899 resultados para SIMULTANEOUS LOCALIZATION
Resumo:
Zhikong scallop Chlamys farreri(Jones et Preston) is an economically important species in China. Understanding its immune system would be of great help in controlling diseases. In the present study, an important immunity-related gene, the Lipopolysaccharide and Beta-1,3-glucan Binding Protein (LGBP) gene, was located on C. farreri chromosomes by mapping several lgbp-containing BAC clones through fluorescence in situ hybridization (FISH). Through the localization of various BAC clones, it was shown that only one locus of this gene existed in the genome of C. farreri, and that this was located on the long arm of a pair of homologous chromosomes. Molecular markers, consisting of eight single nucleotide polymorphism (SNPs) markers and one insertion-deletion (indel), were developed from the LGBP gene. Indel marker testing in an F1 family revealed slightly distorted segregation (p = 0.0472). These markers can be used to map the LGBP gene to the linkage map and assign the linkage group to the corresponding chromosome. Segregation distortion of the indel marker indicated genes with deleterious alleles might exist in the surrounding region of the LGBP gene.
Resumo:
Transglutaminase can catalyze the cross-linking reaction between soluble clotting protein molecules from the plasma for prevention of excess blood loss from a wound and obstructing micro-organisms from invading the wound in crustaceans. A novel transglutaminase (FcTG) gene was cloned from hemocytes of Chinese shrimp Fenneropenaeus chinensis by 3' and 5' rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA consists of 2972 bp, encoding 757 amino acids with a calculated molecular mass of 84.96 kDa and a theoretical isoelectric point of 5.61. FcTG contains a typical transglutaminase-like homologue (TGc domain: E-value = 1.94e-38). Three catalytic sites (Cys-324, His-391 and Asp-414) are present in this domain. The deduced amino acid sequence of FcTG showed high identity with black tiger shrimp TG, kuruma shrimp TG and crayfish TG. Transcripts of FcTG mRNA were mainly detected in gill, lymphoid organ and hemocytes by RT-PCR. RNA in situ hybridization further confirmed that FcTG was constitutively expressed in hemocytes both in the circulatory system and lymphoid organ. The variation of mRNA transcription level in hemocytes and lymphoid organ following injection of killed bacteria or infection with white spot syndrome virus (WSSV) was quantified by RT-PCR. The up-regulated expression of FcTG in shrimp lymphoid organ following injection of bacteria indicates that it is inducible and might be associated with bacterial challenge. (c) 2006 Elsevier Ltd. All rights reserved.
Resumo:
Bacterial flagellin is known to induce potent immune response in vertebrate systems via the toll-like receptor (TLR) 5. As a result, flagellin has been studied extensively as a vaccine adjuvant. In a previous study, we examined the vaccine and adjuvant potentials of the flagellin (FliC) of the fish pathogen Edwardsiella tarda. We found that E. tarda FliC induced low protective immunity by itself but could function as a molecular adjuvant and potentiate the specific immune response induced by the E. tarda antigen Eta6. Since FliC is a large protein and organized into distinct structural domains, we wondered whether the immunostimulating effect observed with the full-length protein could be localized to a certain region. To investigate this question, we in the present study dissected the FliC protein into several segments according to its structural features: (i) N163, which consists of the conserved N-terminal 163 residues of FliC; (ii) M160, which consists of the variable middle 160 residues; (iii) C94, which consists of the conserved C-terminal 94 residues; (iv) NC257, which is an artificial fusion of N163 and C94. To examine the adjuvanticity of the FliC fragments, DNA vaccine plasmids expressing FliC fragments in fusion with Eta6 were constructed and used to immunize Japanese flounder. The results showed that N163 produced the best adjuvant effect, which, in respect to improvement in the relative percent survival of the vaccinated fish, was comparable to that of the full-length FliC. None of the other FliC fragments exhibited apparent immunopotentiating effect. Further analysis showed that N163 enhanced the production of serum specific antibodies and, like full-length FliC, significantly upregulated the expression of the genes that are possibly involved in innate and adaptive immunity. These results indicate that N163 is the immunodominant region of FliC and suggest that E. tarda FliC may induce immune responses in Japanese flounder via mechanisms alternative to that involving TLR5. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
A full length amphioxus cDNA, encoding a novel phosducin-like protein (Amphi-PhLP), was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open reading frame (ORF) of 241 amino acids, with a predicted molecular mass of approximately 28 kDa. In situ hybridization histochemistry revealed a tissue-specific expression pattern of Amphi-PhLP with the high levels in the ovary, and at a lower level in the hind gut and testis, hepatic caecum, gill, endostyle, and epipharyngeal groove, while it was absent in the muscle, neural tube and notochord. In the Chinese Hamster Ovary (CHO) cells transfected with the expression plasmid pEGFP-N1/Amphi-PhLP, the fusion protein was targeted in the cytoplasm of CHO cells, suggesting that Amphi-PhLP is a cytosolic protein. This work may provide a framework for further understanding of the physiological function of Amphi-PhLP in B. belcheri.
