Optimal Decision-Making of Closed-Loop Supply Chains in E-Commerce Platform Considering Sales Cooperations under Environmental Effects and WEEE Regulations.

Nowadays, to achieve carbon neutrality, e-commerce platforms participate in the sales and recycling of electrical and electronic products in consideration of waste electrical and electronic equipment (WEEE) regulations and environmental effects. This study builds a Stackelberg game model for an e-commerce closed-loop supply chain (ECLSC) under different sales cooperation modes between a manufacturer of electrical and electronic products and an e-commerce platform. Reverse induction is used to obtain the optimal decision-making and profit of the ECLSC under three sales cooperation modes, considering the influence of environmental effects on optimal decision and objective functions. The results show the following: the sales cooperation mode and environmental cost do not affect the WEEE recovery prices of manufacturers and e-commerce platforms, nor do they affect government subsidy standards for dismantling WEEEs; they are, however, positively correlated with environmental benefits. Furthermore, the wholesale and retail prices of electrical and electronic products under different sales cooperation modes are related to sales cooperation modes and environmental costs. Moreover, the processing fees imposed on the manufacturers are related to the environmental costs of the electrical and electronic products; the thresholds of environmental costs of products for government to levy processing fees are different under different sales cooperation modes. Finally, the environmental cost of products required by the government's levying of processing fees are the lowest under a hybrid model. Generally speaking, under WEEE regulations, governments should levy more processing fees for electrical and electronic products with higher environmental costs. Meanwhile, increased environmental benefits will always increase the profits of supply chain members, but increased environmental costs do not always reduce the profits of supply chain members, and multichannel product sales do not always generate profits for manufacturers.

Two Potential Syphilis Vaccine Candidates Inhibit Dissemination of Treponema pallidum.

Syphilis, caused by the spirochete Treponema pallidum subspecies pallidum, continues to be a major public health problem worldwide. Recent increases in the number of syphilis cases, in addition to the lack of an efficient vaccine against T. pallidum for humans, highlights an urgent need for the design and development of an efficacious syphilis vaccine. Here, we assess the vaccine potential of the adhesion protein Tp0136 and the outer membrane protein Tp0663. Rabbits were subcutaneously immunized with recombinant proteins Tp0136, Tp0663, or control PBS. Immunization with Tp0136 or Tp0663 generated a strong humoral immune response with high titers of IgG, as assessed by ELISA. Moreover, animals immunized with Tp0136 or Tp0663 exhibited attenuated lesion development, increased cellular infiltration at the lesion sites, and inhibition of treponemal dissemination to distant organs compared to the unimmunized animals. These findings indicate that Tp0136 and Tp0663 are promising syphilis vaccine candidates. Furthermore, these results provide novel and important information for not only understanding the pathogenic mechanisms of spirochetes, but also the development of spirochete-specific subunit vaccines.

Inter-Basin Water Transfer Supply Chain Coordination with Ramsey Pricing.

Often enough, social welfare and private benefit do not align for quasi-public goods/services. The inter-basin water transfer (IBWT) project provides a vivid example of this. In this paper, following the game-theoretical approach, we derive an optimal Ramsey pricing scheme to resolve these conflicts. We try to compare traditional supply chain management models with an optimal Ramsey pricing scheme, with an enforcement of coordination among firms. Using simulation techniques, we compute numerical estimates under three regimes: a standard equilibrium decision framework, a coordination decision model and a coordinated Ramsey pricing scheme. Our results show the relative welfare impact of different settings, revealing that the optimal pricing scheme based on the two-part tariff structure cannot only improve social welfare, but also ensure a target profit for participating firms. Lastly, our findings have strong policy implications for the government with profit regulation and the control of water resources.

The N-terminal D1 domain of Treponema pallidum flagellin binding to TLR5 is required but not sufficient in activation of TLR5.

