Preparation of Rubber Accelerator Tetrabenzylthiuramdisulfide and Its Spectral Analysis.

In the study, rubber accelerator tetrabenzylthiuramdisulfide (TBzDT) was synthesized with two-step method with hydrogen peroxide as oxidant firstly. TBzDT was detected and characterized with XRD, FT-IR, TG-DTA. Its micro-structure was revealed. Chemical bond types into TBzDT molecule were revealed with FT-IR. TBzDT phase composition and structure were given by crystallographic data from XRD detecting such as cell parameters, crystal face index. The phase composition and qualitative identification of TBzDT structure were completed. Two kinds of information were detected with TG-DTA as to quality change and thermal effect. TBzDT phase transition and decomposition temperature were 142.5, 200.9 ℃ respectively. The decomposition temperature of TBzDT was relevtively high. It could provided reference with research on rubber vulcanizing properties by TBzDT on rubber vulcanizing machine. A little SC2 contained into TBzDT was revealed by FTIR, TG-DTA from different sides.

[Study on the Preparation of N-Tert-Butylbenzothiazole-2-Sulphenamide and Its Spectral Analysis].

In the study, N-tert-butylbenzothiazole-2-sulphenamide (TBBS) was synthesized with one-step method with hydrogen peroxide as the oxidant. TBBS was detected and characterized with FTIR，UV-Vis，XRD and TG-DSC. Its micro-structure and intrinsic regularity were revealed. Chemical bond types into TBBS molecule were revealed with FTIR. The final product was determined TBBS. Three absorption peaks were detected by UV-Vis at 228.3，281.5，298.3 nm respectively, due to n→σ*，π→π*，n→π* electronic transitions. It could provide experimental basis with enterprise to test TBBS product quality and speculate its structure. The phase composition and structure of TBBS were revealed by crystallographic data from XRD detecting such as cell parameters, crystal face index. The phase composition and qualitative identification of TBBS structure were completed. Two kinds of information were detected by TG-DSC as quality change and thermal effect. The DSC curve of TBBS was very complex. There were a small absorption peak of 53.3 ℃ as a small amount of tert-butylamine containing in TBBS was oxidized. Three exothermic peaks of 117.4，269.2，373.7 ℃, due to transition peak and decomposition phase of TBBS respectively. The decomposition temperature of TBBS was very high. It could provide reference for research on rubber vulcanizing properties by TBBS on rubber vulcanizing machine. This study could provide the basis experimental data on the enterprises to designate the working standard tracing detection of TBBS industrialized production. The performance index of TBBS was judged. The project of TBBS industry standard could be declared by the enterprises, written a draft standard.

[Preparation of Rubber Accelerator Tetraisobutylthiuram Monosulfide and Its Spectral Analysis].

In the study, rubber accelerator tetraisobutylthiuram monosulfide (TiBTM) was synthesized by two-step method with hydrogen peroxide as oxidant firstly. TiBTM was detected and characterized by FTIR, XRD, TG-DSC. Its micro-structure and intrinsic regularity were revealed. Chemical bond types into TiBTM molecule were revealed by FTIR. TiBTM phase composition and structure were given by crystallographic data from XRD detecting such as cell parameters, crystal face index. The phase composition and qualitative identification of TiBTM structure were completed. Two kinds of information were detected by TG-DSC as quality change and thermal effect. TiBTM phase transition and decomposition temperature were 75.1 and 287.0 ℃ respectively. Uhe decomposition temperature of TiBTM was very high, samples possessing with high purity, without other impurities. It could provided reference with research on rubber vulcanizing and multiple functional properties by TiBTM on rubber vulcanizing machine. This study can provide the basis experimental data on the enterprises to designate the working standard tracing detection of TiBTM industrialized production. The best technological conditions and parameters could be provided for the enterprises to adopt cleaner production process of TiBTM. Performance index of TiBTM was judged. The project of TiBTM industry standard can be declared by the enterprises, written a draft standard.

[Preparation of Zinc O,O,O',O'-Tetrabutyl Bis(Phosphorodithioate) and Its Spectral Analysis].

