Oral Delivery of the Sj23LHD-GST Antigen by Salmonella typhimurium Type III Secretion System Protects against Schistosoma japonicum Infection in Mice

Schistosomiasis japonica is a zoonotic parasitic disease and occurs predominantly in Southeast Asia and China. Using a simple, cheap, yet efficient oral method to deliver the vaccine antigen would benefit to control its transmission in that the oral vaccine could be made into a preparation and mixed with feedstuffs of livestock hosts. In this study, we used an attenuated S. typhimurium strain VNP20009, whose safety has been demonstrated in phase I clinical trial, to express the bivalent Schistosoma japonicum antigen Sj23LHD-GST by an intracellular activated promoter (nirB) and deliver it to host cells through type III secretion system. After oral vaccination of this recombinant strain, efficient protection against S. japonicum challenge was induced in mice. Mean while, granuloma formation in the liver was improved significantly in the immunized mice. This protective immune response was Th1 specific type as evidenced by increase in the production of IL-12 and IFN-γ. This work provides an alternative S. japonicum vaccine for livestock and humans

Magnetic properties of X-C2N (X=Cl, Br and I) monolayers: A first-principles study

The electronic and magnetic properties of X-C2N (X=F, Cl, Br and I) monolayers have been systematically investigated from first-principles calculations. The F atom can be strongly adsorbed on the top of the host carbon atoms, while the Cl, Br and I atoms favor the top of the host nitrogen atoms of C2N monolayers. These functionalized X-C2N (X=F, Cl, Br and I) monolayers exhibit interesting electronic and magnetic features. The F-C2N monolayer system shows a nonmagnetic metallic state, while the X-C2N (X=Cl, Br and I) monolayer systems exhibit the magnetic semiconducting ground state. Moreover, the ferromagnetic state is energetically more stable configuration for the X-C2N (X=Cl, Br and I) monolayer systems. Magnetic analysis further elaborates that the induced magnetism in the X-C2N (X=Cl, Br and I) monolayer systems mainly arises from the local magnetic moments of the halogen adatoms. Thus, the chemical functionalization of nitrogenated honey graphene through halogen atoms adsorption has promising applications in electronic devices

Potential Risks of PM2.5-Bound Polycyclic Aromatic Hydrocarbons and Heavy Metals from Inland and Marine Directions for a Marine Background Site in North China

Ambient PM2.5-bound ions, OC, EC, heavy metals (HMs), 18 polycyclic aromatic hydrocarbons (PAHs), 7 hopanes, and 29 n-alkanes were detected at Tuoji Island (TI), the only marine background atmospheric monitoring station in North China. The annual PM2.5 average concentration was 47 ± 31 μg m−3, and the average concentrations of the compositions in PM2.5 were higher in cold seasons than in warm seasons. The cancer and non-cancer risks of HMs and PAHs in cold seasons were also higher than in warm seasons. BaP, Ni, and As dominated the ∑HQ (hazard quotient) in cold seasons, while the non-carcinogenic risk in warm seasons was mainly dominated by Ni, Mn, and As. The ILCR (incremental lifetime cancer risk) values associated with Cr and As were higher in the cold season, while ILCR-Ni values were higher in the warm season. The backward trajectory was calculated to identify the potential directions of air mass at TI. Through the diagnostic ratios of organic and inorganic tracers, the sources of particulate matter in different directions were judged. It was found that ship emissions and sea salt were the main sources from marine directions, while coal combustion, vehicles emissions, industrial process, and secondary aerosols were the main source categories for inland directions. In addition, potential HM and PAH risks from inland and marine directions were explored. The non-cancerous effects of TI were mainly affected by inland transport, especially from the southeast, northwest, and west-northwest. The cancerous effects of TI were mainly simultaneously affected by the inland direction and marine direction of transport

Enhancement of protective efficacy through adenoviral vectored vaccine priming and protein boosting strategy encoding triosephosphate isomerase (SjTPI) against Schistosoma japonicum in mice.

