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It is a significant technical challenge to exploit deep-sea polymetallic nodules with high efficiency and low disturbance. The mechanical behavior of seabed nodule collecting is very complicated, which is a multi-physical coupling process involving three-dimensional turbulent flow, discrete particle movement, and fine particle soil failure. In this paper, three main deep-sea hydraulic nodule collecting methods, i.e., the suck-up-based method, the Coandă-effect-based method, and the double-jet hydraulic method, are investigated by numerical simulation on the performance of nodule collecting and environmental disturbance. The realizable K-Epsilon two-layer model and the discrete element method are used to simulate the turbulent flow of the liquid phase and nodule particles in the solid phase respectively. The effect of collection flow qm and drag velocity v on collection rate η, turbulent kinetic energy k, and volume fraction φ of the seawater-sediment mixture in the collecting flow field is analyzed. The flow velocity, pressure, and nodule distribution are explored. The results indicate that, at the same qm and v, the double-jet hydraulic model will achieve the largest η, while the suck-up-based model will achieve the least η. The double-jet hydraulic model has the most significant disturbance to the near-bottom flow field and the most obvious sediment spreading phenomenon. In contrast, the suck-up-based model and the Coandăeffect-based model have less environmental disturbance, which is more conducive to the requirements of environmental protection. The Coandă-effect-based model shows minor sensitivity to qm and v and a good balance between high nodule collecting efficiency and low environmental disturbance. This paper will provide a scie.pngic basis for revealing the nodule collecting mechanism and designing and developing a nodule collecting device.

Wave impact is a strongly nonlinear interaction between waves and structures, and its load usually has the characteristics of a large peak value and short duration. In recent years, the extreme environment has frequently led to severe wave impacts on marine structures, resulting in loss of life and property, thus making the issue of wave impact become a great concern. For the complicated impact process, the theoretical analysis and model experiments can only provide simplified analytical solution and limited information on the slamming flow field. Therefore, numerical simulation has gradually become an effective means to study the issue of wave impact. Scholars at home and abroad have conducted a large number of numerical investigations on the load characteristics of wave impact, impact process, and its influencing factors on marine structures, gaining numerous important research conclusions. In this paper, the current progress, existing methods, and important conclusions of the numerical study of wave impact on marine structures are reviewed, which can provide useful references for further research on the numerical simulation of wave impact.

Novel methods of inverse reconstruction of environmental loads and virtual model test for hybrid model test are proposed. The environmental loads are extracted from the physical truncated model test, considering the nonlinear effects such as coupling effect among the six-degrees-of-freedom (6 DOF) motions and wave slamming, and viscous force of the fluid. The loads can be further applied to the numerical model in virtual wave basin to conduct virtual model test with truncated and full-depth mooring system. Wave basin tests under combined wave, wind, and current condition are conducted to validate the proposed methods, and the results show that the environmental loads can be accurately reconstructed from the physical model tests.

Wave run-up and air-gap are key issues for the safety of semi-submersible platforms. Real-time wave run-up prediction is helpful to ensure the safety of offshore activities. Based on the long short-term memory (LSTM) network, the extreme short term online prediction method is developed for predicting the wave run-up of semi-submersible platforms using wave and motion sequences. With the help of large sets of data from the model test, the LSTM model is trained and tested. The study shows that when the forecast durations are 6 s and 12 s, the average accuracy of the prediction results are 92.90% and 84.09%, and the relative errors of the maximum wave run-up height are lower than or equal to 19.69% and 30.66%, respectively. In addition, the model has a stable and exact prediction of extreme values of wave run-up height when the forecast duration is within 6 s, which confirms its ability to provide valid technical support for the early warning of wave slamming and overtopping during the operation of offshore platforms.

Hypertension is a common disease; however, it is more prevalent in older adults, and its prevalence is increasing in younger populations. Numerous studies have revealed that hypertension and the composition and functionality of the intestinal flora are closely correlated. The balance of the intestinal flora, intestinal barrier integrity, and metabolite content of the intestinal flora play significant roles in the occurrence and progression of hypertension. Therefore, we performed a comprehensive review of Traditional Chinese medicine (TCM) for hypertension, focusing on the role of the intestinal flora to understand the mechanism by which TCM regulates hypertension through its effects on the intestinal flora. We analyzed the findings using the terms "traditional Chinese medicine," "hypertension," "high blood pressure," "blood pressure," "intestinal flora," "intestinal barrier function," "intestinal flora metabolites," and other keywords from the China National Knowledge Infrastructure, VIP Chinese Science and Technology, Wanfang Data, PubMed, and ScienceDirect databases. We found that TCM treats hypertension by regulating the balance of the intestinal microbiota, increasing the abundance of beneficial bacteria, reducing the abundance of harmful bacteria, improving intestinal barrier function, increasing compact proteins, reducing intestinal permeability, and regulating the content of intestinal flora metabolites. The use of TCM to treat hypertension by regulating the intestinal flora is a promising therapeutic strategy. However, most studies are limited by small sample sizes and there is a lack of large-scale randomized controlled trials. In the future, multi-center controlled clinical trials are needed to verify the efficacy and safety of TCM, optimize therapeutic protocols, and establish a foundation for the standardized and personalized application of TCM in hypertension management. [ABSTRACT FROM AUTHOR]

