-HBcAg was constructed by routine molecular biological methods. Then the recombinant plasmid DNA was transformed into yeast AH109. After the HBV core protein was expressed in AH109 yeast strains (Western blot analysis), yeast-two hybrid screening was performed by mating AH109 with Y187 containing leukocyte cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His- Ade) (QDO) and synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) (TDO). The second screening was performed with the LacZ report gene ( yeast cells were grown in QDO medium containing X-a-gal). The interaction between HBV core protein and the protein obtained from positive colonies was further confirmed by repeating yeast-two hybrid. After plasmid DNA was extracted from blue colonies and sequenced, the results were analyzed by bioinformatic methods.RESULTS: Eighteen colonies were obtained and sequenced, including hypermethylated in cancer 2 (3 colones), eukaryotic translation elongation factor 2 (2 colones), acetyl-coenzyme A synthetase 3 (1 colone), DNA polymerase gamma (1 colone), putative translation initiation factor (1 colone), chemokine (C-C motif) receptor 5 (1 colone), mitochondrial ribosomal protein L41 (1 colone), kyot binding protein genes (1 colone), RanBPM (1 colone), HBeAg-binding protein 3 (1 colone), programmed cell death 2 (1 colone). Four new genes with unknown function were identified.CONCLUSION: Successful cloning of genes of HBV core protein interacting proteins in leukocytes may provide some new clues for studying the biological functions of HBV core protein.展开更多
Objective:To search for risk factors that affect mother-to-infant transmission of hepatitis B virus(HBV). Methods:To obtain studies eligible for meta-analysis, China biological medicine discs and MEDLINE citations...Objective:To search for risk factors that affect mother-to-infant transmission of hepatitis B virus(HBV). Methods:To obtain studies eligible for meta-analysis, China biological medicine discs and MEDLINE citations were surveyed. Mother HBV DNA or HBeAg positivity,neonate HBeAg positivity, mode of delivery, threatened abortion and threatened premature labor were processed with meta analysis. Criteria for selection of published studies for meta analysis were based on principle by Abdolmaleky HM. Odds ratio (OR) was calculated and summarized by fixed effect model or random-effects model using RevMan software. The heterogeneity of the group of ORs was assessed using an X^2 test. The significance of the pooled OR was determined by the u-test. The strength of association was assessed using the OR. An OR〉1. 0 indicated a positive association between the risk factor and neonate HBV infection. Results: After meta analysis of factors concerned, a significant association was found between the positivity of HBeAg in mother and neonate, of HBV DNA in mother peripheral serum, and HBV mother-to-infant transmission, with a pooled OR equal to 19.43 (95% CI=8. 77-43. 06), 36.5 (95% CI= 19.85-67. 11), and 36.5 (95 % CI= 19.85-67.11 ) respectively. Mode of delivery, threatened abortion and threatened premature labor proved not to be of risk factors on the mother-to-infant transmission of HBV. Conclusion: Mother HBV DNA or HBeAg positivity and neonate HBeAg positivity were proved to be of risk factors affecting the transmission of HBV from mother to fetal.展开更多
In light of the problems of low-quality and low degree of comprehensive utilization of Guangdong muscovite-type kaolin, the reasons affecting the quality of kaolin were found to be a small amount of maroon powdery goe...In light of the problems of low-quality and low degree of comprehensive utilization of Guangdong muscovite-type kaolin, the reasons affecting the quality of kaolin were found to be a small amount of maroon powdery goethite adhering to the surface of kaolin and minor muscovite affecting the firing whiteness of products. The ores were dealt with by using the new combined process of attritioning-classifieation-bleaching and flotation. The separation of kaolin from muscovite, quartz and feldspar can come true through the new process. The high-quality kaolin with the firing whiteness of 91% can be obtained, and the muscovite is comprehensively recovered by adopting the key technology of flotation. The content of high-purity muscovite produced is over 99%. The muscovite discarded by original process can be comprehensively recovered.展开更多
[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase (SAMS) in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was ...[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase (SAMS) in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was amplified by PCR and inserted into the secreted expression vector pPIC9K to get recombinant plasmid. The recombinant plasmid pPIC9K-sarr~ was integrated into Pichia pastoris GSl15 genome by electroporation and induced by methanol. The activity of the recombinant enzyme was measured using high-pedormance liquid chroma- tography (HPLC) by determining the production of S-adenosy-L-methionine (SAM) with the enzyme secreted. [ ResultJ The molecular weight of the expression protein identified by SDS-PAGE was about 50 kD, being larger than the theoretical molecular mass of SAMS, which might be due to the glycosytation in the process of secretion. Methanol-induction as well as preliminary purification could enhance the enzyme activity, espe- cially the latter, after which the specific activity of SAMS was improved to 61.48 U/rng. [Conclusion] SAMS with biological activity was secreted successfully in Pichia pastoris GSl15 for the first time. And it is the start for the genetic engineering strains to open up prospects for industrial production.展开更多
A massive bloom of the giant jellyfi sh Nemopilema nomurai occurred in waters off Qinhuangdao,a port city in Hebei Province,in July 2013.However,jellyfi sh larvae were not found in this location during the previous wi...A massive bloom of the giant jellyfi sh Nemopilema nomurai occurred in waters off Qinhuangdao,a port city in Hebei Province,in July 2013.However,jellyfi sh larvae were not found in this location during the previous winter and spring.To determine the possible origin of the giant jellyfi sh medusa in the Bohai Sea,we developed a backward particle-tracking model and a series of numerical simulations were conducted by using the hydrodynamic,three-dimensional Regional Ocean Modeling System(ROMS)results.The simulated results showed that passive particles,representing jellyfi sh medusae,released in surface waters at diff erent dates during the summer had consistent trajectories.Particles released at the sea surface on August1 and 15 could be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and the new Huanghe(Yellow)River estuary.Particles released on July 1 and 15 could also be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and only to Zhuangxi tide station.However,none of the particles released in the middle and bottom water layers could be traced back to those areas.Based on the results of the numerical simulations,the distribution characteristics of seafl oor sediments,and observational data for giant jellyfi sh in the region,we suggest that waters between Feiyan Shoal and the new Huanghe River estuary are the likely origin of giant jellyfi sh observed near Qinhuangdao in summer.展开更多
This paper is on a distribution question of Ⅰ type in the combinatorics (see: 'Ke Zhao, Wei WanDi, combinatorial theory, science press, 1981. '). Suppose n distrinct balls, m distinct boxes. The capacity set...This paper is on a distribution question of Ⅰ type in the combinatorics (see: 'Ke Zhao, Wei WanDi, combinatorial theory, science press, 1981. '). Suppose n distrinct balls, m distinct boxes. The capacity set of every box is Now,place the n balls into the m boxes. Thenumber of distinct placed ways is expressed by , and simply by And it is called the distribution number.Main result is:Theorem The exponential generating function of sequence isThus .there is the recurrence relationhere (integer set).展开更多
AIM:To investigate the effects of Saccharomyces boulardii(S.boulardii) in an experimental rat model of trinitrobenzene sulfonic acid(TNBS)-induced colitis.METHODS:Thirty-two Wistar albino female rats were categorized ...AIM:To investigate the effects of Saccharomyces boulardii(S.boulardii) in an experimental rat model of trinitrobenzene sulfonic acid(TNBS)-induced colitis.METHODS:Thirty-two Wistar albino female rats were categorized into five groups.On the first day of the study,50 mg TNBS was administered via a rectal catheter in order to induce colitis in all rats,except those in the control group.For 14 d,the rats were fed a standard diet,without the administration of any additional supplements to either the control or TNBS groups,in addition to 1 mg/kg per day S.boulardii to the S.boulardii group,1 mg/kg per day methyl prednisolone(MP) to the MP group.The animals in the S.boulardii + MP group were coadministered these doses of S.boulardii and MP.During the study,weight loss,stool consistency,and the presence of obvious blood in the stool were evaluated,and the disease activity index(DAI) for colitis was recorded.The intestines were examined and colitis was macro-and microscopically scored.The serum and tissue levels of tumor necrosis factor-α(TNF-α) and nitric oxide(NO) were determined,and fungemia was evaluated in the blood samples.RESULTS:The mean DAI scores for the MP and S.boulardii + MP groups was significantly lower than the TNBS group(3.69 ± 0.61 vs 4.46 ± 0.34,P = 0.018 and 3.77 ± 0.73 vs 4.46 ± 0.34,P = 0.025,respectively).While no significant differences between the TNBS and the S.boulardii or MP groups could be determined in terms of serum NO levels,the level of serum NO in the S.boulardii + MP group was significantly higher than in the TNBS and S.boulardii groups(8.12 ± 4.25 μmol/L vs 3.18 ± 1.19 μmol/L,P = 0.013;8.12 ± 4.25 μmol/L vs 3.47 ± 1.66 μmol/L,P = 0.012,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were significantly lower than the TNBS group(16.62 ± 2.27 μmol/L vs 29.72 ± 6.10 μmol/L,P = 0.002;14.66 ± 5.18 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.003;11.95 ± 2.34 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.002,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were similar.The mean serum and tissue TNF-α levels were determined to be 12.97 ± 18.90 pg/mL and 21.75 ± 15.04 pg/mL in the control group,18.25 ± 15.44 pg/mL and 25.27 ± 11.95 pg/mL in the TNBS group,20.59 ± 16.15 pg/mL and 24.39 ± 13.06 pg/mL in the S.boulardii group,9.05 ± 5.13 pg/mL and 24.46 ± 10.85 pg/mL in the MP group,and 13.95 ± 10.17 pg/mL and 24.26 ± 10.37 pg/mL in the S.boulardii + MP group.Significant differences in terms of the levels of serum and tissue TNF-α and the macroscopic and microscopic scores were not found between the groups.S.boulardii fungemia was not observed in any of the rats.However,Candida fungemia was detected in one rat(14%) in the TNBS group,two rats(28%) in the S.boulardii group,three rats(50%) in the MP group,and three rats(42%) in S.boulardii + MP group.CONCLUSION:S.boulardii does not demonstrate considerable effects on the DAI,pathological scores,or cytokine levels but does decrease the tissue NO levels.展开更多
