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Aiming at the problems of low accuracy and high loss rate when the traditional target tracking (TT) method is applied to the TT of the moving operation of the transmission line, a transmission line based on an inspection robot and edge computing (EC) is proposed: the mobile job TT method. First, the basic framework of the TT algorithm is proposed, relying on the edge device to develop the TT system for mobile operations on the transmission line. Video information is collected by an intelligent inspection robot and sent to the target tracking system in the edge device for processing to obtain accurate data. Then, the gradient disappearance and explosion problems caused by the increase of network depth are solved by using the deep residual network. The traditional deep residual network is improved by introducing the improved bidirectional feature reinforcement network and the classification and regression subnet. The loss of position texture information is remedied, and the accurate tracking of the moving target on transmission line is realized. Finally, the real-time data acquisition of mobile operation target is realized by using an intelligent inspection robot, and the experimental verification is conducted. The proposed algorithm is compared and analyzed against the three other algorithms using the same data set through simulation experiments. The results show the precision, recall rate, accuracy, and comprehensive evaluation index F1 value of the proposed algorithm rank highest, reaching 93.8%, 90.2%, 83.8%, and 89.8%, respectively, compared with the other algorithms.

ABSTRACTStreptococcus pneumoniaeis an infectious pathogen mainly infecting host bodies through the respiratory system. An effective pneumococcal vaccine would be targeted to the mucosa and provide not only protection against invasive infection but also against colonization in the respiratory system. In the present work, we applied bacterium-like particles (BLPs) as an adjuvant for the development of a PspA mucosal vaccine, in which the PspA protein was displayed on the surface of BLPs. Intranasal immunization with the PspA-BLP pneumococcal vaccine, comprised of PspA2 from pneumococcal family 1 and PspA4 from pneumococcal family 2, not only induced a high level of serum IgG antibodies but also a high level of mucosal SIgA antibodies. Analysis of binding of serum antibodies to intact bacteria showed a broad coverage of binding to pneumococcal strains expressing PspA from clade 1 to 5. Immunization with the PspA-BLP vaccine conferred protection against fatal intranasal challenge with both PspA family 1 and family 2 pneumococcal strains regardless of serotype. Therefore, the PspA-BLP pneumococcal vaccine was demonstrated to be a promising strategy for mucosal immunization to enhance both systemic and mucosal immune responses.

Enterovirus 71(EV71) has caused severe epidemics of hand, foot and mouth disease (HFMD) in the Asia Pacific in recent years, particularly in infants and pre-school children. It has become a serious public health threat, as currently there are no approved vaccines or antiviral drugs for EV71 infection. Many EV71 vaccines have been under development worldwide, however the main focus is inactivated EV71 vaccines. For example, the inactivated EV71 vaccine has recently finished phase III clinical trial in Mainland China. There have been very few studies on EV71 virus like particles (VLPs). In this study, the immunogenicity and protective potency of the EV71 VLPs produced in insect cells were evaluated in mice with different dosages. Our results showed that EV71 VLPs could elicit high titers of neutralizing antibodies (NTAbs) in a dose-dependent manner and NTAbs were sustained after the second injection with an average GMT (geometric mean titer) level from 19 to 2960 in immunized mice. Survival rates were 100%, 100%, 85%, and 40% after challenge with 15 LD50(median lethal dose) of EV71 in these newborn mice, respectively. ED50(50% effective dose) of VLPs was 0.20 μg/dose in newborn mice, while NTAb titer under this dosage was about 50. Passive protection was determined with 2 methods and demonstrated that the survival rates were positively correlated with NTAb titers, which at 24 and 54 induced 50% survival rates in experimental animals. The ED50of VLP vaccines and the passive NTAb titers were also analyzed. The maternal NTAb titer was similar as the passive NTAb titer in the mouse model challenged with our lethal mouse EV71 strain. Hence, our work has provided preliminary data on the protection potency of VLPs as a vaccine candidate and would facilitate future VLP vaccine development.

Here is reported a novel pneumolysin(Ply) mutant(PlyM2) that addresses a long-standing problem for vaccine development in this field: detoxification of Ply in the premise of retaining antigenic integrity. Structure and function of wild-type Ply(PlyWT) and PlyM2 mutants were detected and compared. Their structures were not significantly different according to the analysis by thermal-dependent fluorescence spectroscopy and circular dichroism spectroscopy. PlyM2 was confirmed to have lost hemolytic activity and yet could induce neutralizing antibodies to prevent in vitrohemolysis by PlyWT and S. Pneumoniae. These results give support to PlyM2 to be a new protein antigen for inclusion in the development of an effective pneumococcal multiprotein vaccine.

Enterovirus71 (EV71) and CoxsackievirusA16 (CVA16) have caused severe epidemics of hand, foot and mouth disease (HFMD) in the Asia Pacific in recent years, particularly in infants and young children. This disease has become a serious public health problem, as no vaccines or antiviral drugs have been approved for EV71 and CA16 infections. In this study, we compared four monovalent vaccines, including formalin-inactivated EV71 virus (iEV71), EV71 virus-like particles (VLPs) (vEV71), formalin-inactivated CVA16 virus (iCVA16) and CVA16 VLPs (vCVA16), along with two bivalent vaccines, including equivalent doses of formalin-inactivated EV71+CVA16 virus (iEV71+iCVA16) and EV71+CVA16 VLPs (vEV71+vCVA16). The IgG titers and neutralization antibodies titers demonstrated that there are no immune interference exists between the two immunogens of EV71 and CVA16. IgG subclass isotyping revealed that IgG1 and IgG2b were induced primarily in all vaccine groups. Furthermore, cross-neutralization antibodies were elicited in mouse sera against other sub-genotypes of EV71 and CVA16. In vivo challenge experiments showed that the immune sera from vaccinated animals could confer passive protection to newborn mice against lethal challenge with 14 LD50of EV71 and 50 LD50of CVA16. Our results indicated that bivalent vaccination is promising for HFMD vaccine development. With the advantage of having a better safety profile than inactivated virus vaccines, VLPs should be used to combine both EV71 and CVA16 antigens as a candidate vaccine for prevention of HFMD virus transmission.

Two new cyclic pentapeptides (1and 2) and the known blazein (3), ganodesterone (4), ergosterin (5), cerevisterol (6), 24-methylcholesta-4,6,8(14),22-tetraen-3-one (7), 5,8-epidioxyergosta-6,22-dien-3-ol (8), 16-α-d-mannopyranosyloxyisopimar-7-en-19-oic acid (9), and 16-hydroxy isopimar-7-en-19-oic acid (10) have been isolated from the crude extract of an endolichenic Xylariasp. The structures of 1and 2were elucidated primarily by NMR and MS methods. The absolute configurations of 1and 2were assigned using Marfey’s method on their acid hydrolysate. Compounds 1−10were evaluated for activity against fungi and for synergistic antifungal activity. Compound 1showed synergistic antifungal activity against Candida albicansSC5314 with 0.004 μg/mL ketoconazole.

ABSTRACTStreptococcus pneumoniaeis a major cause of invasive pneumococcal disease, septicemia, and meningitis that can result in high morbidity rates in children under 5 years old. The current polysaccharide-based vaccines can provide type-specific immunity, but a broad-spectrum vaccine would provide greater coverage. Therefore, developing pneumococcal-protein-based vaccines that can extend to more serum types is highly important. In this study, we vaccinated mice via the subcutaneous (s.c.) route with a systemic vaccine that is a mixture of fusion protein PsaA-PspA23 and a single protein, PspA4, with aluminum hydroxide as an adjuvant. As a comparison, mice were immunized intranasally with a mucosal vaccine that is a mixture of PspA2-PA-BLP (where PA is protein anchor and BLP is bacterium-like particle) and PspA4-PA-BLP, via the intranasal (i.n.) route. The two immunization processes were followed by challenge with Streptococcus pneumoniaebacteria from two different PspA families. Specific IgG titers in the serum and specific IgA titers in the mucosa were determined following immunizations. Bacterial loads and survival rates after challenge were compared. Both the systemic vaccine and the mucosal vaccine induced a significant increase of IgG against PspAs. Only the mucosal vaccine also induced specific IgA in the mucosa. The two vaccines provided protection, but each vaccine showed an advantage. The systemic vaccine induced higher levels of serum antibodies, whereas the mucosal vaccine limited the bacterial load in the lung and blood. Therefore, coimmunizations with the two types of vaccines may be implemented in the future.