Resumo:
The progress in genome sequencing has led to an increasing submission of uncharacterized hypothetical genes with the domain of unknown function, DUF985, in GenBank, and none of these genes is related to a known protein. We therefore underwent an experimental study to identify the function of a DUF985 domain-containing hypothetical gene BbDUF985 (GenBank Accession No. AY273818) isolated from amphioxus Branchiostoma belcheri (B. belcheri). BbDUF985 was successfully expressed in both prokaryotic and eukaryotic systems, and its recombinant proteins expressed in both systems definitely exhibited an activity of phosphoglucose isomerase (PGI). Both tissue-section in situ hybridization and immunohistochemistry demonstrated that BbDUF985 was expressed in a tissue-specific manner, with most abundant levels in the hepatic caecum and ovary. In CHO cells transfected with the expression plasmid pEGFP-N1/BbDUF985, the fusion protein was targeted in the cytoplasm of CHO cells, suggesting that BbDUF985 is a cytosolic protein. In contrast, Western blotting indicated that BbDUF985 was also present in amphioxus humoral fluids, suggesting that it exists as a secreted protein as well. Our study provided a framework for further understanding the biochemical properties and physiological function of DUF985-containing hypothetical proteins in other species. (c) 2008 Elsevier Inc. All rights reserved.
Resumo:
According to the specific property of respective phases in copper ore, optimal extracting condition for, tour phases of copper with five infusion was examined. After a series of experiments, for example, different weight Of sample, artificial mixed single phases sample and repeated experiment, the extracting ratio constants foil all phases in different infusions were obtained. The mathematical model which is on the basis of the stable extracting constant is established. Based on the purpose-control genetic algorithms, we only need to determine the total copper in the sample in different infusions under the selected condition, then the value of respective phase could be calculated. The-relative standard deviation are (%) free oxidized copper phase:1.5, conjunction oxidized copper phase: 17.6,, secondary copper sulfide phase: 1.9, primary copper sulfide phase : 2.7,total copper: 0.8.
Resumo:
The local electric-field distribution has been investigated in a core-shell cylindrical metamaterial structure under the illumination of a uniform incident optical field. The structure consists of a homogeneous dielectric core, a shell of graded metal-dielectric metamaterial, embedded in a uniform matrix. In the quasistatic limit, the permittivity of the metamaterial is given by the graded Drude model. The local electric potentials and hence the electric fields have been derived exactly and analytically in terms of hypergeometric functions. Our results showed that the peak of the electric field inside the cylindrical shell can be confined in a desired position by varying the frequency of the optical field and the parameters of the graded profiles. Thus, by fabricating graded metamaterials, it is possible to control electric-field distribution spatially. We offer an intuitive explanation for the gradation-controlled electric-field distribution.
