Chemical investigation of the cultures of marine Streptomyces sp. 182SMLY led to the discovery of two new polycyclic anthraquinones, which were elucidated as N-acetyl-N-demethylmayamycin (1) and streptoanthraquinone A (2) based on the extensive spectroscopic analysis including 2D NMR, HRESIMS, and an electronic circular dichroism (ECD) calculation. Both anthraquinones remarkably suppressed the proliferation of four different glioma cell lines with IC₅₀ values in a range from 0.5 to 7.3 μM and induced apoptosis in the glioma cells. The ratios of IC₅₀ for normal human astrocytes to IC₅₀ for glioma cells were 6.4–53 for 1 and >14–31 for 2. N-acetyl-N-demethylmayamycin (1) also inhibited the growth of methicillin-resistant Staphylococcus aureus with MIC 20.0 μM.

Autonomous Underwater Vehicles (AUVs) are the mainstream equipment for underwater scientific research and engineering. However, it remains a great challenge for AUVs to carry out near-seabed operations because of their poor maneuverability. In this paper, a new design for a high-maneuverability disc-shaped AUV is proposed, namely, the Autonomous Underwater Helicopter (AUH). We designed the AUH’s propulsion system through dynamic analysis based on the unique disc shape. The experimental prototype was built by mechatronics technology, after which several motion experiments were carried out to demonstrate the high maneuverability. We find that the prototype has high maneuverability: it can cruise at 0.8 m/s (about 1.5 knots), at least; its turning radius is zero and its turning speed is at least 20 deg/s; and the motion of specific curves in a small range was completed. It is demonstrated that over-actuation is not necessary for the high-maneuverability AUH because of its unique disc shape. A propulsion system consisting of four propellers and a buoyancy adjustment system is used for the highly maneuverable AUH. In addition, the AUH may be a solution for near-seafloor operations.

Large vertical metal tanks are the primary vessels for the storage and turnover of crude oil, and the accuracy of their capacity calibrations are of great significance. The optical reference line method (ORLM) is used for capacity calibration and is time-consuming, labor-intensive, and hazardous, because of the elevated work. This paper aims to present a robot to overcome the problems above. We propose a tracked wall-climbing robot (TWCR) with permanent magnetic adhesion tracks, a collapsible scale, and an optional shovel-like rust remover that enable the TWCR to move stably on tank surfaces and perform the ORLM. Two sets of field tests (internal ORLM and external ORLM) indicate that capacity calibration by the TWCR is time saving, convenient, and safe, in addition to being accurate and reliable.

Autonomous Underwater Helicopter (AUH) is a disk-shaped Autonomous Underwater Vehicle (AUV), and it has comparative advantage of near-bottom hovering and whole-direction turn-around ability over the traditional slender AUV. An optimization design of its irregular geometric profile is essential to improve its hydrodynamic performance. A parametric representation of its profile is proposed in this paper using Non-Uniform Rational B-spline (NURBS) curve. The parametric representation of AUH profile is described with two decision variables and several data points. Based on this parametric curve, Computational Fluid Dynamics (CFD) simulation is carried out to evaluate its hydrodynamic performance with various parameters. A predication model is established over variables’ design space using Kriging surrogate model with CFD simulation results and a Genetic Algorithm (GA) procedure is conducted to find optimal design variables, which can produce an optimum lift-drag ratio. CFD verification results confirm that AUH profile with optimized design variables can increase its lift-drag ratio by 2.11 times compared with that of non-optimized ones. It demonstrates that the parametric representation and optimization procedure of AUH profile proposed in this paper is feasible, and it has a great potential in improving AUH’s performance.