PHYSICS OF FLUIDS
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2020
·Vol. 32
·期 8
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IF 3.514
Li Luncao,Liu Bing,Hao Hanlin,Li Longyang,Zeng Zhixiang
The drag is a crucial factor in reducing the speed of movement and increasing unnecessary energy loss. In this work, inspired by dolphins, five bionic flexible coatings with drag reduction performance were designed and manufactured. First and foremost, the mixed solution, composed of the polydimethylsiloxane and ethyl acetate, was sprayed on aluminum disks with a spray gun, and the bionic flexible coatings were obtained by heating the aluminum disks sprayed with the mixed solution. Afterward, the mechanical properties and surface characteristics of the flexible coatings were characterized. The experimental results for the flexible coatings of drag reduction performance were obtained by using the drag force device. Above all, the parametric study focusing on the flexible coating of the mechanical properties affects the station of flow, which is performed to analyze the impact on drag reduction. Selecting the aluminum disk without any coating as a reference, numerical simulation methods were introduced to explore the drag reduction mechanism of the bionic flexible coating. The results evidence that the drag reduction ratio is 21.6% at the rotation velocity 50 rpm. Under the action of frictional resistance, the coating of elastic deformation caused by the viscoelasticity of the coating like the dolphin skin results in a decrease in frictional resistance of the wall.
研究领域:
流体力学
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材料科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2023
·
IF 11.4
Xian Sun,Yanqing Xie,Xiyang Zhang,Jiebing Song,Yuping Wu
The potential risks of per- and polyfluoroalkyl substance (PFAS) accumulation in nearshore dolphins are not well understood. Here, transcriptional activities of 12 PFAS on peroxisome proliferator-activated receptors (PPAR-α, -β/δ, and -γ) in Indo-Pacific humpback dolphins (Sousa chinensis) were evaluated. All PFAS activated scPPAR-α in a dose-dependent manner. PFHpA exhibited the highest induction equivalency factors (IEFs). The order of IEFs for other PFAS was as follows: PFOA > PFNA > PFHxA > PFPeA > PFHxS > PFBA > PFOS > PFBuS ≈ PFDA ≫ PFUnDA and PFDoDA (not activated). The total induction equivalents (∑IEQs, 5537 ng/g wet weight) indicated that more attention should be paid to investigating contamination levels in dolphins, especially in PFOS (82.8% contribution to the ∑IEQs). The scPPAR-β/δ and -γ were not affected by any PFAS, except for PFOS, PFNA, and PFDA. Furthermore, PFNA and PFDA could induce higher PPAR-β/δ and PPAR-γ-mediated transcriptional activities than PFOA. Compared to human beings, PFAS might be more potent PPAR-α activators in humpback dolphins, suggesting that the dolphins may be more susceptible to the adverse effects of PFAS. Our results may be instructive for understanding the impacts of PFAS on marine mammal health due to the identical PPAR ligand-binding domain.