In the study, zinc O,O,O',O'-tetrabutyl bis(phosphorodithioate) (ZBPD) was synthesized with two-step method firstly. ZBPD was detected and characterized with UV-vis, FT-IR andTG-DSC. Its micro-structure and intrinsic regularity were revealed. Two absorption peaks were detected with UV-Vis at 212.0 and 227.0 nm respectively caused by n→σ*, π→π* electron transition. The intensity of peaks was changed with the regularity with different ZBPD concentration. It could provide the basic data with the enterprise of ZBPD product quality inspection. Chemical bond types into ZBPD molecule were revealed by FT-IR. Two kinds of information were detected by TG-DSC as quality change and thermal effect. The DSC curve of ZBPD was very complex. There were a wide absorption peak of 84.3 ℃, four exothermic peaks of 245.0, 344.3, 476.1, 344.3 ℃, due to the molecular structure of ZBPD and small amounts of impurities. The decomposition temperature of ZBPD was very high. It could provided reference with research on rubber vulcanizing properties by ZBPD on rubber vulcanizing machine. This study could provide the basis experimental data on the enterprises to designate the working standard tracing detection of ZBPD industrialized production. Performance index of ZBPD was judged. The project of ZBPD industry standard could be declared by the enterprises, written a draft standard.

[Preparation of TBSI with NS-Acetic Anhydride Method and Its Spectral Analysis].

In the study, N-t-butyl-2-benzothiazole sulfenimide (TBSI) was prepared by NS-acetic anhydride method with acetic anhydride as solvent. It was detected with FTIR, XRD, UV-Vis, TG-DTA. Micro-structure and essence disciplinarian of them were disclosed. Chemical bond types into TBSI molecule were revealed with FTIR. TBSI phase composition and structure were revealed with crystallographic data from XRD detecting such as cell parameters and crystal face index. The phase composition and qualitative identification of TBSI structure were completed. The absorption peaks were detected by UV-vis at 228.3, 281.3 and 298.3 nm, respectively caused by n→σ*, π→π*, n→π* electron transition. It could provide basic data with the enterprise of ZBPD product quality inspection. Two kinds of information were detected with TG-DTA as quality change and thermal effect. There were three absorption peaks of 46.5, 188.9, 368. 5 ℃ due to a few residual solvent volatilization in the sample, phase transition peak and decomposition peak. The decomposition temperature of TBSI was very high. It could provided reference with research on rubber vulcanizing properties with TBSI on rubber vulcanizing machine. This study could provide basis experimental data on the enterprises to designate the working standard tracing detection of TBSI industrialized production. Performance index of TBSI was judged. The project of TBSI industry standard could be declared by the enterprises, written a draft standard.

Comprehensive evaluation of the adenovirus/alphavirus-replicon chimeric vector-based vaccine rAdV-SFV-E2 against classical swine fever.

Classical swine fever (CSF) is an economically important, highly contagious swine disease caused by classical swine fever virus (CSFV). Marker vaccines and companion serological diagnostic tests are thought to be a promising strategy for future control and eradication of CSF. Previously, we have demonstrated that an adenovirus-vectored Semliki forest virus replicon construct expressing the E2 glycoprotein from CSFV, rAdV-SFV-E2, induced sterile immunity against a lethal CSFV challenge. In this study, we further evaluated the vaccine with respect to its safety, number and dose of immunization, and effects of maternally derived antibodies, re-immunization of the vaccine or co-administration with pseudorabies vaccine on the vaccine efficacy. The results showed that: (1) the vaccine was safe for mice, rabbits and pigs; (2) two immunizations with a dose as low as 6.25×10(5) TCID(50) or a single immunization with a dose of 10(7) TCID(50) rAdV-SFV-E2 provided complete protection against a lethal CSFV challenge; (3) maternally derived antibodies had no inhibitory effects on the efficacy of the vaccine; (4) the vaccine did not induce interfering anti-vector immunity; and (5) co-administration of rAdV-SFV-E2 with a live pseudorabies vaccine induced antibodies and protection indistinguishable from immunization with either vaccine administered alone. Taken together, the chimeric vaccine represents a promising marker vaccine candidate for control and eradication of CSF.