As a critical disease usually infected by Staphylococcus aureus, with a worldwide effect on dairy animals, subclinical mastitis is characterized by persistence and treatment resistance. During mastitis, the blood–milk barrier (BMB)'s integrity is impaired, resulting in pathogen invasion and milk quality decline. In this study, it was found that ginsenoside Rg1 (Rg1), a natural anti-inflammatory and antioxidant compound derived from ginseng, inhibited the onset of tight junction (TJ) dysfunction and ameliorated lipoteichoic acid (LTA)-induced BMB disruption inside and outside the organisms. According to subsequent mechanistic studies, Rg1 inhibited excessive autophagy and inactivated the NLRP3 inflammasome by blockading ROS generation, thereby alleviating TJ dysfunction. Peroxisome proliferator-activated receptor gamma (PPARγ) was identified as a potential target of Rg1 by means of molecular docking plus network pharmacology analysis. Furthermore, it was demonstrated that Rg1 inhibited the oxidative stress levels by activating PPARγ, and regulating the upstream autophagy-related AMPK/mTOR signaling pathway, thus decreasing excessive in vivo and in vitro autophagy. The ROS/autophagy/NLRP3 inflammasome axis was identified as a promising target for treating subclinical bovine mastitis in this study. In conclusion, Rg1 is proven to alleviate BMB disruption by activating PPARγ to inhibit oxidative stress and subsequent excessive autophagy in the case of subclinical bovine mastitis. [ABSTRACT FROM AUTHOR]

In order to study the characteristics of vortex-induced motion and galloping of the classic Spar platform, a model test with a mooring system is conducted in basin. The sway motion characteristics of the Spar platform at different current velocities are analyzed. By comparing the results in currents, waves, and wave-current coupled conditions, the coupling effects of current and wave on vortex-induced motion and galloping of the Spar platform are also studied. The results show that galloping is induced by the currents with high reduced velocities. Compared with the vortex-induced motion, the galloping phenomenon has a longer period, larger amplitude, and randomness. The coupling of current and wave would not change the mode of flow-induced motion, but it significantly affects the motion amplitude.

Simple Summary: Endometritis in dairy cows refers to a process of local inflammatory reaction in the endometrium due to microbial invasion of the damaged endometrium. The aim of this study was to determine the therapeutic effect of ginsenoside Rg1 on the endometritis-induced fibrosis process. The experimental data from this study indicate that ginsenoside Rg1 is able to alleviate the epithelial–mesenchymal transition (EMT) process induced by the lipopolysaccharides (LPS) of bovine endometrial epithelial cell line (BEND) cells, which is related to the inhibition of ginsenoside Rg1 on reactive oxygen species (ROS) accumulation, thereby restraining NLRP3 inflammatory factors from expression. Experiments on mice showed that ginsenoside Rg1 alleviates endometrial fibrosis in mice. The aforementioned results can serve as powerful preclinical evidence for the potential of ginsenoside Rg1 to become an alternative drug for curing endometrial fibrosis. Abnormal function and the fibrosis of endometrium caused by endometritis in cows may lead to difficult embryo implantation and uterine cavity adhesions. Emerging evidence indicates that ginsenoside Rg1 can effectively resist inflammation and pathological fibrosis in different organs. It is hypothesized that ginsenoside Rg1 may possess the potential to mitigate endometrial fibrosis induced by lipopolysaccharides (LPS) in dairy cows. Herein, a model of LPS-stimulated fibrosis was constructed using bovine endometrial epithelial cell line (BEND) cells and ICR mice. Western blotting was used to detect the protein level, and reactive oxygen species (ROS) content was measured by means of DCFH-DA. The uterine tissue structure was stained with H&E and Masson staining. The murine endometrium was assessed for oxidative stress by detecting the concentration of MDA together with the activity of enzymatic antioxidants SOD and CAT. Ginsenoside Rg1 interfered with NLRP3 activation by reducing ROS generation. After the application of ROS inhibitor NAC and NLRP3 inhibitor MCC950, ginsenoside Rg1 could interfere in the ROS/NLRP3 inflammasome signaling pathway by suppressing the epithelial–mesenchymal transition (EMT) of BEND cells. Our in vivo data showed that ginsenoside Rg1 relieved endometrial fibrosis of the mouse model of LPS-induced endometritis by restraining the ROS/NLRP3 inflammasome signaling pathway. Ginsenoside Rg1 inhibits LPS-induced EMT progression in BEND cells probably by inhibiting the activation of ROS-NLRP3 inflammasome. [ABSTRACT FROM AUTHOR]