研究领域:
环境科学
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毒理学
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分子生物学
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DOI
PubMed
高影响因子
Biology-Basel
·
2025
·Vol. 14
·期 8
·986
·
IF 3.5
Yanjian Yang,Guanrong Zhang,Ruilong Xu,Yiyang Deng,Zequan Mo,Yanwei Li,Xueming Dan
Simple SummaryStreptococcus iniae(S. iniae) is a major aquaculture pathogen causing significant economic losses. While infections show seasonal patterns tied to water temperature, the mechanisms behind its thermal adaptation remain unclear. This study explored the proteomic changes inS. iniaeat different temperatures and their effects on immune responses in yellowfin seabream (Acanthopagrus latus,A. latus). Results demonstrated that elevated temperatures markedly upregulated bacterial virulence factor expression, resulting in significantly higher host mortality rates. Furthermore, thermal stress enhances the destruction of key immune functions of the host byS. iniae, including immune cell survival, ROS production, and phagocytic activity. These findings provide novel insights into the heat-regulated immune evasion strategies ofS. iniae, offering valuable theoretical foundations for developing temperature-aware disease management protocols in aquaculture systems.Streptococcus iniae(S. iniae) is a globally significant aquatic pathogen responsible for severe economic losses in aquaculture. While theS. iniaeinfection often exhibits distinct seasonal patterns strongly correlated with water temperature, there is limited knowledge regarding the temperature-dependent immune evasion strategies ofS. iniae. Our results demonstrated a striking temperature-dependent virulence phenotype, with significantly higherA. latusmortality rates observed at high temperature (HT, 33 °C) compared to low temperature (LT, 23 °C). Proteomic analysis revealed temperature-dependent upregulation of key virulence factors, including streptolysin S-related proteins (SagG, SagH), antioxidant-related proteins (SodA), and multiple capsular polysaccharide (cps) synthesis proteins (cpsD, cpsH, cpsL, cpsY). Flow cytometry analysis showed that HT infection significantly reduced the percentage of lymphocyte and myeloid cell populations in the head kidney leukocytes ofA. latus, which was associated with elevatedcaspase-3/7expression and increased apoptosis. In addition, HT infection significantly inhibited the release of reactive oxygen species (ROS) but not nitric oxide (NO) production. UsingS. iniaecps-deficient mutant, Δcps, we demonstrated that the cps is essential for temperature-dependent phagocytosis resistance inS. iniae, as phagocytic activity against Δcps remained unchanged across temperatures, while NS-1 showed significantly reduced uptake at HT. These findings provide new insights into the immune evasion ofS. iniaeunder thermal regulation, deepening our understanding of the thermal adaptation of aquatic bacterial pathogens.
研究领域:
微生物学
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鱼类免疫学
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分子病理学
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水产养殖疾病防控
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宿主-病原体相互作用
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环境微生物适应
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蛋白质组学
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先天免疫
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yu Guan,Rongrong Chen,Jiahui Zhu,Gaohui Sun,Qi Liu,Jingyuan Liu,Jing Yu,Zailin Yang,Jun Wang
Hydrophilic coatings are widely used in marine antifouling. Nevertheless, there are additional requirements for the robustness of marine antifouling coatings, including the ability to withstand scratches and damage. Therefore, the demand for self-healing properties and robust mechanical strength is high, presenting significant challenges. Herein, inspired by the elastic surface and exceptional water absorption capabilities of dolphins, a reversible interlocking polymer network with multiple hydrogen bonds was successfully developed. This innovation harnesses the properties of poly(urethane-urea) and ureido pyrimidinone, thereby enhancing both mechanical properties and antifouling performance. Furthermore, the modified 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was incorporated into the system as a functional filler and to serve as crosslinking points, creating a multifunctional coating. Owing to the hierarchical hydrogen bonds (the hydrogen-bonded carbonyl groups in SPPU-01 reach as high as 56.80 %), SPPU-01 exhibits exceptional strength of 17.35 MPa (1132.17 %), remarkable toughness of 89.33 MJ/m 3 , and superior tear strength of 74.97 KN/m. Upon incorporating additional components, the composite crosslinking network enhances hydrophilicity (∼29.15°), thereby forming a hydration layer that effectively prevents fouling. The SPPU-02 reveals outstanding resistance to marine bacteria, effective anti-diatom adhesion, robust anti-mussel attachment, and strong anti-pseudo-barnacle properties, achieving 96.5 %, 94.5 %, 96.04 %, and 1.31 MPa, respectively. Furthermore, this strategy, which mimics dolphin functions, is well-suited for various marine materials with different requirements. It exhibits deicing (21.22 kPa), drag reduction, and high-temperature resistance properties (69.1 %), opening new avenues for the development of antifouling coatings with both strong and superior comprehensive performance.
研究领域:
海洋涂层
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材料科学
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仿生学
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高分子科学
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表面工程
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防污技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）