Syphilis is a chronic bacterial infection caused by Treponema pallidum (T pallidum) and the pathogenesis that T pallidum infection induces immunopathological damages in skin and other tissues remains unclear. We have previously reported that recombinant flagellins of T pallidum can elicit IL-6 and IL-8 transcriptions via TLR5 pathway. To identify the domains which induced the pro-inflammatory activity and the importance of the interactions between TLR5 and domains, homology-based modelling and comparative structural analyses revealed that Tpflagellins can combine with TLR5 directly. Deletion mutations showed that the ND1 domain binding to TLR5 is required but not sufficient in TLR5 activation. Moreover, site-directed mutagenesis analysis indicated that the arginine residue (Tpflagellins R89) of the ND1 domain and its adjacent residues (Tpflagellins L93 and E113) constitute a hot spot that elicits IL-6, IL-8 transcriptions and TLR5 activation, and affects the binding of Tpflagellins to TLR5. Taken together, these results give insight into the pathogenesis of T pallidum and may contribute to the future design of Tpflagellins-based therapeutics and syphilis vaccine.

A recombinant multi-epitope peptide vaccine based on MOMP and CPSIT_p6 protein protects against Chlamydia psittaci lung infection.

Chlamydia psittaci is an obligate intracellular pathogen with a broad host range that can lead to severe infectious disease by transferring from birds to humans. Vaccination has been considered the best way to prevent chlamydial infection; nevertheless, there is currently still no commercially available vaccine that can inhibit the spread of C. psittaci. In previous study, major outer membrane protein (MOMP) of C. psittaci was confirmed to be an appropriate candidate antigen for limiting C. psittaci respiratory infections in a murine model, and plasmid-encoded CPSIT_p6 also has functions similar to those of MOMP in our study. Therefore, according to bioinformatics analysis, we developed a recombinant peptide containing multiple antigenic epitopes from MOMP (24-32, 262-272) and CPSIT_p6 protein (109-119, 173-181) and evaluated the efficacy of peptide immunization. BALB/c mice were inoculated intraperitoneally with the recombinant multi-epitope antigens three times at 2-week intervals and subsequently intranasally infected with C. psittaci. We found that the recombinant multi-epitope antigens induced strong humoral and Th1 cellular immune responses by producing meaningfully high levels of antigen-specific antibodies, interferon-gamma (IFN-γ), or interleukin-2 (IL-2). Vaccination significantly reduced the bacterial burden and the degree of inflammation in the infected lungs and led to lower levels of IFN-γ and IL-6. Furthermore, adoptive transfer of CD4+ splenocytes harvested from the vaccinated mice produced a significantly lower chlamydial load, indicating the importance of the cellular immune response. Therefore, the recombinant multi-epitope antigens may provide the basis for a new peptide-based vaccine against C. psittaci infection.

Immunogenicity and protective efficacy against Treponema pallidum in New Zealand rabbits immunized with plasmid DNA encoding flagellin.

Plasmid DNA encoding flagellin FlaB3 was used as a vaccination candidate for the evaluation of immunogenicity and protection against Treponema pallidum subsp. pallidum dissemination. First, intramuscular injection of the flagellin encoded by the plasmid DNA into New Zealand rabbits elicited both humoral and cellular immune responses. Total IgG production increased in response to flagellin. In addition, serum IFN-γ secretion and CD8+ cells were substantially greater in the rabbits immunized with the plasmid encoding flagellin FlaB3 than those in the rabbits immunized with recombinant flagellin. The flagellin encoded by the plasmid DNA induced significant upregulation of serum IL-6 and IL-8 compared to that of the control rabbits. Subsequently, intradermal challenge of the vaccinated New Zealand rabbits with 1 × 107T. pallidum resulted in a significant reduction of the bacterial organ burden in the blood, liver, spleen, and testicles in the flagellin plasmid DNA-vaccinated rabbits. Furthermore, the histopathological analysis demonstrated that the rabbits immunized with the plasmid DNA-encoded flagellin (FlaB3) showed better immune protection. These findings provide evidence that plasmid DNA-encoded flagellin (FlaB3) may be useful as a potential immunization route for future development of a vaccine to inhibit T. pallidum dissemination in related animals.

Screening and identification of immunoactive FlaB protein fragments of Treponema pallidum for the serodiagnosis of syphilis.

Flagellin is a classical pathogen-associated molecular pattern that can evoke a robust immune response. We have demonstrated previously that three full-length flagellins of Treponema pallidum, namely FlaB1, FlaB2 and FlaB3, did have diagnostic value in the serodiagnosis of syphilis. Here, we selected and constructed three recombinant fragments of each complete FlaB, both the conserved N-terminal and the C-terminal region, and the middle variable part, with the goal of exploring fragments unique to Treponema pallidum for use as antigen targets in a fragment-based serological test. The diagnostic performance of fragments was evaluated using different panels of serum specimens (= 332) by indirect IgG enzyme-linked immunosorbent assay. The data showed that all the conserved fragments exhibited excellent sensitivities (91.1-95.0%) but poor specificities (64.1-78.4%), while the three middle regions demonstrated higher sensitivities and specificities for detecting IgG antibody, with 92.7% and 96.1% for FlaB1M ('B1M'), 91.6% and 94.8% for B2M, and 95.0% and 100% for B3M, respectively. In comparison, the sensitivity and specificity of Architect Syphilis TP was found to be 95.5% and 94.8%, respectively. These findings revealed that the middle portion of each FlaB had epitopes specific for Treponema pallidum and identified B3M as a promising candidate antigen for the serodiagnosis of syphilis.

Treponema pallidum flagellins stimulate MMP-9 and MMP-13 expression via TLR5 and MAPK/NF-κB signaling pathways in human epidermal keratinocytes.

Syphilis is a chronic disease caused by Treponema pallidum and the pathogenesis is still unclear. T. pallidum infection induced inflammatory responses are involved in the immunopathological damage in skin and other tissues. Flagellin, the monomeric subunit of bacterial flagella, is a classic pathogen associated molecular patterns (PAMPs) that interacts to TLR5 and induces inflammatory responses. Keratinocytes, as immune sentinels recognize the PAMPs via TLRs, play an important role in skin innate immune response. Matrix metalloproteinases (MMPs) expressed by keratinocytes are involved in skin inflammatory responses and promoting pathogens invasion. In this study, we demonstrate that FlaB1, FlaB2 and FlaB3, the flagellins of T. pallidum, induced MMP-9 and MMP-13 production in human immortalized keratinocytes cell line HaCaT. Silencing of TLR5, but not TLR2 and TLR4 attenuated MMP-9 and MMP-13 expressions induced by T. pallidum flagellins. MMP-9 and MMP-13 expressions were also be abrogated by transfection with a dominant negative (DN) plasmid of MyD88. We also found that treatment of HaCaT cells with FlaB1, FlaB2 and FlaB3 activate the MAPK and NF-κB signaling pathways. Inhibited of ERK, JNK, p38 and NF-κB suppressed MMP-9 expression induced by the FlaB1. MMP-13 expression was found to be suppressed by pretreatment with inhibitors of ERK, JNK and NF-κB, but not p38. These findings demonstrate that T. pallidum flagellins (FlaB1, FlaB2 or FlaB3) can stimulate MMP-9 and MMP-13 expression through TLR5 and MAPK/NF-κB signaling pathways in human epidermal keratinocytes, which could contribute to the pathogenesis of T. pallidum infection.

Treponema pallidum flagellins elicit proinflammatory cytokines from human monocytes via TLR5 signaling pathway.

The tissue damage caused by syphilis infection may be associated with inflammation. However, the virulence factors of Treponema pallidum are still unclear, nor are the molecular mechanisms for leading to the productions of proinflammatory cytokines. Flagellin, a classic pathogen-associated molecular pattern (PAMP), is a potent immunogen that induces inflammation. In the present study, we have demonstrated that stimulations of human monocytes with Treponema pallidum FlaB1, FlaB2, and FlaB3 result in the up regulation of interleukin (IL)-6 and IL-8. Moreover, silencing of the Toll-like receptor 5 (TLR5) gene by using small interfering RNA was found to abrogate the T. pallidum flagellins-induced IL-6 and IL-8 expressions. Similarly, transfection with the dominant negative plasmid encoding MyD88 (pDeNy-hMyD88) was also giving rise to the down regulation of IL-6 and IL-8. We further investigated the relative contributions of mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) signaling to transcriptions and translations of IL-6 and IL-8. Western Blot and immuno fluorescence experiments revealed that flagellins-mediated IL-6 and IL-8 expressions are heavily dependent on ERK, p38, and NF-κB. In addition, inhibitions of p38 kinase, ERK, and NF-κB were found to attenuate the productions of IL-6 and IL-8. Taken together, our results indicate that T. pallidum flagellins can upregulate IL-6 and IL-8 generations via TLR5 and MAPK/NF-κB signaling pathways in THP-1 cells, which will improve our understanding of the pathogenesis of T. pallidum.