Enhancing Robotic-Based Propeller Blade Sharpening Efficiency with a Laser-Vision Sensor and a Force Compliance Mechanism.

The edge sharpness of a propeller blade plays a vital role in improving energy transmission efficiency and reducing the power required to propel the vehicle. However, producing finely sharpened edges through casting is challenging due to the risk of breakage. Additionally, the blade profile of the wax model can deform during drying, making it difficult to achieve the required edge thickness. To automate the sharpening process, we propose an intelligent system consisting of a six-DoF industrial robot and a laser-vision sensor. The system improves machining accuracy through an iterative grinding compensation strategy that eliminates material residuals based on profile data from the vision sensor. An indigenously designed compliance mechanism is employed to enhance the performance of robotic grinding which is actively controlled by an electronic proportional pressure regulator to adjust the contact force and position between the workpiece and abrasive belt. The system's reliability and functionality are validated using three different workpiece models of four-blade propellers, achieving accurate and efficient machining within the required thickness tolerances. The proposed system provides a promising solution for finely sharpened propeller blade edges, addressing challenges associated with the earlier robotic-based grinding studies.

A Balance of Yki/Sd Activator and E2F1/Sd Repressor Complexes Controls Cell Survival and Affects Organ Size.

The Hippo/Yki and RB/E2F pathways both regulate tissue growth by affecting cell proliferation and survival, but interactions between these parallel control systems are poorly defined. In this study, we demonstrate that interaction between Drosophila E2F1 and Sd disrupts Yki/Sd complex formation and thereby suppresses Yki target gene expression. RBF modifies these effects by reducing E2F1/Sd interaction. This regulation has significant effects on apoptosis, organ size, and progenitor cell proliferation. Using a combination of DamID-seq and RNA-seq, we identified a set of Yki targets that play a diversity of roles during development and are suppressed by E2F1. Further, we found that human E2F1 competes with YAP for TEAD1 binding, affecting YAP activity, indicating that this mode of cross-regulation is conserved. In sum, our study uncovers a previously unknown mechanism in which RBF and E2F1 modify Hippo signaling responses to modulate apoptosis, organ growth, and homeostasis.

DENR-MCT-1 promotes translation re-initiation downstream of uORFs to control tissue growth.

During cap-dependent eukaryotic translation initiation, ribosomes scan messenger RNA from the 5' end to the first AUG start codon with favourable sequence context. For many mRNAs this AUG belongs to a short upstream open reading frame (uORF), and translation of the main downstream ORF requires re-initiation, an incompletely understood process. Re-initiation is thought to involve the same factors as standard initiation. It is unknown whether any factors specifically affect translation re-initiation without affecting standard cap-dependent translation. Here we uncover the non-canonical initiation factors density regulated protein (DENR) and multiple copies in T-cell lymphoma-1 (MCT-1; also called MCTS1 in humans) as the first selective regulators of eukaryotic re-initiation. mRNAs containing upstream ORFs with strong Kozak sequences selectively require DENR-MCT-1 for their proper translation, yielding a novel class of mRNAs that can be co-regulated and that is enriched for regulatory proteins such as oncogenic kinases. Collectively, our data reveal that cells have a previously unappreciated translational control system with a key role in supporting proliferation and tissue growth.

Spectroscopic characterization of metal bound phytochelatin analogue (Glu-Cys)4-Gly.

The metal ion binding properties of a phytochelatin (PC) analogue, (Glu-Cys)4-Gly (named as EC4), have been studied by a divalent metal ion binding assay monitored by UV-visible spectroscopy, circular dichroism and NMR spectroscopy. Spectro- photometric titration with different divalent metal ions have revealed that the stiochoimetry of metal-bound EC4 was 1:1, and its metal binding affinities with different divalent metal ions in the order of Cd(II)>Cu(II)>Zn(II)>Pb(II)>Ni(II)>Co(II). UV-visible spectroscopic analysis of metal complexes indicated that four sulfur atoms in cysteine residues are attributable to ligand-to-metal charge transfer (LMCT) between divalent metal ions and EC4, and further confirmed by 1D H1 NMR study and Circular Dichroism. In addition, Circular Dichroism spectra of both free and metal-bound forms of EC4 revealed that metal coordination drives the nonapeptide chain to fold into a turned conformation. The comprehensive analysis of spectroscopic properties of the nonapeptide complexed with metal ions not only provides a fundamental description of the metal ion binding properties of PC analogue, but also shows a correlation between metal binding affinity of PC analogue and the induction activity of metal ions.