Sherwood Anderson's Winesburg, Ohio (1919) has been the focus of numerous studies from a number of standpoints. This paper explores a short story "Mother" (1919) from Winesburg, Ohio and studies it from an eval...Sherwood Anderson's Winesburg, Ohio (1919) has been the focus of numerous studies from a number of standpoints. This paper explores a short story "Mother" (1919) from Winesburg, Ohio and studies it from an evaluation-based perspective embracing the analysis of the artistic language and the style of the author's narration. The main focus of the study is concentrated on the genre-related issues as well as on the determining the reason why Anderson avoids the development of the given text and transforming it into the regime of a more large-scale prose. As it turns out from the analysis, Anderson elaborates a specific style of narration and creates the form that can be characterized as the mode of "epic sketch". Anderson favors to use much smaller meter and scope, and that choice serves the writer's purpose to describe the psychological portrait of one of the characters of the above-mentioned short story.展开更多
AIM: Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied. ME...AIM: Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied. METHODS: Genomic DNA was isolated and metaphases were prepared, respectively from mouse oocytes cocultured with pBR322-HBV DNA plasmids. PCR, Southern blot, dot hybridization and fluorescence in situ hybridization (FISH) were performed to explore the existence and integration of HBV DNA in oocytes.RESULTS: PCR detected positive bands in the tested samples, and then Southern blot revealed clear hybridization signals in PCR products. Final washing solutions were collected for dot hybridization and no signal for HBV DNA was observed, which excluded the possibility that contamination of washing solutions gave rise to positive results of PCR and Southern blot. FISH demonstrated that 36 of 1 000 metaphases presented positive signals. CONCLUSION: HBV DNA sequences are able to pass through the zona and oolemma to enter into oocytes and tointegrate into their chromosomes. HBV DNA sequences might be brought into embryo via oocytes as vectors when they are fertilized with normal spermatozoa.展开更多
Methylotrophic yeast has been used as a cost-effective and valuable host for expression of recombinant protein due to its unique methanol utilisation pathway. It has an AOX (alcohol oxidase) protein which has been c...Methylotrophic yeast has been used as a cost-effective and valuable host for expression of recombinant protein due to its unique methanol utilisation pathway. It has an AOX (alcohol oxidase) protein which has been characterised to be a strong and tightly methanol-inducible dependent promoter. Metabolomics is the systematic study and inclusive analysis of small molecules called metabolites in a biological system. Metabolomics plays an important part in connecting the phenotype and genotype gap because it magnifies the modifications in the proteome and provides a better phenotype representation of an organism. This quantitative study has provided a new perception on the metabolic burden derived from the overexpression of recombinant protein in methylotrophic yeast. In this review, we discuss the fundamental aspect of metabolomics in methylotrophic yeast followed by their latest developments.展开更多
Artificially induced tetraploid Pacific oyster, Crassostrea gigas Thunberg, produces more aneuploid gametes than nor- mal diploid one, although they showed a comparable fecundity to diploidy. The meiotic chromosome co...Artificially induced tetraploid Pacific oyster, Crassostrea gigas Thunberg, produces more aneuploid gametes than nor- mal diploid one, although they showed a comparable fecundity to diploidy. The meiotic chromosome configuration of 3 tetraploid and 1 tetraploid/triploid mosaic males were analyzed through direct chromosome observation. A majority of metaphase I spermato- cytes contained both bivalents and quadrivalents. The chromosome configuration of these males was characterized by preferential formation of bivalents to quadrivalents. Bivalents appeared in all spermatocytes and consisted of 86% of all chromosome aggregates. In comparison, quadrivalents occurred in 91% spermatocytes and consisted of only 12.6% of all chromosome aggregates. The mean bivalent frequency per spermatocyte varied between 14.4 and 17.2; while that of quadrivalents varied between 2.2 and 2.7. Most quadrivalents were tandemly chained (58%) or circled (39%). The total number of chromosome aggregates per spermatocyte ranged from 13 to 20 with an average of 17.6; while 18 (16 bivalents and 2 quadrivalents) was the most frequent. Univalents and trivalents appeared in very low frequency. Aneuploid (hypotetraploid) spermatocytes were observed in a low frequency. The chromosome con- figuration of in the mosaic individual was similar to that of tetraploid individuals. The percentage of triploid spermatocytes (2%) of the mosaic individual was significantly lower (2"2 =30, P〈 0.01) than that of triploid cells (46%) in its somatic tissue.展开更多
