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ObjectiveThe induced electromagnetic properties brought forth by disturbed seawater cutting the geomagnetic field can provide important information for non-acoustic detection technologies. In view of the complex and highly nonlinear interaction between the flow field and electromagnetic field of a high-speed submarine, it is necessary to deeply analyze the influence of the turbulence structure caused by natural cavitation on the induced electromagnetic field.MethodsFirst, a multi-physical field mathematical model of fluid-electromagnetic coupling is established on the basis of hydrodynamics and electromagnetics. Next, the intensity and range of near-field electromagnetic signatures in the cavitation evolution, and the time-frequency characteristics of the induced electric field under different cavitation numbers, are obtained through numerical simulation using Fluent software.ResultsThe simulation results demonstrate that the electromagnetic field shows obvious quasi-periodic unsteady fluctuation features due to the evolution of the cavitation morphology. The magnitudes of the induced electric field and magnetic field are 10−1 mV/m and 10−2 nT respectively, which are within the detection range of the most sophisticated sensors. Additionally, the cavitation number is highly correlated with the time-frequency characteristics of the induced electric field. When the cavitation number decreases from 0.4 to 0.2, the fluctuation intensity of the induced electric field is significantly enhanced, its main frequency decreases from 49.94 Hz to 34.19 Hz, and the low-frequency fluctuation component increases accordingly.ConclusionThe induced electromagnetic characteristics of submarines can be employed to guide the non-acoustic detection of underwater moving bodies, and the main frequency range of the induced electric field can provide references for the electromagnetic communication frequency selection of high-speed submarines.

To adapt to the extreme conditions of plateau environments, yaks have evolved thick hair, making them an ideal model for investigating the mechanisms involved in hair growth. We can gain valuable insights into how hair follicles develop and their cyclic growth in challenging environments by studying yaks. However, the lack of essential data on yak hair follicle histology and the absence of in vitro cell models for hair follicles serve as a limitation to such research objectives. In this study, we investigated the structure of skin tissue during different hair follicle cycles using the yak model. Additionally, we successfully established in vitro models of hair follicle-associated cells derived from yak skin, including dermal papilla cells (DPCs), preadipocytes, and fibroblasts. We optimized the microdissection technique for DPCs culture by simplifying the procedure and reducing the time required. Furthermore, we improved the methodology used to differentiate yak preadipocytes into mature adipocytes, thus increasing the differentiation efficiency. The introduction of yak as a natural model provides valuable research resources for exploring the mechanisms of hair growth and contributes to a deeper understanding of hair follicle biology and the development of regenerative medicine strategies.

Hsp70 and Hsp90 play an important role in testis development and spermatogenesis regulation, but the exact connection between Hsp70 and Hsp90 and metabolic stress in cattle is unclear. Here, we focused on the male cattle–yak and yak, investigated the expression and localization of Hsp70 and Hsp90 in their tissues, and explored the influence of these factors on development and metabolism. In our study, a total of 54 cattle (24 cattle–yaks and 30 yaks; aged 1 day to 10 years) were examined. The Hsp90 mRNA of the cattle–yak was first cloned and compared with that of the yak, and variation in the amino acid sequence was found, which led to differences in protein spatial structure. Using real-time quantitative PCR (RT-qPCR) and Western blot (WB) techniques, we investigated whether the expression of Hsp70 and Hsp90 mRNA and protein are different in the cattle–yak and yak. We found a disparity in Hsp70 and Hsp90 mRNA and protein expression in different non-reproductive organs and in testicular tissues at different stages of development, while high expression was observed in the testes of both juveniles and adults. Moreover, it was intriguing to observe that Hsp70 expression was significantly high in the yak, whereas Hsp90 was high in the cattle–yak (p < 0.01). We also examined the location of Hsp70 and Hsp90 in the testis by immunohistochemical (IHC) and immunofluorescence (IF) techniques, and the results showed that Hsp70 and Hsp90 were positive in the epithelial cells, spermatogenic cells, and mesenchymal cells. In summary, our study proved that Hsp70 and Hsp90 expressions were different in different tissues (kidney, heart, cerebellum, liver, lung, spleen, and testis), and Hsp90 expression was high in the testis of the cattle–yak, suggesting that dysplasia of the cattle–yak may correlate with an over-metabolism of Hsp90.