Resumo:
The Ludox-QPS method is a newly developed technique, which combines the Ludox HS 40 density centrifugation and quantitative protargol stain, to enumerate marine ciliates with good taxonomic resolution. We tested the method for simultaneous enumeration of diatoms, protozoa and meiobenthos and compared its extraction efficiency for meiobenthos with that of the routine Ludox-TM centrifugation and a modified protocol using Ludox HS 40. We conducted the evaluation with a sample size of 8.3 ml each from sandy, muddy-sand and muddy sediments collected from the intertidal area of the Yellow Sea in summer 2006 and spring 2007. The Ludox-QPS method not only produced high extraction efficiencies of 97 +/- 1.3% for diatoms and 97.6 +/- 0.8% for ciliates, indicating a reliable enumeration for eukaryotic microbenthos, but also produced excellent extraction efficiencies of on average 97.3% for total meiobenthos, 97.9% for nematodes and 97.8% for copepods from sands, muddy sands and mud. By contrast, the routine Ludox-TM centrifugation obtained only about 74% of total meiobenthos abundance with one extraction cycle, and the modified Ludox HS 40 centrifugation yielded on average 93% of total meiobenthos: 89.4 +/- 2.0% from sands, 93 +/- 4.1% from muddy sands and 97.1 +/- 3.0% from mud. Apart from the sediment type, sample volume was another important factor affecting the extraction efficiency for meiobenthos. The extraction rate was increased to about 96.4% when using the same modified Ludox centrifugation for a 4 ml sediment sample. Besides the excellent extraction efficiency, the Ludox-QPS method obtained higher abundances of meiobenthos, in particular nematodes, than the routine Ludox centrifugation, which frequently resulted in an uncertain loss of small meiobenthos during the sieving process. Statistical analyses demonstrated that there were no significant differences between the meiobenthos communities revealed by the Ludox-QPS method and the modified Ludox HS 40 centrifugation, showing the high efficiency of the Ludox-QPS method for simultaneous enumeration of diatom, protozoa and meiobenthos. Moreover, the comparatively high taxonomic resolution of the method, especially for diatoms and ciliates, makes it feasible to investigate microbial ecology at community level.
Resumo:
The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was applied to the simultaneous determination of five organotin compounds (trimethyltin, dibutyltin, tributyltin, diphenyltin and triphenyltin) in seawater samples. Agilent TC-C18 column was used for the separation, the mobile phase of HPLC was CH3CN : H2O: CH3COOH=65 : 23 : 12 (phi), 0.05% TEA, and pH value was adjusted to 3.0 by diluent ammonia. The flow rate was 0.6 mL . min(-1). Five mixed organotin compounds in a mix standard solution from 100 to 0.5 mu g . L-1 were applied for the method assessment. The experimental results indicate that the correlation coefficient of calibration curves (R-2) for each organotin compound was over 0.998 and the detection limits of the five organotin compounds were lower than 3 ng . L-1. Different mixed organic solvents including dichloromethane or toluene were used for extraction of organotin and the extraction condition of organotin from seawater was optimized. The 100 mL seawater acidized by hydrochloric acid was extracted by 10 mL carbon dichloride (CH2Cl2) with 2% tropolone for 10 min twice. Extracted organic solvents were mixed And blown to one drop by nitrogen with the rate of 1.7 mL . min(-1), then 1 mL acetonitrile was added to the drop for redissolving the organotin compounds. Finally, the mixed redissolution was filtered by 0.22 mu m organic filter membrane before analysis. it was found that the only organotin compound in seawater was triphenyltin (TPHT) and the content was 53.2 ng . L-1. The recoveries test from the standard addition for diphenyltin (DPHT), dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPHT) were over 80%. However, the recovery for trimethyltin (TMT) was relatively low and the value was 50%. The reason might be attributed to the decomposition or adsorption of those compounds during the extraction procedure. Further study on this subject is in progress.