AIM: To investigate the biological function of F protein by yeast two-hybrid system. METHODS: We constructed F protein bait plasmid by cloning the gene of F protein into pGBKT7, then recombinant plasmid DNA was tran...AIM: To investigate the biological function of F protein by yeast two-hybrid system. METHODS: We constructed F protein bait plasmid by cloning the gene of F protein into pGBKT7, then recombinant plasmid DNA was transformed into yeast AH109 (a type). The transformed yeast AH109 was mated with yeast Y187 (α type) containing liver cDNA library plasmid in 2×YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-HisAde) containing X-α-gal for selection and screening. After extracting and sequencing plasmids from positive (blue) colonies, we underwent sequence analysis by bioinformatics. RESULTS: Thirty-six colonies were selected and sequenced. Among them, 11 colonies were zymogen granule protein, 5 colonies were zinc finger protein, 4 colonies were zinc-α-2-glycoprotein, 1 colony was sialyltransferase, 1 colony was complement control protein factor I, 1 colony was vitronectin, and 2 colonies were new genes with unknown function. CONCLUSION: The yeast two-hybrid system is an effective method for identifying hepatocyte proteins interacting with F protein of hepatitis C virus. F protein may bind to different proteins. 2005 The WJG Press and Elsevier Inc. All rights reserved展开更多
The Zhuxi W(Cu)skarn deposit,the world’s largest tungsten deposit is newly discovered in Jingdezhen city,northeastern Jiangxi province,China.It mainly occurs near the contact zone between the Yanshanian granites and ...The Zhuxi W(Cu)skarn deposit,the world’s largest tungsten deposit is newly discovered in Jingdezhen city,northeastern Jiangxi province,China.It mainly occurs near the contact zone between the Yanshanian granites and the Late Paleozoic carbonate rocks.Three types of mineralization including skarn type,altered granite type and quartz vein veinlet type orebodies have been observed.In this study,the 40Ar 39Ar age of hydrothermal muscovite coexisting with copper mineralization in the altered granite type orebody formed near the unconformity interface is determined by step-heating technology using CO2 laser.The plateau age,isochron age,and inverse isochron age of muscovite are(147.39±0.94)Ma,(147.2±1.5)Ma,and(147.1±1.5)Ma,respectively.These ages are almost identical to the ages of ore-related granite and other mineralization types in the Zhuxi W(Cu)deposit,indicating that the Cu mineralizations occurred at the shallow depth and near the unconformity interface are contemporaneous during the Late Jurassic.This further suggested that the acompanied W and Cu mineralization in the Zhuxi W(Cu)deposit which may be controlled by the magma source is enriched in both W and Cu.展开更多
The alternative productions, increasingly importance, are based on the rational utilization of the resources, on agreement with the environment and the use of autochthonous breeds that many cases are found in danger o...The alternative productions, increasingly importance, are based on the rational utilization of the resources, on agreement with the environment and the use of autochthonous breeds that many cases are found in danger of disappearance, due to the tact that their suckling is not economically profitable. A way of predicting and knowing the growth of the animals is using mathematical models. This work presented the results of the estimate of the growth according to the Gompertz-Laird model of males of the atttochthonous breed Serrana Soriana and Charolais. The weight to the birth of the breed calfs Charolais (45.14 kg), was superior to those of Serrana Soriana (40.13 kg), and presented a greater relative growth (9.9%) before the inflection point of the growth curve: furthermore it ~as also superior to the maximum decline relative after this point (6%), Serrana Soriana reached 7 days after the maximum growth point but with a smaller weight (315.05 kg vs 384.76 kg). It was calculated a weight to the maturity of 1 ,(176.91) kg for Charolais and 856.40 kg for Serrana Soriana.展开更多
基金Supported by the National Basic Research Program of China(973 Program)(No.2011CB403604)
文摘The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33~N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 pg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii (4.61-15.04 ~tg C/L vs. 0.34-0.89 pg C/L). Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 ~tg C/(L.d) in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence ofN. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.