Schistosomiasis japonica is a zoonotic parasitic disease; developing transmission blocking veterinary vaccines are urgently needed for the prevention and control of schistosomiasis in China. Heterologous prime-boost strategy, a novel vaccination approach, is more effective in enhancing vaccine efficacy against multiple pathogens. In the present study, we established a novel heterologous prime-boost vaccination strategy, the rAdV-SjTPI.opt intramuscular priming and rSjTPI subcutaneous boosting strategy, and evaluated its protective efficacy against Schistosoma japonicum in mice.Adenoviral vectored vaccine (rAdV-SjTPI.opt) and recombinant protein vaccine (rSjTPI) were prepared and used in different combinations as vaccines in a mouse model. The specific immune responses and protective efficacies were evaluated. Furthermore, the longevity of protective efficacy was also determined. Results showed that the rAdV-SjTPI.opt priming-rSjTPI boosting strategy elicited higher levels of specific IgG responses and broad-spectrum specific cellular immune responses. The protective efficacy could reach up to nearly 70% and 50% of protection could be observed at 10 weeks after the last immunization in mice.The rAdV-SjTPI.opt intramuscular priming-rSjTPI subcutaneous boosting vaccination strategy is a novel, highly efficient, and stable approach to developing vaccines against Schistosoma japonicum infections in China

Synergistically enhanced charge separation in BiFeO3/Sn:TiO2 nanorod photoanode via bulk and surface dual modifications

Charge separation is regarded as a vital factor determining the photoelectrochemical (PEC) performance of TiO2 photoanode. Herein, for the first time, the synergistic effect between Sn doping and ferroelectric BiFeO3 (BFO) coating in BFO/Sn:TiO2 composite photoanode for enhanced PEC performance is reported. The Sn doping leads to enhanced charge carrier density due to efficient charge separation. After the deposition of ferroelectric BFO thin film, the charge-separation efficiency (ηsep) is further enhanced because of spontaneous polarization of the BFO layer. More importantly, the PEC performance could be further improved by positive polarization of the BFO/Sn:TiO2 composite photoanode, achieving remarkable photocurrent density (Jph) of 1.76 mA cm−2 at 1.23 V vs. reversible hydrogen electrode and high stability. This work indicates that the dual modification (i.e. Sn doping in bulk and ferroelectric BFO thin film deposition on the surface) holds a great promise in improving the PEC performance of photoanodes by promoting charge separation, which can be extended to other common photoanode materials, such as Fe2O3 and BiVO4.Ministry of Education (MOE)The work was supported by the National Natural Science Foundation of China (41502030), the Natural Science Foundation of Hubei Province of China (2017CFB190), the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (CUG170638), and the Open Foundation of Engineering Research Center of Nano-Geomaterials of Ministry of Education (NGM2017KF002 and NGM2018KF017). This research is also supported by the Singapore Academic Research Fund (RG5/16, RG11/17 and RG114/17)

Key issues in the design and delivery of learning and teaching

<p>Data show the average OD values of each group with standard deviations at 1∶100 serum dilution. The serum samples were collected at 4 weeks after the 3^rd DNA immunization prior to challenge. Statistical differences are indicated by <i>p</i> values.</p

Spatial engineering of a Co(OH)ₓ encapsulated p-Cu₂S/n-BiVO₄ photoanode : simultaneously promoting charge separation and surface reaction kinetics in solar water splitting

The photoelectrochemical (PEC) water splitting efficiency of a photoanode is restricted by charge recombination and sluggish reaction kinetics. Here, we demonstrated the spatial engineering of an ultrathin Co(OH)ₓ encapsulated p-Cu₂S/n-BiVO₄ photoanode for simultaneously enhancing charge separation and surface reaction kinetics in solar water splitting. Specifically, the separation efficiency of photoexcited charge carriers in the bulk was effectively improved due to the formation of a p-Cu₂S/n-BiVO₄ heterojunction, and the light-driven water oxidation reaction on the surface was further promoted because of the introduction of Co(OH)ₓ as an oxygen evolution catalyst (OEC) layer. As a result, the p-Cu₂S/n-BiVO₄ heterostructure yielded a largely enhanced charge separation efficiency of up to 79%, and a significant surface charge separation of 70% was achieved, attributed to the deposition of the Co(OH)ₓ cocatalyst. Furthermore, this synergistic effect in the photoanode gave rise to a remarkably enhanced photocurrent density of 3.51 mA cm⁻² at 1.23 V vs. the reversible hydrogen electrode. This spatial engineering provides an efficient strategy for the simultaneous improvement of internal and surface charge separation via dual modification, i.e., p-n heterojunction formation and OEC coating.Ministry of Education (MOE)The work was supported by the National Natural Science Foundation of China (41502030), the Natural Science Foundation of Hubei Province of China (2017CFB190), the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (CUG170638), and the Open Foundation of Engineering Research Center of Nano-Geomaterials of Ministry of Education (NGM2017KF002 and NGM2018KF017). This research was also supported by the Singapore Academic Research Fund (RG5/16, RG11/17 and RG114/17)