In this work, the trend in the performance of carbon fiber (CF) and its composite during self-polymerization of polydopamine (PDA) at carbon fiber surface was investigated by varying the self-polymerization time of dopamine in an aqueous solution. Research has shown that the PDA coating elevated the surface roughness and polarity of the inert fiber. The tensile strength of single carbon fiber was significantly improved, especially after 9 h of polydopamine self-polymerization, increasing by 18.64% compared with that of desized carbon fiber. Moreover, the interlaminar shear strength (ILSS) of CF-PDA9-based composites was 35.06% higher than that of desized CF-based composites. This research will provide a deep insight into the thickness and activated ingredients of dopamine oxidation and self-polymerization on interfacial compatibility of carbon fiber/epoxy resin composites.
Cewebrity is somebody who is only, or perhaps mostly famous through their presence on the Internet, an internet person who crosses over to the mainstream, so called web celebrity or Internet celebrity. Recognizing that Internet celebrities’ participation will bring about improvements of company performance, marketers have considered them to be new source of innovation dedicating to company’s success. For example, fashion companies believe that Internet celebrities have good innovation ideas on clothing collocation or even fashion design. Given the relevance of Internet celebrity in practice, researchers have begun to address its merits (Stever and Lawson, 2013). However, it is not yet a well-established field of academic inquiry, because Internet celebrity’s specific characteristics has not been well developed yet. Based on the nature of Internet celebrity as consumer, the theory of customer value co-creation is appropriate to explain these new generated celebrities’ activities in new product development. Activities of Internet celebrities in value co-creation can be shown as communication, idea conception, and product design (Genc and Benedetto, 2015). The current study mainly focuses on the effects of fashion internet celebrities on whole process of product development including product design, production, and commercialization by developing the scale of internet celebrity’s attributes under the perspective of customer value co-creation. Theoretically, the study fills up the research gap that no prior research develops the scales of Internet celebrity and test its effects on new product development. Practically, our work is highly useful for marketers understand the effects of Internet celebrity, thus developing appropriate strategies to utilize them.
ORF78 (ac78) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a baculovirus core gene of unknown function. To determine the role of ac78 in baculovirus life cycle, an ac78-deleted mutant AcMNPV, Ac78KO, was constructed. Quantitative PCR analysis revealed that ac78 is a late gene in the viral life cycle. After transfection into Spodoptera frugiperda cells, Ac78KO produced a single-cell infection phenotype indicating that no infectious budded viruses (BVs) were produced. The defection in BV production was also confirmed by both viral titration and Western blot. However, viral DNA replication is unaffected. Analysis of BV and occlusion derived virus (ODV) revealed that AC78 is associated with both forms of the virions and is a structural protein located to viral envelope. Electron microscopy showed that ac78 also plays an important role in embedding of ODV into occlusion body. This study therefore demonstrates that AC78 is a late virion associated protein and is essential for the viral life cycle.
ORF11 (ac11) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a highly conserved gene of unknown function. To determine the role of ac11 in baculovirus life cycle, an ac11-knockout mutant AcMNPV, Ac11KO, was constructed. qPCR analysis revealed that ac11 is an early gene in the life cycle. After transfection into Spodoptera frugiperda cells, Ac11KO produced a single cell infection phenotype indicating that no infectious budded viruses (BVs) were produced. The defection in BV production was confirmed by both viral titration and Western blot. However, viral DNA replication is unaffected. Electron microscopy showed that ac11 is required for nucleocapsids envelopment to form ODV and their subsequent embedding into OB. This study therefore demonstrates that ac11 is an early gene which is essential for the viral life cycle.