文摘An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.
基金Project(20010533009) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘Various busbar configurations were built and modeled by the custom code based on the commercial package ANSYS for the 500 kA aluminum electrolysis cell.The configuration parameters,such as side riser entry ratio,number of cathode bars connected to each riser,vertical location of side cathode busbar and short side cathode busbar,distance between rows of cells in potline,the number of neighboring cells,ratio of compensation busbar carried passing under cell and its horizontal location under cell along with large magnetohydrodynamic(MHD) computation based on the custom evaluation function were simulated and discussed.The results show that a cell with riser entry ratio of 11:9:8:9:11 and cathode busbar located at the level of aluminum solution,50% upstream cathode current passing under cell for magnetic field compensation,the distance between rows of 50 m is more stable.
基金Supported by the National Natural Science Foundation of China,No.30471532
文摘AIM: To investigate the biological function of HBcAg in pathogenesis of HBV replication in peripheral blood mononuclear cells (PBMCs).METHODS: HBcAg region was amplified by polymerase chain reaction (PCR) and HBV HBcAg bait plasmid pGBKT7-HBcAg was constructed by routine molecular biological methods. Then the recombinant plasmid DNA was transformed into yeast AH109. After the HBV core protein was expressed in AH109 yeast strains (Western blot analysis), yeast-two hybrid screening was performed by mating AH109 with Y187 containing leukocyte cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His- Ade) (QDO) and synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) (TDO). The second screening was performed with the LacZ report gene ( yeast cells were grown in QDO medium containing X-a-gal). The interaction between HBV core protein and the protein obtained from positive colonies was further confirmed by repeating yeast-two hybrid. After plasmid DNA was extracted from blue colonies and sequenced, the results were analyzed by bioinformatic methods.RESULTS: Eighteen colonies were obtained and sequenced, including hypermethylated in cancer 2 (3 colones), eukaryotic translation elongation factor 2 (2 colones), acetyl-coenzyme A synthetase 3 (1 colone), DNA polymerase gamma (1 colone), putative translation initiation factor (1 colone), chemokine (C-C motif) receptor 5 (1 colone), mitochondrial ribosomal protein L41 (1 colone), kyot binding protein genes (1 colone), RanBPM (1 colone), HBeAg-binding protein 3 (1 colone), programmed cell death 2 (1 colone). Four new genes with unknown function were identified.CONCLUSION: Successful cloning of genes of HBV core protein interacting proteins in leukocytes may provide some new clues for studying the biological functions of HBV core protein.
文摘Objective:To search for risk factors that affect mother-to-infant transmission of hepatitis B virus(HBV). Methods:To obtain studies eligible for meta-analysis, China biological medicine discs and MEDLINE citations were surveyed. Mother HBV DNA or HBeAg positivity,neonate HBeAg positivity, mode of delivery, threatened abortion and threatened premature labor were processed with meta analysis. Criteria for selection of published studies for meta analysis were based on principle by Abdolmaleky HM. Odds ratio (OR) was calculated and summarized by fixed effect model or random-effects model using RevMan software. The heterogeneity of the group of ORs was assessed using an X^2 test. The significance of the pooled OR was determined by the u-test. The strength of association was assessed using the OR. An OR〉1. 0 indicated a positive association between the risk factor and neonate HBV infection. Results: After meta analysis of factors concerned, a significant association was found between the positivity of HBeAg in mother and neonate, of HBV DNA in mother peripheral serum, and HBV mother-to-infant transmission, with a pooled OR equal to 19.43 (95% CI=8. 77-43. 06), 36.5 (95% CI= 19.85-67. 11), and 36.5 (95 % CI= 19.85-67.11 ) respectively. Mode of delivery, threatened abortion and threatened premature labor proved not to be of risk factors on the mother-to-infant transmission of HBV. Conclusion: Mother HBV DNA or HBeAg positivity and neonate HBeAg positivity were proved to be of risk factors affecting the transmission of HBV from mother to fetal.
文摘In light of the problems of low-quality and low degree of comprehensive utilization of Guangdong muscovite-type kaolin, the reasons affecting the quality of kaolin were found to be a small amount of maroon powdery goethite adhering to the surface of kaolin and minor muscovite affecting the firing whiteness of products. The ores were dealt with by using the new combined process of attritioning-classifieation-bleaching and flotation. The separation of kaolin from muscovite, quartz and feldspar can come true through the new process. The high-quality kaolin with the firing whiteness of 91% can be obtained, and the muscovite is comprehensively recovered by adopting the key technology of flotation. The content of high-purity muscovite produced is over 99%. The muscovite discarded by original process can be comprehensively recovered.