Resumo:
A sensitive and efficient method for simultaneous determination of glutamic acid (Glu), gamma-amino-butyric acid (GABA), dopamine (DA), 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) in rat endbrains was developed by high-performance liquid chromatography (HPLC) with fluorescence detection and on-line mass spectrometric identification following derivatization with 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC). Different parameters which influenced derivatization and separation were optimized. The complete separation of five neurotransmitter (NT) derivatives was performed on a reversed-phase Hypersil BDS-C-18 column with a gradient elution. The rapid structure identification of five neurotransmitter derivatives was carried out by on-line mass spectrometry with electrospray ionization (ESI) source in positive ion mode, and the BCEOC-labeled derivatives were characterized by easy-to-interpret mass spectra. Stability of derivatives, repeatability, precision and accuracy were evaluated and the results were excellent for efficient HPLC analysis. The quantitative linear range of five neurotransmitters were 2.441-2 x 10(4) nM, and limits of detection were in the range of 0.398-1.258 nM (S/N = 3:1). The changes of their concentrations in endbrains of three rat groups were also studied using this HPLC fluorescence detection method. The results indicated that exhausting exercise could obviously influence the concentrations of neurotransmitters in rat endbrains. The established method exhibited excellent validity, high sensitivity and convenience, and provided a new technique for simultaneous analysis of monoamine and amino acid neurotransmitters in rat brain. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
Molecular imprinting chiral stationary phase against Cbz-L-Serine (Cbz-L-Ser) and Cbz-L-Alaine (Cbz-L-Ala) were prepared utilizing acrylamide + 2-vinylpyridine as combined basic functional monomers. Cross-selectivity was used to obtain simultaneous chiral separations of Cbz-DL-Ser and Cbz-DL-Ala by connecting two columns packed with Cbz-L-Ser and Cbz-L-Ala imprinted chiral stationary phase, respectively.
Resumo:
A series of unsupported dimolybdenum nitride (gamma-Mo(2)N) catalysts differing in surface area were prepared by temperature programmed reduction of MoO(3) with a mixture of NH(3):N(2) (90:10). Characterization of catalysts by BET, XRD, TPR and XPS techniques was carried out. The samples were used as catalysts in hydrotreating reactions (simultaneous hydrodesulfurization of thiophene and hydrogenation of cyclohexene). Low surface area gamma-Mo(2)N materials show much higher specific conversions than those with higher surface area. These results indicate that HDS and HYD reactions over gamma-Mo(2)N seem to be structure-sensitive. The relative exposure extent of crystalline planes (111) and (200) over the different catalysts can be associated with their hydrogen adsorption capacities and with their catalytic performances. The catalytic activities are significantly affected by the catalyst pretreatment conditions. (C) 1999 Elsevier Science B.V. All rights reserved.
Resumo:
We consider the problem of matching model and sensory data features in the presence of geometric uncertainty, for the purpose of object localization and identification. The problem is to construct sets of model feature and sensory data feature pairs that are geometrically consistent given that there is uncertainty in the geometry of the sensory data features. If there is no geometric uncertainty, polynomial-time algorithms are possible for feature matching, yet these approaches can fail when there is uncertainty in the geometry of data features. Existing matching and recognition techniques which account for the geometric uncertainty in features either cannot guarantee finding a correct solution, or can construct geometrically consistent sets of feature pairs yet have worst case exponential complexity in terms of the number of features. The major new contribution of this work is to demonstrate a polynomial-time algorithm for constructing sets of geometrically consistent feature pairs given uncertainty in the geometry of the data features. We show that under a certain model of geometric uncertainty the feature matching problem in the presence of uncertainty is of polynomial complexity. This has important theoretical implications by demonstrating an upper bound on the complexity of the matching problem, an by offering insight into the nature of the matching problem itself. These insights prove useful in the solution to the matching problem in higher dimensional cases as well, such as matching three-dimensional models to either two or three-dimensional sensory data. The approach is based on an analysis of the space of feasible transformation parameters. This paper outlines the mathematical basis for the method, and describes the implementation of an algorithm for the procedure. Experiments demonstrating the method are reported.