Bioinspired Jumping Soft Actuators of the Liquid Crystal Elastomer Enabled by Photo-Mechanical Coupling.

Jumping, a fundamental survival behavior observed in organisms, serves as a vital mechanism for adapting to the surrounding environment and overcoming significant obstacles within a given terrain. Here, we present a light-controlled soft jumping actuator inspired by asphondylia, which employs a closed-loop structure and utilizes a liquid crystal elastomer (LCE). Photo-mechanical coupling highlights the significant influence of the light source on the actuator's jumping behavior. Manipulating the light intensity, the relative position of stimulus and light lock, and the concentration of disperse red 1 (DR1) allows precise control over both the maximum take-off velocity and jump height. Furthermore, tailoring the size of the LCE actuator offers a means of regulating jumping behavior. Upon exposure to 460 nm LED irradiation, our actuator achieves remarkable performance, with a maximum jumping height of 10 body length (BL) and take-off velocity of 62 BL/s. These actuators accumulate and rapidly release energy, enabling the effective transportation of microcargos across substantial distances. Our research yields valuable insights into the realm of soft robotics, underscoring the pivotal importance of photo-mechanical coupling in the field of soft robotics, thereby serving as a catalyst for inspiring continued exploration of agile and capable systems by prestoring elastic energy.

Identification and characterization of a virus-specific continuous B-cell epitope on the PrM/M protein of Japanese Encephalitis Virus: potential application in the detection of antibodies to distinguish Japanese Encephalitis Virus infection from West Nile Virus and Dengue Virus infections.

BACKGROUND: Differential diagnose of Japanese encephalitis virus (JEV) infection from other flavivirus especially West Nile virus (WNV) and Dengue virus (DV) infection was greatly hindered for the serological cross-reactive. Virus specific epitopes could benefit for developing JEV specific antibodies detection methods. To identify the JEV specific epitopes, we fully mapped and characterized the continuous B-cell epitope of the PrM/M protein of JEV. RESULTS: To map the epitopes on the PrM/M protein, we designed a set of 20 partially overlapping fragments spanning the whole PrM, fused them with GST, and expressed them in an expression vector. Linear epitope M14 (105VNKKEAWLDSTKATRY120) was detected by enzyme-linked immunosorbent assay (ELISA). By removing amino acid residues individually from the carboxy and amino terminal of peptide M14, we confirmed that the minimal unit of the linear epitope of PrM/M was M14-13 (108KEAWLDSTKAT118). This epitope was highly conserved across different JEV strains. Moreover, this epitope did not cross-react with WNV-positive and DENV-positive sera. CONCLUSION: Epitope M14-13 was a JEV specific lineal B-cell epitpe. The results may provide a useful basis for the development of epitope-based virus specific diagnostic clinical techniques.

Newcastle disease virus-based MERS-CoV candidate vaccine elicits high-level and lasting neutralizing antibodies in Bactrian camels.

Middle East respiratory syndrome coronavirus (MERS-CoV), a member of the Coronaviridae family, is the causative pathogen for MERS that is characterized by high fever, pneumonia, acute respiratory distress syndrome (ARDS), as well as extrapulmonary manifestations. Currently, there are no approved treatment regimens or vaccines for MERS. Here, we generated recombinant nonvirulent Newcastle disease virus (NDV) LaSota strain expressing MERS-CoV S protein (designated as rLa-MERS-S), and evaluated its immunogenicity in mice and Bactrian camels. The results revealed that rLa-MERS-S showed similar growth properties to those of LaSota in embryonated chicken eggs, while animal immunization studies showed that rLa-MERS-S induced MERS-CoV neutralizing antibodies in mice and camels. Our findings suggest that recombinant rLa-MERS-S may be a potential MERS-CoV veterinary vaccine candidate for camels and other animals affected by MERS.

[Rescue of a recombinant Newcastle disease virus expressing the green fluorescent protein].

A recombinant Newcastle disease virus (NDV) expressing the green fluorescent protein (GFP) was generated by applying reverse genetics techniques. The GFP open reading frame flanked by NDV transcription start and stop sequences was inserted between the phosphoprotein (P) and matrix protein (M) in a full-length cDNA clone of NDV Lasota vaccine strain. This plasmid transcribing antigenome RNA was cotransfected with helper plasmids expressing viral nucleoprotein, phosphoprotein and large protein into cells stably expressing T7 RNA polymerase. The rescued virus was first propagated in 10-day-old embryonated eggs and the allantoic fluid was used to infect primary chicken embryo fibroblasts (CEF) cells. The appearance of GFP in live infected cells confirmed further the recovery of a recombinant NDV (rNDV-GFP) expressing this reporter gene. Nine successive passages in embryonated chicken eggs were performed. Allantoic fluid samples were then titrated by a microtiter plate HA test. HA positive ailantoic fluid were used for further egg passages. All the allantoic fluid samples were titrated by end point dilutions and infected cells were examined for the presence of GFP expression. To analyze virus growth, 10-day-old embryonated SPF chicken eggs were inoculated with 1 x 10(4) EID50 rNDV or rNDV-GFP. At 24,48,72 and 96 h p.i. the allantoic fluid of inoculated eggs containing live embryos was harvested and clarified by centrifugation. Supernatants were used for titration of EID50 in 10-day-old embryonated SPF chicken eggs. rNDV and rNDV-GFP grew to similar titers (10(9) EID50/mL). In order to test the virulence of rNDV-GFP, infectious allantoic fluid of rNDV-GFP were inoculated into embryonated SPF chicken eggs at 1 x 10(6) EID50. No dead embryonated egg was found within 96 hours. The replication kinetics and pathogenicity in SPF embryonated eggs of rNDV-GFP did not differ significantly from that of the parent virus. LaSota is a widely used NDV live vaccine strain. The reverse genetic system established for this LaSota vaccine strain provided a useful platform for development of novel live viral vector vaccines in future.