文摘[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase (SAMS) in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was amplified by PCR and inserted into the secreted expression vector pPIC9K to get recombinant plasmid. The recombinant plasmid pPIC9K-sarr~ was integrated into Pichia pastoris GSl15 genome by electroporation and induced by methanol. The activity of the recombinant enzyme was measured using high-pedormance liquid chroma- tography (HPLC) by determining the production of S-adenosy-L-methionine (SAM) with the enzyme secreted. [ ResultJ The molecular weight of the expression protein identified by SDS-PAGE was about 50 kD, being larger than the theoretical molecular mass of SAMS, which might be due to the glycosytation in the process of secretion. Methanol-induction as well as preliminary purification could enhance the enzyme activity, espe- cially the latter, after which the specific activity of SAMS was improved to 61.48 U/rng. [Conclusion] SAMS with biological activity was secreted successfully in Pichia pastoris GSl15 for the first time. And it is the start for the genetic engineering strains to open up prospects for industrial production.
基金Supported by the National Special Research Fund for Non-Profi t Marine Sector(No.201005018)the Open Fund of Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences(No.KLOCAW1403)
文摘A massive bloom of the giant jellyfi sh Nemopilema nomurai occurred in waters off Qinhuangdao,a port city in Hebei Province,in July 2013.However,jellyfi sh larvae were not found in this location during the previous winter and spring.To determine the possible origin of the giant jellyfi sh medusa in the Bohai Sea,we developed a backward particle-tracking model and a series of numerical simulations were conducted by using the hydrodynamic,three-dimensional Regional Ocean Modeling System(ROMS)results.The simulated results showed that passive particles,representing jellyfi sh medusae,released in surface waters at diff erent dates during the summer had consistent trajectories.Particles released at the sea surface on August1 and 15 could be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and the new Huanghe(Yellow)River estuary.Particles released on July 1 and 15 could also be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and only to Zhuangxi tide station.However,none of the particles released in the middle and bottom water layers could be traced back to those areas.Based on the results of the numerical simulations,the distribution characteristics of seafl oor sediments,and observational data for giant jellyfi sh in the region,we suggest that waters between Feiyan Shoal and the new Huanghe River estuary are the likely origin of giant jellyfi sh observed near Qinhuangdao in summer.
文摘This paper is on a distribution question of Ⅰ type in the combinatorics (see: 'Ke Zhao, Wei WanDi, combinatorial theory, science press, 1981. '). Suppose n distrinct balls, m distinct boxes. The capacity set of every box is Now,place the n balls into the m boxes. Thenumber of distinct placed ways is expressed by , and simply by And it is called the distribution number.Main result is:Theorem The exponential generating function of sequence isThus .there is the recurrence relationhere (integer set).
文摘AIM:To investigate the effects of Saccharomyces boulardii(S.boulardii) in an experimental rat model of trinitrobenzene sulfonic acid(TNBS)-induced colitis.METHODS:Thirty-two Wistar albino female rats were categorized into five groups.On the first day of the study,50 mg TNBS was administered via a rectal catheter in order to induce colitis in all rats,except those in the control group.For 14 d,the rats were fed a standard diet,without the administration of any additional supplements to either the control or TNBS groups,in addition to 1 mg/kg per day S.boulardii to the S.boulardii group,1 mg/kg per day methyl prednisolone(MP) to the MP group.The animals in the S.boulardii + MP group were coadministered these doses of S.boulardii and MP.During the study,weight loss,stool consistency,and the presence of obvious blood in the stool were evaluated,and the disease activity index(DAI) for colitis was recorded.The intestines were examined and colitis was macro-and microscopically scored.The serum and tissue levels of tumor necrosis factor-α(TNF-α) and nitric oxide(NO) were determined,and fungemia was evaluated in the blood samples.RESULTS:The mean DAI scores for the MP and S.boulardii + MP groups was significantly lower than the TNBS group(3.69 ± 0.61 vs 4.46 ± 0.34,P = 0.018 and 3.77 ± 0.73 vs 4.46 ± 0.34,P = 0.025,respectively).While no significant differences between the TNBS and the S.boulardii or MP groups could be determined in terms of serum NO levels,the level of serum NO in the S.boulardii + MP group was significantly higher than in the TNBS and S.boulardii groups(8.12 ± 4.25 μmol/L vs 3.18 ± 1.19 μmol/L,P = 0.013;8.12 ± 4.25 μmol/L vs 3.47 ± 1.66 μmol/L,P = 0.012,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were significantly lower than the TNBS group(16.62 ± 2.27 μmol/L vs 29.72 ± 6.10 μmol/L,P = 0.002;14.66 ± 5.18 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.003;11.95 ± 2.34 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.002,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were similar.The mean serum and tissue TNF-α levels were determined to be 12.97 ± 18.90 pg/mL and 21.75 ± 15.04 pg/mL in the control group,18.25 ± 15.44 pg/mL and 25.27 ± 11.95 pg/mL in the TNBS group,20.59 ± 16.15 pg/mL and 24.39 ± 13.06 pg/mL in the S.boulardii group,9.05 ± 5.13 pg/mL and 24.46 ± 10.85 pg/mL in the MP group,and 13.95 ± 10.17 pg/mL and 24.26 ± 10.37 pg/mL in the S.boulardii + MP group.Significant differences in terms of the levels of serum and tissue TNF-α and the macroscopic and microscopic scores were not found between the groups.S.boulardii fungemia was not observed in any of the rats.However,Candida fungemia was detected in one rat(14%) in the TNBS group,two rats(28%) in the S.boulardii group,three rats(50%) in the MP group,and three rats(42%) in S.boulardii + MP group.CONCLUSION:S.boulardii does not demonstrate considerable effects on the DAI,pathological scores,or cytokine levels but does decrease the tissue NO levels.
