Identification of avian polyomavirus and its pathogenicity to SPF chickens

The research aimed to study an Avian polyomavirus strain that was isolated in Shandong, China. To study the pathogenicity of APV in SPF chickens, and provide references for epidemiological research and disease prevention and control of APV. The genetic characterization of APV strain (termed APV-20) was analyzed and the pathogenicity of APV was investigated from two aspects: different age SPF chickens, and different infection doses. The results revealed that the APV-20 exhibits a nucleotide homology of 99% with the other three APV strains, and the evolution of APV In China was slow. In addition, the APV-20 infection in chickens caused depression, drowsiness, clustering, and fluffy feathers, but no deaths occurred in the infected chickens. The main manifestations of necropsy, and Hematoxylin and Eosin staining (HE) showed that one-day-old SPF chickens were the most susceptible, and there was a positive correlation between viral load and infection dose in the same tissue. This study showed that SPF chickens were susceptible to APV, and an experimental animal model was established. This study can provide a reference for the pathogenic mechanism of immune prevention and control of APV

Optimal partial regularity of discontinuous subelliptic systems with VMO coefficients related to Hörmander’s vector fields

Abstract In this paper, we study discontinuous subelliptic systems with VMO coefficients related to Hörmander’s vector fields. In the case of growth exponential p ≥ 2 $p\geq 2$  , the regularity results of the partial Hölder continuity of weak solutions are established based on the  A $\mathcal{A}$ -harmonic approximation method under the controllable growth condition

Hydroelastic analysis of slamming induced impact on stiff and flexible structures by two-way CFD-FEA coupling

Publisher Copyright: © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.In rough seas, ships may be subject to wave-induced slamming loads.Thus, modelling of fluid and structural mechanics, and their dynamic interactions can help with the evaluation of fluid actions and the prediction ofwave-induced loads for use in ship design. In this paper a partitioned two-way coupled CFD-FEA fluid–structure interaction (FSI) method is usedto study the water entry of flat plates with different impact velocities and wedges with different deadrise angles. Results show that when flexibleplate dynamics prevail, at relatively low to medium impact velocity a negative correlation between the nondimensional pressure and water entryvelocities is evident near plate centre areas. A steady correlation exists when only stiff plate dynamics prevail. Pressure differences between stiffand flexible wedges become evident at small deadrise angles. The similarity of the pressure distribution during water impingement of ideally stiffwedge structures is not valid when structural flexibility prevails.Peer reviewe

In situ observation on the failure behavior of ZrO2-resin-dentin bonding interface with prefabricated indentation defects

Interfacial cracking and fracture of restorative materials are major obstacles to realize effective dental restoration. Especially, the bonding failure of compound interfaces consisting of dentin, resin and zirconium dioxide (ZrO _2 ) ceramic, exhibit complexity, variability and unpredictability due to the complicated loading type and oral environment. By using a self-developed miniaturized horizontal device integrating with thermostatic artificial saliva, an approximate oral environment was established to investigate the failure mechanism of ZrO _2 -resin-dentin compound interfaces. Through real-time in situ observation of shearing deformation behaviors of the dentin-resin and resin-ZrO _2 interfaces, the continuous propagation processes of cracks nucleating from the interfacial intersection line or dentin’s interior were analyzed in detail. The discontinuous cracking behaviors revealed the prior crack of resin-ZrO _2 interface, which attributed to the acid etching of dentin and significant gradients in Young’s modulus and hardness compared with the corresponding parameters of dentin-resin interface. The significant interfacial differences in mechanical properties promoted the crack nucleation and induced the bonding failure. A widest crack with a width of 1.4 μ m inside the dentin was also observed from the fractured ZrO _2 -resin-dentin specimen. This paper focused on the discontinuous interfacial cracking behaviors and bonding failure mechanisms of ZrO _2 -resin-dentin specimen, which would be beneficial to the research of novel composite resins and the improvement of bonding processes

A Multifunctional Light-Driven Swimming Soft Robot for Various Application Scenarios

The locomotor behavior of creatures in nature can bring a lot of inspiration for the fabrication of soft actuators. In this paper, we fabricated a bionic light-driven swimming soft robot that can perform grasping of tiny objects and achieve the task of object transfer. By adding carbon nanotubes (CNTs), the temperature-sensitive hydrogels can be endowed with light-responsive properties. The fabricated composite hydrogel structure can control the contraction and expansion of volume by light, which is similar to the contraction and diastole behavior of muscles. The oscillation of the fish tail and the grasping action of the normally closed micromanipulator can be achieved by the control of the irradiation of the xenon light source. The bending of the bionic arm can be controlled by the irradiation of a near-infrared (NIR) laser, which transforms the spatial position and posture of the micromanipulator. The proposed scheme is feasible for miniaturized fabrication and application of flexible actuators. This work provides some important insights for the study of light-driven microrobots and light-driven flexible actuators

A study into the FSI modelling of flat plate water entry and related uncertainties

This paper presents systematic comparisons of experiments against fluid structure interaction (FSI) simulations for flat water plate entry. Special focus is attributed on hydroelasticity and air trapping effects, quantification of the experimental and numerical uncertainties and the validity of modelling assumptions for the prediction of bottom slamming induced loads. Consequently, the American society of Mechanical Engineers standard for Verification and Validation is used to estimate the errors. Numerical and experimental results agree favourably. It is shown that pressures and strains may be prone to spatial effects that lead to minor deviations between experiments and simulations. High frequency vibration modes and model boundary conditions may also influence the results.Peer reviewe

Aspterpenacids A and B, Two Sesterterpenoids from a Mangrove Endophytic Fungus Aspergillus terreus H010

Two new sesterterpenoids, aspterpenacids A (<b>1</b>) and B (<b>2</b>), with an unusual carbon skeleton of a 5/3/7/6/5 ring system were isolated from the mangrove endophytic fungus Aspergillus terreus H010. Their structures were elucidated on the basis of spectroscopic methods, single-crystal X-ray diffraction analysis, and electronic circular dichroism calculations. A biogenetic pathway for <b>1</b> and <b>2</b> is proposed. Both <b>1</b> and <b>2</b> showed no significant antibacterial activity or cytotoxicity at 50 μM

Aspterpenacids A and B, Two Sesterterpenoids from a Mangrove Endophytic Fungus Aspergillus terreus H010

Two new sesterterpenoids, aspterpenacids A (<b>1</b>) and B (<b>2</b>), with an unusual carbon skeleton of a 5/3/7/6/5 ring system were isolated from the mangrove endophytic fungus Aspergillus terreus H010. Their structures were elucidated on the basis of spectroscopic methods, single-crystal X-ray diffraction analysis, and electronic circular dichroism calculations. A biogenetic pathway for <b>1</b> and <b>2</b> is proposed. Both <b>1</b> and <b>2</b> showed no significant antibacterial activity or cytotoxicity at 50 μM