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ABSTRACT: To study the structure and function of a newly found virus strain Spodoptera litura multicapsid nucleopolyhedrovirus II (SpltMNPVII) ORF146 gene.
The primers were designed according to the sequence of SpltMNPVII genome. The promoter of ORF146 was amplified by PCR. The promoter activities and the time course of mRNA transcription were analyzed. The fragment of the ORF146 gene was then cloned into the vector of pET28a(+) and expressed. The polyclonal antibody was prepared by using the purified fusion protein. Titration determination of anti-ORF146 antibody was evaluated by ELISA.
Nucleotide sequence analysis demonstrated that this gene has a 1383 bp ORF, encoding 460 amino acids with a predicted molecular weight of 50.4 kDa. Analysis of both promoter activities and the time course of mRNA transcription of the ORF146 gene showed that ORF146 was transcripted in early stage as well as in late stage. The transcription began at 2 h post infection (hpi) and reached two peaks at 8 and 18 hpi and then the transcription level was slightly decreased from 24 hpi. pET-28a-ORF146 fusion protein expressed in prokaryotic and purified polyclonal antibody was with good specificity, with the titer above 1:3200.
SpltMNPV II ORF146 gene is a composition structure protein, which was expressed at both early and late stage. ORF146 might be involved in viral DNA replication. The polyclonal antibody can be used to further study the biological characteristics and functions of proteins.
ACTA MICROBIOLOGICA SINICA 12/2010; 50(12):1600-6.
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ABSTRACT: We undertook this study to determine the minimum necessary volume of various grades of fatty liver grafts in reduced-size orthotopic liver transplantation (ROLT) and to elucidate the property of fatty liver regeneration.
By modified two-cuff technique, ROLT of different rats was performed with various grades and volumes of fatty liver grafts. The survival rate, graft-to-recipient body weight ratio (GRWR), standard liver volume (SLV) and liver function were detected to determine appropriate steatotic grafts that could be safely adopted in ROLT.
In grade II macrovesicular steatosis (MaS) grafts, the 1-week survival rate of 70% ROLT was significantly worse (25%). In grafts with microvesicular steatosis (MiS) undergoing 70%, 60%, and 50% ROLT, 7-day survival decreased according to the graft volume (75%, 75%, and 33.3%). Proliferating cell nuclear antigen (PCNA) and 5-bromo-2'-deoxyuridine (BrdU) labeling index in normal liver graft reached the highest on postoperative day (POD) 3, whereas in fatty grafts the expression peak was on POD 7. Liver regeneration ratios of normal liver graft were higher than mild MaS graft, but grade II MaS grafts hardly regenerated. When compared with moderate MaS grafts B2 (70% ROLT) and mild MaS grafts A3 (60%) groups, the disparities of alanine aminotransferase and total bilirubin were significant.
In successful and long-term survival of rat ROLT, MiS or grade II MaS livers could be safely used as grafts only when their GRWR >2.29+/-0.20 (or 2.28+/-0.12) % and SLV >60%; MaS livers in grade II should not be used as grafts. Hepatic regeneration potential of mild MaS or MiS with any grade graft is not obviously impaired after ROLT, but delayed proliferative peak and prolonged cell proliferative cycle are shown.
Archives of medical research 05/2009; 40(3):146-55. · 1.88 Impact Factor
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ABSTRACT: Calcium carbonate (CaCO3)/poly(methyl methacrylate) (PMMA) composite microspheres were synthesized in a soapless emulsion polymerization process. CaCO3 nanoparticles were pretreated with oleic acid to improve the compatibility between CaCO3 and the monomer methyl methacrylate, and this effectively enhanced the mass fraction of CaCO3 in the composite. The results of the thermogravimetric analysis showed that the thermal stability of the composite microspheres was better than that of PMMA. X-ray diffraction and Fourier transform infrared were applied to investigate the chemical and physical properties of the composite microspheres, and the results proved that the composites were composed of CaCO3 and PMMA. Scanning electron microscopy and transmission electron microscopy pictures showed that the morphology of the composite microspheres was uniform, and the CaCO3 nanoparticles could be well dispersed in the polymeric matrix. The soapless emulsion polymerization process effectively increased the filling amount of CaCO3 in the composite microspheres. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Journal of Applied Polymer Science 05/2007; 105(5):2925 - 2929. · 1.29 Impact Factor
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ABSTRACT: A carbonation process for the synthesis of active super-fine calcium carbonate particles from Ca(OH)(2) slurry at room temperature using a CO(2)-N(2) gas mixture was investigated. Industrial octadecyl dihydrogen phosphate (A) was added as a size-controlling additive and modifier in different reaction periods according to the pH of the medium. Analysis of the reaction products led to the conclusion that the addition of A in the digestion period could inhibit the crystal growth of calcium carbonate, while the addition of A at pH 7 of the medium could modify the surface character of the calcium carbonate particle, which was found to exhibit hydrophobic properties. From transmission electron microscopy (TEM), the hydrophobic property was attributed to the deposition of calcium alkyl phosphates, produced in the reaction mixture, onto the surface of calcium carbonate particle. IR spectra and TGA analysis of the obtained products indicated that A was bound onto the crystalline CaCO(3).
Journal of Colloid and Interface Science 05/2004; 272(2):326-9. · 3.07 Impact Factor
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ABSTRACT: The dendrite-shaped aragonite particles have been synthesized through the carbonation route, in which CO2 gas is bubbled through aqueous slurry of calcium hydroxide, in the presence of polyacrylic acid (PAA) at high temperature. The as-prepared products were characterized with scanning electron microscope, X-ray diffraction and transmission electron microscope with selected area electron diffraction. It was found that the dendrite-shaped aragonite particle present the single-crystal feature. The effects of the reaction temperature and the concentration of PAA on the crystal polymorphs and morphologies of the as-prepared calcium carbonate were investigated. The results showed that both the organic additive and the reaction temperature turned out to be important parameters for the biomimetic synthesis of the dendrite-shaped aragonite particle. This research may provide new insight into the control of the polymorphs and morphologies of calcium carbonate.