文摘Sherwood Anderson's Winesburg, Ohio (1919) has been the focus of numerous studies from a number of standpoints. This paper explores a short story "Mother" (1919) from Winesburg, Ohio and studies it from an evaluation-based perspective embracing the analysis of the artistic language and the style of the author's narration. The main focus of the study is concentrated on the genre-related issues as well as on the determining the reason why Anderson avoids the development of the given text and transforming it into the regime of a more large-scale prose. As it turns out from the analysis, Anderson elaborates a specific style of narration and creates the form that can be characterized as the mode of "epic sketch". Anderson favors to use much smaller meter and scope, and that choice serves the writer's purpose to describe the psychological portrait of one of the characters of the above-mentioned short story.
基金Supported by the National Natural Science Foundation of China,No. 39970374
文摘AIM: Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied. METHODS: Genomic DNA was isolated and metaphases were prepared, respectively from mouse oocytes cocultured with pBR322-HBV DNA plasmids. PCR, Southern blot, dot hybridization and fluorescence in situ hybridization (FISH) were performed to explore the existence and integration of HBV DNA in oocytes.RESULTS: PCR detected positive bands in the tested samples, and then Southern blot revealed clear hybridization signals in PCR products. Final washing solutions were collected for dot hybridization and no signal for HBV DNA was observed, which excluded the possibility that contamination of washing solutions gave rise to positive results of PCR and Southern blot. FISH demonstrated that 36 of 1 000 metaphases presented positive signals. CONCLUSION: HBV DNA sequences are able to pass through the zona and oolemma to enter into oocytes and tointegrate into their chromosomes. HBV DNA sequences might be brought into embryo via oocytes as vectors when they are fertilized with normal spermatozoa.
文摘Methylotrophic yeast has been used as a cost-effective and valuable host for expression of recombinant protein due to its unique methanol utilisation pathway. It has an AOX (alcohol oxidase) protein which has been characterised to be a strong and tightly methanol-inducible dependent promoter. Metabolomics is the systematic study and inclusive analysis of small molecules called metabolites in a biological system. Metabolomics plays an important part in connecting the phenotype and genotype gap because it magnifies the modifications in the proteome and provides a better phenotype representation of an organism. This quantitative study has provided a new perception on the metabolic burden derived from the overexpression of recombinant protein in methylotrophic yeast. In this review, we discuss the fundamental aspect of metabolomics in methylotrophic yeast followed by their latest developments.
文摘Artificially induced tetraploid Pacific oyster, Crassostrea gigas Thunberg, produces more aneuploid gametes than nor- mal diploid one, although they showed a comparable fecundity to diploidy. The meiotic chromosome configuration of 3 tetraploid and 1 tetraploid/triploid mosaic males were analyzed through direct chromosome observation. A majority of metaphase I spermato- cytes contained both bivalents and quadrivalents. The chromosome configuration of these males was characterized by preferential formation of bivalents to quadrivalents. Bivalents appeared in all spermatocytes and consisted of 86% of all chromosome aggregates. In comparison, quadrivalents occurred in 91% spermatocytes and consisted of only 12.6% of all chromosome aggregates. The mean bivalent frequency per spermatocyte varied between 14.4 and 17.2; while that of quadrivalents varied between 2.2 and 2.7. Most quadrivalents were tandemly chained (58%) or circled (39%). The total number of chromosome aggregates per spermatocyte ranged from 13 to 20 with an average of 17.6; while 18 (16 bivalents and 2 quadrivalents) was the most frequent. Univalents and trivalents appeared in very low frequency. Aneuploid (hypotetraploid) spermatocytes were observed in a low frequency. The chromosome con- figuration of in the mosaic individual was similar to that of tetraploid individuals. The percentage of triploid spermatocytes (2%) of the mosaic individual was significantly lower (2"2 =30, P〈 0.01) than that of triploid cells (46%) in its somatic tissue.
