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Shot peening (SP) treatment is a common surface treatment used to enhance the mechanical properties and stress corrosion resistance of components. However, accurately measuring the mechanical properties of the thin surface deformation layer using conventional techniques is challenging. This study addresses this limitation using an in-situ X-ray diffraction (XRD) test technique in combination with a micro-tensile tester to determine the thin surface layer mechanical properties of the shot-peened Mg-8Gd-8Y (GW83) alloy. The results demonstrated that SP developed a gradient-strengthened layer with ultrafine grains near the surface layer. The minimum domain size was 51 nm using the modified Williamson–Hall method. The yield strength of the strengthened layer was 24% higher than that of the matrix material. The relaxation rule of the surface compressive residual stress (CRS) was explored under tensile–tensile cyclic loading. It was found that the CRS relaxed within five cycles and tended to be relatively stable there after. The relaxation rule was greatly affected by the initial CRS state, external stress amplitude, and cycle numbers.

Addressing the challenges for detecting underwater damage to the structures with pile foundation, this study presents the design of an adsorption-operated robotic system. Initially, a prototype is proposed for an adsorption-operated robot that is equipped with an automatic movement mechanism. To account for the disturbance of the drag force in the control system, a hydrodynamic numerical model for the detection robot is established. The numerical results of the drag force are then integrated into the control system, leading to the design of a force-redeemed active disturbance rejection controller. Furthermore, a novel detection algorithm based on the image segmentation network UNet is developed for the automatic identification of damages. The performance of the controller and detection algorithm is evaluated against traditional methods. The results indicate that the proposed force-redeemed active disturbance rejection controller outperforms traditional PID and ADR controllers in terms of overshoot and adjustment time. Moreover, the developed detection algorithm exhibits superior performance in precision, F1 score, and mean intersection over union compared to the traditional algorithms of FCN, PSPnet, Deeplabv3, and UNet. Overall, this paper advances the technology of autonomous robots for underwater detection in the structures with pile foundation.

Insect wax is a traditional Chinese medicine, which can be converted into policosanol through a reduction reaction. The efficacy of policosanol from insect wax (PIW) depends on its purity and composition ratio. Plant-derived policosanol has a hypolipidemic effect, however, the effects of PIW on serum lipid levels have not yet been clarified. In this study, we investigated the effects of orally administered PIW on lipid metabolism in rats fed a high-fat diet. We found that PIW administration reduced the serum lipid levels of rats fed a high-fat diet, ameliorated body weight gain, and alleviated liver fat accumulation. This effect could be associated with the upregulation of fatty acid breakdown- and lipid metabolism–related genes, Pparα and Pparβ/δ, downregulation of fatty acid absorption and storage-related genes, Srebp1c, Il6, and Tnfα, and an antioxidant effect. These findings suggest the potential utility of PIW for developing functional foods with lipid-lowering capabilities.

The compressive residual stress field (CRSF) relaxes during the fatigue crack growth (FCG) process, and the pattern of this relaxation remains unclear. Residual stress (RS) relaxation leads to a change in residual stress intensity factor (RSIF), which significantly affects the fatigue crack growth rate (FCGR) and thus affects the assessment of fatigue crack growth rate. To this end, this work designed a series of experiments to explore the FCG behaviour in compressive residual stress fields (CRSFs) by considering RS relaxation. Firstly, shot peening(SP) treatments were conducted on the specimens. Then, residual stress fields (RSFs) at different crack propagation stages were measured to analyse the relationship between surface RS and inner RSF distribution. The derived weight function and the real-time RSF are combined to calculate the RSIF with/without considering RS relaxation. Finally, the effect of RS relaxation on the accuracy of FCGR assessment was investigated. The results show that the positive effect of CRS on the fatigue performance of the peened specimens is primarily embodied in the early stage of the FCG process. With the continuous relaxation of the CRSF, the difference in FCGR between the peened and unpeened specimens gradually decreases and tends to disappear. When the applied SIFs are large enough, the CRS would completely relax, and the inhibiting effect of CRSF on FCGR would fail. The proposed method in this work can effectively predict the FCGR of the peened specimen when considering the RS relaxation. This work could provide some meaningful insights for the assessment method of FCGR prediction in CRSF induced by surface strengthening treatment.