Enhancement of the immunogenicity of an alphavirus replicon-based DNA vaccine against classical swine fever by electroporation and coinjection with a plasmid expressing porcine interleukin 2.

Alphavirus replicon-based DNA vaccines have emerged as a promising approach to generation of antigen-specific immune responses. However, due to their low immunogenicity, there is a need for other approaches to enhance the vaccine potency. In this study, electroporation (EP) and a plasmid expressing porcine interleukin 2 (IL-2) were used to improve the immunogenicity of an alphavirus replicon-based DNA vaccine pSFV1CS-E2 against classical swine fever (CSF). Pigs were immunized with pSFV1CS-E2 alone or together with IL-2 by EP or by simple intramuscular injection. The results showed that EP combined with IL-2 resulted in marked enhancement of E2-specific antibody responses. Moreover, CSFV-specific lymphocyte proliferation, IFN-γ and IL-4 responses were increased significantly in the pSFV1CS-E2+IL-2/EP group. Pigs immunized with pSFV1CS-E2 plus IL-2 by EP were completely protected from lethal challenge, which is comparable to the sterilizing immunity and full protection offered by the live attenuated vaccine C-strain and in contrast with the incomplete protection conferred by pSFV1CS-E2 without or with IL-2 or EP alone, as demonstrated by the presence of pathological changes or/and viral loads. We conclude that EP in combination with IL-2 can significantly improve the immunogenicity of the plasmid DNA vaccine.

A novel alphavirus replicon-vectored vaccine delivered by adenovirus induces sterile immunity against classical swine fever.

Low efficacy of gene-based vaccines due to inefficient gene delivery and expression has been major bottleneck of their applications. Efforts have been made to improve the efficacy, such as gene gun and electroporation, but the strategies are difficult to put into practical use. In this study, we developed and evaluated an adenovirus-delivered, alphavirus replicon-vectored vaccine (chimeric vector-based vaccine) expressing the E2 gene of classical swine fever virus (CSFV) (rAdV-SFV-E2). Rabbits immunized with rAdV-SFV-E2 developed CSFV-specific antibodies as early as 9 days and as long as 189 days and completely protected from challenge with C-strain. Pigs immunized with rAdV-SFV-E2 (n=5) developed robust humoral and cell-mediated responses to CSFV and were completely protected from subsequent lethal CSFV infection clinically and virologically. The level of immunity and protection induced by rAdV-SFV-E2 was comparable to that provided by the currently used live attenuated vaccine, C-strain. In contrast, both the conventional alphavirus replicon-vectored vaccine pSFV1CS-E2 and conventional adenovirus-vectored vaccine rAdV-E2 provided incomplete protection. The chimeric vector-based vaccine represents the first gene-based vaccine that is able to confer sterile immunity and complete protection against CSFV. The new-concept vaccination strategy may also be valuable in vaccine development against other pathogens.

Experimental infection of Bama miniature pigs with a highly virulent classical swine fever virus.

BACKGROUND: Currently, larger domestic pigs are only animals widely used in vaccine evaluation and pathogenicity study of classical swine fever virus (CSFV). This study was aimed to create an alternative animal experimental infection model of CSFV. RESULTS: Twenty specific-pathogen-free Bama miniature pigs were randomly divided into two groups and rooms, infected and non-infected, and the pigs in the infected group were inoculated intramuscularly with 104, 105 or 106 TCID50 (median tissue culture infective dose) CSFV Shimen strain (n = 5 × 3) or left uninoculated to serve as in-contact pigs (n = 3). The uninfected control pigs (n = 2) were housed in a separate room. Clinical signs, body temperature, viraemia, tissue antigen distribution, pathological changes and seroconversion were monitored. Clinical signs were observed as early as 2 days post-inoculation (dpi) in all infected pigs (though mild in contact pigs), but not non-infected control pigs. All inoculated pigs showed viraemia by 6 dpi. The in-contact pigs showed lower levels of viraemia. At 10 dpi, seroconversion was noted in five of the 15 inoculated pigs. All inoculated or one in-contact pigs died by 15 dpi. CONCLUSIONS: These results show that Bama miniature pigs support productive CSFV infection and display clinical signs and pathological changes consistent with CSFV infections observed in larger domestic pigs.