Among 154 putative ORFs of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), ac78 and ac79 are highly conserved genes in baculovirus, but their functions in the virus life cycle have been unknown so far. To determine their roles in AcMNPV replication, knockout mutants, ac78KO and ac79KO, were constructed using the plasmid capture system (PCS). Real-Time PCR analysis showed that both of ac78 and ac79 transcripts were first detected at 6 hours post-infection, and accumulated to maximum at 24 hours post-infection, suggesting that both of ac78 and ac79 are belong to late gene. When the genomic DNA of ac78KO was transfected into Sf9 cells, viral replication was restricted to a single cell infection. These results demonstrated that the ac78 play an important role in BV production, and therefore is essential for AcMNPV to mount a successful infection. Whereas Sf9 cells infected with the ac79KO showed normal viral symptoms such as rounding and swelling, OBs were not observed from majority of infected cells. These results suggested that the ac79 might play an important role in OB production.
Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus within the family Reoviridae, is the causative agent of maize rough dwarf and rice black-streaked dwarf diseases, both of which can lead to severe yield losses in east Asia. Although molecular approaches such as RT-PCR have potential for detection and diagnosis of this virus infections, their impact on high throughput certification is still limited. Therefore, the development of an antibody-based assay for rapid and effective diagnosis of RBSDV is preferable. In this study, we collected RBSDV from rice with rough dwarf disease and its complete nucleotide sequences of 10 genomic segments encoding 12 non-overlapping ORFs were determined. Among 12 ORFs, ORF1, 2 and 12 showed high level of similarities with the RdRp, major core protein and major outer shell protein, respectively. These ORFs were expressed as polyhedrin fusion protein or full-length soluble protein using baculovirus expression system for the preparation of specific antibody against RBSDV, which could be useful for the detection and diagnosis of this virus.
We isolated two baculoviruses, Spodoptera litura granulovirus (SlGV) and S. litura nucleopolyhedrovirus (SlNPV) in the dead larvae of S. litura. The granule of SlGV were ovoidal shape with an approximate measure of 240-340 nm×140-180 nm, and each granule contained one single rod-shape virion with a mean size of 180-200 nm×20-40 nm. Whereas, the polyhedra of SlNPV were irregular in shape with a approximate diameter of 1.0-1.5 ㎛, and numerous virions comprised of the multinucleocapsid were contained in each polyhedra. The major component of occlusion bodies produced by SlGV and SlNPV were about 29 and 30 kDa, respectively. When the phylogenic relationship between these viruses were analyzed using the nucleotide sequences of granulin gene from SlGV and polyhedrin gene from SlNPV, they were not closely related to each other. We also found that the two viruses showed similar insecticidal activity against 2nd instar larvae of Spodotera litura in terms of dose-response, but SlGV showed much longer LT50 than that of SlNPV. The two baculoviruses might be cooperatively be applied as biological control agent for the control of S. litura
Autographa californica nucleopolyhedrovirus (AcMNPV) has a large doublestrand DNA genome of approximately 134 kbp and harbors 156 open reading frames (ORFs). To elucidate DNA replication cascade of AcMNPV, we developed a novel baculovirus genome that can be maintained in Escherichia coli as a plasmid and can infect susceptible lepidopteran insect cells. This genome, named bAc-MK, contains a mini-F replicon and a kanamycin resistance marker. Using a convenient Tn7 transposon-based system, pPCS-S, 55 single ORF-truncated mutants were generated by random insertion into bAc-MK genome. These single ORF-truncated mutants were independently transfected into Sf9 cells, 16 of them were found affecting viral replication since they defected in producing polyhedra. Furthermore, to verify the pathogenicity of the single ORF-truncated mutants, the remaining 39 mutants were subjected to bioassay to Spodoptera exigua 3rd instar larvae. Among them, ac9-, ac49-, ac103- and ac105-knockout mutants showed higher mortality compared to that of bAc-MK. These results suggested that these ORFs could be related to pathogenicity of AcMNPV.
Entomopathogenic fungi are widely available as biological control agents for controlling insect pests in agriculture and forestry. The fungal culture broth contains various pathogenesis-related components such as blastospores, mycelium and insecticidal enzymes such as chitinase, Pr1- and Pr2-proteases, which have been reported to play an important role in penetrating insect cuticles. In this study, we tried to evaluate the utility of culture broth from Beauveria bassiana SFB-205 to control lepidopteran pests. High level of insecticidal activity correspond to over 90% of mortality were observed when the culture broth of B. bassiana SFB-205 was inoculated to the Spodoptera litura larvae together with the B. thuringiensis K1. The freeze-dried culture broth showed synergistic effects in insecticidal activity against larvae of S. exigua and S. litura when treated with corresponding baculoviruses, SeNPV and SlNPV. Active ingredient of the B. bassiana SFB-205 culture broth was identified to chitinase, which have truncated form by insertional mutation compared to previously reported chitinases.