Abstract This article aims to detect the effect of SAM domain, SH3 domain, and nuclear localization signal 1 (SAMSN1) in neonatal rats with neurological dysfunction induced by hypoxia and ischemia (HI). The HI model was created using 7‐day postnatal rats. Zea‐longa score was utilized to validate the neurological injury after HI. Then, the differentially expressed genes (DEGs) were detected by gene sequencing and bioinformatics analysis methods. The oxygen and glucose deprivation (OGD) models were established in the SY5Y cells and fetal human cortical neurons. In addition, SAMSN1‐small interfering RNA, methyl thiazolyl tetrazolium assay, and cell growth curve were employed to evaluate the cell viability variation. Obviously, Zea‐longa scores increased in rats with HI insult. Subsequently, SAMSN1 was screened out, and it was found that SAMSN1 was strikingly upregulated in SY5Y cells and fetal neurons post‐OGD. Interestingly, we found that SAMSN1 silencing could markedly enhance cell viability and cell growth after OGD. These data suggested that downregulation of SAMSN1 may exert a neuroprotective effect on damaged neurons after HI by improving cell viability and cell survival, which provides a potential theoretical basis for clinical trials in the future to treat neonatal hypoxic–ischemic encephalopathy.

Abstract Background Vacuolar protein sorting (VPS) plays a crucial role in intracellular molecular transport between organelles. However, studies have indicated a correlation between VPSs and tumorigenesis and the development of several cancers. Nevertheless, the association between VPSs and hepatocellular carcinoma (HCC) remains unclear. Methods By analyzing databases such as The Cancer Genome Atlas (TCGA) and The International Cancer Genome Consortium (ICGC), we investigated the differences in VPSs expression between normal tissue and HCC transcriptomes. Furthermore, we examined the relationship between VPSs expression and overall survival (OS) in patients with HCC. Univariate and multivariate Cox analyses were employed to assess the prognostic value of VPS72 as an independent factor, and the correlation between VPS72 and the tumor immune microenvironment was also analyzed. Results We observed significant overexpression of 28 VPSs in HCC tissues compared to normal tissues. The mRNA expression of VPSs displayed a negative correlation with OS, while exhibiting a positive correlation with tumor grade and stage. Additionally, both univariate and multivariate Cox analyses identified VPS72 as a potential independent risk factor for HCC prognosis. Overexpression of VPS72 demonstrated a positive correlation with various clinicopathological factors associated with poor prognosis, as well as the infiltration levels of immune cells. Conclusion Therefore, our research shows that VPSs participate in HCC occurrence and development, especially VPS72, which may act as a potential target for HCC treatment and prognosis biomarker.

The identification of longitudinal bending moments is a critical component in the health monitoring of ship structures. This study examines the effect of the failure of measurement points on the accuracy of bending moment identification and presents a solution using an XGboost fitting method. The impact of failure point position and quantity on strain fitting accuracy and bending moment identification was investigated by performing a four-point bending experiment in typical failure scenarios. Further numerical analysis was conducted to identify potential sources of errors in the measurement process. Additionally, several XGBoost-based fitting schemes were tested under practical conditions to provide reliable fitting suggestions. The results indicated that the XGboost strain fitting method outperforms conventional methods for removing failed measurement points, resulting in improved accuracy of identification. When the most critical failure condition occurs (i.e., the deck plate measurement points and deck stiffener measurement points fail), the XGboost method can still estimate the strain at the failure points with acceptable accuracy. These results also hold in complex load scenarios. Moreover, in the practical measurement conditions, the arrangement of measuring points includes two sections that are sufficient to support the fitting of failed measurement points by using the XGboost method. The XGboost strain fitting method exhibits promising potential in strain fitting applications.

Due to the tall and large superstructures of cruise ships, the wind-induced vibration of frame structure on open decks cannot be neglected. This study investigated the wind-induced vibration of a typical frame structure on a cruise ship by using wind tunnel tests and numerical simulations. Wind tunnel tests were conducted to explore the simulation methods of the fluid–structure interaction (FSI). CFD simulations were performed to obtain the wind field data of the entire ship, which was utilized as an input for the open deck through the subdomain method. Subsequently, wind-induced vibration simulations of the guide rail frame structure on the open deck was carried out under various wind conditions. The results revealed that employing the turbulence model SST k-ω had a good agreement with the experimental data. The entire ship’s CFD results have a significant impact on the subdomain’s wind-induced vibration results. The vibration frequency of the guide rail frame structure was mainly concentrated between 0.8–10.1 Hz. The most unfavorable conditions appear at the wind attack angles of 0° and 120°. This study can provide some instructive insights for the prediction of wind-induced vibration and control of typical structures on the open decks of large cruise ships.

