A recombinant strain of Salmonella choleraesuis C500,containing a eukaryotic expression plasmid pBO1 with the immune-dominant epitope of foot-and-mouth disease virus,was *** immune response to this recombinant strain ...
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A recombinant strain of Salmonella choleraesuis C500,containing a eukaryotic expression plasmid pBO1 with the immune-dominant epitope of foot-and-mouth disease virus,was *** immune response to this recombinant strain was evaluated by oral administration of the recombinant live bacteria pBO1/*** in *** showed that T cell response and specific antibody production were *** approach may present a general strategy for eliciting immune responses with DNA vaccine delivered by live bacterial *** stimulated indexes of T lymphoproliferation by specific antigens of FMDV in rabbits,can reach up to 11.0 and an antibody titer of 1/32 as detected in the erum with liquid block ELISA.
On p. 3153, Guang‐Hui Ma and co‐workers report on the development of autofluorescent chitosan microspheres with tunable color based on different crosslinking reagents and further chemical modification. The fluoresce...
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On p. 3153, Guang‐Hui Ma and co‐workers report on the development of autofluorescent chitosan microspheres with tunable color based on different crosslinking reagents and further chemical modification. The fluorescent intensity can also be controlled by the particle size and crosslinking degree. The autofluorescent microspheres may be useful in fluorescence assays as bright, inexpensive, and stable probes for qualitative and quantitative studies of biological interactions and drug delivery. Fluorescent microspheres are widely used as biological tracers. In this study, uniformly sized chitosan microspheres crosslinked with glutaraldehyde (CG microspheres) and formaldehyde (CF microspheres) are successfully prepared by the Shirasu Porous Glass (SPG) membrane emulsification technique. Selectively reduced CG microspheres (SRCG microspheres) are obtained by NaBH 4 reduction. These chitosan microspheres are found to exhibit fluorescent properties without conjugation to any fluorescent agent. The fluorescence color varies with different crosslinkers and can be modulated by further chemical reduction, whereas the fluorescence intensity can be controlled by tuning the particle size and degree of crosslinking. The autofluorescence of the microspheres is applied to study the phagocytosis of HepG2 cells using the microspheres as novel tracers. Quantitative and qualitative evaluations show that these chitosan microspheres serve as bright, inert, durable, and extremely photostable tracers.
An rCHO cell line expressing recombinant human prourokinase （pro-UK） at the level of 5μg/ 10^6cells/d was cultivated on Cytopore cellulose porous microcarriers in a 7.5L Biostat CT stirred tank reactor. A periodic ...
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An rCHO cell line expressing recombinant human prourokinase （pro-UK） at the level of 5μg/ 10^6cells/d was cultivated on Cytopore cellulose porous microcarriers in a 7.5L Biostat CT stirred tank reactor. A periodic pressure oscillation of 0.04 MPa and 0.04 Hz was adopted to introduce a physical stimulus on the rCHO cells and to improve mass transfer characteristic between cells and medium in the process of porous microcarrier CHO cell culture. Compared to constant pressure culture, the oscillation culture didn＇t influence specific cell growth rate significantly, but could enhance the pro-UK specific production by 10% - 40%, and reduce production of lactate by 10% - 30%. In the perfusion culture of recombinant CHO cell with serum-free medium for 67 days, cell density could reach 2.64×10^7/ml, the maximal prourokinase concentration in harvested supernatant was about 118mg/L, a total of 21.1 grams of prourokinase was produced in 313 liters of supernatant. In conclusion, the perfusion cell culture with periodic pressure oscillation can enhance the production of recombinant protein and increase the reactor specific productivity.
The phase behavior of ionic liquids aqueous two-phase (ILATPS) was investigated. It was found that the additive salt had little effect on the phase equilibrium of aqueous two-phase. The effect of anion mainly obeyed t...
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The phase behavior of ionic liquids aqueous two-phase (ILATPS) was investigated. It was found that the additive salt had little effect on the phase equilibrium of aqueous two-phase. The effect of anion mainly obeyed the Hofmeister rule, and the formation of ILATPS could be promoted by the increase of the hydrophobicity of anion. The formation of ILATPS could also be promoted by the increase of polarity of the head group, and by the increase of the side-chain length of ionic liquids, but the effect was weaker than that anion. An elevated temperature would inhibit the formation of ILATPS for short-chain ionic liquids, but would promote the formation of ILATPS for long-chain ionic liquids.