Baculovirus chitinase gene (ChiA) is a late gene and is essential for liquefying host insect at the late stage of infection for its hydrolyzing chitin function. In previous report, baculovirus ChiA can offer many interseting new opportunities for pest control. Recently, a putative chitinase gene (ChiA) was identified in the Spodopter litura nucleopolyhedorvirus (SlMNPV-K1) genome. The open reading frame (ORF) contains 1,692 nucelotides (nt) and encodes a protein of 563 amino acids (aa) with a predicted molecular weight of 62.62 kDa. To conform the insecticidal activity of ChiA from SlMNPV-K1, we constructed a baculovirus transfer vector, pBac-SlChiA, and this transfer vector was co-transfected with the bApGOZA DNA into sf9 cell to generate corresponding recombinant viru which designed Ap-SlChiA. Western blot analysis indicate that SlMNPV-K1 ChiA was successfully expressed. We found the chitinase activity of recombinant virus was enhanced 53% than wide type AcMNPV by chitinase assay, and the recombinant virus showed higher evidently insecticidal activity against 3rd instar larvae of Spodotera exigua than wide type AcMNPV (4.5 time). These results suggested that the chitinase gene from SlMNPV-K1 could be successfully applied to improve pathogenicity of bauclovirus
Autographa californica nucleopolyhedrovirus (AcMNPV) has a large doublestrand DNA genome of approximately 134 kbp and comprises 156 open reading frames (ORFs). To elucidate DNA replication cascade of AcMNPV, we developed a novel baculovirus genome that can be maintained in Escherichia coli as a plasmid and can infect susceptible lepidopteran insect cells. This genome, named bAc-MK, contains a mini-F replicon and a kanamycin resistance marker. Using a convenient Tn7 transposon-based system, pPCS-S, which contains an ampicillin resistance gene, 56 single ORF-truncated mutants were generated by random insertion into bAc-MK genome. These single ORF-truncated mutants were independently transfected into Sf9 cells to verify viral replication. Interestingly, both lef-1 and p48 knockout mutants showed normal viral replication in infected cells, which are reported to essential for viral replication. These results suggest that these single ORF-truncated mutants are useful for elucidation of viral replication cascade.
Through an application of plasmid capture system (PCS) to Bacillus thuringiensis plasmid DNAs, we acquired 21 polymorphic clones of putative genomic DNA of bacteriophage. The genome size of phage 1-3 (PhBT1-3) was determined to be 46,517 base pairs (bp) with 35.43% G + C content and 83% coding region. Sixty-five putative open reading frames (ORFs) with more than 50 codons were found in the new phage genome. In accordance with this genome finding, the phage particles and its DNA were confirmed from the supernatant of B. thuringiensis 1-3. Morphological characterization and infectivity assay demonstrated that PhBT1-3 belongs to the family Siphoviridae and it showed infectivity to three B. thuringiensis type strains, galleriae, entomocidus, and morrisoni. Based on these results, we screened the existence of phages in B. thuringiensis type strains by PCR with terminase small subunit-specific primers. Ten of 67 type strains showed PCR products and the similarity of those putative amino acids was more than 70%. Furthermore, we verified the existence of various shaped phages from the supernatants of 10 B. thuringiensis type cultures. In conclusion, we characterized a putative genome of phage, PhBT1-3 from B. thuringiensis 1-3, and confirmed the distribution of phages in the group of 67 B. thuringiensis type strains.