ABSTRACT: Evaluating velocity-porosity relationships of hydrate-bearing marine sediments is essential for characterizing natural gas hydrates below seafloor as either a potential energy resource or geohazards risks. Four sites had cored using pressure and non-pressure methods during the gas hydrates drilling project (GMGS4) expedition at Shenhu Area, north slope of the South China Sea. Sediments were cored above, below, and through the gas-hydrate-bearing zone guided with logging-while-drilling analysis results. Gamma density and P-wave velocity were measured in each pressure core before subsampling. Methane hydrates volumes in total 62 samples were calculated from the moles of excess methane collected during depressurization experiments. The concentration of methane hydrates ranged from 0.3% to 32.3%. The concentrations of pore fluid (25.44% to 68.82%) and sediments (23.63% to 54.28%) were calculated from the gamma density. The regression models of P-wave velocity were derived and compared with a global empirical equation derived from shallow, unconsolidated sediments data. The results were close to the global trend when the fluid concentration is larger than the critical porosity. It is concluded that the dominant factor of P-wave velocity in hydrate-bearing marine sediments is the presence of the hydrate. Methane hydrates can reduce the fluid concentration by discharging the pore fluid and occupying the original pore space of sediments after its formation.©2022 China Geology Editorial Office.

Third-party adolescents (those aware of peer conflict as neither aggressors nor victims) can help shape their peers' emotional responses to perceived victimization. Emotion regulation promotes resilience for those who have been victimized, and heightened anger can exacerbate negative outcomes. This study sought to understand how ethnically diverse victimized adolescents described third-party actions that amplified their anger and calmed their emotions--and whether there were gender, racial/ethnic, or school-level patterns. Data were drawn from 264 structured interviews using a multi-method, repeated measures design. Participants were 66 African Americans, 57 European Americans, 64 Mexican Americans, and 77 Native Americans from the Northwest United States. Open- and process-coding identified 16 themes that described third-party actions, and pattern coding provided insight into why particular actions may be perceived as anger-amplifying or calming. Wilcoxon Signed Rank tests on action frequencies revealed five actions (e.g., co-ruminating) that were associated with amplifying victims' anger and eight actions (e.g., reassuring) that were associated with calming victims' emotions. Group patterns were examined using chi-square and Mann-Whitney tests. Programs and interventions may draw on these qualitative accounts of victimized adolescents' experiences to illustrate how third-party actions might differentially impact peers during or after aggressive incidents.

ObjectivesThe perforate high web structure is a special structure widely used in the superstructures of large cruise ships. In order to establish the design method of this kind of structure, it is necessary to fully grasp the mechanical characteristics of typical perforated high web structures used in the superstructures of large cruise ships.MethodsUsing the nonlinear finite element theory and classical stiffened plate theory, an analysis is made of the influence law of initial deck defects, longitudinal girder specifications and web openings on the ultimate bearing capacity of the plate frame under longitudinal compression.ResultsThe thin plate frame is more sensitive to initial defects, and the initial deformation mode is different from that of the thick plate frame. The longitudinal girder ultimate capacity contribution is bigger and the sensitivity of longitudinal pressure limit capacity to the proportion and shape of holes is low. The locations of the collapse failure buckling zones are determined by the locations of the holes. The failure modes of perforated high web frame structures are revealed.ConclusionsThe results of the influence law of key factors such as initial deck defects, geometrical dimensions of longitudinal girders and web openings on the ultimate strength of perforated high web frame structures provide guidance for the lightweight design and safety assessment of cruise ship superstructures.

Owing to their excellent physical characteristics of lightweightiness, compactness and rapid deployment, the inflated membrane structures satisfy the demands of maritime salvage and military transportation for long-distance delivery and rapid response. Exploring the failure behaviour of inflated membrane structures can greatly contribute to their widespread applications in ocean engineering. In this research, the main objective is to comprehensively investigate the bending and failure behaviour of inflated membrane structures. Thus, the Surface-Based Fluid Cavity method is employed to set up the finite element model (FEM) which is compared to the experimental results to verify its reliability. In parallel, the effects of internal pressure and wrinkles are discussed. An empirical expression of the ultimate bending loading was fitted by face-centred composite designs of the Response Surface Methodology. The results of experiments and FEM show that the bearing capacity of the inflated membrane structure is positively correlated with the internal pressure but decreased obviously with the occurrence and propagation of wrinkles. The deformation behaviour and the stress distribution are similar to those of the traditional four-point bending beam, and the local instability induced by wrinkles will cause structural failure. In addition, the numerical model and the proposed expression showed deviations below 5% in relation to the experimental measures. Therefore, the FEM and proposed expression are high of reliability and have important engineering guiding significance for the application of inflated membrane structures in ocean engineering.