The aggregation behavior of ionic liquids into micelle was studied. It was found that the micellization of ionic liquids was governed by its side-chain length, head structure and anion species, which could be promoted...
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The aggregation behavior of ionic liquids into micelle was studied. It was found that the micellization of ionic liquids was governed by its side-chain length, head structure and anion species, which could be promoted by increasing hydrophobicity, such as a long side-chain length, a hydrophobic anion or C2-methylated head. The side-chain length played the most active role in comparison with head group and anion. The micellization of ionic liquids would be weakened with increasing temperature.
In order to characterize the interdependence of all the factors directly in the process of bioleaching polymetallic nodules in deep sea, this paper conducted the aerobic and anaerobic leaching experiments of a microbe...
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In order to characterize the interdependence of all the factors directly in the process of bioleaching polymetallic nodules in deep sea, this paper conducted the aerobic and anaerobic leaching experiments of a microbe catalysis MnO2-FeS2-H2SO4 system. The dynamic model of valuable metals by microbe catalysis leaching under anaerobic condition, that is the shrinking core model, was established using the DLVO theory. In the oxidation-reduction process of polymetallic nodules and pyrites, the Mn-leaching mechanics under anaerobic condition was the circulate transformation between Fe2+ and Fe3+ by microbe catalysis. The microbes absorbed on the surface of mineral and accelerated the reaction process, the mineral particles got small continuously during the reaction. The further study on the experiments indicates that retract model curves fit the experimental ones nicely, which verified the reliability of the model.
There were three ways to reduce metal oxides by metal reducing microorganisms: direct contact, electron shuttling and chelation of insoluble metal oxides. A microbial fuel cell by Geobacter metallireducens was used to...
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There were three ways to reduce metal oxides by metal reducing microorganisms: direct contact, electron shuttling and chelation of insoluble metal oxides. A microbial fuel cell by Geobacter metallireducens was used to investigate the influence of the three paths on the rate of dissimilatory iron reduction. The results indicate that in the process of dissimilatory metal reduction, NTA and AQDS can accelerate the speed of ferric oxides reduction and magnetite generation in the initial stage, but magnetite production prevents further iron reduction. Direct contact is a very important way, and the biomembrane formed by adsorption for long time is a critical factor for reduction. Electron shuttling plays a less important role after most of mineral oxides surfaces have been enclosed by microorganisms.
Four heterotrophic microbes were separated from deep sea floor sediment of the Pacific Ocean. The dissimilatory reduction principles of these heterotrophic microbes were explored after their acclimatization to acid an...
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Four heterotrophic microbes were separated from deep sea floor sediment of the Pacific Ocean. The dissimilatory reduction principles of these heterotrophic microbes were explored after their acclimatization to acid and metals. The results indicate that anaerobic leaching is better than aerobic condition, the optimum pH range is 2.5 to 3, the leaching time is 3 d, and the leaching rate is up to 98%. It shows that dissimilatory reduction of marine nodules with heterotrophic microbes has such advantages as higher leaching rate, no ventilation, lower investment, easier operation and better environment. The solid and organic waste can be treated at the same time coupling valuable metal recovery.
The electron transfer process of microbe on the mineral surface was studied by the use of a microbe fuel cell. The results indicate that direct contact plays an important role in the process of reducing Fe (OH)3 with ...
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The electron transfer process of microbe on the mineral surface was studied by the use of a microbe fuel cell. The results indicate that direct contact plays an important role in the process of reducing Fe (OH)3 with Geobacte metallireducens, and the bio-film absorbed on the mineral surface is a key factor. Bio-film formation needs a relative long time. It is an important metabolic way to form bio-film by cell-absorption on the solid surface. Although mediate AQDS accelerates the reduction rate effectively at the early stage, but its effectiveness is not significant after the cell-absorption. So the microbe catalysis mineral oxidation-reduction reaction is influenced by bio-film. Accelerating the film formation on the mineral surface and keeping its stability are very important for the microbe leaching rate.
Molecular structure and IR spectrum data of alkyllimidazolium chloride were calculated successfully by density function theory. The computational results were confirmed by experimental data. The three alkyllimidazoliu...
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Molecular structure and IR spectrum data of alkyllimidazolium chloride were calculated successfully by density function theory. The computational results were confirmed by experimental data. The three alkyllimidazolium chlorides of unknown geometries and IR spectrum were predicted. The 1-buyl-3-methyl-imidazolium chloride was synthesized and determined by IR spectrum. It was demonstrated that simulating calculation of the molecular structure and IR spectrum of the synthesized product were reasonable.
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