Amino-Functionalized Lead Phthalocyanine-Modified Benzoxazine Resin: Curing Kinetics, Thermal, and Mechanical Properties.

Phenol-diaminodiphenylmethane-based benzoxazine (P-ddm)/phthalocyanine copolymer was prepared by using P-ddm resin as matrix and 3,10,17,24-tetra-aminoethoxy lead phthalocyanine (APbPc) as additive. Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA) were used to investigate the curing behavior, curing kinetics, dynamic mechanical properties, thermal stability, and impact strength of the prepared copolymers. The kinetic parameters for the P-ddm/APbPc blend curing processes were examined by utilizing the iso-conversional, Flynn-Wall-Ozawa, and Málek methods. The P-ddm/APbPc blends exhibit two typical curing processes, and DSC results confirmed that the blending of APbPc monomer can effectively reduce the curing temperature of P-ddm resin. The autocatalytic models also described the non-isothermal curing reaction rate well, and the appropriate kinetic parameters of the curing process were obtained. The DMA and impact strength experiments proved that the blending of APbPc monomer can significantly improve the toughness and stiffness of P-ddm resin, the highest enhancements were observed on 25 wt.% addition of APbPc, the recorded values for the storage modulus and impact strength were 1003 MPa and 3.60 kJ/m2 higher, respectively, while a decline of 24.6 °C was observed in the glass transition temperature values. TGA curves indicated that the cured copolymers also exhibit excellent thermal stabilities.

Changes in mortality and immunological variables of Litopenaeus vannamei parents and their filial families infected with white spot syndrome under different experimental conditions.

In order to find changes in mortality and immunological variables of Litopenaeus vannamei parents and the filial WSSV-resistant and -susceptible families after infection with WSSV under different experimental conditions, the haemolymph total haemocyte count (THC), phenoloxidase (PO), and superoxide dismutase (SOD) activities were measured at days 0, 1, 3, 6, 9, 12 and 15 after challenge and shrimp mortality was also recorded. When shrimps were challenged with 10(-3) (1.29x10(6)copiesmL(-1)), 10(-4) (1.29x10(5)copiesmL(-1)) or 10(-5) (1.29x10(4)copiesmL(-1)) WSSV stock solution (0.1mLshrimp(-1)), the cumulative mortalities (mean+/-S.E.) on day 15 were 100+/-0%, 79.3+/-1.1%, and 21.7+/-2.3%, respectively. Among shrimps challenged with 10(-4) (1.29x10(5)copiesmL(-1)) WSSV dilution (0.1mLshrimp(-1)), the cumulative mortalities (mean+/-S.E.) on day 15 in high-density (100shrimpsm(-3)), middle-density (50shrimpsm(-3)), and low-density (25shrimpm(-3)) groups were 95.5+/-0%, 84.7+/-0%, and 72.3+/-0%, respectively. The immunological variables including THC, PO, and SOD were decreased significantly at the beginning of infection stage, while these immunological variables for survivors reached almost the similar levels to the non-infection control group on day 15 after challenge with 10(-4) (1.29x10(5)copiesmL(-1)) WSSV dilution (0.1mLshrimp(-1)). Cumulative mortality (mean+/-S.E.) on day 15 in 17 filial families (G(2)) ranged from 13.3+/-1.9% to 100+/-0% when shrimps were challenged with 10(-4) (1.29x10(5)copiesmL(-1)) WSSV dilution (0.1mLshrimp(-1)). Although, the PO and SOD activities for shrimps in the WSSV-resistant family were slightly higher than those in the WSSV-susceptible family at the same sampling time after infection, these differences were not significant (p<0.05).

[Removal efficiency of the white spot syndrome virus in the membrane bioreactors].

White spot syndrome virus removal was performed in three submerged membrane bioreactors with the different membrane pore sizes. Samples were sampled from the influent, effluent and supernatant fluid in each MBR and were detected by a Taqman-based real-time PCR technology. When these MBRs with a pore of 0.45 microm, 0.22 microm, and 0.1 microm were treated the virus of WSSV isolated from the phosphorous buffer saline, the removal rate of WSSV could be achieved 0.6 lg, 1.18 lg, and 5.5 lg, respectively. The removal rate of the membrane module with a pore size of 0.45 microm was lowest than those of the other membrane modules. When the MBRs with the different pore sizes were treated the domestic aquaculture wastewater containing the WSSV, the removal efficiency of WSSV in the MBRs with a pore size of 0.22, 0.45 microm was increasing while the filtration resistance increased. It was revealed that the biofilm accumulating on the surface of the membrane made a major contribution to WSSV removal. No significant difference on the removal efficiency of WSSV was found (p > 0.05) in the MBRs on hour 12, the membrane with a pore size of 0.45 microm demonstrated an almost complete removal of WSSV (up to 5.35 lg).

[Preparation and characterization of the epitopes of SARS coronavirus spike protein].

AIM: To prepare the recombinant epitopes of SARS-CoV spike protein and study their antigenic property to spike protein. METHODS: The epitopes of SARS-CoV spike protein were analyzed by epitope prediction software. A novel gene, named Z, encoding 16 predicted epitopes of spike protein was designed and synthesized using chemical method. Z gene was cloned into vector pET-28a(+), expressed in E.coli BL21(DE3) and purified by Ni(2+) affinity method. Z protein was used as antigen to immunize the rabbit and anti-Z sera was collected. Then the antigenic property of Z protein to SARS-CoV spike protein was analyzed by dot-blot and ELISA assay. RESULTS: Z gene was successfully designed and expressed in E.coli BL21(DE3). Dot blot analysis showed that SARS-CoV spike protein, which was expressed and purified from mammal cells, can be detected by anti-Z sera from rabbit. ELISA analysis indicated the SARS-CoV antigen prepared from SARS-CoV lysates can be detected by anti-Z sera. CONCLUSION: The predicted epitopes of Z protein can induce the development of SARS-CoV spike protein antibody in rabbits, which provides a new protein for developing vaccine against SARS-CoV.

[HLA-DQA1 genotyping by using oligonucleotide microarrays].

In order to fabricate the HLA-DQA1 genotyping chip and develop an integrated, parallel technical platform to type HLA system, a pair of primers and a set of probes were designed according to the sequences of HLA-DQA1 exon 2, where the polymorphism is concentrated. The oligonucleotide chip was made with the methods developed in our laboratory. The target DNA was asymmetrically amplified with the labeled sense primer. The signals were scanned and analyzed after the hybridization between microarray and PCR product. The allele types of the samples were identified. The result was verified by the standard DNA and DNA sequencing. The results showed that the genotyping was successfully carried out in 50 standard DNA samples and 50 clinical samples. Among them, results of the 50 standard DNA samples matched their templates. In the other 50 samples, results of the randomly selected 10 matched their sequencing results except that two of them got the incompletely result. In reproducible tests, the signal reappear rate was 95%. It is concluded that HLA-DQA1 genotyping by using our array system is simple and convenient with satisfied accuracy and reproducibility.