基金Supported by the National Natural Science Foundation of China, Nos. C03011402 and C30070690 and the Research and Technique Foundation of PLA during the 9~(th)-Five year plan period, No. 98D063 and the Launching Foundation for Student Studying Abroad of PLA, No. 98H038 and the Youth Research and Technique Foundation of PLA during the 10~(th)-Five Year Plan Period, No. 01Q138 and the Research and Technique Foundation of PLA during the 10~(th)-Five Year Plan Period, No. 01MB135
文摘AIM: To investigate the biological function of F protein by yeast two-hybrid system. METHODS: We constructed F protein bait plasmid by cloning the gene of F protein into pGBKT7, then recombinant plasmid DNA was transformed into yeast AH109 (a type). The transformed yeast AH109 was mated with yeast Y187 (α type) containing liver cDNA library plasmid in 2×YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-HisAde) containing X-α-gal for selection and screening. After extracting and sequencing plasmids from positive (blue) colonies, we underwent sequence analysis by bioinformatics. RESULTS: Thirty-six colonies were selected and sequenced. Among them, 11 colonies were zymogen granule protein, 5 colonies were zinc finger protein, 4 colonies were zinc-α-2-glycoprotein, 1 colony was sialyltransferase, 1 colony was complement control protein factor I, 1 colony was vitronectin, and 2 colonies were new genes with unknown function. CONCLUSION: The yeast two-hybrid system is an effective method for identifying hepatocyte proteins interacting with F protein of hepatitis C virus. F protein may bind to different proteins. 2005 The WJG Press and Elsevier Inc. All rights reserved
基金Project(41873059)supported by the National Natural Science Foundation of ChinaProject(JGMEDB [2017]78)supported by the Jiangxi Geological and Mineral Exploration and Development Bureau Foundation,China+2 种基金Project(2011BAB04B02)supported by the National Science and Technology Support Plan Project,ChinaProject(201411035)supported by the Welfare Research Program of Ministry of Land and Resources,ChinaProject(20150013)supported by Jiangxi Provincial Geological Exploration Fund Management Center,China
文摘The Zhuxi W(Cu)skarn deposit,the world’s largest tungsten deposit is newly discovered in Jingdezhen city,northeastern Jiangxi province,China.It mainly occurs near the contact zone between the Yanshanian granites and the Late Paleozoic carbonate rocks.Three types of mineralization including skarn type,altered granite type and quartz vein veinlet type orebodies have been observed.In this study,the 40Ar 39Ar age of hydrothermal muscovite coexisting with copper mineralization in the altered granite type orebody formed near the unconformity interface is determined by step-heating technology using CO2 laser.The plateau age,isochron age,and inverse isochron age of muscovite are(147.39±0.94)Ma,(147.2±1.5)Ma,and(147.1±1.5)Ma,respectively.These ages are almost identical to the ages of ore-related granite and other mineralization types in the Zhuxi W(Cu)deposit,indicating that the Cu mineralizations occurred at the shallow depth and near the unconformity interface are contemporaneous during the Late Jurassic.This further suggested that the acompanied W and Cu mineralization in the Zhuxi W(Cu)deposit which may be controlled by the magma source is enriched in both W and Cu.
文摘The alternative productions, increasingly importance, are based on the rational utilization of the resources, on agreement with the environment and the use of autochthonous breeds that many cases are found in danger of disappearance, due to the tact that their suckling is not economically profitable. A way of predicting and knowing the growth of the animals is using mathematical models. This work presented the results of the estimate of the growth according to the Gompertz-Laird model of males of the atttochthonous breed Serrana Soriana and Charolais. The weight to the birth of the breed calfs Charolais (45.14 kg), was superior to those of Serrana Soriana (40.13 kg), and presented a greater relative growth (9.9%) before the inflection point of the growth curve: furthermore it ~as also superior to the maximum decline relative after this point (6%), Serrana Soriana reached 7 days after the maximum growth point but with a smaller weight (315.05 kg vs 384.76 kg). It was calculated a weight to the maturity of 1 ,(176.91) kg for Charolais and 856.40 kg for Serrana Soriana.