Colloids and Surfaces A: Physicochemical and Engineering Aspects.
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ABSTRACT: A soapless emulsion polymerization method was applied to synthesize CaCO3/PMMA spherical composite with different loading of CaCO3. CaCO3 nanoparticles were pretreated with oleic acid after the carbonation process of Ca(OH)2 slurry by CO2, in order to improve the compatibility between the CaCO3 particles and MMA monomer in emulsion system. The results of photon correlation spectroscopy (PCS) showed the particles size of composites were bigger than the pure PMMA. And the size increased with the increase of the content of CaCO3 nanoparticles. TEM images showed that the morphology of the composite microspheres was uniform and CaCO3 nanoparticles can be well encapsulated in the polymeric microsphere, and were located at the edge of the spheres. The results of DTG and TG indicated that the CaCO3 nanoparticles could improve the thermal stability of PMMA. Moreover, capsulation of CaCO3 by PMMA can increase the acid-resistant of CaCO3 nanofillers.
Colloids and Surfaces A: Physicochemical and Engineering Aspects.
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ABSTRACT: CaCO3/polystyrene inorganic/organic composite nanoparticles (80 nm) with a core/shell structure were obtained by in situ emulsion polymerization of styrene (St) on the surface of modified CaCO3 nanoparticles. The nanometer CaCO3 slurry was prepared via carbonation of a Ca(OH)2 slurry in the presence of sodium oleate at room temperature in order to introduce polymerizable groups onto its surface. TEM photographs of composite particles with a well-defined core-shell structure gave direct evidence of encapsulation. In addition, TGA and FT-IR spectra of the products after extraction indicated tight encapsulation between PS and CaCO3.
Materials Letters. 60(27):3248-3250.
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ABSTRACT: Hydrophobic CaCO3 particles were directly prepared via carbonation of Ca(OH)2 slurry in the presence of sodium oleate at room temperature. Sodium oleate was used to modify the surface property of CaCO3 particles. The measurement of relative contact angle and active ratio indicated that CaCO3 samples were hydrophobic. DTG, FT-IR and TEM analysis of the obtained product indicated that the hydrophobic property was attributed to the deposition of calcium oleate, produced in the reaction mixture, onto the surface of calcium carbonate particles. They were covered on the CaCO3 crystals surface and modified their surface property; at the same time they own CC bonds and could be polymerized or copolymerized later to give a polymeric monolayer.
Applied Surface Science 253(4):1983-1987. · 2.10 Impact Factor
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ABSTRACT: Hydrophobic CaCO3 particles were prepared in situ by carbonation of Ca(OH)2 slurry in the presence of the ethanol solution of oleic acid by mimicking the process of biomineralization. The weight ratio of oleic acid to CaCO3 changed from 0.3 to 3 wt.%. By changing the weight ratio of oleic acid to CaCO3, the surface property of CaCO3 particles was changed from hydrophilic to hydrophobic. Floating test and contact angle analysis of the obtained product indicated that the final CaCO3 obtained was hydrophobic. From the floating test, the active ratio of the modified CaCO3 might reach 100%. The contact angle of the modified CaCO3 was 108.77. IR spectrums of the CaCO3 particles showed the appearance of the alkyl groups from the oleic acid. We have succeeded in surface modification of CaCO3 with the hydrophobic oleic acid.
Materials Science and Engineering: C. 27(1):42-45.
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ABSTRACT: CaCO3/PEEK (poly-ether ether ketone) composites were prepared on a twin-screw extruder with different mass ratio of CaCO3/PEEK from 0% to 30%. Four types of particles were used as filler in PEEK matrix. The influence of surface treatment with sulfonated PEEK (SPEEK) of the particles on the mechanical and thermal properties of the composites was studied. The experiments included tensile tests, flexural tests, notched Izod impact tests, TGA, DSC and SEM. The modulus and yield stress of the composites increased with CaCO3 particles loadings. This increase was attributed to the bonding between the particles and the PEEK matrix, as can be proved by the SEM pictures of tensile fracture surface of the composites. The impact strength of the composites was modified by the SPEEK coated on the CaCO3 particle surface. DSC experiments showed that the particle content and surface properties influenced the glass transition temperature (Tg) and melting temperature (Tm) of the composites. The Tg increased with the content of fillers while Tm decreased. In this study the fillers treated were found to give better combination properties, which indicated that SPEEK played a constructive role in the CaCO3/PEEK composites.
European Polymer Journal.
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ABSTRACT: Hydrophobic vaterite nanoparticles were prepared via crystallization of CaCO3 with oleic acid in methanol by mimicking the process of biomineralization. The molar ratio of oleic acid to calcium ion was varied from 0.1 to 0.5. By changing the concentration of the oleic acid, CaCO3 particles with different shapes and polymorphism were obtained. High concentration of the oleic acid gave stable vaterite crystals, the polymorph of which did not change when the composite was kept in water for more than one week. Fourier transform infrared spectroscopy (FT-IR) and TGA analysis of the obtained product indicated that the oleic acid was bound to the crystalline CaCO3. The contact angle of the modified vaterite reached 122°. We have succeeded in crystallization of hydrophobic CaCO3 nanoparticles in situ.
Applied Surface Science.