This paper analyzes legal remedies for marine ecological damage as provided in Article 90, Section 2 of the Marine Environment Protection Law of the People’s Republic of China. In doing so, the paper examines the Tasman Sea Oil Spills Case, the first civil case in China to claim marine ecological damage involving foreign interests. The paper finds that many issues arise in practice due to the simplicity of the relevant legal provisions. The existing international treaties on marine oil pollution damage caused by ships do not cover marine ecological damage. However, domestic courts of some countries have relevant judicial practice on the matter. Hence, it is urgent to establish a set of new rules on marine ecological damage compensation in China and to specify the claimants, the scope for compensation and the measure of indemnity with the aim of providing an effective legal remedy for marine ecological damage.
Plasmid capture systems (PCS) facilitate cloning and manipulation of circular double-stranded DNA. We recently developed an improved PCS (PCS-LZ) to clone relatively large DNA molecules of 30-150 kb. The PCS-LZ donor consists of a mini-F replicon and a kanamycin resistance marker between Tn7 left and Tn7 right ends. Both the replicon and marker gene of the PCS-LZ donor are transferred into target plasmid DNAs by in vitro transposition, followed by replication in E. coli. Colonies are tested for lacZ expression by blue/white screening. Circular DNAs were obtained from plasmids of Bacillus thuringiensis, genome segments of Cotesia glomerata bracovirus and polymorphic genomes of Autographa californica nucleopolyhedrovirus. PCS-LZ is a powerful tool for use in genomic analysis and mutagenesis in invertebrate pathology, and we are extending its application to include vertebrate research.
Previously, we found that expression by translational fusion of the polyhedrin (Polh)-green fluorescence protein (GFP) led to the formation of granular structures and these fluorescent granules were easily precipitated by high-speed centrifugation. Here, we developed an easy, fast, and mass purification system using this baculovirus expression system (BES). An enhanced GFP (EGFP) fused with Polh gene at the N-terminus including an adaptor and enterokinase (EK) site between Polh and EGFP was expressed in Sf9 cells. The cells infected by AcPolhEKA-EGFP produced fluorescent granules. The EGFP fusion protein was purified from granule-containing cells according to three steps; cell harvest, sonication and EK digestion. Through the final enterokinase digestion, EGFP was presented mainly in the supernatant (93.3%) and the supernatant also showed a pure EGFP band. These results suggest that the combined procedure of Polh fusion expression and enterokinase digestion can used for the rapid and easy purification of other proteins.
Plasmid capture system (PCS) was developed for easy cloning and manipulation of circular double-stranded DNA from various sources. Recently, we improved PCS system (named PCS-LZ) to clone relatively large-sized DNA molecules (30-150 kb). PCS-LZ donor consists of a Mini-F replicon and a kanamycin resistance marker between Tn7L and Tn7R regions. Both replicon and marker gene of PCS-LZ donor are transferred into target plasmid DNAs by in vitro transposition and the transposed DNAs can replicate in E. coli cells by transformation. White/blue screening by LacZ expression is also available to avoid backgrounds. Up to now, we acquired various circular DNA clones from four sources such as plasmids of B. thuringiensis, bacteriophage genome isolated from B. thuringiensis, genome segments of Cotesia glomerata bracovirus, and polymorphic genomes of Autographa californica nucleopolyhedrovirus. Among them, interestingly, the genome clones of bacteriphage (Ph1-3) were screened from the PCS transposition with plasmids of B. thuringiensis 1-3 strain. The genome of Ph1-3 was fully sequenced (46517 bp) and open reading frames were analyzed. In accordance with this genome finding, the phage particles and its DNA were confirmed from the supernatant of B. thuringiensis 1-3. Ph1-3 showed infectivity to B. thuringiensis type strains such as subsp. galleriae, entomocidus, and morrisoni. Based on these results, we screened the existence of phage in B. thuringiensis type strains by PCR with terminase small subunit-specific primers. Ten of 67 type strains showed PCR products and their sequence similarity was more than 70%. Conclusively, we expect this PCS-LZ system would be a powerful tool for genomic analysis and mutagenesis study at the area of invertebrate pathology and further its application will be enlarged to the vertebrate pathology area.
