Molecular Characterization and Geographic Distribution of a Mymonavirus in the Population of Botrytis cinerea

Here, we characterized a negative single-stranded (−ss)RNA mycovirus, Botrytis cinerea mymonavirus 1 (BcMyV1), isolated from the phytopathogenic fungus Botrytis cinerea. The genome of BcMyV1 is 7863 nt in length, possessing three open reading frames (ORF1–3). The ORF1 encodes a large polypeptide containing a conserved mononegaviral RNA-dependent RNA polymerase (RdRp) domain showing homology to the protein L of mymonaviruses, whereas the possible functions of the remaining two ORFs are still unknown. The internal cDNA sequence (10-7829) of BcMyV1 was 97.9% identical to the full-length cDNA sequence of Sclerotinia sclerotiorum negative stranded RNA virus 7 (SsNSRV7), a virus-like contig obtained from Sclerotinia sclerotiorum metatranscriptomes, indicating BcMyV1 should be a strain of SsNSRV7. Phylogenetic analysis based on RdRp domains showed that BcMyV1 was clustered with the viruses in the family Mymonaviridae, suggesting it is a member of Mymonaviridae. BcMyV1 may be widely distributed in regions where B. cinerea occurs in China and even over the world, although it infected only 0.8% of tested B. cinerea strains

Shape Sensing for Continuum Robots by Capturing Passive Tendon Displacements With Image Sensors

Continuum robots and soft robots have shown great potential in industrial and medical applications. Sensing the shapes of continuum robots is a challenging but significant problem for enhancing their performance during various tasks. In this letter, we present a novel method to estimate the shapes of continuum robots by capturing passive tendon displacements with image sensors. This method is reliable but low-cost. To reconstruct the shape of the continuum robot, an intuitive way based on screw theory and the material frame is also presented. The displacements of passive tendons are related to the integral of the geometric parameters of the continuum robot. By using passive tendon displacements, not only bending but also twisting of the robot can be calculated. The experiments show that our method can estimate the shapes of the robot deformed in different conditions. The mean distal position error is 3.01% of the length and the mean shape error is 1.86% of the length. The mean distal direction error is 4.1 degrees. Besides, sensing the shapes of continuum robots in real-time is also achieved

Selective Laser Melting of 60NiTi Alloy with Superior Wear Resistance

In this work, the selective laser melting (SLM) 60NiTi alloy was successfully fabricated. Through designing an orthogonal experiment of parameters optimization including laser power (P) and scanning speed (v), the optimal parameters window with both high forming quality and appropriate composition proportion was established. The SLM 60NiTi can exhibit high relative density (>98%) and low Ni loss (3. The optimally-selected SLM 60NiTi exhibits a high compression strength of 2.2 GPa and large reversible strain of 7% due to the reversible stress-induced martensitic transformation of the NiTi phase and the large elastic strain of the Ni4Ti3 phase. It also exhibits superior wear resistance to conventional casting solution treated 60NiTi because the NiTi phase formed in an SLM repeated thermal cycle possesses a lower solution Ni atom and thus lower critical stress for martensitic transformation, and is more prone to undergo martensitic transformation upon friction and wear

Two Novel Hypovirulence-Associated Mycoviruses in the Phytopathogenic Fungus Botrytis cinerea: Molecular Characterization and Suppression of Infection Cushion Formation

Botrytis cinerea is a necrotrophic fungus causing disease on many important agricultural crops. Two novel mycoviruses, namely Botrytis cinerea hypovirus 1 (BcHV1) and Botrytis cinerea fusarivirus 1 (BcFV1), were fully sequenced. The genome of BcHV1 is 10,214 nt long excluding a poly-A tail and possesses one large open reading frame (ORF) encoding a polyprotein possessing several conserved domains including RNA-dependent RNA polymerase (RdRp), showing homology to hypovirus-encoded polyproteins. Phylogenetic analysis indicated that BcHV1 may belong to the proposed genus Betahypovirus in the viral family Hypoviridae. The genome of BcFV1 is 8411 nt in length excluding the poly A tail and theoretically processes two major ORFs, namely ORF1 and ORF2. The larger ORF1 encoded polypeptide contains protein domains of an RdRp and a viral helicase, whereas the function of smaller ORF2 remains unknown. The BcFV1 was phylogenetically clustered with other fusariviruses forming an independent branch, indicating BcFV1 was a member in Fusariviridae. Both BcHV1 and BcFV1 were capable of being transmitted horizontally through hyphal anastomosis. Infection by BcHV1 alone caused attenuated virulence without affecting mycelial growth, significantly inhibited infection cushion (IC) formation, and altered expression of several IC-formation-associated genes. However, wound inoculation could fully rescue the virulence phenotype of the BcHV1 infected isolate. These results indicate the BcHV1-associated hypovirulence is caused by the viral influence on IC-formation-associated pathways

Selective laser melted high Ni content TiNi alloy with superior superelasticity and hardwearing

TiNi alloys with high content Ni (52-55 at.%) are perfectly suitable for preparing wear-and corrosion resistant parts that service on the space station, spacecraft, and submarine, because of their superior superelasticity, high strength, and hardwearing. However, the fabrication of complicated Ni-rich TiNi parts by the traditional machining method often faces problems of poor precision, low efficiency, and high cost. In this work, we succeed in preparing an excellent Ti47Ni53 alloy by selective laser melting (SLM), and thus, open a new way for the efficient and precise formation of complicated Ni-rich TiNi parts with superelasticity and hardwearing. An optimized processing window for compact parts without defects is reported. The elaborately fabricated Ti47Ni53 alloy exhibited a breaking strain of 11%, a breaking stress of 2.0 GPa, a superelastic strain of 9%, and a better hardwearing than that of casting and quenched Ti47Ni53 alloy. Besides, the microstructure, phase transformation, and deformation, as well as their influence mechanisms are investigated by in situ transmission electron microscope (TEM) and high-energy X-ray diffraction (HE-XRD). The results obtained are of significance for both fundamental research and technological applications of SLM-fabricated high Ni content TiNi alloys. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology