The seahorse relies on the undulatory motion of the dorsal fin to generate thrust, which makes it possess quite high maneuverability and efficiency, and due to its low volume of the dorsal fin, it is conducive to the study of miniaturization of the driving mechanism. This paper carried out a study on the undulatory motion mechanism of the seahorse’s dorsal fin and proposed a dynamic model of the interaction between the seahorse’s dorsal fin and seawater based on the hydrodynamic properties of seawater and the theory of fluid-structure coupling. A simulation model was established using the Fluent software, and the 3D fluid dynamic mesh was used to study the undulatory motion mechanism of the seahorse’s dorsal fin. The effect of the swing frequency, amplitude, and wavelength of the seahorse’s dorsal fin on its propulsion performance was studied. On this basis, an optimized design method was used to design a bionic seahorse’s dorsal fin undulatory motion mechanism. The paper has important guiding significance for the research and miniaturization of new underwater vehicles.

The predation behavior of the pistol shrimp is extremely special, and the predation process will produce a huge popping sound, which has caused extensive research by scholars from all over the world. This article carried out a study on the rapid closing jet mechanism of pistol shrimp’s claws. A theoretical model, based on the hydrodynamic characteristics of seawater and the theory of fluid-structure coupling, was proposed for the interaction between the claws and seawater. A simulation model was established using the finite volume software Fluent, and the rapid closing jet mechanism of pistol shrimp’s claws was verified by using fluid dynamic grid. This article studied the influence of different fluid models on the simulation results. The effects of the claws’ closing angular velocity and angular acceleration on the interaction between the claws and seawater were analyzed, which provides a theoretical basis for the development of new underwater kinetic energy weapons.

To obtain the resources of the moon, humans have launched a series of exploration activities on the moon, and the landing buffer device is an indispensable device on the lander required to perform lunar surface exploration missions. It can effectively protect the lander during landing scientific payloads such as instruments on the lander. Based on the mechanical properties and deformation mechanism of the aluminum honeycomb as buffer material, this paper compares and analyzes different simulation schemes and finally establishes the bonding model of the honeycomb by using the discrete element method; the parameters of the honeycomb material are matched through compression experiments to verify the discrete element honeycomb simulation and the feasibility of the scheme and its parameters. To meet the buffering requirements of large landers, a spider web honeycomb structure is proposed, its modeling method is studied by using the discrete element secondary development program, and the model is compressed as a whole to verify the energy consumption characteristics of the spider web honeycomb structure. Aiming at the honeycomb buffer device during the landing process, the cobweb honeycomb buffer structure and its corresponding landing coupling model were established using the discrete element method, the landing process was simulated and analyzed, and the landing results were predicted to verify the feasibility of the device, providing a reference for the design of the lander and its buffer device.

The subjects of this study were 80 patients who underwent mixed hemorrhoids surgery in our hospital from January to October 2020 (mixed hemorrhoids external and internal ligation, internal hemorrhoids ligation or Xiaozhiling injection) and developed anal edge edema after surgery. According to the order of hospitalization, the patients were randomly divided into treatment group and control group, with 40 cases each. In the control group, blank hot pack was applied on the basis of anorectal No. 1 lotion for prevention and treatment of anal edge edema after operation; in the treatment group, hot pack of Traditional Chinese medicine was applied on the basis of anorectal No. 1 lotion for prevention and treatment of anal edge edema. The course of treatment was 7 days. The edema subsidence and postoperative pain scores were observed in both groups. Results: The scores of anal edema and pain in the treatment group were significantly lower than those in the control group (P < 0.05), and the significant efficiency and total effective rate in the treatment group were significantly better than those in the control group, with statistical difference (P < 0.05). Conclusion: Chinese medicine hot election package is effective in treating postoperative anal edema of mixed hemorrhoids, and the method is simple and suitable for clinical promotion.

Elevated reactive oxygen species (ROS) induce oxidative damage in retinal pigment epithelium (RPE) and contribute to the development of age-related macular degeneration (AMD). Gastrodin plays an antioxidant role in distinct diseases, such as epilepsy, cerebral ischemia, Alzheimer’s disease, and cardiovascular diseases. However, the function of gastrodin in AMD remains unclear. Human RPE (ARPE-19) cells were incubated with 300 μM hydrogen peroxide (H2O2) for 24 hours. The results showed that H2O2 decreased cell viability and promoted the cell apoptosis of ARPE-19 cells. H2O2-induced ARPE-19 cells were then treated with different concentrations of gastrodin. Gastrodin increased cell viability of H2O2-induced ARPE-19 cells, suppressed the cell apoptosis of H2O2-induced ARPE-19 cells with reduced B-cell lymphoma (Bcl)-2 like protein (Bax), and enhanced Bcl-2. The levels of ROS were enhanced, malondialdehyde (MDA) was up-regulated, and superoxide dismutase (SOD) and glutathione (GSH) were down-regulated in H2O2-induced ARPE-19 cells. However, gastrodin reduced the levels of ROS and MDA and elevated SOD and GSH in H2O2-induced ARPE-19 cells. Furthermore, H2O2-induced increase of inducible nitric oxide synthase (iNOS) and p-p38 proteins in ARPE-19 was reversed by gastrodin. In conclusion, gastrodin exerted antiapoptotic and antioxidant capacities to protect against H2O2-induced oxidative stress in RPE, thereby acting as a potential agent for managing AMD.