Cross-Protective Shigella Whole-Cell Vaccine With a Truncated O-Polysaccharide Chain

Shigella is a highly prevalent bacterium causing acute diarrhea and dysentery in developing countries. Shigella infections are treated with antibiotics but Shigellae are increasingly resistant to these drugs. Vaccination can be a countermeasure against emerging antibiotic-resistant shigellosis. Because of the structural variability in Shigellae O-antigen polysaccharides (Oag), cross-protective Shigella vaccines cannot be derived from single serotype-specific Oag. We created an attenuated Shigella flexneri 2a strain with one rather than multiple Oag units by disrupting the Oag polymerase gene (Δwzy), which broadened protective immunogenicity by exposing conserved surface proteins. Inactivated Δwzy mutant cells combined with Escherichia coli double mutant LT(R192G/L211A) as adjuvant, induced potent antibody responses to outer membrane protein PSSP-1, and type III secretion system proteins IpaB and IpaC. Intranasal immunization with the vaccine preparation elicited cross-protective immunity against S. flexneri 2a, S. flexneri 3a, S. flexneri 6, and Shigella sonnei in a mouse pneumonia model. Thus, S. flexneri 2a Δwzy represents a promising candidate strain for a universal Shigella vaccine

Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza

The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections

Liquid crystallinity driven highly aligned large graphene oxide composites

Graphene is an emerging graphitic carbon materials, consisting of sp2 hybridized two dimensinal honeycomb structure. It has been widely studied to incorporate graphene with polymer to utilize unique property of graphene and reinforce electrical, mechanical and thermal property of polymer. In composite materials, orientation control of graphene significantly influences the property of composite. Until now, a few method has been developed for orientation control of graphene within polymer matrix. Here, we demonstrate facile fabrication of high aligned large graphene oxide (LGO) composites in polydimethylsiloxane (PDMS) matrix exploiting liquid crystallinity. Liquid crystalline aqueous dispersion of LGO is parallel oriented within flat confinement geometry. Freeze-drying of the aligned LGO dispersion and subsequent infiltration with PDMS produce highly aligned LGO/PDMS composites. Owing to the large shape anisotropy of LGO, liquid crystalline alignment occurred at low concentration of 2 mg/ml in aqueous dispersion, which leads to the 0.2 wt% LGO loaded composites1771sciescopu

Metropolitan water purification facilities towards variability mitigation of the renewable resources: Optimal bid method for small hydropower generators

As carbon neutrality in the power system arises as one of the important issues, numerous nations have been increasing penetration of the renewable resources. However, greater penetration of the renewable resources in the power systems has caused reliability issues due to the innate unpredictable output characteristics. For minimization of unpredictability and its consequential effects on the system reliability, the nations such as the Republic of Korea, Great Britain and Australia have been introduced market-based variability mitigating measures. The incentive policy driven market-based measures were designed to draw voluntary participation from the asset owners capable of providing controllability over the resources aggregated to be a single portfolio. Small hydropower generators in metropolitan water purification facilities can be actively utilized for such mitigation because of their relatively stable output characteristics. However, entities responsible for metropolitan water purification facilities with small hydropower generators have been reluctant to participate in the market with the mitigations incentive since there are no structured methods to acquire dispatch reliability of the water resources considering participation in the energy market. Thus, this paper presents a scheduling algorithm for the aggregated portfolio of renewable resources, utilizing small hydropower generators as one of the tools for variability mitigation. In the results, the portfolio-wide forecast error was reduced to below 2% in the presence of the scheduling algorithm and small hydropower generators as mitigation resources, while the water intake schedule at water purification facilities remained evenly distributed. Small hydropower generators played a key role in mitigating variability in the algorithm, and the revenue generated from the participation of these small hydropower generators contributed to approximately one third of the gross revenue from the portfolio. The algorithm was demonstrated to provide renewable resource owners with an additional revenue stream, beyond what is typically provided by government subsidies

Production of novel FeOOH/reduced graphene oxide hybrids and their performance as oxygen reduction reaction catalysts

Fe-based hybrid systems have been suggested as promising candidates for oxygen reduction reaction (ORR) catalysts owing to their good catalytic performances and feasibilities for mass production at low cost. In this work, we develop means of producing novel hybrids containing FeOOH particles well-dispersed on graphene-based materials using a one-pot solution process. The hybrid materials show good electrochemical catalytic activity for ORR, such as, an on-set potential of 0.76 V (vs. the reversible hydrogen electrode), a near four electron pathway, and excellent stability against methanol poisoning during durability test. This is the first report of the use of FeOOH/reduced graphene oxide hybrid materials as ORR catalysts.close1