To develop an advanced baculovirus insecticide with additional advantages, such as higher toxicity and recovering to wild-type baculovirus, a novel recombinant baculovirus, NeuroBactrus was constructed. Bacillus thuringiensis crystal protein gene (cry1-5) and an insect-specific neurotoxin gene (AaIT) were introduced into Autographa californica nucleopolyhedrovirus genome by fusion of polyhedrin-cry1-5-polyhedrin under the control of poyhedrin gene promoter, and by fusion of orf603 partial genes and AaIT under the control of early promoter of ORF3006 from Cotesia plutellae bracovirus. About 150 kDa of Polyhedrin-Cry1-5-Polyhedrin fusion protein expressed by NeuroBactrus was occluded into the polyhedra, and activated as about 65 kDa of crystal protein when treated with trypsin. RT-PCR analysis indicated that transcription of AaIT gene occurs by 2 h postinfection (p.i.) and increased at 16 h p.i.. NeuroBactrus showed high toxicity against Plutella xylostella larvae and significant reduction in median lethal time (LT50) against Spodoptera exigua larvae compared to those of wild-type AcNPV. Re-recombinants derived from NeuroBactrus, NBt-Del5 (deleted cry1-5), NBt-DelA (deleted AaIT) and NBt-Del5A (deleted cry1-5 and AaIT; wild-type baculovirus) were generated in serial passages in vitro. This result showed that the NeuroBactrus could be transferred to wild-type baculovirus along with serial passages by the homologous recombination between two polyhedrin genes and two partial orf603 genes.
The complete genomic nucleotide sequence of the Spodoptera litura multicapsid nucleopolyhedrovirus (SlMNPV) isolated in Korea, SlMNPV-K1, was determined. It was 137,435 bp long, with a 55.4 % A+T content and contained 132 putative open reading frames (ORFs) of 150 nucleotides or larger that showed minimal overlap. The 132 putative ORFs covered 87.7% of the genome. Among these, 131 ORFs were are homologous to genes identified in previously reported SlMNPV genome which consisted 139,342 bp and contained 141 putative ORFs. However, arrangement of some ORFs were somewhat different from each other. Even though the SlMNPV-K1 genome is smaller than that of previously reported SlMNPV genome and had lesser predicted ORFs, the main functional genes were all conserved. When the phylogenic relationship was analyzed using the nucleotide sequence of polyhedrin gene, SlMNPV-K1 was most closely related to Lymantria dispar multicapsid nucleopolyhedrovirus (LdMNPV) which were belonged to Group Ⅱ nucleopolyhedrovirus.
To develop an improved baculovirus insecticide with additional advantages, a novel recombinant baculovirus, AcB5B-AaIT was constructed. B. thuringiensis crystal protein gene (cry1-5) and insect-specific neurotoxin gene (AaIT) were introduced into Autographa californica nucleopolyhedrovirus genome by fusion of polyhedrin-cry1-5-polyhedrin under the control of polyhedrin (polh) gene promoter, and AaIT under the control of early promoter of ORF3004 from Cotesia plutellae bracovirus, respectively. About 150 kDa of Polyhedrin-Cry1-5-Polyhedrin fusion protein expressed by AcB5B-AaIT was occluded into the polyhedra produced by the recombinant virus, and activated as about 65 kDa of crystal protein when treated with gut-juice of Bombyx mori. The AcB5B-AaIT showed about 50% reduced LT50 value compared to that of the recombinant virus, Ap1Ac, expressing Cry1Ac against Plutella xylostella larvae. In addition, Spodoptera exigua larvae fed the recombinant polyhedra of AcB5B-AaIT showed about 4 fold higher refusing diet effect compared S. exigua larvae fed the recombinant polyhedra of the recombinant virus, Ap1C, expressing Cry1C. AcB5B-AaIT could be transferred to wild-type baculovirus along with serial passage by the homologous recombination between two polyhedrin genes contained in polh-cry1-5-polh fusion protein gene. These results suggested that the novel recombinant baculovirus, AcB5B-AaIT, could be applied as advanced viral insecticide.